1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Mellanox BlueField I2C bus driver
4 *
5 * Copyright (C) 2020 Mellanox Technologies, Ltd.
6 */
7
8 #include <linux/acpi.h>
9 #include <linux/bitfield.h>
10 #include <linux/delay.h>
11 #include <linux/err.h>
12 #include <linux/interrupt.h>
13 #include <linux/i2c.h>
14 #include <linux/io.h>
15 #include <linux/iopoll.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/mutex.h>
19 #include <linux/of.h>
20 #include <linux/platform_device.h>
21 #include <linux/string.h>
22
23 /* Defines what functionality is present. */
24 #define MLXBF_I2C_FUNC_SMBUS_BLOCK \
25 (I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL)
26
27 #define MLXBF_I2C_FUNC_SMBUS_DEFAULT \
28 (I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA | \
29 I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_I2C_BLOCK | \
30 I2C_FUNC_SMBUS_PROC_CALL)
31
32 #define MLXBF_I2C_FUNC_ALL \
33 (MLXBF_I2C_FUNC_SMBUS_DEFAULT | MLXBF_I2C_FUNC_SMBUS_BLOCK | \
34 I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SLAVE)
35
36 /* Shared resources info in BlueField platforms. */
37
38 #define MLXBF_I2C_COALESCE_TYU_ADDR 0x02801300
39 #define MLXBF_I2C_COALESCE_TYU_SIZE 0x010
40
41 #define MLXBF_I2C_GPIO_TYU_ADDR 0x02802000
42 #define MLXBF_I2C_GPIO_TYU_SIZE 0x100
43
44 #define MLXBF_I2C_COREPLL_TYU_ADDR 0x02800358
45 #define MLXBF_I2C_COREPLL_TYU_SIZE 0x008
46
47 #define MLXBF_I2C_COREPLL_YU_ADDR 0x02800c30
48 #define MLXBF_I2C_COREPLL_YU_SIZE 0x00c
49
50 #define MLXBF_I2C_COREPLL_RSH_YU_ADDR 0x13409824
51 #define MLXBF_I2C_COREPLL_RSH_YU_SIZE 0x00c
52
53 #define MLXBF_I2C_SHARED_RES_MAX 3
54
55 /*
56 * Note that the following SMBus, CAUSE, GPIO and PLL register addresses
57 * refer to their respective offsets relative to the corresponding
58 * memory-mapped region whose addresses are specified in either the DT or
59 * the ACPI tables or above.
60 */
61
62 /*
63 * SMBus Master core clock frequency. Timing configurations are
64 * strongly dependent on the core clock frequency of the SMBus
65 * Master. Default value is set to 400MHz.
66 */
67 #define MLXBF_I2C_TYU_PLL_OUT_FREQ (400 * 1000 * 1000)
68 /* Reference clock for Bluefield - 156 MHz. */
69 #define MLXBF_I2C_PLL_IN_FREQ 156250000ULL
70
71 /* Constant used to determine the PLL frequency. */
72 #define MLNXBF_I2C_COREPLL_CONST 16384ULL
73
74 #define MLXBF_I2C_FREQUENCY_1GHZ 1000000000ULL
75
76 /* PLL registers. */
77 #define MLXBF_I2C_CORE_PLL_REG1 0x4
78 #define MLXBF_I2C_CORE_PLL_REG2 0x8
79
80 /* OR cause register. */
81 #define MLXBF_I2C_CAUSE_OR_EVTEN0 0x14
82 #define MLXBF_I2C_CAUSE_OR_CLEAR 0x18
83
84 /* Arbiter Cause Register. */
85 #define MLXBF_I2C_CAUSE_ARBITER 0x1c
86
87 /*
88 * Cause Status flags. Note that those bits might be considered
89 * as interrupt enabled bits.
90 */
91
92 /* Transaction ended with STOP. */
93 #define MLXBF_I2C_CAUSE_TRANSACTION_ENDED BIT(0)
94 /* Master arbitration lost. */
95 #define MLXBF_I2C_CAUSE_M_ARBITRATION_LOST BIT(1)
96 /* Unexpected start detected. */
97 #define MLXBF_I2C_CAUSE_UNEXPECTED_START BIT(2)
98 /* Unexpected stop detected. */
99 #define MLXBF_I2C_CAUSE_UNEXPECTED_STOP BIT(3)
100 /* Wait for transfer continuation. */
101 #define MLXBF_I2C_CAUSE_WAIT_FOR_FW_DATA BIT(4)
102 /* Failed to generate STOP. */
103 #define MLXBF_I2C_CAUSE_PUT_STOP_FAILED BIT(5)
104 /* Failed to generate START. */
105 #define MLXBF_I2C_CAUSE_PUT_START_FAILED BIT(6)
106 /* Clock toggle completed. */
107 #define MLXBF_I2C_CAUSE_CLK_TOGGLE_DONE BIT(7)
108 /* Transfer timeout occurred. */
109 #define MLXBF_I2C_CAUSE_M_FW_TIMEOUT BIT(8)
110 /* Master busy bit reset. */
111 #define MLXBF_I2C_CAUSE_M_GW_BUSY_FALL BIT(9)
112
113 #define MLXBF_I2C_CAUSE_MASTER_ARBITER_BITS_MASK GENMASK(9, 0)
114
115 #define MLXBF_I2C_CAUSE_MASTER_STATUS_ERROR \
116 (MLXBF_I2C_CAUSE_M_ARBITRATION_LOST | \
117 MLXBF_I2C_CAUSE_UNEXPECTED_START | \
118 MLXBF_I2C_CAUSE_UNEXPECTED_STOP | \
119 MLXBF_I2C_CAUSE_PUT_STOP_FAILED | \
120 MLXBF_I2C_CAUSE_PUT_START_FAILED | \
121 MLXBF_I2C_CAUSE_CLK_TOGGLE_DONE | \
122 MLXBF_I2C_CAUSE_M_FW_TIMEOUT)
123
124 /*
125 * Slave cause status flags. Note that those bits might be considered
126 * as interrupt enabled bits.
127 */
128
129 /* Write transaction received successfully. */
130 #define MLXBF_I2C_CAUSE_WRITE_SUCCESS BIT(0)
131 /* Read transaction received, waiting for response. */
132 #define MLXBF_I2C_CAUSE_READ_WAIT_FW_RESPONSE BIT(13)
133 /* Slave busy bit reset. */
134 #define MLXBF_I2C_CAUSE_S_GW_BUSY_FALL BIT(18)
135
136 /* Cause coalesce registers. */
137 #define MLXBF_I2C_CAUSE_COALESCE_0 0x00
138
139 #define MLXBF_I2C_CAUSE_TYU_SLAVE_BIT 3
140 #define MLXBF_I2C_CAUSE_YU_SLAVE_BIT 1
141
142 /* Functional enable register. */
143 #define MLXBF_I2C_GPIO_0_FUNC_EN_0 0x28
144 /* Force OE enable register. */
145 #define MLXBF_I2C_GPIO_0_FORCE_OE_EN 0x30
146 /*
147 * Note that Smbus GWs are on GPIOs 30:25. Two pins are used to control
148 * SDA/SCL lines:
149 *
150 * SMBUS GW0 -> bits[26:25]
151 * SMBUS GW1 -> bits[28:27]
152 * SMBUS GW2 -> bits[30:29]
153 */
154 #define MLXBF_I2C_GPIO_SMBUS_GW_PINS(num) (25 + ((num) << 1))
155
156 /* Note that gw_id can be 0,1 or 2. */
157 #define MLXBF_I2C_GPIO_SMBUS_GW_MASK(num) \
158 (0xffffffff & (~(0x3 << MLXBF_I2C_GPIO_SMBUS_GW_PINS(num))))
159
160 #define MLXBF_I2C_GPIO_SMBUS_GW_RESET_PINS(num, val) \
161 ((val) & MLXBF_I2C_GPIO_SMBUS_GW_MASK(num))
162
163 #define MLXBF_I2C_GPIO_SMBUS_GW_ASSERT_PINS(num, val) \
164 ((val) | (0x3 << MLXBF_I2C_GPIO_SMBUS_GW_PINS(num)))
165
166 /*
167 * Defines SMBus operating frequency and core clock frequency.
168 * According to ADB files, default values are compliant to 100KHz SMBus
169 * @ 400MHz core clock. The driver should be able to calculate core
170 * frequency based on PLL parameters.
171 */
172 #define MLXBF_I2C_COREPLL_FREQ MLXBF_I2C_TYU_PLL_OUT_FREQ
173
174 /* Core PLL TYU configuration. */
175 #define MLXBF_I2C_COREPLL_CORE_F_TYU_MASK GENMASK(15, 3)
176 #define MLXBF_I2C_COREPLL_CORE_OD_TYU_MASK GENMASK(19, 16)
177 #define MLXBF_I2C_COREPLL_CORE_R_TYU_MASK GENMASK(25, 20)
178
179 /* Core PLL YU configuration. */
180 #define MLXBF_I2C_COREPLL_CORE_F_YU_MASK GENMASK(25, 0)
181 #define MLXBF_I2C_COREPLL_CORE_OD_YU_MASK GENMASK(3, 0)
182 #define MLXBF_I2C_COREPLL_CORE_R_YU_MASK GENMASK(31, 26)
183
184 /* SMBus timing parameters. */
185 #define MLXBF_I2C_SMBUS_TIMER_SCL_LOW_SCL_HIGH 0x00
186 #define MLXBF_I2C_SMBUS_TIMER_FALL_RISE_SPIKE 0x04
187 #define MLXBF_I2C_SMBUS_TIMER_THOLD 0x08
188 #define MLXBF_I2C_SMBUS_TIMER_TSETUP_START_STOP 0x0c
189 #define MLXBF_I2C_SMBUS_TIMER_TSETUP_DATA 0x10
190 #define MLXBF_I2C_SMBUS_THIGH_MAX_TBUF 0x14
191 #define MLXBF_I2C_SMBUS_SCL_LOW_TIMEOUT 0x18
192
193 #define MLXBF_I2C_SHIFT_0 0
194 #define MLXBF_I2C_SHIFT_8 8
195 #define MLXBF_I2C_SHIFT_16 16
196 #define MLXBF_I2C_SHIFT_24 24
197
198 #define MLXBF_I2C_MASK_8 GENMASK(7, 0)
199 #define MLXBF_I2C_MASK_16 GENMASK(15, 0)
200
201 #define MLXBF_I2C_MST_ADDR_OFFSET 0x200
202
203 /* SMBus Master GW. */
204 #define MLXBF_I2C_SMBUS_MASTER_GW 0x0
205 /* Number of bytes received and sent. */
206 #define MLXBF_I2C_YU_SMBUS_RS_BYTES 0x100
207 #define MLXBF_I2C_RSH_YU_SMBUS_RS_BYTES 0x10c
208 /* Packet error check (PEC) value. */
209 #define MLXBF_I2C_SMBUS_MASTER_PEC 0x104
210 /* Status bits (ACK/NACK/FW Timeout). */
211 #define MLXBF_I2C_SMBUS_MASTER_STATUS 0x108
212 /* SMbus Master Finite State Machine. */
213 #define MLXBF_I2C_YU_SMBUS_MASTER_FSM 0x110
214 #define MLXBF_I2C_RSH_YU_SMBUS_MASTER_FSM 0x100
215
216 /* SMBus master GW control bits offset in MLXBF_I2C_SMBUS_MASTER_GW[31:3]. */
217 #define MLXBF_I2C_MASTER_LOCK_BIT BIT(31) /* Lock bit. */
218 #define MLXBF_I2C_MASTER_BUSY_BIT BIT(30) /* Busy bit. */
219 #define MLXBF_I2C_MASTER_START_BIT BIT(29) /* Control start. */
220 #define MLXBF_I2C_MASTER_CTL_WRITE_BIT BIT(28) /* Control write phase. */
221 #define MLXBF_I2C_MASTER_CTL_READ_BIT BIT(19) /* Control read phase. */
222 #define MLXBF_I2C_MASTER_STOP_BIT BIT(3) /* Control stop. */
223
224 #define MLXBF_I2C_MASTER_ENABLE \
225 (MLXBF_I2C_MASTER_LOCK_BIT | MLXBF_I2C_MASTER_BUSY_BIT | \
226 MLXBF_I2C_MASTER_START_BIT | MLXBF_I2C_MASTER_STOP_BIT)
227
228 #define MLXBF_I2C_MASTER_ENABLE_WRITE \
229 (MLXBF_I2C_MASTER_ENABLE | MLXBF_I2C_MASTER_CTL_WRITE_BIT)
230
231 #define MLXBF_I2C_MASTER_ENABLE_READ \
232 (MLXBF_I2C_MASTER_ENABLE | MLXBF_I2C_MASTER_CTL_READ_BIT)
233
234 #define MLXBF_I2C_MASTER_WRITE_SHIFT 21 /* Control write bytes */
235 #define MLXBF_I2C_MASTER_SEND_PEC_SHIFT 20 /* Send PEC byte when set to 1 */
236 #define MLXBF_I2C_MASTER_PARSE_EXP_SHIFT 11 /* Control parse expected bytes */
237 #define MLXBF_I2C_MASTER_SLV_ADDR_SHIFT 12 /* Slave address */
238 #define MLXBF_I2C_MASTER_READ_SHIFT 4 /* Control read bytes */
239
240 /* SMBus master GW Data descriptor. */
241 #define MLXBF_I2C_MASTER_DATA_DESC_ADDR 0x80
242 #define MLXBF_I2C_MASTER_DATA_DESC_SIZE 0x80 /* Size in bytes. */
243
244 /* Maximum bytes to read/write per SMBus transaction. */
245 #define MLXBF_I2C_MASTER_DATA_R_LENGTH MLXBF_I2C_MASTER_DATA_DESC_SIZE
246 #define MLXBF_I2C_MASTER_DATA_W_LENGTH (MLXBF_I2C_MASTER_DATA_DESC_SIZE - 1)
247
248 /* All bytes were transmitted. */
249 #define MLXBF_I2C_SMBUS_STATUS_BYTE_CNT_DONE BIT(0)
250 /* NACK received. */
251 #define MLXBF_I2C_SMBUS_STATUS_NACK_RCV BIT(1)
252 /* Slave's byte count >128 bytes. */
253 #define MLXBF_I2C_SMBUS_STATUS_READ_ERR BIT(2)
254 /* Timeout occurred. */
255 #define MLXBF_I2C_SMBUS_STATUS_FW_TIMEOUT BIT(3)
256
257 #define MLXBF_I2C_SMBUS_MASTER_STATUS_MASK GENMASK(3, 0)
258
259 #define MLXBF_I2C_SMBUS_MASTER_STATUS_ERROR \
260 (MLXBF_I2C_SMBUS_STATUS_NACK_RCV | \
261 MLXBF_I2C_SMBUS_STATUS_READ_ERR | \
262 MLXBF_I2C_SMBUS_STATUS_FW_TIMEOUT)
263
264 #define MLXBF_I2C_SMBUS_MASTER_FSM_STOP_MASK BIT(31)
265 #define MLXBF_I2C_SMBUS_MASTER_FSM_PS_STATE_MASK BIT(15)
266
267 #define MLXBF_I2C_SLV_ADDR_OFFSET 0x400
268
269 /* SMBus slave GW. */
270 #define MLXBF_I2C_SMBUS_SLAVE_GW 0x0
271 /* Number of bytes received and sent from/to master. */
272 #define MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES 0x100
273 /* Packet error check (PEC) value. */
274 #define MLXBF_I2C_SMBUS_SLAVE_PEC 0x104
275 /* SMBus slave Finite State Machine (FSM). */
276 #define MLXBF_I2C_SMBUS_SLAVE_FSM 0x110
277 /*
278 * Should be set when all raised causes handled, and cleared by HW on
279 * every new cause.
280 */
281 #define MLXBF_I2C_SMBUS_SLAVE_READY 0x12c
282
283 /* SMBus slave GW control bits offset in MLXBF_I2C_SMBUS_SLAVE_GW[31:19]. */
284 #define MLXBF_I2C_SLAVE_BUSY_BIT BIT(30) /* Busy bit. */
285 #define MLXBF_I2C_SLAVE_WRITE_BIT BIT(29) /* Control write enable. */
286
287 #define MLXBF_I2C_SLAVE_ENABLE \
288 (MLXBF_I2C_SLAVE_BUSY_BIT | MLXBF_I2C_SLAVE_WRITE_BIT)
289
290 #define MLXBF_I2C_SLAVE_WRITE_BYTES_SHIFT 22 /* Number of bytes to write. */
291 #define MLXBF_I2C_SLAVE_SEND_PEC_SHIFT 21 /* Send PEC byte shift. */
292
293 /* SMBus slave GW Data descriptor. */
294 #define MLXBF_I2C_SLAVE_DATA_DESC_ADDR 0x80
295 #define MLXBF_I2C_SLAVE_DATA_DESC_SIZE 0x80 /* Size in bytes. */
296
297 /* SMbus slave configuration registers. */
298 #define MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG 0x114
299 #define MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT 16
300 #define MLXBF_I2C_SMBUS_SLAVE_ADDR_EN_BIT BIT(7)
301 #define MLXBF_I2C_SMBUS_SLAVE_ADDR_MASK GENMASK(6, 0)
302
303 /*
304 * Timeout is given in microsends. Note also that timeout handling is not
305 * exact.
306 */
307 #define MLXBF_I2C_SMBUS_TIMEOUT (300 * 1000) /* 300ms */
308 #define MLXBF_I2C_SMBUS_LOCK_POLL_TIMEOUT (300 * 1000) /* 300ms */
309
310 /* Polling frequency in microseconds. */
311 #define MLXBF_I2C_POLL_FREQ_IN_USEC 200
312
313 #define MLXBF_I2C_SMBUS_OP_CNT_1 1
314 #define MLXBF_I2C_SMBUS_OP_CNT_2 2
315 #define MLXBF_I2C_SMBUS_OP_CNT_3 3
316 #define MLXBF_I2C_SMBUS_MAX_OP_CNT MLXBF_I2C_SMBUS_OP_CNT_3
317
318 /* Helper macro to define an I2C resource parameters. */
319 #define MLXBF_I2C_RES_PARAMS(addr, size, str) \
320 { \
321 .start = (addr), \
322 .end = (addr) + (size) - 1, \
323 .name = (str) \
324 }
325
326 enum {
327 MLXBF_I2C_TIMING_100KHZ = 100000,
328 MLXBF_I2C_TIMING_400KHZ = 400000,
329 MLXBF_I2C_TIMING_1000KHZ = 1000000,
330 };
331
332 enum {
333 MLXBF_I2C_F_READ = BIT(0),
334 MLXBF_I2C_F_WRITE = BIT(1),
335 MLXBF_I2C_F_NORESTART = BIT(3),
336 MLXBF_I2C_F_SMBUS_OPERATION = BIT(4),
337 MLXBF_I2C_F_SMBUS_BLOCK = BIT(5),
338 MLXBF_I2C_F_SMBUS_PEC = BIT(6),
339 MLXBF_I2C_F_SMBUS_PROCESS_CALL = BIT(7),
340 };
341
342 /* Mellanox BlueField chip type. */
343 enum mlxbf_i2c_chip_type {
344 MLXBF_I2C_CHIP_TYPE_1, /* Mellanox BlueField-1 chip. */
345 MLXBF_I2C_CHIP_TYPE_2, /* Mellanox BlueField-2 chip. */
346 MLXBF_I2C_CHIP_TYPE_3 /* Mellanox BlueField-3 chip. */
347 };
348
349 /* List of chip resources that are being accessed by the driver. */
350 enum {
351 MLXBF_I2C_SMBUS_RES,
352 MLXBF_I2C_MST_CAUSE_RES,
353 MLXBF_I2C_SLV_CAUSE_RES,
354 MLXBF_I2C_COALESCE_RES,
355 MLXBF_I2C_SMBUS_TIMER_RES,
356 MLXBF_I2C_SMBUS_MST_RES,
357 MLXBF_I2C_SMBUS_SLV_RES,
358 MLXBF_I2C_COREPLL_RES,
359 MLXBF_I2C_GPIO_RES,
360 MLXBF_I2C_END_RES
361 };
362
363 /* Encapsulates timing parameters. */
364 struct mlxbf_i2c_timings {
365 u16 scl_high; /* Clock high period. */
366 u16 scl_low; /* Clock low period. */
367 u8 sda_rise; /* Data rise time. */
368 u8 sda_fall; /* Data fall time. */
369 u8 scl_rise; /* Clock rise time. */
370 u8 scl_fall; /* Clock fall time. */
371 u16 hold_start; /* Hold time after (REPEATED) START. */
372 u16 hold_data; /* Data hold time. */
373 u16 setup_start; /* REPEATED START condition setup time. */
374 u16 setup_stop; /* STOP condition setup time. */
375 u16 setup_data; /* Data setup time. */
376 u16 pad; /* Padding. */
377 u16 buf; /* Bus free time between STOP and START. */
378 u16 thigh_max; /* Thigh max. */
379 u32 timeout; /* Detect clock low timeout. */
380 };
381
382 struct mlxbf_i2c_smbus_operation {
383 u32 flags;
384 u32 length; /* Buffer length in bytes. */
385 u8 *buffer;
386 };
387
388 struct mlxbf_i2c_smbus_request {
389 u8 slave;
390 u8 operation_cnt;
391 struct mlxbf_i2c_smbus_operation operation[MLXBF_I2C_SMBUS_MAX_OP_CNT];
392 };
393
394 struct mlxbf_i2c_resource {
395 void __iomem *io;
396 struct resource *params;
397 struct mutex *lock; /* Mutex to protect mlxbf_i2c_resource. */
398 u8 type;
399 };
400
401 struct mlxbf_i2c_chip_info {
402 enum mlxbf_i2c_chip_type type;
403 /* Chip shared resources that are being used by the I2C controller. */
404 struct mlxbf_i2c_resource *shared_res[MLXBF_I2C_SHARED_RES_MAX];
405
406 /* Callback to calculate the core PLL frequency. */
407 u64 (*calculate_freq)(struct mlxbf_i2c_resource *corepll_res);
408
409 /* Registers' address offset */
410 u32 smbus_master_rs_bytes_off;
411 u32 smbus_master_fsm_off;
412 };
413
414 struct mlxbf_i2c_priv {
415 const struct mlxbf_i2c_chip_info *chip;
416 struct i2c_adapter adap;
417 struct mlxbf_i2c_resource *smbus;
418 struct mlxbf_i2c_resource *timer;
419 struct mlxbf_i2c_resource *mst;
420 struct mlxbf_i2c_resource *slv;
421 struct mlxbf_i2c_resource *mst_cause;
422 struct mlxbf_i2c_resource *slv_cause;
423 struct mlxbf_i2c_resource *coalesce;
424 u64 frequency; /* Core frequency in Hz. */
425 int bus; /* Physical bus identifier. */
426 int irq;
427 struct i2c_client *slave[MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT];
428 u32 resource_version;
429 };
430
431 /* Core PLL frequency. */
432 static u64 mlxbf_i2c_corepll_frequency;
433
434 static struct resource mlxbf_i2c_coalesce_tyu_params =
435 MLXBF_I2C_RES_PARAMS(MLXBF_I2C_COALESCE_TYU_ADDR,
436 MLXBF_I2C_COALESCE_TYU_SIZE,
437 "COALESCE_MEM");
438 static struct resource mlxbf_i2c_corepll_tyu_params =
439 MLXBF_I2C_RES_PARAMS(MLXBF_I2C_COREPLL_TYU_ADDR,
440 MLXBF_I2C_COREPLL_TYU_SIZE,
441 "COREPLL_MEM");
442 static struct resource mlxbf_i2c_corepll_yu_params =
443 MLXBF_I2C_RES_PARAMS(MLXBF_I2C_COREPLL_YU_ADDR,
444 MLXBF_I2C_COREPLL_YU_SIZE,
445 "COREPLL_MEM");
446 static struct resource mlxbf_i2c_corepll_rsh_yu_params =
447 MLXBF_I2C_RES_PARAMS(MLXBF_I2C_COREPLL_RSH_YU_ADDR,
448 MLXBF_I2C_COREPLL_RSH_YU_SIZE,
449 "COREPLL_MEM");
450 static struct resource mlxbf_i2c_gpio_tyu_params =
451 MLXBF_I2C_RES_PARAMS(MLXBF_I2C_GPIO_TYU_ADDR,
452 MLXBF_I2C_GPIO_TYU_SIZE,
453 "GPIO_MEM");
454
455 static struct mutex mlxbf_i2c_coalesce_lock;
456 static struct mutex mlxbf_i2c_corepll_lock;
457 static struct mutex mlxbf_i2c_gpio_lock;
458
459 static struct mlxbf_i2c_resource mlxbf_i2c_coalesce_res[] = {
460 [MLXBF_I2C_CHIP_TYPE_1] = {
461 .params = &mlxbf_i2c_coalesce_tyu_params,
462 .lock = &mlxbf_i2c_coalesce_lock,
463 .type = MLXBF_I2C_COALESCE_RES
464 },
465 {}
466 };
467
468 static struct mlxbf_i2c_resource mlxbf_i2c_corepll_res[] = {
469 [MLXBF_I2C_CHIP_TYPE_1] = {
470 .params = &mlxbf_i2c_corepll_tyu_params,
471 .lock = &mlxbf_i2c_corepll_lock,
472 .type = MLXBF_I2C_COREPLL_RES
473 },
474 [MLXBF_I2C_CHIP_TYPE_2] = {
475 .params = &mlxbf_i2c_corepll_yu_params,
476 .lock = &mlxbf_i2c_corepll_lock,
477 .type = MLXBF_I2C_COREPLL_RES,
478 },
479 [MLXBF_I2C_CHIP_TYPE_3] = {
480 .params = &mlxbf_i2c_corepll_rsh_yu_params,
481 .lock = &mlxbf_i2c_corepll_lock,
482 .type = MLXBF_I2C_COREPLL_RES,
483 }
484 };
485
486 static struct mlxbf_i2c_resource mlxbf_i2c_gpio_res[] = {
487 [MLXBF_I2C_CHIP_TYPE_1] = {
488 .params = &mlxbf_i2c_gpio_tyu_params,
489 .lock = &mlxbf_i2c_gpio_lock,
490 .type = MLXBF_I2C_GPIO_RES
491 },
492 {}
493 };
494
495 static u8 mlxbf_i2c_bus_count;
496
497 static struct mutex mlxbf_i2c_bus_lock;
498
mlxbf_i2c_smbus_transaction_success(u32 master_status,u32 cause_status)499 static bool mlxbf_i2c_smbus_transaction_success(u32 master_status,
500 u32 cause_status)
501 {
502 /*
503 * When transaction ended with STOP, all bytes were transmitted,
504 * and no NACK received, then the transaction ended successfully.
505 * On the other hand, when the GW is configured with the stop bit
506 * de-asserted then the SMBus expects the following GW configuration
507 * for transfer continuation.
508 */
509 if ((cause_status & MLXBF_I2C_CAUSE_WAIT_FOR_FW_DATA) ||
510 ((cause_status & MLXBF_I2C_CAUSE_TRANSACTION_ENDED) &&
511 (master_status & MLXBF_I2C_SMBUS_STATUS_BYTE_CNT_DONE) &&
512 !(master_status & MLXBF_I2C_SMBUS_STATUS_NACK_RCV)))
513 return true;
514
515 return false;
516 }
517
518 /*
519 * Poll SMBus master status and return transaction status,
520 * i.e. whether succeeded or failed. I2C and SMBus fault codes
521 * are returned as negative numbers from most calls, with zero
522 * or some positive number indicating a non-fault return.
523 */
mlxbf_i2c_smbus_check_status(struct mlxbf_i2c_priv * priv)524 static int mlxbf_i2c_smbus_check_status(struct mlxbf_i2c_priv *priv)
525 {
526 u32 master_status_bits;
527 u32 cause_status_bits;
528 u32 bits;
529
530 /*
531 * GW busy bit is raised by the driver and cleared by the HW
532 * when the transaction is completed. The busy bit is a good
533 * indicator of transaction status. So poll the busy bit, and
534 * then read the cause and master status bits to determine if
535 * errors occurred during the transaction.
536 */
537 readl_poll_timeout_atomic(priv->mst->io + MLXBF_I2C_SMBUS_MASTER_GW,
538 bits, !(bits & MLXBF_I2C_MASTER_BUSY_BIT),
539 MLXBF_I2C_POLL_FREQ_IN_USEC, MLXBF_I2C_SMBUS_TIMEOUT);
540
541 /* Read cause status bits. */
542 cause_status_bits = readl(priv->mst_cause->io +
543 MLXBF_I2C_CAUSE_ARBITER);
544 cause_status_bits &= MLXBF_I2C_CAUSE_MASTER_ARBITER_BITS_MASK;
545
546 /*
547 * Parse both Cause and Master GW bits, then return transaction status.
548 */
549
550 master_status_bits = readl(priv->mst->io +
551 MLXBF_I2C_SMBUS_MASTER_STATUS);
552 master_status_bits &= MLXBF_I2C_SMBUS_MASTER_STATUS_MASK;
553
554 if (mlxbf_i2c_smbus_transaction_success(master_status_bits,
555 cause_status_bits))
556 return 0;
557
558 /*
559 * In case of timeout on GW busy, the ISR will clear busy bit but
560 * transaction ended bits cause will not be set so the transaction
561 * fails. Then, we must check Master GW status bits.
562 */
563 if ((master_status_bits & MLXBF_I2C_SMBUS_MASTER_STATUS_ERROR) &&
564 (cause_status_bits & (MLXBF_I2C_CAUSE_TRANSACTION_ENDED |
565 MLXBF_I2C_CAUSE_M_GW_BUSY_FALL)))
566 return -EIO;
567
568 if (cause_status_bits & MLXBF_I2C_CAUSE_MASTER_STATUS_ERROR)
569 return -EAGAIN;
570
571 return -ETIMEDOUT;
572 }
573
mlxbf_i2c_smbus_write_data(struct mlxbf_i2c_priv * priv,const u8 * data,u8 length,u32 addr,bool is_master)574 static void mlxbf_i2c_smbus_write_data(struct mlxbf_i2c_priv *priv,
575 const u8 *data, u8 length, u32 addr,
576 bool is_master)
577 {
578 u8 offset, aligned_length;
579 u32 data32;
580
581 aligned_length = round_up(length, 4);
582
583 /*
584 * Copy data bytes from 4-byte aligned source buffer.
585 * Data copied to the Master GW Data Descriptor MUST be shifted
586 * left so the data starts at the MSB of the descriptor registers
587 * as required by the underlying hardware. Enable byte swapping
588 * when writing data bytes to the 32 * 32-bit HW Data registers
589 * a.k.a Master GW Data Descriptor.
590 */
591 for (offset = 0; offset < aligned_length; offset += sizeof(u32)) {
592 data32 = *((u32 *)(data + offset));
593 if (is_master)
594 iowrite32be(data32, priv->mst->io + addr + offset);
595 else
596 iowrite32be(data32, priv->slv->io + addr + offset);
597 }
598 }
599
mlxbf_i2c_smbus_read_data(struct mlxbf_i2c_priv * priv,u8 * data,u8 length,u32 addr,bool is_master)600 static void mlxbf_i2c_smbus_read_data(struct mlxbf_i2c_priv *priv,
601 u8 *data, u8 length, u32 addr,
602 bool is_master)
603 {
604 u32 data32, mask;
605 u8 byte, offset;
606
607 mask = sizeof(u32) - 1;
608
609 /*
610 * Data bytes in the Master GW Data Descriptor are shifted left
611 * so the data starts at the MSB of the descriptor registers as
612 * set by the underlying hardware. Enable byte swapping while
613 * reading data bytes from the 32 * 32-bit HW Data registers
614 * a.k.a Master GW Data Descriptor.
615 */
616
617 for (offset = 0; offset < (length & ~mask); offset += sizeof(u32)) {
618 if (is_master)
619 data32 = ioread32be(priv->mst->io + addr + offset);
620 else
621 data32 = ioread32be(priv->slv->io + addr + offset);
622 *((u32 *)(data + offset)) = data32;
623 }
624
625 if (!(length & mask))
626 return;
627
628 if (is_master)
629 data32 = ioread32be(priv->mst->io + addr + offset);
630 else
631 data32 = ioread32be(priv->slv->io + addr + offset);
632
633 for (byte = 0; byte < (length & mask); byte++) {
634 data[offset + byte] = data32 & GENMASK(7, 0);
635 data32 = ror32(data32, MLXBF_I2C_SHIFT_8);
636 }
637 }
638
mlxbf_i2c_smbus_enable(struct mlxbf_i2c_priv * priv,u8 slave,u8 len,u8 block_en,u8 pec_en,bool read)639 static int mlxbf_i2c_smbus_enable(struct mlxbf_i2c_priv *priv, u8 slave,
640 u8 len, u8 block_en, u8 pec_en, bool read)
641 {
642 u32 command;
643
644 /* Set Master GW control word. */
645 if (read) {
646 command = MLXBF_I2C_MASTER_ENABLE_READ;
647 command |= rol32(len, MLXBF_I2C_MASTER_READ_SHIFT);
648 } else {
649 command = MLXBF_I2C_MASTER_ENABLE_WRITE;
650 command |= rol32(len, MLXBF_I2C_MASTER_WRITE_SHIFT);
651 }
652 command |= rol32(slave, MLXBF_I2C_MASTER_SLV_ADDR_SHIFT);
653 command |= rol32(block_en, MLXBF_I2C_MASTER_PARSE_EXP_SHIFT);
654 command |= rol32(pec_en, MLXBF_I2C_MASTER_SEND_PEC_SHIFT);
655
656 /* Clear status bits. */
657 writel(0x0, priv->mst->io + MLXBF_I2C_SMBUS_MASTER_STATUS);
658 /* Set the cause data. */
659 writel(~0x0, priv->mst_cause->io + MLXBF_I2C_CAUSE_OR_CLEAR);
660 /* Zero PEC byte. */
661 writel(0x0, priv->mst->io + MLXBF_I2C_SMBUS_MASTER_PEC);
662 /* Zero byte count. */
663 writel(0x0, priv->mst->io + priv->chip->smbus_master_rs_bytes_off);
664
665 /* GW activation. */
666 writel(command, priv->mst->io + MLXBF_I2C_SMBUS_MASTER_GW);
667
668 /*
669 * Poll master status and check status bits. An ACK is sent when
670 * completing writing data to the bus (Master 'byte_count_done' bit
671 * is set to 1).
672 */
673 return mlxbf_i2c_smbus_check_status(priv);
674 }
675
676 static int
mlxbf_i2c_smbus_start_transaction(struct mlxbf_i2c_priv * priv,struct mlxbf_i2c_smbus_request * request)677 mlxbf_i2c_smbus_start_transaction(struct mlxbf_i2c_priv *priv,
678 struct mlxbf_i2c_smbus_request *request)
679 {
680 u8 data_desc[MLXBF_I2C_MASTER_DATA_DESC_SIZE] = { 0 };
681 u8 op_idx, data_idx, data_len, write_len, read_len;
682 struct mlxbf_i2c_smbus_operation *operation;
683 u8 read_en, write_en, block_en, pec_en;
684 u8 slave, flags, addr;
685 u8 *read_buf;
686 u32 bits;
687 int ret;
688
689 if (request->operation_cnt > MLXBF_I2C_SMBUS_MAX_OP_CNT)
690 return -EINVAL;
691
692 read_buf = NULL;
693 data_idx = 0;
694 read_en = 0;
695 write_en = 0;
696 write_len = 0;
697 read_len = 0;
698 block_en = 0;
699 pec_en = 0;
700 slave = request->slave & GENMASK(6, 0);
701 addr = slave << 1;
702
703 /*
704 * Try to acquire the smbus gw lock before any reads of the GW register since
705 * a read sets the lock.
706 */
707 ret = readl_poll_timeout_atomic(priv->mst->io + MLXBF_I2C_SMBUS_MASTER_GW,
708 bits, !(bits & MLXBF_I2C_MASTER_LOCK_BIT),
709 MLXBF_I2C_POLL_FREQ_IN_USEC,
710 MLXBF_I2C_SMBUS_LOCK_POLL_TIMEOUT);
711 if (WARN_ON(ret))
712 return -EBUSY;
713
714 /*
715 * SW must make sure that the SMBus Master GW is idle before starting
716 * a transaction. Accordingly, this call polls the Master FSM stop bit;
717 * it returns -ETIMEDOUT when the bit is asserted, 0 if not.
718 */
719 ret = readl_poll_timeout_atomic(priv->mst->io + priv->chip->smbus_master_fsm_off,
720 bits, !(bits & MLXBF_I2C_SMBUS_MASTER_FSM_STOP_MASK),
721 MLXBF_I2C_POLL_FREQ_IN_USEC, MLXBF_I2C_SMBUS_TIMEOUT);
722 if (WARN_ON(ret)) {
723 ret = -EBUSY;
724 goto out_unlock;
725 }
726
727 /* Set first byte. */
728 data_desc[data_idx++] = addr;
729
730 for (op_idx = 0; op_idx < request->operation_cnt; op_idx++) {
731 operation = &request->operation[op_idx];
732 flags = operation->flags;
733
734 /*
735 * Note that read and write operations might be handled by a
736 * single command. If the MLXBF_I2C_F_SMBUS_OPERATION is set
737 * then write command byte and set the optional SMBus specific
738 * bits such as block_en and pec_en. These bits MUST be
739 * submitted by the first operation only.
740 */
741 if (op_idx == 0 && flags & MLXBF_I2C_F_SMBUS_OPERATION) {
742 block_en = flags & MLXBF_I2C_F_SMBUS_BLOCK;
743 pec_en = flags & MLXBF_I2C_F_SMBUS_PEC;
744 }
745
746 if (flags & MLXBF_I2C_F_WRITE) {
747 write_en = 1;
748 write_len += operation->length;
749 if (data_idx + operation->length >
750 MLXBF_I2C_MASTER_DATA_DESC_SIZE) {
751 ret = -ENOBUFS;
752 goto out_unlock;
753 }
754 memcpy(data_desc + data_idx,
755 operation->buffer, operation->length);
756 data_idx += operation->length;
757 }
758 /*
759 * We assume that read operations are performed only once per
760 * SMBus transaction. *TBD* protect this statement so it won't
761 * be executed twice? or return an error if we try to read more
762 * than once?
763 */
764 if (flags & MLXBF_I2C_F_READ) {
765 read_en = 1;
766 /* Subtract 1 as required by HW. */
767 read_len = operation->length - 1;
768 read_buf = operation->buffer;
769 }
770 }
771
772 /* Set Master GW data descriptor. */
773 data_len = write_len + 1; /* Add one byte of the slave address. */
774 /*
775 * Note that data_len cannot be 0. Indeed, the slave address byte
776 * must be written to the data registers.
777 */
778 mlxbf_i2c_smbus_write_data(priv, (const u8 *)data_desc, data_len,
779 MLXBF_I2C_MASTER_DATA_DESC_ADDR, true);
780
781 if (write_en) {
782 ret = mlxbf_i2c_smbus_enable(priv, slave, write_len, block_en,
783 pec_en, 0);
784 if (ret)
785 goto out_unlock;
786 }
787
788 if (read_en) {
789 /* Write slave address to Master GW data descriptor. */
790 mlxbf_i2c_smbus_write_data(priv, (const u8 *)&addr, 1,
791 MLXBF_I2C_MASTER_DATA_DESC_ADDR, true);
792 ret = mlxbf_i2c_smbus_enable(priv, slave, read_len, block_en,
793 pec_en, 1);
794 if (!ret) {
795 /* Get Master GW data descriptor. */
796 mlxbf_i2c_smbus_read_data(priv, data_desc, read_len + 1,
797 MLXBF_I2C_MASTER_DATA_DESC_ADDR, true);
798
799 /* Get data from Master GW data descriptor. */
800 memcpy(read_buf, data_desc, read_len + 1);
801 }
802
803 /*
804 * After a read operation the SMBus FSM ps (present state)
805 * needs to be 'manually' reset. This should be removed in
806 * next tag integration.
807 */
808 writel(MLXBF_I2C_SMBUS_MASTER_FSM_PS_STATE_MASK,
809 priv->mst->io + priv->chip->smbus_master_fsm_off);
810 }
811
812 out_unlock:
813 /* Clear the gw to clear the lock */
814 writel(0, priv->mst->io + MLXBF_I2C_SMBUS_MASTER_GW);
815
816 return ret;
817 }
818
819 /* I2C SMBus protocols. */
820
821 static void
mlxbf_i2c_smbus_quick_command(struct mlxbf_i2c_smbus_request * request,u8 read)822 mlxbf_i2c_smbus_quick_command(struct mlxbf_i2c_smbus_request *request,
823 u8 read)
824 {
825 request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_1;
826
827 request->operation[0].length = 0;
828 request->operation[0].flags = MLXBF_I2C_F_WRITE;
829 request->operation[0].flags |= read ? MLXBF_I2C_F_READ : 0;
830 }
831
mlxbf_i2c_smbus_byte_func(struct mlxbf_i2c_smbus_request * request,u8 * data,bool read,bool pec_check)832 static void mlxbf_i2c_smbus_byte_func(struct mlxbf_i2c_smbus_request *request,
833 u8 *data, bool read, bool pec_check)
834 {
835 request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_1;
836
837 request->operation[0].length = 1;
838 request->operation[0].length += pec_check;
839
840 request->operation[0].flags = MLXBF_I2C_F_SMBUS_OPERATION;
841 request->operation[0].flags |= read ?
842 MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE;
843 request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
844
845 request->operation[0].buffer = data;
846 }
847
848 static void
mlxbf_i2c_smbus_data_byte_func(struct mlxbf_i2c_smbus_request * request,u8 * command,u8 * data,bool read,bool pec_check)849 mlxbf_i2c_smbus_data_byte_func(struct mlxbf_i2c_smbus_request *request,
850 u8 *command, u8 *data, bool read, bool pec_check)
851 {
852 request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_2;
853
854 request->operation[0].length = 1;
855 request->operation[0].flags =
856 MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
857 request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
858 request->operation[0].buffer = command;
859
860 request->operation[1].length = 1;
861 request->operation[1].length += pec_check;
862 request->operation[1].flags = read ?
863 MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE;
864 request->operation[1].buffer = data;
865 }
866
867 static void
mlxbf_i2c_smbus_data_word_func(struct mlxbf_i2c_smbus_request * request,u8 * command,u8 * data,bool read,bool pec_check)868 mlxbf_i2c_smbus_data_word_func(struct mlxbf_i2c_smbus_request *request,
869 u8 *command, u8 *data, bool read, bool pec_check)
870 {
871 request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_2;
872
873 request->operation[0].length = 1;
874 request->operation[0].flags =
875 MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
876 request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
877 request->operation[0].buffer = command;
878
879 request->operation[1].length = 2;
880 request->operation[1].length += pec_check;
881 request->operation[1].flags = read ?
882 MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE;
883 request->operation[1].buffer = data;
884 }
885
886 static void
mlxbf_i2c_smbus_i2c_block_func(struct mlxbf_i2c_smbus_request * request,u8 * command,u8 * data,u8 * data_len,bool read,bool pec_check)887 mlxbf_i2c_smbus_i2c_block_func(struct mlxbf_i2c_smbus_request *request,
888 u8 *command, u8 *data, u8 *data_len, bool read,
889 bool pec_check)
890 {
891 request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_2;
892
893 request->operation[0].length = 1;
894 request->operation[0].flags =
895 MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
896 request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
897 request->operation[0].buffer = command;
898
899 /*
900 * As specified in the standard, the max number of bytes to read/write
901 * per block operation is 32 bytes. In Golan code, the controller can
902 * read up to 128 bytes and write up to 127 bytes.
903 */
904 request->operation[1].length =
905 (*data_len + pec_check > I2C_SMBUS_BLOCK_MAX) ?
906 I2C_SMBUS_BLOCK_MAX : *data_len + pec_check;
907 request->operation[1].flags = read ?
908 MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE;
909 /*
910 * Skip the first data byte, which corresponds to the number of bytes
911 * to read/write.
912 */
913 request->operation[1].buffer = data + 1;
914
915 *data_len = request->operation[1].length;
916
917 /* Set the number of byte to read. This will be used by userspace. */
918 if (read)
919 data[0] = *data_len;
920 }
921
mlxbf_i2c_smbus_block_func(struct mlxbf_i2c_smbus_request * request,u8 * command,u8 * data,u8 * data_len,bool read,bool pec_check)922 static void mlxbf_i2c_smbus_block_func(struct mlxbf_i2c_smbus_request *request,
923 u8 *command, u8 *data, u8 *data_len,
924 bool read, bool pec_check)
925 {
926 request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_2;
927
928 request->operation[0].length = 1;
929 request->operation[0].flags =
930 MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
931 request->operation[0].flags |= MLXBF_I2C_F_SMBUS_BLOCK;
932 request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
933 request->operation[0].buffer = command;
934
935 request->operation[1].length =
936 (*data_len + pec_check > I2C_SMBUS_BLOCK_MAX) ?
937 I2C_SMBUS_BLOCK_MAX : *data_len + pec_check;
938 request->operation[1].flags = read ?
939 MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE;
940 request->operation[1].buffer = data + 1;
941
942 *data_len = request->operation[1].length;
943
944 /* Set the number of bytes to read. This will be used by userspace. */
945 if (read)
946 data[0] = *data_len;
947 }
948
949 static void
mlxbf_i2c_smbus_process_call_func(struct mlxbf_i2c_smbus_request * request,u8 * command,u8 * data,bool pec_check)950 mlxbf_i2c_smbus_process_call_func(struct mlxbf_i2c_smbus_request *request,
951 u8 *command, u8 *data, bool pec_check)
952 {
953 request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_3;
954
955 request->operation[0].length = 1;
956 request->operation[0].flags =
957 MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
958 request->operation[0].flags |= MLXBF_I2C_F_SMBUS_BLOCK;
959 request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
960 request->operation[0].buffer = command;
961
962 request->operation[1].length = 2;
963 request->operation[1].flags = MLXBF_I2C_F_WRITE;
964 request->operation[1].buffer = data;
965
966 request->operation[2].length = 3;
967 request->operation[2].flags = MLXBF_I2C_F_READ;
968 request->operation[2].buffer = data;
969 }
970
971 static void
mlxbf_i2c_smbus_blk_process_call_func(struct mlxbf_i2c_smbus_request * request,u8 * command,u8 * data,u8 * data_len,bool pec_check)972 mlxbf_i2c_smbus_blk_process_call_func(struct mlxbf_i2c_smbus_request *request,
973 u8 *command, u8 *data, u8 *data_len,
974 bool pec_check)
975 {
976 u32 length;
977
978 request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_3;
979
980 request->operation[0].length = 1;
981 request->operation[0].flags =
982 MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
983 request->operation[0].flags |= MLXBF_I2C_F_SMBUS_BLOCK;
984 request->operation[0].flags |= (pec_check) ? MLXBF_I2C_F_SMBUS_PEC : 0;
985 request->operation[0].buffer = command;
986
987 length = (*data_len + pec_check > I2C_SMBUS_BLOCK_MAX) ?
988 I2C_SMBUS_BLOCK_MAX : *data_len + pec_check;
989
990 request->operation[1].length = length - pec_check;
991 request->operation[1].flags = MLXBF_I2C_F_WRITE;
992 request->operation[1].buffer = data;
993
994 request->operation[2].length = length;
995 request->operation[2].flags = MLXBF_I2C_F_READ;
996 request->operation[2].buffer = data;
997
998 *data_len = length; /* including PEC byte. */
999 }
1000
1001 /* Initialization functions. */
1002
mlxbf_i2c_has_chip_type(struct mlxbf_i2c_priv * priv,u8 type)1003 static bool mlxbf_i2c_has_chip_type(struct mlxbf_i2c_priv *priv, u8 type)
1004 {
1005 return priv->chip->type == type;
1006 }
1007
1008 static struct mlxbf_i2c_resource *
mlxbf_i2c_get_shared_resource(struct mlxbf_i2c_priv * priv,u8 type)1009 mlxbf_i2c_get_shared_resource(struct mlxbf_i2c_priv *priv, u8 type)
1010 {
1011 const struct mlxbf_i2c_chip_info *chip = priv->chip;
1012 struct mlxbf_i2c_resource *res;
1013 u8 res_idx = 0;
1014
1015 for (res_idx = 0; res_idx < MLXBF_I2C_SHARED_RES_MAX; res_idx++) {
1016 res = chip->shared_res[res_idx];
1017 if (res && res->type == type)
1018 return res;
1019 }
1020
1021 return NULL;
1022 }
1023
mlxbf_i2c_init_resource(struct platform_device * pdev,struct mlxbf_i2c_resource ** res,u8 type)1024 static int mlxbf_i2c_init_resource(struct platform_device *pdev,
1025 struct mlxbf_i2c_resource **res,
1026 u8 type)
1027 {
1028 struct mlxbf_i2c_resource *tmp_res;
1029 struct device *dev = &pdev->dev;
1030
1031 if (!res || *res || type >= MLXBF_I2C_END_RES)
1032 return -EINVAL;
1033
1034 tmp_res = devm_kzalloc(dev, sizeof(struct mlxbf_i2c_resource),
1035 GFP_KERNEL);
1036 if (!tmp_res)
1037 return -ENOMEM;
1038
1039 tmp_res->io = devm_platform_get_and_ioremap_resource(pdev, type, &tmp_res->params);
1040 if (IS_ERR(tmp_res->io)) {
1041 devm_kfree(dev, tmp_res);
1042 return PTR_ERR(tmp_res->io);
1043 }
1044
1045 tmp_res->type = type;
1046
1047 *res = tmp_res;
1048
1049 return 0;
1050 }
1051
mlxbf_i2c_get_ticks(struct mlxbf_i2c_priv * priv,u64 nanoseconds,bool minimum)1052 static u32 mlxbf_i2c_get_ticks(struct mlxbf_i2c_priv *priv, u64 nanoseconds,
1053 bool minimum)
1054 {
1055 u64 frequency;
1056 u32 ticks;
1057
1058 /*
1059 * Compute ticks as follow:
1060 *
1061 * Ticks
1062 * Time = --------- x 10^9 => Ticks = Time x Frequency x 10^-9
1063 * Frequency
1064 */
1065 frequency = priv->frequency;
1066 ticks = (nanoseconds * frequency) / MLXBF_I2C_FREQUENCY_1GHZ;
1067 /*
1068 * The number of ticks is rounded down and if minimum is equal to 1
1069 * then add one tick.
1070 */
1071 if (minimum)
1072 ticks++;
1073
1074 return ticks;
1075 }
1076
mlxbf_i2c_set_timer(struct mlxbf_i2c_priv * priv,u64 nsec,bool opt,u32 mask,u8 shift)1077 static u32 mlxbf_i2c_set_timer(struct mlxbf_i2c_priv *priv, u64 nsec, bool opt,
1078 u32 mask, u8 shift)
1079 {
1080 u32 val = (mlxbf_i2c_get_ticks(priv, nsec, opt) & mask) << shift;
1081
1082 return val;
1083 }
1084
mlxbf_i2c_set_timings(struct mlxbf_i2c_priv * priv,const struct mlxbf_i2c_timings * timings)1085 static void mlxbf_i2c_set_timings(struct mlxbf_i2c_priv *priv,
1086 const struct mlxbf_i2c_timings *timings)
1087 {
1088 u32 timer;
1089
1090 timer = mlxbf_i2c_set_timer(priv, timings->scl_high,
1091 false, MLXBF_I2C_MASK_16,
1092 MLXBF_I2C_SHIFT_0);
1093 timer |= mlxbf_i2c_set_timer(priv, timings->scl_low,
1094 false, MLXBF_I2C_MASK_16,
1095 MLXBF_I2C_SHIFT_16);
1096 writel(timer, priv->timer->io +
1097 MLXBF_I2C_SMBUS_TIMER_SCL_LOW_SCL_HIGH);
1098
1099 timer = mlxbf_i2c_set_timer(priv, timings->sda_rise, false,
1100 MLXBF_I2C_MASK_8, MLXBF_I2C_SHIFT_0);
1101 timer |= mlxbf_i2c_set_timer(priv, timings->sda_fall, false,
1102 MLXBF_I2C_MASK_8, MLXBF_I2C_SHIFT_8);
1103 timer |= mlxbf_i2c_set_timer(priv, timings->scl_rise, false,
1104 MLXBF_I2C_MASK_8, MLXBF_I2C_SHIFT_16);
1105 timer |= mlxbf_i2c_set_timer(priv, timings->scl_fall, false,
1106 MLXBF_I2C_MASK_8, MLXBF_I2C_SHIFT_24);
1107 writel(timer, priv->timer->io +
1108 MLXBF_I2C_SMBUS_TIMER_FALL_RISE_SPIKE);
1109
1110 timer = mlxbf_i2c_set_timer(priv, timings->hold_start, true,
1111 MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_0);
1112 timer |= mlxbf_i2c_set_timer(priv, timings->hold_data, true,
1113 MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_16);
1114 writel(timer, priv->timer->io + MLXBF_I2C_SMBUS_TIMER_THOLD);
1115
1116 timer = mlxbf_i2c_set_timer(priv, timings->setup_start, true,
1117 MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_0);
1118 timer |= mlxbf_i2c_set_timer(priv, timings->setup_stop, true,
1119 MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_16);
1120 writel(timer, priv->timer->io +
1121 MLXBF_I2C_SMBUS_TIMER_TSETUP_START_STOP);
1122
1123 timer = mlxbf_i2c_set_timer(priv, timings->setup_data, true,
1124 MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_0);
1125 writel(timer, priv->timer->io + MLXBF_I2C_SMBUS_TIMER_TSETUP_DATA);
1126
1127 timer = mlxbf_i2c_set_timer(priv, timings->buf, false,
1128 MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_0);
1129 timer |= mlxbf_i2c_set_timer(priv, timings->thigh_max, false,
1130 MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_16);
1131 writel(timer, priv->timer->io + MLXBF_I2C_SMBUS_THIGH_MAX_TBUF);
1132
1133 timer = timings->timeout;
1134 writel(timer, priv->timer->io + MLXBF_I2C_SMBUS_SCL_LOW_TIMEOUT);
1135 }
1136
1137 enum mlxbf_i2c_timings_config {
1138 MLXBF_I2C_TIMING_CONFIG_100KHZ,
1139 MLXBF_I2C_TIMING_CONFIG_400KHZ,
1140 MLXBF_I2C_TIMING_CONFIG_1000KHZ,
1141 };
1142
1143 /*
1144 * Note that the mlxbf_i2c_timings->timeout value is not related to the
1145 * bus frequency, it is impacted by the time it takes the driver to
1146 * complete data transmission before transaction abort.
1147 */
1148 static const struct mlxbf_i2c_timings mlxbf_i2c_timings[] = {
1149 [MLXBF_I2C_TIMING_CONFIG_100KHZ] = {
1150 .scl_high = 4810,
1151 .scl_low = 5000,
1152 .hold_start = 4000,
1153 .setup_start = 4800,
1154 .setup_stop = 4000,
1155 .setup_data = 250,
1156 .sda_rise = 50,
1157 .sda_fall = 50,
1158 .scl_rise = 50,
1159 .scl_fall = 50,
1160 .hold_data = 300,
1161 .buf = 20000,
1162 .thigh_max = 5000,
1163 .timeout = 106500
1164 },
1165 [MLXBF_I2C_TIMING_CONFIG_400KHZ] = {
1166 .scl_high = 1011,
1167 .scl_low = 1300,
1168 .hold_start = 600,
1169 .setup_start = 700,
1170 .setup_stop = 600,
1171 .setup_data = 100,
1172 .sda_rise = 50,
1173 .sda_fall = 50,
1174 .scl_rise = 50,
1175 .scl_fall = 50,
1176 .hold_data = 300,
1177 .buf = 20000,
1178 .thigh_max = 5000,
1179 .timeout = 106500
1180 },
1181 [MLXBF_I2C_TIMING_CONFIG_1000KHZ] = {
1182 .scl_high = 600,
1183 .scl_low = 1300,
1184 .hold_start = 600,
1185 .setup_start = 600,
1186 .setup_stop = 600,
1187 .setup_data = 100,
1188 .sda_rise = 50,
1189 .sda_fall = 50,
1190 .scl_rise = 50,
1191 .scl_fall = 50,
1192 .hold_data = 300,
1193 .buf = 20000,
1194 .thigh_max = 5000,
1195 .timeout = 106500
1196 }
1197 };
1198
mlxbf_i2c_init_timings(struct platform_device * pdev,struct mlxbf_i2c_priv * priv)1199 static int mlxbf_i2c_init_timings(struct platform_device *pdev,
1200 struct mlxbf_i2c_priv *priv)
1201 {
1202 enum mlxbf_i2c_timings_config config_idx;
1203 struct device *dev = &pdev->dev;
1204 u32 config_khz;
1205
1206 int ret;
1207
1208 ret = device_property_read_u32(dev, "clock-frequency", &config_khz);
1209 if (ret < 0)
1210 config_khz = I2C_MAX_STANDARD_MODE_FREQ;
1211
1212 switch (config_khz) {
1213 default:
1214 /* Default settings is 100 KHz. */
1215 pr_warn("Illegal value %d: defaulting to 100 KHz\n",
1216 config_khz);
1217 fallthrough;
1218 case I2C_MAX_STANDARD_MODE_FREQ:
1219 config_idx = MLXBF_I2C_TIMING_CONFIG_100KHZ;
1220 break;
1221
1222 case I2C_MAX_FAST_MODE_FREQ:
1223 config_idx = MLXBF_I2C_TIMING_CONFIG_400KHZ;
1224 break;
1225
1226 case I2C_MAX_FAST_MODE_PLUS_FREQ:
1227 config_idx = MLXBF_I2C_TIMING_CONFIG_1000KHZ;
1228 break;
1229 }
1230
1231 mlxbf_i2c_set_timings(priv, &mlxbf_i2c_timings[config_idx]);
1232
1233 return 0;
1234 }
1235
mlxbf_i2c_get_gpio(struct platform_device * pdev,struct mlxbf_i2c_priv * priv)1236 static int mlxbf_i2c_get_gpio(struct platform_device *pdev,
1237 struct mlxbf_i2c_priv *priv)
1238 {
1239 struct mlxbf_i2c_resource *gpio_res;
1240 struct device *dev = &pdev->dev;
1241 struct resource *params;
1242 resource_size_t size;
1243
1244 gpio_res = mlxbf_i2c_get_shared_resource(priv, MLXBF_I2C_GPIO_RES);
1245 if (!gpio_res)
1246 return -EPERM;
1247
1248 /*
1249 * The GPIO region in TYU space is shared among I2C busses.
1250 * This function MUST be serialized to avoid racing when
1251 * claiming the memory region and/or setting up the GPIO.
1252 */
1253 lockdep_assert_held(gpio_res->lock);
1254
1255 /* Check whether the memory map exist. */
1256 if (gpio_res->io)
1257 return 0;
1258
1259 params = gpio_res->params;
1260 size = resource_size(params);
1261
1262 if (!devm_request_mem_region(dev, params->start, size, params->name))
1263 return -EFAULT;
1264
1265 gpio_res->io = devm_ioremap(dev, params->start, size);
1266 if (!gpio_res->io) {
1267 devm_release_mem_region(dev, params->start, size);
1268 return -ENOMEM;
1269 }
1270
1271 return 0;
1272 }
1273
mlxbf_i2c_release_gpio(struct platform_device * pdev,struct mlxbf_i2c_priv * priv)1274 static int mlxbf_i2c_release_gpio(struct platform_device *pdev,
1275 struct mlxbf_i2c_priv *priv)
1276 {
1277 struct mlxbf_i2c_resource *gpio_res;
1278 struct device *dev = &pdev->dev;
1279 struct resource *params;
1280
1281 gpio_res = mlxbf_i2c_get_shared_resource(priv, MLXBF_I2C_GPIO_RES);
1282 if (!gpio_res)
1283 return 0;
1284
1285 mutex_lock(gpio_res->lock);
1286
1287 if (gpio_res->io) {
1288 /* Release the GPIO resource. */
1289 params = gpio_res->params;
1290 devm_iounmap(dev, gpio_res->io);
1291 devm_release_mem_region(dev, params->start,
1292 resource_size(params));
1293 }
1294
1295 mutex_unlock(gpio_res->lock);
1296
1297 return 0;
1298 }
1299
mlxbf_i2c_get_corepll(struct platform_device * pdev,struct mlxbf_i2c_priv * priv)1300 static int mlxbf_i2c_get_corepll(struct platform_device *pdev,
1301 struct mlxbf_i2c_priv *priv)
1302 {
1303 struct mlxbf_i2c_resource *corepll_res;
1304 struct device *dev = &pdev->dev;
1305 struct resource *params;
1306 resource_size_t size;
1307
1308 corepll_res = mlxbf_i2c_get_shared_resource(priv,
1309 MLXBF_I2C_COREPLL_RES);
1310 if (!corepll_res)
1311 return -EPERM;
1312
1313 /*
1314 * The COREPLL region in TYU space is shared among I2C busses.
1315 * This function MUST be serialized to avoid racing when
1316 * claiming the memory region.
1317 */
1318 lockdep_assert_held(corepll_res->lock);
1319
1320 /* Check whether the memory map exist. */
1321 if (corepll_res->io)
1322 return 0;
1323
1324 params = corepll_res->params;
1325 size = resource_size(params);
1326
1327 if (!devm_request_mem_region(dev, params->start, size, params->name))
1328 return -EFAULT;
1329
1330 corepll_res->io = devm_ioremap(dev, params->start, size);
1331 if (!corepll_res->io) {
1332 devm_release_mem_region(dev, params->start, size);
1333 return -ENOMEM;
1334 }
1335
1336 return 0;
1337 }
1338
mlxbf_i2c_release_corepll(struct platform_device * pdev,struct mlxbf_i2c_priv * priv)1339 static int mlxbf_i2c_release_corepll(struct platform_device *pdev,
1340 struct mlxbf_i2c_priv *priv)
1341 {
1342 struct mlxbf_i2c_resource *corepll_res;
1343 struct device *dev = &pdev->dev;
1344 struct resource *params;
1345
1346 corepll_res = mlxbf_i2c_get_shared_resource(priv,
1347 MLXBF_I2C_COREPLL_RES);
1348
1349 mutex_lock(corepll_res->lock);
1350
1351 if (corepll_res->io) {
1352 /* Release the CorePLL resource. */
1353 params = corepll_res->params;
1354 devm_iounmap(dev, corepll_res->io);
1355 devm_release_mem_region(dev, params->start,
1356 resource_size(params));
1357 }
1358
1359 mutex_unlock(corepll_res->lock);
1360
1361 return 0;
1362 }
1363
mlxbf_i2c_init_master(struct platform_device * pdev,struct mlxbf_i2c_priv * priv)1364 static int mlxbf_i2c_init_master(struct platform_device *pdev,
1365 struct mlxbf_i2c_priv *priv)
1366 {
1367 struct mlxbf_i2c_resource *gpio_res;
1368 struct device *dev = &pdev->dev;
1369 u32 config_reg;
1370 int ret;
1371
1372 /* This configuration is only needed for BlueField 1. */
1373 if (!mlxbf_i2c_has_chip_type(priv, MLXBF_I2C_CHIP_TYPE_1))
1374 return 0;
1375
1376 gpio_res = mlxbf_i2c_get_shared_resource(priv, MLXBF_I2C_GPIO_RES);
1377 if (!gpio_res)
1378 return -EPERM;
1379
1380 /*
1381 * The GPIO region in TYU space is shared among I2C busses.
1382 * This function MUST be serialized to avoid racing when
1383 * claiming the memory region and/or setting up the GPIO.
1384 */
1385
1386 mutex_lock(gpio_res->lock);
1387
1388 ret = mlxbf_i2c_get_gpio(pdev, priv);
1389 if (ret < 0) {
1390 dev_err(dev, "Failed to get gpio resource");
1391 mutex_unlock(gpio_res->lock);
1392 return ret;
1393 }
1394
1395 /*
1396 * TYU - Configuration for GPIO pins. Those pins must be asserted in
1397 * MLXBF_I2C_GPIO_0_FUNC_EN_0, i.e. GPIO 0 is controlled by HW, and must
1398 * be reset in MLXBF_I2C_GPIO_0_FORCE_OE_EN, i.e. GPIO_OE will be driven
1399 * instead of HW_OE.
1400 * For now, we do not reset the GPIO state when the driver is removed.
1401 * First, it is not necessary to disable the bus since we are using
1402 * the same busses. Then, some busses might be shared among Linux and
1403 * platform firmware; disabling the bus might compromise the system
1404 * functionality.
1405 */
1406 config_reg = readl(gpio_res->io + MLXBF_I2C_GPIO_0_FUNC_EN_0);
1407 config_reg = MLXBF_I2C_GPIO_SMBUS_GW_ASSERT_PINS(priv->bus,
1408 config_reg);
1409 writel(config_reg, gpio_res->io + MLXBF_I2C_GPIO_0_FUNC_EN_0);
1410
1411 config_reg = readl(gpio_res->io + MLXBF_I2C_GPIO_0_FORCE_OE_EN);
1412 config_reg = MLXBF_I2C_GPIO_SMBUS_GW_RESET_PINS(priv->bus,
1413 config_reg);
1414 writel(config_reg, gpio_res->io + MLXBF_I2C_GPIO_0_FORCE_OE_EN);
1415
1416 mutex_unlock(gpio_res->lock);
1417
1418 return 0;
1419 }
1420
mlxbf_i2c_calculate_freq_from_tyu(struct mlxbf_i2c_resource * corepll_res)1421 static u64 mlxbf_i2c_calculate_freq_from_tyu(struct mlxbf_i2c_resource *corepll_res)
1422 {
1423 u64 core_frequency;
1424 u8 core_od, core_r;
1425 u32 corepll_val;
1426 u16 core_f;
1427
1428 corepll_val = readl(corepll_res->io + MLXBF_I2C_CORE_PLL_REG1);
1429
1430 /* Get Core PLL configuration bits. */
1431 core_f = FIELD_GET(MLXBF_I2C_COREPLL_CORE_F_TYU_MASK, corepll_val);
1432 core_od = FIELD_GET(MLXBF_I2C_COREPLL_CORE_OD_TYU_MASK, corepll_val);
1433 core_r = FIELD_GET(MLXBF_I2C_COREPLL_CORE_R_TYU_MASK, corepll_val);
1434
1435 /*
1436 * Compute PLL output frequency as follow:
1437 *
1438 * CORE_F + 1
1439 * PLL_OUT_FREQ = PLL_IN_FREQ * ----------------------------
1440 * (CORE_R + 1) * (CORE_OD + 1)
1441 *
1442 * Where PLL_OUT_FREQ and PLL_IN_FREQ refer to CoreFrequency
1443 * and PadFrequency, respectively.
1444 */
1445 core_frequency = MLXBF_I2C_PLL_IN_FREQ * (++core_f);
1446 core_frequency /= (++core_r) * (++core_od);
1447
1448 return core_frequency;
1449 }
1450
mlxbf_i2c_calculate_freq_from_yu(struct mlxbf_i2c_resource * corepll_res)1451 static u64 mlxbf_i2c_calculate_freq_from_yu(struct mlxbf_i2c_resource *corepll_res)
1452 {
1453 u32 corepll_reg1_val, corepll_reg2_val;
1454 u64 corepll_frequency;
1455 u8 core_od, core_r;
1456 u32 core_f;
1457
1458 corepll_reg1_val = readl(corepll_res->io + MLXBF_I2C_CORE_PLL_REG1);
1459 corepll_reg2_val = readl(corepll_res->io + MLXBF_I2C_CORE_PLL_REG2);
1460
1461 /* Get Core PLL configuration bits */
1462 core_f = FIELD_GET(MLXBF_I2C_COREPLL_CORE_F_YU_MASK, corepll_reg1_val);
1463 core_r = FIELD_GET(MLXBF_I2C_COREPLL_CORE_R_YU_MASK, corepll_reg1_val);
1464 core_od = FIELD_GET(MLXBF_I2C_COREPLL_CORE_OD_YU_MASK, corepll_reg2_val);
1465
1466 /*
1467 * Compute PLL output frequency as follow:
1468 *
1469 * CORE_F / 16384
1470 * PLL_OUT_FREQ = PLL_IN_FREQ * ----------------------------
1471 * (CORE_R + 1) * (CORE_OD + 1)
1472 *
1473 * Where PLL_OUT_FREQ and PLL_IN_FREQ refer to CoreFrequency
1474 * and PadFrequency, respectively.
1475 */
1476 corepll_frequency = (MLXBF_I2C_PLL_IN_FREQ * core_f) / MLNXBF_I2C_COREPLL_CONST;
1477 corepll_frequency /= (++core_r) * (++core_od);
1478
1479 return corepll_frequency;
1480 }
1481
mlxbf_i2c_calculate_corepll_freq(struct platform_device * pdev,struct mlxbf_i2c_priv * priv)1482 static int mlxbf_i2c_calculate_corepll_freq(struct platform_device *pdev,
1483 struct mlxbf_i2c_priv *priv)
1484 {
1485 const struct mlxbf_i2c_chip_info *chip = priv->chip;
1486 struct mlxbf_i2c_resource *corepll_res;
1487 struct device *dev = &pdev->dev;
1488 u64 *freq = &priv->frequency;
1489 int ret;
1490
1491 corepll_res = mlxbf_i2c_get_shared_resource(priv,
1492 MLXBF_I2C_COREPLL_RES);
1493 if (!corepll_res)
1494 return -EPERM;
1495
1496 /*
1497 * First, check whether the TYU core Clock frequency is set.
1498 * The TYU core frequency is the same for all I2C busses; when
1499 * the first device gets probed the frequency is determined and
1500 * stored into a globally visible variable. So, first of all,
1501 * check whether the frequency is already set. Here, we assume
1502 * that the frequency is expected to be greater than 0.
1503 */
1504 mutex_lock(corepll_res->lock);
1505 if (!mlxbf_i2c_corepll_frequency) {
1506 if (!chip->calculate_freq) {
1507 mutex_unlock(corepll_res->lock);
1508 return -EPERM;
1509 }
1510
1511 ret = mlxbf_i2c_get_corepll(pdev, priv);
1512 if (ret < 0) {
1513 dev_err(dev, "Failed to get corePLL resource");
1514 mutex_unlock(corepll_res->lock);
1515 return ret;
1516 }
1517
1518 mlxbf_i2c_corepll_frequency = chip->calculate_freq(corepll_res);
1519 }
1520 mutex_unlock(corepll_res->lock);
1521
1522 *freq = mlxbf_i2c_corepll_frequency;
1523
1524 return 0;
1525 }
1526
mlxbf_i2c_slave_enable(struct mlxbf_i2c_priv * priv,struct i2c_client * slave)1527 static int mlxbf_i2c_slave_enable(struct mlxbf_i2c_priv *priv,
1528 struct i2c_client *slave)
1529 {
1530 u8 reg, reg_cnt, byte, addr_tmp;
1531 u32 slave_reg, slave_reg_tmp;
1532
1533 if (!priv)
1534 return -EPERM;
1535
1536 reg_cnt = MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT >> 2;
1537
1538 /*
1539 * Read the slave registers. There are 4 * 32-bit slave registers.
1540 * Each slave register can hold up to 4 * 8-bit slave configuration:
1541 * 1) A 7-bit address
1542 * 2) And a status bit (1 if enabled, 0 if not).
1543 * Look for the next available slave register slot.
1544 */
1545 for (reg = 0; reg < reg_cnt; reg++) {
1546 slave_reg = readl(priv->slv->io +
1547 MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG + reg * 0x4);
1548 /*
1549 * Each register holds 4 slave addresses. So, we have to keep
1550 * the byte order consistent with the value read in order to
1551 * update the register correctly, if needed.
1552 */
1553 slave_reg_tmp = slave_reg;
1554 for (byte = 0; byte < 4; byte++) {
1555 addr_tmp = slave_reg_tmp & GENMASK(7, 0);
1556
1557 /*
1558 * If an enable bit is not set in the
1559 * MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG register, then the
1560 * slave address slot associated with that bit is
1561 * free. So set the enable bit and write the
1562 * slave address bits.
1563 */
1564 if (!(addr_tmp & MLXBF_I2C_SMBUS_SLAVE_ADDR_EN_BIT)) {
1565 slave_reg &= ~(MLXBF_I2C_SMBUS_SLAVE_ADDR_MASK << (byte * 8));
1566 slave_reg |= (slave->addr << (byte * 8));
1567 slave_reg |= MLXBF_I2C_SMBUS_SLAVE_ADDR_EN_BIT << (byte * 8);
1568 writel(slave_reg, priv->slv->io +
1569 MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG +
1570 (reg * 0x4));
1571
1572 /*
1573 * Set the slave at the corresponding index.
1574 */
1575 priv->slave[(reg * 4) + byte] = slave;
1576
1577 return 0;
1578 }
1579
1580 /* Parse next byte. */
1581 slave_reg_tmp >>= 8;
1582 }
1583 }
1584
1585 return -EBUSY;
1586 }
1587
mlxbf_i2c_slave_disable(struct mlxbf_i2c_priv * priv,u8 addr)1588 static int mlxbf_i2c_slave_disable(struct mlxbf_i2c_priv *priv, u8 addr)
1589 {
1590 u8 addr_tmp, reg, reg_cnt, byte;
1591 u32 slave_reg, slave_reg_tmp;
1592
1593 reg_cnt = MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT >> 2;
1594
1595 /*
1596 * Read the slave registers. There are 4 * 32-bit slave registers.
1597 * Each slave register can hold up to 4 * 8-bit slave configuration:
1598 * 1) A 7-bit address
1599 * 2) And a status bit (1 if enabled, 0 if not).
1600 * Check if addr is present in the registers.
1601 */
1602 for (reg = 0; reg < reg_cnt; reg++) {
1603 slave_reg = readl(priv->slv->io +
1604 MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG + reg * 0x4);
1605
1606 /* Check whether the address slots are empty. */
1607 if (!slave_reg)
1608 continue;
1609
1610 /*
1611 * Check if addr matches any of the 4 slave addresses
1612 * in the register.
1613 */
1614 slave_reg_tmp = slave_reg;
1615 for (byte = 0; byte < 4; byte++) {
1616 addr_tmp = slave_reg_tmp & MLXBF_I2C_SMBUS_SLAVE_ADDR_MASK;
1617 /*
1618 * Parse slave address bytes and check whether the
1619 * slave address already exists.
1620 */
1621 if (addr_tmp == addr) {
1622 /* Clear the slave address slot. */
1623 slave_reg &= ~(GENMASK(7, 0) << (byte * 8));
1624 writel(slave_reg, priv->slv->io +
1625 MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG +
1626 (reg * 0x4));
1627 /* Free slave at the corresponding index */
1628 priv->slave[(reg * 4) + byte] = NULL;
1629
1630 return 0;
1631 }
1632
1633 /* Parse next byte. */
1634 slave_reg_tmp >>= 8;
1635 }
1636 }
1637
1638 return -ENXIO;
1639 }
1640
mlxbf_i2c_init_coalesce(struct platform_device * pdev,struct mlxbf_i2c_priv * priv)1641 static int mlxbf_i2c_init_coalesce(struct platform_device *pdev,
1642 struct mlxbf_i2c_priv *priv)
1643 {
1644 struct mlxbf_i2c_resource *coalesce_res;
1645 struct resource *params;
1646 resource_size_t size;
1647 int ret = 0;
1648
1649 /*
1650 * Unlike BlueField-1 platform, the coalesce registers is a dedicated
1651 * resource in the next generations of BlueField.
1652 */
1653 if (mlxbf_i2c_has_chip_type(priv, MLXBF_I2C_CHIP_TYPE_1)) {
1654 coalesce_res = mlxbf_i2c_get_shared_resource(priv,
1655 MLXBF_I2C_COALESCE_RES);
1656 if (!coalesce_res)
1657 return -EPERM;
1658
1659 /*
1660 * The Cause Coalesce group in TYU space is shared among
1661 * I2C busses. This function MUST be serialized to avoid
1662 * racing when claiming the memory region.
1663 */
1664 lockdep_assert_held(mlxbf_i2c_gpio_res->lock);
1665
1666 /* Check whether the memory map exist. */
1667 if (coalesce_res->io) {
1668 priv->coalesce = coalesce_res;
1669 return 0;
1670 }
1671
1672 params = coalesce_res->params;
1673 size = resource_size(params);
1674
1675 if (!request_mem_region(params->start, size, params->name))
1676 return -EFAULT;
1677
1678 coalesce_res->io = ioremap(params->start, size);
1679 if (!coalesce_res->io) {
1680 release_mem_region(params->start, size);
1681 return -ENOMEM;
1682 }
1683
1684 priv->coalesce = coalesce_res;
1685
1686 } else {
1687 ret = mlxbf_i2c_init_resource(pdev, &priv->coalesce,
1688 MLXBF_I2C_COALESCE_RES);
1689 }
1690
1691 return ret;
1692 }
1693
mlxbf_i2c_release_coalesce(struct platform_device * pdev,struct mlxbf_i2c_priv * priv)1694 static int mlxbf_i2c_release_coalesce(struct platform_device *pdev,
1695 struct mlxbf_i2c_priv *priv)
1696 {
1697 struct mlxbf_i2c_resource *coalesce_res;
1698 struct device *dev = &pdev->dev;
1699 struct resource *params;
1700 resource_size_t size;
1701
1702 coalesce_res = priv->coalesce;
1703
1704 if (coalesce_res->io) {
1705 params = coalesce_res->params;
1706 size = resource_size(params);
1707 if (mlxbf_i2c_has_chip_type(priv, MLXBF_I2C_CHIP_TYPE_1)) {
1708 mutex_lock(coalesce_res->lock);
1709 iounmap(coalesce_res->io);
1710 release_mem_region(params->start, size);
1711 mutex_unlock(coalesce_res->lock);
1712 } else {
1713 devm_release_mem_region(dev, params->start, size);
1714 }
1715 }
1716
1717 return 0;
1718 }
1719
mlxbf_i2c_init_slave(struct platform_device * pdev,struct mlxbf_i2c_priv * priv)1720 static int mlxbf_i2c_init_slave(struct platform_device *pdev,
1721 struct mlxbf_i2c_priv *priv)
1722 {
1723 struct device *dev = &pdev->dev;
1724 u32 int_reg;
1725 int ret;
1726
1727 /* Reset FSM. */
1728 writel(0, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_FSM);
1729
1730 /*
1731 * Enable slave cause interrupt bits. Drive
1732 * MLXBF_I2C_CAUSE_READ_WAIT_FW_RESPONSE and
1733 * MLXBF_I2C_CAUSE_WRITE_SUCCESS, these are enabled when an external
1734 * masters issue a Read and Write, respectively. But, clear all
1735 * interrupts first.
1736 */
1737 writel(~0, priv->slv_cause->io + MLXBF_I2C_CAUSE_OR_CLEAR);
1738 int_reg = MLXBF_I2C_CAUSE_READ_WAIT_FW_RESPONSE;
1739 int_reg |= MLXBF_I2C_CAUSE_WRITE_SUCCESS;
1740 writel(int_reg, priv->slv_cause->io + MLXBF_I2C_CAUSE_OR_EVTEN0);
1741
1742 /* Finally, set the 'ready' bit to start handling transactions. */
1743 writel(0x1, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_READY);
1744
1745 /* Initialize the cause coalesce resource. */
1746 ret = mlxbf_i2c_init_coalesce(pdev, priv);
1747 if (ret < 0) {
1748 dev_err(dev, "failed to initialize cause coalesce\n");
1749 return ret;
1750 }
1751
1752 return 0;
1753 }
1754
mlxbf_i2c_has_coalesce(struct mlxbf_i2c_priv * priv,bool * read,bool * write)1755 static bool mlxbf_i2c_has_coalesce(struct mlxbf_i2c_priv *priv, bool *read,
1756 bool *write)
1757 {
1758 const struct mlxbf_i2c_chip_info *chip = priv->chip;
1759 u32 coalesce0_reg, cause_reg;
1760 u8 slave_shift, is_set;
1761
1762 *write = false;
1763 *read = false;
1764
1765 slave_shift = chip->type != MLXBF_I2C_CHIP_TYPE_1 ?
1766 MLXBF_I2C_CAUSE_YU_SLAVE_BIT :
1767 priv->bus + MLXBF_I2C_CAUSE_TYU_SLAVE_BIT;
1768
1769 coalesce0_reg = readl(priv->coalesce->io + MLXBF_I2C_CAUSE_COALESCE_0);
1770 is_set = coalesce0_reg & (1 << slave_shift);
1771
1772 if (!is_set)
1773 return false;
1774
1775 /* Check the source of the interrupt, i.e. whether a Read or Write. */
1776 cause_reg = readl(priv->slv_cause->io + MLXBF_I2C_CAUSE_ARBITER);
1777 if (cause_reg & MLXBF_I2C_CAUSE_READ_WAIT_FW_RESPONSE)
1778 *read = true;
1779 else if (cause_reg & MLXBF_I2C_CAUSE_WRITE_SUCCESS)
1780 *write = true;
1781
1782 /* Clear cause bits. */
1783 writel(~0x0, priv->slv_cause->io + MLXBF_I2C_CAUSE_OR_CLEAR);
1784
1785 return true;
1786 }
1787
mlxbf_i2c_get_slave_from_addr(struct mlxbf_i2c_priv * priv,u8 addr)1788 static struct i2c_client *mlxbf_i2c_get_slave_from_addr(
1789 struct mlxbf_i2c_priv *priv, u8 addr)
1790 {
1791 int i;
1792
1793 for (i = 0; i < MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT; i++) {
1794 if (!priv->slave[i])
1795 continue;
1796
1797 if (priv->slave[i]->addr == addr)
1798 return priv->slave[i];
1799 }
1800
1801 return NULL;
1802 }
1803
1804 /*
1805 * Send byte to 'external' smbus master. This function is executed when
1806 * an external smbus master wants to read data from the BlueField.
1807 */
mlxbf_i2c_irq_send(struct mlxbf_i2c_priv * priv,u8 recv_bytes)1808 static int mlxbf_i2c_irq_send(struct mlxbf_i2c_priv *priv, u8 recv_bytes)
1809 {
1810 u8 data_desc[MLXBF_I2C_SLAVE_DATA_DESC_SIZE] = { 0 };
1811 u8 write_size, pec_en, addr, value, byte_cnt;
1812 struct i2c_client *slave;
1813 u32 control32, data32;
1814 int ret = 0;
1815
1816 /*
1817 * Read the first byte received from the external master to
1818 * determine the slave address. This byte is located in the
1819 * first data descriptor register of the slave GW.
1820 */
1821 data32 = ioread32be(priv->slv->io +
1822 MLXBF_I2C_SLAVE_DATA_DESC_ADDR);
1823 addr = (data32 & GENMASK(7, 0)) >> 1;
1824
1825 /*
1826 * Check if the slave address received in the data descriptor register
1827 * matches any of the slave addresses registered. If there is a match,
1828 * set the slave.
1829 */
1830 slave = mlxbf_i2c_get_slave_from_addr(priv, addr);
1831 if (!slave) {
1832 ret = -ENXIO;
1833 goto clear_csr;
1834 }
1835
1836 /*
1837 * An I2C read can consist of a WRITE bit transaction followed by
1838 * a READ bit transaction. Indeed, slave devices often expect
1839 * the slave address to be followed by the internal address.
1840 * So, write the internal address byte first, and then, send the
1841 * requested data to the master.
1842 */
1843 if (recv_bytes > 1) {
1844 i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value);
1845 value = (data32 >> 8) & GENMASK(7, 0);
1846 ret = i2c_slave_event(slave, I2C_SLAVE_WRITE_RECEIVED,
1847 &value);
1848 i2c_slave_event(slave, I2C_SLAVE_STOP, &value);
1849
1850 if (ret < 0)
1851 goto clear_csr;
1852 }
1853
1854 /*
1855 * Send data to the master. Currently, the driver supports
1856 * READ_BYTE, READ_WORD and BLOCK READ protocols. The
1857 * hardware can send up to 128 bytes per transfer which is
1858 * the total size of the data registers.
1859 */
1860 i2c_slave_event(slave, I2C_SLAVE_READ_REQUESTED, &value);
1861
1862 for (byte_cnt = 0; byte_cnt < MLXBF_I2C_SLAVE_DATA_DESC_SIZE; byte_cnt++) {
1863 data_desc[byte_cnt] = value;
1864 i2c_slave_event(slave, I2C_SLAVE_READ_PROCESSED, &value);
1865 }
1866
1867 /* Send a stop condition to the backend. */
1868 i2c_slave_event(slave, I2C_SLAVE_STOP, &value);
1869
1870 /* Set the number of bytes to write to master. */
1871 write_size = (byte_cnt - 1) & 0x7f;
1872
1873 /* Write data to Slave GW data descriptor. */
1874 mlxbf_i2c_smbus_write_data(priv, data_desc, byte_cnt,
1875 MLXBF_I2C_SLAVE_DATA_DESC_ADDR, false);
1876
1877 pec_en = 0; /* Disable PEC since it is not supported. */
1878
1879 /* Prepare control word. */
1880 control32 = MLXBF_I2C_SLAVE_ENABLE;
1881 control32 |= rol32(write_size, MLXBF_I2C_SLAVE_WRITE_BYTES_SHIFT);
1882 control32 |= rol32(pec_en, MLXBF_I2C_SLAVE_SEND_PEC_SHIFT);
1883
1884 writel(control32, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_GW);
1885
1886 /*
1887 * Wait until the transfer is completed; the driver will wait
1888 * until the GW is idle, a cause will rise on fall of GW busy.
1889 */
1890 readl_poll_timeout_atomic(priv->slv_cause->io + MLXBF_I2C_CAUSE_ARBITER,
1891 data32, data32 & MLXBF_I2C_CAUSE_S_GW_BUSY_FALL,
1892 MLXBF_I2C_POLL_FREQ_IN_USEC, MLXBF_I2C_SMBUS_TIMEOUT);
1893
1894 clear_csr:
1895 /* Release the Slave GW. */
1896 writel(0x0, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES);
1897 writel(0x0, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_PEC);
1898 writel(0x1, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_READY);
1899
1900 return ret;
1901 }
1902
1903 /*
1904 * Receive bytes from 'external' smbus master. This function is executed when
1905 * an external smbus master wants to write data to the BlueField.
1906 */
mlxbf_i2c_irq_recv(struct mlxbf_i2c_priv * priv,u8 recv_bytes)1907 static int mlxbf_i2c_irq_recv(struct mlxbf_i2c_priv *priv, u8 recv_bytes)
1908 {
1909 u8 data_desc[MLXBF_I2C_SLAVE_DATA_DESC_SIZE] = { 0 };
1910 struct i2c_client *slave;
1911 u8 value, byte, addr;
1912 int ret = 0;
1913
1914 /* Read data from Slave GW data descriptor. */
1915 mlxbf_i2c_smbus_read_data(priv, data_desc, recv_bytes,
1916 MLXBF_I2C_SLAVE_DATA_DESC_ADDR, false);
1917 addr = data_desc[0] >> 1;
1918
1919 /*
1920 * Check if the slave address received in the data descriptor register
1921 * matches any of the slave addresses registered.
1922 */
1923 slave = mlxbf_i2c_get_slave_from_addr(priv, addr);
1924 if (!slave) {
1925 ret = -EINVAL;
1926 goto clear_csr;
1927 }
1928
1929 /*
1930 * Notify the slave backend that an smbus master wants to write data
1931 * to the BlueField.
1932 */
1933 i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value);
1934
1935 /* Send the received data to the slave backend. */
1936 for (byte = 1; byte < recv_bytes; byte++) {
1937 value = data_desc[byte];
1938 ret = i2c_slave_event(slave, I2C_SLAVE_WRITE_RECEIVED,
1939 &value);
1940 if (ret < 0)
1941 break;
1942 }
1943
1944 /*
1945 * Send a stop event to the slave backend, to signal
1946 * the end of the write transactions.
1947 */
1948 i2c_slave_event(slave, I2C_SLAVE_STOP, &value);
1949
1950 clear_csr:
1951 /* Release the Slave GW. */
1952 writel(0x0, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES);
1953 writel(0x0, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_PEC);
1954 writel(0x1, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_READY);
1955
1956 return ret;
1957 }
1958
mlxbf_i2c_irq(int irq,void * ptr)1959 static irqreturn_t mlxbf_i2c_irq(int irq, void *ptr)
1960 {
1961 struct mlxbf_i2c_priv *priv = ptr;
1962 bool read, write, irq_is_set;
1963 u32 rw_bytes_reg;
1964 u8 recv_bytes;
1965
1966 /*
1967 * Read TYU interrupt register and determine the source of the
1968 * interrupt. Based on the source of the interrupt one of the
1969 * following actions are performed:
1970 * - Receive data and send response to master.
1971 * - Send data and release slave GW.
1972 *
1973 * Handle read/write transaction only. CRmaster and Iarp requests
1974 * are ignored for now.
1975 */
1976 irq_is_set = mlxbf_i2c_has_coalesce(priv, &read, &write);
1977 if (!irq_is_set || (!read && !write)) {
1978 /* Nothing to do here, interrupt was not from this device. */
1979 return IRQ_NONE;
1980 }
1981
1982 /*
1983 * The MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES includes the number of
1984 * bytes from/to master. These are defined by 8-bits each. If the lower
1985 * 8 bits are set, then the master expect to read N bytes from the
1986 * slave, if the higher 8 bits are sent then the slave expect N bytes
1987 * from the master.
1988 */
1989 rw_bytes_reg = readl(priv->slv->io +
1990 MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES);
1991 recv_bytes = (rw_bytes_reg >> 8) & GENMASK(7, 0);
1992
1993 /*
1994 * For now, the slave supports 128 bytes transfer. Discard remaining
1995 * data bytes if the master wrote more than
1996 * MLXBF_I2C_SLAVE_DATA_DESC_SIZE, i.e, the actual size of the slave
1997 * data descriptor.
1998 *
1999 * Note that we will never expect to transfer more than 128 bytes; as
2000 * specified in the SMBus standard, block transactions cannot exceed
2001 * 32 bytes.
2002 */
2003 recv_bytes = recv_bytes > MLXBF_I2C_SLAVE_DATA_DESC_SIZE ?
2004 MLXBF_I2C_SLAVE_DATA_DESC_SIZE : recv_bytes;
2005
2006 if (read)
2007 mlxbf_i2c_irq_send(priv, recv_bytes);
2008 else
2009 mlxbf_i2c_irq_recv(priv, recv_bytes);
2010
2011 return IRQ_HANDLED;
2012 }
2013
2014 /* Return negative errno on error. */
mlxbf_i2c_smbus_xfer(struct i2c_adapter * adap,u16 addr,unsigned short flags,char read_write,u8 command,int size,union i2c_smbus_data * data)2015 static s32 mlxbf_i2c_smbus_xfer(struct i2c_adapter *adap, u16 addr,
2016 unsigned short flags, char read_write,
2017 u8 command, int size,
2018 union i2c_smbus_data *data)
2019 {
2020 struct mlxbf_i2c_smbus_request request = { 0 };
2021 struct mlxbf_i2c_priv *priv;
2022 bool read, pec;
2023 u8 byte_cnt;
2024
2025 request.slave = addr;
2026
2027 read = (read_write == I2C_SMBUS_READ);
2028 pec = flags & I2C_FUNC_SMBUS_PEC;
2029
2030 switch (size) {
2031 case I2C_SMBUS_QUICK:
2032 mlxbf_i2c_smbus_quick_command(&request, read);
2033 dev_dbg(&adap->dev, "smbus quick, slave 0x%02x\n", addr);
2034 break;
2035
2036 case I2C_SMBUS_BYTE:
2037 mlxbf_i2c_smbus_byte_func(&request,
2038 read ? &data->byte : &command, read,
2039 pec);
2040 dev_dbg(&adap->dev, "smbus %s byte, slave 0x%02x.\n",
2041 read ? "read" : "write", addr);
2042 break;
2043
2044 case I2C_SMBUS_BYTE_DATA:
2045 mlxbf_i2c_smbus_data_byte_func(&request, &command, &data->byte,
2046 read, pec);
2047 dev_dbg(&adap->dev, "smbus %s byte data at 0x%02x, slave 0x%02x.\n",
2048 read ? "read" : "write", command, addr);
2049 break;
2050
2051 case I2C_SMBUS_WORD_DATA:
2052 mlxbf_i2c_smbus_data_word_func(&request, &command,
2053 (u8 *)&data->word, read, pec);
2054 dev_dbg(&adap->dev, "smbus %s word data at 0x%02x, slave 0x%02x.\n",
2055 read ? "read" : "write", command, addr);
2056 break;
2057
2058 case I2C_SMBUS_I2C_BLOCK_DATA:
2059 byte_cnt = data->block[0];
2060 mlxbf_i2c_smbus_i2c_block_func(&request, &command, data->block,
2061 &byte_cnt, read, pec);
2062 dev_dbg(&adap->dev, "i2c %s block data, %d bytes at 0x%02x, slave 0x%02x.\n",
2063 read ? "read" : "write", byte_cnt, command, addr);
2064 break;
2065
2066 case I2C_SMBUS_BLOCK_DATA:
2067 byte_cnt = read ? I2C_SMBUS_BLOCK_MAX : data->block[0];
2068 mlxbf_i2c_smbus_block_func(&request, &command, data->block,
2069 &byte_cnt, read, pec);
2070 dev_dbg(&adap->dev, "smbus %s block data, %d bytes at 0x%02x, slave 0x%02x.\n",
2071 read ? "read" : "write", byte_cnt, command, addr);
2072 break;
2073
2074 case I2C_FUNC_SMBUS_PROC_CALL:
2075 mlxbf_i2c_smbus_process_call_func(&request, &command,
2076 (u8 *)&data->word, pec);
2077 dev_dbg(&adap->dev, "process call, wr/rd at 0x%02x, slave 0x%02x.\n",
2078 command, addr);
2079 break;
2080
2081 case I2C_FUNC_SMBUS_BLOCK_PROC_CALL:
2082 byte_cnt = data->block[0];
2083 mlxbf_i2c_smbus_blk_process_call_func(&request, &command,
2084 data->block, &byte_cnt,
2085 pec);
2086 dev_dbg(&adap->dev, "block process call, wr/rd %d bytes, slave 0x%02x.\n",
2087 byte_cnt, addr);
2088 break;
2089
2090 default:
2091 dev_dbg(&adap->dev, "Unsupported I2C/SMBus command %d\n",
2092 size);
2093 return -EOPNOTSUPP;
2094 }
2095
2096 priv = i2c_get_adapdata(adap);
2097
2098 return mlxbf_i2c_smbus_start_transaction(priv, &request);
2099 }
2100
mlxbf_i2c_reg_slave(struct i2c_client * slave)2101 static int mlxbf_i2c_reg_slave(struct i2c_client *slave)
2102 {
2103 struct mlxbf_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
2104 struct device *dev = &slave->dev;
2105 int ret;
2106
2107 /*
2108 * Do not support ten bit chip address and do not use Packet Error
2109 * Checking (PEC).
2110 */
2111 if (slave->flags & (I2C_CLIENT_TEN | I2C_CLIENT_PEC)) {
2112 dev_err(dev, "SMBus PEC and 10 bit address not supported\n");
2113 return -EAFNOSUPPORT;
2114 }
2115
2116 ret = mlxbf_i2c_slave_enable(priv, slave);
2117 if (ret)
2118 dev_err(dev, "Surpassed max number of registered slaves allowed\n");
2119
2120 return 0;
2121 }
2122
mlxbf_i2c_unreg_slave(struct i2c_client * slave)2123 static int mlxbf_i2c_unreg_slave(struct i2c_client *slave)
2124 {
2125 struct mlxbf_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
2126 struct device *dev = &slave->dev;
2127 int ret;
2128
2129 /*
2130 * Unregister slave by:
2131 * 1) Disabling the slave address in hardware
2132 * 2) Freeing priv->slave at the corresponding index
2133 */
2134 ret = mlxbf_i2c_slave_disable(priv, slave->addr);
2135 if (ret)
2136 dev_err(dev, "Unable to find slave 0x%x\n", slave->addr);
2137
2138 return ret;
2139 }
2140
mlxbf_i2c_functionality(struct i2c_adapter * adap)2141 static u32 mlxbf_i2c_functionality(struct i2c_adapter *adap)
2142 {
2143 return MLXBF_I2C_FUNC_ALL;
2144 }
2145
2146 static struct mlxbf_i2c_chip_info mlxbf_i2c_chip[] = {
2147 [MLXBF_I2C_CHIP_TYPE_1] = {
2148 .type = MLXBF_I2C_CHIP_TYPE_1,
2149 .shared_res = {
2150 [0] = &mlxbf_i2c_coalesce_res[MLXBF_I2C_CHIP_TYPE_1],
2151 [1] = &mlxbf_i2c_corepll_res[MLXBF_I2C_CHIP_TYPE_1],
2152 [2] = &mlxbf_i2c_gpio_res[MLXBF_I2C_CHIP_TYPE_1]
2153 },
2154 .calculate_freq = mlxbf_i2c_calculate_freq_from_tyu,
2155 .smbus_master_rs_bytes_off = MLXBF_I2C_YU_SMBUS_RS_BYTES,
2156 .smbus_master_fsm_off = MLXBF_I2C_YU_SMBUS_MASTER_FSM
2157 },
2158 [MLXBF_I2C_CHIP_TYPE_2] = {
2159 .type = MLXBF_I2C_CHIP_TYPE_2,
2160 .shared_res = {
2161 [0] = &mlxbf_i2c_corepll_res[MLXBF_I2C_CHIP_TYPE_2]
2162 },
2163 .calculate_freq = mlxbf_i2c_calculate_freq_from_yu,
2164 .smbus_master_rs_bytes_off = MLXBF_I2C_YU_SMBUS_RS_BYTES,
2165 .smbus_master_fsm_off = MLXBF_I2C_YU_SMBUS_MASTER_FSM
2166 },
2167 [MLXBF_I2C_CHIP_TYPE_3] = {
2168 .type = MLXBF_I2C_CHIP_TYPE_3,
2169 .shared_res = {
2170 [0] = &mlxbf_i2c_corepll_res[MLXBF_I2C_CHIP_TYPE_3]
2171 },
2172 .calculate_freq = mlxbf_i2c_calculate_freq_from_yu,
2173 .smbus_master_rs_bytes_off = MLXBF_I2C_RSH_YU_SMBUS_RS_BYTES,
2174 .smbus_master_fsm_off = MLXBF_I2C_RSH_YU_SMBUS_MASTER_FSM
2175 }
2176 };
2177
2178 static const struct i2c_algorithm mlxbf_i2c_algo = {
2179 .smbus_xfer = mlxbf_i2c_smbus_xfer,
2180 .functionality = mlxbf_i2c_functionality,
2181 .reg_slave = mlxbf_i2c_reg_slave,
2182 .unreg_slave = mlxbf_i2c_unreg_slave,
2183 };
2184
2185 static struct i2c_adapter_quirks mlxbf_i2c_quirks = {
2186 .max_read_len = MLXBF_I2C_MASTER_DATA_R_LENGTH,
2187 .max_write_len = MLXBF_I2C_MASTER_DATA_W_LENGTH,
2188 };
2189
2190 static const struct acpi_device_id mlxbf_i2c_acpi_ids[] = {
2191 { "MLNXBF03", (kernel_ulong_t)&mlxbf_i2c_chip[MLXBF_I2C_CHIP_TYPE_1] },
2192 { "MLNXBF23", (kernel_ulong_t)&mlxbf_i2c_chip[MLXBF_I2C_CHIP_TYPE_2] },
2193 { "MLNXBF31", (kernel_ulong_t)&mlxbf_i2c_chip[MLXBF_I2C_CHIP_TYPE_3] },
2194 {},
2195 };
2196
2197 MODULE_DEVICE_TABLE(acpi, mlxbf_i2c_acpi_ids);
2198
mlxbf_i2c_acpi_probe(struct device * dev,struct mlxbf_i2c_priv * priv)2199 static int mlxbf_i2c_acpi_probe(struct device *dev, struct mlxbf_i2c_priv *priv)
2200 {
2201 const struct acpi_device_id *aid;
2202 u64 bus_id;
2203 int ret;
2204
2205 if (acpi_disabled)
2206 return -ENOENT;
2207
2208 aid = acpi_match_device(mlxbf_i2c_acpi_ids, dev);
2209 if (!aid)
2210 return -ENODEV;
2211
2212 priv->chip = (struct mlxbf_i2c_chip_info *)aid->driver_data;
2213
2214 ret = acpi_dev_uid_to_integer(ACPI_COMPANION(dev), &bus_id);
2215 if (ret) {
2216 dev_err(dev, "Cannot retrieve UID\n");
2217 return ret;
2218 }
2219
2220 priv->bus = bus_id;
2221
2222 return 0;
2223 }
2224
mlxbf_i2c_probe(struct platform_device * pdev)2225 static int mlxbf_i2c_probe(struct platform_device *pdev)
2226 {
2227 struct device *dev = &pdev->dev;
2228 struct mlxbf_i2c_priv *priv;
2229 struct i2c_adapter *adap;
2230 u32 resource_version;
2231 int irq, ret;
2232
2233 priv = devm_kzalloc(dev, sizeof(struct mlxbf_i2c_priv), GFP_KERNEL);
2234 if (!priv)
2235 return -ENOMEM;
2236
2237 ret = mlxbf_i2c_acpi_probe(dev, priv);
2238 if (ret < 0)
2239 return ret;
2240
2241 /* This property allows the driver to stay backward compatible with older
2242 * ACPI tables.
2243 * Starting BlueField-3 SoC, the "smbus" resource was broken down into 3
2244 * separate resources "timer", "master" and "slave".
2245 */
2246 if (device_property_read_u32(dev, "resource_version", &resource_version))
2247 resource_version = 0;
2248
2249 priv->resource_version = resource_version;
2250
2251 if (priv->chip->type < MLXBF_I2C_CHIP_TYPE_3 && resource_version == 0) {
2252 priv->timer = devm_kzalloc(dev, sizeof(struct mlxbf_i2c_resource), GFP_KERNEL);
2253 if (!priv->timer)
2254 return -ENOMEM;
2255
2256 priv->mst = devm_kzalloc(dev, sizeof(struct mlxbf_i2c_resource), GFP_KERNEL);
2257 if (!priv->mst)
2258 return -ENOMEM;
2259
2260 priv->slv = devm_kzalloc(dev, sizeof(struct mlxbf_i2c_resource), GFP_KERNEL);
2261 if (!priv->slv)
2262 return -ENOMEM;
2263
2264 ret = mlxbf_i2c_init_resource(pdev, &priv->smbus,
2265 MLXBF_I2C_SMBUS_RES);
2266 if (ret < 0)
2267 return dev_err_probe(dev, ret, "Cannot fetch smbus resource info");
2268
2269 priv->timer->io = priv->smbus->io;
2270 priv->mst->io = priv->smbus->io + MLXBF_I2C_MST_ADDR_OFFSET;
2271 priv->slv->io = priv->smbus->io + MLXBF_I2C_SLV_ADDR_OFFSET;
2272 } else {
2273 ret = mlxbf_i2c_init_resource(pdev, &priv->timer,
2274 MLXBF_I2C_SMBUS_TIMER_RES);
2275 if (ret < 0)
2276 return dev_err_probe(dev, ret, "Cannot fetch timer resource info");
2277
2278 ret = mlxbf_i2c_init_resource(pdev, &priv->mst,
2279 MLXBF_I2C_SMBUS_MST_RES);
2280 if (ret < 0)
2281 return dev_err_probe(dev, ret, "Cannot fetch master resource info");
2282
2283 ret = mlxbf_i2c_init_resource(pdev, &priv->slv,
2284 MLXBF_I2C_SMBUS_SLV_RES);
2285 if (ret < 0)
2286 return dev_err_probe(dev, ret, "Cannot fetch slave resource info");
2287 }
2288
2289 ret = mlxbf_i2c_init_resource(pdev, &priv->mst_cause,
2290 MLXBF_I2C_MST_CAUSE_RES);
2291 if (ret < 0)
2292 return dev_err_probe(dev, ret, "Cannot fetch cause master resource info");
2293
2294 ret = mlxbf_i2c_init_resource(pdev, &priv->slv_cause,
2295 MLXBF_I2C_SLV_CAUSE_RES);
2296 if (ret < 0)
2297 return dev_err_probe(dev, ret, "Cannot fetch cause slave resource info");
2298
2299 adap = &priv->adap;
2300 adap->owner = THIS_MODULE;
2301 adap->class = I2C_CLASS_HWMON;
2302 adap->algo = &mlxbf_i2c_algo;
2303 adap->quirks = &mlxbf_i2c_quirks;
2304 adap->dev.parent = dev;
2305 adap->dev.of_node = dev->of_node;
2306 adap->nr = priv->bus;
2307
2308 snprintf(adap->name, sizeof(adap->name), "i2c%d", adap->nr);
2309 i2c_set_adapdata(adap, priv);
2310
2311 /* Read Core PLL frequency. */
2312 ret = mlxbf_i2c_calculate_corepll_freq(pdev, priv);
2313 if (ret < 0) {
2314 dev_err(dev, "cannot get core clock frequency\n");
2315 /* Set to default value. */
2316 priv->frequency = MLXBF_I2C_COREPLL_FREQ;
2317 }
2318
2319 /*
2320 * Initialize master.
2321 * Note that a physical bus might be shared among Linux and firmware
2322 * (e.g., ATF). Thus, the bus should be initialized and ready and
2323 * bus initialization would be unnecessary. This requires additional
2324 * knowledge about physical busses. But, since an extra initialization
2325 * does not really hurt, then keep the code as is.
2326 */
2327 ret = mlxbf_i2c_init_master(pdev, priv);
2328 if (ret < 0)
2329 return dev_err_probe(dev, ret, "failed to initialize smbus master %d",
2330 priv->bus);
2331
2332 mlxbf_i2c_init_timings(pdev, priv);
2333
2334 mlxbf_i2c_init_slave(pdev, priv);
2335
2336 irq = platform_get_irq(pdev, 0);
2337 if (irq < 0)
2338 return irq;
2339 ret = devm_request_irq(dev, irq, mlxbf_i2c_irq,
2340 IRQF_SHARED | IRQF_PROBE_SHARED,
2341 dev_name(dev), priv);
2342 if (ret < 0)
2343 return dev_err_probe(dev, ret, "Cannot get irq %d\n", irq);
2344
2345 priv->irq = irq;
2346
2347 platform_set_drvdata(pdev, priv);
2348
2349 ret = i2c_add_numbered_adapter(adap);
2350 if (ret < 0)
2351 return ret;
2352
2353 mutex_lock(&mlxbf_i2c_bus_lock);
2354 mlxbf_i2c_bus_count++;
2355 mutex_unlock(&mlxbf_i2c_bus_lock);
2356
2357 return 0;
2358 }
2359
mlxbf_i2c_remove(struct platform_device * pdev)2360 static void mlxbf_i2c_remove(struct platform_device *pdev)
2361 {
2362 struct mlxbf_i2c_priv *priv = platform_get_drvdata(pdev);
2363 struct device *dev = &pdev->dev;
2364 struct resource *params;
2365
2366 if (priv->chip->type < MLXBF_I2C_CHIP_TYPE_3 && priv->resource_version == 0) {
2367 params = priv->smbus->params;
2368 devm_release_mem_region(dev, params->start, resource_size(params));
2369 } else {
2370 params = priv->timer->params;
2371 devm_release_mem_region(dev, params->start, resource_size(params));
2372
2373 params = priv->mst->params;
2374 devm_release_mem_region(dev, params->start, resource_size(params));
2375
2376 params = priv->slv->params;
2377 devm_release_mem_region(dev, params->start, resource_size(params));
2378 }
2379
2380 params = priv->mst_cause->params;
2381 devm_release_mem_region(dev, params->start, resource_size(params));
2382
2383 params = priv->slv_cause->params;
2384 devm_release_mem_region(dev, params->start, resource_size(params));
2385
2386 /*
2387 * Release shared resources. This should be done when releasing
2388 * the I2C controller.
2389 */
2390 mutex_lock(&mlxbf_i2c_bus_lock);
2391 if (--mlxbf_i2c_bus_count == 0) {
2392 mlxbf_i2c_release_coalesce(pdev, priv);
2393 mlxbf_i2c_release_corepll(pdev, priv);
2394 mlxbf_i2c_release_gpio(pdev, priv);
2395 }
2396 mutex_unlock(&mlxbf_i2c_bus_lock);
2397
2398 devm_free_irq(dev, priv->irq, priv);
2399
2400 i2c_del_adapter(&priv->adap);
2401 }
2402
2403 static struct platform_driver mlxbf_i2c_driver = {
2404 .probe = mlxbf_i2c_probe,
2405 .remove = mlxbf_i2c_remove,
2406 .driver = {
2407 .name = "i2c-mlxbf",
2408 .acpi_match_table = ACPI_PTR(mlxbf_i2c_acpi_ids),
2409 },
2410 };
2411
mlxbf_i2c_init(void)2412 static int __init mlxbf_i2c_init(void)
2413 {
2414 mutex_init(&mlxbf_i2c_coalesce_lock);
2415 mutex_init(&mlxbf_i2c_corepll_lock);
2416 mutex_init(&mlxbf_i2c_gpio_lock);
2417
2418 mutex_init(&mlxbf_i2c_bus_lock);
2419
2420 return platform_driver_register(&mlxbf_i2c_driver);
2421 }
2422 module_init(mlxbf_i2c_init);
2423
mlxbf_i2c_exit(void)2424 static void __exit mlxbf_i2c_exit(void)
2425 {
2426 platform_driver_unregister(&mlxbf_i2c_driver);
2427
2428 mutex_destroy(&mlxbf_i2c_bus_lock);
2429
2430 mutex_destroy(&mlxbf_i2c_gpio_lock);
2431 mutex_destroy(&mlxbf_i2c_corepll_lock);
2432 mutex_destroy(&mlxbf_i2c_coalesce_lock);
2433 }
2434 module_exit(mlxbf_i2c_exit);
2435
2436 MODULE_DESCRIPTION("Mellanox BlueField I2C bus driver");
2437 MODULE_AUTHOR("Khalil Blaiech <kblaiech@nvidia.com>");
2438 MODULE_AUTHOR("Asmaa Mnebhi <asmaa@nvidia.com>");
2439 MODULE_LICENSE("GPL v2");
2440