1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Synopsys DesignWare I2C adapter driver.
4 *
5 * Based on the TI DAVINCI I2C adapter driver.
6 *
7 * Copyright (C) 2006 Texas Instruments.
8 * Copyright (C) 2007 MontaVista Software Inc.
9 * Copyright (C) 2009 Provigent Ltd.
10 */
11 #include <linux/acpi.h>
12 #include <linux/clk-provider.h>
13 #include <linux/clk.h>
14 #include <linux/delay.h>
15 #include <linux/dmi.h>
16 #include <linux/err.h>
17 #include <linux/errno.h>
18 #include <linux/i2c.h>
19 #include <linux/interrupt.h>
20 #include <linux/io.h>
21 #include <linux/kernel.h>
22 #include <linux/mfd/syscon.h>
23 #include <linux/module.h>
24 #include <linux/of.h>
25 #include <linux/platform_data/i2c-designware.h>
26 #include <linux/platform_device.h>
27 #include <linux/pm.h>
28 #include <linux/pm_runtime.h>
29 #include <linux/property.h>
30 #include <linux/regmap.h>
31 #include <linux/reset.h>
32 #include <linux/sched.h>
33 #include <linux/slab.h>
34 #include <linux/suspend.h>
35
36 #include "i2c-designware-core.h"
37
i2c_dw_get_clk_rate_khz(struct dw_i2c_dev * dev)38 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
39 {
40 return clk_get_rate(dev->clk)/1000;
41 }
42
43 #ifdef CONFIG_ACPI
44 static const struct acpi_device_id dw_i2c_acpi_match[] = {
45 { "INT33C2", 0 },
46 { "INT33C3", 0 },
47 { "INT3432", 0 },
48 { "INT3433", 0 },
49 { "80860F41", ACCESS_NO_IRQ_SUSPEND },
50 { "808622C1", ACCESS_NO_IRQ_SUSPEND },
51 { "AMD0010", ACCESS_INTR_MASK },
52 { "AMDI0010", ACCESS_INTR_MASK },
53 { "AMDI0510", 0 },
54 { "APMC0D0F", 0 },
55 { "HISI02A1", 0 },
56 { "HISI02A2", 0 },
57 { "HISI02A3", 0 },
58 { "HYGO0010", ACCESS_INTR_MASK },
59 { }
60 };
61 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
62 #endif
63
64 #ifdef CONFIG_OF
65 #define BT1_I2C_CTL 0x100
66 #define BT1_I2C_CTL_ADDR_MASK GENMASK(7, 0)
67 #define BT1_I2C_CTL_WR BIT(8)
68 #define BT1_I2C_CTL_GO BIT(31)
69 #define BT1_I2C_DI 0x104
70 #define BT1_I2C_DO 0x108
71
bt1_i2c_read(void * context,unsigned int reg,unsigned int * val)72 static int bt1_i2c_read(void *context, unsigned int reg, unsigned int *val)
73 {
74 struct dw_i2c_dev *dev = context;
75 int ret;
76
77 /*
78 * Note these methods shouldn't ever fail because the system controller
79 * registers are memory mapped. We check the return value just in case.
80 */
81 ret = regmap_write(dev->sysmap, BT1_I2C_CTL,
82 BT1_I2C_CTL_GO | (reg & BT1_I2C_CTL_ADDR_MASK));
83 if (ret)
84 return ret;
85
86 return regmap_read(dev->sysmap, BT1_I2C_DO, val);
87 }
88
bt1_i2c_write(void * context,unsigned int reg,unsigned int val)89 static int bt1_i2c_write(void *context, unsigned int reg, unsigned int val)
90 {
91 struct dw_i2c_dev *dev = context;
92 int ret;
93
94 ret = regmap_write(dev->sysmap, BT1_I2C_DI, val);
95 if (ret)
96 return ret;
97
98 return regmap_write(dev->sysmap, BT1_I2C_CTL,
99 BT1_I2C_CTL_GO | BT1_I2C_CTL_WR | (reg & BT1_I2C_CTL_ADDR_MASK));
100 }
101
102 static struct regmap_config bt1_i2c_cfg = {
103 .reg_bits = 32,
104 .val_bits = 32,
105 .reg_stride = 4,
106 .fast_io = true,
107 .reg_read = bt1_i2c_read,
108 .reg_write = bt1_i2c_write,
109 .max_register = DW_IC_COMP_TYPE,
110 };
111
bt1_i2c_request_regs(struct dw_i2c_dev * dev)112 static int bt1_i2c_request_regs(struct dw_i2c_dev *dev)
113 {
114 dev->sysmap = syscon_node_to_regmap(dev->dev->of_node->parent);
115 if (IS_ERR(dev->sysmap))
116 return PTR_ERR(dev->sysmap);
117
118 dev->map = devm_regmap_init(dev->dev, NULL, dev, &bt1_i2c_cfg);
119 return PTR_ERR_OR_ZERO(dev->map);
120 }
121
122 #define MSCC_ICPU_CFG_TWI_DELAY 0x0
123 #define MSCC_ICPU_CFG_TWI_DELAY_ENABLE BIT(0)
124 #define MSCC_ICPU_CFG_TWI_SPIKE_FILTER 0x4
125
mscc_twi_set_sda_hold_time(struct dw_i2c_dev * dev)126 static int mscc_twi_set_sda_hold_time(struct dw_i2c_dev *dev)
127 {
128 writel((dev->sda_hold_time << 1) | MSCC_ICPU_CFG_TWI_DELAY_ENABLE,
129 dev->ext + MSCC_ICPU_CFG_TWI_DELAY);
130
131 return 0;
132 }
133
dw_i2c_of_configure(struct platform_device * pdev)134 static int dw_i2c_of_configure(struct platform_device *pdev)
135 {
136 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
137
138 switch (dev->flags & MODEL_MASK) {
139 case MODEL_MSCC_OCELOT:
140 dev->ext = devm_platform_ioremap_resource(pdev, 1);
141 if (!IS_ERR(dev->ext))
142 dev->set_sda_hold_time = mscc_twi_set_sda_hold_time;
143 break;
144 default:
145 break;
146 }
147
148 return 0;
149 }
150
151 static const struct of_device_id dw_i2c_of_match[] = {
152 { .compatible = "snps,designware-i2c", },
153 { .compatible = "mscc,ocelot-i2c", .data = (void *)MODEL_MSCC_OCELOT },
154 { .compatible = "baikal,bt1-sys-i2c", .data = (void *)MODEL_BAIKAL_BT1 },
155 {},
156 };
157 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
158 #else
bt1_i2c_request_regs(struct dw_i2c_dev * dev)159 static int bt1_i2c_request_regs(struct dw_i2c_dev *dev)
160 {
161 return -ENODEV;
162 }
163
dw_i2c_of_configure(struct platform_device * pdev)164 static inline int dw_i2c_of_configure(struct platform_device *pdev)
165 {
166 return -ENODEV;
167 }
168 #endif
169
dw_i2c_plat_pm_cleanup(struct dw_i2c_dev * dev)170 static void dw_i2c_plat_pm_cleanup(struct dw_i2c_dev *dev)
171 {
172 pm_runtime_disable(dev->dev);
173
174 if (dev->shared_with_punit)
175 pm_runtime_put_noidle(dev->dev);
176 }
177
dw_i2c_plat_request_regs(struct dw_i2c_dev * dev)178 static int dw_i2c_plat_request_regs(struct dw_i2c_dev *dev)
179 {
180 struct platform_device *pdev = to_platform_device(dev->dev);
181 int ret;
182
183 switch (dev->flags & MODEL_MASK) {
184 case MODEL_BAIKAL_BT1:
185 ret = bt1_i2c_request_regs(dev);
186 break;
187 default:
188 dev->base = devm_platform_ioremap_resource(pdev, 0);
189 ret = PTR_ERR_OR_ZERO(dev->base);
190 break;
191 }
192
193 return ret;
194 }
195
196 static const struct dmi_system_id dw_i2c_hwmon_class_dmi[] = {
197 {
198 .ident = "Qtechnology QT5222",
199 .matches = {
200 DMI_MATCH(DMI_SYS_VENDOR, "Qtechnology"),
201 DMI_MATCH(DMI_PRODUCT_NAME, "QT5222"),
202 },
203 },
204 { } /* terminate list */
205 };
206
dw_i2c_plat_probe(struct platform_device * pdev)207 static int dw_i2c_plat_probe(struct platform_device *pdev)
208 {
209 struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
210 struct i2c_adapter *adap;
211 struct dw_i2c_dev *dev;
212 struct i2c_timings *t;
213 int irq, ret;
214
215 irq = platform_get_irq(pdev, 0);
216 if (irq < 0)
217 return irq;
218
219 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
220 if (!dev)
221 return -ENOMEM;
222
223 dev->flags = (uintptr_t)device_get_match_data(&pdev->dev);
224 dev->dev = &pdev->dev;
225 dev->irq = irq;
226 platform_set_drvdata(pdev, dev);
227
228 ret = dw_i2c_plat_request_regs(dev);
229 if (ret)
230 return ret;
231
232 dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
233 if (IS_ERR(dev->rst))
234 return PTR_ERR(dev->rst);
235
236 reset_control_deassert(dev->rst);
237
238 t = &dev->timings;
239 if (pdata)
240 t->bus_freq_hz = pdata->i2c_scl_freq;
241 else
242 i2c_parse_fw_timings(&pdev->dev, t, false);
243
244 i2c_dw_adjust_bus_speed(dev);
245
246 if (pdev->dev.of_node)
247 dw_i2c_of_configure(pdev);
248
249 if (has_acpi_companion(&pdev->dev))
250 i2c_dw_acpi_configure(&pdev->dev);
251
252 ret = i2c_dw_validate_speed(dev);
253 if (ret)
254 goto exit_reset;
255
256 ret = i2c_dw_probe_lock_support(dev);
257 if (ret)
258 goto exit_reset;
259
260 i2c_dw_configure(dev);
261
262 /* Optional interface clock */
263 dev->pclk = devm_clk_get_optional(&pdev->dev, "pclk");
264 if (IS_ERR(dev->pclk)) {
265 ret = PTR_ERR(dev->pclk);
266 goto exit_reset;
267 }
268
269 dev->clk = devm_clk_get(&pdev->dev, NULL);
270 if (!i2c_dw_prepare_clk(dev, true)) {
271 u64 clk_khz;
272
273 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
274 clk_khz = dev->get_clk_rate_khz(dev);
275
276 if (!dev->sda_hold_time && t->sda_hold_ns)
277 dev->sda_hold_time =
278 div_u64(clk_khz * t->sda_hold_ns + 500000, 1000000);
279 }
280
281 adap = &dev->adapter;
282 adap->owner = THIS_MODULE;
283 adap->class = dmi_check_system(dw_i2c_hwmon_class_dmi) ?
284 I2C_CLASS_HWMON : I2C_CLASS_DEPRECATED;
285 ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
286 adap->dev.of_node = pdev->dev.of_node;
287 adap->nr = -1;
288
289 if (dev->flags & ACCESS_NO_IRQ_SUSPEND) {
290 dev_pm_set_driver_flags(&pdev->dev,
291 DPM_FLAG_SMART_PREPARE |
292 DPM_FLAG_MAY_SKIP_RESUME);
293 } else {
294 dev_pm_set_driver_flags(&pdev->dev,
295 DPM_FLAG_SMART_PREPARE |
296 DPM_FLAG_SMART_SUSPEND |
297 DPM_FLAG_MAY_SKIP_RESUME);
298 }
299
300 /* The code below assumes runtime PM to be disabled. */
301 WARN_ON(pm_runtime_enabled(&pdev->dev));
302
303 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
304 pm_runtime_use_autosuspend(&pdev->dev);
305 pm_runtime_set_active(&pdev->dev);
306
307 if (dev->shared_with_punit)
308 pm_runtime_get_noresume(&pdev->dev);
309
310 pm_runtime_enable(&pdev->dev);
311
312 ret = i2c_dw_probe(dev);
313 if (ret)
314 goto exit_probe;
315
316 return ret;
317
318 exit_probe:
319 dw_i2c_plat_pm_cleanup(dev);
320 exit_reset:
321 reset_control_assert(dev->rst);
322 return ret;
323 }
324
dw_i2c_plat_remove(struct platform_device * pdev)325 static int dw_i2c_plat_remove(struct platform_device *pdev)
326 {
327 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
328
329 pm_runtime_get_sync(&pdev->dev);
330
331 i2c_del_adapter(&dev->adapter);
332
333 dev->disable(dev);
334
335 pm_runtime_dont_use_autosuspend(&pdev->dev);
336 pm_runtime_put_sync(&pdev->dev);
337 dw_i2c_plat_pm_cleanup(dev);
338
339 reset_control_assert(dev->rst);
340
341 return 0;
342 }
343
344 #ifdef CONFIG_PM_SLEEP
dw_i2c_plat_prepare(struct device * dev)345 static int dw_i2c_plat_prepare(struct device *dev)
346 {
347 /*
348 * If the ACPI companion device object is present for this device, it
349 * may be accessed during suspend and resume of other devices via I2C
350 * operation regions, so tell the PM core and middle layers to avoid
351 * skipping system suspend/resume callbacks for it in that case.
352 */
353 return !has_acpi_companion(dev);
354 }
355
dw_i2c_plat_complete(struct device * dev)356 static void dw_i2c_plat_complete(struct device *dev)
357 {
358 /*
359 * The device can only be in runtime suspend at this point if it has not
360 * been resumed throughout the ending system suspend/resume cycle, so if
361 * the platform firmware might mess up with it, request the runtime PM
362 * framework to resume it.
363 */
364 if (pm_runtime_suspended(dev) && pm_resume_via_firmware())
365 pm_request_resume(dev);
366 }
367 #else
368 #define dw_i2c_plat_prepare NULL
369 #define dw_i2c_plat_complete NULL
370 #endif
371
372 #ifdef CONFIG_PM
dw_i2c_plat_suspend(struct device * dev)373 static int dw_i2c_plat_suspend(struct device *dev)
374 {
375 struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
376
377 i_dev->suspended = true;
378
379 if (i_dev->shared_with_punit)
380 return 0;
381
382 i_dev->disable(i_dev);
383 i2c_dw_prepare_clk(i_dev, false);
384
385 return 0;
386 }
387
dw_i2c_plat_resume(struct device * dev)388 static int dw_i2c_plat_resume(struct device *dev)
389 {
390 struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
391
392 if (!i_dev->shared_with_punit)
393 i2c_dw_prepare_clk(i_dev, true);
394
395 i_dev->init(i_dev);
396 i_dev->suspended = false;
397
398 return 0;
399 }
400
401 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
402 .prepare = dw_i2c_plat_prepare,
403 .complete = dw_i2c_plat_complete,
404 SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
405 SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
406 };
407
408 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
409 #else
410 #define DW_I2C_DEV_PMOPS NULL
411 #endif
412
413 /* Work with hotplug and coldplug */
414 MODULE_ALIAS("platform:i2c_designware");
415
416 static struct platform_driver dw_i2c_driver = {
417 .probe = dw_i2c_plat_probe,
418 .remove = dw_i2c_plat_remove,
419 .driver = {
420 .name = "i2c_designware",
421 .of_match_table = of_match_ptr(dw_i2c_of_match),
422 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
423 .pm = DW_I2C_DEV_PMOPS,
424 },
425 };
426
dw_i2c_init_driver(void)427 static int __init dw_i2c_init_driver(void)
428 {
429 return platform_driver_register(&dw_i2c_driver);
430 }
431 subsys_initcall(dw_i2c_init_driver);
432
dw_i2c_exit_driver(void)433 static void __exit dw_i2c_exit_driver(void)
434 {
435 platform_driver_unregister(&dw_i2c_driver);
436 }
437 module_exit(dw_i2c_exit_driver);
438
439 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
440 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
441 MODULE_LICENSE("GPL");
442