1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * MediaTek PCIe host controller driver.
4  *
5  * Copyright (c) 2020 MediaTek Inc.
6  * Author: Jianjun Wang <jianjun.wang@mediatek.com>
7  */
8 
9 #include <linux/bitfield.h>
10 #include <linux/clk.h>
11 #include <linux/clk-provider.h>
12 #include <linux/delay.h>
13 #include <linux/iopoll.h>
14 #include <linux/irq.h>
15 #include <linux/irqchip/chained_irq.h>
16 #include <linux/irqdomain.h>
17 #include <linux/kernel.h>
18 #include <linux/mfd/syscon.h>
19 #include <linux/module.h>
20 #include <linux/msi.h>
21 #include <linux/of_device.h>
22 #include <linux/of_pci.h>
23 #include <linux/pci.h>
24 #include <linux/phy/phy.h>
25 #include <linux/platform_device.h>
26 #include <linux/pm_domain.h>
27 #include <linux/pm_runtime.h>
28 #include <linux/regmap.h>
29 #include <linux/reset.h>
30 
31 #include "../pci.h"
32 
33 #define PCIE_BASE_CFG_REG		0x14
34 #define PCIE_BASE_CFG_SPEED		GENMASK(15, 8)
35 
36 #define PCIE_SETTING_REG		0x80
37 #define PCIE_SETTING_LINK_WIDTH		GENMASK(11, 8)
38 #define PCIE_SETTING_GEN_SUPPORT	GENMASK(14, 12)
39 #define PCIE_PCI_IDS_1			0x9c
40 #define PCI_CLASS(class)		(class << 8)
41 #define PCIE_RC_MODE			BIT(0)
42 
43 #define PCIE_EQ_PRESET_01_REG		0x100
44 #define PCIE_VAL_LN0_DOWNSTREAM		GENMASK(6, 0)
45 #define PCIE_VAL_LN0_UPSTREAM		GENMASK(14, 8)
46 #define PCIE_VAL_LN1_DOWNSTREAM		GENMASK(22, 16)
47 #define PCIE_VAL_LN1_UPSTREAM		GENMASK(30, 24)
48 
49 #define PCIE_CFGNUM_REG			0x140
50 #define PCIE_CFG_DEVFN(devfn)		((devfn) & GENMASK(7, 0))
51 #define PCIE_CFG_BUS(bus)		(((bus) << 8) & GENMASK(15, 8))
52 #define PCIE_CFG_BYTE_EN(bytes)		(((bytes) << 16) & GENMASK(19, 16))
53 #define PCIE_CFG_FORCE_BYTE_EN		BIT(20)
54 #define PCIE_CFG_OFFSET_ADDR		0x1000
55 #define PCIE_CFG_HEADER(bus, devfn) \
56 	(PCIE_CFG_BUS(bus) | PCIE_CFG_DEVFN(devfn))
57 
58 #define PCIE_RST_CTRL_REG		0x148
59 #define PCIE_MAC_RSTB			BIT(0)
60 #define PCIE_PHY_RSTB			BIT(1)
61 #define PCIE_BRG_RSTB			BIT(2)
62 #define PCIE_PE_RSTB			BIT(3)
63 
64 #define PCIE_LTSSM_STATUS_REG		0x150
65 #define PCIE_LTSSM_STATE_MASK		GENMASK(28, 24)
66 #define PCIE_LTSSM_STATE(val)		((val & PCIE_LTSSM_STATE_MASK) >> 24)
67 #define PCIE_LTSSM_STATE_L2_IDLE	0x14
68 
69 #define PCIE_LINK_STATUS_REG		0x154
70 #define PCIE_PORT_LINKUP		BIT(8)
71 
72 #define PCIE_MSI_SET_NUM		8
73 #define PCIE_MSI_IRQS_PER_SET		32
74 #define PCIE_MSI_IRQS_NUM \
75 	(PCIE_MSI_IRQS_PER_SET * PCIE_MSI_SET_NUM)
76 
77 #define PCIE_INT_ENABLE_REG		0x180
78 #define PCIE_MSI_ENABLE			GENMASK(PCIE_MSI_SET_NUM + 8 - 1, 8)
79 #define PCIE_MSI_SHIFT			8
80 #define PCIE_INTX_SHIFT			24
81 #define PCIE_INTX_ENABLE \
82 	GENMASK(PCIE_INTX_SHIFT + PCI_NUM_INTX - 1, PCIE_INTX_SHIFT)
83 
84 #define PCIE_INT_STATUS_REG		0x184
85 #define PCIE_MSI_SET_ENABLE_REG		0x190
86 #define PCIE_MSI_SET_ENABLE		GENMASK(PCIE_MSI_SET_NUM - 1, 0)
87 
88 #define PCIE_PIPE4_PIE8_REG		0x338
89 #define PCIE_K_FINETUNE_MAX		GENMASK(5, 0)
90 #define PCIE_K_FINETUNE_ERR		GENMASK(7, 6)
91 #define PCIE_K_PRESET_TO_USE		GENMASK(18, 8)
92 #define PCIE_K_PHYPARAM_QUERY		BIT(19)
93 #define PCIE_K_QUERY_TIMEOUT		BIT(20)
94 #define PCIE_K_PRESET_TO_USE_16G	GENMASK(31, 21)
95 
96 #define PCIE_MSI_SET_BASE_REG		0xc00
97 #define PCIE_MSI_SET_OFFSET		0x10
98 #define PCIE_MSI_SET_STATUS_OFFSET	0x04
99 #define PCIE_MSI_SET_ENABLE_OFFSET	0x08
100 
101 #define PCIE_MSI_SET_ADDR_HI_BASE	0xc80
102 #define PCIE_MSI_SET_ADDR_HI_OFFSET	0x04
103 
104 #define PCIE_ICMD_PM_REG		0x198
105 #define PCIE_TURN_OFF_LINK		BIT(4)
106 
107 #define PCIE_MISC_CTRL_REG		0x348
108 #define PCIE_DISABLE_DVFSRC_VLT_REQ	BIT(1)
109 
110 #define PCIE_TRANS_TABLE_BASE_REG	0x800
111 #define PCIE_ATR_SRC_ADDR_MSB_OFFSET	0x4
112 #define PCIE_ATR_TRSL_ADDR_LSB_OFFSET	0x8
113 #define PCIE_ATR_TRSL_ADDR_MSB_OFFSET	0xc
114 #define PCIE_ATR_TRSL_PARAM_OFFSET	0x10
115 #define PCIE_ATR_TLB_SET_OFFSET		0x20
116 
117 #define PCIE_MAX_TRANS_TABLES		8
118 #define PCIE_ATR_EN			BIT(0)
119 #define PCIE_ATR_SIZE(size) \
120 	(((((size) - 1) << 1) & GENMASK(6, 1)) | PCIE_ATR_EN)
121 #define PCIE_ATR_ID(id)			((id) & GENMASK(3, 0))
122 #define PCIE_ATR_TYPE_MEM		PCIE_ATR_ID(0)
123 #define PCIE_ATR_TYPE_IO		PCIE_ATR_ID(1)
124 #define PCIE_ATR_TLP_TYPE(type)		(((type) << 16) & GENMASK(18, 16))
125 #define PCIE_ATR_TLP_TYPE_MEM		PCIE_ATR_TLP_TYPE(0)
126 #define PCIE_ATR_TLP_TYPE_IO		PCIE_ATR_TLP_TYPE(2)
127 
128 #define MAX_NUM_PHY_RESETS		3
129 
130 #define PCIE_MTK_RESET_TIME_US		10
131 
132 /* Time in ms needed to complete PCIe reset on EN7581 SoC */
133 #define PCIE_EN7581_RESET_TIME_MS	100
134 
135 struct mtk_gen3_pcie;
136 
137 #define PCIE_CONF_LINK2_CTL_STS		(PCIE_CFG_OFFSET_ADDR + 0xb0)
138 #define PCIE_CONF_LINK2_LCR2_LINK_SPEED	GENMASK(3, 0)
139 
140 enum mtk_gen3_pcie_flags {
141 	SKIP_PCIE_RSTB	= BIT(0), /* Skip PERST# assertion during device
142 				   * probing or suspend/resume phase to
143 				   * avoid hw bugs/issues.
144 				   */
145 };
146 
147 /**
148  * struct mtk_gen3_pcie_pdata - differentiate between host generations
149  * @power_up: pcie power_up callback
150  * @phy_resets: phy reset lines SoC data.
151  * @flags: pcie device flags.
152  */
153 struct mtk_gen3_pcie_pdata {
154 	int (*power_up)(struct mtk_gen3_pcie *pcie);
155 	struct {
156 		const char *id[MAX_NUM_PHY_RESETS];
157 		int num_resets;
158 	} phy_resets;
159 	u32 flags;
160 };
161 
162 /**
163  * struct mtk_msi_set - MSI information for each set
164  * @base: IO mapped register base
165  * @msg_addr: MSI message address
166  * @saved_irq_state: IRQ enable state saved at suspend time
167  */
168 struct mtk_msi_set {
169 	void __iomem *base;
170 	phys_addr_t msg_addr;
171 	u32 saved_irq_state;
172 };
173 
174 /**
175  * struct mtk_gen3_pcie - PCIe port information
176  * @dev: pointer to PCIe device
177  * @base: IO mapped register base
178  * @reg_base: physical register base
179  * @mac_reset: MAC reset control
180  * @phy_resets: PHY reset controllers
181  * @phy: PHY controller block
182  * @clks: PCIe clocks
183  * @num_clks: PCIe clocks count for this port
184  * @max_link_speed: Maximum link speed (PCIe Gen) for this port
185  * @num_lanes: Number of PCIe lanes for this port
186  * @irq: PCIe controller interrupt number
187  * @saved_irq_state: IRQ enable state saved at suspend time
188  * @irq_lock: lock protecting IRQ register access
189  * @intx_domain: legacy INTx IRQ domain
190  * @msi_domain: MSI IRQ domain
191  * @msi_bottom_domain: MSI IRQ bottom domain
192  * @msi_sets: MSI sets information
193  * @lock: lock protecting IRQ bit map
194  * @msi_irq_in_use: bit map for assigned MSI IRQ
195  * @soc: pointer to SoC-dependent operations
196  */
197 struct mtk_gen3_pcie {
198 	struct device *dev;
199 	void __iomem *base;
200 	phys_addr_t reg_base;
201 	struct reset_control *mac_reset;
202 	struct reset_control_bulk_data phy_resets[MAX_NUM_PHY_RESETS];
203 	struct phy *phy;
204 	struct clk_bulk_data *clks;
205 	int num_clks;
206 	u8 max_link_speed;
207 	u8 num_lanes;
208 
209 	int irq;
210 	u32 saved_irq_state;
211 	raw_spinlock_t irq_lock;
212 	struct irq_domain *intx_domain;
213 	struct irq_domain *msi_domain;
214 	struct irq_domain *msi_bottom_domain;
215 	struct mtk_msi_set msi_sets[PCIE_MSI_SET_NUM];
216 	struct mutex lock;
217 	DECLARE_BITMAP(msi_irq_in_use, PCIE_MSI_IRQS_NUM);
218 
219 	const struct mtk_gen3_pcie_pdata *soc;
220 };
221 
222 /* LTSSM state in PCIE_LTSSM_STATUS_REG bit[28:24] */
223 static const char *const ltssm_str[] = {
224 	"detect.quiet",			/* 0x00 */
225 	"detect.active",		/* 0x01 */
226 	"polling.active",		/* 0x02 */
227 	"polling.compliance",		/* 0x03 */
228 	"polling.configuration",	/* 0x04 */
229 	"config.linkwidthstart",	/* 0x05 */
230 	"config.linkwidthaccept",	/* 0x06 */
231 	"config.lanenumwait",		/* 0x07 */
232 	"config.lanenumaccept",		/* 0x08 */
233 	"config.complete",		/* 0x09 */
234 	"config.idle",			/* 0x0A */
235 	"recovery.receiverlock",	/* 0x0B */
236 	"recovery.equalization",	/* 0x0C */
237 	"recovery.speed",		/* 0x0D */
238 	"recovery.receiverconfig",	/* 0x0E */
239 	"recovery.idle",		/* 0x0F */
240 	"L0",				/* 0x10 */
241 	"L0s",				/* 0x11 */
242 	"L1.entry",			/* 0x12 */
243 	"L1.idle",			/* 0x13 */
244 	"L2.idle",			/* 0x14 */
245 	"L2.transmitwake",		/* 0x15 */
246 	"disable",			/* 0x16 */
247 	"loopback.entry",		/* 0x17 */
248 	"loopback.active",		/* 0x18 */
249 	"loopback.exit",		/* 0x19 */
250 	"hotreset",			/* 0x1A */
251 };
252 
253 /**
254  * mtk_pcie_config_tlp_header() - Configure a configuration TLP header
255  * @bus: PCI bus to query
256  * @devfn: device/function number
257  * @where: offset in config space
258  * @size: data size in TLP header
259  *
260  * Set byte enable field and device information in configuration TLP header.
261  */
mtk_pcie_config_tlp_header(struct pci_bus * bus,unsigned int devfn,int where,int size)262 static void mtk_pcie_config_tlp_header(struct pci_bus *bus, unsigned int devfn,
263 					int where, int size)
264 {
265 	struct mtk_gen3_pcie *pcie = bus->sysdata;
266 	int bytes;
267 	u32 val;
268 
269 	bytes = (GENMASK(size - 1, 0) & 0xf) << (where & 0x3);
270 
271 	val = PCIE_CFG_FORCE_BYTE_EN | PCIE_CFG_BYTE_EN(bytes) |
272 	      PCIE_CFG_HEADER(bus->number, devfn);
273 
274 	writel_relaxed(val, pcie->base + PCIE_CFGNUM_REG);
275 }
276 
mtk_pcie_map_bus(struct pci_bus * bus,unsigned int devfn,int where)277 static void __iomem *mtk_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
278 				      int where)
279 {
280 	struct mtk_gen3_pcie *pcie = bus->sysdata;
281 
282 	return pcie->base + PCIE_CFG_OFFSET_ADDR + where;
283 }
284 
mtk_pcie_config_read(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 * val)285 static int mtk_pcie_config_read(struct pci_bus *bus, unsigned int devfn,
286 				int where, int size, u32 *val)
287 {
288 	mtk_pcie_config_tlp_header(bus, devfn, where, size);
289 
290 	return pci_generic_config_read32(bus, devfn, where, size, val);
291 }
292 
mtk_pcie_config_write(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 val)293 static int mtk_pcie_config_write(struct pci_bus *bus, unsigned int devfn,
294 				 int where, int size, u32 val)
295 {
296 	mtk_pcie_config_tlp_header(bus, devfn, where, size);
297 
298 	if (size <= 2)
299 		val <<= (where & 0x3) * 8;
300 
301 	return pci_generic_config_write32(bus, devfn, where, 4, val);
302 }
303 
304 static struct pci_ops mtk_pcie_ops = {
305 	.map_bus = mtk_pcie_map_bus,
306 	.read  = mtk_pcie_config_read,
307 	.write = mtk_pcie_config_write,
308 };
309 
mtk_pcie_set_trans_table(struct mtk_gen3_pcie * pcie,resource_size_t cpu_addr,resource_size_t pci_addr,resource_size_t size,unsigned long type,int * num)310 static int mtk_pcie_set_trans_table(struct mtk_gen3_pcie *pcie,
311 				    resource_size_t cpu_addr,
312 				    resource_size_t pci_addr,
313 				    resource_size_t size,
314 				    unsigned long type, int *num)
315 {
316 	resource_size_t remaining = size;
317 	resource_size_t table_size;
318 	resource_size_t addr_align;
319 	const char *range_type;
320 	void __iomem *table;
321 	u32 val;
322 
323 	while (remaining && (*num < PCIE_MAX_TRANS_TABLES)) {
324 		/* Table size needs to be a power of 2 */
325 		table_size = BIT(fls(remaining) - 1);
326 
327 		if (cpu_addr > 0) {
328 			addr_align = BIT(ffs(cpu_addr) - 1);
329 			table_size = min(table_size, addr_align);
330 		}
331 
332 		/* Minimum size of translate table is 4KiB */
333 		if (table_size < 0x1000) {
334 			dev_err(pcie->dev, "illegal table size %#llx\n",
335 				(unsigned long long)table_size);
336 			return -EINVAL;
337 		}
338 
339 		table = pcie->base + PCIE_TRANS_TABLE_BASE_REG + *num * PCIE_ATR_TLB_SET_OFFSET;
340 		writel_relaxed(lower_32_bits(cpu_addr) | PCIE_ATR_SIZE(fls(table_size) - 1), table);
341 		writel_relaxed(upper_32_bits(cpu_addr), table + PCIE_ATR_SRC_ADDR_MSB_OFFSET);
342 		writel_relaxed(lower_32_bits(pci_addr), table + PCIE_ATR_TRSL_ADDR_LSB_OFFSET);
343 		writel_relaxed(upper_32_bits(pci_addr), table + PCIE_ATR_TRSL_ADDR_MSB_OFFSET);
344 
345 		if (type == IORESOURCE_IO) {
346 			val = PCIE_ATR_TYPE_IO | PCIE_ATR_TLP_TYPE_IO;
347 			range_type = "IO";
348 		} else {
349 			val = PCIE_ATR_TYPE_MEM | PCIE_ATR_TLP_TYPE_MEM;
350 			range_type = "MEM";
351 		}
352 
353 		writel_relaxed(val, table + PCIE_ATR_TRSL_PARAM_OFFSET);
354 
355 		dev_dbg(pcie->dev, "set %s trans window[%d]: cpu_addr = %#llx, pci_addr = %#llx, size = %#llx\n",
356 			range_type, *num, (unsigned long long)cpu_addr,
357 			(unsigned long long)pci_addr,
358 			(unsigned long long)table_size);
359 
360 		cpu_addr += table_size;
361 		pci_addr += table_size;
362 		remaining -= table_size;
363 		(*num)++;
364 	}
365 
366 	if (remaining)
367 		dev_warn(pcie->dev, "not enough translate table for addr: %#llx, limited to [%d]\n",
368 			 (unsigned long long)cpu_addr, PCIE_MAX_TRANS_TABLES);
369 
370 	return 0;
371 }
372 
mtk_pcie_enable_msi(struct mtk_gen3_pcie * pcie)373 static void mtk_pcie_enable_msi(struct mtk_gen3_pcie *pcie)
374 {
375 	int i;
376 	u32 val;
377 
378 	for (i = 0; i < PCIE_MSI_SET_NUM; i++) {
379 		struct mtk_msi_set *msi_set = &pcie->msi_sets[i];
380 
381 		msi_set->base = pcie->base + PCIE_MSI_SET_BASE_REG +
382 				i * PCIE_MSI_SET_OFFSET;
383 		msi_set->msg_addr = pcie->reg_base + PCIE_MSI_SET_BASE_REG +
384 				    i * PCIE_MSI_SET_OFFSET;
385 
386 		/* Configure the MSI capture address */
387 		writel_relaxed(lower_32_bits(msi_set->msg_addr), msi_set->base);
388 		writel_relaxed(upper_32_bits(msi_set->msg_addr),
389 			       pcie->base + PCIE_MSI_SET_ADDR_HI_BASE +
390 			       i * PCIE_MSI_SET_ADDR_HI_OFFSET);
391 	}
392 
393 	val = readl_relaxed(pcie->base + PCIE_MSI_SET_ENABLE_REG);
394 	val |= PCIE_MSI_SET_ENABLE;
395 	writel_relaxed(val, pcie->base + PCIE_MSI_SET_ENABLE_REG);
396 
397 	val = readl_relaxed(pcie->base + PCIE_INT_ENABLE_REG);
398 	val |= PCIE_MSI_ENABLE;
399 	writel_relaxed(val, pcie->base + PCIE_INT_ENABLE_REG);
400 }
401 
mtk_pcie_startup_port(struct mtk_gen3_pcie * pcie)402 static int mtk_pcie_startup_port(struct mtk_gen3_pcie *pcie)
403 {
404 	struct resource_entry *entry;
405 	struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
406 	unsigned int table_index = 0;
407 	int err;
408 	u32 val;
409 
410 	/* Set as RC mode and set controller PCIe Gen speed restriction, if any */
411 	val = readl_relaxed(pcie->base + PCIE_SETTING_REG);
412 	val |= PCIE_RC_MODE;
413 	if (pcie->max_link_speed) {
414 		val &= ~PCIE_SETTING_GEN_SUPPORT;
415 
416 		/* Can enable link speed support only from Gen2 onwards */
417 		if (pcie->max_link_speed >= 2)
418 			val |= FIELD_PREP(PCIE_SETTING_GEN_SUPPORT,
419 					  GENMASK(pcie->max_link_speed - 2, 0));
420 	}
421 	if (pcie->num_lanes) {
422 		val &= ~PCIE_SETTING_LINK_WIDTH;
423 
424 		/* Zero means one lane, each bit activates x2/x4/x8/x16 */
425 		if (pcie->num_lanes > 1)
426 			val |= FIELD_PREP(PCIE_SETTING_LINK_WIDTH,
427 					  GENMASK(fls(pcie->num_lanes >> 2), 0));
428 	}
429 	writel_relaxed(val, pcie->base + PCIE_SETTING_REG);
430 
431 	/* Set Link Control 2 (LNKCTL2) speed restriction, if any */
432 	if (pcie->max_link_speed) {
433 		val = readl_relaxed(pcie->base + PCIE_CONF_LINK2_CTL_STS);
434 		val &= ~PCIE_CONF_LINK2_LCR2_LINK_SPEED;
435 		val |= FIELD_PREP(PCIE_CONF_LINK2_LCR2_LINK_SPEED, pcie->max_link_speed);
436 		writel_relaxed(val, pcie->base + PCIE_CONF_LINK2_CTL_STS);
437 	}
438 
439 	/* Set class code */
440 	val = readl_relaxed(pcie->base + PCIE_PCI_IDS_1);
441 	val &= ~GENMASK(31, 8);
442 	val |= PCI_CLASS(PCI_CLASS_BRIDGE_PCI_NORMAL);
443 	writel_relaxed(val, pcie->base + PCIE_PCI_IDS_1);
444 
445 	/* Mask all INTx interrupts */
446 	val = readl_relaxed(pcie->base + PCIE_INT_ENABLE_REG);
447 	val &= ~PCIE_INTX_ENABLE;
448 	writel_relaxed(val, pcie->base + PCIE_INT_ENABLE_REG);
449 
450 	/* Disable DVFSRC voltage request */
451 	val = readl_relaxed(pcie->base + PCIE_MISC_CTRL_REG);
452 	val |= PCIE_DISABLE_DVFSRC_VLT_REQ;
453 	writel_relaxed(val, pcie->base + PCIE_MISC_CTRL_REG);
454 
455 	/*
456 	 * Airoha EN7581 has a hw bug asserting/releasing PCIE_PE_RSTB signal
457 	 * causing occasional PCIe link down. In order to overcome the issue,
458 	 * PCIE_RSTB signals are not asserted/released at this stage and the
459 	 * PCIe block is reset using en7523_reset_assert() and
460 	 * en7581_pci_enable().
461 	 */
462 	if (!(pcie->soc->flags & SKIP_PCIE_RSTB)) {
463 		/* Assert all reset signals */
464 		val = readl_relaxed(pcie->base + PCIE_RST_CTRL_REG);
465 		val |= PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB |
466 		       PCIE_PE_RSTB;
467 		writel_relaxed(val, pcie->base + PCIE_RST_CTRL_REG);
468 
469 		/*
470 		 * Described in PCIe CEM specification revision 6.0.
471 		 *
472 		 * The deassertion of PERST# should be delayed 100ms (TPVPERL)
473 		 * for the power and clock to become stable.
474 		 */
475 		msleep(PCIE_T_PVPERL_MS);
476 
477 		/* De-assert reset signals */
478 		val &= ~(PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB |
479 			 PCIE_PE_RSTB);
480 		writel_relaxed(val, pcie->base + PCIE_RST_CTRL_REG);
481 	}
482 
483 	/* Check if the link is up or not */
484 	err = readl_poll_timeout(pcie->base + PCIE_LINK_STATUS_REG, val,
485 				 !!(val & PCIE_PORT_LINKUP), 20,
486 				 PCI_PM_D3COLD_WAIT * USEC_PER_MSEC);
487 	if (err) {
488 		const char *ltssm_state;
489 		int ltssm_index;
490 
491 		val = readl_relaxed(pcie->base + PCIE_LTSSM_STATUS_REG);
492 		ltssm_index = PCIE_LTSSM_STATE(val);
493 		ltssm_state = ltssm_index >= ARRAY_SIZE(ltssm_str) ?
494 			      "Unknown state" : ltssm_str[ltssm_index];
495 		dev_err(pcie->dev,
496 			"PCIe link down, current LTSSM state: %s (%#x)\n",
497 			ltssm_state, val);
498 		return err;
499 	}
500 
501 	mtk_pcie_enable_msi(pcie);
502 
503 	/* Set PCIe translation windows */
504 	resource_list_for_each_entry(entry, &host->windows) {
505 		struct resource *res = entry->res;
506 		unsigned long type = resource_type(res);
507 		resource_size_t cpu_addr;
508 		resource_size_t pci_addr;
509 		resource_size_t size;
510 
511 		if (type == IORESOURCE_IO)
512 			cpu_addr = pci_pio_to_address(res->start);
513 		else if (type == IORESOURCE_MEM)
514 			cpu_addr = res->start;
515 		else
516 			continue;
517 
518 		pci_addr = res->start - entry->offset;
519 		size = resource_size(res);
520 		err = mtk_pcie_set_trans_table(pcie, cpu_addr, pci_addr, size,
521 					       type, &table_index);
522 		if (err)
523 			return err;
524 	}
525 
526 	return 0;
527 }
528 
mtk_pcie_msi_irq_mask(struct irq_data * data)529 static void mtk_pcie_msi_irq_mask(struct irq_data *data)
530 {
531 	pci_msi_mask_irq(data);
532 	irq_chip_mask_parent(data);
533 }
534 
mtk_pcie_msi_irq_unmask(struct irq_data * data)535 static void mtk_pcie_msi_irq_unmask(struct irq_data *data)
536 {
537 	pci_msi_unmask_irq(data);
538 	irq_chip_unmask_parent(data);
539 }
540 
541 static struct irq_chip mtk_msi_irq_chip = {
542 	.irq_ack = irq_chip_ack_parent,
543 	.irq_mask = mtk_pcie_msi_irq_mask,
544 	.irq_unmask = mtk_pcie_msi_irq_unmask,
545 	.name = "MSI",
546 };
547 
548 static struct msi_domain_info mtk_msi_domain_info = {
549 	.flags	= MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
550 		  MSI_FLAG_NO_AFFINITY | MSI_FLAG_PCI_MSIX |
551 		  MSI_FLAG_MULTI_PCI_MSI,
552 	.chip	= &mtk_msi_irq_chip,
553 };
554 
mtk_compose_msi_msg(struct irq_data * data,struct msi_msg * msg)555 static void mtk_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
556 {
557 	struct mtk_msi_set *msi_set = irq_data_get_irq_chip_data(data);
558 	struct mtk_gen3_pcie *pcie = data->domain->host_data;
559 	unsigned long hwirq;
560 
561 	hwirq =	data->hwirq % PCIE_MSI_IRQS_PER_SET;
562 
563 	msg->address_hi = upper_32_bits(msi_set->msg_addr);
564 	msg->address_lo = lower_32_bits(msi_set->msg_addr);
565 	msg->data = hwirq;
566 	dev_dbg(pcie->dev, "msi#%#lx address_hi %#x address_lo %#x data %d\n",
567 		hwirq, msg->address_hi, msg->address_lo, msg->data);
568 }
569 
mtk_msi_bottom_irq_ack(struct irq_data * data)570 static void mtk_msi_bottom_irq_ack(struct irq_data *data)
571 {
572 	struct mtk_msi_set *msi_set = irq_data_get_irq_chip_data(data);
573 	unsigned long hwirq;
574 
575 	hwirq =	data->hwirq % PCIE_MSI_IRQS_PER_SET;
576 
577 	writel_relaxed(BIT(hwirq), msi_set->base + PCIE_MSI_SET_STATUS_OFFSET);
578 }
579 
mtk_msi_bottom_irq_mask(struct irq_data * data)580 static void mtk_msi_bottom_irq_mask(struct irq_data *data)
581 {
582 	struct mtk_msi_set *msi_set = irq_data_get_irq_chip_data(data);
583 	struct mtk_gen3_pcie *pcie = data->domain->host_data;
584 	unsigned long hwirq, flags;
585 	u32 val;
586 
587 	hwirq =	data->hwirq % PCIE_MSI_IRQS_PER_SET;
588 
589 	raw_spin_lock_irqsave(&pcie->irq_lock, flags);
590 	val = readl_relaxed(msi_set->base + PCIE_MSI_SET_ENABLE_OFFSET);
591 	val &= ~BIT(hwirq);
592 	writel_relaxed(val, msi_set->base + PCIE_MSI_SET_ENABLE_OFFSET);
593 	raw_spin_unlock_irqrestore(&pcie->irq_lock, flags);
594 }
595 
mtk_msi_bottom_irq_unmask(struct irq_data * data)596 static void mtk_msi_bottom_irq_unmask(struct irq_data *data)
597 {
598 	struct mtk_msi_set *msi_set = irq_data_get_irq_chip_data(data);
599 	struct mtk_gen3_pcie *pcie = data->domain->host_data;
600 	unsigned long hwirq, flags;
601 	u32 val;
602 
603 	hwirq =	data->hwirq % PCIE_MSI_IRQS_PER_SET;
604 
605 	raw_spin_lock_irqsave(&pcie->irq_lock, flags);
606 	val = readl_relaxed(msi_set->base + PCIE_MSI_SET_ENABLE_OFFSET);
607 	val |= BIT(hwirq);
608 	writel_relaxed(val, msi_set->base + PCIE_MSI_SET_ENABLE_OFFSET);
609 	raw_spin_unlock_irqrestore(&pcie->irq_lock, flags);
610 }
611 
612 static struct irq_chip mtk_msi_bottom_irq_chip = {
613 	.irq_ack		= mtk_msi_bottom_irq_ack,
614 	.irq_mask		= mtk_msi_bottom_irq_mask,
615 	.irq_unmask		= mtk_msi_bottom_irq_unmask,
616 	.irq_compose_msi_msg	= mtk_compose_msi_msg,
617 	.name			= "MSI",
618 };
619 
mtk_msi_bottom_domain_alloc(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs,void * arg)620 static int mtk_msi_bottom_domain_alloc(struct irq_domain *domain,
621 				       unsigned int virq, unsigned int nr_irqs,
622 				       void *arg)
623 {
624 	struct mtk_gen3_pcie *pcie = domain->host_data;
625 	struct mtk_msi_set *msi_set;
626 	int i, hwirq, set_idx;
627 
628 	mutex_lock(&pcie->lock);
629 
630 	hwirq = bitmap_find_free_region(pcie->msi_irq_in_use, PCIE_MSI_IRQS_NUM,
631 					order_base_2(nr_irqs));
632 
633 	mutex_unlock(&pcie->lock);
634 
635 	if (hwirq < 0)
636 		return -ENOSPC;
637 
638 	set_idx = hwirq / PCIE_MSI_IRQS_PER_SET;
639 	msi_set = &pcie->msi_sets[set_idx];
640 
641 	for (i = 0; i < nr_irqs; i++)
642 		irq_domain_set_info(domain, virq + i, hwirq + i,
643 				    &mtk_msi_bottom_irq_chip, msi_set,
644 				    handle_edge_irq, NULL, NULL);
645 
646 	return 0;
647 }
648 
mtk_msi_bottom_domain_free(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs)649 static void mtk_msi_bottom_domain_free(struct irq_domain *domain,
650 				       unsigned int virq, unsigned int nr_irqs)
651 {
652 	struct mtk_gen3_pcie *pcie = domain->host_data;
653 	struct irq_data *data = irq_domain_get_irq_data(domain, virq);
654 
655 	mutex_lock(&pcie->lock);
656 
657 	bitmap_release_region(pcie->msi_irq_in_use, data->hwirq,
658 			      order_base_2(nr_irqs));
659 
660 	mutex_unlock(&pcie->lock);
661 
662 	irq_domain_free_irqs_common(domain, virq, nr_irqs);
663 }
664 
665 static const struct irq_domain_ops mtk_msi_bottom_domain_ops = {
666 	.alloc = mtk_msi_bottom_domain_alloc,
667 	.free = mtk_msi_bottom_domain_free,
668 };
669 
mtk_intx_mask(struct irq_data * data)670 static void mtk_intx_mask(struct irq_data *data)
671 {
672 	struct mtk_gen3_pcie *pcie = irq_data_get_irq_chip_data(data);
673 	unsigned long flags;
674 	u32 val;
675 
676 	raw_spin_lock_irqsave(&pcie->irq_lock, flags);
677 	val = readl_relaxed(pcie->base + PCIE_INT_ENABLE_REG);
678 	val &= ~BIT(data->hwirq + PCIE_INTX_SHIFT);
679 	writel_relaxed(val, pcie->base + PCIE_INT_ENABLE_REG);
680 	raw_spin_unlock_irqrestore(&pcie->irq_lock, flags);
681 }
682 
mtk_intx_unmask(struct irq_data * data)683 static void mtk_intx_unmask(struct irq_data *data)
684 {
685 	struct mtk_gen3_pcie *pcie = irq_data_get_irq_chip_data(data);
686 	unsigned long flags;
687 	u32 val;
688 
689 	raw_spin_lock_irqsave(&pcie->irq_lock, flags);
690 	val = readl_relaxed(pcie->base + PCIE_INT_ENABLE_REG);
691 	val |= BIT(data->hwirq + PCIE_INTX_SHIFT);
692 	writel_relaxed(val, pcie->base + PCIE_INT_ENABLE_REG);
693 	raw_spin_unlock_irqrestore(&pcie->irq_lock, flags);
694 }
695 
696 /**
697  * mtk_intx_eoi() - Clear INTx IRQ status at the end of interrupt
698  * @data: pointer to chip specific data
699  *
700  * As an emulated level IRQ, its interrupt status will remain
701  * until the corresponding de-assert message is received; hence that
702  * the status can only be cleared when the interrupt has been serviced.
703  */
mtk_intx_eoi(struct irq_data * data)704 static void mtk_intx_eoi(struct irq_data *data)
705 {
706 	struct mtk_gen3_pcie *pcie = irq_data_get_irq_chip_data(data);
707 	unsigned long hwirq;
708 
709 	hwirq = data->hwirq + PCIE_INTX_SHIFT;
710 	writel_relaxed(BIT(hwirq), pcie->base + PCIE_INT_STATUS_REG);
711 }
712 
713 static struct irq_chip mtk_intx_irq_chip = {
714 	.irq_mask		= mtk_intx_mask,
715 	.irq_unmask		= mtk_intx_unmask,
716 	.irq_eoi		= mtk_intx_eoi,
717 	.name			= "INTx",
718 };
719 
mtk_pcie_intx_map(struct irq_domain * domain,unsigned int irq,irq_hw_number_t hwirq)720 static int mtk_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
721 			     irq_hw_number_t hwirq)
722 {
723 	irq_set_chip_data(irq, domain->host_data);
724 	irq_set_chip_and_handler_name(irq, &mtk_intx_irq_chip,
725 				      handle_fasteoi_irq, "INTx");
726 	return 0;
727 }
728 
729 static const struct irq_domain_ops intx_domain_ops = {
730 	.map = mtk_pcie_intx_map,
731 };
732 
mtk_pcie_init_irq_domains(struct mtk_gen3_pcie * pcie)733 static int mtk_pcie_init_irq_domains(struct mtk_gen3_pcie *pcie)
734 {
735 	struct device *dev = pcie->dev;
736 	struct device_node *intc_node, *node = dev->of_node;
737 	int ret;
738 
739 	raw_spin_lock_init(&pcie->irq_lock);
740 
741 	/* Setup INTx */
742 	intc_node = of_get_child_by_name(node, "interrupt-controller");
743 	if (!intc_node) {
744 		dev_err(dev, "missing interrupt-controller node\n");
745 		return -ENODEV;
746 	}
747 
748 	pcie->intx_domain = irq_domain_add_linear(intc_node, PCI_NUM_INTX,
749 						  &intx_domain_ops, pcie);
750 	if (!pcie->intx_domain) {
751 		dev_err(dev, "failed to create INTx IRQ domain\n");
752 		ret = -ENODEV;
753 		goto out_put_node;
754 	}
755 
756 	/* Setup MSI */
757 	mutex_init(&pcie->lock);
758 
759 	pcie->msi_bottom_domain = irq_domain_add_linear(node, PCIE_MSI_IRQS_NUM,
760 				  &mtk_msi_bottom_domain_ops, pcie);
761 	if (!pcie->msi_bottom_domain) {
762 		dev_err(dev, "failed to create MSI bottom domain\n");
763 		ret = -ENODEV;
764 		goto err_msi_bottom_domain;
765 	}
766 
767 	pcie->msi_domain = pci_msi_create_irq_domain(dev->fwnode,
768 						     &mtk_msi_domain_info,
769 						     pcie->msi_bottom_domain);
770 	if (!pcie->msi_domain) {
771 		dev_err(dev, "failed to create MSI domain\n");
772 		ret = -ENODEV;
773 		goto err_msi_domain;
774 	}
775 
776 	of_node_put(intc_node);
777 	return 0;
778 
779 err_msi_domain:
780 	irq_domain_remove(pcie->msi_bottom_domain);
781 err_msi_bottom_domain:
782 	irq_domain_remove(pcie->intx_domain);
783 out_put_node:
784 	of_node_put(intc_node);
785 	return ret;
786 }
787 
mtk_pcie_irq_teardown(struct mtk_gen3_pcie * pcie)788 static void mtk_pcie_irq_teardown(struct mtk_gen3_pcie *pcie)
789 {
790 	irq_set_chained_handler_and_data(pcie->irq, NULL, NULL);
791 
792 	if (pcie->intx_domain)
793 		irq_domain_remove(pcie->intx_domain);
794 
795 	if (pcie->msi_domain)
796 		irq_domain_remove(pcie->msi_domain);
797 
798 	if (pcie->msi_bottom_domain)
799 		irq_domain_remove(pcie->msi_bottom_domain);
800 
801 	irq_dispose_mapping(pcie->irq);
802 }
803 
mtk_pcie_msi_handler(struct mtk_gen3_pcie * pcie,int set_idx)804 static void mtk_pcie_msi_handler(struct mtk_gen3_pcie *pcie, int set_idx)
805 {
806 	struct mtk_msi_set *msi_set = &pcie->msi_sets[set_idx];
807 	unsigned long msi_enable, msi_status;
808 	irq_hw_number_t bit, hwirq;
809 
810 	msi_enable = readl_relaxed(msi_set->base + PCIE_MSI_SET_ENABLE_OFFSET);
811 
812 	do {
813 		msi_status = readl_relaxed(msi_set->base +
814 					   PCIE_MSI_SET_STATUS_OFFSET);
815 		msi_status &= msi_enable;
816 		if (!msi_status)
817 			break;
818 
819 		for_each_set_bit(bit, &msi_status, PCIE_MSI_IRQS_PER_SET) {
820 			hwirq = bit + set_idx * PCIE_MSI_IRQS_PER_SET;
821 			generic_handle_domain_irq(pcie->msi_bottom_domain, hwirq);
822 		}
823 	} while (true);
824 }
825 
mtk_pcie_irq_handler(struct irq_desc * desc)826 static void mtk_pcie_irq_handler(struct irq_desc *desc)
827 {
828 	struct mtk_gen3_pcie *pcie = irq_desc_get_handler_data(desc);
829 	struct irq_chip *irqchip = irq_desc_get_chip(desc);
830 	unsigned long status;
831 	irq_hw_number_t irq_bit = PCIE_INTX_SHIFT;
832 
833 	chained_irq_enter(irqchip, desc);
834 
835 	status = readl_relaxed(pcie->base + PCIE_INT_STATUS_REG);
836 	for_each_set_bit_from(irq_bit, &status, PCI_NUM_INTX +
837 			      PCIE_INTX_SHIFT)
838 		generic_handle_domain_irq(pcie->intx_domain,
839 					  irq_bit - PCIE_INTX_SHIFT);
840 
841 	irq_bit = PCIE_MSI_SHIFT;
842 	for_each_set_bit_from(irq_bit, &status, PCIE_MSI_SET_NUM +
843 			      PCIE_MSI_SHIFT) {
844 		mtk_pcie_msi_handler(pcie, irq_bit - PCIE_MSI_SHIFT);
845 
846 		writel_relaxed(BIT(irq_bit), pcie->base + PCIE_INT_STATUS_REG);
847 	}
848 
849 	chained_irq_exit(irqchip, desc);
850 }
851 
mtk_pcie_setup_irq(struct mtk_gen3_pcie * pcie)852 static int mtk_pcie_setup_irq(struct mtk_gen3_pcie *pcie)
853 {
854 	struct device *dev = pcie->dev;
855 	struct platform_device *pdev = to_platform_device(dev);
856 	int err;
857 
858 	err = mtk_pcie_init_irq_domains(pcie);
859 	if (err)
860 		return err;
861 
862 	pcie->irq = platform_get_irq(pdev, 0);
863 	if (pcie->irq < 0)
864 		return pcie->irq;
865 
866 	irq_set_chained_handler_and_data(pcie->irq, mtk_pcie_irq_handler, pcie);
867 
868 	return 0;
869 }
870 
mtk_pcie_parse_port(struct mtk_gen3_pcie * pcie)871 static int mtk_pcie_parse_port(struct mtk_gen3_pcie *pcie)
872 {
873 	int i, ret, num_resets = pcie->soc->phy_resets.num_resets;
874 	struct device *dev = pcie->dev;
875 	struct platform_device *pdev = to_platform_device(dev);
876 	struct resource *regs;
877 	u32 num_lanes;
878 
879 	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pcie-mac");
880 	if (!regs)
881 		return -EINVAL;
882 	pcie->base = devm_ioremap_resource(dev, regs);
883 	if (IS_ERR(pcie->base)) {
884 		dev_err(dev, "failed to map register base\n");
885 		return PTR_ERR(pcie->base);
886 	}
887 
888 	pcie->reg_base = regs->start;
889 
890 	for (i = 0; i < num_resets; i++)
891 		pcie->phy_resets[i].id = pcie->soc->phy_resets.id[i];
892 
893 	ret = devm_reset_control_bulk_get_optional_shared(dev, num_resets,
894 							  pcie->phy_resets);
895 	if (ret) {
896 		dev_err(dev, "failed to get PHY bulk reset\n");
897 		return ret;
898 	}
899 
900 	pcie->mac_reset = devm_reset_control_get_optional_exclusive(dev, "mac");
901 	if (IS_ERR(pcie->mac_reset)) {
902 		ret = PTR_ERR(pcie->mac_reset);
903 		if (ret != -EPROBE_DEFER)
904 			dev_err(dev, "failed to get MAC reset\n");
905 
906 		return ret;
907 	}
908 
909 	pcie->phy = devm_phy_optional_get(dev, "pcie-phy");
910 	if (IS_ERR(pcie->phy)) {
911 		ret = PTR_ERR(pcie->phy);
912 		if (ret != -EPROBE_DEFER)
913 			dev_err(dev, "failed to get PHY\n");
914 
915 		return ret;
916 	}
917 
918 	pcie->num_clks = devm_clk_bulk_get_all(dev, &pcie->clks);
919 	if (pcie->num_clks < 0) {
920 		dev_err(dev, "failed to get clocks\n");
921 		return pcie->num_clks;
922 	}
923 
924 	ret = of_property_read_u32(dev->of_node, "num-lanes", &num_lanes);
925 	if (ret == 0) {
926 		if (num_lanes == 0 || num_lanes > 16 ||
927 		    (num_lanes != 1 && num_lanes % 2))
928 			dev_warn(dev, "invalid num-lanes, using controller defaults\n");
929 		else
930 			pcie->num_lanes = num_lanes;
931 	}
932 
933 	return 0;
934 }
935 
mtk_pcie_en7581_power_up(struct mtk_gen3_pcie * pcie)936 static int mtk_pcie_en7581_power_up(struct mtk_gen3_pcie *pcie)
937 {
938 	struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
939 	struct device *dev = pcie->dev;
940 	struct resource_entry *entry;
941 	struct regmap *pbus_regmap;
942 	u32 val, args[2], size;
943 	resource_size_t addr;
944 	int err;
945 
946 	/*
947 	 * The controller may have been left out of reset by the bootloader
948 	 * so make sure that we get a clean start by asserting resets here.
949 	 */
950 	reset_control_bulk_assert(pcie->soc->phy_resets.num_resets,
951 				  pcie->phy_resets);
952 
953 	/* Wait for the time needed to complete the reset lines assert. */
954 	msleep(PCIE_EN7581_RESET_TIME_MS);
955 
956 	/*
957 	 * Configure PBus base address and base address mask to allow the
958 	 * hw to detect if a given address is accessible on PCIe controller.
959 	 */
960 	pbus_regmap = syscon_regmap_lookup_by_phandle_args(dev->of_node,
961 							   "mediatek,pbus-csr",
962 							   ARRAY_SIZE(args),
963 							   args);
964 	if (IS_ERR(pbus_regmap))
965 		return PTR_ERR(pbus_regmap);
966 
967 	entry = resource_list_first_type(&host->windows, IORESOURCE_MEM);
968 	if (!entry)
969 		return -ENODEV;
970 
971 	addr = entry->res->start - entry->offset;
972 	regmap_write(pbus_regmap, args[0], lower_32_bits(addr));
973 	size = lower_32_bits(resource_size(entry->res));
974 	regmap_write(pbus_regmap, args[1], GENMASK(31, __fls(size)));
975 
976 	/*
977 	 * Unlike the other MediaTek Gen3 controllers, the Airoha EN7581
978 	 * requires PHY initialization and power-on before PHY reset deassert.
979 	 */
980 	err = phy_init(pcie->phy);
981 	if (err) {
982 		dev_err(dev, "failed to initialize PHY\n");
983 		return err;
984 	}
985 
986 	err = phy_power_on(pcie->phy);
987 	if (err) {
988 		dev_err(dev, "failed to power on PHY\n");
989 		goto err_phy_on;
990 	}
991 
992 	err = reset_control_bulk_deassert(pcie->soc->phy_resets.num_resets,
993 					  pcie->phy_resets);
994 	if (err) {
995 		dev_err(dev, "failed to deassert PHYs\n");
996 		goto err_phy_deassert;
997 	}
998 
999 	/*
1000 	 * Wait for the time needed to complete the bulk de-assert above.
1001 	 * This time is specific for EN7581 SoC.
1002 	 */
1003 	msleep(PCIE_EN7581_RESET_TIME_MS);
1004 
1005 	pm_runtime_enable(dev);
1006 	pm_runtime_get_sync(dev);
1007 
1008 	val = FIELD_PREP(PCIE_VAL_LN0_DOWNSTREAM, 0x47) |
1009 	      FIELD_PREP(PCIE_VAL_LN1_DOWNSTREAM, 0x47) |
1010 	      FIELD_PREP(PCIE_VAL_LN0_UPSTREAM, 0x41) |
1011 	      FIELD_PREP(PCIE_VAL_LN1_UPSTREAM, 0x41);
1012 	writel_relaxed(val, pcie->base + PCIE_EQ_PRESET_01_REG);
1013 
1014 	val = PCIE_K_PHYPARAM_QUERY | PCIE_K_QUERY_TIMEOUT |
1015 	      FIELD_PREP(PCIE_K_PRESET_TO_USE_16G, 0x80) |
1016 	      FIELD_PREP(PCIE_K_PRESET_TO_USE, 0x2) |
1017 	      FIELD_PREP(PCIE_K_FINETUNE_MAX, 0xf);
1018 	writel_relaxed(val, pcie->base + PCIE_PIPE4_PIE8_REG);
1019 
1020 	err = clk_bulk_prepare_enable(pcie->num_clks, pcie->clks);
1021 	if (err) {
1022 		dev_err(dev, "failed to prepare clock\n");
1023 		goto err_clk_prepare_enable;
1024 	}
1025 
1026 	/*
1027 	 * Airoha EN7581 performs PCIe reset via clk callbacks since it has a
1028 	 * hw issue with PCIE_PE_RSTB signal. Add wait for the time needed to
1029 	 * complete the PCIe reset.
1030 	 */
1031 	msleep(PCIE_T_PVPERL_MS);
1032 
1033 	return 0;
1034 
1035 err_clk_prepare_enable:
1036 	pm_runtime_put_sync(dev);
1037 	pm_runtime_disable(dev);
1038 	reset_control_bulk_assert(pcie->soc->phy_resets.num_resets,
1039 				  pcie->phy_resets);
1040 err_phy_deassert:
1041 	phy_power_off(pcie->phy);
1042 err_phy_on:
1043 	phy_exit(pcie->phy);
1044 
1045 	return err;
1046 }
1047 
mtk_pcie_power_up(struct mtk_gen3_pcie * pcie)1048 static int mtk_pcie_power_up(struct mtk_gen3_pcie *pcie)
1049 {
1050 	struct device *dev = pcie->dev;
1051 	int err;
1052 
1053 	/*
1054 	 * The controller may have been left out of reset by the bootloader
1055 	 * so make sure that we get a clean start by asserting resets here.
1056 	 */
1057 	reset_control_bulk_assert(pcie->soc->phy_resets.num_resets,
1058 				  pcie->phy_resets);
1059 	reset_control_assert(pcie->mac_reset);
1060 	usleep_range(PCIE_MTK_RESET_TIME_US, 2 * PCIE_MTK_RESET_TIME_US);
1061 
1062 	/* PHY power on and enable pipe clock */
1063 	err = reset_control_bulk_deassert(pcie->soc->phy_resets.num_resets,
1064 					  pcie->phy_resets);
1065 	if (err) {
1066 		dev_err(dev, "failed to deassert PHYs\n");
1067 		return err;
1068 	}
1069 
1070 	err = phy_init(pcie->phy);
1071 	if (err) {
1072 		dev_err(dev, "failed to initialize PHY\n");
1073 		goto err_phy_init;
1074 	}
1075 
1076 	err = phy_power_on(pcie->phy);
1077 	if (err) {
1078 		dev_err(dev, "failed to power on PHY\n");
1079 		goto err_phy_on;
1080 	}
1081 
1082 	/* MAC power on and enable transaction layer clocks */
1083 	reset_control_deassert(pcie->mac_reset);
1084 
1085 	pm_runtime_enable(dev);
1086 	pm_runtime_get_sync(dev);
1087 
1088 	err = clk_bulk_prepare_enable(pcie->num_clks, pcie->clks);
1089 	if (err) {
1090 		dev_err(dev, "failed to enable clocks\n");
1091 		goto err_clk_init;
1092 	}
1093 
1094 	return 0;
1095 
1096 err_clk_init:
1097 	pm_runtime_put_sync(dev);
1098 	pm_runtime_disable(dev);
1099 	reset_control_assert(pcie->mac_reset);
1100 	phy_power_off(pcie->phy);
1101 err_phy_on:
1102 	phy_exit(pcie->phy);
1103 err_phy_init:
1104 	reset_control_bulk_assert(pcie->soc->phy_resets.num_resets,
1105 				  pcie->phy_resets);
1106 
1107 	return err;
1108 }
1109 
mtk_pcie_power_down(struct mtk_gen3_pcie * pcie)1110 static void mtk_pcie_power_down(struct mtk_gen3_pcie *pcie)
1111 {
1112 	clk_bulk_disable_unprepare(pcie->num_clks, pcie->clks);
1113 
1114 	pm_runtime_put_sync(pcie->dev);
1115 	pm_runtime_disable(pcie->dev);
1116 	reset_control_assert(pcie->mac_reset);
1117 
1118 	phy_power_off(pcie->phy);
1119 	phy_exit(pcie->phy);
1120 	reset_control_bulk_assert(pcie->soc->phy_resets.num_resets,
1121 				  pcie->phy_resets);
1122 }
1123 
mtk_pcie_get_controller_max_link_speed(struct mtk_gen3_pcie * pcie)1124 static int mtk_pcie_get_controller_max_link_speed(struct mtk_gen3_pcie *pcie)
1125 {
1126 	u32 val;
1127 	int ret;
1128 
1129 	val = readl_relaxed(pcie->base + PCIE_BASE_CFG_REG);
1130 	val = FIELD_GET(PCIE_BASE_CFG_SPEED, val);
1131 	ret = fls(val);
1132 
1133 	return ret > 0 ? ret : -EINVAL;
1134 }
1135 
mtk_pcie_setup(struct mtk_gen3_pcie * pcie)1136 static int mtk_pcie_setup(struct mtk_gen3_pcie *pcie)
1137 {
1138 	int err, max_speed;
1139 
1140 	err = mtk_pcie_parse_port(pcie);
1141 	if (err)
1142 		return err;
1143 
1144 	/*
1145 	 * Deassert the line in order to avoid unbalance in deassert_count
1146 	 * counter since the bulk is shared.
1147 	 */
1148 	reset_control_bulk_deassert(pcie->soc->phy_resets.num_resets,
1149 				    pcie->phy_resets);
1150 
1151 	/* Don't touch the hardware registers before power up */
1152 	err = pcie->soc->power_up(pcie);
1153 	if (err)
1154 		return err;
1155 
1156 	err = of_pci_get_max_link_speed(pcie->dev->of_node);
1157 	if (err) {
1158 		/* Get the maximum speed supported by the controller */
1159 		max_speed = mtk_pcie_get_controller_max_link_speed(pcie);
1160 
1161 		/* Set max_link_speed only if the controller supports it */
1162 		if (max_speed >= 0 && max_speed <= err) {
1163 			pcie->max_link_speed = err;
1164 			dev_info(pcie->dev,
1165 				 "maximum controller link speed Gen%d, overriding to Gen%u",
1166 				 max_speed, pcie->max_link_speed);
1167 		}
1168 	}
1169 
1170 	/* Try link up */
1171 	err = mtk_pcie_startup_port(pcie);
1172 	if (err)
1173 		goto err_setup;
1174 
1175 	err = mtk_pcie_setup_irq(pcie);
1176 	if (err)
1177 		goto err_setup;
1178 
1179 	return 0;
1180 
1181 err_setup:
1182 	mtk_pcie_power_down(pcie);
1183 
1184 	return err;
1185 }
1186 
mtk_pcie_probe(struct platform_device * pdev)1187 static int mtk_pcie_probe(struct platform_device *pdev)
1188 {
1189 	struct device *dev = &pdev->dev;
1190 	struct mtk_gen3_pcie *pcie;
1191 	struct pci_host_bridge *host;
1192 	int err;
1193 
1194 	host = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
1195 	if (!host)
1196 		return -ENOMEM;
1197 
1198 	pcie = pci_host_bridge_priv(host);
1199 
1200 	pcie->dev = dev;
1201 	pcie->soc = device_get_match_data(dev);
1202 	platform_set_drvdata(pdev, pcie);
1203 
1204 	err = mtk_pcie_setup(pcie);
1205 	if (err)
1206 		return err;
1207 
1208 	host->ops = &mtk_pcie_ops;
1209 	host->sysdata = pcie;
1210 
1211 	err = pci_host_probe(host);
1212 	if (err) {
1213 		mtk_pcie_irq_teardown(pcie);
1214 		mtk_pcie_power_down(pcie);
1215 		return err;
1216 	}
1217 
1218 	return 0;
1219 }
1220 
mtk_pcie_remove(struct platform_device * pdev)1221 static void mtk_pcie_remove(struct platform_device *pdev)
1222 {
1223 	struct mtk_gen3_pcie *pcie = platform_get_drvdata(pdev);
1224 	struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
1225 
1226 	pci_lock_rescan_remove();
1227 	pci_stop_root_bus(host->bus);
1228 	pci_remove_root_bus(host->bus);
1229 	pci_unlock_rescan_remove();
1230 
1231 	mtk_pcie_irq_teardown(pcie);
1232 	mtk_pcie_power_down(pcie);
1233 }
1234 
mtk_pcie_irq_save(struct mtk_gen3_pcie * pcie)1235 static void mtk_pcie_irq_save(struct mtk_gen3_pcie *pcie)
1236 {
1237 	int i;
1238 
1239 	raw_spin_lock(&pcie->irq_lock);
1240 
1241 	pcie->saved_irq_state = readl_relaxed(pcie->base + PCIE_INT_ENABLE_REG);
1242 
1243 	for (i = 0; i < PCIE_MSI_SET_NUM; i++) {
1244 		struct mtk_msi_set *msi_set = &pcie->msi_sets[i];
1245 
1246 		msi_set->saved_irq_state = readl_relaxed(msi_set->base +
1247 					   PCIE_MSI_SET_ENABLE_OFFSET);
1248 	}
1249 
1250 	raw_spin_unlock(&pcie->irq_lock);
1251 }
1252 
mtk_pcie_irq_restore(struct mtk_gen3_pcie * pcie)1253 static void mtk_pcie_irq_restore(struct mtk_gen3_pcie *pcie)
1254 {
1255 	int i;
1256 
1257 	raw_spin_lock(&pcie->irq_lock);
1258 
1259 	writel_relaxed(pcie->saved_irq_state, pcie->base + PCIE_INT_ENABLE_REG);
1260 
1261 	for (i = 0; i < PCIE_MSI_SET_NUM; i++) {
1262 		struct mtk_msi_set *msi_set = &pcie->msi_sets[i];
1263 
1264 		writel_relaxed(msi_set->saved_irq_state,
1265 			       msi_set->base + PCIE_MSI_SET_ENABLE_OFFSET);
1266 	}
1267 
1268 	raw_spin_unlock(&pcie->irq_lock);
1269 }
1270 
mtk_pcie_turn_off_link(struct mtk_gen3_pcie * pcie)1271 static int mtk_pcie_turn_off_link(struct mtk_gen3_pcie *pcie)
1272 {
1273 	u32 val;
1274 
1275 	val = readl_relaxed(pcie->base + PCIE_ICMD_PM_REG);
1276 	val |= PCIE_TURN_OFF_LINK;
1277 	writel_relaxed(val, pcie->base + PCIE_ICMD_PM_REG);
1278 
1279 	/* Check the link is L2 */
1280 	return readl_poll_timeout(pcie->base + PCIE_LTSSM_STATUS_REG, val,
1281 				  (PCIE_LTSSM_STATE(val) ==
1282 				   PCIE_LTSSM_STATE_L2_IDLE), 20,
1283 				   50 * USEC_PER_MSEC);
1284 }
1285 
mtk_pcie_suspend_noirq(struct device * dev)1286 static int mtk_pcie_suspend_noirq(struct device *dev)
1287 {
1288 	struct mtk_gen3_pcie *pcie = dev_get_drvdata(dev);
1289 	int err;
1290 	u32 val;
1291 
1292 	/* Trigger link to L2 state */
1293 	err = mtk_pcie_turn_off_link(pcie);
1294 	if (err) {
1295 		dev_err(pcie->dev, "cannot enter L2 state\n");
1296 		return err;
1297 	}
1298 
1299 	if (!(pcie->soc->flags & SKIP_PCIE_RSTB)) {
1300 		/* Assert the PERST# pin */
1301 		val = readl_relaxed(pcie->base + PCIE_RST_CTRL_REG);
1302 		val |= PCIE_PE_RSTB;
1303 		writel_relaxed(val, pcie->base + PCIE_RST_CTRL_REG);
1304 	}
1305 
1306 	dev_dbg(pcie->dev, "entered L2 states successfully");
1307 
1308 	mtk_pcie_irq_save(pcie);
1309 	mtk_pcie_power_down(pcie);
1310 
1311 	return 0;
1312 }
1313 
mtk_pcie_resume_noirq(struct device * dev)1314 static int mtk_pcie_resume_noirq(struct device *dev)
1315 {
1316 	struct mtk_gen3_pcie *pcie = dev_get_drvdata(dev);
1317 	int err;
1318 
1319 	err = pcie->soc->power_up(pcie);
1320 	if (err)
1321 		return err;
1322 
1323 	err = mtk_pcie_startup_port(pcie);
1324 	if (err) {
1325 		mtk_pcie_power_down(pcie);
1326 		return err;
1327 	}
1328 
1329 	mtk_pcie_irq_restore(pcie);
1330 
1331 	return 0;
1332 }
1333 
1334 static const struct dev_pm_ops mtk_pcie_pm_ops = {
1335 	NOIRQ_SYSTEM_SLEEP_PM_OPS(mtk_pcie_suspend_noirq,
1336 				  mtk_pcie_resume_noirq)
1337 };
1338 
1339 static const struct mtk_gen3_pcie_pdata mtk_pcie_soc_mt8192 = {
1340 	.power_up = mtk_pcie_power_up,
1341 	.phy_resets = {
1342 		.id[0] = "phy",
1343 		.num_resets = 1,
1344 	},
1345 };
1346 
1347 static const struct mtk_gen3_pcie_pdata mtk_pcie_soc_en7581 = {
1348 	.power_up = mtk_pcie_en7581_power_up,
1349 	.phy_resets = {
1350 		.id[0] = "phy-lane0",
1351 		.id[1] = "phy-lane1",
1352 		.id[2] = "phy-lane2",
1353 		.num_resets = 3,
1354 	},
1355 	.flags = SKIP_PCIE_RSTB,
1356 };
1357 
1358 static const struct of_device_id mtk_pcie_of_match[] = {
1359 	{ .compatible = "airoha,en7581-pcie", .data = &mtk_pcie_soc_en7581 },
1360 	{ .compatible = "mediatek,mt8192-pcie", .data = &mtk_pcie_soc_mt8192 },
1361 	{},
1362 };
1363 MODULE_DEVICE_TABLE(of, mtk_pcie_of_match);
1364 
1365 static struct platform_driver mtk_pcie_driver = {
1366 	.probe = mtk_pcie_probe,
1367 	.remove = mtk_pcie_remove,
1368 	.driver = {
1369 		.name = "mtk-pcie-gen3",
1370 		.of_match_table = mtk_pcie_of_match,
1371 		.pm = &mtk_pcie_pm_ops,
1372 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1373 	},
1374 };
1375 
1376 module_platform_driver(mtk_pcie_driver);
1377 MODULE_DESCRIPTION("MediaTek Gen3 PCIe host controller driver");
1378 MODULE_LICENSE("GPL v2");
1379