xref: /openbmc/linux/drivers/phy/qualcomm/phy-qcom-qusb2.c (revision b240b419db5d624ce7a5a397d6f62a1a686009ec)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2017, The Linux Foundation. All rights reserved.
4  */
5 
6 #include <linux/clk.h>
7 #include <linux/delay.h>
8 #include <linux/err.h>
9 #include <linux/io.h>
10 #include <linux/kernel.h>
11 #include <linux/mfd/syscon.h>
12 #include <linux/module.h>
13 #include <linux/nvmem-consumer.h>
14 #include <linux/of.h>
15 #include <linux/of_device.h>
16 #include <linux/phy/phy.h>
17 #include <linux/platform_device.h>
18 #include <linux/regmap.h>
19 #include <linux/regulator/consumer.h>
20 #include <linux/reset.h>
21 #include <linux/slab.h>
22 
23 #define QUSB2PHY_PLL_TEST		0x04
24 #define CLK_REF_SEL			BIT(7)
25 
26 #define QUSB2PHY_PLL_TUNE		0x08
27 #define QUSB2PHY_PLL_USER_CTL1		0x0c
28 #define QUSB2PHY_PLL_USER_CTL2		0x10
29 #define QUSB2PHY_PLL_AUTOPGM_CTL1	0x1c
30 #define QUSB2PHY_PLL_PWR_CTRL		0x18
31 
32 /* QUSB2PHY_PLL_STATUS register bits */
33 #define PLL_LOCKED			BIT(5)
34 
35 /* QUSB2PHY_PLL_COMMON_STATUS_ONE register bits */
36 #define CORE_READY_STATUS		BIT(0)
37 
38 /* QUSB2PHY_PORT_POWERDOWN register bits */
39 #define CLAMP_N_EN			BIT(5)
40 #define FREEZIO_N			BIT(1)
41 #define POWER_DOWN			BIT(0)
42 
43 /* QUSB2PHY_PWR_CTRL1 register bits */
44 #define PWR_CTRL1_VREF_SUPPLY_TRIM	BIT(5)
45 #define PWR_CTRL1_CLAMP_N_EN		BIT(1)
46 
47 #define QUSB2PHY_REFCLK_ENABLE		BIT(0)
48 
49 #define PHY_CLK_SCHEME_SEL		BIT(0)
50 
51 /* QUSB2PHY_INTR_CTRL register bits */
52 #define DMSE_INTR_HIGH_SEL			BIT(4)
53 #define DPSE_INTR_HIGH_SEL			BIT(3)
54 #define CHG_DET_INTR_EN				BIT(2)
55 #define DMSE_INTR_EN				BIT(1)
56 #define DPSE_INTR_EN				BIT(0)
57 
58 /* QUSB2PHY_PLL_CORE_INPUT_OVERRIDE register bits */
59 #define CORE_PLL_EN_FROM_RESET			BIT(4)
60 #define CORE_RESET				BIT(5)
61 #define CORE_RESET_MUX				BIT(6)
62 
63 #define QUSB2PHY_PLL_ANALOG_CONTROLS_TWO	0x04
64 #define QUSB2PHY_PLL_CLOCK_INVERTERS		0x18c
65 #define QUSB2PHY_PLL_CMODE			0x2c
66 #define QUSB2PHY_PLL_LOCK_DELAY			0x184
67 #define QUSB2PHY_PLL_DIGITAL_TIMERS_TWO		0xb4
68 #define QUSB2PHY_PLL_BIAS_CONTROL_1		0x194
69 #define QUSB2PHY_PLL_BIAS_CONTROL_2		0x198
70 #define QUSB2PHY_PWR_CTRL2			0x214
71 #define QUSB2PHY_IMP_CTRL1			0x220
72 #define QUSB2PHY_IMP_CTRL2			0x224
73 #define QUSB2PHY_CHG_CTRL2			0x23c
74 
75 struct qusb2_phy_init_tbl {
76 	unsigned int offset;
77 	unsigned int val;
78 	/*
79 	 * register part of layout ?
80 	 * if yes, then offset gives index in the reg-layout
81 	 */
82 	int in_layout;
83 };
84 
85 #define QUSB2_PHY_INIT_CFG(o, v) \
86 	{			\
87 		.offset = o,	\
88 		.val = v,	\
89 	}
90 
91 #define QUSB2_PHY_INIT_CFG_L(o, v) \
92 	{			\
93 		.offset = o,	\
94 		.val = v,	\
95 		.in_layout = 1,	\
96 	}
97 
98 /* set of registers with offsets different per-PHY */
99 enum qusb2phy_reg_layout {
100 	QUSB2PHY_PLL_CORE_INPUT_OVERRIDE,
101 	QUSB2PHY_PLL_STATUS,
102 	QUSB2PHY_PORT_TUNE1,
103 	QUSB2PHY_PORT_TUNE2,
104 	QUSB2PHY_PORT_TUNE3,
105 	QUSB2PHY_PORT_TUNE4,
106 	QUSB2PHY_PORT_TUNE5,
107 	QUSB2PHY_PORT_TEST1,
108 	QUSB2PHY_PORT_TEST2,
109 	QUSB2PHY_PORT_POWERDOWN,
110 	QUSB2PHY_INTR_CTRL,
111 };
112 
113 static const unsigned int msm8996_regs_layout[] = {
114 	[QUSB2PHY_PLL_STATUS]		= 0x38,
115 	[QUSB2PHY_PORT_TUNE1]		= 0x80,
116 	[QUSB2PHY_PORT_TUNE2]		= 0x84,
117 	[QUSB2PHY_PORT_TUNE3]		= 0x88,
118 	[QUSB2PHY_PORT_TUNE4]		= 0x8c,
119 	[QUSB2PHY_PORT_TUNE5]		= 0x90,
120 	[QUSB2PHY_PORT_TEST1]		= 0xb8,
121 	[QUSB2PHY_PORT_TEST2]		= 0x9c,
122 	[QUSB2PHY_PORT_POWERDOWN]	= 0xb4,
123 	[QUSB2PHY_INTR_CTRL]		= 0xbc,
124 };
125 
126 static const struct qusb2_phy_init_tbl msm8996_init_tbl[] = {
127 	QUSB2_PHY_INIT_CFG_L(QUSB2PHY_PORT_TUNE1, 0xf8),
128 	QUSB2_PHY_INIT_CFG_L(QUSB2PHY_PORT_TUNE2, 0xb3),
129 	QUSB2_PHY_INIT_CFG_L(QUSB2PHY_PORT_TUNE3, 0x83),
130 	QUSB2_PHY_INIT_CFG_L(QUSB2PHY_PORT_TUNE4, 0xc0),
131 
132 	QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_TUNE, 0x30),
133 	QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_USER_CTL1, 0x79),
134 	QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_USER_CTL2, 0x21),
135 
136 	QUSB2_PHY_INIT_CFG_L(QUSB2PHY_PORT_TEST2, 0x14),
137 
138 	QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_AUTOPGM_CTL1, 0x9f),
139 	QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_PWR_CTRL, 0x00),
140 };
141 
142 static const unsigned int qusb2_v2_regs_layout[] = {
143 	[QUSB2PHY_PLL_CORE_INPUT_OVERRIDE] = 0xa8,
144 	[QUSB2PHY_PLL_STATUS]		= 0x1a0,
145 	[QUSB2PHY_PORT_TUNE1]		= 0x240,
146 	[QUSB2PHY_PORT_TUNE2]		= 0x244,
147 	[QUSB2PHY_PORT_TUNE3]		= 0x248,
148 	[QUSB2PHY_PORT_TUNE4]		= 0x24c,
149 	[QUSB2PHY_PORT_TUNE5]		= 0x250,
150 	[QUSB2PHY_PORT_TEST1]		= 0x254,
151 	[QUSB2PHY_PORT_TEST2]		= 0x258,
152 	[QUSB2PHY_PORT_POWERDOWN]	= 0x210,
153 	[QUSB2PHY_INTR_CTRL]		= 0x230,
154 };
155 
156 static const struct qusb2_phy_init_tbl qusb2_v2_init_tbl[] = {
157 	QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_ANALOG_CONTROLS_TWO, 0x03),
158 	QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_CLOCK_INVERTERS, 0x7c),
159 	QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_CMODE, 0x80),
160 	QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_LOCK_DELAY, 0x0a),
161 	QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_DIGITAL_TIMERS_TWO, 0x19),
162 	QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_BIAS_CONTROL_1, 0x40),
163 	QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_BIAS_CONTROL_2, 0x20),
164 	QUSB2_PHY_INIT_CFG(QUSB2PHY_PWR_CTRL2, 0x21),
165 	QUSB2_PHY_INIT_CFG(QUSB2PHY_IMP_CTRL1, 0x0),
166 	QUSB2_PHY_INIT_CFG(QUSB2PHY_IMP_CTRL2, 0x58),
167 
168 	QUSB2_PHY_INIT_CFG_L(QUSB2PHY_PORT_TUNE1, 0x30),
169 	QUSB2_PHY_INIT_CFG_L(QUSB2PHY_PORT_TUNE2, 0x29),
170 	QUSB2_PHY_INIT_CFG_L(QUSB2PHY_PORT_TUNE3, 0xca),
171 	QUSB2_PHY_INIT_CFG_L(QUSB2PHY_PORT_TUNE4, 0x04),
172 	QUSB2_PHY_INIT_CFG_L(QUSB2PHY_PORT_TUNE5, 0x03),
173 
174 	QUSB2_PHY_INIT_CFG(QUSB2PHY_CHG_CTRL2, 0x0),
175 };
176 
177 struct qusb2_phy_cfg {
178 	const struct qusb2_phy_init_tbl *tbl;
179 	/* number of entries in the table */
180 	unsigned int tbl_num;
181 	/* offset to PHY_CLK_SCHEME register in TCSR map */
182 	unsigned int clk_scheme_offset;
183 
184 	/* array of registers with different offsets */
185 	const unsigned int *regs;
186 	unsigned int mask_core_ready;
187 	unsigned int disable_ctrl;
188 	unsigned int autoresume_en;
189 
190 	/* true if PHY has PLL_TEST register to select clk_scheme */
191 	bool has_pll_test;
192 
193 	/* true if TUNE1 register must be updated by fused value, else TUNE2 */
194 	bool update_tune1_with_efuse;
195 
196 	/* true if PHY has PLL_CORE_INPUT_OVERRIDE register to reset PLL */
197 	bool has_pll_override;
198 };
199 
200 static const struct qusb2_phy_cfg msm8996_phy_cfg = {
201 	.tbl		= msm8996_init_tbl,
202 	.tbl_num	= ARRAY_SIZE(msm8996_init_tbl),
203 	.regs		= msm8996_regs_layout,
204 
205 	.has_pll_test	= true,
206 	.disable_ctrl	= (CLAMP_N_EN | FREEZIO_N | POWER_DOWN),
207 	.mask_core_ready = PLL_LOCKED,
208 	.autoresume_en	 = BIT(3),
209 };
210 
211 static const struct qusb2_phy_cfg qusb2_v2_phy_cfg = {
212 	.tbl		= qusb2_v2_init_tbl,
213 	.tbl_num	= ARRAY_SIZE(qusb2_v2_init_tbl),
214 	.regs		= qusb2_v2_regs_layout,
215 
216 	.disable_ctrl	= (PWR_CTRL1_VREF_SUPPLY_TRIM | PWR_CTRL1_CLAMP_N_EN |
217 			   POWER_DOWN),
218 	.mask_core_ready = CORE_READY_STATUS,
219 	.has_pll_override = true,
220 	.autoresume_en	  = BIT(0),
221 };
222 
223 static const char * const qusb2_phy_vreg_names[] = {
224 	"vdda-pll", "vdda-phy-dpdm",
225 };
226 
227 #define QUSB2_NUM_VREGS		ARRAY_SIZE(qusb2_phy_vreg_names)
228 
229 /**
230  * struct qusb2_phy - structure holding qusb2 phy attributes
231  *
232  * @phy: generic phy
233  * @base: iomapped memory space for qubs2 phy
234  *
235  * @cfg_ahb_clk: AHB2PHY interface clock
236  * @ref_clk: phy reference clock
237  * @iface_clk: phy interface clock
238  * @phy_reset: phy reset control
239  * @vregs: regulator supplies bulk data
240  *
241  * @tcsr: TCSR syscon register map
242  * @cell: nvmem cell containing phy tuning value
243  *
244  * @cfg: phy config data
245  * @has_se_clk_scheme: indicate if PHY has single-ended ref clock scheme
246  * @phy_initialized: indicate if PHY has been initialized
247  * @mode: current PHY mode
248  */
249 struct qusb2_phy {
250 	struct phy *phy;
251 	void __iomem *base;
252 
253 	struct clk *cfg_ahb_clk;
254 	struct clk *ref_clk;
255 	struct clk *iface_clk;
256 	struct reset_control *phy_reset;
257 	struct regulator_bulk_data vregs[QUSB2_NUM_VREGS];
258 
259 	struct regmap *tcsr;
260 	struct nvmem_cell *cell;
261 
262 	const struct qusb2_phy_cfg *cfg;
263 	bool has_se_clk_scheme;
264 	bool phy_initialized;
265 	enum phy_mode mode;
266 };
267 
268 static inline void qusb2_setbits(void __iomem *base, u32 offset, u32 val)
269 {
270 	u32 reg;
271 
272 	reg = readl(base + offset);
273 	reg |= val;
274 	writel(reg, base + offset);
275 
276 	/* Ensure above write is completed */
277 	readl(base + offset);
278 }
279 
280 static inline void qusb2_clrbits(void __iomem *base, u32 offset, u32 val)
281 {
282 	u32 reg;
283 
284 	reg = readl(base + offset);
285 	reg &= ~val;
286 	writel(reg, base + offset);
287 
288 	/* Ensure above write is completed */
289 	readl(base + offset);
290 }
291 
292 static inline
293 void qcom_qusb2_phy_configure(void __iomem *base,
294 			      const unsigned int *regs,
295 			      const struct qusb2_phy_init_tbl tbl[], int num)
296 {
297 	int i;
298 
299 	for (i = 0; i < num; i++) {
300 		if (tbl[i].in_layout)
301 			writel(tbl[i].val, base + regs[tbl[i].offset]);
302 		else
303 			writel(tbl[i].val, base + tbl[i].offset);
304 	}
305 }
306 
307 /*
308  * Fetches HS Tx tuning value from nvmem and sets the
309  * QUSB2PHY_PORT_TUNE1/2 register.
310  * For error case, skip setting the value and use the default value.
311  */
312 static void qusb2_phy_set_tune2_param(struct qusb2_phy *qphy)
313 {
314 	struct device *dev = &qphy->phy->dev;
315 	const struct qusb2_phy_cfg *cfg = qphy->cfg;
316 	u8 *val;
317 
318 	/*
319 	 * Read efuse register having TUNE2/1 parameter's high nibble.
320 	 * If efuse register shows value as 0x0, or if we fail to find
321 	 * a valid efuse register settings, then use default value
322 	 * as 0xB for high nibble that we have already set while
323 	 * configuring phy.
324 	 */
325 	val = nvmem_cell_read(qphy->cell, NULL);
326 	if (IS_ERR(val) || !val[0]) {
327 		dev_dbg(dev, "failed to read a valid hs-tx trim value\n");
328 		return;
329 	}
330 
331 	/* Fused TUNE1/2 value is the higher nibble only */
332 	if (cfg->update_tune1_with_efuse)
333 		qusb2_setbits(qphy->base, cfg->regs[QUSB2PHY_PORT_TUNE1],
334 			      val[0] << 0x4);
335 	else
336 		qusb2_setbits(qphy->base, cfg->regs[QUSB2PHY_PORT_TUNE2],
337 			      val[0] << 0x4);
338 
339 }
340 
341 static int qusb2_phy_set_mode(struct phy *phy, enum phy_mode mode)
342 {
343 	struct qusb2_phy *qphy = phy_get_drvdata(phy);
344 
345 	qphy->mode = mode;
346 
347 	return 0;
348 }
349 
350 static int __maybe_unused qusb2_phy_runtime_suspend(struct device *dev)
351 {
352 	struct qusb2_phy *qphy = dev_get_drvdata(dev);
353 	const struct qusb2_phy_cfg *cfg = qphy->cfg;
354 	u32 intr_mask;
355 
356 	dev_vdbg(dev, "Suspending QUSB2 Phy, mode:%d\n", qphy->mode);
357 
358 	if (!qphy->phy_initialized) {
359 		dev_vdbg(dev, "PHY not initialized, bailing out\n");
360 		return 0;
361 	}
362 
363 	/*
364 	 * Enable DP/DM interrupts to detect line state changes based on current
365 	 * speed. In other words, enable the triggers _opposite_ of what the
366 	 * current D+/D- levels are e.g. if currently D+ high, D- low
367 	 * (HS 'J'/Suspend), configure the mask to trigger on D+ low OR D- high
368 	 */
369 	intr_mask = DPSE_INTR_EN | DMSE_INTR_EN;
370 	switch (qphy->mode) {
371 	case PHY_MODE_USB_HOST_HS:
372 	case PHY_MODE_USB_HOST_FS:
373 	case PHY_MODE_USB_DEVICE_HS:
374 	case PHY_MODE_USB_DEVICE_FS:
375 		intr_mask |= DMSE_INTR_HIGH_SEL;
376 		break;
377 	case PHY_MODE_USB_HOST_LS:
378 	case PHY_MODE_USB_DEVICE_LS:
379 		intr_mask |= DPSE_INTR_HIGH_SEL;
380 		break;
381 	default:
382 		/* No device connected, enable both DP/DM high interrupt */
383 		intr_mask |= DMSE_INTR_HIGH_SEL;
384 		intr_mask |= DPSE_INTR_HIGH_SEL;
385 		break;
386 	}
387 
388 	writel(intr_mask, qphy->base + cfg->regs[QUSB2PHY_INTR_CTRL]);
389 
390 	/* hold core PLL into reset */
391 	if (cfg->has_pll_override) {
392 		qusb2_setbits(qphy->base,
393 			      cfg->regs[QUSB2PHY_PLL_CORE_INPUT_OVERRIDE],
394 			      CORE_PLL_EN_FROM_RESET | CORE_RESET |
395 			      CORE_RESET_MUX);
396 	}
397 
398 	/* enable phy auto-resume only if device is connected on bus */
399 	if (qphy->mode != PHY_MODE_INVALID) {
400 		qusb2_setbits(qphy->base, cfg->regs[QUSB2PHY_PORT_TEST1],
401 			      cfg->autoresume_en);
402 		/* Autoresume bit has to be toggled in order to enable it */
403 		qusb2_clrbits(qphy->base, cfg->regs[QUSB2PHY_PORT_TEST1],
404 			      cfg->autoresume_en);
405 	}
406 
407 	if (!qphy->has_se_clk_scheme)
408 		clk_disable_unprepare(qphy->ref_clk);
409 
410 	clk_disable_unprepare(qphy->cfg_ahb_clk);
411 	clk_disable_unprepare(qphy->iface_clk);
412 
413 	return 0;
414 }
415 
416 static int __maybe_unused qusb2_phy_runtime_resume(struct device *dev)
417 {
418 	struct qusb2_phy *qphy = dev_get_drvdata(dev);
419 	const struct qusb2_phy_cfg *cfg = qphy->cfg;
420 	int ret;
421 
422 	dev_vdbg(dev, "Resuming QUSB2 phy, mode:%d\n", qphy->mode);
423 
424 	if (!qphy->phy_initialized) {
425 		dev_vdbg(dev, "PHY not initialized, bailing out\n");
426 		return 0;
427 	}
428 
429 	ret = clk_prepare_enable(qphy->iface_clk);
430 	if (ret) {
431 		dev_err(dev, "failed to enable iface_clk, %d\n", ret);
432 		return ret;
433 	}
434 
435 	ret = clk_prepare_enable(qphy->cfg_ahb_clk);
436 	if (ret) {
437 		dev_err(dev, "failed to enable cfg ahb clock, %d\n", ret);
438 		goto disable_iface_clk;
439 	}
440 
441 	if (!qphy->has_se_clk_scheme) {
442 		clk_prepare_enable(qphy->ref_clk);
443 		if (ret) {
444 			dev_err(dev, "failed to enable ref clk, %d\n", ret);
445 			goto disable_ahb_clk;
446 		}
447 	}
448 
449 	writel(0x0, qphy->base + cfg->regs[QUSB2PHY_INTR_CTRL]);
450 
451 	/* bring core PLL out of reset */
452 	if (cfg->has_pll_override) {
453 		qusb2_clrbits(qphy->base,
454 			      cfg->regs[QUSB2PHY_PLL_CORE_INPUT_OVERRIDE],
455 			      CORE_RESET | CORE_RESET_MUX);
456 	}
457 
458 	return 0;
459 
460 disable_ahb_clk:
461 	clk_disable_unprepare(qphy->cfg_ahb_clk);
462 disable_iface_clk:
463 	clk_disable_unprepare(qphy->iface_clk);
464 
465 	return ret;
466 }
467 
468 static int qusb2_phy_init(struct phy *phy)
469 {
470 	struct qusb2_phy *qphy = phy_get_drvdata(phy);
471 	const struct qusb2_phy_cfg *cfg = qphy->cfg;
472 	unsigned int val = 0;
473 	unsigned int clk_scheme;
474 	int ret;
475 
476 	dev_vdbg(&phy->dev, "%s(): Initializing QUSB2 phy\n", __func__);
477 
478 	/* turn on regulator supplies */
479 	ret = regulator_bulk_enable(ARRAY_SIZE(qphy->vregs), qphy->vregs);
480 	if (ret)
481 		return ret;
482 
483 	ret = clk_prepare_enable(qphy->iface_clk);
484 	if (ret) {
485 		dev_err(&phy->dev, "failed to enable iface_clk, %d\n", ret);
486 		goto poweroff_phy;
487 	}
488 
489 	/* enable ahb interface clock to program phy */
490 	ret = clk_prepare_enable(qphy->cfg_ahb_clk);
491 	if (ret) {
492 		dev_err(&phy->dev, "failed to enable cfg ahb clock, %d\n", ret);
493 		goto disable_iface_clk;
494 	}
495 
496 	/* Perform phy reset */
497 	ret = reset_control_assert(qphy->phy_reset);
498 	if (ret) {
499 		dev_err(&phy->dev, "failed to assert phy_reset, %d\n", ret);
500 		goto disable_ahb_clk;
501 	}
502 
503 	/* 100 us delay to keep PHY in reset mode */
504 	usleep_range(100, 150);
505 
506 	ret = reset_control_deassert(qphy->phy_reset);
507 	if (ret) {
508 		dev_err(&phy->dev, "failed to de-assert phy_reset, %d\n", ret);
509 		goto disable_ahb_clk;
510 	}
511 
512 	/* Disable the PHY */
513 	qusb2_setbits(qphy->base, cfg->regs[QUSB2PHY_PORT_POWERDOWN],
514 		      qphy->cfg->disable_ctrl);
515 
516 	if (cfg->has_pll_test) {
517 		/* save reset value to override reference clock scheme later */
518 		val = readl(qphy->base + QUSB2PHY_PLL_TEST);
519 	}
520 
521 	qcom_qusb2_phy_configure(qphy->base, cfg->regs, cfg->tbl,
522 				 cfg->tbl_num);
523 
524 	/* Set efuse value for tuning the PHY */
525 	qusb2_phy_set_tune2_param(qphy);
526 
527 	/* Enable the PHY */
528 	qusb2_clrbits(qphy->base, cfg->regs[QUSB2PHY_PORT_POWERDOWN],
529 		      POWER_DOWN);
530 
531 	/* Required to get phy pll lock successfully */
532 	usleep_range(150, 160);
533 
534 	/* Default is single-ended clock on msm8996 */
535 	qphy->has_se_clk_scheme = true;
536 	/*
537 	 * read TCSR_PHY_CLK_SCHEME register to check if single-ended
538 	 * clock scheme is selected. If yes, then disable differential
539 	 * ref_clk and use single-ended clock, otherwise use differential
540 	 * ref_clk only.
541 	 */
542 	if (qphy->tcsr) {
543 		ret = regmap_read(qphy->tcsr, qphy->cfg->clk_scheme_offset,
544 				  &clk_scheme);
545 		if (ret) {
546 			dev_err(&phy->dev, "failed to read clk scheme reg\n");
547 			goto assert_phy_reset;
548 		}
549 
550 		/* is it a differential clock scheme ? */
551 		if (!(clk_scheme & PHY_CLK_SCHEME_SEL)) {
552 			dev_vdbg(&phy->dev, "%s(): select differential clk\n",
553 				 __func__);
554 			qphy->has_se_clk_scheme = false;
555 		} else {
556 			dev_vdbg(&phy->dev, "%s(): select single-ended clk\n",
557 				 __func__);
558 		}
559 	}
560 
561 	if (!qphy->has_se_clk_scheme) {
562 		ret = clk_prepare_enable(qphy->ref_clk);
563 		if (ret) {
564 			dev_err(&phy->dev, "failed to enable ref clk, %d\n",
565 				ret);
566 			goto assert_phy_reset;
567 		}
568 	}
569 
570 	if (cfg->has_pll_test) {
571 		if (!qphy->has_se_clk_scheme)
572 			val &= ~CLK_REF_SEL;
573 		else
574 			val |= CLK_REF_SEL;
575 
576 		writel(val, qphy->base + QUSB2PHY_PLL_TEST);
577 
578 		/* ensure above write is through */
579 		readl(qphy->base + QUSB2PHY_PLL_TEST);
580 	}
581 
582 	/* Required to get phy pll lock successfully */
583 	usleep_range(100, 110);
584 
585 	val = readb(qphy->base + cfg->regs[QUSB2PHY_PLL_STATUS]);
586 	if (!(val & cfg->mask_core_ready)) {
587 		dev_err(&phy->dev,
588 			"QUSB2PHY pll lock failed: status reg = %x\n", val);
589 		ret = -EBUSY;
590 		goto disable_ref_clk;
591 	}
592 	qphy->phy_initialized = true;
593 
594 	return 0;
595 
596 disable_ref_clk:
597 	if (!qphy->has_se_clk_scheme)
598 		clk_disable_unprepare(qphy->ref_clk);
599 assert_phy_reset:
600 	reset_control_assert(qphy->phy_reset);
601 disable_ahb_clk:
602 	clk_disable_unprepare(qphy->cfg_ahb_clk);
603 disable_iface_clk:
604 	clk_disable_unprepare(qphy->iface_clk);
605 poweroff_phy:
606 	regulator_bulk_disable(ARRAY_SIZE(qphy->vregs), qphy->vregs);
607 
608 	return ret;
609 }
610 
611 static int qusb2_phy_exit(struct phy *phy)
612 {
613 	struct qusb2_phy *qphy = phy_get_drvdata(phy);
614 
615 	/* Disable the PHY */
616 	qusb2_setbits(qphy->base, qphy->cfg->regs[QUSB2PHY_PORT_POWERDOWN],
617 		      qphy->cfg->disable_ctrl);
618 
619 	if (!qphy->has_se_clk_scheme)
620 		clk_disable_unprepare(qphy->ref_clk);
621 
622 	reset_control_assert(qphy->phy_reset);
623 
624 	clk_disable_unprepare(qphy->cfg_ahb_clk);
625 	clk_disable_unprepare(qphy->iface_clk);
626 
627 	regulator_bulk_disable(ARRAY_SIZE(qphy->vregs), qphy->vregs);
628 
629 	qphy->phy_initialized = false;
630 
631 	return 0;
632 }
633 
634 static const struct phy_ops qusb2_phy_gen_ops = {
635 	.init		= qusb2_phy_init,
636 	.exit		= qusb2_phy_exit,
637 	.set_mode	= qusb2_phy_set_mode,
638 	.owner		= THIS_MODULE,
639 };
640 
641 static const struct of_device_id qusb2_phy_of_match_table[] = {
642 	{
643 		.compatible	= "qcom,msm8996-qusb2-phy",
644 		.data		= &msm8996_phy_cfg,
645 	}, {
646 		.compatible	= "qcom,qusb2-v2-phy",
647 		.data		= &qusb2_v2_phy_cfg,
648 	},
649 	{ },
650 };
651 MODULE_DEVICE_TABLE(of, qusb2_phy_of_match_table);
652 
653 static const struct dev_pm_ops qusb2_phy_pm_ops = {
654 	SET_RUNTIME_PM_OPS(qusb2_phy_runtime_suspend,
655 			   qusb2_phy_runtime_resume, NULL)
656 };
657 
658 static int qusb2_phy_probe(struct platform_device *pdev)
659 {
660 	struct device *dev = &pdev->dev;
661 	struct qusb2_phy *qphy;
662 	struct phy_provider *phy_provider;
663 	struct phy *generic_phy;
664 	struct resource *res;
665 	int ret, i;
666 	int num;
667 
668 	qphy = devm_kzalloc(dev, sizeof(*qphy), GFP_KERNEL);
669 	if (!qphy)
670 		return -ENOMEM;
671 
672 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
673 	qphy->base = devm_ioremap_resource(dev, res);
674 	if (IS_ERR(qphy->base))
675 		return PTR_ERR(qphy->base);
676 
677 	qphy->cfg_ahb_clk = devm_clk_get(dev, "cfg_ahb");
678 	if (IS_ERR(qphy->cfg_ahb_clk)) {
679 		ret = PTR_ERR(qphy->cfg_ahb_clk);
680 		if (ret != -EPROBE_DEFER)
681 			dev_err(dev, "failed to get cfg ahb clk, %d\n", ret);
682 		return ret;
683 	}
684 
685 	qphy->ref_clk = devm_clk_get(dev, "ref");
686 	if (IS_ERR(qphy->ref_clk)) {
687 		ret = PTR_ERR(qphy->ref_clk);
688 		if (ret != -EPROBE_DEFER)
689 			dev_err(dev, "failed to get ref clk, %d\n", ret);
690 		return ret;
691 	}
692 
693 	qphy->iface_clk = devm_clk_get(dev, "iface");
694 	if (IS_ERR(qphy->iface_clk)) {
695 		ret = PTR_ERR(qphy->iface_clk);
696 		if (ret == -EPROBE_DEFER)
697 			return ret;
698 		qphy->iface_clk = NULL;
699 		dev_dbg(dev, "failed to get iface clk, %d\n", ret);
700 	}
701 
702 	qphy->phy_reset = devm_reset_control_get_by_index(&pdev->dev, 0);
703 	if (IS_ERR(qphy->phy_reset)) {
704 		dev_err(dev, "failed to get phy core reset\n");
705 		return PTR_ERR(qphy->phy_reset);
706 	}
707 
708 	num = ARRAY_SIZE(qphy->vregs);
709 	for (i = 0; i < num; i++)
710 		qphy->vregs[i].supply = qusb2_phy_vreg_names[i];
711 
712 	ret = devm_regulator_bulk_get(dev, num, qphy->vregs);
713 	if (ret) {
714 		dev_err(dev, "failed to get regulator supplies\n");
715 		return ret;
716 	}
717 
718 	/* Get the specific init parameters of QMP phy */
719 	qphy->cfg = of_device_get_match_data(dev);
720 
721 	qphy->tcsr = syscon_regmap_lookup_by_phandle(dev->of_node,
722 							"qcom,tcsr-syscon");
723 	if (IS_ERR(qphy->tcsr)) {
724 		dev_dbg(dev, "failed to lookup TCSR regmap\n");
725 		qphy->tcsr = NULL;
726 	}
727 
728 	qphy->cell = devm_nvmem_cell_get(dev, NULL);
729 	if (IS_ERR(qphy->cell)) {
730 		if (PTR_ERR(qphy->cell) == -EPROBE_DEFER)
731 			return -EPROBE_DEFER;
732 		qphy->cell = NULL;
733 		dev_dbg(dev, "failed to lookup tune2 hstx trim value\n");
734 	}
735 	pm_runtime_set_active(dev);
736 	pm_runtime_enable(dev);
737 	/*
738 	 * Prevent runtime pm from being ON by default. Users can enable
739 	 * it using power/control in sysfs.
740 	 */
741 	pm_runtime_forbid(dev);
742 
743 	generic_phy = devm_phy_create(dev, NULL, &qusb2_phy_gen_ops);
744 	if (IS_ERR(generic_phy)) {
745 		ret = PTR_ERR(generic_phy);
746 		dev_err(dev, "failed to create phy, %d\n", ret);
747 		pm_runtime_disable(dev);
748 		return ret;
749 	}
750 	qphy->phy = generic_phy;
751 
752 	dev_set_drvdata(dev, qphy);
753 	phy_set_drvdata(generic_phy, qphy);
754 
755 	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
756 	if (!IS_ERR(phy_provider))
757 		dev_info(dev, "Registered Qcom-QUSB2 phy\n");
758 	else
759 		pm_runtime_disable(dev);
760 
761 	return PTR_ERR_OR_ZERO(phy_provider);
762 }
763 
764 static struct platform_driver qusb2_phy_driver = {
765 	.probe		= qusb2_phy_probe,
766 	.driver = {
767 		.name	= "qcom-qusb2-phy",
768 		.pm	= &qusb2_phy_pm_ops,
769 		.of_match_table = qusb2_phy_of_match_table,
770 	},
771 };
772 
773 module_platform_driver(qusb2_phy_driver);
774 
775 MODULE_AUTHOR("Vivek Gautam <vivek.gautam@codeaurora.org>");
776 MODULE_DESCRIPTION("Qualcomm QUSB2 PHY driver");
777 MODULE_LICENSE("GPL v2");
778