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1// SPDX-Licence-Identifier: GPL-2.0
2/*
3 * STMicroelectronics STM32 USB PHY Controller driver
4 *
5 * Copyright (C) 2018 STMicroelectronics
6 * Author(s): Amelie Delaunay <amelie.delaunay@st.com>.
7 */
8#include <linux/bitfield.h>
9#include <linux/clk.h>
10#include <linux/delay.h>
11#include <linux/io.h>
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/of_platform.h>
15#include <linux/phy/phy.h>
16#include <linux/reset.h>
17
18#define STM32_USBPHYC_PLL 0x0
19#define STM32_USBPHYC_MISC 0x8
20#define STM32_USBPHYC_VERSION 0x3F4
21
22/* STM32_USBPHYC_PLL bit fields */
23#define PLLNDIV GENMASK(6, 0)
24#define PLLFRACIN GENMASK(25, 10)
25#define PLLEN BIT(26)
26#define PLLSTRB BIT(27)
27#define PLLSTRBYP BIT(28)
28#define PLLFRACCTL BIT(29)
29#define PLLDITHEN0 BIT(30)
30#define PLLDITHEN1 BIT(31)
31
32/* STM32_USBPHYC_MISC bit fields */
33#define SWITHOST BIT(0)
34
35/* STM32_USBPHYC_VERSION bit fields */
36#define MINREV GENMASK(3, 0)
37#define MAJREV GENMASK(7, 4)
38
39static const char * const supplies_names[] = {
40 "vdda1v1", /* 1V1 */
41 "vdda1v8", /* 1V8 */
42};
43
44#define NUM_SUPPLIES ARRAY_SIZE(supplies_names)
45
46#define PLL_LOCK_TIME_US 100
47#define PLL_PWR_DOWN_TIME_US 5
48#define PLL_FVCO_MHZ 2880
49#define PLL_INFF_MIN_RATE_HZ 19200000
50#define PLL_INFF_MAX_RATE_HZ 38400000
51#define HZ_PER_MHZ 1000000L
52
53struct pll_params {
54 u8 ndiv;
55 u16 frac;
56};
57
58struct stm32_usbphyc_phy {
59 struct phy *phy;
60 struct stm32_usbphyc *usbphyc;
61 struct regulator_bulk_data supplies[NUM_SUPPLIES];
62 u32 index;
63 bool active;
64};
65
66struct stm32_usbphyc {
67 struct device *dev;
68 void __iomem *base;
69 struct clk *clk;
70 struct reset_control *rst;
71 struct stm32_usbphyc_phy **phys;
72 int nphys;
73 int switch_setup;
74 bool pll_enabled;
75};
76
77static inline void stm32_usbphyc_set_bits(void __iomem *reg, u32 bits)
78{
79 writel_relaxed(readl_relaxed(reg) | bits, reg);
80}
81
82static inline void stm32_usbphyc_clr_bits(void __iomem *reg, u32 bits)
83{
84 writel_relaxed(readl_relaxed(reg) & ~bits, reg);
85}
86
87static void stm32_usbphyc_get_pll_params(u32 clk_rate, struct pll_params *pll_params)
88{
89 unsigned long long fvco, ndiv, frac;
90
91 /* _
92 * | FVCO = INFF*2*(NDIV + FRACT/2^16) when DITHER_DISABLE[1] = 1
93 * | FVCO = 2880MHz
94 * <
95 * | NDIV = integer part of input bits to set the LDF
96 * |_FRACT = fractional part of input bits to set the LDF
97 * => PLLNDIV = integer part of (FVCO / (INFF*2))
98 * => PLLFRACIN = fractional part of(FVCO / INFF*2) * 2^16
99 * <=> PLLFRACIN = ((FVCO / (INFF*2)) - PLLNDIV) * 2^16
100 */
101 fvco = (unsigned long long)PLL_FVCO_MHZ * HZ_PER_MHZ;
102
103 ndiv = fvco;
104 do_div(ndiv, (clk_rate * 2));
105 pll_params->ndiv = (u8)ndiv;
106
107 frac = fvco * (1 << 16);
108 do_div(frac, (clk_rate * 2));
109 frac = frac - (ndiv * (1 << 16));
110 pll_params->frac = (u16)frac;
111}
112
113static int stm32_usbphyc_pll_init(struct stm32_usbphyc *usbphyc)
114{
115 struct pll_params pll_params;
116 u32 clk_rate = clk_get_rate(usbphyc->clk);
117 u32 ndiv, frac;
118 u32 usbphyc_pll;
119
120 if ((clk_rate < PLL_INFF_MIN_RATE_HZ) ||
121 (clk_rate > PLL_INFF_MAX_RATE_HZ)) {
122 dev_err(usbphyc->dev, "input clk freq (%dHz) out of range\n",
123 clk_rate);
124 return -EINVAL;
125 }
126
127 stm32_usbphyc_get_pll_params(clk_rate, &pll_params);
128 ndiv = FIELD_PREP(PLLNDIV, pll_params.ndiv);
129 frac = FIELD_PREP(PLLFRACIN, pll_params.frac);
130
131 usbphyc_pll = PLLDITHEN1 | PLLDITHEN0 | PLLSTRBYP | ndiv;
132
133 if (pll_params.frac)
134 usbphyc_pll |= PLLFRACCTL | frac;
135
136 writel_relaxed(usbphyc_pll, usbphyc->base + STM32_USBPHYC_PLL);
137
138 dev_dbg(usbphyc->dev, "input clk freq=%dHz, ndiv=%lu, frac=%lu\n",
139 clk_rate, FIELD_GET(PLLNDIV, usbphyc_pll),
140 FIELD_GET(PLLFRACIN, usbphyc_pll));
141
142 return 0;
143}
144
145static bool stm32_usbphyc_has_one_phy_active(struct stm32_usbphyc *usbphyc)
146{
147 int i;
148
149 for (i = 0; i < usbphyc->nphys; i++)
150 if (usbphyc->phys[i]->active)
151 return true;
152
153 return false;
154}
155
156static int stm32_usbphyc_pll_enable(struct stm32_usbphyc *usbphyc)
157{
158 void __iomem *pll_reg = usbphyc->base + STM32_USBPHYC_PLL;
159 bool pllen = (readl_relaxed(pll_reg) & PLLEN);
160 int ret;
161
162 /* Check if one phy port has already configured the pll */
163 if (pllen && stm32_usbphyc_has_one_phy_active(usbphyc))
164 return 0;
165
166 if (pllen) {
167 stm32_usbphyc_clr_bits(pll_reg, PLLEN);
168 /* Wait for minimum width of powerdown pulse (ENABLE = Low) */
169 udelay(PLL_PWR_DOWN_TIME_US);
170 }
171
172 ret = stm32_usbphyc_pll_init(usbphyc);
173 if (ret)
174 return ret;
175
176 stm32_usbphyc_set_bits(pll_reg, PLLEN);
177
178 /* Wait for maximum lock time */
179 udelay(PLL_LOCK_TIME_US);
180
181 if (!(readl_relaxed(pll_reg) & PLLEN)) {
182 dev_err(usbphyc->dev, "PLLEN not set\n");
183 return -EIO;
184 }
185
186 return 0;
187}
188
189static int stm32_usbphyc_pll_disable(struct stm32_usbphyc *usbphyc)
190{
191 void __iomem *pll_reg = usbphyc->base + STM32_USBPHYC_PLL;
192
193 /* Check if other phy port active */
194 if (stm32_usbphyc_has_one_phy_active(usbphyc))
195 return 0;
196
197 stm32_usbphyc_clr_bits(pll_reg, PLLEN);
198 /* Wait for minimum width of powerdown pulse (ENABLE = Low) */
199 udelay(PLL_PWR_DOWN_TIME_US);
200
201 if (readl_relaxed(pll_reg) & PLLEN) {
202 dev_err(usbphyc->dev, "PLL not reset\n");
203 return -EIO;
204 }
205
206 return 0;
207}
208
209static int stm32_usbphyc_phy_init(struct phy *phy)
210{
211 struct stm32_usbphyc_phy *usbphyc_phy = phy_get_drvdata(phy);
212 struct stm32_usbphyc *usbphyc = usbphyc_phy->usbphyc;
213 int ret;
214
215 ret = stm32_usbphyc_pll_enable(usbphyc);
216 if (ret)
217 return ret;
218
219 usbphyc_phy->active = true;
220
221 return 0;
222}
223
224static int stm32_usbphyc_phy_exit(struct phy *phy)
225{
226 struct stm32_usbphyc_phy *usbphyc_phy = phy_get_drvdata(phy);
227 struct stm32_usbphyc *usbphyc = usbphyc_phy->usbphyc;
228
229 usbphyc_phy->active = false;
230
231 return stm32_usbphyc_pll_disable(usbphyc);
232}
233
234static int stm32_usbphyc_phy_power_on(struct phy *phy)
235{
236 struct stm32_usbphyc_phy *usbphyc_phy = phy_get_drvdata(phy);
237
238 return regulator_bulk_enable(NUM_SUPPLIES, usbphyc_phy->supplies);
239}
240
241static int stm32_usbphyc_phy_power_off(struct phy *phy)
242{
243 struct stm32_usbphyc_phy *usbphyc_phy = phy_get_drvdata(phy);
244
245 return regulator_bulk_disable(NUM_SUPPLIES, usbphyc_phy->supplies);
246}
247
248static const struct phy_ops stm32_usbphyc_phy_ops = {
249 .init = stm32_usbphyc_phy_init,
250 .exit = stm32_usbphyc_phy_exit,
251 .power_on = stm32_usbphyc_phy_power_on,
252 .power_off = stm32_usbphyc_phy_power_off,
253 .owner = THIS_MODULE,
254};
255
256static void stm32_usbphyc_switch_setup(struct stm32_usbphyc *usbphyc,
257 u32 utmi_switch)
258{
259 if (!utmi_switch)
260 stm32_usbphyc_clr_bits(usbphyc->base + STM32_USBPHYC_MISC,
261 SWITHOST);
262 else
263 stm32_usbphyc_set_bits(usbphyc->base + STM32_USBPHYC_MISC,
264 SWITHOST);
265 usbphyc->switch_setup = utmi_switch;
266}
267
268static struct phy *stm32_usbphyc_of_xlate(struct device *dev,
269 struct of_phandle_args *args)
270{
271 struct stm32_usbphyc *usbphyc = dev_get_drvdata(dev);
272 struct stm32_usbphyc_phy *usbphyc_phy = NULL;
273 struct device_node *phynode = args->np;
274
275 int port = 0;
276
277 for (port = 0; port < usbphyc->nphys; port++) {
278 if (phynode == usbphyc->phys[port]->phy->dev.of_node) {
279 usbphyc_phy = usbphyc->phys[port];
280 break;
281 }
282 }
283 if (!usbphyc_phy) {
284 dev_err(dev, "failed to find phy\n");
285 return ERR_PTR(-EINVAL);
286 }
287
288 if (((usbphyc_phy->index == 0) && (args->args_count != 0)) ||
289 ((usbphyc_phy->index == 1) && (args->args_count != 1))) {
290 dev_err(dev, "invalid number of cells for phy port%d\n",
291 usbphyc_phy->index);
292 return ERR_PTR(-EINVAL);
293 }
294
295 /* Configure the UTMI switch for PHY port#2 */
296 if (usbphyc_phy->index == 1) {
297 if (usbphyc->switch_setup < 0) {
298 stm32_usbphyc_switch_setup(usbphyc, args->args[0]);
299 } else {
300 if (args->args[0] != usbphyc->switch_setup) {
301 dev_err(dev, "phy port1 already used\n");
302 return ERR_PTR(-EBUSY);
303 }
304 }
305 }
306
307 return usbphyc_phy->phy;
308}
309
310static int stm32_usbphyc_probe(struct platform_device *pdev)
311{
312 struct stm32_usbphyc *usbphyc;
313 struct device *dev = &pdev->dev;
314 struct device_node *child, *np = dev->of_node;
315 struct resource *res;
316 struct phy_provider *phy_provider;
317 u32 version;
318 int ret, port = 0;
319
320 usbphyc = devm_kzalloc(dev, sizeof(*usbphyc), GFP_KERNEL);
321 if (!usbphyc)
322 return -ENOMEM;
323 usbphyc->dev = dev;
324 dev_set_drvdata(dev, usbphyc);
325
326 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
327 usbphyc->base = devm_ioremap_resource(dev, res);
328 if (IS_ERR(usbphyc->base))
329 return PTR_ERR(usbphyc->base);
330
331 usbphyc->clk = devm_clk_get(dev, 0);
332 if (IS_ERR(usbphyc->clk)) {
333 ret = PTR_ERR(usbphyc->clk);
334 dev_err(dev, "clk get failed: %d\n", ret);
335 return ret;
336 }
337
338 ret = clk_prepare_enable(usbphyc->clk);
339 if (ret) {
340 dev_err(dev, "clk enable failed: %d\n", ret);
341 return ret;
342 }
343
344 usbphyc->rst = devm_reset_control_get(dev, 0);
345 if (!IS_ERR(usbphyc->rst)) {
346 reset_control_assert(usbphyc->rst);
347 udelay(2);
348 reset_control_deassert(usbphyc->rst);
349 }
350
351 usbphyc->switch_setup = -EINVAL;
352 usbphyc->nphys = of_get_child_count(np);
353 usbphyc->phys = devm_kcalloc(dev, usbphyc->nphys,
354 sizeof(*usbphyc->phys), GFP_KERNEL);
355 if (!usbphyc->phys) {
356 ret = -ENOMEM;
357 goto clk_disable;
358 }
359
360 for_each_child_of_node(np, child) {
361 struct stm32_usbphyc_phy *usbphyc_phy;
362 struct phy *phy;
363 u32 index;
364 int i;
365
366 phy = devm_phy_create(dev, child, &stm32_usbphyc_phy_ops);
367 if (IS_ERR(phy)) {
368 ret = PTR_ERR(phy);
369 if (ret != -EPROBE_DEFER)
370 dev_err(dev,
371 "failed to create phy%d: %d\n", i, ret);
372 goto put_child;
373 }
374
375 usbphyc_phy = devm_kzalloc(dev, sizeof(*usbphyc_phy),
376 GFP_KERNEL);
377 if (!usbphyc_phy) {
378 ret = -ENOMEM;
379 goto put_child;
380 }
381
382 for (i = 0; i < NUM_SUPPLIES; i++)
383 usbphyc_phy->supplies[i].supply = supplies_names[i];
384
385 ret = devm_regulator_bulk_get(&phy->dev, NUM_SUPPLIES,
386 usbphyc_phy->supplies);
387 if (ret) {
388 if (ret != -EPROBE_DEFER)
389 dev_err(&phy->dev,
390 "failed to get regulators: %d\n", ret);
391 goto put_child;
392 }
393
394 ret = of_property_read_u32(child, "reg", &index);
395 if (ret || index > usbphyc->nphys) {
396 dev_err(&phy->dev, "invalid reg property: %d\n", ret);
397 goto put_child;
398 }
399
400 usbphyc->phys[port] = usbphyc_phy;
401 phy_set_bus_width(phy, 8);
402 phy_set_drvdata(phy, usbphyc_phy);
403
404 usbphyc->phys[port]->phy = phy;
405 usbphyc->phys[port]->usbphyc = usbphyc;
406 usbphyc->phys[port]->index = index;
407 usbphyc->phys[port]->active = false;
408
409 port++;
410 }
411
412 phy_provider = devm_of_phy_provider_register(dev,
413 stm32_usbphyc_of_xlate);
414 if (IS_ERR(phy_provider)) {
415 ret = PTR_ERR(phy_provider);
416 dev_err(dev, "failed to register phy provider: %d\n", ret);
417 goto clk_disable;
418 }
419
420 version = readl_relaxed(usbphyc->base + STM32_USBPHYC_VERSION);
421 dev_info(dev, "registered rev:%lu.%lu\n",
422 FIELD_GET(MAJREV, version), FIELD_GET(MINREV, version));
423
424 return 0;
425
426put_child:
427 of_node_put(child);
428clk_disable:
429 clk_disable_unprepare(usbphyc->clk);
430
431 return ret;
432}
433
434static int stm32_usbphyc_remove(struct platform_device *pdev)
435{
436 struct stm32_usbphyc *usbphyc = dev_get_drvdata(&pdev->dev);
437
438 clk_disable_unprepare(usbphyc->clk);
439
440 return 0;
441}
442
443static const struct of_device_id stm32_usbphyc_of_match[] = {
444 { .compatible = "st,stm32mp1-usbphyc", },
445 { },
446};
447MODULE_DEVICE_TABLE(of, stm32_usbphyc_of_match);
448
449static struct platform_driver stm32_usbphyc_driver = {
450 .probe = stm32_usbphyc_probe,
451 .remove = stm32_usbphyc_remove,
452 .driver = {
453 .of_match_table = stm32_usbphyc_of_match,
454 .name = "stm32-usbphyc",
455 }
456};
457module_platform_driver(stm32_usbphyc_driver);
458
459MODULE_DESCRIPTION("STMicroelectronics STM32 USBPHYC driver");
460MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@st.com>");
461MODULE_LICENSE("GPL v2");