1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Renesas R-Car Gen2 PHY driver
4  *
5  * Copyright (C) 2014 Renesas Solutions Corp.
6  * Copyright (C) 2014 Cogent Embedded, Inc.
7  * Copyright (C) 2019 Renesas Electronics Corp.
8  */
9 
10 #include <linux/clk.h>
11 #include <linux/delay.h>
12 #include <linux/io.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/phy/phy.h>
16 #include <linux/platform_device.h>
17 #include <linux/spinlock.h>
18 #include <linux/atomic.h>
19 #include <linux/of_device.h>
20 
21 #define USBHS_LPSTS			0x02
22 #define USBHS_UGCTRL			0x80
23 #define USBHS_UGCTRL2			0x84
24 #define USBHS_UGSTS			0x88	/* From technical update */
25 
26 /* Low Power Status register (LPSTS) */
27 #define USBHS_LPSTS_SUSPM		0x4000
28 
29 /* USB General control register (UGCTRL) */
30 #define USBHS_UGCTRL_CONNECT		0x00000004
31 #define USBHS_UGCTRL_PLLRESET		0x00000001
32 
33 /* USB General control register 2 (UGCTRL2) */
34 #define USBHS_UGCTRL2_USB2SEL		0x80000000
35 #define USBHS_UGCTRL2_USB2SEL_PCI	0x00000000
36 #define USBHS_UGCTRL2_USB2SEL_USB30	0x80000000
37 #define USBHS_UGCTRL2_USB0SEL		0x00000030
38 #define USBHS_UGCTRL2_USB0SEL_PCI	0x00000010
39 #define USBHS_UGCTRL2_USB0SEL_HS_USB	0x00000030
40 #define USBHS_UGCTRL2_USB0SEL_USB20	0x00000010
41 #define USBHS_UGCTRL2_USB0SEL_HS_USB20	0x00000020
42 
43 /* USB General status register (UGSTS) */
44 #define USBHS_UGSTS_LOCK		0x00000100 /* From technical update */
45 
46 #define PHYS_PER_CHANNEL	2
47 
48 struct rcar_gen2_phy {
49 	struct phy *phy;
50 	struct rcar_gen2_channel *channel;
51 	int number;
52 	u32 select_value;
53 };
54 
55 struct rcar_gen2_channel {
56 	struct device_node *of_node;
57 	struct rcar_gen2_phy_driver *drv;
58 	struct rcar_gen2_phy phys[PHYS_PER_CHANNEL];
59 	int selected_phy;
60 	u32 select_mask;
61 };
62 
63 struct rcar_gen2_phy_driver {
64 	void __iomem *base;
65 	struct clk *clk;
66 	spinlock_t lock;
67 	int num_channels;
68 	struct rcar_gen2_channel *channels;
69 };
70 
71 struct rcar_gen2_phy_data {
72 	const struct phy_ops *gen2_phy_ops;
73 	const u32 (*select_value)[PHYS_PER_CHANNEL];
74 	const u32 num_channels;
75 };
76 
77 static int rcar_gen2_phy_init(struct phy *p)
78 {
79 	struct rcar_gen2_phy *phy = phy_get_drvdata(p);
80 	struct rcar_gen2_channel *channel = phy->channel;
81 	struct rcar_gen2_phy_driver *drv = channel->drv;
82 	unsigned long flags;
83 	u32 ugctrl2;
84 
85 	/*
86 	 * Try to acquire exclusive access to PHY.  The first driver calling
87 	 * phy_init()  on a given channel wins, and all attempts  to use another
88 	 * PHY on this channel will fail until phy_exit() is called by the first
89 	 * driver.   Achieving this with cmpxcgh() should be SMP-safe.
90 	 */
91 	if (cmpxchg(&channel->selected_phy, -1, phy->number) != -1)
92 		return -EBUSY;
93 
94 	clk_prepare_enable(drv->clk);
95 
96 	spin_lock_irqsave(&drv->lock, flags);
97 	ugctrl2 = readl(drv->base + USBHS_UGCTRL2);
98 	ugctrl2 &= ~channel->select_mask;
99 	ugctrl2 |= phy->select_value;
100 	writel(ugctrl2, drv->base + USBHS_UGCTRL2);
101 	spin_unlock_irqrestore(&drv->lock, flags);
102 	return 0;
103 }
104 
105 static int rcar_gen2_phy_exit(struct phy *p)
106 {
107 	struct rcar_gen2_phy *phy = phy_get_drvdata(p);
108 	struct rcar_gen2_channel *channel = phy->channel;
109 
110 	clk_disable_unprepare(channel->drv->clk);
111 
112 	channel->selected_phy = -1;
113 
114 	return 0;
115 }
116 
117 static int rcar_gen2_phy_power_on(struct phy *p)
118 {
119 	struct rcar_gen2_phy *phy = phy_get_drvdata(p);
120 	struct rcar_gen2_phy_driver *drv = phy->channel->drv;
121 	void __iomem *base = drv->base;
122 	unsigned long flags;
123 	u32 value;
124 	int err = 0, i;
125 
126 	/* Skip if it's not USBHS */
127 	if (phy->select_value != USBHS_UGCTRL2_USB0SEL_HS_USB)
128 		return 0;
129 
130 	spin_lock_irqsave(&drv->lock, flags);
131 
132 	/* Power on USBHS PHY */
133 	value = readl(base + USBHS_UGCTRL);
134 	value &= ~USBHS_UGCTRL_PLLRESET;
135 	writel(value, base + USBHS_UGCTRL);
136 
137 	value = readw(base + USBHS_LPSTS);
138 	value |= USBHS_LPSTS_SUSPM;
139 	writew(value, base + USBHS_LPSTS);
140 
141 	for (i = 0; i < 20; i++) {
142 		value = readl(base + USBHS_UGSTS);
143 		if ((value & USBHS_UGSTS_LOCK) == USBHS_UGSTS_LOCK) {
144 			value = readl(base + USBHS_UGCTRL);
145 			value |= USBHS_UGCTRL_CONNECT;
146 			writel(value, base + USBHS_UGCTRL);
147 			goto out;
148 		}
149 		udelay(1);
150 	}
151 
152 	/* Timed out waiting for the PLL lock */
153 	err = -ETIMEDOUT;
154 
155 out:
156 	spin_unlock_irqrestore(&drv->lock, flags);
157 
158 	return err;
159 }
160 
161 static int rcar_gen2_phy_power_off(struct phy *p)
162 {
163 	struct rcar_gen2_phy *phy = phy_get_drvdata(p);
164 	struct rcar_gen2_phy_driver *drv = phy->channel->drv;
165 	void __iomem *base = drv->base;
166 	unsigned long flags;
167 	u32 value;
168 
169 	/* Skip if it's not USBHS */
170 	if (phy->select_value != USBHS_UGCTRL2_USB0SEL_HS_USB)
171 		return 0;
172 
173 	spin_lock_irqsave(&drv->lock, flags);
174 
175 	/* Power off USBHS PHY */
176 	value = readl(base + USBHS_UGCTRL);
177 	value &= ~USBHS_UGCTRL_CONNECT;
178 	writel(value, base + USBHS_UGCTRL);
179 
180 	value = readw(base + USBHS_LPSTS);
181 	value &= ~USBHS_LPSTS_SUSPM;
182 	writew(value, base + USBHS_LPSTS);
183 
184 	value = readl(base + USBHS_UGCTRL);
185 	value |= USBHS_UGCTRL_PLLRESET;
186 	writel(value, base + USBHS_UGCTRL);
187 
188 	spin_unlock_irqrestore(&drv->lock, flags);
189 
190 	return 0;
191 }
192 
193 static int rz_g1c_phy_power_on(struct phy *p)
194 {
195 	struct rcar_gen2_phy *phy = phy_get_drvdata(p);
196 	struct rcar_gen2_phy_driver *drv = phy->channel->drv;
197 	void __iomem *base = drv->base;
198 	unsigned long flags;
199 	u32 value;
200 
201 	spin_lock_irqsave(&drv->lock, flags);
202 
203 	/* Power on USBHS PHY */
204 	value = readl(base + USBHS_UGCTRL);
205 	value &= ~USBHS_UGCTRL_PLLRESET;
206 	writel(value, base + USBHS_UGCTRL);
207 
208 	/* As per the data sheet wait 340 micro sec for power stable */
209 	udelay(340);
210 
211 	if (phy->select_value == USBHS_UGCTRL2_USB0SEL_HS_USB20) {
212 		value = readw(base + USBHS_LPSTS);
213 		value |= USBHS_LPSTS_SUSPM;
214 		writew(value, base + USBHS_LPSTS);
215 	}
216 
217 	spin_unlock_irqrestore(&drv->lock, flags);
218 
219 	return 0;
220 }
221 
222 static int rz_g1c_phy_power_off(struct phy *p)
223 {
224 	struct rcar_gen2_phy *phy = phy_get_drvdata(p);
225 	struct rcar_gen2_phy_driver *drv = phy->channel->drv;
226 	void __iomem *base = drv->base;
227 	unsigned long flags;
228 	u32 value;
229 
230 	spin_lock_irqsave(&drv->lock, flags);
231 	/* Power off USBHS PHY */
232 	if (phy->select_value == USBHS_UGCTRL2_USB0SEL_HS_USB20) {
233 		value = readw(base + USBHS_LPSTS);
234 		value &= ~USBHS_LPSTS_SUSPM;
235 		writew(value, base + USBHS_LPSTS);
236 	}
237 
238 	value = readl(base + USBHS_UGCTRL);
239 	value |= USBHS_UGCTRL_PLLRESET;
240 	writel(value, base + USBHS_UGCTRL);
241 
242 	spin_unlock_irqrestore(&drv->lock, flags);
243 
244 	return 0;
245 }
246 
247 static const struct phy_ops rcar_gen2_phy_ops = {
248 	.init		= rcar_gen2_phy_init,
249 	.exit		= rcar_gen2_phy_exit,
250 	.power_on	= rcar_gen2_phy_power_on,
251 	.power_off	= rcar_gen2_phy_power_off,
252 	.owner		= THIS_MODULE,
253 };
254 
255 static const struct phy_ops rz_g1c_phy_ops = {
256 	.init		= rcar_gen2_phy_init,
257 	.exit		= rcar_gen2_phy_exit,
258 	.power_on	= rz_g1c_phy_power_on,
259 	.power_off	= rz_g1c_phy_power_off,
260 	.owner		= THIS_MODULE,
261 };
262 
263 static const u32 pci_select_value[][PHYS_PER_CHANNEL] = {
264 	[0]	= { USBHS_UGCTRL2_USB0SEL_PCI, USBHS_UGCTRL2_USB0SEL_HS_USB },
265 	[2]	= { USBHS_UGCTRL2_USB2SEL_PCI, USBHS_UGCTRL2_USB2SEL_USB30 },
266 };
267 
268 static const u32 usb20_select_value[][PHYS_PER_CHANNEL] = {
269 	{ USBHS_UGCTRL2_USB0SEL_USB20, USBHS_UGCTRL2_USB0SEL_HS_USB20 },
270 };
271 
272 static const struct rcar_gen2_phy_data rcar_gen2_usb_phy_data = {
273 	.gen2_phy_ops = &rcar_gen2_phy_ops,
274 	.select_value = pci_select_value,
275 	.num_channels = ARRAY_SIZE(pci_select_value),
276 };
277 
278 static const struct rcar_gen2_phy_data rz_g1c_usb_phy_data = {
279 	.gen2_phy_ops = &rz_g1c_phy_ops,
280 	.select_value = usb20_select_value,
281 	.num_channels = ARRAY_SIZE(usb20_select_value),
282 };
283 
284 static const struct of_device_id rcar_gen2_phy_match_table[] = {
285 	{
286 		.compatible = "renesas,usb-phy-r8a77470",
287 		.data = &rz_g1c_usb_phy_data,
288 	},
289 	{
290 		.compatible = "renesas,usb-phy-r8a7790",
291 		.data = &rcar_gen2_usb_phy_data,
292 	},
293 	{
294 		.compatible = "renesas,usb-phy-r8a7791",
295 		.data = &rcar_gen2_usb_phy_data,
296 	},
297 	{
298 		.compatible = "renesas,usb-phy-r8a7794",
299 		.data = &rcar_gen2_usb_phy_data,
300 	},
301 	{
302 		.compatible = "renesas,rcar-gen2-usb-phy",
303 		.data = &rcar_gen2_usb_phy_data,
304 	},
305 	{ /* sentinel */ },
306 };
307 MODULE_DEVICE_TABLE(of, rcar_gen2_phy_match_table);
308 
309 static struct phy *rcar_gen2_phy_xlate(struct device *dev,
310 				       struct of_phandle_args *args)
311 {
312 	struct rcar_gen2_phy_driver *drv;
313 	struct device_node *np = args->np;
314 	int i;
315 
316 	drv = dev_get_drvdata(dev);
317 	if (!drv)
318 		return ERR_PTR(-EINVAL);
319 
320 	for (i = 0; i < drv->num_channels; i++) {
321 		if (np == drv->channels[i].of_node)
322 			break;
323 	}
324 
325 	if (i >= drv->num_channels || args->args[0] >= 2)
326 		return ERR_PTR(-ENODEV);
327 
328 	return drv->channels[i].phys[args->args[0]].phy;
329 }
330 
331 static const u32 select_mask[] = {
332 	[0]	= USBHS_UGCTRL2_USB0SEL,
333 	[2]	= USBHS_UGCTRL2_USB2SEL,
334 };
335 
336 static int rcar_gen2_phy_probe(struct platform_device *pdev)
337 {
338 	struct device *dev = &pdev->dev;
339 	struct rcar_gen2_phy_driver *drv;
340 	struct phy_provider *provider;
341 	struct device_node *np;
342 	struct resource *res;
343 	void __iomem *base;
344 	struct clk *clk;
345 	const struct rcar_gen2_phy_data *data;
346 	int i = 0;
347 
348 	if (!dev->of_node) {
349 		dev_err(dev,
350 			"This driver is required to be instantiated from device tree\n");
351 		return -EINVAL;
352 	}
353 
354 	clk = devm_clk_get(dev, "usbhs");
355 	if (IS_ERR(clk)) {
356 		dev_err(dev, "Can't get USBHS clock\n");
357 		return PTR_ERR(clk);
358 	}
359 
360 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
361 	base = devm_ioremap_resource(dev, res);
362 	if (IS_ERR(base))
363 		return PTR_ERR(base);
364 
365 	drv = devm_kzalloc(dev, sizeof(*drv), GFP_KERNEL);
366 	if (!drv)
367 		return -ENOMEM;
368 
369 	spin_lock_init(&drv->lock);
370 
371 	drv->clk = clk;
372 	drv->base = base;
373 
374 	data = of_device_get_match_data(dev);
375 	if (!data)
376 		return -EINVAL;
377 
378 	drv->num_channels = of_get_child_count(dev->of_node);
379 	drv->channels = devm_kcalloc(dev, drv->num_channels,
380 				     sizeof(struct rcar_gen2_channel),
381 				     GFP_KERNEL);
382 	if (!drv->channels)
383 		return -ENOMEM;
384 
385 	for_each_child_of_node(dev->of_node, np) {
386 		struct rcar_gen2_channel *channel = drv->channels + i;
387 		u32 channel_num;
388 		int error, n;
389 
390 		channel->of_node = np;
391 		channel->drv = drv;
392 		channel->selected_phy = -1;
393 
394 		error = of_property_read_u32(np, "reg", &channel_num);
395 		if (error || channel_num >= data->num_channels) {
396 			dev_err(dev, "Invalid \"reg\" property\n");
397 			of_node_put(np);
398 			return error;
399 		}
400 		channel->select_mask = select_mask[channel_num];
401 
402 		for (n = 0; n < PHYS_PER_CHANNEL; n++) {
403 			struct rcar_gen2_phy *phy = &channel->phys[n];
404 
405 			phy->channel = channel;
406 			phy->number = n;
407 			phy->select_value = data->select_value[channel_num][n];
408 
409 			phy->phy = devm_phy_create(dev, NULL,
410 						   data->gen2_phy_ops);
411 			if (IS_ERR(phy->phy)) {
412 				dev_err(dev, "Failed to create PHY\n");
413 				of_node_put(np);
414 				return PTR_ERR(phy->phy);
415 			}
416 			phy_set_drvdata(phy->phy, phy);
417 		}
418 
419 		i++;
420 	}
421 
422 	provider = devm_of_phy_provider_register(dev, rcar_gen2_phy_xlate);
423 	if (IS_ERR(provider)) {
424 		dev_err(dev, "Failed to register PHY provider\n");
425 		return PTR_ERR(provider);
426 	}
427 
428 	dev_set_drvdata(dev, drv);
429 
430 	return 0;
431 }
432 
433 static struct platform_driver rcar_gen2_phy_driver = {
434 	.driver = {
435 		.name		= "phy_rcar_gen2",
436 		.of_match_table	= rcar_gen2_phy_match_table,
437 	},
438 	.probe	= rcar_gen2_phy_probe,
439 };
440 
441 module_platform_driver(rcar_gen2_phy_driver);
442 
443 MODULE_LICENSE("GPL v2");
444 MODULE_DESCRIPTION("Renesas R-Car Gen2 PHY");
445 MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>");
446