1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Renesas R-Car Gen3 for USB2.0 PHY driver
4  *
5  * Copyright (C) 2015-2017 Renesas Electronics Corporation
6  *
7  * This is based on the phy-rcar-gen2 driver:
8  * Copyright (C) 2014 Renesas Solutions Corp.
9  * Copyright (C) 2014 Cogent Embedded, Inc.
10  */
11 
12 #include <linux/extcon-provider.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/of_address.h>
18 #include <linux/of_device.h>
19 #include <linux/phy/phy.h>
20 #include <linux/platform_device.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/regulator/consumer.h>
23 #include <linux/usb/of.h>
24 #include <linux/workqueue.h>
25 
26 /******* USB2.0 Host registers (original offset is +0x200) *******/
27 #define USB2_INT_ENABLE		0x000
28 #define USB2_USBCTR		0x00c
29 #define USB2_SPD_RSM_TIMSET	0x10c
30 #define USB2_OC_TIMSET		0x110
31 #define USB2_COMMCTRL		0x600
32 #define USB2_OBINTSTA		0x604
33 #define USB2_OBINTEN		0x608
34 #define USB2_VBCTRL		0x60c
35 #define USB2_LINECTRL1		0x610
36 #define USB2_ADPCTRL		0x630
37 
38 /* INT_ENABLE */
39 #define USB2_INT_ENABLE_UCOM_INTEN	BIT(3)
40 #define USB2_INT_ENABLE_USBH_INTB_EN	BIT(2)
41 #define USB2_INT_ENABLE_USBH_INTA_EN	BIT(1)
42 #define USB2_INT_ENABLE_INIT		(USB2_INT_ENABLE_UCOM_INTEN | \
43 					 USB2_INT_ENABLE_USBH_INTB_EN | \
44 					 USB2_INT_ENABLE_USBH_INTA_EN)
45 
46 /* USBCTR */
47 #define USB2_USBCTR_DIRPD	BIT(2)
48 #define USB2_USBCTR_PLL_RST	BIT(1)
49 
50 /* SPD_RSM_TIMSET */
51 #define USB2_SPD_RSM_TIMSET_INIT	0x014e029b
52 
53 /* OC_TIMSET */
54 #define USB2_OC_TIMSET_INIT		0x000209ab
55 
56 /* COMMCTRL */
57 #define USB2_COMMCTRL_OTG_PERI		BIT(31)	/* 1 = Peripheral mode */
58 
59 /* OBINTSTA and OBINTEN */
60 #define USB2_OBINT_SESSVLDCHG		BIT(12)
61 #define USB2_OBINT_IDDIGCHG		BIT(11)
62 #define USB2_OBINT_BITS			(USB2_OBINT_SESSVLDCHG | \
63 					 USB2_OBINT_IDDIGCHG)
64 
65 /* VBCTRL */
66 #define USB2_VBCTRL_DRVVBUSSEL		BIT(8)
67 
68 /* LINECTRL1 */
69 #define USB2_LINECTRL1_DPRPD_EN		BIT(19)
70 #define USB2_LINECTRL1_DP_RPD		BIT(18)
71 #define USB2_LINECTRL1_DMRPD_EN		BIT(17)
72 #define USB2_LINECTRL1_DM_RPD		BIT(16)
73 #define USB2_LINECTRL1_OPMODE_NODRV	BIT(6)
74 
75 /* ADPCTRL */
76 #define USB2_ADPCTRL_OTGSESSVLD		BIT(20)
77 #define USB2_ADPCTRL_IDDIG		BIT(19)
78 #define USB2_ADPCTRL_IDPULLUP		BIT(5)	/* 1 = ID sampling is enabled */
79 #define USB2_ADPCTRL_DRVVBUS		BIT(4)
80 
81 struct rcar_gen3_chan {
82 	void __iomem *base;
83 	struct extcon_dev *extcon;
84 	struct phy *phy;
85 	struct regulator *vbus;
86 	struct work_struct work;
87 	enum usb_dr_mode dr_mode;
88 	bool extcon_host;
89 	bool is_otg_channel;
90 	bool uses_otg_pins;
91 };
92 
93 /*
94  * Combination about is_otg_channel and uses_otg_pins:
95  *
96  * Parameters				|| Behaviors
97  * is_otg_channel	| uses_otg_pins	|| irqs		| role sysfs
98  * ---------------------+---------------++--------------+------------
99  * true			| true		|| enabled	| enabled
100  * true                 | false		|| disabled	| enabled
101  * false                | any		|| disabled	| disabled
102  */
103 
104 static void rcar_gen3_phy_usb2_work(struct work_struct *work)
105 {
106 	struct rcar_gen3_chan *ch = container_of(work, struct rcar_gen3_chan,
107 						 work);
108 
109 	if (ch->extcon_host) {
110 		extcon_set_state_sync(ch->extcon, EXTCON_USB_HOST, true);
111 		extcon_set_state_sync(ch->extcon, EXTCON_USB, false);
112 	} else {
113 		extcon_set_state_sync(ch->extcon, EXTCON_USB_HOST, false);
114 		extcon_set_state_sync(ch->extcon, EXTCON_USB, true);
115 	}
116 }
117 
118 static void rcar_gen3_set_host_mode(struct rcar_gen3_chan *ch, int host)
119 {
120 	void __iomem *usb2_base = ch->base;
121 	u32 val = readl(usb2_base + USB2_COMMCTRL);
122 
123 	dev_vdbg(&ch->phy->dev, "%s: %08x, %d\n", __func__, val, host);
124 	if (host)
125 		val &= ~USB2_COMMCTRL_OTG_PERI;
126 	else
127 		val |= USB2_COMMCTRL_OTG_PERI;
128 	writel(val, usb2_base + USB2_COMMCTRL);
129 }
130 
131 static void rcar_gen3_set_linectrl(struct rcar_gen3_chan *ch, int dp, int dm)
132 {
133 	void __iomem *usb2_base = ch->base;
134 	u32 val = readl(usb2_base + USB2_LINECTRL1);
135 
136 	dev_vdbg(&ch->phy->dev, "%s: %08x, %d, %d\n", __func__, val, dp, dm);
137 	val &= ~(USB2_LINECTRL1_DP_RPD | USB2_LINECTRL1_DM_RPD);
138 	if (dp)
139 		val |= USB2_LINECTRL1_DP_RPD;
140 	if (dm)
141 		val |= USB2_LINECTRL1_DM_RPD;
142 	writel(val, usb2_base + USB2_LINECTRL1);
143 }
144 
145 static void rcar_gen3_enable_vbus_ctrl(struct rcar_gen3_chan *ch, int vbus)
146 {
147 	void __iomem *usb2_base = ch->base;
148 	u32 val = readl(usb2_base + USB2_ADPCTRL);
149 
150 	dev_vdbg(&ch->phy->dev, "%s: %08x, %d\n", __func__, val, vbus);
151 	if (vbus)
152 		val |= USB2_ADPCTRL_DRVVBUS;
153 	else
154 		val &= ~USB2_ADPCTRL_DRVVBUS;
155 	writel(val, usb2_base + USB2_ADPCTRL);
156 }
157 
158 static void rcar_gen3_control_otg_irq(struct rcar_gen3_chan *ch, int enable)
159 {
160 	void __iomem *usb2_base = ch->base;
161 	u32 val = readl(usb2_base + USB2_OBINTEN);
162 
163 	if (ch->uses_otg_pins && enable)
164 		val |= USB2_OBINT_BITS;
165 	else
166 		val &= ~USB2_OBINT_BITS;
167 	writel(val, usb2_base + USB2_OBINTEN);
168 }
169 
170 static void rcar_gen3_init_for_host(struct rcar_gen3_chan *ch)
171 {
172 	rcar_gen3_set_linectrl(ch, 1, 1);
173 	rcar_gen3_set_host_mode(ch, 1);
174 	rcar_gen3_enable_vbus_ctrl(ch, 1);
175 
176 	ch->extcon_host = true;
177 	schedule_work(&ch->work);
178 }
179 
180 static void rcar_gen3_init_for_peri(struct rcar_gen3_chan *ch)
181 {
182 	rcar_gen3_set_linectrl(ch, 0, 1);
183 	rcar_gen3_set_host_mode(ch, 0);
184 	rcar_gen3_enable_vbus_ctrl(ch, 0);
185 
186 	ch->extcon_host = false;
187 	schedule_work(&ch->work);
188 }
189 
190 static void rcar_gen3_init_for_b_host(struct rcar_gen3_chan *ch)
191 {
192 	void __iomem *usb2_base = ch->base;
193 	u32 val;
194 
195 	val = readl(usb2_base + USB2_LINECTRL1);
196 	writel(val | USB2_LINECTRL1_OPMODE_NODRV, usb2_base + USB2_LINECTRL1);
197 
198 	rcar_gen3_set_linectrl(ch, 1, 1);
199 	rcar_gen3_set_host_mode(ch, 1);
200 	rcar_gen3_enable_vbus_ctrl(ch, 0);
201 
202 	val = readl(usb2_base + USB2_LINECTRL1);
203 	writel(val & ~USB2_LINECTRL1_OPMODE_NODRV, usb2_base + USB2_LINECTRL1);
204 }
205 
206 static void rcar_gen3_init_for_a_peri(struct rcar_gen3_chan *ch)
207 {
208 	rcar_gen3_set_linectrl(ch, 0, 1);
209 	rcar_gen3_set_host_mode(ch, 0);
210 	rcar_gen3_enable_vbus_ctrl(ch, 1);
211 }
212 
213 static void rcar_gen3_init_from_a_peri_to_a_host(struct rcar_gen3_chan *ch)
214 {
215 	rcar_gen3_control_otg_irq(ch, 0);
216 
217 	rcar_gen3_enable_vbus_ctrl(ch, 1);
218 	rcar_gen3_init_for_host(ch);
219 
220 	rcar_gen3_control_otg_irq(ch, 1);
221 }
222 
223 static bool rcar_gen3_check_id(struct rcar_gen3_chan *ch)
224 {
225 	if (!ch->uses_otg_pins)
226 		return (ch->dr_mode == USB_DR_MODE_HOST) ? false : true;
227 
228 	return !!(readl(ch->base + USB2_ADPCTRL) & USB2_ADPCTRL_IDDIG);
229 }
230 
231 static void rcar_gen3_device_recognition(struct rcar_gen3_chan *ch)
232 {
233 	if (!rcar_gen3_check_id(ch))
234 		rcar_gen3_init_for_host(ch);
235 	else
236 		rcar_gen3_init_for_peri(ch);
237 }
238 
239 static bool rcar_gen3_is_host(struct rcar_gen3_chan *ch)
240 {
241 	return !(readl(ch->base + USB2_COMMCTRL) & USB2_COMMCTRL_OTG_PERI);
242 }
243 
244 static enum phy_mode rcar_gen3_get_phy_mode(struct rcar_gen3_chan *ch)
245 {
246 	if (rcar_gen3_is_host(ch))
247 		return PHY_MODE_USB_HOST;
248 
249 	return PHY_MODE_USB_DEVICE;
250 }
251 
252 static ssize_t role_store(struct device *dev, struct device_attribute *attr,
253 			  const char *buf, size_t count)
254 {
255 	struct rcar_gen3_chan *ch = dev_get_drvdata(dev);
256 	bool is_b_device;
257 	enum phy_mode cur_mode, new_mode;
258 
259 	if (!ch->is_otg_channel || !ch->phy->init_count)
260 		return -EIO;
261 
262 	if (!strncmp(buf, "host", strlen("host")))
263 		new_mode = PHY_MODE_USB_HOST;
264 	else if (!strncmp(buf, "peripheral", strlen("peripheral")))
265 		new_mode = PHY_MODE_USB_DEVICE;
266 	else
267 		return -EINVAL;
268 
269 	/* is_b_device: true is B-Device. false is A-Device. */
270 	is_b_device = rcar_gen3_check_id(ch);
271 	cur_mode = rcar_gen3_get_phy_mode(ch);
272 
273 	/* If current and new mode is the same, this returns the error */
274 	if (cur_mode == new_mode)
275 		return -EINVAL;
276 
277 	if (new_mode == PHY_MODE_USB_HOST) { /* And is_host must be false */
278 		if (!is_b_device)	/* A-Peripheral */
279 			rcar_gen3_init_from_a_peri_to_a_host(ch);
280 		else			/* B-Peripheral */
281 			rcar_gen3_init_for_b_host(ch);
282 	} else {			/* And is_host must be true */
283 		if (!is_b_device)	/* A-Host */
284 			rcar_gen3_init_for_a_peri(ch);
285 		else			/* B-Host */
286 			rcar_gen3_init_for_peri(ch);
287 	}
288 
289 	return count;
290 }
291 
292 static ssize_t role_show(struct device *dev, struct device_attribute *attr,
293 			 char *buf)
294 {
295 	struct rcar_gen3_chan *ch = dev_get_drvdata(dev);
296 
297 	if (!ch->is_otg_channel || !ch->phy->init_count)
298 		return -EIO;
299 
300 	return sprintf(buf, "%s\n", rcar_gen3_is_host(ch) ? "host" :
301 							    "peripheral");
302 }
303 static DEVICE_ATTR_RW(role);
304 
305 static void rcar_gen3_init_otg(struct rcar_gen3_chan *ch)
306 {
307 	void __iomem *usb2_base = ch->base;
308 	u32 val;
309 
310 	/* Should not use functions of read-modify-write a register */
311 	val = readl(usb2_base + USB2_LINECTRL1);
312 	val = (val & ~USB2_LINECTRL1_DP_RPD) | USB2_LINECTRL1_DPRPD_EN |
313 	      USB2_LINECTRL1_DMRPD_EN | USB2_LINECTRL1_DM_RPD;
314 	writel(val, usb2_base + USB2_LINECTRL1);
315 
316 	val = readl(usb2_base + USB2_VBCTRL);
317 	writel(val | USB2_VBCTRL_DRVVBUSSEL, usb2_base + USB2_VBCTRL);
318 	val = readl(usb2_base + USB2_ADPCTRL);
319 	writel(val | USB2_ADPCTRL_IDPULLUP, usb2_base + USB2_ADPCTRL);
320 
321 	msleep(20);
322 
323 	writel(0xffffffff, usb2_base + USB2_OBINTSTA);
324 	writel(USB2_OBINT_BITS, usb2_base + USB2_OBINTEN);
325 
326 	rcar_gen3_device_recognition(ch);
327 }
328 
329 static int rcar_gen3_phy_usb2_init(struct phy *p)
330 {
331 	struct rcar_gen3_chan *channel = phy_get_drvdata(p);
332 	void __iomem *usb2_base = channel->base;
333 
334 	/* Initialize USB2 part */
335 	writel(USB2_INT_ENABLE_INIT, usb2_base + USB2_INT_ENABLE);
336 	writel(USB2_SPD_RSM_TIMSET_INIT, usb2_base + USB2_SPD_RSM_TIMSET);
337 	writel(USB2_OC_TIMSET_INIT, usb2_base + USB2_OC_TIMSET);
338 
339 	/* Initialize otg part */
340 	if (channel->is_otg_channel)
341 		rcar_gen3_init_otg(channel);
342 
343 	return 0;
344 }
345 
346 static int rcar_gen3_phy_usb2_exit(struct phy *p)
347 {
348 	struct rcar_gen3_chan *channel = phy_get_drvdata(p);
349 
350 	writel(0, channel->base + USB2_INT_ENABLE);
351 
352 	return 0;
353 }
354 
355 static int rcar_gen3_phy_usb2_power_on(struct phy *p)
356 {
357 	struct rcar_gen3_chan *channel = phy_get_drvdata(p);
358 	void __iomem *usb2_base = channel->base;
359 	u32 val;
360 	int ret;
361 
362 	if (channel->vbus) {
363 		ret = regulator_enable(channel->vbus);
364 		if (ret)
365 			return ret;
366 	}
367 
368 	val = readl(usb2_base + USB2_USBCTR);
369 	val |= USB2_USBCTR_PLL_RST;
370 	writel(val, usb2_base + USB2_USBCTR);
371 	val &= ~USB2_USBCTR_PLL_RST;
372 	writel(val, usb2_base + USB2_USBCTR);
373 
374 	return 0;
375 }
376 
377 static int rcar_gen3_phy_usb2_power_off(struct phy *p)
378 {
379 	struct rcar_gen3_chan *channel = phy_get_drvdata(p);
380 	int ret = 0;
381 
382 	if (channel->vbus)
383 		ret = regulator_disable(channel->vbus);
384 
385 	return ret;
386 }
387 
388 static const struct phy_ops rcar_gen3_phy_usb2_ops = {
389 	.init		= rcar_gen3_phy_usb2_init,
390 	.exit		= rcar_gen3_phy_usb2_exit,
391 	.power_on	= rcar_gen3_phy_usb2_power_on,
392 	.power_off	= rcar_gen3_phy_usb2_power_off,
393 	.owner		= THIS_MODULE,
394 };
395 
396 static irqreturn_t rcar_gen3_phy_usb2_irq(int irq, void *_ch)
397 {
398 	struct rcar_gen3_chan *ch = _ch;
399 	void __iomem *usb2_base = ch->base;
400 	u32 status = readl(usb2_base + USB2_OBINTSTA);
401 	irqreturn_t ret = IRQ_NONE;
402 
403 	if (status & USB2_OBINT_BITS) {
404 		dev_vdbg(&ch->phy->dev, "%s: %08x\n", __func__, status);
405 		writel(USB2_OBINT_BITS, usb2_base + USB2_OBINTSTA);
406 		rcar_gen3_device_recognition(ch);
407 		ret = IRQ_HANDLED;
408 	}
409 
410 	return ret;
411 }
412 
413 static const struct of_device_id rcar_gen3_phy_usb2_match_table[] = {
414 	{ .compatible = "renesas,usb2-phy-r8a7795" },
415 	{ .compatible = "renesas,usb2-phy-r8a7796" },
416 	{ .compatible = "renesas,usb2-phy-r8a77965" },
417 	{ .compatible = "renesas,rcar-gen3-usb2-phy" },
418 	{ }
419 };
420 MODULE_DEVICE_TABLE(of, rcar_gen3_phy_usb2_match_table);
421 
422 static const unsigned int rcar_gen3_phy_cable[] = {
423 	EXTCON_USB,
424 	EXTCON_USB_HOST,
425 	EXTCON_NONE,
426 };
427 
428 static int rcar_gen3_phy_usb2_probe(struct platform_device *pdev)
429 {
430 	struct device *dev = &pdev->dev;
431 	struct rcar_gen3_chan *channel;
432 	struct phy_provider *provider;
433 	struct resource *res;
434 	int irq, ret = 0;
435 
436 	if (!dev->of_node) {
437 		dev_err(dev, "This driver needs device tree\n");
438 		return -EINVAL;
439 	}
440 
441 	channel = devm_kzalloc(dev, sizeof(*channel), GFP_KERNEL);
442 	if (!channel)
443 		return -ENOMEM;
444 
445 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
446 	channel->base = devm_ioremap_resource(dev, res);
447 	if (IS_ERR(channel->base))
448 		return PTR_ERR(channel->base);
449 
450 	/* call request_irq for OTG */
451 	irq = platform_get_irq(pdev, 0);
452 	if (irq >= 0) {
453 		INIT_WORK(&channel->work, rcar_gen3_phy_usb2_work);
454 		irq = devm_request_irq(dev, irq, rcar_gen3_phy_usb2_irq,
455 				       IRQF_SHARED, dev_name(dev), channel);
456 		if (irq < 0)
457 			dev_err(dev, "No irq handler (%d)\n", irq);
458 	}
459 
460 	channel->dr_mode = of_usb_get_dr_mode_by_phy(dev->of_node, 0);
461 	if (channel->dr_mode != USB_DR_MODE_UNKNOWN) {
462 		int ret;
463 
464 		channel->is_otg_channel = true;
465 		channel->uses_otg_pins = !of_property_read_bool(dev->of_node,
466 							"renesas,no-otg-pins");
467 		channel->extcon = devm_extcon_dev_allocate(dev,
468 							rcar_gen3_phy_cable);
469 		if (IS_ERR(channel->extcon))
470 			return PTR_ERR(channel->extcon);
471 
472 		ret = devm_extcon_dev_register(dev, channel->extcon);
473 		if (ret < 0) {
474 			dev_err(dev, "Failed to register extcon\n");
475 			return ret;
476 		}
477 	}
478 
479 	/*
480 	 * devm_phy_create() will call pm_runtime_enable(&phy->dev);
481 	 * And then, phy-core will manage runtime pm for this device.
482 	 */
483 	pm_runtime_enable(dev);
484 	channel->phy = devm_phy_create(dev, NULL, &rcar_gen3_phy_usb2_ops);
485 	if (IS_ERR(channel->phy)) {
486 		dev_err(dev, "Failed to create USB2 PHY\n");
487 		ret = PTR_ERR(channel->phy);
488 		goto error;
489 	}
490 
491 	channel->vbus = devm_regulator_get_optional(dev, "vbus");
492 	if (IS_ERR(channel->vbus)) {
493 		if (PTR_ERR(channel->vbus) == -EPROBE_DEFER) {
494 			ret = PTR_ERR(channel->vbus);
495 			goto error;
496 		}
497 		channel->vbus = NULL;
498 	}
499 
500 	platform_set_drvdata(pdev, channel);
501 	phy_set_drvdata(channel->phy, channel);
502 
503 	provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
504 	if (IS_ERR(provider)) {
505 		dev_err(dev, "Failed to register PHY provider\n");
506 		ret = PTR_ERR(provider);
507 		goto error;
508 	} else if (channel->is_otg_channel) {
509 		int ret;
510 
511 		ret = device_create_file(dev, &dev_attr_role);
512 		if (ret < 0)
513 			goto error;
514 	}
515 
516 	return 0;
517 
518 error:
519 	pm_runtime_disable(dev);
520 
521 	return ret;
522 }
523 
524 static int rcar_gen3_phy_usb2_remove(struct platform_device *pdev)
525 {
526 	struct rcar_gen3_chan *channel = platform_get_drvdata(pdev);
527 
528 	if (channel->is_otg_channel)
529 		device_remove_file(&pdev->dev, &dev_attr_role);
530 
531 	pm_runtime_disable(&pdev->dev);
532 
533 	return 0;
534 };
535 
536 static struct platform_driver rcar_gen3_phy_usb2_driver = {
537 	.driver = {
538 		.name		= "phy_rcar_gen3_usb2",
539 		.of_match_table	= rcar_gen3_phy_usb2_match_table,
540 	},
541 	.probe	= rcar_gen3_phy_usb2_probe,
542 	.remove = rcar_gen3_phy_usb2_remove,
543 };
544 module_platform_driver(rcar_gen3_phy_usb2_driver);
545 
546 MODULE_LICENSE("GPL v2");
547 MODULE_DESCRIPTION("Renesas R-Car Gen3 USB 2.0 PHY");
548 MODULE_AUTHOR("Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>");
549