1 /*
2  * Copyright (C) 2017 Broadcom
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation version 2.
7  *
8  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
9  * kind, whether express or implied; without even the implied warranty
10  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  */
13 
14 #include <linux/delay.h>
15 #include <linux/extcon.h>
16 #include <linux/gpio.h>
17 #include <linux/gpio/consumer.h>
18 #include <linux/init.h>
19 #include <linux/interrupt.h>
20 #include <linux/io.h>
21 #include <linux/irq.h>
22 #include <linux/mfd/syscon.h>
23 #include <linux/module.h>
24 #include <linux/of.h>
25 #include <linux/of_address.h>
26 #include <linux/phy/phy.h>
27 #include <linux/platform_device.h>
28 #include <linux/regmap.h>
29 #include <linux/slab.h>
30 #include <linux/workqueue.h>
31 
32 #define ICFG_DRD_AFE		0x0
33 #define ICFG_MISC_STAT		0x18
34 #define ICFG_DRD_P0CTL		0x1C
35 #define ICFG_STRAP_CTRL		0x20
36 #define ICFG_FSM_CTRL		0x24
37 
38 #define ICFG_DEV_BIT		BIT(2)
39 #define IDM_RST_BIT		BIT(0)
40 #define AFE_CORERDY_VDDC	BIT(18)
41 #define PHY_PLL_RESETB		BIT(15)
42 #define PHY_RESETB		BIT(14)
43 #define PHY_PLL_LOCK		BIT(0)
44 
45 #define DRD_DEV_MODE		BIT(20)
46 #define OHCI_OVRCUR_POL		BIT(11)
47 #define ICFG_OFF_MODE		BIT(6)
48 #define PLL_LOCK_RETRY		1000
49 
50 #define EVT_DEVICE		0
51 #define EVT_HOST		1
52 
53 #define DRD_HOST_MODE		(BIT(2) | BIT(3))
54 #define DRD_DEVICE_MODE		(BIT(4) | BIT(5))
55 #define DRD_HOST_VAL		0x803
56 #define DRD_DEV_VAL		0x807
57 #define GPIO_DELAY		20
58 
59 struct ns2_phy_data;
60 struct ns2_phy_driver {
61 	void __iomem *icfgdrd_regs;
62 	void __iomem *idmdrd_rst_ctrl;
63 	void __iomem *crmu_usb2_ctrl;
64 	void __iomem *usb2h_strap_reg;
65 	struct ns2_phy_data *data;
66 	struct extcon_dev *edev;
67 	struct gpio_desc *vbus_gpiod;
68 	struct gpio_desc *id_gpiod;
69 	int id_irq;
70 	int vbus_irq;
71 	unsigned long debounce_jiffies;
72 	struct delayed_work wq_extcon;
73 };
74 
75 struct ns2_phy_data {
76 	struct ns2_phy_driver *driver;
77 	struct phy *phy;
78 	int new_state;
79 };
80 
81 static const unsigned int usb_extcon_cable[] = {
82 	EXTCON_USB,
83 	EXTCON_USB_HOST,
84 	EXTCON_NONE,
85 };
86 
87 static inline int pll_lock_stat(u32 usb_reg, int reg_mask,
88 				struct ns2_phy_driver *driver)
89 {
90 	int retry = PLL_LOCK_RETRY;
91 	u32 val;
92 
93 	do {
94 		udelay(1);
95 		val = readl(driver->icfgdrd_regs + usb_reg);
96 		if (val & reg_mask)
97 			return 0;
98 	} while (--retry > 0);
99 
100 	return -EBUSY;
101 }
102 
103 static int ns2_drd_phy_init(struct phy *phy)
104 {
105 	struct ns2_phy_data *data = phy_get_drvdata(phy);
106 	struct ns2_phy_driver *driver = data->driver;
107 	u32 val;
108 
109 	val = readl(driver->icfgdrd_regs + ICFG_FSM_CTRL);
110 
111 	if (data->new_state == EVT_HOST) {
112 		val &= ~DRD_DEVICE_MODE;
113 		val |= DRD_HOST_MODE;
114 	} else {
115 		val &= ~DRD_HOST_MODE;
116 		val |= DRD_DEVICE_MODE;
117 	}
118 	writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
119 
120 	return 0;
121 }
122 
123 static int ns2_drd_phy_poweroff(struct phy *phy)
124 {
125 	struct ns2_phy_data *data = phy_get_drvdata(phy);
126 	struct ns2_phy_driver *driver = data->driver;
127 	u32 val;
128 
129 	val = readl(driver->crmu_usb2_ctrl);
130 	val &= ~AFE_CORERDY_VDDC;
131 	writel(val, driver->crmu_usb2_ctrl);
132 
133 	val = readl(driver->crmu_usb2_ctrl);
134 	val &= ~DRD_DEV_MODE;
135 	writel(val, driver->crmu_usb2_ctrl);
136 
137 	/* Disable Host and Device Mode */
138 	val = readl(driver->icfgdrd_regs + ICFG_FSM_CTRL);
139 	val &= ~(DRD_HOST_MODE | DRD_DEVICE_MODE | ICFG_OFF_MODE);
140 	writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
141 
142 	return 0;
143 }
144 
145 static int ns2_drd_phy_poweron(struct phy *phy)
146 {
147 	struct ns2_phy_data *data = phy_get_drvdata(phy);
148 	struct ns2_phy_driver *driver = data->driver;
149 	u32 extcon_event = data->new_state;
150 	int ret;
151 	u32 val;
152 
153 	if (extcon_event == EVT_DEVICE) {
154 		writel(DRD_DEV_VAL, driver->icfgdrd_regs + ICFG_DRD_P0CTL);
155 
156 		val = readl(driver->idmdrd_rst_ctrl);
157 		val &= ~IDM_RST_BIT;
158 		writel(val, driver->idmdrd_rst_ctrl);
159 
160 		val = readl(driver->crmu_usb2_ctrl);
161 		val |= (AFE_CORERDY_VDDC | DRD_DEV_MODE);
162 		writel(val, driver->crmu_usb2_ctrl);
163 
164 		/* Bring PHY and PHY_PLL out of Reset */
165 		val = readl(driver->crmu_usb2_ctrl);
166 		val |= (PHY_PLL_RESETB | PHY_RESETB);
167 		writel(val, driver->crmu_usb2_ctrl);
168 
169 		ret = pll_lock_stat(ICFG_MISC_STAT, PHY_PLL_LOCK, driver);
170 		if (ret < 0) {
171 			dev_err(&phy->dev, "Phy PLL lock failed\n");
172 			return ret;
173 		}
174 	} else {
175 		writel(DRD_HOST_VAL, driver->icfgdrd_regs + ICFG_DRD_P0CTL);
176 
177 		val = readl(driver->crmu_usb2_ctrl);
178 		val |= AFE_CORERDY_VDDC;
179 		writel(val, driver->crmu_usb2_ctrl);
180 
181 		ret = pll_lock_stat(ICFG_MISC_STAT, PHY_PLL_LOCK, driver);
182 		if (ret < 0) {
183 			dev_err(&phy->dev, "Phy PLL lock failed\n");
184 			return ret;
185 		}
186 
187 		val = readl(driver->idmdrd_rst_ctrl);
188 		val &= ~IDM_RST_BIT;
189 		writel(val, driver->idmdrd_rst_ctrl);
190 
191 		/* port over current Polarity */
192 		val = readl(driver->usb2h_strap_reg);
193 		val |= OHCI_OVRCUR_POL;
194 		writel(val, driver->usb2h_strap_reg);
195 	}
196 
197 	return 0;
198 }
199 
200 static void connect_change(struct ns2_phy_driver *driver)
201 {
202 	u32 extcon_event;
203 	u32 val;
204 
205 	extcon_event = driver->data->new_state;
206 	val = readl(driver->icfgdrd_regs + ICFG_FSM_CTRL);
207 
208 	switch (extcon_event) {
209 	case EVT_DEVICE:
210 		val &= ~(DRD_HOST_MODE | DRD_DEVICE_MODE);
211 		writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
212 
213 		val = (val & ~DRD_HOST_MODE) | DRD_DEVICE_MODE;
214 		writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
215 
216 		val = readl(driver->icfgdrd_regs + ICFG_DRD_P0CTL);
217 		val |= ICFG_DEV_BIT;
218 		writel(val, driver->icfgdrd_regs + ICFG_DRD_P0CTL);
219 		break;
220 
221 	case EVT_HOST:
222 		val &= ~(DRD_HOST_MODE | DRD_DEVICE_MODE);
223 		writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
224 
225 		val = (val & ~DRD_DEVICE_MODE) | DRD_HOST_MODE;
226 		writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
227 
228 		val = readl(driver->usb2h_strap_reg);
229 		val |= OHCI_OVRCUR_POL;
230 		writel(val, driver->usb2h_strap_reg);
231 
232 		val = readl(driver->icfgdrd_regs + ICFG_DRD_P0CTL);
233 		val &= ~ICFG_DEV_BIT;
234 		writel(val, driver->icfgdrd_regs + ICFG_DRD_P0CTL);
235 		break;
236 
237 	default:
238 		pr_err("Invalid extcon event\n");
239 		break;
240 	}
241 }
242 
243 static void extcon_work(struct work_struct *work)
244 {
245 	struct ns2_phy_driver *driver;
246 	int vbus;
247 	int id;
248 
249 	driver  = container_of(to_delayed_work(work),
250 			       struct ns2_phy_driver, wq_extcon);
251 
252 	id = gpiod_get_value_cansleep(driver->id_gpiod);
253 	vbus = gpiod_get_value_cansleep(driver->vbus_gpiod);
254 
255 	if (!id && vbus) { /* Host connected */
256 		extcon_set_state_sync(driver->edev, EXTCON_USB_HOST, true);
257 		pr_debug("Host cable connected\n");
258 		driver->data->new_state = EVT_HOST;
259 		connect_change(driver);
260 	} else if (id && !vbus) { /* Disconnected */
261 		extcon_set_state_sync(driver->edev, EXTCON_USB_HOST, false);
262 		extcon_set_state_sync(driver->edev, EXTCON_USB, false);
263 		pr_debug("Cable disconnected\n");
264 	} else if (id && vbus) { /* Device connected */
265 		extcon_set_state_sync(driver->edev, EXTCON_USB, true);
266 		pr_debug("Device cable connected\n");
267 		driver->data->new_state = EVT_DEVICE;
268 		connect_change(driver);
269 	}
270 }
271 
272 static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
273 {
274 	struct ns2_phy_driver *driver = dev_id;
275 
276 	queue_delayed_work(system_power_efficient_wq, &driver->wq_extcon,
277 			   driver->debounce_jiffies);
278 
279 	return IRQ_HANDLED;
280 }
281 
282 static struct phy_ops ops = {
283 	.init		= ns2_drd_phy_init,
284 	.power_on	= ns2_drd_phy_poweron,
285 	.power_off	= ns2_drd_phy_poweroff,
286 	.owner		= THIS_MODULE,
287 };
288 
289 static const struct of_device_id ns2_drd_phy_dt_ids[] = {
290 	{ .compatible = "brcm,ns2-drd-phy", },
291 	{ }
292 };
293 MODULE_DEVICE_TABLE(of, ns2_drd_phy_dt_ids);
294 
295 static int ns2_drd_phy_probe(struct platform_device *pdev)
296 {
297 	struct phy_provider *phy_provider;
298 	struct device *dev = &pdev->dev;
299 	struct ns2_phy_driver *driver;
300 	struct ns2_phy_data *data;
301 	struct resource *res;
302 	int ret;
303 	u32 val;
304 
305 	driver = devm_kzalloc(dev, sizeof(struct ns2_phy_driver),
306 			      GFP_KERNEL);
307 	if (!driver)
308 		return -ENOMEM;
309 
310 	driver->data = devm_kzalloc(dev, sizeof(struct ns2_phy_data),
311 				  GFP_KERNEL);
312 	if (!driver->data)
313 		return -ENOMEM;
314 
315 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "icfg");
316 	driver->icfgdrd_regs = devm_ioremap_resource(dev, res);
317 	if (IS_ERR(driver->icfgdrd_regs))
318 		return PTR_ERR(driver->icfgdrd_regs);
319 
320 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rst-ctrl");
321 	driver->idmdrd_rst_ctrl = devm_ioremap_resource(dev, res);
322 	if (IS_ERR(driver->idmdrd_rst_ctrl))
323 		return PTR_ERR(driver->idmdrd_rst_ctrl);
324 
325 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "crmu-ctrl");
326 	driver->crmu_usb2_ctrl = devm_ioremap_resource(dev, res);
327 	if (IS_ERR(driver->crmu_usb2_ctrl))
328 		return PTR_ERR(driver->crmu_usb2_ctrl);
329 
330 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "usb2-strap");
331 	driver->usb2h_strap_reg = devm_ioremap_resource(dev, res);
332 	if (IS_ERR(driver->usb2h_strap_reg))
333 		return PTR_ERR(driver->usb2h_strap_reg);
334 
335 	 /* create extcon */
336 	driver->id_gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
337 	if (IS_ERR(driver->id_gpiod)) {
338 		dev_err(dev, "failed to get ID GPIO\n");
339 		return PTR_ERR(driver->id_gpiod);
340 	}
341 	driver->vbus_gpiod = devm_gpiod_get(&pdev->dev, "vbus", GPIOD_IN);
342 	if (IS_ERR(driver->vbus_gpiod)) {
343 		dev_err(dev, "failed to get VBUS GPIO\n");
344 		return PTR_ERR(driver->vbus_gpiod);
345 	}
346 
347 	driver->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable);
348 	if (IS_ERR(driver->edev)) {
349 		dev_err(dev, "failed to allocate extcon device\n");
350 		return -ENOMEM;
351 	}
352 
353 	ret = devm_extcon_dev_register(dev, driver->edev);
354 	if (ret < 0) {
355 		dev_err(dev, "failed to register extcon device\n");
356 		return ret;
357 	}
358 
359 	ret = gpiod_set_debounce(driver->id_gpiod, GPIO_DELAY * 1000);
360 	if (ret < 0)
361 		driver->debounce_jiffies = msecs_to_jiffies(GPIO_DELAY);
362 
363 	INIT_DELAYED_WORK(&driver->wq_extcon, extcon_work);
364 
365 	driver->id_irq = gpiod_to_irq(driver->id_gpiod);
366 	if (driver->id_irq < 0) {
367 		dev_err(dev, "failed to get ID IRQ\n");
368 		return driver->id_irq;
369 	}
370 
371 	driver->vbus_irq = gpiod_to_irq(driver->vbus_gpiod);
372 	if (driver->vbus_irq < 0) {
373 		dev_err(dev, "failed to get ID IRQ\n");
374 		return driver->vbus_irq;
375 	}
376 
377 	ret = devm_request_irq(dev, driver->id_irq, gpio_irq_handler,
378 			       IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
379 			       "usb_id", driver);
380 	if (ret < 0) {
381 		dev_err(dev, "failed to request handler for ID IRQ\n");
382 		return ret;
383 	}
384 
385 	ret = devm_request_irq(dev, driver->vbus_irq, gpio_irq_handler,
386 			       IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
387 			       "usb_vbus", driver);
388 	if (ret < 0) {
389 		dev_err(dev, "failed to request handler for VBUS IRQ\n");
390 		return ret;
391 	}
392 
393 	dev_set_drvdata(dev, driver);
394 
395 	/* Shutdown all ports. They can be powered up as required */
396 	val = readl(driver->crmu_usb2_ctrl);
397 	val &= ~(AFE_CORERDY_VDDC | PHY_RESETB);
398 	writel(val, driver->crmu_usb2_ctrl);
399 
400 	data = driver->data;
401 	data->phy = devm_phy_create(dev, dev->of_node, &ops);
402 	if (IS_ERR(data->phy)) {
403 		dev_err(dev, "Failed to create usb drd phy\n");
404 		return PTR_ERR(data->phy);
405 	}
406 
407 	data->driver = driver;
408 	phy_set_drvdata(data->phy, data);
409 
410 	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
411 	if (IS_ERR(phy_provider)) {
412 		dev_err(dev, "Failed to register as phy provider\n");
413 		return PTR_ERR(phy_provider);
414 	}
415 
416 	platform_set_drvdata(pdev, driver);
417 
418 	dev_info(dev, "Registered NS2 DRD Phy device\n");
419 	queue_delayed_work(system_power_efficient_wq, &driver->wq_extcon,
420 			   driver->debounce_jiffies);
421 
422 	return 0;
423 }
424 
425 static struct platform_driver ns2_drd_phy_driver = {
426 	.probe = ns2_drd_phy_probe,
427 	.driver = {
428 		.name = "bcm-ns2-usbphy",
429 		.of_match_table = of_match_ptr(ns2_drd_phy_dt_ids),
430 	},
431 };
432 module_platform_driver(ns2_drd_phy_driver);
433 
434 MODULE_ALIAS("platform:bcm-ns2-drd-phy");
435 MODULE_AUTHOR("Broadcom");
436 MODULE_DESCRIPTION("Broadcom NS2 USB2 PHY driver");
437 MODULE_LICENSE("GPL v2");
438