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