1 // SPDX-License-Identifier: GPL-2.0-only
2 // Copyright (C) 2017 Broadcom
3 
4 #include <linux/delay.h>
5 #include <linux/extcon-provider.h>
6 #include <linux/gpio.h>
7 #include <linux/gpio/consumer.h>
8 #include <linux/init.h>
9 #include <linux/interrupt.h>
10 #include <linux/io.h>
11 #include <linux/iopoll.h>
12 #include <linux/irq.h>
13 #include <linux/mfd/syscon.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/of_address.h>
17 #include <linux/phy/phy.h>
18 #include <linux/platform_device.h>
19 #include <linux/regmap.h>
20 #include <linux/slab.h>
21 #include <linux/workqueue.h>
22 
23 #define ICFG_DRD_AFE		0x0
24 #define ICFG_MISC_STAT		0x18
25 #define ICFG_DRD_P0CTL		0x1C
26 #define ICFG_STRAP_CTRL		0x20
27 #define ICFG_FSM_CTRL		0x24
28 
29 #define ICFG_DEV_BIT		BIT(2)
30 #define IDM_RST_BIT		BIT(0)
31 #define AFE_CORERDY_VDDC	BIT(18)
32 #define PHY_PLL_RESETB		BIT(15)
33 #define PHY_RESETB		BIT(14)
34 #define PHY_PLL_LOCK		BIT(0)
35 
36 #define DRD_DEV_MODE		BIT(20)
37 #define OHCI_OVRCUR_POL		BIT(11)
38 #define ICFG_OFF_MODE		BIT(6)
39 #define PLL_LOCK_RETRY		1000
40 
41 #define EVT_DEVICE		0
42 #define EVT_HOST		1
43 
44 #define DRD_HOST_MODE		(BIT(2) | BIT(3))
45 #define DRD_DEVICE_MODE		(BIT(4) | BIT(5))
46 #define DRD_HOST_VAL		0x803
47 #define DRD_DEV_VAL		0x807
48 #define GPIO_DELAY		20
49 
50 struct ns2_phy_data;
51 struct ns2_phy_driver {
52 	void __iomem *icfgdrd_regs;
53 	void __iomem *idmdrd_rst_ctrl;
54 	void __iomem *crmu_usb2_ctrl;
55 	void __iomem *usb2h_strap_reg;
56 	struct ns2_phy_data *data;
57 	struct extcon_dev *edev;
58 	struct gpio_desc *vbus_gpiod;
59 	struct gpio_desc *id_gpiod;
60 	int id_irq;
61 	int vbus_irq;
62 	unsigned long debounce_jiffies;
63 	struct delayed_work wq_extcon;
64 };
65 
66 struct ns2_phy_data {
67 	struct ns2_phy_driver *driver;
68 	struct phy *phy;
69 	int new_state;
70 };
71 
72 static const unsigned int usb_extcon_cable[] = {
73 	EXTCON_USB,
74 	EXTCON_USB_HOST,
75 	EXTCON_NONE,
76 };
77 
78 static inline int pll_lock_stat(u32 usb_reg, int reg_mask,
79 				struct ns2_phy_driver *driver)
80 {
81 	u32 val;
82 
83 	return readl_poll_timeout_atomic(driver->icfgdrd_regs + usb_reg,
84 					 val, (val & reg_mask), 1,
85 					 PLL_LOCK_RETRY);
86 }
87 
88 static int ns2_drd_phy_init(struct phy *phy)
89 {
90 	struct ns2_phy_data *data = phy_get_drvdata(phy);
91 	struct ns2_phy_driver *driver = data->driver;
92 	u32 val;
93 
94 	val = readl(driver->icfgdrd_regs + ICFG_FSM_CTRL);
95 
96 	if (data->new_state == EVT_HOST) {
97 		val &= ~DRD_DEVICE_MODE;
98 		val |= DRD_HOST_MODE;
99 	} else {
100 		val &= ~DRD_HOST_MODE;
101 		val |= DRD_DEVICE_MODE;
102 	}
103 	writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
104 
105 	return 0;
106 }
107 
108 static int ns2_drd_phy_poweroff(struct phy *phy)
109 {
110 	struct ns2_phy_data *data = phy_get_drvdata(phy);
111 	struct ns2_phy_driver *driver = data->driver;
112 	u32 val;
113 
114 	val = readl(driver->crmu_usb2_ctrl);
115 	val &= ~AFE_CORERDY_VDDC;
116 	writel(val, driver->crmu_usb2_ctrl);
117 
118 	val = readl(driver->crmu_usb2_ctrl);
119 	val &= ~DRD_DEV_MODE;
120 	writel(val, driver->crmu_usb2_ctrl);
121 
122 	/* Disable Host and Device Mode */
123 	val = readl(driver->icfgdrd_regs + ICFG_FSM_CTRL);
124 	val &= ~(DRD_HOST_MODE | DRD_DEVICE_MODE | ICFG_OFF_MODE);
125 	writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
126 
127 	return 0;
128 }
129 
130 static int ns2_drd_phy_poweron(struct phy *phy)
131 {
132 	struct ns2_phy_data *data = phy_get_drvdata(phy);
133 	struct ns2_phy_driver *driver = data->driver;
134 	u32 extcon_event = data->new_state;
135 	int ret;
136 	u32 val;
137 
138 	if (extcon_event == EVT_DEVICE) {
139 		writel(DRD_DEV_VAL, driver->icfgdrd_regs + ICFG_DRD_P0CTL);
140 
141 		val = readl(driver->idmdrd_rst_ctrl);
142 		val &= ~IDM_RST_BIT;
143 		writel(val, driver->idmdrd_rst_ctrl);
144 
145 		val = readl(driver->crmu_usb2_ctrl);
146 		val |= (AFE_CORERDY_VDDC | DRD_DEV_MODE);
147 		writel(val, driver->crmu_usb2_ctrl);
148 
149 		/* Bring PHY and PHY_PLL out of Reset */
150 		val = readl(driver->crmu_usb2_ctrl);
151 		val |= (PHY_PLL_RESETB | PHY_RESETB);
152 		writel(val, driver->crmu_usb2_ctrl);
153 
154 		ret = pll_lock_stat(ICFG_MISC_STAT, PHY_PLL_LOCK, driver);
155 		if (ret < 0) {
156 			dev_err(&phy->dev, "Phy PLL lock failed\n");
157 			return ret;
158 		}
159 	} else {
160 		writel(DRD_HOST_VAL, driver->icfgdrd_regs + ICFG_DRD_P0CTL);
161 
162 		val = readl(driver->crmu_usb2_ctrl);
163 		val |= AFE_CORERDY_VDDC;
164 		writel(val, driver->crmu_usb2_ctrl);
165 
166 		ret = pll_lock_stat(ICFG_MISC_STAT, PHY_PLL_LOCK, driver);
167 		if (ret < 0) {
168 			dev_err(&phy->dev, "Phy PLL lock failed\n");
169 			return ret;
170 		}
171 
172 		val = readl(driver->idmdrd_rst_ctrl);
173 		val &= ~IDM_RST_BIT;
174 		writel(val, driver->idmdrd_rst_ctrl);
175 
176 		/* port over current Polarity */
177 		val = readl(driver->usb2h_strap_reg);
178 		val |= OHCI_OVRCUR_POL;
179 		writel(val, driver->usb2h_strap_reg);
180 	}
181 
182 	return 0;
183 }
184 
185 static void connect_change(struct ns2_phy_driver *driver)
186 {
187 	u32 extcon_event;
188 	u32 val;
189 
190 	extcon_event = driver->data->new_state;
191 	val = readl(driver->icfgdrd_regs + ICFG_FSM_CTRL);
192 
193 	switch (extcon_event) {
194 	case EVT_DEVICE:
195 		val &= ~(DRD_HOST_MODE | DRD_DEVICE_MODE);
196 		writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
197 
198 		val = (val & ~DRD_HOST_MODE) | DRD_DEVICE_MODE;
199 		writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
200 
201 		val = readl(driver->icfgdrd_regs + ICFG_DRD_P0CTL);
202 		val |= ICFG_DEV_BIT;
203 		writel(val, driver->icfgdrd_regs + ICFG_DRD_P0CTL);
204 		break;
205 
206 	case EVT_HOST:
207 		val &= ~(DRD_HOST_MODE | DRD_DEVICE_MODE);
208 		writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
209 
210 		val = (val & ~DRD_DEVICE_MODE) | DRD_HOST_MODE;
211 		writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
212 
213 		val = readl(driver->usb2h_strap_reg);
214 		val |= OHCI_OVRCUR_POL;
215 		writel(val, driver->usb2h_strap_reg);
216 
217 		val = readl(driver->icfgdrd_regs + ICFG_DRD_P0CTL);
218 		val &= ~ICFG_DEV_BIT;
219 		writel(val, driver->icfgdrd_regs + ICFG_DRD_P0CTL);
220 		break;
221 
222 	default:
223 		pr_err("Invalid extcon event\n");
224 		break;
225 	}
226 }
227 
228 static void extcon_work(struct work_struct *work)
229 {
230 	struct ns2_phy_driver *driver;
231 	int vbus;
232 	int id;
233 
234 	driver  = container_of(to_delayed_work(work),
235 			       struct ns2_phy_driver, wq_extcon);
236 
237 	id = gpiod_get_value_cansleep(driver->id_gpiod);
238 	vbus = gpiod_get_value_cansleep(driver->vbus_gpiod);
239 
240 	if (!id && vbus) { /* Host connected */
241 		extcon_set_state_sync(driver->edev, EXTCON_USB_HOST, true);
242 		pr_debug("Host cable connected\n");
243 		driver->data->new_state = EVT_HOST;
244 		connect_change(driver);
245 	} else if (id && !vbus) { /* Disconnected */
246 		extcon_set_state_sync(driver->edev, EXTCON_USB_HOST, false);
247 		extcon_set_state_sync(driver->edev, EXTCON_USB, false);
248 		pr_debug("Cable disconnected\n");
249 	} else if (id && vbus) { /* Device connected */
250 		extcon_set_state_sync(driver->edev, EXTCON_USB, true);
251 		pr_debug("Device cable connected\n");
252 		driver->data->new_state = EVT_DEVICE;
253 		connect_change(driver);
254 	}
255 }
256 
257 static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
258 {
259 	struct ns2_phy_driver *driver = dev_id;
260 
261 	queue_delayed_work(system_power_efficient_wq, &driver->wq_extcon,
262 			   driver->debounce_jiffies);
263 
264 	return IRQ_HANDLED;
265 }
266 
267 static const struct phy_ops ops = {
268 	.init		= ns2_drd_phy_init,
269 	.power_on	= ns2_drd_phy_poweron,
270 	.power_off	= ns2_drd_phy_poweroff,
271 	.owner		= THIS_MODULE,
272 };
273 
274 static const struct of_device_id ns2_drd_phy_dt_ids[] = {
275 	{ .compatible = "brcm,ns2-drd-phy", },
276 	{ }
277 };
278 MODULE_DEVICE_TABLE(of, ns2_drd_phy_dt_ids);
279 
280 static int ns2_drd_phy_probe(struct platform_device *pdev)
281 {
282 	struct phy_provider *phy_provider;
283 	struct device *dev = &pdev->dev;
284 	struct ns2_phy_driver *driver;
285 	struct ns2_phy_data *data;
286 	int ret;
287 	u32 val;
288 
289 	driver = devm_kzalloc(dev, sizeof(struct ns2_phy_driver),
290 			      GFP_KERNEL);
291 	if (!driver)
292 		return -ENOMEM;
293 
294 	driver->data = devm_kzalloc(dev, sizeof(struct ns2_phy_data),
295 				  GFP_KERNEL);
296 	if (!driver->data)
297 		return -ENOMEM;
298 
299 	driver->icfgdrd_regs = devm_platform_ioremap_resource_byname(pdev, "icfg");
300 	if (IS_ERR(driver->icfgdrd_regs))
301 		return PTR_ERR(driver->icfgdrd_regs);
302 
303 	driver->idmdrd_rst_ctrl = devm_platform_ioremap_resource_byname(pdev, "rst-ctrl");
304 	if (IS_ERR(driver->idmdrd_rst_ctrl))
305 		return PTR_ERR(driver->idmdrd_rst_ctrl);
306 
307 	driver->crmu_usb2_ctrl = devm_platform_ioremap_resource_byname(pdev, "crmu-ctrl");
308 	if (IS_ERR(driver->crmu_usb2_ctrl))
309 		return PTR_ERR(driver->crmu_usb2_ctrl);
310 
311 	driver->usb2h_strap_reg = devm_platform_ioremap_resource_byname(pdev, "usb2-strap");
312 	if (IS_ERR(driver->usb2h_strap_reg))
313 		return PTR_ERR(driver->usb2h_strap_reg);
314 
315 	 /* create extcon */
316 	driver->id_gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
317 	if (IS_ERR(driver->id_gpiod)) {
318 		dev_err(dev, "failed to get ID GPIO\n");
319 		return PTR_ERR(driver->id_gpiod);
320 	}
321 	driver->vbus_gpiod = devm_gpiod_get(&pdev->dev, "vbus", GPIOD_IN);
322 	if (IS_ERR(driver->vbus_gpiod)) {
323 		dev_err(dev, "failed to get VBUS GPIO\n");
324 		return PTR_ERR(driver->vbus_gpiod);
325 	}
326 
327 	driver->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable);
328 	if (IS_ERR(driver->edev)) {
329 		dev_err(dev, "failed to allocate extcon device\n");
330 		return -ENOMEM;
331 	}
332 
333 	ret = devm_extcon_dev_register(dev, driver->edev);
334 	if (ret < 0) {
335 		dev_err(dev, "failed to register extcon device\n");
336 		return ret;
337 	}
338 
339 	ret = gpiod_set_debounce(driver->id_gpiod, GPIO_DELAY * 1000);
340 	if (ret < 0)
341 		driver->debounce_jiffies = msecs_to_jiffies(GPIO_DELAY);
342 
343 	INIT_DELAYED_WORK(&driver->wq_extcon, extcon_work);
344 
345 	driver->id_irq = gpiod_to_irq(driver->id_gpiod);
346 	if (driver->id_irq < 0) {
347 		dev_err(dev, "failed to get ID IRQ\n");
348 		return driver->id_irq;
349 	}
350 
351 	driver->vbus_irq = gpiod_to_irq(driver->vbus_gpiod);
352 	if (driver->vbus_irq < 0) {
353 		dev_err(dev, "failed to get ID IRQ\n");
354 		return driver->vbus_irq;
355 	}
356 
357 	ret = devm_request_irq(dev, driver->id_irq, gpio_irq_handler,
358 			       IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
359 			       "usb_id", driver);
360 	if (ret < 0) {
361 		dev_err(dev, "failed to request handler for ID IRQ\n");
362 		return ret;
363 	}
364 
365 	ret = devm_request_irq(dev, driver->vbus_irq, gpio_irq_handler,
366 			       IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
367 			       "usb_vbus", driver);
368 	if (ret < 0) {
369 		dev_err(dev, "failed to request handler for VBUS IRQ\n");
370 		return ret;
371 	}
372 
373 	dev_set_drvdata(dev, driver);
374 
375 	/* Shutdown all ports. They can be powered up as required */
376 	val = readl(driver->crmu_usb2_ctrl);
377 	val &= ~(AFE_CORERDY_VDDC | PHY_RESETB);
378 	writel(val, driver->crmu_usb2_ctrl);
379 
380 	data = driver->data;
381 	data->phy = devm_phy_create(dev, dev->of_node, &ops);
382 	if (IS_ERR(data->phy)) {
383 		dev_err(dev, "Failed to create usb drd phy\n");
384 		return PTR_ERR(data->phy);
385 	}
386 
387 	data->driver = driver;
388 	phy_set_drvdata(data->phy, data);
389 
390 	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
391 	if (IS_ERR(phy_provider)) {
392 		dev_err(dev, "Failed to register as phy provider\n");
393 		return PTR_ERR(phy_provider);
394 	}
395 
396 	platform_set_drvdata(pdev, driver);
397 
398 	dev_info(dev, "Registered NS2 DRD Phy device\n");
399 	queue_delayed_work(system_power_efficient_wq, &driver->wq_extcon,
400 			   driver->debounce_jiffies);
401 
402 	return 0;
403 }
404 
405 static struct platform_driver ns2_drd_phy_driver = {
406 	.probe = ns2_drd_phy_probe,
407 	.driver = {
408 		.name = "bcm-ns2-usbphy",
409 		.of_match_table = of_match_ptr(ns2_drd_phy_dt_ids),
410 	},
411 };
412 module_platform_driver(ns2_drd_phy_driver);
413 
414 MODULE_ALIAS("platform:bcm-ns2-drd-phy");
415 MODULE_AUTHOR("Broadcom");
416 MODULE_DESCRIPTION("Broadcom NS2 USB2 PHY driver");
417 MODULE_LICENSE("GPL v2");
418