1 /*
2  * Palmas USB transceiver driver
3  *
4  * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * Author: Graeme Gregory <gg@slimlogic.co.uk>
11  * Author: Kishon Vijay Abraham I <kishon@ti.com>
12  *
13  * Based on twl6030_usb.c
14  *
15  * Author: Hema HK <hemahk@ti.com>
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  */
22 
23 #include <linux/module.h>
24 #include <linux/interrupt.h>
25 #include <linux/platform_device.h>
26 #include <linux/slab.h>
27 #include <linux/err.h>
28 #include <linux/mfd/palmas.h>
29 #include <linux/of.h>
30 #include <linux/of_platform.h>
31 #include <linux/of_gpio.h>
32 #include <linux/gpio/consumer.h>
33 #include <linux/workqueue.h>
34 
35 #define USB_GPIO_DEBOUNCE_MS	20	/* ms */
36 
37 static const unsigned int palmas_extcon_cable[] = {
38 	EXTCON_USB,
39 	EXTCON_USB_HOST,
40 	EXTCON_NONE,
41 };
42 
43 static void palmas_usb_wakeup(struct palmas *palmas, int enable)
44 {
45 	if (enable)
46 		palmas_write(palmas, PALMAS_USB_OTG_BASE, PALMAS_USB_WAKEUP,
47 			PALMAS_USB_WAKEUP_ID_WK_UP_COMP);
48 	else
49 		palmas_write(palmas, PALMAS_USB_OTG_BASE, PALMAS_USB_WAKEUP, 0);
50 }
51 
52 static irqreturn_t palmas_vbus_irq_handler(int irq, void *_palmas_usb)
53 {
54 	struct palmas_usb *palmas_usb = _palmas_usb;
55 	struct extcon_dev *edev = palmas_usb->edev;
56 	unsigned int vbus_line_state;
57 
58 	palmas_read(palmas_usb->palmas, PALMAS_INTERRUPT_BASE,
59 		PALMAS_INT3_LINE_STATE, &vbus_line_state);
60 
61 	if (vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS) {
62 		if (palmas_usb->linkstat != PALMAS_USB_STATE_VBUS) {
63 			palmas_usb->linkstat = PALMAS_USB_STATE_VBUS;
64 			extcon_set_cable_state_(edev, EXTCON_USB, true);
65 			dev_info(palmas_usb->dev, "USB cable is attached\n");
66 		} else {
67 			dev_dbg(palmas_usb->dev,
68 				"Spurious connect event detected\n");
69 		}
70 	} else if (!(vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS)) {
71 		if (palmas_usb->linkstat == PALMAS_USB_STATE_VBUS) {
72 			palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
73 			extcon_set_cable_state_(edev, EXTCON_USB, false);
74 			dev_info(palmas_usb->dev, "USB cable is detached\n");
75 		} else {
76 			dev_dbg(palmas_usb->dev,
77 				"Spurious disconnect event detected\n");
78 		}
79 	}
80 
81 	return IRQ_HANDLED;
82 }
83 
84 static irqreturn_t palmas_id_irq_handler(int irq, void *_palmas_usb)
85 {
86 	unsigned int set, id_src;
87 	struct palmas_usb *palmas_usb = _palmas_usb;
88 	struct extcon_dev *edev = palmas_usb->edev;
89 
90 	palmas_read(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
91 		PALMAS_USB_ID_INT_LATCH_SET, &set);
92 	palmas_read(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
93 		PALMAS_USB_ID_INT_SRC, &id_src);
94 
95 	if ((set & PALMAS_USB_ID_INT_SRC_ID_GND) &&
96 				(id_src & PALMAS_USB_ID_INT_SRC_ID_GND)) {
97 		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
98 			PALMAS_USB_ID_INT_LATCH_CLR,
99 			PALMAS_USB_ID_INT_EN_HI_CLR_ID_GND);
100 		palmas_usb->linkstat = PALMAS_USB_STATE_ID;
101 		extcon_set_cable_state_(edev, EXTCON_USB_HOST, true);
102 		dev_info(palmas_usb->dev, "USB-HOST cable is attached\n");
103 	} else if ((set & PALMAS_USB_ID_INT_SRC_ID_FLOAT) &&
104 				(id_src & PALMAS_USB_ID_INT_SRC_ID_FLOAT)) {
105 		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
106 			PALMAS_USB_ID_INT_LATCH_CLR,
107 			PALMAS_USB_ID_INT_EN_HI_CLR_ID_FLOAT);
108 		palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
109 		extcon_set_cable_state_(edev, EXTCON_USB_HOST, false);
110 		dev_info(palmas_usb->dev, "USB-HOST cable is detached\n");
111 	} else if ((palmas_usb->linkstat == PALMAS_USB_STATE_ID) &&
112 				(!(set & PALMAS_USB_ID_INT_SRC_ID_GND))) {
113 		palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
114 		extcon_set_cable_state_(edev, EXTCON_USB_HOST, false);
115 		dev_info(palmas_usb->dev, "USB-HOST cable is detached\n");
116 	} else if ((palmas_usb->linkstat == PALMAS_USB_STATE_DISCONNECT) &&
117 				(id_src & PALMAS_USB_ID_INT_SRC_ID_GND)) {
118 		palmas_usb->linkstat = PALMAS_USB_STATE_ID;
119 		extcon_set_cable_state_(edev, EXTCON_USB_HOST, true);
120 		dev_info(palmas_usb->dev, " USB-HOST cable is attached\n");
121 	}
122 
123 	return IRQ_HANDLED;
124 }
125 
126 static void palmas_gpio_id_detect(struct work_struct *work)
127 {
128 	int id;
129 	struct palmas_usb *palmas_usb = container_of(to_delayed_work(work),
130 						     struct palmas_usb,
131 						     wq_detectid);
132 	struct extcon_dev *edev = palmas_usb->edev;
133 
134 	if (!palmas_usb->id_gpiod)
135 		return;
136 
137 	id = gpiod_get_value_cansleep(palmas_usb->id_gpiod);
138 
139 	if (id) {
140 		extcon_set_cable_state_(edev, EXTCON_USB_HOST, false);
141 		dev_info(palmas_usb->dev, "USB-HOST cable is detached\n");
142 	} else {
143 		extcon_set_cable_state_(edev, EXTCON_USB_HOST, true);
144 		dev_info(palmas_usb->dev, "USB-HOST cable is attached\n");
145 	}
146 }
147 
148 static irqreturn_t palmas_gpio_id_irq_handler(int irq, void *_palmas_usb)
149 {
150 	struct palmas_usb *palmas_usb = _palmas_usb;
151 
152 	queue_delayed_work(system_power_efficient_wq, &palmas_usb->wq_detectid,
153 			   palmas_usb->sw_debounce_jiffies);
154 
155 	return IRQ_HANDLED;
156 }
157 
158 static void palmas_enable_irq(struct palmas_usb *palmas_usb)
159 {
160 	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
161 		PALMAS_USB_VBUS_CTRL_SET,
162 		PALMAS_USB_VBUS_CTRL_SET_VBUS_ACT_COMP);
163 
164 	if (palmas_usb->enable_id_detection) {
165 		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
166 			     PALMAS_USB_ID_CTRL_SET,
167 			     PALMAS_USB_ID_CTRL_SET_ID_ACT_COMP);
168 
169 		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
170 			     PALMAS_USB_ID_INT_EN_HI_SET,
171 			     PALMAS_USB_ID_INT_EN_HI_SET_ID_GND |
172 			     PALMAS_USB_ID_INT_EN_HI_SET_ID_FLOAT);
173 	}
174 
175 	if (palmas_usb->enable_vbus_detection)
176 		palmas_vbus_irq_handler(palmas_usb->vbus_irq, palmas_usb);
177 
178 	/* cold plug for host mode needs this delay */
179 	if (palmas_usb->enable_id_detection) {
180 		msleep(30);
181 		palmas_id_irq_handler(palmas_usb->id_irq, palmas_usb);
182 	}
183 }
184 
185 static int palmas_usb_probe(struct platform_device *pdev)
186 {
187 	struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
188 	struct palmas_usb_platform_data	*pdata = dev_get_platdata(&pdev->dev);
189 	struct device_node *node = pdev->dev.of_node;
190 	struct palmas_usb *palmas_usb;
191 	int status;
192 
193 	palmas_usb = devm_kzalloc(&pdev->dev, sizeof(*palmas_usb), GFP_KERNEL);
194 	if (!palmas_usb)
195 		return -ENOMEM;
196 
197 	if (node && !pdata) {
198 		palmas_usb->wakeup = of_property_read_bool(node, "ti,wakeup");
199 		palmas_usb->enable_id_detection = of_property_read_bool(node,
200 						"ti,enable-id-detection");
201 		palmas_usb->enable_vbus_detection = of_property_read_bool(node,
202 						"ti,enable-vbus-detection");
203 	} else {
204 		palmas_usb->wakeup = true;
205 		palmas_usb->enable_id_detection = true;
206 		palmas_usb->enable_vbus_detection = true;
207 
208 		if (pdata)
209 			palmas_usb->wakeup = pdata->wakeup;
210 	}
211 
212 	palmas_usb->id_gpiod = devm_gpiod_get_optional(&pdev->dev, "id",
213 							GPIOD_IN);
214 	if (IS_ERR(palmas_usb->id_gpiod)) {
215 		dev_err(&pdev->dev, "failed to get id gpio\n");
216 		return PTR_ERR(palmas_usb->id_gpiod);
217 	}
218 
219 	if (palmas_usb->enable_id_detection && palmas_usb->id_gpiod) {
220 		palmas_usb->enable_id_detection = false;
221 		palmas_usb->enable_gpio_id_detection = true;
222 	}
223 
224 	if (palmas_usb->enable_gpio_id_detection) {
225 		u32 debounce;
226 
227 		if (of_property_read_u32(node, "debounce-delay-ms", &debounce))
228 			debounce = USB_GPIO_DEBOUNCE_MS;
229 
230 		status = gpiod_set_debounce(palmas_usb->id_gpiod,
231 					    debounce * 1000);
232 		if (status < 0)
233 			palmas_usb->sw_debounce_jiffies = msecs_to_jiffies(debounce);
234 	}
235 
236 	INIT_DELAYED_WORK(&palmas_usb->wq_detectid, palmas_gpio_id_detect);
237 
238 	palmas->usb = palmas_usb;
239 	palmas_usb->palmas = palmas;
240 
241 	palmas_usb->dev	 = &pdev->dev;
242 
243 	palmas_usb_wakeup(palmas, palmas_usb->wakeup);
244 
245 	platform_set_drvdata(pdev, palmas_usb);
246 
247 	palmas_usb->edev = devm_extcon_dev_allocate(&pdev->dev,
248 						    palmas_extcon_cable);
249 	if (IS_ERR(palmas_usb->edev)) {
250 		dev_err(&pdev->dev, "failed to allocate extcon device\n");
251 		return -ENOMEM;
252 	}
253 
254 	status = devm_extcon_dev_register(&pdev->dev, palmas_usb->edev);
255 	if (status) {
256 		dev_err(&pdev->dev, "failed to register extcon device\n");
257 		return status;
258 	}
259 
260 	if (palmas_usb->enable_id_detection) {
261 		palmas_usb->id_otg_irq = regmap_irq_get_virq(palmas->irq_data,
262 							     PALMAS_ID_OTG_IRQ);
263 		palmas_usb->id_irq = regmap_irq_get_virq(palmas->irq_data,
264 							 PALMAS_ID_IRQ);
265 		status = devm_request_threaded_irq(palmas_usb->dev,
266 				palmas_usb->id_irq,
267 				NULL, palmas_id_irq_handler,
268 				IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING |
269 				IRQF_ONESHOT | IRQF_EARLY_RESUME,
270 				"palmas_usb_id", palmas_usb);
271 		if (status < 0) {
272 			dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
273 					palmas_usb->id_irq, status);
274 			return status;
275 		}
276 	} else if (palmas_usb->enable_gpio_id_detection) {
277 		palmas_usb->gpio_id_irq = gpiod_to_irq(palmas_usb->id_gpiod);
278 		if (palmas_usb->gpio_id_irq < 0) {
279 			dev_err(&pdev->dev, "failed to get id irq\n");
280 			return palmas_usb->gpio_id_irq;
281 		}
282 		status = devm_request_threaded_irq(&pdev->dev,
283 						   palmas_usb->gpio_id_irq,
284 						   NULL,
285 						   palmas_gpio_id_irq_handler,
286 						   IRQF_TRIGGER_RISING |
287 						   IRQF_TRIGGER_FALLING |
288 						   IRQF_ONESHOT,
289 						   "palmas_usb_id",
290 						   palmas_usb);
291 		if (status < 0) {
292 			dev_err(&pdev->dev,
293 				"failed to request handler for id irq\n");
294 			return status;
295 		}
296 	}
297 
298 	if (palmas_usb->enable_vbus_detection) {
299 		palmas_usb->vbus_otg_irq = regmap_irq_get_virq(palmas->irq_data,
300 						       PALMAS_VBUS_OTG_IRQ);
301 		palmas_usb->vbus_irq = regmap_irq_get_virq(palmas->irq_data,
302 							   PALMAS_VBUS_IRQ);
303 		status = devm_request_threaded_irq(palmas_usb->dev,
304 				palmas_usb->vbus_irq, NULL,
305 				palmas_vbus_irq_handler,
306 				IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING |
307 				IRQF_ONESHOT | IRQF_EARLY_RESUME,
308 				"palmas_usb_vbus", palmas_usb);
309 		if (status < 0) {
310 			dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
311 					palmas_usb->vbus_irq, status);
312 			return status;
313 		}
314 	}
315 
316 	palmas_enable_irq(palmas_usb);
317 	/* perform initial detection */
318 	palmas_gpio_id_detect(&palmas_usb->wq_detectid.work);
319 	device_set_wakeup_capable(&pdev->dev, true);
320 	return 0;
321 }
322 
323 static int palmas_usb_remove(struct platform_device *pdev)
324 {
325 	struct palmas_usb *palmas_usb = platform_get_drvdata(pdev);
326 
327 	cancel_delayed_work_sync(&palmas_usb->wq_detectid);
328 
329 	return 0;
330 }
331 
332 #ifdef CONFIG_PM_SLEEP
333 static int palmas_usb_suspend(struct device *dev)
334 {
335 	struct palmas_usb *palmas_usb = dev_get_drvdata(dev);
336 
337 	if (device_may_wakeup(dev)) {
338 		if (palmas_usb->enable_vbus_detection)
339 			enable_irq_wake(palmas_usb->vbus_irq);
340 		if (palmas_usb->enable_id_detection)
341 			enable_irq_wake(palmas_usb->id_irq);
342 		if (palmas_usb->enable_gpio_id_detection)
343 			enable_irq_wake(palmas_usb->gpio_id_irq);
344 	}
345 	return 0;
346 }
347 
348 static int palmas_usb_resume(struct device *dev)
349 {
350 	struct palmas_usb *palmas_usb = dev_get_drvdata(dev);
351 
352 	if (device_may_wakeup(dev)) {
353 		if (palmas_usb->enable_vbus_detection)
354 			disable_irq_wake(palmas_usb->vbus_irq);
355 		if (palmas_usb->enable_id_detection)
356 			disable_irq_wake(palmas_usb->id_irq);
357 		if (palmas_usb->enable_gpio_id_detection)
358 			disable_irq_wake(palmas_usb->gpio_id_irq);
359 	}
360 	return 0;
361 };
362 #endif
363 
364 static SIMPLE_DEV_PM_OPS(palmas_pm_ops, palmas_usb_suspend, palmas_usb_resume);
365 
366 static const struct of_device_id of_palmas_match_tbl[] = {
367 	{ .compatible = "ti,palmas-usb", },
368 	{ .compatible = "ti,palmas-usb-vid", },
369 	{ .compatible = "ti,twl6035-usb", },
370 	{ .compatible = "ti,twl6035-usb-vid", },
371 	{ /* end */ }
372 };
373 
374 static struct platform_driver palmas_usb_driver = {
375 	.probe = palmas_usb_probe,
376 	.remove = palmas_usb_remove,
377 	.driver = {
378 		.name = "palmas-usb",
379 		.of_match_table = of_palmas_match_tbl,
380 		.pm = &palmas_pm_ops,
381 	},
382 };
383 
384 module_platform_driver(palmas_usb_driver);
385 
386 MODULE_ALIAS("platform:palmas-usb");
387 MODULE_AUTHOR("Graeme Gregory <gg@slimlogic.co.uk>");
388 MODULE_DESCRIPTION("Palmas USB transceiver driver");
389 MODULE_LICENSE("GPL");
390 MODULE_DEVICE_TABLE(of, of_palmas_match_tbl);
391