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 
32 static const char *palmas_extcon_cable[] = {
33 	[0] = "USB",
34 	[1] = "USB-HOST",
35 	NULL,
36 };
37 
38 static const int mutually_exclusive[] = {0x3, 0x0};
39 
40 static void palmas_usb_wakeup(struct palmas *palmas, int enable)
41 {
42 	if (enable)
43 		palmas_write(palmas, PALMAS_USB_OTG_BASE, PALMAS_USB_WAKEUP,
44 			PALMAS_USB_WAKEUP_ID_WK_UP_COMP);
45 	else
46 		palmas_write(palmas, PALMAS_USB_OTG_BASE, PALMAS_USB_WAKEUP, 0);
47 }
48 
49 static irqreturn_t palmas_vbus_irq_handler(int irq, void *_palmas_usb)
50 {
51 	struct palmas_usb *palmas_usb = _palmas_usb;
52 	unsigned int vbus_line_state;
53 
54 	palmas_read(palmas_usb->palmas, PALMAS_INTERRUPT_BASE,
55 		PALMAS_INT3_LINE_STATE, &vbus_line_state);
56 
57 	if (vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS) {
58 		if (palmas_usb->linkstat != PALMAS_USB_STATE_VBUS) {
59 			palmas_usb->linkstat = PALMAS_USB_STATE_VBUS;
60 			extcon_set_cable_state(palmas_usb->edev, "USB", true);
61 			dev_info(palmas_usb->dev, "USB cable is attached\n");
62 		} else {
63 			dev_dbg(palmas_usb->dev,
64 				"Spurious connect event detected\n");
65 		}
66 	} else if (!(vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS)) {
67 		if (palmas_usb->linkstat == PALMAS_USB_STATE_VBUS) {
68 			palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
69 			extcon_set_cable_state(palmas_usb->edev, "USB", false);
70 			dev_info(palmas_usb->dev, "USB cable is detached\n");
71 		} else {
72 			dev_dbg(palmas_usb->dev,
73 				"Spurious disconnect event detected\n");
74 		}
75 	}
76 
77 	return IRQ_HANDLED;
78 }
79 
80 static irqreturn_t palmas_id_irq_handler(int irq, void *_palmas_usb)
81 {
82 	unsigned int set, id_src;
83 	struct palmas_usb *palmas_usb = _palmas_usb;
84 
85 	palmas_read(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
86 		PALMAS_USB_ID_INT_LATCH_SET, &set);
87 	palmas_read(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
88 		PALMAS_USB_ID_INT_SRC, &id_src);
89 
90 	if ((set & PALMAS_USB_ID_INT_SRC_ID_GND) &&
91 				(id_src & PALMAS_USB_ID_INT_SRC_ID_GND)) {
92 		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
93 			PALMAS_USB_ID_INT_LATCH_CLR,
94 			PALMAS_USB_ID_INT_EN_HI_CLR_ID_GND);
95 		palmas_usb->linkstat = PALMAS_USB_STATE_ID;
96 		extcon_set_cable_state(palmas_usb->edev, "USB-HOST", true);
97 		dev_info(palmas_usb->dev, "USB-HOST cable is attached\n");
98 	} else if ((set & PALMAS_USB_ID_INT_SRC_ID_FLOAT) &&
99 				(id_src & PALMAS_USB_ID_INT_SRC_ID_FLOAT)) {
100 		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
101 			PALMAS_USB_ID_INT_LATCH_CLR,
102 			PALMAS_USB_ID_INT_EN_HI_CLR_ID_FLOAT);
103 		palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
104 		extcon_set_cable_state(palmas_usb->edev, "USB-HOST", false);
105 		dev_info(palmas_usb->dev, "USB-HOST cable is detached\n");
106 	} else if ((palmas_usb->linkstat == PALMAS_USB_STATE_ID) &&
107 				(!(set & PALMAS_USB_ID_INT_SRC_ID_GND))) {
108 		palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
109 		extcon_set_cable_state(palmas_usb->edev, "USB-HOST", false);
110 		dev_info(palmas_usb->dev, "USB-HOST cable is detached\n");
111 	} else if ((palmas_usb->linkstat == PALMAS_USB_STATE_DISCONNECT) &&
112 				(id_src & PALMAS_USB_ID_INT_SRC_ID_GND)) {
113 		palmas_usb->linkstat = PALMAS_USB_STATE_ID;
114 		extcon_set_cable_state(palmas_usb->edev, "USB-HOST", true);
115 		dev_info(palmas_usb->dev, " USB-HOST cable is attached\n");
116 	}
117 
118 	return IRQ_HANDLED;
119 }
120 
121 static void palmas_enable_irq(struct palmas_usb *palmas_usb)
122 {
123 	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
124 		PALMAS_USB_VBUS_CTRL_SET,
125 		PALMAS_USB_VBUS_CTRL_SET_VBUS_ACT_COMP);
126 
127 	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
128 		PALMAS_USB_ID_CTRL_SET, PALMAS_USB_ID_CTRL_SET_ID_ACT_COMP);
129 
130 	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
131 		PALMAS_USB_ID_INT_EN_HI_SET,
132 		PALMAS_USB_ID_INT_EN_HI_SET_ID_GND |
133 		PALMAS_USB_ID_INT_EN_HI_SET_ID_FLOAT);
134 
135 	if (palmas_usb->enable_vbus_detection)
136 		palmas_vbus_irq_handler(palmas_usb->vbus_irq, palmas_usb);
137 
138 	/* cold plug for host mode needs this delay */
139 	if (palmas_usb->enable_id_detection) {
140 		msleep(30);
141 		palmas_id_irq_handler(palmas_usb->id_irq, palmas_usb);
142 	}
143 }
144 
145 static int palmas_usb_probe(struct platform_device *pdev)
146 {
147 	struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
148 	struct palmas_usb_platform_data	*pdata = dev_get_platdata(&pdev->dev);
149 	struct device_node *node = pdev->dev.of_node;
150 	struct palmas_usb *palmas_usb;
151 	int status;
152 
153 	palmas_usb = devm_kzalloc(&pdev->dev, sizeof(*palmas_usb), GFP_KERNEL);
154 	if (!palmas_usb)
155 		return -ENOMEM;
156 
157 	if (node && !pdata) {
158 		palmas_usb->wakeup = of_property_read_bool(node, "ti,wakeup");
159 		palmas_usb->enable_id_detection = of_property_read_bool(node,
160 						"ti,enable-id-detection");
161 		palmas_usb->enable_vbus_detection = of_property_read_bool(node,
162 						"ti,enable-vbus-detection");
163 	} else {
164 		palmas_usb->wakeup = true;
165 		palmas_usb->enable_id_detection = true;
166 		palmas_usb->enable_vbus_detection = true;
167 
168 		if (pdata)
169 			palmas_usb->wakeup = pdata->wakeup;
170 	}
171 
172 	palmas->usb = palmas_usb;
173 	palmas_usb->palmas = palmas;
174 
175 	palmas_usb->dev	 = &pdev->dev;
176 
177 	palmas_usb->id_otg_irq = regmap_irq_get_virq(palmas->irq_data,
178 						PALMAS_ID_OTG_IRQ);
179 	palmas_usb->id_irq = regmap_irq_get_virq(palmas->irq_data,
180 						PALMAS_ID_IRQ);
181 	palmas_usb->vbus_otg_irq = regmap_irq_get_virq(palmas->irq_data,
182 						PALMAS_VBUS_OTG_IRQ);
183 	palmas_usb->vbus_irq = regmap_irq_get_virq(palmas->irq_data,
184 						PALMAS_VBUS_IRQ);
185 
186 	palmas_usb_wakeup(palmas, palmas_usb->wakeup);
187 
188 	platform_set_drvdata(pdev, palmas_usb);
189 
190 	palmas_usb->edev = devm_extcon_dev_allocate(&pdev->dev,
191 						    palmas_extcon_cable);
192 	if (IS_ERR(palmas_usb->edev)) {
193 		dev_err(&pdev->dev, "failed to allocate extcon device\n");
194 		return -ENOMEM;
195 	}
196 	palmas_usb->edev->name = kstrdup(node->name, GFP_KERNEL);
197 	palmas_usb->edev->mutually_exclusive = mutually_exclusive;
198 
199 	status = devm_extcon_dev_register(&pdev->dev, palmas_usb->edev);
200 	if (status) {
201 		dev_err(&pdev->dev, "failed to register extcon device\n");
202 		kfree(palmas_usb->edev->name);
203 		return status;
204 	}
205 
206 	if (palmas_usb->enable_id_detection) {
207 		status = devm_request_threaded_irq(palmas_usb->dev,
208 				palmas_usb->id_irq,
209 				NULL, palmas_id_irq_handler,
210 				IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING |
211 				IRQF_ONESHOT | IRQF_EARLY_RESUME,
212 				"palmas_usb_id", palmas_usb);
213 		if (status < 0) {
214 			dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
215 					palmas_usb->id_irq, status);
216 			kfree(palmas_usb->edev->name);
217 			return status;
218 		}
219 	}
220 
221 	if (palmas_usb->enable_vbus_detection) {
222 		status = devm_request_threaded_irq(palmas_usb->dev,
223 				palmas_usb->vbus_irq, NULL,
224 				palmas_vbus_irq_handler,
225 				IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING |
226 				IRQF_ONESHOT | IRQF_EARLY_RESUME,
227 				"palmas_usb_vbus", palmas_usb);
228 		if (status < 0) {
229 			dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
230 					palmas_usb->vbus_irq, status);
231 			kfree(palmas_usb->edev->name);
232 			return status;
233 		}
234 	}
235 
236 	palmas_enable_irq(palmas_usb);
237 	device_set_wakeup_capable(&pdev->dev, true);
238 	return 0;
239 }
240 
241 static int palmas_usb_remove(struct platform_device *pdev)
242 {
243 	struct palmas_usb *palmas_usb = platform_get_drvdata(pdev);
244 
245 	kfree(palmas_usb->edev->name);
246 
247 	return 0;
248 }
249 
250 #ifdef CONFIG_PM_SLEEP
251 static int palmas_usb_suspend(struct device *dev)
252 {
253 	struct palmas_usb *palmas_usb = dev_get_drvdata(dev);
254 
255 	if (device_may_wakeup(dev)) {
256 		if (palmas_usb->enable_vbus_detection)
257 			enable_irq_wake(palmas_usb->vbus_irq);
258 		if (palmas_usb->enable_id_detection)
259 			enable_irq_wake(palmas_usb->id_irq);
260 	}
261 	return 0;
262 }
263 
264 static int palmas_usb_resume(struct device *dev)
265 {
266 	struct palmas_usb *palmas_usb = dev_get_drvdata(dev);
267 
268 	if (device_may_wakeup(dev)) {
269 		if (palmas_usb->enable_vbus_detection)
270 			disable_irq_wake(palmas_usb->vbus_irq);
271 		if (palmas_usb->enable_id_detection)
272 			disable_irq_wake(palmas_usb->id_irq);
273 	}
274 	return 0;
275 };
276 #endif
277 
278 static SIMPLE_DEV_PM_OPS(palmas_pm_ops, palmas_usb_suspend, palmas_usb_resume);
279 
280 static const struct of_device_id of_palmas_match_tbl[] = {
281 	{ .compatible = "ti,palmas-usb", },
282 	{ .compatible = "ti,palmas-usb-vid", },
283 	{ .compatible = "ti,twl6035-usb", },
284 	{ .compatible = "ti,twl6035-usb-vid", },
285 	{ /* end */ }
286 };
287 
288 static struct platform_driver palmas_usb_driver = {
289 	.probe = palmas_usb_probe,
290 	.remove = palmas_usb_remove,
291 	.driver = {
292 		.name = "palmas-usb",
293 		.of_match_table = of_palmas_match_tbl,
294 		.pm = &palmas_pm_ops,
295 	},
296 };
297 
298 module_platform_driver(palmas_usb_driver);
299 
300 MODULE_ALIAS("platform:palmas-usb");
301 MODULE_AUTHOR("Graeme Gregory <gg@slimlogic.co.uk>");
302 MODULE_DESCRIPTION("Palmas USB transceiver driver");
303 MODULE_LICENSE("GPL");
304 MODULE_DEVICE_TABLE(of, of_palmas_match_tbl);
305