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