1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * extcon-fsa9480.c - Fairchild Semiconductor FSA9480 extcon driver
4  *
5  * Copyright (c) 2019 Tomasz Figa <tomasz.figa@gmail.com>
6  *
7  * Loosely based on old fsa9480 misc-device driver.
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/types.h>
13 #include <linux/i2c.h>
14 #include <linux/slab.h>
15 #include <linux/bitops.h>
16 #include <linux/interrupt.h>
17 #include <linux/err.h>
18 #include <linux/platform_device.h>
19 #include <linux/kobject.h>
20 #include <linux/extcon-provider.h>
21 #include <linux/irqdomain.h>
22 #include <linux/regmap.h>
23 
24 /* FSA9480 I2C registers */
25 #define FSA9480_REG_DEVID               0x01
26 #define FSA9480_REG_CTRL                0x02
27 #define FSA9480_REG_INT1                0x03
28 #define FSA9480_REG_INT2                0x04
29 #define FSA9480_REG_INT1_MASK           0x05
30 #define FSA9480_REG_INT2_MASK           0x06
31 #define FSA9480_REG_ADC                 0x07
32 #define FSA9480_REG_TIMING1             0x08
33 #define FSA9480_REG_TIMING2             0x09
34 #define FSA9480_REG_DEV_T1              0x0a
35 #define FSA9480_REG_DEV_T2              0x0b
36 #define FSA9480_REG_BTN1                0x0c
37 #define FSA9480_REG_BTN2                0x0d
38 #define FSA9480_REG_CK                  0x0e
39 #define FSA9480_REG_CK_INT1             0x0f
40 #define FSA9480_REG_CK_INT2             0x10
41 #define FSA9480_REG_CK_INTMASK1         0x11
42 #define FSA9480_REG_CK_INTMASK2         0x12
43 #define FSA9480_REG_MANSW1              0x13
44 #define FSA9480_REG_MANSW2              0x14
45 #define FSA9480_REG_END                 0x15
46 
47 /* Control */
48 #define CON_SWITCH_OPEN         (1 << 4)
49 #define CON_RAW_DATA            (1 << 3)
50 #define CON_MANUAL_SW           (1 << 2)
51 #define CON_WAIT                (1 << 1)
52 #define CON_INT_MASK            (1 << 0)
53 #define CON_MASK                (CON_SWITCH_OPEN | CON_RAW_DATA | \
54 				 CON_MANUAL_SW | CON_WAIT)
55 
56 /* Device Type 1 */
57 #define DEV_USB_OTG             7
58 #define DEV_DEDICATED_CHG       6
59 #define DEV_USB_CHG             5
60 #define DEV_CAR_KIT             4
61 #define DEV_UART                3
62 #define DEV_USB                 2
63 #define DEV_AUDIO_2             1
64 #define DEV_AUDIO_1             0
65 
66 #define DEV_T1_USB_MASK         (DEV_USB_OTG | DEV_USB)
67 #define DEV_T1_UART_MASK        (DEV_UART)
68 #define DEV_T1_CHARGER_MASK     (DEV_DEDICATED_CHG | DEV_USB_CHG)
69 
70 /* Device Type 2 */
71 #define DEV_AV                  14
72 #define DEV_TTY                 13
73 #define DEV_PPD                 12
74 #define DEV_JIG_UART_OFF        11
75 #define DEV_JIG_UART_ON         10
76 #define DEV_JIG_USB_OFF         9
77 #define DEV_JIG_USB_ON          8
78 
79 #define DEV_T2_USB_MASK         (DEV_JIG_USB_OFF | DEV_JIG_USB_ON)
80 #define DEV_T2_UART_MASK        (DEV_JIG_UART_OFF | DEV_JIG_UART_ON)
81 #define DEV_T2_JIG_MASK         (DEV_JIG_USB_OFF | DEV_JIG_USB_ON | \
82 				 DEV_JIG_UART_OFF | DEV_JIG_UART_ON)
83 
84 /*
85  * Manual Switch
86  * D- [7:5] / D+ [4:2]
87  * 000: Open all / 001: USB / 010: AUDIO / 011: UART / 100: V_AUDIO
88  */
89 #define SW_VAUDIO               ((4 << 5) | (4 << 2))
90 #define SW_UART                 ((3 << 5) | (3 << 2))
91 #define SW_AUDIO                ((2 << 5) | (2 << 2))
92 #define SW_DHOST                ((1 << 5) | (1 << 2))
93 #define SW_AUTO                 ((0 << 5) | (0 << 2))
94 
95 /* Interrupt 1 */
96 #define INT1_MASK               (0xff << 0)
97 #define INT_DETACH              (1 << 1)
98 #define INT_ATTACH              (1 << 0)
99 
100 /* Interrupt 2 mask */
101 #define INT2_MASK               (0x1f << 0)
102 
103 /* Timing Set 1 */
104 #define TIMING1_ADC_500MS       (0x6 << 0)
105 
106 struct fsa9480_usbsw {
107 	struct device *dev;
108 	struct regmap *regmap;
109 	struct extcon_dev *edev;
110 	u16 cable;
111 };
112 
113 static const unsigned int fsa9480_extcon_cable[] = {
114 	EXTCON_USB_HOST,
115 	EXTCON_USB,
116 	EXTCON_CHG_USB_DCP,
117 	EXTCON_CHG_USB_SDP,
118 	EXTCON_CHG_USB_ACA,
119 	EXTCON_JACK_LINE_OUT,
120 	EXTCON_JACK_VIDEO_OUT,
121 	EXTCON_JIG,
122 
123 	EXTCON_NONE,
124 };
125 
126 static const u64 cable_types[] = {
127 	[DEV_USB_OTG] = BIT_ULL(EXTCON_USB_HOST),
128 	[DEV_DEDICATED_CHG] = BIT_ULL(EXTCON_USB) | BIT_ULL(EXTCON_CHG_USB_DCP),
129 	[DEV_USB_CHG] = BIT_ULL(EXTCON_USB) | BIT_ULL(EXTCON_CHG_USB_SDP),
130 	[DEV_CAR_KIT] = BIT_ULL(EXTCON_USB) | BIT_ULL(EXTCON_CHG_USB_SDP)
131 			| BIT_ULL(EXTCON_JACK_LINE_OUT),
132 	[DEV_UART] = BIT_ULL(EXTCON_JIG),
133 	[DEV_USB] = BIT_ULL(EXTCON_USB) | BIT_ULL(EXTCON_CHG_USB_SDP),
134 	[DEV_AUDIO_2] = BIT_ULL(EXTCON_JACK_LINE_OUT),
135 	[DEV_AUDIO_1] = BIT_ULL(EXTCON_JACK_LINE_OUT),
136 	[DEV_AV] = BIT_ULL(EXTCON_JACK_LINE_OUT)
137 		   | BIT_ULL(EXTCON_JACK_VIDEO_OUT),
138 	[DEV_TTY] = BIT_ULL(EXTCON_JIG),
139 	[DEV_PPD] = BIT_ULL(EXTCON_JACK_LINE_OUT) | BIT_ULL(EXTCON_CHG_USB_ACA),
140 	[DEV_JIG_UART_OFF] = BIT_ULL(EXTCON_JIG),
141 	[DEV_JIG_UART_ON] = BIT_ULL(EXTCON_JIG),
142 	[DEV_JIG_USB_OFF] = BIT_ULL(EXTCON_USB) | BIT_ULL(EXTCON_JIG),
143 	[DEV_JIG_USB_ON] = BIT_ULL(EXTCON_USB) | BIT_ULL(EXTCON_JIG),
144 };
145 
146 /* Define regmap configuration of FSA9480 for I2C communication  */
147 static bool fsa9480_volatile_reg(struct device *dev, unsigned int reg)
148 {
149 	switch (reg) {
150 	case FSA9480_REG_INT1_MASK:
151 		return true;
152 	default:
153 		break;
154 	}
155 	return false;
156 }
157 
158 static const struct regmap_config fsa9480_regmap_config = {
159 	.reg_bits	= 8,
160 	.val_bits	= 8,
161 	.volatile_reg	= fsa9480_volatile_reg,
162 	.max_register	= FSA9480_REG_END,
163 };
164 
165 static int fsa9480_write_reg(struct fsa9480_usbsw *usbsw, int reg, int value)
166 {
167 	int ret;
168 
169 	ret = regmap_write(usbsw->regmap, reg, value);
170 	if (ret < 0)
171 		dev_err(usbsw->dev, "%s: err %d\n", __func__, ret);
172 
173 	return ret;
174 }
175 
176 static int fsa9480_read_reg(struct fsa9480_usbsw *usbsw, int reg)
177 {
178 	int ret, val;
179 
180 	ret = regmap_read(usbsw->regmap, reg, &val);
181 	if (ret < 0) {
182 		dev_err(usbsw->dev, "%s: err %d\n", __func__, ret);
183 		return ret;
184 	}
185 
186 	return val;
187 }
188 
189 static int fsa9480_read_irq(struct fsa9480_usbsw *usbsw, int *value)
190 {
191 	u8 regs[2];
192 	int ret;
193 
194 	ret = regmap_bulk_read(usbsw->regmap, FSA9480_REG_INT1, regs, 2);
195 	if (ret < 0)
196 		dev_err(usbsw->dev, "%s: err %d\n", __func__, ret);
197 
198 	*value = regs[1] << 8 | regs[0];
199 	return ret;
200 }
201 
202 static void fsa9480_handle_change(struct fsa9480_usbsw *usbsw,
203 				  u16 mask, bool attached)
204 {
205 	while (mask) {
206 		int dev = fls64(mask) - 1;
207 		u64 cables = cable_types[dev];
208 
209 		while (cables) {
210 			int cable = fls64(cables) - 1;
211 
212 			extcon_set_state_sync(usbsw->edev, cable, attached);
213 			cables &= ~BIT_ULL(cable);
214 		}
215 
216 		mask &= ~BIT_ULL(dev);
217 	}
218 }
219 
220 static void fsa9480_detect_dev(struct fsa9480_usbsw *usbsw)
221 {
222 	int val1, val2;
223 	u16 val;
224 
225 	val1 = fsa9480_read_reg(usbsw, FSA9480_REG_DEV_T1);
226 	val2 = fsa9480_read_reg(usbsw, FSA9480_REG_DEV_T2);
227 	if (val1 < 0 || val2 < 0) {
228 		dev_err(usbsw->dev, "%s: failed to read registers", __func__);
229 		return;
230 	}
231 	val = val2 << 8 | val1;
232 
233 	dev_info(usbsw->dev, "dev1: 0x%x, dev2: 0x%x\n", val1, val2);
234 
235 	/* handle detached cables first */
236 	fsa9480_handle_change(usbsw, usbsw->cable & ~val, false);
237 
238 	/* then handle attached ones */
239 	fsa9480_handle_change(usbsw, val & ~usbsw->cable, true);
240 
241 	usbsw->cable = val;
242 }
243 
244 static irqreturn_t fsa9480_irq_handler(int irq, void *data)
245 {
246 	struct fsa9480_usbsw *usbsw = data;
247 	int intr = 0;
248 
249 	/* clear interrupt */
250 	fsa9480_read_irq(usbsw, &intr);
251 	if (!intr)
252 		return IRQ_NONE;
253 
254 	/* device detection */
255 	fsa9480_detect_dev(usbsw);
256 
257 	return IRQ_HANDLED;
258 }
259 
260 static int fsa9480_probe(struct i2c_client *client,
261 			 const struct i2c_device_id *id)
262 {
263 	struct fsa9480_usbsw *info;
264 	int ret;
265 
266 	if (!client->irq) {
267 		dev_err(&client->dev, "no interrupt provided\n");
268 		return -EINVAL;
269 	}
270 
271 	info = devm_kzalloc(&client->dev, sizeof(*info), GFP_KERNEL);
272 	if (!info)
273 		return -ENOMEM;
274 	info->dev = &client->dev;
275 
276 	i2c_set_clientdata(client, info);
277 
278 	/* External connector */
279 	info->edev = devm_extcon_dev_allocate(info->dev,
280 					      fsa9480_extcon_cable);
281 	if (IS_ERR(info->edev)) {
282 		dev_err(info->dev, "failed to allocate memory for extcon\n");
283 		ret = -ENOMEM;
284 		return ret;
285 	}
286 
287 	ret = devm_extcon_dev_register(info->dev, info->edev);
288 	if (ret) {
289 		dev_err(info->dev, "failed to register extcon device\n");
290 		return ret;
291 	}
292 
293 	info->regmap = devm_regmap_init_i2c(client, &fsa9480_regmap_config);
294 	if (IS_ERR(info->regmap)) {
295 		ret = PTR_ERR(info->regmap);
296 		dev_err(info->dev, "failed to allocate register map: %d\n",
297 			ret);
298 		return ret;
299 	}
300 
301 	/* ADC Detect Time: 500ms */
302 	fsa9480_write_reg(info, FSA9480_REG_TIMING1, TIMING1_ADC_500MS);
303 
304 	/* configure automatic switching */
305 	fsa9480_write_reg(info, FSA9480_REG_CTRL, CON_MASK);
306 
307 	/* unmask interrupt (attach/detach only) */
308 	fsa9480_write_reg(info, FSA9480_REG_INT1_MASK,
309 			  INT1_MASK & ~(INT_ATTACH | INT_DETACH));
310 	fsa9480_write_reg(info, FSA9480_REG_INT2_MASK, INT2_MASK);
311 
312 	ret = devm_request_threaded_irq(info->dev, client->irq, NULL,
313 					fsa9480_irq_handler,
314 					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
315 					"fsa9480", info);
316 	if (ret) {
317 		dev_err(info->dev, "failed to request IRQ\n");
318 		return ret;
319 	}
320 
321 	device_init_wakeup(info->dev, true);
322 	fsa9480_detect_dev(info);
323 
324 	return 0;
325 }
326 
327 static int fsa9480_remove(struct i2c_client *client)
328 {
329 	return 0;
330 }
331 
332 #ifdef CONFIG_PM_SLEEP
333 static int fsa9480_suspend(struct device *dev)
334 {
335 	struct i2c_client *client = to_i2c_client(dev);
336 
337 	if (device_may_wakeup(&client->dev) && client->irq)
338 		enable_irq_wake(client->irq);
339 
340 	return 0;
341 }
342 
343 static int fsa9480_resume(struct device *dev)
344 {
345 	struct i2c_client *client = to_i2c_client(dev);
346 
347 	if (device_may_wakeup(&client->dev) && client->irq)
348 		disable_irq_wake(client->irq);
349 
350 	return 0;
351 }
352 #endif
353 
354 static const struct dev_pm_ops fsa9480_pm_ops = {
355 	SET_SYSTEM_SLEEP_PM_OPS(fsa9480_suspend, fsa9480_resume)
356 };
357 
358 static const struct i2c_device_id fsa9480_id[] = {
359 	{ "fsa9480", 0 },
360 	{}
361 };
362 MODULE_DEVICE_TABLE(i2c, fsa9480_id);
363 
364 static const struct of_device_id fsa9480_of_match[] = {
365 	{ .compatible = "fcs,fsa9480", },
366 	{ .compatible = "fcs,fsa880", },
367 	{ .compatible = "ti,tsu6111", },
368 	{ },
369 };
370 MODULE_DEVICE_TABLE(of, fsa9480_of_match);
371 
372 static struct i2c_driver fsa9480_i2c_driver = {
373 	.driver			= {
374 		.name		= "fsa9480",
375 		.pm		= &fsa9480_pm_ops,
376 		.of_match_table = fsa9480_of_match,
377 	},
378 	.probe			= fsa9480_probe,
379 	.remove			= fsa9480_remove,
380 	.id_table		= fsa9480_id,
381 };
382 
383 static int __init fsa9480_module_init(void)
384 {
385 	return i2c_add_driver(&fsa9480_i2c_driver);
386 }
387 subsys_initcall(fsa9480_module_init);
388 
389 static void __exit fsa9480_module_exit(void)
390 {
391 	i2c_del_driver(&fsa9480_i2c_driver);
392 }
393 module_exit(fsa9480_module_exit);
394 
395 MODULE_DESCRIPTION("Fairchild Semiconductor FSA9480 extcon driver");
396 MODULE_AUTHOR("Tomasz Figa <tomasz.figa@gmail.com>");
397 MODULE_LICENSE("GPL");
398