1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * TM2 touchkey device driver
4 *
5 * Copyright 2005 Phil Blundell
6 * Copyright 2016 Samsung Electronics Co., Ltd.
7 *
8 * Author: Beomho Seo <beomho.seo@samsung.com>
9 * Author: Jaechul Lee <jcsing.lee@samsung.com>
10 */
11
12 #include <linux/bitops.h>
13 #include <linux/delay.h>
14 #include <linux/device.h>
15 #include <linux/i2c.h>
16 #include <linux/input.h>
17 #include <linux/interrupt.h>
18 #include <linux/irq.h>
19 #include <linux/leds.h>
20 #include <linux/module.h>
21 #include <linux/of.h>
22 #include <linux/of_device.h>
23 #include <linux/pm.h>
24 #include <linux/regulator/consumer.h>
25
26 #define TM2_TOUCHKEY_DEV_NAME "tm2-touchkey"
27
28 #define ARIES_TOUCHKEY_CMD_LED_ON 0x1
29 #define ARIES_TOUCHKEY_CMD_LED_OFF 0x2
30 #define TM2_TOUCHKEY_CMD_LED_ON 0x10
31 #define TM2_TOUCHKEY_CMD_LED_OFF 0x20
32 #define TM2_TOUCHKEY_BIT_PRESS_EV BIT(3)
33 #define TM2_TOUCHKEY_BIT_KEYCODE GENMASK(2, 0)
34 #define TM2_TOUCHKEY_LED_VOLTAGE_MIN 2500000
35 #define TM2_TOUCHKEY_LED_VOLTAGE_MAX 3300000
36
37 struct touchkey_variant {
38 u8 keycode_reg;
39 u8 base_reg;
40 u8 cmd_led_on;
41 u8 cmd_led_off;
42 bool no_reg;
43 bool fixed_regulator;
44 };
45
46 struct tm2_touchkey_data {
47 struct i2c_client *client;
48 struct input_dev *input_dev;
49 struct led_classdev led_dev;
50 struct regulator *vdd;
51 struct regulator_bulk_data regulators[3];
52 const struct touchkey_variant *variant;
53 u32 keycodes[4];
54 int num_keycodes;
55 };
56
57 static const struct touchkey_variant tm2_touchkey_variant = {
58 .keycode_reg = 0x03,
59 .base_reg = 0x00,
60 .cmd_led_on = TM2_TOUCHKEY_CMD_LED_ON,
61 .cmd_led_off = TM2_TOUCHKEY_CMD_LED_OFF,
62 };
63
64 static const struct touchkey_variant midas_touchkey_variant = {
65 .keycode_reg = 0x00,
66 .base_reg = 0x00,
67 .cmd_led_on = TM2_TOUCHKEY_CMD_LED_ON,
68 .cmd_led_off = TM2_TOUCHKEY_CMD_LED_OFF,
69 };
70
71 static struct touchkey_variant aries_touchkey_variant = {
72 .no_reg = true,
73 .fixed_regulator = true,
74 .cmd_led_on = ARIES_TOUCHKEY_CMD_LED_ON,
75 .cmd_led_off = ARIES_TOUCHKEY_CMD_LED_OFF,
76 };
77
78 static const struct touchkey_variant tc360_touchkey_variant = {
79 .keycode_reg = 0x00,
80 .base_reg = 0x00,
81 .fixed_regulator = true,
82 .cmd_led_on = TM2_TOUCHKEY_CMD_LED_ON,
83 .cmd_led_off = TM2_TOUCHKEY_CMD_LED_OFF,
84 };
85
tm2_touchkey_led_brightness_set(struct led_classdev * led_dev,enum led_brightness brightness)86 static int tm2_touchkey_led_brightness_set(struct led_classdev *led_dev,
87 enum led_brightness brightness)
88 {
89 struct tm2_touchkey_data *touchkey =
90 container_of(led_dev, struct tm2_touchkey_data, led_dev);
91 u32 volt;
92 u8 data;
93
94 if (brightness == LED_OFF) {
95 volt = TM2_TOUCHKEY_LED_VOLTAGE_MIN;
96 data = touchkey->variant->cmd_led_off;
97 } else {
98 volt = TM2_TOUCHKEY_LED_VOLTAGE_MAX;
99 data = touchkey->variant->cmd_led_on;
100 }
101
102 if (!touchkey->variant->fixed_regulator)
103 regulator_set_voltage(touchkey->vdd, volt, volt);
104
105 return touchkey->variant->no_reg ?
106 i2c_smbus_write_byte(touchkey->client, data) :
107 i2c_smbus_write_byte_data(touchkey->client,
108 touchkey->variant->base_reg, data);
109 }
110
tm2_touchkey_power_enable(struct tm2_touchkey_data * touchkey)111 static int tm2_touchkey_power_enable(struct tm2_touchkey_data *touchkey)
112 {
113 int error;
114
115 error = regulator_bulk_enable(ARRAY_SIZE(touchkey->regulators),
116 touchkey->regulators);
117 if (error)
118 return error;
119
120 /* waiting for device initialization, at least 150ms */
121 msleep(150);
122
123 return 0;
124 }
125
tm2_touchkey_power_disable(void * data)126 static void tm2_touchkey_power_disable(void *data)
127 {
128 struct tm2_touchkey_data *touchkey = data;
129
130 regulator_bulk_disable(ARRAY_SIZE(touchkey->regulators),
131 touchkey->regulators);
132 }
133
tm2_touchkey_irq_handler(int irq,void * devid)134 static irqreturn_t tm2_touchkey_irq_handler(int irq, void *devid)
135 {
136 struct tm2_touchkey_data *touchkey = devid;
137 int data;
138 int index;
139 int i;
140
141 if (touchkey->variant->no_reg)
142 data = i2c_smbus_read_byte(touchkey->client);
143 else
144 data = i2c_smbus_read_byte_data(touchkey->client,
145 touchkey->variant->keycode_reg);
146 if (data < 0) {
147 dev_err(&touchkey->client->dev,
148 "failed to read i2c data: %d\n", data);
149 goto out;
150 }
151
152 index = (data & TM2_TOUCHKEY_BIT_KEYCODE) - 1;
153 if (index < 0 || index >= touchkey->num_keycodes) {
154 dev_warn(&touchkey->client->dev,
155 "invalid keycode index %d\n", index);
156 goto out;
157 }
158
159 input_event(touchkey->input_dev, EV_MSC, MSC_SCAN, index);
160
161 if (data & TM2_TOUCHKEY_BIT_PRESS_EV) {
162 for (i = 0; i < touchkey->num_keycodes; i++)
163 input_report_key(touchkey->input_dev,
164 touchkey->keycodes[i], 0);
165 } else {
166 input_report_key(touchkey->input_dev,
167 touchkey->keycodes[index], 1);
168 }
169
170 input_sync(touchkey->input_dev);
171
172 out:
173 if (touchkey->variant->fixed_regulator &&
174 data & TM2_TOUCHKEY_BIT_PRESS_EV) {
175 /* touch turns backlight on, so make sure we're in sync */
176 if (touchkey->led_dev.brightness == LED_OFF)
177 tm2_touchkey_led_brightness_set(&touchkey->led_dev,
178 LED_OFF);
179 }
180
181 return IRQ_HANDLED;
182 }
183
tm2_touchkey_probe(struct i2c_client * client,const struct i2c_device_id * id)184 static int tm2_touchkey_probe(struct i2c_client *client,
185 const struct i2c_device_id *id)
186 {
187 struct device_node *np = client->dev.of_node;
188 struct tm2_touchkey_data *touchkey;
189 int error;
190 int i;
191
192 if (!i2c_check_functionality(client->adapter,
193 I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA)) {
194 dev_err(&client->dev, "incompatible I2C adapter\n");
195 return -EIO;
196 }
197
198 touchkey = devm_kzalloc(&client->dev, sizeof(*touchkey), GFP_KERNEL);
199 if (!touchkey)
200 return -ENOMEM;
201
202 touchkey->client = client;
203 i2c_set_clientdata(client, touchkey);
204
205 touchkey->variant = of_device_get_match_data(&client->dev);
206
207 touchkey->regulators[0].supply = "vcc";
208 touchkey->regulators[1].supply = "vdd";
209 touchkey->regulators[2].supply = "vddio";
210 error = devm_regulator_bulk_get(&client->dev,
211 ARRAY_SIZE(touchkey->regulators),
212 touchkey->regulators);
213 if (error) {
214 dev_err(&client->dev, "failed to get regulators: %d\n", error);
215 return error;
216 }
217
218 /* Save VDD for easy access */
219 touchkey->vdd = touchkey->regulators[1].consumer;
220
221 touchkey->num_keycodes = of_property_read_variable_u32_array(np,
222 "linux,keycodes", touchkey->keycodes, 0,
223 ARRAY_SIZE(touchkey->keycodes));
224 if (touchkey->num_keycodes <= 0) {
225 /* default keycodes */
226 touchkey->keycodes[0] = KEY_PHONE;
227 touchkey->keycodes[1] = KEY_BACK;
228 touchkey->num_keycodes = 2;
229 }
230
231 error = tm2_touchkey_power_enable(touchkey);
232 if (error) {
233 dev_err(&client->dev, "failed to power up device: %d\n", error);
234 return error;
235 }
236
237 error = devm_add_action_or_reset(&client->dev,
238 tm2_touchkey_power_disable, touchkey);
239 if (error) {
240 dev_err(&client->dev,
241 "failed to install poweroff handler: %d\n", error);
242 return error;
243 }
244
245 /* input device */
246 touchkey->input_dev = devm_input_allocate_device(&client->dev);
247 if (!touchkey->input_dev) {
248 dev_err(&client->dev, "failed to allocate input device\n");
249 return -ENOMEM;
250 }
251
252 touchkey->input_dev->name = TM2_TOUCHKEY_DEV_NAME;
253 touchkey->input_dev->id.bustype = BUS_I2C;
254
255 touchkey->input_dev->keycode = touchkey->keycodes;
256 touchkey->input_dev->keycodemax = touchkey->num_keycodes;
257 touchkey->input_dev->keycodesize = sizeof(touchkey->keycodes[0]);
258
259 input_set_capability(touchkey->input_dev, EV_MSC, MSC_SCAN);
260 for (i = 0; i < touchkey->num_keycodes; i++)
261 input_set_capability(touchkey->input_dev, EV_KEY,
262 touchkey->keycodes[i]);
263
264 error = input_register_device(touchkey->input_dev);
265 if (error) {
266 dev_err(&client->dev,
267 "failed to register input device: %d\n", error);
268 return error;
269 }
270
271 error = devm_request_threaded_irq(&client->dev, client->irq,
272 NULL, tm2_touchkey_irq_handler,
273 IRQF_ONESHOT,
274 TM2_TOUCHKEY_DEV_NAME, touchkey);
275 if (error) {
276 dev_err(&client->dev,
277 "failed to request threaded irq: %d\n", error);
278 return error;
279 }
280
281 /* led device */
282 touchkey->led_dev.name = TM2_TOUCHKEY_DEV_NAME;
283 touchkey->led_dev.brightness = LED_ON;
284 touchkey->led_dev.max_brightness = LED_ON;
285 touchkey->led_dev.brightness_set_blocking =
286 tm2_touchkey_led_brightness_set;
287
288 error = devm_led_classdev_register(&client->dev, &touchkey->led_dev);
289 if (error) {
290 dev_err(&client->dev,
291 "failed to register touchkey led: %d\n", error);
292 return error;
293 }
294
295 if (touchkey->variant->fixed_regulator)
296 tm2_touchkey_led_brightness_set(&touchkey->led_dev, LED_ON);
297
298 return 0;
299 }
300
tm2_touchkey_suspend(struct device * dev)301 static int __maybe_unused tm2_touchkey_suspend(struct device *dev)
302 {
303 struct i2c_client *client = to_i2c_client(dev);
304 struct tm2_touchkey_data *touchkey = i2c_get_clientdata(client);
305
306 disable_irq(client->irq);
307 tm2_touchkey_power_disable(touchkey);
308
309 return 0;
310 }
311
tm2_touchkey_resume(struct device * dev)312 static int __maybe_unused tm2_touchkey_resume(struct device *dev)
313 {
314 struct i2c_client *client = to_i2c_client(dev);
315 struct tm2_touchkey_data *touchkey = i2c_get_clientdata(client);
316 int ret;
317
318 enable_irq(client->irq);
319
320 ret = tm2_touchkey_power_enable(touchkey);
321 if (ret)
322 dev_err(dev, "failed to enable power: %d\n", ret);
323
324 return ret;
325 }
326
327 static SIMPLE_DEV_PM_OPS(tm2_touchkey_pm_ops,
328 tm2_touchkey_suspend, tm2_touchkey_resume);
329
330 static const struct i2c_device_id tm2_touchkey_id_table[] = {
331 { TM2_TOUCHKEY_DEV_NAME, 0 },
332 { },
333 };
334 MODULE_DEVICE_TABLE(i2c, tm2_touchkey_id_table);
335
336 static const struct of_device_id tm2_touchkey_of_match[] = {
337 {
338 .compatible = "cypress,tm2-touchkey",
339 .data = &tm2_touchkey_variant,
340 }, {
341 .compatible = "cypress,midas-touchkey",
342 .data = &midas_touchkey_variant,
343 }, {
344 .compatible = "cypress,aries-touchkey",
345 .data = &aries_touchkey_variant,
346 }, {
347 .compatible = "coreriver,tc360-touchkey",
348 .data = &tc360_touchkey_variant,
349 },
350 { },
351 };
352 MODULE_DEVICE_TABLE(of, tm2_touchkey_of_match);
353
354 static struct i2c_driver tm2_touchkey_driver = {
355 .driver = {
356 .name = TM2_TOUCHKEY_DEV_NAME,
357 .pm = &tm2_touchkey_pm_ops,
358 .of_match_table = of_match_ptr(tm2_touchkey_of_match),
359 },
360 .probe = tm2_touchkey_probe,
361 .id_table = tm2_touchkey_id_table,
362 };
363 module_i2c_driver(tm2_touchkey_driver);
364
365 MODULE_AUTHOR("Beomho Seo <beomho.seo@samsung.com>");
366 MODULE_AUTHOR("Jaechul Lee <jcsing.lee@samsung.com>");
367 MODULE_DESCRIPTION("Samsung touchkey driver");
368 MODULE_LICENSE("GPL v2");
369