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