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  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
 37struct 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
 46struct 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
 57static 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
 64static 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
 71static 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
 78static 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
 86static 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
111static 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
126static 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
134static 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
172out:
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
184static int tm2_touchkey_probe(struct i2c_client *client)
185{
186	struct device_node *np = client->dev.of_node;
187	struct tm2_touchkey_data *touchkey;
188	int error;
189	int i;
190
191	if (!i2c_check_functionality(client->adapter,
192			I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA)) {
193		dev_err(&client->dev, "incompatible I2C adapter\n");
194		return -EIO;
195	}
196
197	touchkey = devm_kzalloc(&client->dev, sizeof(*touchkey), GFP_KERNEL);
198	if (!touchkey)
199		return -ENOMEM;
200
201	touchkey->client = client;
202	i2c_set_clientdata(client, touchkey);
203
204	touchkey->variant = of_device_get_match_data(&client->dev);
205
206	touchkey->regulators[0].supply = "vcc";
207	touchkey->regulators[1].supply = "vdd";
208	touchkey->regulators[2].supply = "vddio";
209	error = devm_regulator_bulk_get(&client->dev,
210					ARRAY_SIZE(touchkey->regulators),
211					touchkey->regulators);
212	if (error) {
213		dev_err(&client->dev, "failed to get regulators: %d\n", error);
214		return error;
215	}
216
217	/* Save VDD for easy access */
218	touchkey->vdd = touchkey->regulators[1].consumer;
219
220	touchkey->num_keycodes = of_property_read_variable_u32_array(np,
221					"linux,keycodes", touchkey->keycodes, 0,
222					ARRAY_SIZE(touchkey->keycodes));
223	if (touchkey->num_keycodes <= 0) {
224		/* default keycodes */
225		touchkey->keycodes[0] = KEY_PHONE;
226		touchkey->keycodes[1] = KEY_BACK;
227		touchkey->num_keycodes = 2;
228	}
229
230	error = tm2_touchkey_power_enable(touchkey);
231	if (error) {
232		dev_err(&client->dev, "failed to power up device: %d\n", error);
233		return error;
234	}
235
236	error = devm_add_action_or_reset(&client->dev,
237					 tm2_touchkey_power_disable, touchkey);
238	if (error) {
239		dev_err(&client->dev,
240			"failed to install poweroff handler: %d\n", error);
241		return error;
242	}
243
244	/* input device */
245	touchkey->input_dev = devm_input_allocate_device(&client->dev);
246	if (!touchkey->input_dev) {
247		dev_err(&client->dev, "failed to allocate input device\n");
248		return -ENOMEM;
249	}
250
251	touchkey->input_dev->name = TM2_TOUCHKEY_DEV_NAME;
252	touchkey->input_dev->id.bustype = BUS_I2C;
253
254	touchkey->input_dev->keycode = touchkey->keycodes;
255	touchkey->input_dev->keycodemax = touchkey->num_keycodes;
256	touchkey->input_dev->keycodesize = sizeof(touchkey->keycodes[0]);
257
258	input_set_capability(touchkey->input_dev, EV_MSC, MSC_SCAN);
259	for (i = 0; i < touchkey->num_keycodes; i++)
260		input_set_capability(touchkey->input_dev, EV_KEY,
261				     touchkey->keycodes[i]);
262
263	error = input_register_device(touchkey->input_dev);
264	if (error) {
265		dev_err(&client->dev,
266			"failed to register input device: %d\n", error);
267		return error;
268	}
269
270	error = devm_request_threaded_irq(&client->dev, client->irq,
271					  NULL, tm2_touchkey_irq_handler,
272					  IRQF_ONESHOT,
273					  TM2_TOUCHKEY_DEV_NAME, touchkey);
274	if (error) {
275		dev_err(&client->dev,
276			"failed to request threaded irq: %d\n", error);
277		return error;
278	}
279
280	/* led device */
281	touchkey->led_dev.name = TM2_TOUCHKEY_DEV_NAME;
282	touchkey->led_dev.brightness = LED_ON;
283	touchkey->led_dev.max_brightness = LED_ON;
284	touchkey->led_dev.brightness_set_blocking =
285					tm2_touchkey_led_brightness_set;
286
287	error = devm_led_classdev_register(&client->dev, &touchkey->led_dev);
288	if (error) {
289		dev_err(&client->dev,
290			"failed to register touchkey led: %d\n", error);
291		return error;
292	}
293
294	if (touchkey->variant->fixed_regulator)
295		tm2_touchkey_led_brightness_set(&touchkey->led_dev, LED_ON);
296
297	return 0;
298}
299
300static int tm2_touchkey_suspend(struct device *dev)
301{
302	struct i2c_client *client = to_i2c_client(dev);
303	struct tm2_touchkey_data *touchkey = i2c_get_clientdata(client);
304
305	disable_irq(client->irq);
306	tm2_touchkey_power_disable(touchkey);
307
308	return 0;
309}
310
311static int tm2_touchkey_resume(struct device *dev)
312{
313	struct i2c_client *client = to_i2c_client(dev);
314	struct tm2_touchkey_data *touchkey = i2c_get_clientdata(client);
315	int ret;
316
317	enable_irq(client->irq);
318
319	ret = tm2_touchkey_power_enable(touchkey);
320	if (ret)
321		dev_err(dev, "failed to enable power: %d\n", ret);
322
323	return ret;
324}
325
326static DEFINE_SIMPLE_DEV_PM_OPS(tm2_touchkey_pm_ops,
327				tm2_touchkey_suspend, tm2_touchkey_resume);
328
329static const struct i2c_device_id tm2_touchkey_id_table[] = {
330	{ TM2_TOUCHKEY_DEV_NAME, 0 },
331	{ },
332};
333MODULE_DEVICE_TABLE(i2c, tm2_touchkey_id_table);
334
335static const struct of_device_id tm2_touchkey_of_match[] = {
336	{
337		.compatible = "cypress,tm2-touchkey",
338		.data = &tm2_touchkey_variant,
339	}, {
340		.compatible = "cypress,midas-touchkey",
341		.data = &midas_touchkey_variant,
342	}, {
343		.compatible = "cypress,aries-touchkey",
344		.data = &aries_touchkey_variant,
345	}, {
346		.compatible = "coreriver,tc360-touchkey",
347		.data = &tc360_touchkey_variant,
348	},
349	{ },
350};
351MODULE_DEVICE_TABLE(of, tm2_touchkey_of_match);
352
353static struct i2c_driver tm2_touchkey_driver = {
354	.driver = {
355		.name = TM2_TOUCHKEY_DEV_NAME,
356		.pm = pm_sleep_ptr(&tm2_touchkey_pm_ops),
357		.of_match_table = of_match_ptr(tm2_touchkey_of_match),
358	},
359	.probe_new = tm2_touchkey_probe,
360	.id_table = tm2_touchkey_id_table,
361};
362module_i2c_driver(tm2_touchkey_driver);
363
364MODULE_AUTHOR("Beomho Seo <beomho.seo@samsung.com>");
365MODULE_AUTHOR("Jaechul Lee <jcsing.lee@samsung.com>");
366MODULE_DESCRIPTION("Samsung touchkey driver");
367MODULE_LICENSE("GPL v2");