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