/drivers/input/touchscreen/st1232.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * ST1232 Touchscreen Controller Driver
  4 *
  5 * Copyright (C) 2010 Renesas Solutions Corp.
  6 *	Tony SIM <chinyeow.sim.xt@renesas.com>
  7 *
  8 * Using code from:
  9 *  - android.git.kernel.org: projects/kernel/common.git: synaptics_i2c_rmi.c
 10 *	Copyright (C) 2007 Google, Inc.
 11 */
 12
 13#include <linux/delay.h>
 14#include <linux/gpio/consumer.h>
 15#include <linux/i2c.h>
 16#include <linux/input.h>
 17#include <linux/input/mt.h>
 18#include <linux/input/touchscreen.h>
 19#include <linux/interrupt.h>
 20#include <linux/module.h>
 21#include <linux/of.h>
 22#include <linux/pm_qos.h>
 23#include <linux/slab.h>
 24#include <linux/types.h>
 25
 26#define ST1232_TS_NAME	"st1232-ts"
 27#define ST1633_TS_NAME	"st1633-ts"
 28
 29#define ST_TS_MAX_FINGERS	10
 30
 31struct st_chip_info {
 32	bool	have_z;
 33	u16	max_x;
 34	u16	max_y;
 35	u16	max_area;
 36	u16	max_fingers;
 37	u8	start_reg;
 38};
 39
 40struct st1232_ts_data {
 41	struct i2c_client *client;
 42	struct input_dev *input_dev;
 43	struct touchscreen_properties prop;
 44	struct dev_pm_qos_request low_latency_req;
 45	struct gpio_desc *reset_gpio;
 46	const struct st_chip_info *chip_info;
 47	int read_buf_len;
 48	u8 *read_buf;
 49};
 50
 51static int st1232_ts_read_data(struct st1232_ts_data *ts)
 52{
 53	struct i2c_client *client = ts->client;
 54	u8 start_reg = ts->chip_info->start_reg;
 55	struct i2c_msg msg[] = {
 56		{
 57			.addr	= client->addr,
 58			.len	= sizeof(start_reg),
 59			.buf	= &start_reg,
 60		},
 61		{
 62			.addr	= client->addr,
 63			.flags	= I2C_M_RD | I2C_M_DMA_SAFE,
 64			.len	= ts->read_buf_len,
 65			.buf	= ts->read_buf,
 66		}
 67	};
 68	int ret;
 69
 70	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
 71	if (ret != ARRAY_SIZE(msg))
 72		return ret < 0 ? ret : -EIO;
 73
 74	return 0;
 75}
 76
 77static int st1232_ts_parse_and_report(struct st1232_ts_data *ts)
 78{
 79	struct input_dev *input = ts->input_dev;
 80	struct input_mt_pos pos[ST_TS_MAX_FINGERS];
 81	u8 z[ST_TS_MAX_FINGERS];
 82	int slots[ST_TS_MAX_FINGERS];
 83	int n_contacts = 0;
 84	int i;
 85
 86	for (i = 0; i < ts->chip_info->max_fingers; i++) {
 87		u8 *buf = &ts->read_buf[i * 4];
 88
 89		if (buf[0] & BIT(7)) {
 90			unsigned int x = ((buf[0] & 0x70) << 4) | buf[1];
 91			unsigned int y = ((buf[0] & 0x07) << 8) | buf[2];
 92
 93			touchscreen_set_mt_pos(&pos[n_contacts],
 94					       &ts->prop, x, y);
 95
 96			/* st1232 includes a z-axis / touch strength */
 97			if (ts->chip_info->have_z)
 98				z[n_contacts] = ts->read_buf[i + 6];
 99
100			n_contacts++;
101		}
102	}
103
104	input_mt_assign_slots(input, slots, pos, n_contacts, 0);
105	for (i = 0; i < n_contacts; i++) {
106		input_mt_slot(input, slots[i]);
107		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
108		input_report_abs(input, ABS_MT_POSITION_X, pos[i].x);
109		input_report_abs(input, ABS_MT_POSITION_Y, pos[i].y);
110		if (ts->chip_info->have_z)
111			input_report_abs(input, ABS_MT_TOUCH_MAJOR, z[i]);
112	}
113
114	input_mt_sync_frame(input);
115	input_sync(input);
116
117	return n_contacts;
118}
119
120static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
121{
122	struct st1232_ts_data *ts = dev_id;
123	int count;
124	int error;
125
126	error = st1232_ts_read_data(ts);
127	if (error)
128		goto out;
129
130	count = st1232_ts_parse_and_report(ts);
131	if (!count) {
132		if (ts->low_latency_req.dev) {
133			dev_pm_qos_remove_request(&ts->low_latency_req);
134			ts->low_latency_req.dev = NULL;
135		}
136	} else if (!ts->low_latency_req.dev) {
137		/* First contact, request 100 us latency. */
138		dev_pm_qos_add_ancestor_request(&ts->client->dev,
139						&ts->low_latency_req,
140						DEV_PM_QOS_RESUME_LATENCY, 100);
141	}
142
143out:
144	return IRQ_HANDLED;
145}
146
147static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron)
148{
149	if (ts->reset_gpio)
150		gpiod_set_value_cansleep(ts->reset_gpio, !poweron);
151}
152
153static void st1232_ts_power_off(void *data)
154{
155	st1232_ts_power(data, false);
156}
157
158static const struct st_chip_info st1232_chip_info = {
159	.have_z		= true,
160	.max_x		= 0x31f, /* 800 - 1 */
161	.max_y		= 0x1df, /* 480 -1 */
162	.max_area	= 0xff,
163	.max_fingers	= 2,
164	.start_reg	= 0x12,
165};
166
167static const struct st_chip_info st1633_chip_info = {
168	.have_z		= false,
169	.max_x		= 0x13f, /* 320 - 1 */
170	.max_y		= 0x1df, /* 480 -1 */
171	.max_area	= 0x00,
172	.max_fingers	= 5,
173	.start_reg	= 0x12,
174};
175
176static int st1232_ts_probe(struct i2c_client *client,
177			   const struct i2c_device_id *id)
178{
179	const struct st_chip_info *match;
180	struct st1232_ts_data *ts;
181	struct input_dev *input_dev;
182	int error;
183
184	match = device_get_match_data(&client->dev);
185	if (!match && id)
186		match = (const void *)id->driver_data;
187	if (!match) {
188		dev_err(&client->dev, "unknown device model\n");
189		return -ENODEV;
190	}
191
192	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
193		dev_err(&client->dev, "need I2C_FUNC_I2C\n");
194		return -EIO;
195	}
196
197	if (!client->irq) {
198		dev_err(&client->dev, "no IRQ?\n");
199		return -EINVAL;
200	}
201
202	ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
203	if (!ts)
204		return -ENOMEM;
205
206	ts->chip_info = match;
207
208	/* allocate a buffer according to the number of registers to read */
209	ts->read_buf_len = ts->chip_info->max_fingers * 4;
210	ts->read_buf = devm_kzalloc(&client->dev, ts->read_buf_len, GFP_KERNEL);
211	if (!ts->read_buf)
212		return -ENOMEM;
213
214	input_dev = devm_input_allocate_device(&client->dev);
215	if (!input_dev)
216		return -ENOMEM;
217
218	ts->client = client;
219	ts->input_dev = input_dev;
220
221	ts->reset_gpio = devm_gpiod_get_optional(&client->dev, NULL,
222						 GPIOD_OUT_HIGH);
223	if (IS_ERR(ts->reset_gpio)) {
224		error = PTR_ERR(ts->reset_gpio);
225		dev_err(&client->dev, "Unable to request GPIO pin: %d.\n",
226			error);
227		return error;
228	}
229
230	st1232_ts_power(ts, true);
231
232	error = devm_add_action_or_reset(&client->dev, st1232_ts_power_off, ts);
233	if (error) {
234		dev_err(&client->dev,
235			"Failed to install power off action: %d\n", error);
236		return error;
237	}
238
239	input_dev->name = "st1232-touchscreen";
240	input_dev->id.bustype = BUS_I2C;
241
242	if (ts->chip_info->have_z)
243		input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
244				     ts->chip_info->max_area, 0, 0);
245
246	input_set_abs_params(input_dev, ABS_MT_POSITION_X,
247			     0, ts->chip_info->max_x, 0, 0);
248	input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
249			     0, ts->chip_info->max_y, 0, 0);
250
251	touchscreen_parse_properties(input_dev, true, &ts->prop);
252
253	error = input_mt_init_slots(input_dev, ts->chip_info->max_fingers,
254				    INPUT_MT_DIRECT | INPUT_MT_TRACK |
255					INPUT_MT_DROP_UNUSED);
256	if (error) {
257		dev_err(&client->dev, "failed to initialize MT slots\n");
258		return error;
259	}
260
261	error = devm_request_threaded_irq(&client->dev, client->irq,
262					  NULL, st1232_ts_irq_handler,
263					  IRQF_ONESHOT,
264					  client->name, ts);
265	if (error) {
266		dev_err(&client->dev, "Failed to register interrupt\n");
267		return error;
268	}
269
270	error = input_register_device(ts->input_dev);
271	if (error) {
272		dev_err(&client->dev, "Unable to register %s input device\n",
273			input_dev->name);
274		return error;
275	}
276
277	i2c_set_clientdata(client, ts);
278
279	return 0;
280}
281
282static int __maybe_unused st1232_ts_suspend(struct device *dev)
283{
284	struct i2c_client *client = to_i2c_client(dev);
285	struct st1232_ts_data *ts = i2c_get_clientdata(client);
286
287	disable_irq(client->irq);
288
289	if (!device_may_wakeup(&client->dev))
290		st1232_ts_power(ts, false);
291
292	return 0;
293}
294
295static int __maybe_unused st1232_ts_resume(struct device *dev)
296{
297	struct i2c_client *client = to_i2c_client(dev);
298	struct st1232_ts_data *ts = i2c_get_clientdata(client);
299
300	if (!device_may_wakeup(&client->dev))
301		st1232_ts_power(ts, true);
302
303	enable_irq(client->irq);
304
305	return 0;
306}
307
308static SIMPLE_DEV_PM_OPS(st1232_ts_pm_ops,
309			 st1232_ts_suspend, st1232_ts_resume);
310
311static const struct i2c_device_id st1232_ts_id[] = {
312	{ ST1232_TS_NAME, (unsigned long)&st1232_chip_info },
313	{ ST1633_TS_NAME, (unsigned long)&st1633_chip_info },
314	{ }
315};
316MODULE_DEVICE_TABLE(i2c, st1232_ts_id);
317
318static const struct of_device_id st1232_ts_dt_ids[] = {
319	{ .compatible = "sitronix,st1232", .data = &st1232_chip_info },
320	{ .compatible = "sitronix,st1633", .data = &st1633_chip_info },
321	{ }
322};
323MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids);
324
325static struct i2c_driver st1232_ts_driver = {
326	.probe		= st1232_ts_probe,
327	.id_table	= st1232_ts_id,
328	.driver = {
329		.name	= ST1232_TS_NAME,
330		.of_match_table = st1232_ts_dt_ids,
331		.pm	= &st1232_ts_pm_ops,
332	},
333};
334
335module_i2c_driver(st1232_ts_driver);
336
337MODULE_AUTHOR("Tony SIM <chinyeow.sim.xt@renesas.com>");
338MODULE_AUTHOR("Martin Kepplinger <martin.kepplinger@ginzinger.com>");
339MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver");
340MODULE_LICENSE("GPL v2");