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 REG_STATUS		0x01	/* Device Status | Error Code */
30
31#define STATUS_NORMAL		0x00
32#define STATUS_INIT		0x01
33#define STATUS_ERROR		0x02
34#define STATUS_AUTO_TUNING	0x03
35#define STATUS_IDLE		0x04
36#define STATUS_POWER_DOWN	0x05
37
38#define ERROR_NONE		0x00
39#define ERROR_INVALID_ADDRESS	0x10
40#define ERROR_INVALID_VALUE	0x20
41#define ERROR_INVALID_PLATFORM	0x30
42
43#define REG_XY_RESOLUTION	0x04
44#define REG_XY_COORDINATES	0x12
45#define ST_TS_MAX_FINGERS	10
46
47struct st_chip_info {
48	bool	have_z;
49	u16	max_area;
50	u16	max_fingers;
51};
52
53struct st1232_ts_data {
54	struct i2c_client *client;
55	struct input_dev *input_dev;
56	struct touchscreen_properties prop;
57	struct dev_pm_qos_request low_latency_req;
58	struct gpio_desc *reset_gpio;
59	const struct st_chip_info *chip_info;
60	int read_buf_len;
61	u8 *read_buf;
62};
63
64static int st1232_ts_read_data(struct st1232_ts_data *ts, u8 reg,
65			       unsigned int n)
66{
67	struct i2c_client *client = ts->client;
68	struct i2c_msg msg[] = {
69		{
70			.addr	= client->addr,
71			.len	= sizeof(reg),
72			.buf	= &reg,
73		},
74		{
75			.addr	= client->addr,
76			.flags	= I2C_M_RD | I2C_M_DMA_SAFE,
77			.len	= n,
78			.buf	= ts->read_buf,
79		}
80	};
81	int ret;
82
83	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
84	if (ret != ARRAY_SIZE(msg))
85		return ret < 0 ? ret : -EIO;
86
87	return 0;
88}
89
90static int st1232_ts_wait_ready(struct st1232_ts_data *ts)
91{
92	unsigned int retries;
93	int error;
94
95	for (retries = 100; retries; retries--) {
96		error = st1232_ts_read_data(ts, REG_STATUS, 1);
97		if (!error) {
98			switch (ts->read_buf[0]) {
99			case STATUS_NORMAL | ERROR_NONE:
100			case STATUS_IDLE | ERROR_NONE:
101				return 0;
102			}
103		}
104
105		usleep_range(1000, 2000);
106	}
107
108	return -ENXIO;
109}
110
111static int st1232_ts_read_resolution(struct st1232_ts_data *ts, u16 *max_x,
112				     u16 *max_y)
113{
114	u8 *buf;
115	int error;
116
117	/* select resolution register */
118	error = st1232_ts_read_data(ts, REG_XY_RESOLUTION, 3);
119	if (error)
120		return error;
121
122	buf = ts->read_buf;
123
124	*max_x = (((buf[0] & 0x0070) << 4) | buf[1]) - 1;
125	*max_y = (((buf[0] & 0x0007) << 8) | buf[2]) - 1;
126
127	return 0;
128}
129
130static int st1232_ts_parse_and_report(struct st1232_ts_data *ts)
131{
132	struct input_dev *input = ts->input_dev;
133	struct input_mt_pos pos[ST_TS_MAX_FINGERS];
134	u8 z[ST_TS_MAX_FINGERS];
135	int slots[ST_TS_MAX_FINGERS];
136	int n_contacts = 0;
137	int i;
138
139	for (i = 0; i < ts->chip_info->max_fingers; i++) {
140		u8 *buf = &ts->read_buf[i * 4];
141
142		if (buf[0] & BIT(7)) {
143			unsigned int x = ((buf[0] & 0x70) << 4) | buf[1];
144			unsigned int y = ((buf[0] & 0x07) << 8) | buf[2];
145
146			touchscreen_set_mt_pos(&pos[n_contacts],
147					       &ts->prop, x, y);
148
149			/* st1232 includes a z-axis / touch strength */
150			if (ts->chip_info->have_z)
151				z[n_contacts] = ts->read_buf[i + 6];
152
153			n_contacts++;
154		}
155	}
156
157	input_mt_assign_slots(input, slots, pos, n_contacts, 0);
158	for (i = 0; i < n_contacts; i++) {
159		input_mt_slot(input, slots[i]);
160		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
161		input_report_abs(input, ABS_MT_POSITION_X, pos[i].x);
162		input_report_abs(input, ABS_MT_POSITION_Y, pos[i].y);
163		if (ts->chip_info->have_z)
164			input_report_abs(input, ABS_MT_TOUCH_MAJOR, z[i]);
165	}
166
167	input_mt_sync_frame(input);
168	input_sync(input);
169
170	return n_contacts;
171}
172
173static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
174{
175	struct st1232_ts_data *ts = dev_id;
176	int count;
177	int error;
178
179	error = st1232_ts_read_data(ts, REG_XY_COORDINATES, ts->read_buf_len);
180	if (error)
181		goto out;
182
183	count = st1232_ts_parse_and_report(ts);
184	if (!count) {
185		if (ts->low_latency_req.dev) {
186			dev_pm_qos_remove_request(&ts->low_latency_req);
187			ts->low_latency_req.dev = NULL;
188		}
189	} else if (!ts->low_latency_req.dev) {
190		/* First contact, request 100 us latency. */
191		dev_pm_qos_add_ancestor_request(&ts->client->dev,
192						&ts->low_latency_req,
193						DEV_PM_QOS_RESUME_LATENCY, 100);
194	}
195
196out:
197	return IRQ_HANDLED;
198}
199
200static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron)
201{
202	if (ts->reset_gpio)
203		gpiod_set_value_cansleep(ts->reset_gpio, !poweron);
204}
205
206static void st1232_ts_power_off(void *data)
207{
208	st1232_ts_power(data, false);
209}
210
211static const struct st_chip_info st1232_chip_info = {
212	.have_z		= true,
213	.max_area	= 0xff,
214	.max_fingers	= 2,
215};
216
217static const struct st_chip_info st1633_chip_info = {
218	.have_z		= false,
219	.max_area	= 0x00,
220	.max_fingers	= 5,
221};
222
223static int st1232_ts_probe(struct i2c_client *client)
224{
225	const struct i2c_device_id *id = i2c_client_get_device_id(client);
226	const struct st_chip_info *match;
227	struct st1232_ts_data *ts;
228	struct input_dev *input_dev;
229	u16 max_x, max_y;
230	int error;
231
232	match = device_get_match_data(&client->dev);
233	if (!match && id)
234		match = (const void *)id->driver_data;
235	if (!match) {
236		dev_err(&client->dev, "unknown device model\n");
237		return -ENODEV;
238	}
239
240	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
241		dev_err(&client->dev, "need I2C_FUNC_I2C\n");
242		return -EIO;
243	}
244
245	if (!client->irq) {
246		dev_err(&client->dev, "no IRQ?\n");
247		return -EINVAL;
248	}
249
250	ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
251	if (!ts)
252		return -ENOMEM;
253
254	ts->chip_info = match;
255
256	/* allocate a buffer according to the number of registers to read */
257	ts->read_buf_len = ts->chip_info->max_fingers * 4;
258	ts->read_buf = devm_kzalloc(&client->dev, ts->read_buf_len, GFP_KERNEL);
259	if (!ts->read_buf)
260		return -ENOMEM;
261
262	input_dev = devm_input_allocate_device(&client->dev);
263	if (!input_dev)
264		return -ENOMEM;
265
266	ts->client = client;
267	ts->input_dev = input_dev;
268
269	ts->reset_gpio = devm_gpiod_get_optional(&client->dev, NULL,
270						 GPIOD_OUT_HIGH);
271	if (IS_ERR(ts->reset_gpio)) {
272		error = PTR_ERR(ts->reset_gpio);
273		dev_err(&client->dev, "Unable to request GPIO pin: %d.\n",
274			error);
275		return error;
276	}
277
278	st1232_ts_power(ts, true);
279
280	error = devm_add_action_or_reset(&client->dev, st1232_ts_power_off, ts);
281	if (error) {
282		dev_err(&client->dev,
283			"Failed to install power off action: %d\n", error);
284		return error;
285	}
286
287	input_dev->name = "st1232-touchscreen";
288	input_dev->id.bustype = BUS_I2C;
289
290	/* Wait until device is ready */
291	error = st1232_ts_wait_ready(ts);
292	if (error)
293		return error;
294
295	/* Read resolution from the chip */
296	error = st1232_ts_read_resolution(ts, &max_x, &max_y);
297	if (error) {
298		dev_err(&client->dev,
299			"Failed to read resolution: %d\n", error);
300		return error;
301	}
302
303	if (ts->chip_info->have_z)
304		input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
305				     ts->chip_info->max_area, 0, 0);
306
307	input_set_abs_params(input_dev, ABS_MT_POSITION_X,
308			     0, max_x, 0, 0);
309	input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
310			     0, max_y, 0, 0);
311
312	touchscreen_parse_properties(input_dev, true, &ts->prop);
313
314	error = input_mt_init_slots(input_dev, ts->chip_info->max_fingers,
315				    INPUT_MT_DIRECT | INPUT_MT_TRACK |
316					INPUT_MT_DROP_UNUSED);
317	if (error) {
318		dev_err(&client->dev, "failed to initialize MT slots\n");
319		return error;
320	}
321
322	error = devm_request_threaded_irq(&client->dev, client->irq,
323					  NULL, st1232_ts_irq_handler,
324					  IRQF_ONESHOT,
325					  client->name, ts);
326	if (error) {
327		dev_err(&client->dev, "Failed to register interrupt\n");
328		return error;
329	}
330
331	error = input_register_device(ts->input_dev);
332	if (error) {
333		dev_err(&client->dev, "Unable to register %s input device\n",
334			input_dev->name);
335		return error;
336	}
337
338	i2c_set_clientdata(client, ts);
339
340	return 0;
341}
342
343static int st1232_ts_suspend(struct device *dev)
344{
345	struct i2c_client *client = to_i2c_client(dev);
346	struct st1232_ts_data *ts = i2c_get_clientdata(client);
347
348	disable_irq(client->irq);
349
350	if (!device_may_wakeup(&client->dev))
351		st1232_ts_power(ts, false);
352
353	return 0;
354}
355
356static int st1232_ts_resume(struct device *dev)
357{
358	struct i2c_client *client = to_i2c_client(dev);
359	struct st1232_ts_data *ts = i2c_get_clientdata(client);
360
361	if (!device_may_wakeup(&client->dev))
362		st1232_ts_power(ts, true);
363
364	enable_irq(client->irq);
365
366	return 0;
367}
368
369static DEFINE_SIMPLE_DEV_PM_OPS(st1232_ts_pm_ops,
370				st1232_ts_suspend, st1232_ts_resume);
371
372static const struct i2c_device_id st1232_ts_id[] = {
373	{ ST1232_TS_NAME, (unsigned long)&st1232_chip_info },
374	{ ST1633_TS_NAME, (unsigned long)&st1633_chip_info },
375	{ }
376};
377MODULE_DEVICE_TABLE(i2c, st1232_ts_id);
378
379static const struct of_device_id st1232_ts_dt_ids[] = {
380	{ .compatible = "sitronix,st1232", .data = &st1232_chip_info },
381	{ .compatible = "sitronix,st1633", .data = &st1633_chip_info },
382	{ }
383};
384MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids);
385
386static struct i2c_driver st1232_ts_driver = {
387	.probe		= st1232_ts_probe,
388	.id_table	= st1232_ts_id,
389	.driver = {
390		.name	= ST1232_TS_NAME,
391		.of_match_table = st1232_ts_dt_ids,
392		.probe_type	= PROBE_PREFER_ASYNCHRONOUS,
393		.pm	= pm_sleep_ptr(&st1232_ts_pm_ops),
394	},
395};
396
397module_i2c_driver(st1232_ts_driver);
398
399MODULE_AUTHOR("Tony SIM <chinyeow.sim.xt@renesas.com>");
400MODULE_AUTHOR("Martin Kepplinger <martin.kepplinger@ginzinger.com>");
401MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver");
402MODULE_LICENSE("GPL v2");
403