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#include <linux/input/touch-overlay.h>
 26
 27#define ST1232_TS_NAME	"st1232-ts"
 28#define ST1633_TS_NAME	"st1633-ts"
 29
 30#define REG_STATUS		0x01	/* Device Status | Error Code */
 31
 32#define STATUS_NORMAL		0x00
 33#define STATUS_INIT		0x01
 34#define STATUS_ERROR		0x02
 35#define STATUS_AUTO_TUNING	0x03
 36#define STATUS_IDLE		0x04
 37#define STATUS_POWER_DOWN	0x05
 38
 39#define ERROR_NONE		0x00
 40#define ERROR_INVALID_ADDRESS	0x10
 41#define ERROR_INVALID_VALUE	0x20
 42#define ERROR_INVALID_PLATFORM	0x30
 43
 44#define REG_XY_RESOLUTION	0x04
 45#define REG_XY_COORDINATES	0x12
 46#define ST_TS_MAX_FINGERS	10
 47
 48struct st_chip_info {
 49	bool	have_z;
 50	u16	max_area;
 51	u16	max_fingers;
 52};
 53
 54struct st1232_ts_data {
 55	struct i2c_client *client;
 56	struct input_dev *input_dev;
 57	struct touchscreen_properties prop;
 58	struct dev_pm_qos_request low_latency_req;
 59	struct gpio_desc *reset_gpio;
 60	const struct st_chip_info *chip_info;
 61	struct list_head touch_overlay_list;
 62	int read_buf_len;
 63	u8 *read_buf;
 64};
 65
 66static int st1232_ts_read_data(struct st1232_ts_data *ts, u8 reg,
 67			       unsigned int n)
 68{
 69	struct i2c_client *client = ts->client;
 70	struct i2c_msg msg[] = {
 71		{
 72			.addr	= client->addr,
 73			.len	= sizeof(reg),
 74			.buf	= &reg,
 75		},
 76		{
 77			.addr	= client->addr,
 78			.flags	= I2C_M_RD | I2C_M_DMA_SAFE,
 79			.len	= n,
 80			.buf	= ts->read_buf,
 81		}
 82	};
 83	int ret;
 84
 85	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
 86	if (ret != ARRAY_SIZE(msg))
 87		return ret < 0 ? ret : -EIO;
 88
 89	return 0;
 90}
 91
 92static int st1232_ts_wait_ready(struct st1232_ts_data *ts)
 93{
 94	unsigned int retries;
 95	int error;
 96
 97	for (retries = 100; retries; retries--) {
 98		error = st1232_ts_read_data(ts, REG_STATUS, 1);
 99		if (!error) {
100			switch (ts->read_buf[0]) {
101			case STATUS_NORMAL | ERROR_NONE:
102			case STATUS_IDLE | ERROR_NONE:
103				return 0;
104			}
105		}
106
107		usleep_range(1000, 2000);
108	}
109
110	return -ENXIO;
111}
112
113static int st1232_ts_read_resolution(struct st1232_ts_data *ts, u16 *max_x,
114				     u16 *max_y)
115{
116	u8 *buf;
117	int error;
118
119	/* select resolution register */
120	error = st1232_ts_read_data(ts, REG_XY_RESOLUTION, 3);
121	if (error)
122		return error;
123
124	buf = ts->read_buf;
125
126	*max_x = (((buf[0] & 0x0070) << 4) | buf[1]) - 1;
127	*max_y = (((buf[0] & 0x0007) << 8) | buf[2]) - 1;
128
129	return 0;
130}
131
132static int st1232_ts_parse_and_report(struct st1232_ts_data *ts)
133{
134	struct input_dev *input = ts->input_dev;
135	struct input_mt_pos pos[ST_TS_MAX_FINGERS];
136	u8 z[ST_TS_MAX_FINGERS];
137	int slots[ST_TS_MAX_FINGERS];
138	int n_contacts = 0;
139	int i;
140
141	for (i = 0; i < ts->chip_info->max_fingers; i++) {
142		u8 *buf = &ts->read_buf[i * 4];
143
144		if (buf[0] & BIT(7)) {
145			unsigned int x = ((buf[0] & 0x70) << 4) | buf[1];
146			unsigned int y = ((buf[0] & 0x07) << 8) | buf[2];
147
148			touchscreen_set_mt_pos(&pos[n_contacts],
149					       &ts->prop, x, y);
150
151			/* st1232 includes a z-axis / touch strength */
152			if (ts->chip_info->have_z)
153				z[n_contacts] = ts->read_buf[i + 6];
154
155			n_contacts++;
156		}
157	}
158
159	input_mt_assign_slots(input, slots, pos, n_contacts, 0);
160	for (i = 0; i < n_contacts; i++) {
161		if (touch_overlay_process_contact(&ts->touch_overlay_list,
162						  input, &pos[i], slots[i]))
163			continue;
164
165		input_mt_slot(input, slots[i]);
166		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
167		input_report_abs(input, ABS_MT_POSITION_X, pos[i].x);
168		input_report_abs(input, ABS_MT_POSITION_Y, pos[i].y);
169		if (ts->chip_info->have_z)
170			input_report_abs(input, ABS_MT_TOUCH_MAJOR, z[i]);
171	}
172
173	touch_overlay_sync_frame(&ts->touch_overlay_list, input);
174	input_mt_sync_frame(input);
175	input_sync(input);
176
177	return n_contacts;
178}
179
180static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
181{
182	struct st1232_ts_data *ts = dev_id;
183	int count;
184	int error;
185
186	error = st1232_ts_read_data(ts, REG_XY_COORDINATES, ts->read_buf_len);
187	if (error)
188		goto out;
189
190	count = st1232_ts_parse_and_report(ts);
191	if (!count) {
192		if (ts->low_latency_req.dev) {
193			dev_pm_qos_remove_request(&ts->low_latency_req);
194			ts->low_latency_req.dev = NULL;
195		}
196	} else if (!ts->low_latency_req.dev) {
197		/* First contact, request 100 us latency. */
198		dev_pm_qos_add_ancestor_request(&ts->client->dev,
199						&ts->low_latency_req,
200						DEV_PM_QOS_RESUME_LATENCY, 100);
201	}
202
203out:
204	return IRQ_HANDLED;
205}
206
207static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron)
208{
209	if (ts->reset_gpio)
210		gpiod_set_value_cansleep(ts->reset_gpio, !poweron);
211}
212
213static void st1232_ts_power_off(void *data)
214{
215	st1232_ts_power(data, false);
216}
217
218static const struct st_chip_info st1232_chip_info = {
219	.have_z		= true,
220	.max_area	= 0xff,
221	.max_fingers	= 2,
222};
223
224static const struct st_chip_info st1633_chip_info = {
225	.have_z		= false,
226	.max_area	= 0x00,
227	.max_fingers	= 5,
228};
229
230static int st1232_ts_probe(struct i2c_client *client)
231{
232	const struct i2c_device_id *id = i2c_client_get_device_id(client);
233	const struct st_chip_info *match;
234	struct st1232_ts_data *ts;
235	struct input_dev *input_dev;
236	u16 max_x, max_y;
237	int error;
238
239	match = device_get_match_data(&client->dev);
240	if (!match && id)
241		match = (const void *)id->driver_data;
242	if (!match) {
243		dev_err(&client->dev, "unknown device model\n");
244		return -ENODEV;
245	}
246
247	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
248		dev_err(&client->dev, "need I2C_FUNC_I2C\n");
249		return -EIO;
250	}
251
252	if (!client->irq) {
253		dev_err(&client->dev, "no IRQ?\n");
254		return -EINVAL;
255	}
256
257	ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
258	if (!ts)
259		return -ENOMEM;
260
261	ts->chip_info = match;
262
263	/* allocate a buffer according to the number of registers to read */
264	ts->read_buf_len = ts->chip_info->max_fingers * 4;
265	ts->read_buf = devm_kzalloc(&client->dev, ts->read_buf_len, GFP_KERNEL);
266	if (!ts->read_buf)
267		return -ENOMEM;
268
269	input_dev = devm_input_allocate_device(&client->dev);
270	if (!input_dev)
271		return -ENOMEM;
272
273	ts->client = client;
274	ts->input_dev = input_dev;
275
276	ts->reset_gpio = devm_gpiod_get_optional(&client->dev, NULL,
277						 GPIOD_OUT_HIGH);
278	if (IS_ERR(ts->reset_gpio)) {
279		error = PTR_ERR(ts->reset_gpio);
280		dev_err(&client->dev, "Unable to request GPIO pin: %d.\n",
281			error);
282		return error;
283	}
284
285	st1232_ts_power(ts, true);
286
287	error = devm_add_action_or_reset(&client->dev, st1232_ts_power_off, ts);
288	if (error) {
289		dev_err(&client->dev,
290			"Failed to install power off action: %d\n", error);
291		return error;
292	}
293
294	input_dev->name = "st1232-touchscreen";
295	input_dev->id.bustype = BUS_I2C;
296
297	/* Wait until device is ready */
298	error = st1232_ts_wait_ready(ts);
299	if (error)
300		return error;
301
302	if (ts->chip_info->have_z)
303		input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
304				     ts->chip_info->max_area, 0, 0);
305
306	/* map overlay objects if defined in the device tree */
307	INIT_LIST_HEAD(&ts->touch_overlay_list);
308	error = touch_overlay_map(&ts->touch_overlay_list, input_dev);
309	if (error)
310		return error;
311
312	if (touch_overlay_mapped_touchscreen(&ts->touch_overlay_list)) {
313		/* Read resolution from the overlay touchscreen if defined */
314		touch_overlay_get_touchscreen_abs(&ts->touch_overlay_list,
315						  &max_x, &max_y);
316	} else {
317		/* Read resolution from the chip */
318		error = st1232_ts_read_resolution(ts, &max_x, &max_y);
319		if (error) {
320			dev_err(&client->dev,
321				"Failed to read resolution: %d\n", error);
322			return error;
323		}
324	}
325
326	input_set_abs_params(input_dev, ABS_MT_POSITION_X,
327			     0, max_x, 0, 0);
328	input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
329			     0, max_y, 0, 0);
330
331	touchscreen_parse_properties(input_dev, true, &ts->prop);
332
333	error = input_mt_init_slots(input_dev, ts->chip_info->max_fingers,
334				    INPUT_MT_DIRECT | INPUT_MT_TRACK |
335					INPUT_MT_DROP_UNUSED);
336	if (error) {
337		dev_err(&client->dev, "failed to initialize MT slots\n");
338		return error;
339	}
340
341	error = devm_request_threaded_irq(&client->dev, client->irq,
342					  NULL, st1232_ts_irq_handler,
343					  IRQF_ONESHOT,
344					  client->name, ts);
345	if (error) {
346		dev_err(&client->dev, "Failed to register interrupt\n");
347		return error;
348	}
349
350	error = input_register_device(ts->input_dev);
351	if (error) {
352		dev_err(&client->dev, "Unable to register %s input device\n",
353			input_dev->name);
354		return error;
355	}
356
357	i2c_set_clientdata(client, ts);
358
359	return 0;
360}
361
362static int st1232_ts_suspend(struct device *dev)
363{
364	struct i2c_client *client = to_i2c_client(dev);
365	struct st1232_ts_data *ts = i2c_get_clientdata(client);
366
367	disable_irq(client->irq);
368
369	if (!device_may_wakeup(&client->dev))
370		st1232_ts_power(ts, false);
371
372	return 0;
373}
374
375static int st1232_ts_resume(struct device *dev)
376{
377	struct i2c_client *client = to_i2c_client(dev);
378	struct st1232_ts_data *ts = i2c_get_clientdata(client);
379
380	if (!device_may_wakeup(&client->dev))
381		st1232_ts_power(ts, true);
382
383	enable_irq(client->irq);
384
385	return 0;
386}
387
388static DEFINE_SIMPLE_DEV_PM_OPS(st1232_ts_pm_ops,
389				st1232_ts_suspend, st1232_ts_resume);
390
391static const struct i2c_device_id st1232_ts_id[] = {
392	{ ST1232_TS_NAME, (unsigned long)&st1232_chip_info },
393	{ ST1633_TS_NAME, (unsigned long)&st1633_chip_info },
394	{ }
395};
396MODULE_DEVICE_TABLE(i2c, st1232_ts_id);
397
398static const struct of_device_id st1232_ts_dt_ids[] = {
399	{ .compatible = "sitronix,st1232", .data = &st1232_chip_info },
400	{ .compatible = "sitronix,st1633", .data = &st1633_chip_info },
401	{ }
402};
403MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids);
404
405static struct i2c_driver st1232_ts_driver = {
406	.probe		= st1232_ts_probe,
407	.id_table	= st1232_ts_id,
408	.driver = {
409		.name	= ST1232_TS_NAME,
410		.of_match_table = st1232_ts_dt_ids,
411		.probe_type	= PROBE_PREFER_ASYNCHRONOUS,
412		.pm	= pm_sleep_ptr(&st1232_ts_pm_ops),
413	},
414};
415
416module_i2c_driver(st1232_ts_driver);
417
418MODULE_AUTHOR("Tony SIM <chinyeow.sim.xt@renesas.com>");
419MODULE_AUTHOR("Martin Kepplinger <martin.kepplinger@ginzinger.com>");
420MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver");
421MODULE_LICENSE("GPL v2");