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/interrupt.h>
18#include <linux/module.h>
19#include <linux/of.h>
20#include <linux/pm_qos.h>
21#include <linux/slab.h>
22#include <linux/types.h>
23#include <linux/input/touchscreen.h>
24
25#define ST1232_TS_NAME "st1232-ts"
26#define ST1633_TS_NAME "st1633-ts"
27
28struct st1232_ts_finger {
29 u16 x;
30 u16 y;
31 u8 t;
32 bool is_valid;
33};
34
35struct st_chip_info {
36 bool have_z;
37 u16 max_x;
38 u16 max_y;
39 u16 max_area;
40 u16 max_fingers;
41 u8 start_reg;
42};
43
44struct st1232_ts_data {
45 struct i2c_client *client;
46 struct input_dev *input_dev;
47 struct touchscreen_properties prop;
48 struct dev_pm_qos_request low_latency_req;
49 struct gpio_desc *reset_gpio;
50 const struct st_chip_info *chip_info;
51 int read_buf_len;
52 u8 *read_buf;
53 struct st1232_ts_finger *finger;
54};
55
56static int st1232_ts_read_data(struct st1232_ts_data *ts)
57{
58 struct st1232_ts_finger *finger = ts->finger;
59 struct i2c_client *client = ts->client;
60 struct i2c_msg msg[2];
61 int error;
62 int i, y;
63 u8 start_reg = ts->chip_info->start_reg;
64 u8 *buf = ts->read_buf;
65
66 /* read touchscreen data */
67 msg[0].addr = client->addr;
68 msg[0].flags = 0;
69 msg[0].len = 1;
70 msg[0].buf = &start_reg;
71
72 msg[1].addr = ts->client->addr;
73 msg[1].flags = I2C_M_RD;
74 msg[1].len = ts->read_buf_len;
75 msg[1].buf = buf;
76
77 error = i2c_transfer(client->adapter, msg, 2);
78 if (error < 0)
79 return error;
80
81 for (i = 0, y = 0; i < ts->chip_info->max_fingers; i++, y += 3) {
82 finger[i].is_valid = buf[i + y] >> 7;
83 if (finger[i].is_valid) {
84 finger[i].x = ((buf[i + y] & 0x0070) << 4) | buf[i + 1];
85 finger[i].y = ((buf[i + y] & 0x0007) << 8) | buf[i + 2];
86
87 /* st1232 includes a z-axis / touch strength */
88 if (ts->chip_info->have_z)
89 finger[i].t = buf[i + 6];
90 }
91 }
92
93 return 0;
94}
95
96static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
97{
98 struct st1232_ts_data *ts = dev_id;
99 struct st1232_ts_finger *finger = ts->finger;
100 struct input_dev *input_dev = ts->input_dev;
101 int count = 0;
102 int i, ret;
103
104 ret = st1232_ts_read_data(ts);
105 if (ret < 0)
106 goto end;
107
108 /* multi touch protocol */
109 for (i = 0; i < ts->chip_info->max_fingers; i++) {
110 if (!finger[i].is_valid)
111 continue;
112
113 if (ts->chip_info->have_z)
114 input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR,
115 finger[i].t);
116
117 touchscreen_report_pos(input_dev, &ts->prop,
118 finger[i].x, finger[i].y, true);
119 input_mt_sync(input_dev);
120 count++;
121 }
122
123 /* SYN_MT_REPORT only if no contact */
124 if (!count) {
125 input_mt_sync(input_dev);
126 if (ts->low_latency_req.dev) {
127 dev_pm_qos_remove_request(&ts->low_latency_req);
128 ts->low_latency_req.dev = NULL;
129 }
130 } else if (!ts->low_latency_req.dev) {
131 /* First contact, request 100 us latency. */
132 dev_pm_qos_add_ancestor_request(&ts->client->dev,
133 &ts->low_latency_req,
134 DEV_PM_QOS_RESUME_LATENCY, 100);
135 }
136
137 /* SYN_REPORT */
138 input_sync(input_dev);
139
140end:
141 return IRQ_HANDLED;
142}
143
144static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron)
145{
146 if (ts->reset_gpio)
147 gpiod_set_value_cansleep(ts->reset_gpio, !poweron);
148}
149
150static const struct st_chip_info st1232_chip_info = {
151 .have_z = true,
152 .max_x = 0x31f, /* 800 - 1 */
153 .max_y = 0x1df, /* 480 -1 */
154 .max_area = 0xff,
155 .max_fingers = 2,
156 .start_reg = 0x12,
157};
158
159static const struct st_chip_info st1633_chip_info = {
160 .have_z = false,
161 .max_x = 0x13f, /* 320 - 1 */
162 .max_y = 0x1df, /* 480 -1 */
163 .max_area = 0x00,
164 .max_fingers = 5,
165 .start_reg = 0x12,
166};
167
168static int st1232_ts_probe(struct i2c_client *client,
169 const struct i2c_device_id *id)
170{
171 const struct st_chip_info *match;
172 struct st1232_ts_data *ts;
173 struct st1232_ts_finger *finger;
174 struct input_dev *input_dev;
175 int error;
176
177 match = device_get_match_data(&client->dev);
178 if (!match && id)
179 match = (const void *)id->driver_data;
180 if (!match) {
181 dev_err(&client->dev, "unknown device model\n");
182 return -ENODEV;
183 }
184
185 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
186 dev_err(&client->dev, "need I2C_FUNC_I2C\n");
187 return -EIO;
188 }
189
190 if (!client->irq) {
191 dev_err(&client->dev, "no IRQ?\n");
192 return -EINVAL;
193 }
194
195 ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
196 if (!ts)
197 return -ENOMEM;
198
199 ts->chip_info = match;
200 ts->finger = devm_kcalloc(&client->dev,
201 ts->chip_info->max_fingers, sizeof(*finger),
202 GFP_KERNEL);
203 if (!ts->finger)
204 return -ENOMEM;
205
206 /* allocate a buffer according to the number of registers to read */
207 ts->read_buf_len = ts->chip_info->max_fingers * 4;
208 ts->read_buf = devm_kzalloc(&client->dev, ts->read_buf_len, GFP_KERNEL);
209 if (!ts->read_buf)
210 return -ENOMEM;
211
212 input_dev = devm_input_allocate_device(&client->dev);
213 if (!input_dev)
214 return -ENOMEM;
215
216 ts->client = client;
217 ts->input_dev = input_dev;
218
219 ts->reset_gpio = devm_gpiod_get_optional(&client->dev, NULL,
220 GPIOD_OUT_HIGH);
221 if (IS_ERR(ts->reset_gpio)) {
222 error = PTR_ERR(ts->reset_gpio);
223 dev_err(&client->dev, "Unable to request GPIO pin: %d.\n",
224 error);
225 return error;
226 }
227
228 st1232_ts_power(ts, true);
229
230 input_dev->name = "st1232-touchscreen";
231 input_dev->id.bustype = BUS_I2C;
232 input_dev->dev.parent = &client->dev;
233
234 __set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
235 __set_bit(EV_SYN, input_dev->evbit);
236 __set_bit(EV_KEY, input_dev->evbit);
237 __set_bit(EV_ABS, input_dev->evbit);
238
239 if (ts->chip_info->have_z)
240 input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
241 ts->chip_info->max_area, 0, 0);
242
243 input_set_abs_params(input_dev, ABS_MT_POSITION_X,
244 0, ts->chip_info->max_x, 0, 0);
245 input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
246 0, ts->chip_info->max_y, 0, 0);
247
248 touchscreen_parse_properties(input_dev, true, &ts->prop);
249
250 error = devm_request_threaded_irq(&client->dev, client->irq,
251 NULL, st1232_ts_irq_handler,
252 IRQF_ONESHOT,
253 client->name, ts);
254 if (error) {
255 dev_err(&client->dev, "Failed to register interrupt\n");
256 return error;
257 }
258
259 error = input_register_device(ts->input_dev);
260 if (error) {
261 dev_err(&client->dev, "Unable to register %s input device\n",
262 input_dev->name);
263 return error;
264 }
265
266 i2c_set_clientdata(client, ts);
267 device_init_wakeup(&client->dev, 1);
268
269 return 0;
270}
271
272static int st1232_ts_remove(struct i2c_client *client)
273{
274 struct st1232_ts_data *ts = i2c_get_clientdata(client);
275
276 st1232_ts_power(ts, false);
277
278 return 0;
279}
280
281static int __maybe_unused st1232_ts_suspend(struct device *dev)
282{
283 struct i2c_client *client = to_i2c_client(dev);
284 struct st1232_ts_data *ts = i2c_get_clientdata(client);
285
286 if (device_may_wakeup(&client->dev)) {
287 enable_irq_wake(client->irq);
288 } else {
289 disable_irq(client->irq);
290 st1232_ts_power(ts, false);
291 }
292
293 return 0;
294}
295
296static int __maybe_unused st1232_ts_resume(struct device *dev)
297{
298 struct i2c_client *client = to_i2c_client(dev);
299 struct st1232_ts_data *ts = i2c_get_clientdata(client);
300
301 if (device_may_wakeup(&client->dev)) {
302 disable_irq_wake(client->irq);
303 } else {
304 st1232_ts_power(ts, true);
305 enable_irq(client->irq);
306 }
307
308 return 0;
309}
310
311static SIMPLE_DEV_PM_OPS(st1232_ts_pm_ops,
312 st1232_ts_suspend, st1232_ts_resume);
313
314static const struct i2c_device_id st1232_ts_id[] = {
315 { ST1232_TS_NAME, (unsigned long)&st1232_chip_info },
316 { ST1633_TS_NAME, (unsigned long)&st1633_chip_info },
317 { }
318};
319MODULE_DEVICE_TABLE(i2c, st1232_ts_id);
320
321static const struct of_device_id st1232_ts_dt_ids[] = {
322 { .compatible = "sitronix,st1232", .data = &st1232_chip_info },
323 { .compatible = "sitronix,st1633", .data = &st1633_chip_info },
324 { }
325};
326MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids);
327
328static struct i2c_driver st1232_ts_driver = {
329 .probe = st1232_ts_probe,
330 .remove = st1232_ts_remove,
331 .id_table = st1232_ts_id,
332 .driver = {
333 .name = ST1232_TS_NAME,
334 .of_match_table = st1232_ts_dt_ids,
335 .pm = &st1232_ts_pm_ops,
336 },
337};
338
339module_i2c_driver(st1232_ts_driver);
340
341MODULE_AUTHOR("Tony SIM <chinyeow.sim.xt@renesas.com>");
342MODULE_AUTHOR("Martin Kepplinger <martin.kepplinger@ginzinger.com>");
343MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver");
344MODULE_LICENSE("GPL v2");
345