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
28 struct st1232_ts_finger {
29 u16 x;
30 u16 y;
31 u8 t;
32 bool is_valid;
33 };
34
35 struct 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
44 struct 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
st1232_ts_read_data(struct st1232_ts_data * ts)56 static 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) |
85 buf[i + y + 1];
86 finger[i].y = ((buf[i + y] & 0x0007) << 8) |
87 buf[i + y + 2];
88
89 /* st1232 includes a z-axis / touch strength */
90 if (ts->chip_info->have_z)
91 finger[i].t = buf[i + 6];
92 }
93 }
94
95 return 0;
96 }
97
st1232_ts_irq_handler(int irq,void * dev_id)98 static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
99 {
100 struct st1232_ts_data *ts = dev_id;
101 struct st1232_ts_finger *finger = ts->finger;
102 struct input_dev *input_dev = ts->input_dev;
103 int count = 0;
104 int i, ret;
105
106 ret = st1232_ts_read_data(ts);
107 if (ret < 0)
108 goto end;
109
110 /* multi touch protocol */
111 for (i = 0; i < ts->chip_info->max_fingers; i++) {
112 if (!finger[i].is_valid)
113 continue;
114
115 if (ts->chip_info->have_z)
116 input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR,
117 finger[i].t);
118
119 touchscreen_report_pos(input_dev, &ts->prop,
120 finger[i].x, finger[i].y, true);
121 input_mt_sync(input_dev);
122 count++;
123 }
124
125 /* SYN_MT_REPORT only if no contact */
126 if (!count) {
127 input_mt_sync(input_dev);
128 if (ts->low_latency_req.dev) {
129 dev_pm_qos_remove_request(&ts->low_latency_req);
130 ts->low_latency_req.dev = NULL;
131 }
132 } else if (!ts->low_latency_req.dev) {
133 /* First contact, request 100 us latency. */
134 dev_pm_qos_add_ancestor_request(&ts->client->dev,
135 &ts->low_latency_req,
136 DEV_PM_QOS_RESUME_LATENCY, 100);
137 }
138
139 /* SYN_REPORT */
140 input_sync(input_dev);
141
142 end:
143 return IRQ_HANDLED;
144 }
145
st1232_ts_power(struct st1232_ts_data * ts,bool poweron)146 static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron)
147 {
148 if (ts->reset_gpio)
149 gpiod_set_value_cansleep(ts->reset_gpio, !poweron);
150 }
151
st1232_ts_power_off(void * data)152 static void st1232_ts_power_off(void *data)
153 {
154 st1232_ts_power(data, false);
155 }
156
157 static const struct st_chip_info st1232_chip_info = {
158 .have_z = true,
159 .max_x = 0x31f, /* 800 - 1 */
160 .max_y = 0x1df, /* 480 -1 */
161 .max_area = 0xff,
162 .max_fingers = 2,
163 .start_reg = 0x12,
164 };
165
166 static const struct st_chip_info st1633_chip_info = {
167 .have_z = false,
168 .max_x = 0x13f, /* 320 - 1 */
169 .max_y = 0x1df, /* 480 -1 */
170 .max_area = 0x00,
171 .max_fingers = 5,
172 .start_reg = 0x12,
173 };
174
st1232_ts_probe(struct i2c_client * client,const struct i2c_device_id * id)175 static int st1232_ts_probe(struct i2c_client *client,
176 const struct i2c_device_id *id)
177 {
178 const struct st_chip_info *match;
179 struct st1232_ts_data *ts;
180 struct st1232_ts_finger *finger;
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 ts->finger = devm_kcalloc(&client->dev,
208 ts->chip_info->max_fingers, sizeof(*finger),
209 GFP_KERNEL);
210 if (!ts->finger)
211 return -ENOMEM;
212
213 /* allocate a buffer according to the number of registers to read */
214 ts->read_buf_len = ts->chip_info->max_fingers * 4;
215 ts->read_buf = devm_kzalloc(&client->dev, ts->read_buf_len, GFP_KERNEL);
216 if (!ts->read_buf)
217 return -ENOMEM;
218
219 input_dev = devm_input_allocate_device(&client->dev);
220 if (!input_dev)
221 return -ENOMEM;
222
223 ts->client = client;
224 ts->input_dev = input_dev;
225
226 ts->reset_gpio = devm_gpiod_get_optional(&client->dev, NULL,
227 GPIOD_OUT_HIGH);
228 if (IS_ERR(ts->reset_gpio)) {
229 error = PTR_ERR(ts->reset_gpio);
230 dev_err(&client->dev, "Unable to request GPIO pin: %d.\n",
231 error);
232 return error;
233 }
234
235 st1232_ts_power(ts, true);
236
237 error = devm_add_action_or_reset(&client->dev, st1232_ts_power_off, ts);
238 if (error) {
239 dev_err(&client->dev,
240 "Failed to install power off action: %d\n", error);
241 return error;
242 }
243
244 input_dev->name = "st1232-touchscreen";
245 input_dev->id.bustype = BUS_I2C;
246 input_dev->dev.parent = &client->dev;
247
248 __set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
249 __set_bit(EV_SYN, input_dev->evbit);
250 __set_bit(EV_KEY, input_dev->evbit);
251 __set_bit(EV_ABS, input_dev->evbit);
252
253 if (ts->chip_info->have_z)
254 input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
255 ts->chip_info->max_area, 0, 0);
256
257 input_set_abs_params(input_dev, ABS_MT_POSITION_X,
258 0, ts->chip_info->max_x, 0, 0);
259 input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
260 0, ts->chip_info->max_y, 0, 0);
261
262 touchscreen_parse_properties(input_dev, true, &ts->prop);
263
264 error = devm_request_threaded_irq(&client->dev, client->irq,
265 NULL, st1232_ts_irq_handler,
266 IRQF_ONESHOT,
267 client->name, ts);
268 if (error) {
269 dev_err(&client->dev, "Failed to register interrupt\n");
270 return error;
271 }
272
273 error = input_register_device(ts->input_dev);
274 if (error) {
275 dev_err(&client->dev, "Unable to register %s input device\n",
276 input_dev->name);
277 return error;
278 }
279
280 i2c_set_clientdata(client, ts);
281 device_init_wakeup(&client->dev, 1);
282
283 return 0;
284 }
285
st1232_ts_suspend(struct device * dev)286 static int __maybe_unused st1232_ts_suspend(struct device *dev)
287 {
288 struct i2c_client *client = to_i2c_client(dev);
289 struct st1232_ts_data *ts = i2c_get_clientdata(client);
290
291 if (device_may_wakeup(&client->dev)) {
292 enable_irq_wake(client->irq);
293 } else {
294 disable_irq(client->irq);
295 st1232_ts_power(ts, false);
296 }
297
298 return 0;
299 }
300
st1232_ts_resume(struct device * dev)301 static int __maybe_unused st1232_ts_resume(struct device *dev)
302 {
303 struct i2c_client *client = to_i2c_client(dev);
304 struct st1232_ts_data *ts = i2c_get_clientdata(client);
305
306 if (device_may_wakeup(&client->dev)) {
307 disable_irq_wake(client->irq);
308 } else {
309 st1232_ts_power(ts, true);
310 enable_irq(client->irq);
311 }
312
313 return 0;
314 }
315
316 static SIMPLE_DEV_PM_OPS(st1232_ts_pm_ops,
317 st1232_ts_suspend, st1232_ts_resume);
318
319 static const struct i2c_device_id st1232_ts_id[] = {
320 { ST1232_TS_NAME, (unsigned long)&st1232_chip_info },
321 { ST1633_TS_NAME, (unsigned long)&st1633_chip_info },
322 { }
323 };
324 MODULE_DEVICE_TABLE(i2c, st1232_ts_id);
325
326 static const struct of_device_id st1232_ts_dt_ids[] = {
327 { .compatible = "sitronix,st1232", .data = &st1232_chip_info },
328 { .compatible = "sitronix,st1633", .data = &st1633_chip_info },
329 { }
330 };
331 MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids);
332
333 static struct i2c_driver st1232_ts_driver = {
334 .probe = st1232_ts_probe,
335 .id_table = st1232_ts_id,
336 .driver = {
337 .name = ST1232_TS_NAME,
338 .of_match_table = st1232_ts_dt_ids,
339 .pm = &st1232_ts_pm_ops,
340 },
341 };
342
343 module_i2c_driver(st1232_ts_driver);
344
345 MODULE_AUTHOR("Tony SIM <chinyeow.sim.xt@renesas.com>");
346 MODULE_AUTHOR("Martin Kepplinger <martin.kepplinger@ginzinger.com>");
347 MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver");
348 MODULE_LICENSE("GPL v2");
349