1 // SPDX-License-Identifier: GPL-2.0-only
3 * drivers/input/touchscreen/tsc2007.c
5 * Copyright (c) 2008 MtekVision Co., Ltd.
6 * Kwangwoo Lee <kwlee@mtekvision.com>
10 * Copyright (c) 2005 David Brownell
11 * Copyright (c) 2006 Nokia Corporation
13 * Copyright (C) 2004-2005 Richard Purdie
14 * - omap_ts.[hc], ads7846.h, ts_osk.c
15 * Copyright (C) 2002 MontaVista Software
16 * Copyright (C) 2004 Texas Instruments
17 * Copyright (C) 2005 Dirk Behme
20 #include <linux/module.h>
21 #include <linux/slab.h>
22 #include <linux/gpio/consumer.h>
23 #include <linux/input.h>
24 #include <linux/interrupt.h>
25 #include <linux/i2c.h>
26 #include <linux/mod_devicetable.h>
27 #include <linux/property.h>
28 #include <linux/platform_data/tsc2007.h>
31 int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
36 data = i2c_smbus_read_word_data(tsc->client, cmd);
38 dev_err(&tsc->client->dev, "i2c io error: %d\n", data);
42 /* The protocol and raw data format from i2c interface:
43 * S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P
44 * Where DataLow has [D11-D4], DataHigh has [D3-D0 << 4 | Dummy 4bit].
46 val = swab16(data) >> 4;
48 dev_dbg(&tsc->client->dev, "data: 0x%x, val: 0x%x\n", data, val);
53 static void tsc2007_read_values(struct tsc2007 *tsc, struct ts_event *tc)
55 /* y- still on; turn on only y+ (and ADC) */
56 tc->y = tsc2007_xfer(tsc, READ_Y);
58 /* turn y- off, x+ on, then leave in lowpower */
59 tc->x = tsc2007_xfer(tsc, READ_X);
61 /* turn y+ off, x- on; we'll use formula #1 */
62 tc->z1 = tsc2007_xfer(tsc, READ_Z1);
63 tc->z2 = tsc2007_xfer(tsc, READ_Z2);
65 /* Prepare for next touch reading - power down ADC, enable PENIRQ */
66 tsc2007_xfer(tsc, PWRDOWN);
69 u32 tsc2007_calculate_resistance(struct tsc2007 *tsc, struct ts_event *tc)
74 if (tc->x == MAX_12BIT)
77 if (likely(tc->x && tc->z1)) {
78 /* compute touch resistance using equation #1 */
81 rt *= tsc->x_plate_ohms;
83 rt = (rt + 2047) >> 12;
89 bool tsc2007_is_pen_down(struct tsc2007 *ts)
92 * NOTE: We can't rely on the pressure to determine the pen down
93 * state, even though this controller has a pressure sensor.
94 * The pressure value can fluctuate for quite a while after
95 * lifting the pen and in some cases may not even settle at the
98 * The only safe way to check for the pen up condition is in the
99 * work function by reading the pen signal state (it's a GPIO
100 * and IRQ). Unfortunately such callback is not always available,
101 * in that case we assume that the pen is down and expect caller
102 * to fall back on the pressure reading.
105 if (!ts->get_pendown_state)
108 return ts->get_pendown_state(&ts->client->dev);
111 static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
113 struct tsc2007 *ts = handle;
114 struct input_dev *input = ts->input;
118 while (!ts->stopped && tsc2007_is_pen_down(ts)) {
120 /* pen is down, continue with the measurement */
122 mutex_lock(&ts->mlock);
123 tsc2007_read_values(ts, &tc);
124 mutex_unlock(&ts->mlock);
126 rt = tsc2007_calculate_resistance(ts, &tc);
128 if (!rt && !ts->get_pendown_state) {
130 * If pressure reported is 0 and we don't have
131 * callback to check pendown state, we have to
132 * assume that pen was lifted up.
137 if (rt <= ts->max_rt) {
138 dev_dbg(&ts->client->dev,
139 "DOWN point(%4d,%4d), resistance (%4u)\n",
142 rt = ts->max_rt - rt;
144 input_report_key(input, BTN_TOUCH, 1);
145 input_report_abs(input, ABS_X, tc.x);
146 input_report_abs(input, ABS_Y, tc.y);
147 input_report_abs(input, ABS_PRESSURE, rt);
153 * Sample found inconsistent by debouncing or pressure is
154 * beyond the maximum. Don't report it to user space,
155 * repeat at least once more the measurement.
157 dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);
160 wait_event_timeout(ts->wait, ts->stopped, ts->poll_period);
163 dev_dbg(&ts->client->dev, "UP\n");
165 input_report_key(input, BTN_TOUCH, 0);
166 input_report_abs(input, ABS_PRESSURE, 0);
169 if (ts->clear_penirq)
175 static irqreturn_t tsc2007_hard_irq(int irq, void *handle)
177 struct tsc2007 *ts = handle;
179 if (tsc2007_is_pen_down(ts))
180 return IRQ_WAKE_THREAD;
182 if (ts->clear_penirq)
188 static void tsc2007_stop(struct tsc2007 *ts)
194 disable_irq(ts->irq);
197 static int tsc2007_open(struct input_dev *input_dev)
199 struct tsc2007 *ts = input_get_drvdata(input_dev);
207 /* Prepare for touch readings - power down ADC and enable PENIRQ */
208 err = tsc2007_xfer(ts, PWRDOWN);
217 static void tsc2007_close(struct input_dev *input_dev)
219 struct tsc2007 *ts = input_get_drvdata(input_dev);
224 static int tsc2007_get_pendown_state_gpio(struct device *dev)
226 struct i2c_client *client = to_i2c_client(dev);
227 struct tsc2007 *ts = i2c_get_clientdata(client);
229 return gpiod_get_value(ts->gpiod);
232 static int tsc2007_probe_properties(struct device *dev, struct tsc2007 *ts)
237 if (!device_property_read_u32(dev, "ti,max-rt", &val32))
240 ts->max_rt = MAX_12BIT;
242 if (!device_property_read_u32(dev, "ti,fuzzx", &val32))
245 if (!device_property_read_u32(dev, "ti,fuzzy", &val32))
248 if (!device_property_read_u32(dev, "ti,fuzzz", &val32))
251 if (!device_property_read_u64(dev, "ti,poll-period", &val64))
252 ts->poll_period = msecs_to_jiffies(val64);
254 ts->poll_period = msecs_to_jiffies(1);
256 if (!device_property_read_u32(dev, "ti,x-plate-ohms", &val32)) {
257 ts->x_plate_ohms = val32;
259 dev_err(dev, "Missing ti,x-plate-ohms device property\n");
263 ts->gpiod = devm_gpiod_get_optional(dev, NULL, GPIOD_IN);
264 if (IS_ERR(ts->gpiod))
265 return PTR_ERR(ts->gpiod);
268 ts->get_pendown_state = tsc2007_get_pendown_state_gpio;
270 dev_warn(dev, "Pen down GPIO is not specified in properties\n");
275 static int tsc2007_probe_pdev(struct device *dev, struct tsc2007 *ts,
276 const struct tsc2007_platform_data *pdata,
277 const struct i2c_device_id *id)
279 ts->model = pdata->model;
280 ts->x_plate_ohms = pdata->x_plate_ohms;
281 ts->max_rt = pdata->max_rt ? : MAX_12BIT;
282 ts->poll_period = msecs_to_jiffies(pdata->poll_period ? : 1);
283 ts->get_pendown_state = pdata->get_pendown_state;
284 ts->clear_penirq = pdata->clear_penirq;
285 ts->fuzzx = pdata->fuzzx;
286 ts->fuzzy = pdata->fuzzy;
287 ts->fuzzz = pdata->fuzzz;
289 if (pdata->x_plate_ohms == 0) {
290 dev_err(dev, "x_plate_ohms is not set up in platform data\n");
297 static void tsc2007_call_exit_platform_hw(void *data)
299 struct device *dev = data;
300 const struct tsc2007_platform_data *pdata = dev_get_platdata(dev);
302 pdata->exit_platform_hw();
305 static int tsc2007_probe(struct i2c_client *client,
306 const struct i2c_device_id *id)
308 const struct tsc2007_platform_data *pdata =
309 dev_get_platdata(&client->dev);
311 struct input_dev *input_dev;
314 if (!i2c_check_functionality(client->adapter,
315 I2C_FUNC_SMBUS_READ_WORD_DATA))
318 ts = devm_kzalloc(&client->dev, sizeof(struct tsc2007), GFP_KERNEL);
323 err = tsc2007_probe_pdev(&client->dev, ts, pdata, id);
325 err = tsc2007_probe_properties(&client->dev, ts);
329 input_dev = devm_input_allocate_device(&client->dev);
333 i2c_set_clientdata(client, ts);
336 ts->irq = client->irq;
337 ts->input = input_dev;
339 init_waitqueue_head(&ts->wait);
340 mutex_init(&ts->mlock);
342 snprintf(ts->phys, sizeof(ts->phys),
343 "%s/input0", dev_name(&client->dev));
345 input_dev->name = "TSC2007 Touchscreen";
346 input_dev->phys = ts->phys;
347 input_dev->id.bustype = BUS_I2C;
349 input_dev->open = tsc2007_open;
350 input_dev->close = tsc2007_close;
352 input_set_drvdata(input_dev, ts);
354 input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
356 input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, ts->fuzzx, 0);
357 input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, ts->fuzzy, 0);
358 input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT,
362 if (pdata->exit_platform_hw) {
363 err = devm_add_action(&client->dev,
364 tsc2007_call_exit_platform_hw,
367 dev_err(&client->dev,
368 "Failed to register exit_platform_hw action, %d\n",
374 if (pdata->init_platform_hw)
375 pdata->init_platform_hw();
378 err = devm_request_threaded_irq(&client->dev, ts->irq,
379 tsc2007_hard_irq, tsc2007_soft_irq,
381 client->dev.driver->name, ts);
383 dev_err(&client->dev, "Failed to request irq %d: %d\n",
390 /* power down the chip (TSC2007_SETUP does not ACK on I2C) */
391 err = tsc2007_xfer(ts, PWRDOWN);
393 dev_err(&client->dev,
394 "Failed to setup chip: %d\n", err);
395 return err; /* chip does not respond */
398 err = input_register_device(input_dev);
400 dev_err(&client->dev,
401 "Failed to register input device: %d\n", err);
405 err = tsc2007_iio_configure(ts);
407 dev_err(&client->dev,
408 "Failed to register with IIO: %d\n", err);
415 static const struct i2c_device_id tsc2007_idtable[] = {
420 MODULE_DEVICE_TABLE(i2c, tsc2007_idtable);
422 static const struct of_device_id tsc2007_of_match[] = {
423 { .compatible = "ti,tsc2007" },
426 MODULE_DEVICE_TABLE(of, tsc2007_of_match);
428 static struct i2c_driver tsc2007_driver = {
431 .of_match_table = tsc2007_of_match,
433 .id_table = tsc2007_idtable,
434 .probe = tsc2007_probe,
437 module_i2c_driver(tsc2007_driver);
439 MODULE_AUTHOR("Kwangwoo Lee <kwlee@mtekvision.com>");
440 MODULE_DESCRIPTION("TSC2007 TouchScreen Driver");
441 MODULE_LICENSE("GPL");