2 * drivers/input/touchscreen/tsc2007.c
4 * Copyright (c) 2008 MtekVision Co., Ltd.
5 * Kwangwoo Lee <kwlee@mtekvision.com>
9 * Copyright (c) 2005 David Brownell
10 * Copyright (c) 2006 Nokia Corporation
12 * Copyright (C) 2004-2005 Richard Purdie
13 * - omap_ts.[hc], ads7846.h, ts_osk.c
14 * Copyright (C) 2002 MontaVista Software
15 * Copyright (C) 2004 Texas Instruments
16 * Copyright (C) 2005 Dirk Behme
18 * This program is free software; you can redistribute it and/or modify
19 * it under the terms of the GNU General Public License version 2 as
20 * published by the Free Software Foundation.
23 #include <linux/module.h>
24 #include <linux/hrtimer.h>
25 #include <linux/slab.h>
26 #include <linux/input.h>
27 #include <linux/interrupt.h>
28 #include <linux/i2c.h>
29 #include <linux/i2c/tsc2007.h>
31 #define TS_POLL_DELAY (10 * 1000) /* ns delay before the first sample */
32 #define TS_POLL_PERIOD (5 * 1000) /* ns delay between samples */
34 #define TSC2007_MEASURE_TEMP0 (0x0 << 4)
35 #define TSC2007_MEASURE_AUX (0x2 << 4)
36 #define TSC2007_MEASURE_TEMP1 (0x4 << 4)
37 #define TSC2007_ACTIVATE_XN (0x8 << 4)
38 #define TSC2007_ACTIVATE_YN (0x9 << 4)
39 #define TSC2007_ACTIVATE_YP_XN (0xa << 4)
40 #define TSC2007_SETUP (0xb << 4)
41 #define TSC2007_MEASURE_X (0xc << 4)
42 #define TSC2007_MEASURE_Y (0xd << 4)
43 #define TSC2007_MEASURE_Z1 (0xe << 4)
44 #define TSC2007_MEASURE_Z2 (0xf << 4)
46 #define TSC2007_POWER_OFF_IRQ_EN (0x0 << 2)
47 #define TSC2007_ADC_ON_IRQ_DIS0 (0x1 << 2)
48 #define TSC2007_ADC_OFF_IRQ_EN (0x2 << 2)
49 #define TSC2007_ADC_ON_IRQ_DIS1 (0x3 << 2)
51 #define TSC2007_12BIT (0x0 << 1)
52 #define TSC2007_8BIT (0x1 << 1)
54 #define MAX_12BIT ((1 << 12) - 1)
56 #define ADC_ON_12BIT (TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
58 #define READ_Y (ADC_ON_12BIT | TSC2007_MEASURE_Y)
59 #define READ_Z1 (ADC_ON_12BIT | TSC2007_MEASURE_Z1)
60 #define READ_Z2 (ADC_ON_12BIT | TSC2007_MEASURE_Z2)
61 #define READ_X (ADC_ON_12BIT | TSC2007_MEASURE_X)
62 #define PWRDOWN (TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
71 struct input_dev *input;
76 struct i2c_client *client;
86 int (*get_pendown_state)(void);
87 void (*clear_penirq)(void);
90 static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
95 data = i2c_smbus_read_word_data(tsc->client, cmd);
97 dev_err(&tsc->client->dev, "i2c io error: %d\n", data);
101 /* The protocol and raw data format from i2c interface:
102 * S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P
103 * Where DataLow has [D11-D4], DataHigh has [D3-D0 << 4 | Dummy 4bit].
105 val = swab16(data) >> 4;
107 dev_dbg(&tsc->client->dev, "data: 0x%x, val: 0x%x\n", data, val);
112 static void tsc2007_send_event(void *tsc)
114 struct tsc2007 *ts = tsc;
123 /* range filtering */
127 if (likely(x && z1)) {
128 /* compute touch pressure resistance using equation #1 */
132 rt *= ts->x_plate_ohms;
134 rt = (rt + 2047) >> 12;
138 /* Sample found inconsistent by debouncing or pressure is beyond
139 * the maximum. Don't report it to user space, repeat at least
140 * once more the measurement
142 if (rt > MAX_12BIT) {
143 dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);
145 hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
150 /* NOTE: We can't rely on the pressure to determine the pen down
151 * state, even this controller has a pressure sensor. The pressure
152 * value can fluctuate for quite a while after lifting the pen and
153 * in some cases may not even settle at the expected value.
155 * The only safe way to check for the pen up condition is in the
156 * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
159 struct input_dev *input = ts->input;
162 dev_dbg(&ts->client->dev, "DOWN\n");
164 input_report_key(input, BTN_TOUCH, 1);
168 input_report_abs(input, ABS_X, x);
169 input_report_abs(input, ABS_Y, y);
170 input_report_abs(input, ABS_PRESSURE, rt);
174 dev_dbg(&ts->client->dev, "point(%4d,%4d), pressure (%4u)\n",
178 hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
182 static int tsc2007_read_values(struct tsc2007 *tsc)
184 /* y- still on; turn on only y+ (and ADC) */
185 tsc->tc.y = tsc2007_xfer(tsc, READ_Y);
187 /* turn y- off, x+ on, then leave in lowpower */
188 tsc->tc.x = tsc2007_xfer(tsc, READ_X);
190 /* turn y+ off, x- on; we'll use formula #1 */
191 tsc->tc.z1 = tsc2007_xfer(tsc, READ_Z1);
192 tsc->tc.z2 = tsc2007_xfer(tsc, READ_Z2);
195 tsc2007_xfer(tsc, PWRDOWN);
200 static enum hrtimer_restart tsc2007_timer(struct hrtimer *handle)
202 struct tsc2007 *ts = container_of(handle, struct tsc2007, timer);
205 spin_lock_irqsave(&ts->lock, flags);
207 if (unlikely(!ts->get_pendown_state() && ts->pendown)) {
208 struct input_dev *input = ts->input;
210 dev_dbg(&ts->client->dev, "UP\n");
212 input_report_key(input, BTN_TOUCH, 0);
213 input_report_abs(input, ABS_PRESSURE, 0);
219 /* pen is still down, continue with the measurement */
220 dev_dbg(&ts->client->dev, "pen is still down\n");
222 tsc2007_read_values(ts);
223 tsc2007_send_event(ts);
226 spin_unlock_irqrestore(&ts->lock, flags);
228 return HRTIMER_NORESTART;
231 static irqreturn_t tsc2007_irq(int irq, void *handle)
233 struct tsc2007 *ts = handle;
236 spin_lock_irqsave(&ts->lock, flags);
238 if (likely(ts->get_pendown_state())) {
239 disable_irq_nosync(ts->irq);
240 hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_DELAY),
244 if (ts->clear_penirq)
247 spin_unlock_irqrestore(&ts->lock, flags);
252 static int tsc2007_probe(struct i2c_client *client,
253 const struct i2c_device_id *id)
256 struct tsc2007_platform_data *pdata = pdata = client->dev.platform_data;
257 struct input_dev *input_dev;
261 dev_err(&client->dev, "platform data is required!\n");
265 if (!i2c_check_functionality(client->adapter,
266 I2C_FUNC_SMBUS_READ_WORD_DATA))
269 ts = kzalloc(sizeof(struct tsc2007), GFP_KERNEL);
270 input_dev = input_allocate_device();
271 if (!ts || !input_dev) {
277 i2c_set_clientdata(client, ts);
279 ts->input = input_dev;
281 hrtimer_init(&ts->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
282 ts->timer.function = tsc2007_timer;
284 spin_lock_init(&ts->lock);
286 ts->model = pdata->model;
287 ts->x_plate_ohms = pdata->x_plate_ohms;
288 ts->get_pendown_state = pdata->get_pendown_state;
289 ts->clear_penirq = pdata->clear_penirq;
291 pdata->init_platform_hw();
293 snprintf(ts->phys, sizeof(ts->phys),
294 "%s/input0", dev_name(&client->dev));
296 input_dev->name = "TSC2007 Touchscreen";
297 input_dev->phys = ts->phys;
298 input_dev->id.bustype = BUS_I2C;
300 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
301 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
303 input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
304 input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
305 input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);
307 tsc2007_read_values(ts);
309 ts->irq = client->irq;
311 err = request_irq(ts->irq, tsc2007_irq, 0,
312 client->dev.driver->name, ts);
314 dev_err(&client->dev, "irq %d busy?\n", ts->irq);
318 err = input_register_device(input_dev);
322 dev_info(&client->dev, "registered with irq (%d)\n", ts->irq);
327 free_irq(ts->irq, ts);
328 hrtimer_cancel(&ts->timer);
330 input_free_device(input_dev);
335 static int tsc2007_remove(struct i2c_client *client)
337 struct tsc2007 *ts = i2c_get_clientdata(client);
338 struct tsc2007_platform_data *pdata;
340 pdata = client->dev.platform_data;
341 pdata->exit_platform_hw();
343 free_irq(ts->irq, ts);
344 hrtimer_cancel(&ts->timer);
345 input_unregister_device(ts->input);
351 static struct i2c_device_id tsc2007_idtable[] = {
356 MODULE_DEVICE_TABLE(i2c, tsc2007_idtable);
358 static struct i2c_driver tsc2007_driver = {
360 .owner = THIS_MODULE,
363 .id_table = tsc2007_idtable,
364 .probe = tsc2007_probe,
365 .remove = tsc2007_remove,
368 static int __init tsc2007_init(void)
370 return i2c_add_driver(&tsc2007_driver);
373 static void __exit tsc2007_exit(void)
375 i2c_del_driver(&tsc2007_driver);
378 module_init(tsc2007_init);
379 module_exit(tsc2007_exit);
381 MODULE_AUTHOR("Kwangwoo Lee <kwlee@mtekvision.com>");
382 MODULE_DESCRIPTION("TSC2007 TouchScreen Driver");
383 MODULE_LICENSE("GPL");