blob: 80467f262331e2c94ae9686f21e473b4d203f3f5 [file] [log] [blame]
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -05001/*
2 * drivers/input/touchscreen/tsc2007.c
3 *
4 * Copyright (c) 2008 MtekVision Co., Ltd.
5 * Kwangwoo Lee <kwlee@mtekvision.com>
6 *
7 * Using code from:
8 * - ads7846.c
9 * Copyright (c) 2005 David Brownell
10 * Copyright (c) 2006 Nokia Corporation
11 * - corgi_ts.c
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
17 *
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.
21 */
22
23#include <linux/module.h>
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -050024#include <linux/slab.h>
25#include <linux/input.h>
26#include <linux/interrupt.h>
27#include <linux/i2c.h>
28#include <linux/i2c/tsc2007.h>
29
Dmitry Torokhov141586bc2009-07-24 23:14:16 -070030#define TS_POLL_DELAY 1 /* ms delay between samples */
31#define TS_POLL_PERIOD 1 /* ms delay between samples */
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -050032
33#define TSC2007_MEASURE_TEMP0 (0x0 << 4)
34#define TSC2007_MEASURE_AUX (0x2 << 4)
35#define TSC2007_MEASURE_TEMP1 (0x4 << 4)
36#define TSC2007_ACTIVATE_XN (0x8 << 4)
37#define TSC2007_ACTIVATE_YN (0x9 << 4)
38#define TSC2007_ACTIVATE_YP_XN (0xa << 4)
39#define TSC2007_SETUP (0xb << 4)
40#define TSC2007_MEASURE_X (0xc << 4)
41#define TSC2007_MEASURE_Y (0xd << 4)
42#define TSC2007_MEASURE_Z1 (0xe << 4)
43#define TSC2007_MEASURE_Z2 (0xf << 4)
44
45#define TSC2007_POWER_OFF_IRQ_EN (0x0 << 2)
46#define TSC2007_ADC_ON_IRQ_DIS0 (0x1 << 2)
47#define TSC2007_ADC_OFF_IRQ_EN (0x2 << 2)
48#define TSC2007_ADC_ON_IRQ_DIS1 (0x3 << 2)
49
50#define TSC2007_12BIT (0x0 << 1)
51#define TSC2007_8BIT (0x1 << 1)
52
53#define MAX_12BIT ((1 << 12) - 1)
54
55#define ADC_ON_12BIT (TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
56
57#define READ_Y (ADC_ON_12BIT | TSC2007_MEASURE_Y)
58#define READ_Z1 (ADC_ON_12BIT | TSC2007_MEASURE_Z1)
59#define READ_Z2 (ADC_ON_12BIT | TSC2007_MEASURE_Z2)
60#define READ_X (ADC_ON_12BIT | TSC2007_MEASURE_X)
61#define PWRDOWN (TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
62
63struct ts_event {
64 u16 x;
65 u16 y;
66 u16 z1, z2;
67};
68
69struct tsc2007 {
70 struct input_dev *input;
71 char phys[32];
Richard Röjfors75fba3b2009-07-24 22:01:39 -070072 struct delayed_work work;
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -050073
74 struct i2c_client *client;
75
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -050076 u16 model;
77 u16 x_plate_ohms;
78
Dmitry Torokhov141586bc2009-07-24 23:14:16 -070079 bool pendown;
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -050080 int irq;
81
82 int (*get_pendown_state)(void);
83 void (*clear_penirq)(void);
84};
85
86static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
87{
88 s32 data;
89 u16 val;
90
91 data = i2c_smbus_read_word_data(tsc->client, cmd);
92 if (data < 0) {
93 dev_err(&tsc->client->dev, "i2c io error: %d\n", data);
94 return data;
95 }
96
97 /* The protocol and raw data format from i2c interface:
98 * S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P
99 * Where DataLow has [D11-D4], DataHigh has [D3-D0 << 4 | Dummy 4bit].
100 */
101 val = swab16(data) >> 4;
102
103 dev_dbg(&tsc->client->dev, "data: 0x%x, val: 0x%x\n", data, val);
104
105 return val;
106}
107
Dmitry Torokhovd570e9e2009-08-04 22:07:26 -0700108static void tsc2007_read_values(struct tsc2007 *tsc, struct ts_event *tc)
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500109{
Dmitry Torokhovd570e9e2009-08-04 22:07:26 -0700110 /* y- still on; turn on only y+ (and ADC) */
111 tc->y = tsc2007_xfer(tsc, READ_Y);
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500112
Dmitry Torokhovd570e9e2009-08-04 22:07:26 -0700113 /* turn y- off, x+ on, then leave in lowpower */
114 tc->x = tsc2007_xfer(tsc, READ_X);
115
116 /* turn y+ off, x- on; we'll use formula #1 */
117 tc->z1 = tsc2007_xfer(tsc, READ_Z1);
118 tc->z2 = tsc2007_xfer(tsc, READ_Z2);
119
120 /* Prepare for next touch reading - power down ADC, enable PENIRQ */
121 tsc2007_xfer(tsc, PWRDOWN);
122}
123
124static u32 tsc2007_calculate_pressure(struct tsc2007 *tsc, struct ts_event *tc)
125{
126 u32 rt = 0;
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500127
128 /* range filtering */
Dmitry Torokhovd570e9e2009-08-04 22:07:26 -0700129 if (tc->x == MAX_12BIT)
130 tc->x = 0;
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500131
Dmitry Torokhovd570e9e2009-08-04 22:07:26 -0700132 if (likely(tc->x && tc->z1)) {
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500133 /* compute touch pressure resistance using equation #1 */
Dmitry Torokhovd570e9e2009-08-04 22:07:26 -0700134 rt = tc->z2 - tc->z1;
135 rt *= tc->x;
136 rt *= tsc->x_plate_ohms;
137 rt /= tc->z1;
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500138 rt = (rt + 2047) >> 12;
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500139 }
140
Dmitry Torokhovd570e9e2009-08-04 22:07:26 -0700141 return rt;
142}
143
144static void tsc2007_send_up_event(struct tsc2007 *tsc)
145{
146 struct input_dev *input = tsc->input;
147
148 dev_dbg(&tsc->client->dev, "UP\n");
149
150 input_report_key(input, BTN_TOUCH, 0);
151 input_report_abs(input, ABS_PRESSURE, 0);
152 input_sync(input);
153}
154
155static void tsc2007_work(struct work_struct *work)
156{
157 struct tsc2007 *ts =
158 container_of(to_delayed_work(work), struct tsc2007, work);
159 struct ts_event tc;
160 u32 rt;
161
Dmitry Torokhov141586bc2009-07-24 23:14:16 -0700162 /*
163 * NOTE: We can't rely on the pressure to determine the pen down
Dmitry Torokhovd570e9e2009-08-04 22:07:26 -0700164 * state, even though this controller has a pressure sensor.
165 * The pressure value can fluctuate for quite a while after
166 * lifting the pen and in some cases may not even settle at the
167 * expected value.
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500168 *
169 * The only safe way to check for the pen up condition is in the
Dmitry Torokhovd570e9e2009-08-04 22:07:26 -0700170 * work function by reading the pen signal state (it's a GPIO
171 * and IRQ). Unfortunately such callback is not always available,
172 * in that case we have rely on the pressure anyway.
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500173 */
Dmitry Torokhovd570e9e2009-08-04 22:07:26 -0700174 if (ts->get_pendown_state) {
175 if (unlikely(!ts->get_pendown_state())) {
176 tsc2007_send_up_event(ts);
177 ts->pendown = false;
178 goto out;
179 }
180
181 dev_dbg(&ts->client->dev, "pen is still down\n");
182 }
183
184 tsc2007_read_values(ts, &tc);
185
186 rt = tsc2007_calculate_pressure(ts, &tc);
187 if (rt > MAX_12BIT) {
188 /*
189 * Sample found inconsistent by debouncing or pressure is
190 * beyond the maximum. Don't report it to user space,
191 * repeat at least once more the measurement.
192 */
193 dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);
194 goto out;
195
196 }
197
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500198 if (rt) {
199 struct input_dev *input = ts->input;
200
201 if (!ts->pendown) {
202 dev_dbg(&ts->client->dev, "DOWN\n");
203
204 input_report_key(input, BTN_TOUCH, 1);
Dmitry Torokhov141586bc2009-07-24 23:14:16 -0700205 ts->pendown = true;
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500206 }
207
Dmitry Torokhovd570e9e2009-08-04 22:07:26 -0700208 input_report_abs(input, ABS_X, tc.x);
209 input_report_abs(input, ABS_Y, tc.y);
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500210 input_report_abs(input, ABS_PRESSURE, rt);
211
212 input_sync(input);
213
214 dev_dbg(&ts->client->dev, "point(%4d,%4d), pressure (%4u)\n",
Dmitry Torokhovd570e9e2009-08-04 22:07:26 -0700215 tc.x, tc.y, rt);
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500216
Dmitry Torokhovd570e9e2009-08-04 22:07:26 -0700217 } else if (!ts->get_pendown_state && ts->pendown) {
218 /*
219 * We don't have callback to check pendown state, so we
220 * have to assume that since pressure reported is 0 the
221 * pen was lifted up.
222 */
223 tsc2007_send_up_event(ts);
Dmitry Torokhov141586bc2009-07-24 23:14:16 -0700224 ts->pendown = false;
Dmitry Torokhovd570e9e2009-08-04 22:07:26 -0700225 }
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500226
Dmitry Torokhovd570e9e2009-08-04 22:07:26 -0700227 out:
228 if (ts->pendown)
Dmitry Torokhov141586bc2009-07-24 23:14:16 -0700229 schedule_delayed_work(&ts->work,
230 msecs_to_jiffies(TS_POLL_PERIOD));
Dmitry Torokhovd570e9e2009-08-04 22:07:26 -0700231 else
232 enable_irq(ts->irq);
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500233}
234
235static irqreturn_t tsc2007_irq(int irq, void *handle)
236{
237 struct tsc2007 *ts = handle;
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500238
Dmitry Torokhovd570e9e2009-08-04 22:07:26 -0700239 if (!ts->get_pendown_state || likely(ts->get_pendown_state())) {
Ben Nizette29fa98b2009-04-17 20:35:57 -0700240 disable_irq_nosync(ts->irq);
Dmitry Torokhov141586bc2009-07-24 23:14:16 -0700241 schedule_delayed_work(&ts->work,
242 msecs_to_jiffies(TS_POLL_DELAY));
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500243 }
244
245 if (ts->clear_penirq)
246 ts->clear_penirq();
247
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500248 return IRQ_HANDLED;
249}
250
Dmitry Torokhov141586bc2009-07-24 23:14:16 -0700251static void tsc2007_free_irq(struct tsc2007 *ts)
252{
253 free_irq(ts->irq, ts);
254 if (cancel_delayed_work_sync(&ts->work)) {
255 /*
256 * Work was pending, therefore we need to enable
257 * IRQ here to balance the disable_irq() done in the
258 * interrupt handler.
259 */
260 enable_irq(ts->irq);
261 }
262}
263
264static int __devinit tsc2007_probe(struct i2c_client *client,
265 const struct i2c_device_id *id)
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500266{
267 struct tsc2007 *ts;
Axel Linb496acb2010-09-02 19:52:41 -0700268 struct tsc2007_platform_data *pdata = client->dev.platform_data;
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500269 struct input_dev *input_dev;
270 int err;
271
Dmitry Torokhovd570e9e2009-08-04 22:07:26 -0700272 if (!pdata) {
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500273 dev_err(&client->dev, "platform data is required!\n");
274 return -EINVAL;
275 }
276
277 if (!i2c_check_functionality(client->adapter,
278 I2C_FUNC_SMBUS_READ_WORD_DATA))
279 return -EIO;
280
281 ts = kzalloc(sizeof(struct tsc2007), GFP_KERNEL);
282 input_dev = input_allocate_device();
283 if (!ts || !input_dev) {
284 err = -ENOMEM;
285 goto err_free_mem;
286 }
287
288 ts->client = client;
Dmitry Torokhov141586bc2009-07-24 23:14:16 -0700289 ts->irq = client->irq;
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500290 ts->input = input_dev;
Dmitry Torokhov141586bc2009-07-24 23:14:16 -0700291 INIT_DELAYED_WORK(&ts->work, tsc2007_work);
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500292
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500293 ts->model = pdata->model;
294 ts->x_plate_ohms = pdata->x_plate_ohms;
295 ts->get_pendown_state = pdata->get_pendown_state;
296 ts->clear_penirq = pdata->clear_penirq;
297
Kay Sievers4e8718a2009-01-29 22:56:08 -0800298 snprintf(ts->phys, sizeof(ts->phys),
299 "%s/input0", dev_name(&client->dev));
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500300
301 input_dev->name = "TSC2007 Touchscreen";
302 input_dev->phys = ts->phys;
303 input_dev->id.bustype = BUS_I2C;
304
305 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
306 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
307
308 input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
309 input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
310 input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);
311
Richard Röjforscad065f2009-07-24 23:14:17 -0700312 if (pdata->init_platform_hw)
313 pdata->init_platform_hw();
Richard Röjfors75fba3b2009-07-24 22:01:39 -0700314
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500315 err = request_irq(ts->irq, tsc2007_irq, 0,
316 client->dev.driver->name, ts);
317 if (err < 0) {
318 dev_err(&client->dev, "irq %d busy?\n", ts->irq);
319 goto err_free_mem;
320 }
321
Richard Röjforscf5f4392009-08-04 22:34:10 -0700322 /* Prepare for touch readings - power down ADC and enable PENIRQ */
323 err = tsc2007_xfer(ts, PWRDOWN);
324 if (err < 0)
325 goto err_free_irq;
326
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500327 err = input_register_device(input_dev);
328 if (err)
329 goto err_free_irq;
330
Dmitry Torokhov141586bc2009-07-24 23:14:16 -0700331 i2c_set_clientdata(client, ts);
332
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500333 return 0;
334
335 err_free_irq:
Dmitry Torokhov141586bc2009-07-24 23:14:16 -0700336 tsc2007_free_irq(ts);
Richard Röjforscad065f2009-07-24 23:14:17 -0700337 if (pdata->exit_platform_hw)
338 pdata->exit_platform_hw();
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500339 err_free_mem:
340 input_free_device(input_dev);
341 kfree(ts);
342 return err;
343}
344
Dmitry Torokhov141586bc2009-07-24 23:14:16 -0700345static int __devexit tsc2007_remove(struct i2c_client *client)
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500346{
347 struct tsc2007 *ts = i2c_get_clientdata(client);
Dmitry Torokhov141586bc2009-07-24 23:14:16 -0700348 struct tsc2007_platform_data *pdata = client->dev.platform_data;
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500349
Dmitry Torokhov141586bc2009-07-24 23:14:16 -0700350 tsc2007_free_irq(ts);
Richard Röjfors75fba3b2009-07-24 22:01:39 -0700351
Richard Röjforscad065f2009-07-24 23:14:17 -0700352 if (pdata->exit_platform_hw)
353 pdata->exit_platform_hw();
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500354
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500355 input_unregister_device(ts->input);
356 kfree(ts);
357
358 return 0;
359}
360
Márton Némethce7b39a2010-01-09 23:23:02 -0800361static const struct i2c_device_id tsc2007_idtable[] = {
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500362 { "tsc2007", 0 },
363 { }
364};
365
366MODULE_DEVICE_TABLE(i2c, tsc2007_idtable);
367
368static struct i2c_driver tsc2007_driver = {
369 .driver = {
370 .owner = THIS_MODULE,
371 .name = "tsc2007"
372 },
373 .id_table = tsc2007_idtable,
374 .probe = tsc2007_probe,
Dmitry Torokhov141586bc2009-07-24 23:14:16 -0700375 .remove = __devexit_p(tsc2007_remove),
Kwangwoo Lee50b6f1f2008-12-20 04:26:01 -0500376};
377
378static int __init tsc2007_init(void)
379{
380 return i2c_add_driver(&tsc2007_driver);
381}
382
383static void __exit tsc2007_exit(void)
384{
385 i2c_del_driver(&tsc2007_driver);
386}
387
388module_init(tsc2007_init);
389module_exit(tsc2007_exit);
390
391MODULE_AUTHOR("Kwangwoo Lee <kwlee@mtekvision.com>");
392MODULE_DESCRIPTION("TSC2007 TouchScreen Driver");
393MODULE_LICENSE("GPL");