Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 | /*
* drivers/input/touchscreen/tsc2007.c
*
* Copyright (c) 2008 MtekVision Co., Ltd.
* Kwangwoo Lee <kwlee@mtekvision.com>
*
* Using code from:
* - ads7846.c
* Copyright (c) 2005 David Brownell
* Copyright (c) 2006 Nokia Corporation
* - corgi_ts.c
* Copyright (C) 2004-2005 Richard Purdie
* - omap_ts.[hc], ads7846.h, ts_osk.c
* Copyright (C) 2002 MontaVista Software
* Copyright (C) 2004 Texas Instruments
* Copyright (C) 2005 Dirk Behme
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/i2c/tsc2007.h>
#define TSC2007_MEASURE_TEMP0 (0x0 << 4)
#define TSC2007_MEASURE_AUX (0x2 << 4)
#define TSC2007_MEASURE_TEMP1 (0x4 << 4)
#define TSC2007_ACTIVATE_XN (0x8 << 4)
#define TSC2007_ACTIVATE_YN (0x9 << 4)
#define TSC2007_ACTIVATE_YP_XN (0xa << 4)
#define TSC2007_SETUP (0xb << 4)
#define TSC2007_MEASURE_X (0xc << 4)
#define TSC2007_MEASURE_Y (0xd << 4)
#define TSC2007_MEASURE_Z1 (0xe << 4)
#define TSC2007_MEASURE_Z2 (0xf << 4)
#define TSC2007_POWER_OFF_IRQ_EN (0x0 << 2)
#define TSC2007_ADC_ON_IRQ_DIS0 (0x1 << 2)
#define TSC2007_ADC_OFF_IRQ_EN (0x2 << 2)
#define TSC2007_ADC_ON_IRQ_DIS1 (0x3 << 2)
#define TSC2007_12BIT (0x0 << 1)
#define TSC2007_8BIT (0x1 << 1)
#define MAX_12BIT ((1 << 12) - 1)
#define ADC_ON_12BIT (TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
#define READ_Y (ADC_ON_12BIT | TSC2007_MEASURE_Y)
#define READ_Z1 (ADC_ON_12BIT | TSC2007_MEASURE_Z1)
#define READ_Z2 (ADC_ON_12BIT | TSC2007_MEASURE_Z2)
#define READ_X (ADC_ON_12BIT | TSC2007_MEASURE_X)
#define PWRDOWN (TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
struct ts_event {
u16 x;
u16 y;
u16 z1, z2;
};
struct tsc2007 {
struct input_dev *input;
char phys[32];
struct delayed_work work;
struct i2c_client *client;
u16 model;
u16 x_plate_ohms;
u16 max_rt;
unsigned long poll_delay;
unsigned long poll_period;
bool pendown;
int irq;
int (*get_pendown_state)(void);
void (*clear_penirq)(void);
};
static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
{
s32 data;
u16 val;
data = i2c_smbus_read_word_data(tsc->client, cmd);
if (data < 0) {
dev_err(&tsc->client->dev, "i2c io error: %d\n", data);
return data;
}
/* The protocol and raw data format from i2c interface:
* S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P
* Where DataLow has [D11-D4], DataHigh has [D3-D0 << 4 | Dummy 4bit].
*/
val = swab16(data) >> 4;
dev_dbg(&tsc->client->dev, "data: 0x%x, val: 0x%x\n", data, val);
return val;
}
static void tsc2007_read_values(struct tsc2007 *tsc, struct ts_event *tc)
{
/* y- still on; turn on only y+ (and ADC) */
tc->y = tsc2007_xfer(tsc, READ_Y);
/* turn y- off, x+ on, then leave in lowpower */
tc->x = tsc2007_xfer(tsc, READ_X);
/* turn y+ off, x- on; we'll use formula #1 */
tc->z1 = tsc2007_xfer(tsc, READ_Z1);
tc->z2 = tsc2007_xfer(tsc, READ_Z2);
/* Prepare for next touch reading - power down ADC, enable PENIRQ */
tsc2007_xfer(tsc, PWRDOWN);
}
static u32 tsc2007_calculate_pressure(struct tsc2007 *tsc, struct ts_event *tc)
{
u32 rt = 0;
/* range filtering */
if (tc->x == MAX_12BIT)
tc->x = 0;
if (likely(tc->x && tc->z1)) {
/* compute touch pressure resistance using equation #1 */
rt = tc->z2 - tc->z1;
rt *= tc->x;
rt *= tsc->x_plate_ohms;
rt /= tc->z1;
rt = (rt + 2047) >> 12;
}
return rt;
}
static void tsc2007_send_up_event(struct tsc2007 *tsc)
{
struct input_dev *input = tsc->input;
dev_dbg(&tsc->client->dev, "UP\n");
input_report_key(input, BTN_TOUCH, 0);
input_report_abs(input, ABS_PRESSURE, 0);
input_sync(input);
}
static void tsc2007_work(struct work_struct *work)
{
struct tsc2007 *ts =
container_of(to_delayed_work(work), struct tsc2007, work);
bool debounced = false;
struct ts_event tc;
u32 rt;
/*
* NOTE: We can't rely on the pressure to determine the pen down
* state, even though this controller has a pressure sensor.
* The pressure value can fluctuate for quite a while after
* lifting the pen and in some cases may not even settle at the
* expected value.
*
* The only safe way to check for the pen up condition is in the
* work function by reading the pen signal state (it's a GPIO
* and IRQ). Unfortunately such callback is not always available,
* in that case we have rely on the pressure anyway.
*/
if (ts->get_pendown_state) {
if (unlikely(!ts->get_pendown_state())) {
tsc2007_send_up_event(ts);
ts->pendown = false;
goto out;
}
dev_dbg(&ts->client->dev, "pen is still down\n");
}
tsc2007_read_values(ts, &tc);
rt = tsc2007_calculate_pressure(ts, &tc);
if (rt > ts->max_rt) {
/*
* Sample found inconsistent by debouncing or pressure is
* beyond the maximum. Don't report it to user space,
* repeat at least once more the measurement.
*/
dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);
debounced = true;
goto out;
}
if (rt) {
struct input_dev *input = ts->input;
if (!ts->pendown) {
dev_dbg(&ts->client->dev, "DOWN\n");
input_report_key(input, BTN_TOUCH, 1);
ts->pendown = true;
}
input_report_abs(input, ABS_X, tc.x);
input_report_abs(input, ABS_Y, tc.y);
input_report_abs(input, ABS_PRESSURE, rt);
input_sync(input);
dev_dbg(&ts->client->dev, "point(%4d,%4d), pressure (%4u)\n",
tc.x, tc.y, rt);
} else if (!ts->get_pendown_state && ts->pendown) {
/*
* We don't have callback to check pendown state, so we
* have to assume that since pressure reported is 0 the
* pen was lifted up.
*/
tsc2007_send_up_event(ts);
ts->pendown = false;
}
out:
if (ts->pendown || debounced)
schedule_delayed_work(&ts->work,
msecs_to_jiffies(ts->poll_period));
else
enable_irq(ts->irq);
}
static irqreturn_t tsc2007_irq(int irq, void *handle)
{
struct tsc2007 *ts = handle;
if (!ts->get_pendown_state || likely(ts->get_pendown_state())) {
disable_irq_nosync(ts->irq);
schedule_delayed_work(&ts->work,
msecs_to_jiffies(ts->poll_delay));
}
if (ts->clear_penirq)
ts->clear_penirq();
return IRQ_HANDLED;
}
static void tsc2007_free_irq(struct tsc2007 *ts)
{
free_irq(ts->irq, ts);
if (cancel_delayed_work_sync(&ts->work)) {
/*
* Work was pending, therefore we need to enable
* IRQ here to balance the disable_irq() done in the
* interrupt handler.
*/
enable_irq(ts->irq);
}
}
static int __devinit tsc2007_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct tsc2007 *ts;
struct tsc2007_platform_data *pdata = client->dev.platform_data;
struct input_dev *input_dev;
int err;
if (!pdata) {
dev_err(&client->dev, "platform data is required!\n");
return -EINVAL;
}
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_READ_WORD_DATA))
return -EIO;
ts = kzalloc(sizeof(struct tsc2007), GFP_KERNEL);
input_dev = input_allocate_device();
if (!ts || !input_dev) {
err = -ENOMEM;
goto err_free_mem;
}
ts->client = client;
ts->irq = client->irq;
ts->input = input_dev;
INIT_DELAYED_WORK(&ts->work, tsc2007_work);
ts->model = pdata->model;
ts->x_plate_ohms = pdata->x_plate_ohms;
ts->max_rt = pdata->max_rt ? : MAX_12BIT;
ts->poll_delay = pdata->poll_delay ? : 1;
ts->poll_period = pdata->poll_period ? : 1;
ts->get_pendown_state = pdata->get_pendown_state;
ts->clear_penirq = pdata->clear_penirq;
snprintf(ts->phys, sizeof(ts->phys),
"%s/input0", dev_name(&client->dev));
input_dev->name = "TSC2007 Touchscreen";
input_dev->phys = ts->phys;
input_dev->id.bustype = BUS_I2C;
input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, pdata->fuzzx, 0);
input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, pdata->fuzzy, 0);
input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT,
pdata->fuzzz, 0);
if (pdata->init_platform_hw)
pdata->init_platform_hw();
err = request_irq(ts->irq, tsc2007_irq, 0,
client->dev.driver->name, ts);
if (err < 0) {
dev_err(&client->dev, "irq %d busy?\n", ts->irq);
goto err_free_mem;
}
/* Prepare for touch readings - power down ADC and enable PENIRQ */
err = tsc2007_xfer(ts, PWRDOWN);
if (err < 0)
goto err_free_irq;
err = input_register_device(input_dev);
if (err)
goto err_free_irq;
i2c_set_clientdata(client, ts);
return 0;
err_free_irq:
tsc2007_free_irq(ts);
if (pdata->exit_platform_hw)
pdata->exit_platform_hw();
err_free_mem:
input_free_device(input_dev);
kfree(ts);
return err;
}
static int __devexit tsc2007_remove(struct i2c_client *client)
{
struct tsc2007 *ts = i2c_get_clientdata(client);
struct tsc2007_platform_data *pdata = client->dev.platform_data;
tsc2007_free_irq(ts);
if (pdata->exit_platform_hw)
pdata->exit_platform_hw();
input_unregister_device(ts->input);
kfree(ts);
return 0;
}
static const struct i2c_device_id tsc2007_idtable[] = {
{ "tsc2007", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, tsc2007_idtable);
static struct i2c_driver tsc2007_driver = {
.driver = {
.owner = THIS_MODULE,
.name = "tsc2007"
},
.id_table = tsc2007_idtable,
.probe = tsc2007_probe,
.remove = __devexit_p(tsc2007_remove),
};
static int __init tsc2007_init(void)
{
return i2c_add_driver(&tsc2007_driver);
}
static void __exit tsc2007_exit(void)
{
i2c_del_driver(&tsc2007_driver);
}
module_init(tsc2007_init);
module_exit(tsc2007_exit);
MODULE_AUTHOR("Kwangwoo Lee <kwlee@mtekvision.com>");
MODULE_DESCRIPTION("TSC2007 TouchScreen Driver");
MODULE_LICENSE("GPL");
|