Kwangwoo Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 1 | /* |
| 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 Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 24 | #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 | |
Richard Röjfors | 75fba3b | 2009-07-24 22:01:39 -0700 | [diff] [blame^] | 30 | #define TS_POLL_PERIOD msecs_to_jiffies(1) /* ms delay between samples */ |
Kwangwoo Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 31 | |
| 32 | #define TSC2007_MEASURE_TEMP0 (0x0 << 4) |
| 33 | #define TSC2007_MEASURE_AUX (0x2 << 4) |
| 34 | #define TSC2007_MEASURE_TEMP1 (0x4 << 4) |
| 35 | #define TSC2007_ACTIVATE_XN (0x8 << 4) |
| 36 | #define TSC2007_ACTIVATE_YN (0x9 << 4) |
| 37 | #define TSC2007_ACTIVATE_YP_XN (0xa << 4) |
| 38 | #define TSC2007_SETUP (0xb << 4) |
| 39 | #define TSC2007_MEASURE_X (0xc << 4) |
| 40 | #define TSC2007_MEASURE_Y (0xd << 4) |
| 41 | #define TSC2007_MEASURE_Z1 (0xe << 4) |
| 42 | #define TSC2007_MEASURE_Z2 (0xf << 4) |
| 43 | |
| 44 | #define TSC2007_POWER_OFF_IRQ_EN (0x0 << 2) |
| 45 | #define TSC2007_ADC_ON_IRQ_DIS0 (0x1 << 2) |
| 46 | #define TSC2007_ADC_OFF_IRQ_EN (0x2 << 2) |
| 47 | #define TSC2007_ADC_ON_IRQ_DIS1 (0x3 << 2) |
| 48 | |
| 49 | #define TSC2007_12BIT (0x0 << 1) |
| 50 | #define TSC2007_8BIT (0x1 << 1) |
| 51 | |
| 52 | #define MAX_12BIT ((1 << 12) - 1) |
| 53 | |
| 54 | #define ADC_ON_12BIT (TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0) |
| 55 | |
| 56 | #define READ_Y (ADC_ON_12BIT | TSC2007_MEASURE_Y) |
| 57 | #define READ_Z1 (ADC_ON_12BIT | TSC2007_MEASURE_Z1) |
| 58 | #define READ_Z2 (ADC_ON_12BIT | TSC2007_MEASURE_Z2) |
| 59 | #define READ_X (ADC_ON_12BIT | TSC2007_MEASURE_X) |
| 60 | #define PWRDOWN (TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN) |
| 61 | |
| 62 | struct ts_event { |
| 63 | u16 x; |
| 64 | u16 y; |
| 65 | u16 z1, z2; |
| 66 | }; |
| 67 | |
| 68 | struct tsc2007 { |
| 69 | struct input_dev *input; |
| 70 | char phys[32]; |
Richard Röjfors | 75fba3b | 2009-07-24 22:01:39 -0700 | [diff] [blame^] | 71 | struct delayed_work work; |
Kwangwoo Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 72 | struct ts_event tc; |
| 73 | |
| 74 | struct i2c_client *client; |
| 75 | |
Kwangwoo Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 76 | u16 model; |
| 77 | u16 x_plate_ohms; |
| 78 | |
| 79 | unsigned pendown; |
| 80 | int irq; |
| 81 | |
| 82 | int (*get_pendown_state)(void); |
| 83 | void (*clear_penirq)(void); |
| 84 | }; |
| 85 | |
| 86 | static 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 | |
| 108 | static void tsc2007_send_event(void *tsc) |
| 109 | { |
| 110 | struct tsc2007 *ts = tsc; |
| 111 | u32 rt; |
| 112 | u16 x, y, z1, z2; |
| 113 | |
| 114 | x = ts->tc.x; |
| 115 | y = ts->tc.y; |
| 116 | z1 = ts->tc.z1; |
| 117 | z2 = ts->tc.z2; |
| 118 | |
| 119 | /* range filtering */ |
| 120 | if (x == MAX_12BIT) |
| 121 | x = 0; |
| 122 | |
| 123 | if (likely(x && z1)) { |
| 124 | /* compute touch pressure resistance using equation #1 */ |
| 125 | rt = z2; |
| 126 | rt -= z1; |
| 127 | rt *= x; |
| 128 | rt *= ts->x_plate_ohms; |
| 129 | rt /= z1; |
| 130 | rt = (rt + 2047) >> 12; |
| 131 | } else |
| 132 | rt = 0; |
| 133 | |
| 134 | /* Sample found inconsistent by debouncing or pressure is beyond |
| 135 | * the maximum. Don't report it to user space, repeat at least |
| 136 | * once more the measurement |
| 137 | */ |
| 138 | if (rt > MAX_12BIT) { |
| 139 | dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt); |
| 140 | |
Richard Röjfors | 75fba3b | 2009-07-24 22:01:39 -0700 | [diff] [blame^] | 141 | schedule_delayed_work(&ts->work, TS_POLL_PERIOD); |
Kwangwoo Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 142 | return; |
| 143 | } |
| 144 | |
| 145 | /* NOTE: We can't rely on the pressure to determine the pen down |
| 146 | * state, even this controller has a pressure sensor. The pressure |
| 147 | * value can fluctuate for quite a while after lifting the pen and |
| 148 | * in some cases may not even settle at the expected value. |
| 149 | * |
| 150 | * The only safe way to check for the pen up condition is in the |
Richard Röjfors | 75fba3b | 2009-07-24 22:01:39 -0700 | [diff] [blame^] | 151 | * work function by reading the pen signal state (it's a GPIO and IRQ). |
Kwangwoo Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 152 | */ |
| 153 | if (rt) { |
| 154 | struct input_dev *input = ts->input; |
| 155 | |
| 156 | if (!ts->pendown) { |
| 157 | dev_dbg(&ts->client->dev, "DOWN\n"); |
| 158 | |
| 159 | input_report_key(input, BTN_TOUCH, 1); |
| 160 | ts->pendown = 1; |
| 161 | } |
| 162 | |
| 163 | input_report_abs(input, ABS_X, x); |
| 164 | input_report_abs(input, ABS_Y, y); |
| 165 | input_report_abs(input, ABS_PRESSURE, rt); |
| 166 | |
| 167 | input_sync(input); |
| 168 | |
| 169 | dev_dbg(&ts->client->dev, "point(%4d,%4d), pressure (%4u)\n", |
| 170 | x, y, rt); |
| 171 | } |
| 172 | |
Richard Röjfors | 75fba3b | 2009-07-24 22:01:39 -0700 | [diff] [blame^] | 173 | schedule_delayed_work(&ts->work, TS_POLL_PERIOD); |
Kwangwoo Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 174 | } |
| 175 | |
| 176 | static int tsc2007_read_values(struct tsc2007 *tsc) |
| 177 | { |
| 178 | /* y- still on; turn on only y+ (and ADC) */ |
| 179 | tsc->tc.y = tsc2007_xfer(tsc, READ_Y); |
| 180 | |
| 181 | /* turn y- off, x+ on, then leave in lowpower */ |
| 182 | tsc->tc.x = tsc2007_xfer(tsc, READ_X); |
| 183 | |
| 184 | /* turn y+ off, x- on; we'll use formula #1 */ |
| 185 | tsc->tc.z1 = tsc2007_xfer(tsc, READ_Z1); |
| 186 | tsc->tc.z2 = tsc2007_xfer(tsc, READ_Z2); |
| 187 | |
| 188 | /* power down */ |
| 189 | tsc2007_xfer(tsc, PWRDOWN); |
| 190 | |
| 191 | return 0; |
| 192 | } |
| 193 | |
Richard Röjfors | 75fba3b | 2009-07-24 22:01:39 -0700 | [diff] [blame^] | 194 | static void tsc2007_work(struct work_struct *work) |
Kwangwoo Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 195 | { |
Richard Röjfors | 75fba3b | 2009-07-24 22:01:39 -0700 | [diff] [blame^] | 196 | struct tsc2007 *ts = |
| 197 | container_of(to_delayed_work(work), struct tsc2007, work); |
Kwangwoo Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 198 | if (unlikely(!ts->get_pendown_state() && ts->pendown)) { |
| 199 | struct input_dev *input = ts->input; |
| 200 | |
| 201 | dev_dbg(&ts->client->dev, "UP\n"); |
| 202 | |
| 203 | input_report_key(input, BTN_TOUCH, 0); |
| 204 | input_report_abs(input, ABS_PRESSURE, 0); |
| 205 | input_sync(input); |
| 206 | |
| 207 | ts->pendown = 0; |
| 208 | enable_irq(ts->irq); |
| 209 | } else { |
| 210 | /* pen is still down, continue with the measurement */ |
| 211 | dev_dbg(&ts->client->dev, "pen is still down\n"); |
| 212 | |
| 213 | tsc2007_read_values(ts); |
| 214 | tsc2007_send_event(ts); |
| 215 | } |
Kwangwoo Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 216 | } |
| 217 | |
| 218 | static irqreturn_t tsc2007_irq(int irq, void *handle) |
| 219 | { |
| 220 | struct tsc2007 *ts = handle; |
Kwangwoo Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 221 | |
| 222 | if (likely(ts->get_pendown_state())) { |
Ben Nizette | 29fa98b | 2009-04-17 20:35:57 -0700 | [diff] [blame] | 223 | disable_irq_nosync(ts->irq); |
Richard Röjfors | 75fba3b | 2009-07-24 22:01:39 -0700 | [diff] [blame^] | 224 | schedule_delayed_work(&ts->work, 0); |
Kwangwoo Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 225 | } |
| 226 | |
| 227 | if (ts->clear_penirq) |
| 228 | ts->clear_penirq(); |
| 229 | |
Kwangwoo Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 230 | return IRQ_HANDLED; |
| 231 | } |
| 232 | |
| 233 | static int tsc2007_probe(struct i2c_client *client, |
| 234 | const struct i2c_device_id *id) |
| 235 | { |
| 236 | struct tsc2007 *ts; |
| 237 | struct tsc2007_platform_data *pdata = pdata = client->dev.platform_data; |
| 238 | struct input_dev *input_dev; |
| 239 | int err; |
| 240 | |
Kwangwoo Lee | 78f7f36 | 2009-05-15 19:14:35 -0700 | [diff] [blame] | 241 | if (!pdata || !pdata->get_pendown_state) { |
Kwangwoo Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 242 | dev_err(&client->dev, "platform data is required!\n"); |
| 243 | return -EINVAL; |
| 244 | } |
| 245 | |
| 246 | if (!i2c_check_functionality(client->adapter, |
| 247 | I2C_FUNC_SMBUS_READ_WORD_DATA)) |
| 248 | return -EIO; |
| 249 | |
| 250 | ts = kzalloc(sizeof(struct tsc2007), GFP_KERNEL); |
| 251 | input_dev = input_allocate_device(); |
| 252 | if (!ts || !input_dev) { |
| 253 | err = -ENOMEM; |
| 254 | goto err_free_mem; |
| 255 | } |
| 256 | |
| 257 | ts->client = client; |
| 258 | i2c_set_clientdata(client, ts); |
| 259 | |
| 260 | ts->input = input_dev; |
| 261 | |
Kwangwoo Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 262 | ts->model = pdata->model; |
| 263 | ts->x_plate_ohms = pdata->x_plate_ohms; |
| 264 | ts->get_pendown_state = pdata->get_pendown_state; |
| 265 | ts->clear_penirq = pdata->clear_penirq; |
| 266 | |
| 267 | pdata->init_platform_hw(); |
| 268 | |
Kay Sievers | 4e8718a | 2009-01-29 22:56:08 -0800 | [diff] [blame] | 269 | snprintf(ts->phys, sizeof(ts->phys), |
| 270 | "%s/input0", dev_name(&client->dev)); |
Kwangwoo Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 271 | |
| 272 | input_dev->name = "TSC2007 Touchscreen"; |
| 273 | input_dev->phys = ts->phys; |
| 274 | input_dev->id.bustype = BUS_I2C; |
| 275 | |
| 276 | input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); |
| 277 | input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); |
| 278 | |
| 279 | input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0); |
| 280 | input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0); |
| 281 | input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0); |
| 282 | |
| 283 | tsc2007_read_values(ts); |
| 284 | |
| 285 | ts->irq = client->irq; |
| 286 | |
Richard Röjfors | 75fba3b | 2009-07-24 22:01:39 -0700 | [diff] [blame^] | 287 | INIT_DELAYED_WORK(&ts->work, tsc2007_work); |
| 288 | |
Kwangwoo Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 289 | err = request_irq(ts->irq, tsc2007_irq, 0, |
| 290 | client->dev.driver->name, ts); |
| 291 | if (err < 0) { |
| 292 | dev_err(&client->dev, "irq %d busy?\n", ts->irq); |
| 293 | goto err_free_mem; |
| 294 | } |
| 295 | |
| 296 | err = input_register_device(input_dev); |
| 297 | if (err) |
| 298 | goto err_free_irq; |
| 299 | |
| 300 | dev_info(&client->dev, "registered with irq (%d)\n", ts->irq); |
| 301 | |
| 302 | return 0; |
| 303 | |
| 304 | err_free_irq: |
| 305 | free_irq(ts->irq, ts); |
Kwangwoo Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 306 | err_free_mem: |
| 307 | input_free_device(input_dev); |
| 308 | kfree(ts); |
| 309 | return err; |
| 310 | } |
| 311 | |
| 312 | static int tsc2007_remove(struct i2c_client *client) |
| 313 | { |
| 314 | struct tsc2007 *ts = i2c_get_clientdata(client); |
| 315 | struct tsc2007_platform_data *pdata; |
| 316 | |
Richard Röjfors | 75fba3b | 2009-07-24 22:01:39 -0700 | [diff] [blame^] | 317 | cancel_delayed_work_sync(&ts->work); |
| 318 | |
Kwangwoo Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 319 | pdata = client->dev.platform_data; |
| 320 | pdata->exit_platform_hw(); |
| 321 | |
| 322 | free_irq(ts->irq, ts); |
Kwangwoo Lee | 50b6f1f | 2008-12-20 04:26:01 -0500 | [diff] [blame] | 323 | input_unregister_device(ts->input); |
| 324 | kfree(ts); |
| 325 | |
| 326 | return 0; |
| 327 | } |
| 328 | |
| 329 | static struct i2c_device_id tsc2007_idtable[] = { |
| 330 | { "tsc2007", 0 }, |
| 331 | { } |
| 332 | }; |
| 333 | |
| 334 | MODULE_DEVICE_TABLE(i2c, tsc2007_idtable); |
| 335 | |
| 336 | static struct i2c_driver tsc2007_driver = { |
| 337 | .driver = { |
| 338 | .owner = THIS_MODULE, |
| 339 | .name = "tsc2007" |
| 340 | }, |
| 341 | .id_table = tsc2007_idtable, |
| 342 | .probe = tsc2007_probe, |
| 343 | .remove = tsc2007_remove, |
| 344 | }; |
| 345 | |
| 346 | static int __init tsc2007_init(void) |
| 347 | { |
| 348 | return i2c_add_driver(&tsc2007_driver); |
| 349 | } |
| 350 | |
| 351 | static void __exit tsc2007_exit(void) |
| 352 | { |
| 353 | i2c_del_driver(&tsc2007_driver); |
| 354 | } |
| 355 | |
| 356 | module_init(tsc2007_init); |
| 357 | module_exit(tsc2007_exit); |
| 358 | |
| 359 | MODULE_AUTHOR("Kwangwoo Lee <kwlee@mtekvision.com>"); |
| 360 | MODULE_DESCRIPTION("TSC2007 TouchScreen Driver"); |
| 361 | MODULE_LICENSE("GPL"); |