1/* 2 * drivers/input/touchscreen/tps6507x_ts.c 3 * 4 * Touchscreen driver for the tps6507x chip. 5 * 6 * Copyright (c) 2009 RidgeRun (todd.fischer@ridgerun.com) 7 * 8 * Credits: 9 * 10 * Using code from tsc2007, MtekVision Co., Ltd. 11 * 12 * For licencing details see kernel-base/COPYING 13 * 14 * TPS65070, TPS65073, TPS650731, and TPS650732 support 15 * 10 bit touch screen interface. 16 */ 17 18#include <linux/module.h> 19#include <linux/workqueue.h> 20#include <linux/slab.h> 21#include <linux/input.h> 22#include <linux/platform_device.h> 23#include <linux/mfd/tps6507x.h> 24#include <linux/input/tps6507x-ts.h> 25#include <linux/delay.h> 26 27#define TSC_DEFAULT_POLL_PERIOD 30 /* ms */ 28#define TPS_DEFAULT_MIN_PRESSURE 0x30 29#define MAX_10BIT ((1 << 10) - 1) 30 31#define TPS6507X_ADCONFIG_CONVERT_TS (TPS6507X_ADCONFIG_AD_ENABLE | \ 32 TPS6507X_ADCONFIG_START_CONVERSION | \ 33 TPS6507X_ADCONFIG_INPUT_REAL_TSC) 34#define TPS6507X_ADCONFIG_POWER_DOWN_TS (TPS6507X_ADCONFIG_INPUT_REAL_TSC) 35 36struct ts_event { 37 u16 x; 38 u16 y; 39 u16 pressure; 40}; 41 42struct tps6507x_ts { 43 struct input_dev *input_dev; 44 struct device *dev; 45 char phys[32]; 46 struct workqueue_struct *wq; 47 struct delayed_work work; 48 unsigned polling; /* polling is active */ 49 struct ts_event tc; 50 struct tps6507x_dev *mfd; 51 u16 model; 52 unsigned pendown; 53 int irq; 54 void (*clear_penirq)(void); 55 unsigned long poll_period; /* ms */ 56 u16 min_pressure; 57 int vref; /* non-zero to leave vref on */ 58}; 59 60static int tps6507x_read_u8(struct tps6507x_ts *tsc, u8 reg, u8 *data) 61{ 62 int err; 63 64 err = tsc->mfd->read_dev(tsc->mfd, reg, 1, data); 65 66 if (err) 67 return err; 68 69 return 0; 70} 71 72static int tps6507x_write_u8(struct tps6507x_ts *tsc, u8 reg, u8 data) 73{ 74 return tsc->mfd->write_dev(tsc->mfd, reg, 1, &data); 75} 76 77static s32 tps6507x_adc_conversion(struct tps6507x_ts *tsc, 78 u8 tsc_mode, u16 *value) 79{ 80 s32 ret; 81 u8 adc_status; 82 u8 result; 83 84 /* Route input signal to A/D converter */ 85 86 ret = tps6507x_write_u8(tsc, TPS6507X_REG_TSCMODE, tsc_mode); 87 if (ret) { 88 dev_err(tsc->dev, "TSC mode read failed\n"); 89 goto err; 90 } 91 92 /* Start A/D conversion */ 93 94 ret = tps6507x_write_u8(tsc, TPS6507X_REG_ADCONFIG, 95 TPS6507X_ADCONFIG_CONVERT_TS); 96 if (ret) { 97 dev_err(tsc->dev, "ADC config write failed\n"); 98 return ret; 99 } 100 101 do { 102 ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADCONFIG, 103 &adc_status); 104 if (ret) { 105 dev_err(tsc->dev, "ADC config read failed\n"); 106 goto err; 107 } 108 } while (adc_status & TPS6507X_ADCONFIG_START_CONVERSION); 109 110 ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADRESULT_2, &result); 111 if (ret) { 112 dev_err(tsc->dev, "ADC result 2 read failed\n"); 113 goto err; 114 } 115 116 *value = (result & TPS6507X_REG_ADRESULT_2_MASK) << 8; 117 118 ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADRESULT_1, &result); 119 if (ret) { 120 dev_err(tsc->dev, "ADC result 1 read failed\n"); 121 goto err; 122 } 123 124 *value |= result; 125 126 dev_dbg(tsc->dev, "TSC channel %d = 0x%X\n", tsc_mode, *value); 127 128err: 129 return ret; 130} 131 132/* Need to call tps6507x_adc_standby() after using A/D converter for the 133 * touch screen interrupt to work properly. 134 */ 135 136static s32 tps6507x_adc_standby(struct tps6507x_ts *tsc) 137{ 138 s32 ret; 139 s32 loops = 0; 140 u8 val; 141 142 ret = tps6507x_write_u8(tsc, TPS6507X_REG_ADCONFIG, 143 TPS6507X_ADCONFIG_INPUT_TSC); 144 if (ret) 145 return ret; 146 147 ret = tps6507x_write_u8(tsc, TPS6507X_REG_TSCMODE, 148 TPS6507X_TSCMODE_STANDBY); 149 if (ret) 150 return ret; 151 152 ret = tps6507x_read_u8(tsc, TPS6507X_REG_INT, &val); 153 if (ret) 154 return ret; 155 156 while (val & TPS6507X_REG_TSC_INT) { 157 mdelay(10); 158 ret = tps6507x_read_u8(tsc, TPS6507X_REG_INT, &val); 159 if (ret) 160 return ret; 161 loops++; 162 } 163 164 return ret; 165} 166 167static void tps6507x_ts_handler(struct work_struct *work) 168{ 169 struct tps6507x_ts *tsc = container_of(work, 170 struct tps6507x_ts, work.work); 171 struct input_dev *input_dev = tsc->input_dev; 172 int pendown; 173 int schd; 174 int poll = 0; 175 s32 ret; 176 177 ret = tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_PRESSURE, 178 &tsc->tc.pressure); 179 if (ret) 180 goto done; 181 182 pendown = tsc->tc.pressure > tsc->min_pressure; 183 184 if (unlikely(!pendown && tsc->pendown)) { 185 dev_dbg(tsc->dev, "UP\n"); 186 input_report_key(input_dev, BTN_TOUCH, 0); 187 input_report_abs(input_dev, ABS_PRESSURE, 0); 188 input_sync(input_dev); 189 tsc->pendown = 0; 190 } 191 192 if (pendown) { 193 194 if (!tsc->pendown) { 195 dev_dbg(tsc->dev, "DOWN\n"); 196 input_report_key(input_dev, BTN_TOUCH, 1); 197 } else 198 dev_dbg(tsc->dev, "still down\n"); 199 200 ret = tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_X_POSITION, 201 &tsc->tc.x); 202 if (ret) 203 goto done; 204 205 ret = tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_Y_POSITION, 206 &tsc->tc.y); 207 if (ret) 208 goto done; 209 210 input_report_abs(input_dev, ABS_X, tsc->tc.x); 211 input_report_abs(input_dev, ABS_Y, tsc->tc.y); 212 input_report_abs(input_dev, ABS_PRESSURE, tsc->tc.pressure); 213 input_sync(input_dev); 214 tsc->pendown = 1; 215 poll = 1; 216 } 217 218done: 219 /* always poll if not using interrupts */ 220 poll = 1; 221 222 if (poll) { 223 schd = queue_delayed_work(tsc->wq, &tsc->work, 224 msecs_to_jiffies(tsc->poll_period)); 225 if (schd) 226 tsc->polling = 1; 227 else { 228 tsc->polling = 0; 229 dev_err(tsc->dev, "re-schedule failed"); 230 } 231 } else 232 tsc->polling = 0; 233 234 ret = tps6507x_adc_standby(tsc); 235} 236 237static int tps6507x_ts_probe(struct platform_device *pdev) 238{ 239 int error; 240 struct tps6507x_ts *tsc; 241 struct tps6507x_dev *tps6507x_dev = dev_get_drvdata(pdev->dev.parent); 242 struct touchscreen_init_data *init_data; 243 struct input_dev *input_dev; 244 struct tps6507x_board *tps_board; 245 int schd; 246 247 /** 248 * tps_board points to pmic related constants 249 * coming from the board-evm file. 250 */ 251 252 tps_board = (struct tps6507x_board *)tps6507x_dev->dev->platform_data; 253 254 if (!tps_board) { 255 dev_err(tps6507x_dev->dev, 256 "Could not find tps6507x platform data\n"); 257 return -EIO; 258 } 259 260 /** 261 * init_data points to array of regulator_init structures 262 * coming from the board-evm file. 263 */ 264 265 init_data = tps_board->tps6507x_ts_init_data; 266 267 tsc = kzalloc(sizeof(struct tps6507x_ts), GFP_KERNEL); 268 if (!tsc) { 269 dev_err(tps6507x_dev->dev, "failed to allocate driver data\n"); 270 error = -ENOMEM; 271 goto err0; 272 } 273 274 tps6507x_dev->ts = tsc; 275 tsc->mfd = tps6507x_dev; 276 tsc->dev = tps6507x_dev->dev; 277 input_dev = input_allocate_device(); 278 if (!input_dev) { 279 dev_err(tsc->dev, "Failed to allocate input device.\n"); 280 error = -ENOMEM; 281 goto err1; 282 } 283 284 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 285 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 286 287 input_set_abs_params(input_dev, ABS_X, 0, MAX_10BIT, 0, 0); 288 input_set_abs_params(input_dev, ABS_Y, 0, MAX_10BIT, 0, 0); 289 input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_10BIT, 0, 0); 290 291 input_dev->name = "TPS6507x Touchscreen"; 292 input_dev->id.bustype = BUS_I2C; 293 input_dev->dev.parent = tsc->dev; 294 295 snprintf(tsc->phys, sizeof(tsc->phys), 296 "%s/input0", dev_name(tsc->dev)); 297 input_dev->phys = tsc->phys; 298 299 dev_dbg(tsc->dev, "device: %s\n", input_dev->phys); 300 301 input_set_drvdata(input_dev, tsc); 302 303 tsc->input_dev = input_dev; 304 305 INIT_DELAYED_WORK(&tsc->work, tps6507x_ts_handler); 306 tsc->wq = create_workqueue("TPS6507x Touchscreen"); 307 308 if (init_data) { 309 tsc->poll_period = init_data->poll_period; 310 tsc->vref = init_data->vref; 311 tsc->min_pressure = init_data->min_pressure; 312 input_dev->id.vendor = init_data->vendor; 313 input_dev->id.product = init_data->product; 314 input_dev->id.version = init_data->version; 315 } else { 316 tsc->poll_period = TSC_DEFAULT_POLL_PERIOD; 317 tsc->min_pressure = TPS_DEFAULT_MIN_PRESSURE; 318 } 319 320 error = tps6507x_adc_standby(tsc); 321 if (error) 322 goto err2; 323 324 error = input_register_device(input_dev); 325 if (error) 326 goto err2; 327 328 schd = queue_delayed_work(tsc->wq, &tsc->work, 329 msecs_to_jiffies(tsc->poll_period)); 330 331 if (schd) 332 tsc->polling = 1; 333 else { 334 tsc->polling = 0; 335 dev_err(tsc->dev, "schedule failed"); 336 goto err2; 337 } 338 339 return 0; 340 341err2: 342 cancel_delayed_work_sync(&tsc->work); 343 destroy_workqueue(tsc->wq); 344 input_free_device(input_dev); 345err1: 346 kfree(tsc); 347 tps6507x_dev->ts = NULL; 348err0: 349 return error; 350} 351 352static int __devexit tps6507x_ts_remove(struct platform_device *pdev) 353{ 354 struct tps6507x_dev *tps6507x_dev = platform_get_drvdata(pdev); 355 struct tps6507x_ts *tsc = tps6507x_dev->ts; 356 struct input_dev *input_dev = tsc->input_dev; 357 358 cancel_delayed_work_sync(&tsc->work); 359 destroy_workqueue(tsc->wq); 360 361 input_free_device(input_dev); 362 363 tps6507x_dev->ts = NULL; 364 kfree(tsc); 365 366 return 0; 367} 368 369static struct platform_driver tps6507x_ts_driver = { 370 .driver = { 371 .name = "tps6507x-ts", 372 .owner = THIS_MODULE, 373 }, 374 .probe = tps6507x_ts_probe, 375 .remove = __devexit_p(tps6507x_ts_remove), 376}; 377 378static int __init tps6507x_ts_init(void) 379{ 380 return platform_driver_register(&tps6507x_ts_driver); 381} 382module_init(tps6507x_ts_init); 383 384static void __exit tps6507x_ts_exit(void) 385{ 386 platform_driver_unregister(&tps6507x_ts_driver); 387} 388module_exit(tps6507x_ts_exit); 389 390MODULE_AUTHOR("Todd Fischer <todd.fischer@ridgerun.com>"); 391MODULE_DESCRIPTION("TPS6507x - TouchScreen driver"); 392MODULE_LICENSE("GPL v2"); 393MODULE_ALIAS("platform:tps6507x-tsc"); 394