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