1 /* 2 * Touchscreen driver for UCB1x00-based touchscreens 3 * 4 * Copyright (C) 2001 Russell King, All Rights Reserved. 5 * Copyright (C) 2005 Pavel Machek 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 * 21-Jan-2002 <jco@ict.es> : 12 * 13 * Added support for synchronous A/D mode. This mode is useful to 14 * avoid noise induced in the touchpanel by the LCD, provided that 15 * the UCB1x00 has a valid LCD sync signal routed to its ADCSYNC pin. 16 * It is important to note that the signal connected to the ADCSYNC 17 * pin should provide pulses even when the LCD is blanked, otherwise 18 * a pen touch needed to unblank the LCD will never be read. 19 */ 20 #include <linux/module.h> 21 #include <linux/moduleparam.h> 22 #include <linux/init.h> 23 #include <linux/smp.h> 24 #include <linux/sched.h> 25 #include <linux/completion.h> 26 #include <linux/delay.h> 27 #include <linux/string.h> 28 #include <linux/input.h> 29 #include <linux/device.h> 30 #include <linux/freezer.h> 31 #include <linux/slab.h> 32 #include <linux/kthread.h> 33 #include <linux/mfd/ucb1x00.h> 34 35 #include <mach/dma.h> 36 #include <mach/collie.h> 37 #include <asm/mach-types.h> 38 39 40 41 struct ucb1x00_ts { 42 struct input_dev *idev; 43 struct ucb1x00 *ucb; 44 45 wait_queue_head_t irq_wait; 46 struct task_struct *rtask; 47 u16 x_res; 48 u16 y_res; 49 50 unsigned int restart:1; 51 unsigned int adcsync:1; 52 }; 53 54 static int adcsync; 55 56 static inline void ucb1x00_ts_evt_add(struct ucb1x00_ts *ts, u16 pressure, u16 x, u16 y) 57 { 58 struct input_dev *idev = ts->idev; 59 60 input_report_abs(idev, ABS_X, x); 61 input_report_abs(idev, ABS_Y, y); 62 input_report_abs(idev, ABS_PRESSURE, pressure); 63 input_sync(idev); 64 } 65 66 static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts) 67 { 68 struct input_dev *idev = ts->idev; 69 70 input_report_abs(idev, ABS_PRESSURE, 0); 71 input_sync(idev); 72 } 73 74 /* 75 * Switch to interrupt mode. 76 */ 77 static inline void ucb1x00_ts_mode_int(struct ucb1x00_ts *ts) 78 { 79 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 80 UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW | 81 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND | 82 UCB_TS_CR_MODE_INT); 83 } 84 85 /* 86 * Switch to pressure mode, and read pressure. We don't need to wait 87 * here, since both plates are being driven. 88 */ 89 static inline unsigned int ucb1x00_ts_read_pressure(struct ucb1x00_ts *ts) 90 { 91 if (machine_is_collie()) { 92 ucb1x00_io_write(ts->ucb, COLLIE_TC35143_GPIO_TBL_CHK, 0); 93 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 94 UCB_TS_CR_TSPX_POW | UCB_TS_CR_TSMX_POW | 95 UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA); 96 97 udelay(55); 98 99 return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_AD2, ts->adcsync); 100 } else { 101 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 102 UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW | 103 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND | 104 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 105 106 return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync); 107 } 108 } 109 110 /* 111 * Switch to X position mode and measure Y plate. We switch the plate 112 * configuration in pressure mode, then switch to position mode. This 113 * gives a faster response time. Even so, we need to wait about 55us 114 * for things to stabilise. 115 */ 116 static inline unsigned int ucb1x00_ts_read_xpos(struct ucb1x00_ts *ts) 117 { 118 if (machine_is_collie()) 119 ucb1x00_io_write(ts->ucb, 0, COLLIE_TC35143_GPIO_TBL_CHK); 120 else { 121 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 122 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | 123 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 124 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 125 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | 126 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 127 } 128 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 129 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | 130 UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA); 131 132 udelay(55); 133 134 return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync); 135 } 136 137 /* 138 * Switch to Y position mode and measure X plate. We switch the plate 139 * configuration in pressure mode, then switch to position mode. This 140 * gives a faster response time. Even so, we need to wait about 55us 141 * for things to stabilise. 142 */ 143 static inline unsigned int ucb1x00_ts_read_ypos(struct ucb1x00_ts *ts) 144 { 145 if (machine_is_collie()) 146 ucb1x00_io_write(ts->ucb, 0, COLLIE_TC35143_GPIO_TBL_CHK); 147 else { 148 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 149 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | 150 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 151 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 152 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | 153 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 154 } 155 156 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 157 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | 158 UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA); 159 160 udelay(55); 161 162 return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPX, ts->adcsync); 163 } 164 165 /* 166 * Switch to X plate resistance mode. Set MX to ground, PX to 167 * supply. Measure current. 168 */ 169 static inline unsigned int ucb1x00_ts_read_xres(struct ucb1x00_ts *ts) 170 { 171 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 172 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | 173 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 174 return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync); 175 } 176 177 /* 178 * Switch to Y plate resistance mode. Set MY to ground, PY to 179 * supply. Measure current. 180 */ 181 static inline unsigned int ucb1x00_ts_read_yres(struct ucb1x00_ts *ts) 182 { 183 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 184 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | 185 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 186 return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync); 187 } 188 189 static inline int ucb1x00_ts_pen_down(struct ucb1x00_ts *ts) 190 { 191 unsigned int val = ucb1x00_reg_read(ts->ucb, UCB_TS_CR); 192 193 if (machine_is_collie()) 194 return (!(val & (UCB_TS_CR_TSPX_LOW))); 195 else 196 return (val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW)); 197 } 198 199 /* 200 * This is a RT kernel thread that handles the ADC accesses 201 * (mainly so we can use semaphores in the UCB1200 core code 202 * to serialise accesses to the ADC). 203 */ 204 static int ucb1x00_thread(void *_ts) 205 { 206 struct ucb1x00_ts *ts = _ts; 207 DECLARE_WAITQUEUE(wait, current); 208 int valid = 0; 209 210 set_freezable(); 211 add_wait_queue(&ts->irq_wait, &wait); 212 while (!kthread_should_stop()) { 213 unsigned int x, y, p; 214 signed long timeout; 215 216 ts->restart = 0; 217 218 ucb1x00_adc_enable(ts->ucb); 219 220 x = ucb1x00_ts_read_xpos(ts); 221 y = ucb1x00_ts_read_ypos(ts); 222 p = ucb1x00_ts_read_pressure(ts); 223 224 /* 225 * Switch back to interrupt mode. 226 */ 227 ucb1x00_ts_mode_int(ts); 228 ucb1x00_adc_disable(ts->ucb); 229 230 msleep(10); 231 232 ucb1x00_enable(ts->ucb); 233 234 235 if (ucb1x00_ts_pen_down(ts)) { 236 set_current_state(TASK_INTERRUPTIBLE); 237 238 ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, machine_is_collie() ? UCB_RISING : UCB_FALLING); 239 ucb1x00_disable(ts->ucb); 240 241 /* 242 * If we spat out a valid sample set last time, 243 * spit out a "pen off" sample here. 244 */ 245 if (valid) { 246 ucb1x00_ts_event_release(ts); 247 valid = 0; 248 } 249 250 timeout = MAX_SCHEDULE_TIMEOUT; 251 } else { 252 ucb1x00_disable(ts->ucb); 253 254 /* 255 * Filtering is policy. Policy belongs in user 256 * space. We therefore leave it to user space 257 * to do any filtering they please. 258 */ 259 if (!ts->restart) { 260 ucb1x00_ts_evt_add(ts, p, x, y); 261 valid = 1; 262 } 263 264 set_current_state(TASK_INTERRUPTIBLE); 265 timeout = HZ / 100; 266 } 267 268 try_to_freeze(); 269 270 schedule_timeout(timeout); 271 } 272 273 remove_wait_queue(&ts->irq_wait, &wait); 274 275 ts->rtask = NULL; 276 return 0; 277 } 278 279 /* 280 * We only detect touch screen _touches_ with this interrupt 281 * handler, and even then we just schedule our task. 282 */ 283 static void ucb1x00_ts_irq(int idx, void *id) 284 { 285 struct ucb1x00_ts *ts = id; 286 287 ucb1x00_disable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING); 288 wake_up(&ts->irq_wait); 289 } 290 291 static int ucb1x00_ts_open(struct input_dev *idev) 292 { 293 struct ucb1x00_ts *ts = input_get_drvdata(idev); 294 int ret = 0; 295 296 BUG_ON(ts->rtask); 297 298 init_waitqueue_head(&ts->irq_wait); 299 ret = ucb1x00_hook_irq(ts->ucb, UCB_IRQ_TSPX, ucb1x00_ts_irq, ts); 300 if (ret < 0) 301 goto out; 302 303 /* 304 * If we do this at all, we should allow the user to 305 * measure and read the X and Y resistance at any time. 306 */ 307 ucb1x00_adc_enable(ts->ucb); 308 ts->x_res = ucb1x00_ts_read_xres(ts); 309 ts->y_res = ucb1x00_ts_read_yres(ts); 310 ucb1x00_adc_disable(ts->ucb); 311 312 ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd"); 313 if (!IS_ERR(ts->rtask)) { 314 ret = 0; 315 } else { 316 ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts); 317 ts->rtask = NULL; 318 ret = -EFAULT; 319 } 320 321 out: 322 return ret; 323 } 324 325 /* 326 * Release touchscreen resources. Disable IRQs. 327 */ 328 static void ucb1x00_ts_close(struct input_dev *idev) 329 { 330 struct ucb1x00_ts *ts = input_get_drvdata(idev); 331 332 if (ts->rtask) 333 kthread_stop(ts->rtask); 334 335 ucb1x00_enable(ts->ucb); 336 ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts); 337 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0); 338 ucb1x00_disable(ts->ucb); 339 } 340 341 #ifdef CONFIG_PM 342 static int ucb1x00_ts_resume(struct ucb1x00_dev *dev) 343 { 344 struct ucb1x00_ts *ts = dev->priv; 345 346 if (ts->rtask != NULL) { 347 /* 348 * Restart the TS thread to ensure the 349 * TS interrupt mode is set up again 350 * after sleep. 351 */ 352 ts->restart = 1; 353 wake_up(&ts->irq_wait); 354 } 355 return 0; 356 } 357 #else 358 #define ucb1x00_ts_resume NULL 359 #endif 360 361 362 /* 363 * Initialisation. 364 */ 365 static int ucb1x00_ts_add(struct ucb1x00_dev *dev) 366 { 367 struct ucb1x00_ts *ts; 368 struct input_dev *idev; 369 int err; 370 371 ts = kzalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL); 372 idev = input_allocate_device(); 373 if (!ts || !idev) { 374 err = -ENOMEM; 375 goto fail; 376 } 377 378 ts->ucb = dev->ucb; 379 ts->idev = idev; 380 ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC; 381 382 idev->name = "Touchscreen panel"; 383 idev->id.product = ts->ucb->id; 384 idev->open = ucb1x00_ts_open; 385 idev->close = ucb1x00_ts_close; 386 387 __set_bit(EV_ABS, idev->evbit); 388 389 input_set_drvdata(idev, ts); 390 391 ucb1x00_adc_enable(ts->ucb); 392 ts->x_res = ucb1x00_ts_read_xres(ts); 393 ts->y_res = ucb1x00_ts_read_yres(ts); 394 ucb1x00_adc_disable(ts->ucb); 395 396 input_set_abs_params(idev, ABS_X, 0, ts->x_res, 0, 0); 397 input_set_abs_params(idev, ABS_Y, 0, ts->y_res, 0, 0); 398 input_set_abs_params(idev, ABS_PRESSURE, 0, 0, 0, 0); 399 400 err = input_register_device(idev); 401 if (err) 402 goto fail; 403 404 dev->priv = ts; 405 406 return 0; 407 408 fail: 409 input_free_device(idev); 410 kfree(ts); 411 return err; 412 } 413 414 static void ucb1x00_ts_remove(struct ucb1x00_dev *dev) 415 { 416 struct ucb1x00_ts *ts = dev->priv; 417 418 input_unregister_device(ts->idev); 419 kfree(ts); 420 } 421 422 static struct ucb1x00_driver ucb1x00_ts_driver = { 423 .add = ucb1x00_ts_add, 424 .remove = ucb1x00_ts_remove, 425 .resume = ucb1x00_ts_resume, 426 }; 427 428 static int __init ucb1x00_ts_init(void) 429 { 430 return ucb1x00_register_driver(&ucb1x00_ts_driver); 431 } 432 433 static void __exit ucb1x00_ts_exit(void) 434 { 435 ucb1x00_unregister_driver(&ucb1x00_ts_driver); 436 } 437 438 module_param(adcsync, int, 0444); 439 module_init(ucb1x00_ts_init); 440 module_exit(ucb1x00_ts_exit); 441 442 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); 443 MODULE_DESCRIPTION("UCB1x00 touchscreen driver"); 444 MODULE_LICENSE("GPL"); 445