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