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 34 #include <asm/dma.h> 35 #include <asm/semaphore.h> 36 #include <asm/arch/collie.h> 37 #include <asm/mach-types.h> 38 39 #include "ucb1x00.h" 40 41 42 struct ucb1x00_ts { 43 struct input_dev *idev; 44 struct ucb1x00 *ucb; 45 46 wait_queue_head_t irq_wait; 47 struct task_struct *rtask; 48 u16 x_res; 49 u16 y_res; 50 51 unsigned int restart:1; 52 unsigned int adcsync:1; 53 }; 54 55 static int adcsync; 56 57 static inline void ucb1x00_ts_evt_add(struct ucb1x00_ts *ts, u16 pressure, u16 x, u16 y) 58 { 59 struct input_dev *idev = ts->idev; 60 61 input_report_abs(idev, ABS_X, x); 62 input_report_abs(idev, ABS_Y, y); 63 input_report_abs(idev, ABS_PRESSURE, pressure); 64 input_sync(idev); 65 } 66 67 static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts) 68 { 69 struct input_dev *idev = ts->idev; 70 71 input_report_abs(idev, ABS_PRESSURE, 0); 72 input_sync(idev); 73 } 74 75 /* 76 * Switch to interrupt mode. 77 */ 78 static inline void ucb1x00_ts_mode_int(struct ucb1x00_ts *ts) 79 { 80 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 81 UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW | 82 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND | 83 UCB_TS_CR_MODE_INT); 84 } 85 86 /* 87 * Switch to pressure mode, and read pressure. We don't need to wait 88 * here, since both plates are being driven. 89 */ 90 static inline unsigned int ucb1x00_ts_read_pressure(struct ucb1x00_ts *ts) 91 { 92 if (machine_is_collie()) { 93 ucb1x00_io_write(ts->ucb, COLLIE_TC35143_GPIO_TBL_CHK, 0); 94 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 95 UCB_TS_CR_TSPX_POW | UCB_TS_CR_TSMX_POW | 96 UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA); 97 98 udelay(55); 99 100 return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_AD2, ts->adcsync); 101 } else { 102 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 103 UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW | 104 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND | 105 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 106 107 return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync); 108 } 109 } 110 111 /* 112 * Switch to X position mode and measure Y plate. We switch the plate 113 * configuration in pressure mode, then switch to position mode. This 114 * gives a faster response time. Even so, we need to wait about 55us 115 * for things to stabilise. 116 */ 117 static inline unsigned int ucb1x00_ts_read_xpos(struct ucb1x00_ts *ts) 118 { 119 if (machine_is_collie()) 120 ucb1x00_io_write(ts->ucb, 0, COLLIE_TC35143_GPIO_TBL_CHK); 121 else { 122 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 123 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | 124 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 125 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 126 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | 127 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 128 } 129 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 130 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | 131 UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA); 132 133 udelay(55); 134 135 return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync); 136 } 137 138 /* 139 * Switch to Y position mode and measure X plate. We switch the plate 140 * configuration in pressure mode, then switch to position mode. This 141 * gives a faster response time. Even so, we need to wait about 55us 142 * for things to stabilise. 143 */ 144 static inline unsigned int ucb1x00_ts_read_ypos(struct ucb1x00_ts *ts) 145 { 146 if (machine_is_collie()) 147 ucb1x00_io_write(ts->ucb, 0, COLLIE_TC35143_GPIO_TBL_CHK); 148 else { 149 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 150 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | 151 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 152 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 153 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | 154 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 155 } 156 157 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 158 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | 159 UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA); 160 161 udelay(55); 162 163 return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPX, ts->adcsync); 164 } 165 166 /* 167 * Switch to X plate resistance mode. Set MX to ground, PX to 168 * supply. Measure current. 169 */ 170 static inline unsigned int ucb1x00_ts_read_xres(struct ucb1x00_ts *ts) 171 { 172 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 173 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | 174 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 175 return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync); 176 } 177 178 /* 179 * Switch to Y plate resistance mode. Set MY to ground, PY to 180 * supply. Measure current. 181 */ 182 static inline unsigned int ucb1x00_ts_read_yres(struct ucb1x00_ts *ts) 183 { 184 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 185 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | 186 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 187 return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync); 188 } 189 190 static inline int ucb1x00_ts_pen_down(struct ucb1x00_ts *ts) 191 { 192 unsigned int val = ucb1x00_reg_read(ts->ucb, UCB_TS_CR); 193 194 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; 296 297 ucb1x00_disable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING); 298 wake_up(&ts->irq_wait); 299 } 300 301 static int ucb1x00_ts_open(struct input_dev *idev) 302 { 303 struct ucb1x00_ts *ts = idev->private; 304 int ret = 0; 305 306 BUG_ON(ts->rtask); 307 308 init_waitqueue_head(&ts->irq_wait); 309 ret = ucb1x00_hook_irq(ts->ucb, UCB_IRQ_TSPX, ucb1x00_ts_irq, ts); 310 if (ret < 0) 311 goto out; 312 313 /* 314 * If we do this at all, we should allow the user to 315 * measure and read the X and Y resistance at any time. 316 */ 317 ucb1x00_adc_enable(ts->ucb); 318 ts->x_res = ucb1x00_ts_read_xres(ts); 319 ts->y_res = ucb1x00_ts_read_yres(ts); 320 ucb1x00_adc_disable(ts->ucb); 321 322 ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd"); 323 if (!IS_ERR(ts->rtask)) { 324 ret = 0; 325 } else { 326 ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts); 327 ts->rtask = NULL; 328 ret = -EFAULT; 329 } 330 331 out: 332 return ret; 333 } 334 335 /* 336 * Release touchscreen resources. Disable IRQs. 337 */ 338 static void ucb1x00_ts_close(struct input_dev *idev) 339 { 340 struct ucb1x00_ts *ts = idev->private; 341 342 if (ts->rtask) 343 kthread_stop(ts->rtask); 344 345 ucb1x00_enable(ts->ucb); 346 ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts); 347 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0); 348 ucb1x00_disable(ts->ucb); 349 } 350 351 #ifdef CONFIG_PM 352 static int ucb1x00_ts_resume(struct ucb1x00_dev *dev) 353 { 354 struct ucb1x00_ts *ts = dev->priv; 355 356 if (ts->rtask != NULL) { 357 /* 358 * Restart the TS thread to ensure the 359 * TS interrupt mode is set up again 360 * after sleep. 361 */ 362 ts->restart = 1; 363 wake_up(&ts->irq_wait); 364 } 365 return 0; 366 } 367 #else 368 #define ucb1x00_ts_resume NULL 369 #endif 370 371 372 /* 373 * Initialisation. 374 */ 375 static int ucb1x00_ts_add(struct ucb1x00_dev *dev) 376 { 377 struct ucb1x00_ts *ts; 378 struct input_dev *idev; 379 int err; 380 381 ts = kzalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL); 382 idev = input_allocate_device(); 383 if (!ts || !idev) { 384 err = -ENOMEM; 385 goto fail; 386 } 387 388 ts->ucb = dev->ucb; 389 ts->idev = idev; 390 ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC; 391 392 idev->private = ts; 393 idev->name = "Touchscreen panel"; 394 idev->id.product = ts->ucb->id; 395 idev->open = ucb1x00_ts_open; 396 idev->close = ucb1x00_ts_close; 397 398 __set_bit(EV_ABS, idev->evbit); 399 __set_bit(ABS_X, idev->absbit); 400 __set_bit(ABS_Y, idev->absbit); 401 __set_bit(ABS_PRESSURE, idev->absbit); 402 403 err = input_register_device(idev); 404 if (err) 405 goto fail; 406 407 dev->priv = ts; 408 409 return 0; 410 411 fail: 412 input_free_device(idev); 413 kfree(ts); 414 return err; 415 } 416 417 static void ucb1x00_ts_remove(struct ucb1x00_dev *dev) 418 { 419 struct ucb1x00_ts *ts = dev->priv; 420 421 input_unregister_device(ts->idev); 422 kfree(ts); 423 } 424 425 static struct ucb1x00_driver ucb1x00_ts_driver = { 426 .add = ucb1x00_ts_add, 427 .remove = ucb1x00_ts_remove, 428 .resume = ucb1x00_ts_resume, 429 }; 430 431 static int __init ucb1x00_ts_init(void) 432 { 433 return ucb1x00_register_driver(&ucb1x00_ts_driver); 434 } 435 436 static void __exit ucb1x00_ts_exit(void) 437 { 438 ucb1x00_unregister_driver(&ucb1x00_ts_driver); 439 } 440 441 module_param(adcsync, int, 0444); 442 module_init(ucb1x00_ts_init); 443 module_exit(ucb1x00_ts_exit); 444 445 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); 446 MODULE_DESCRIPTION("UCB1x00 touchscreen driver"); 447 MODULE_LICENSE("GPL"); 448