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/smp_lock.h> 25 #include <linux/sched.h> 26 #include <linux/completion.h> 27 #include <linux/delay.h> 28 #include <linux/string.h> 29 #include <linux/input.h> 30 #include <linux/device.h> 31 #include <linux/freezer.h> 32 #include <linux/slab.h> 33 #include <linux/kthread.h> 34 35 #include <asm/dma.h> 36 #include <asm/semaphore.h> 37 #include <asm/arch/collie.h> 38 #include <asm/mach-types.h> 39 40 #include "ucb1x00.h" 41 42 43 struct ucb1x00_ts { 44 struct input_dev *idev; 45 struct ucb1x00 *ucb; 46 47 wait_queue_head_t irq_wait; 48 struct task_struct *rtask; 49 u16 x_res; 50 u16 y_res; 51 52 unsigned int restart:1; 53 unsigned int adcsync:1; 54 }; 55 56 static int adcsync; 57 58 static inline void ucb1x00_ts_evt_add(struct ucb1x00_ts *ts, u16 pressure, u16 x, u16 y) 59 { 60 struct input_dev *idev = ts->idev; 61 62 input_report_abs(idev, ABS_X, x); 63 input_report_abs(idev, ABS_Y, y); 64 input_report_abs(idev, ABS_PRESSURE, pressure); 65 input_sync(idev); 66 } 67 68 static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts) 69 { 70 struct input_dev *idev = ts->idev; 71 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); 194 195 if (machine_is_collie()) 196 return (!(val & (UCB_TS_CR_TSPX_LOW))); 197 else 198 return (val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW)); 199 } 200 201 /* 202 * This is a RT kernel thread that handles the ADC accesses 203 * (mainly so we can use semaphores in the UCB1200 core code 204 * to serialise accesses to the ADC). 205 */ 206 static int ucb1x00_thread(void *_ts) 207 { 208 struct ucb1x00_ts *ts = _ts; 209 struct task_struct *tsk = current; 210 DECLARE_WAITQUEUE(wait, tsk); 211 int valid = 0; 212 213 add_wait_queue(&ts->irq_wait, &wait); 214 while (!kthread_should_stop()) { 215 unsigned int x, y, p; 216 signed long timeout; 217 218 ts->restart = 0; 219 220 ucb1x00_adc_enable(ts->ucb); 221 222 x = ucb1x00_ts_read_xpos(ts); 223 y = ucb1x00_ts_read_ypos(ts); 224 p = ucb1x00_ts_read_pressure(ts); 225 226 /* 227 * Switch back to interrupt mode. 228 */ 229 ucb1x00_ts_mode_int(ts); 230 ucb1x00_adc_disable(ts->ucb); 231 232 msleep(10); 233 234 ucb1x00_enable(ts->ucb); 235 236 237 if (ucb1x00_ts_pen_down(ts)) { 238 set_task_state(tsk, TASK_INTERRUPTIBLE); 239 240 ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, machine_is_collie() ? UCB_RISING : UCB_FALLING); 241 ucb1x00_disable(ts->ucb); 242 243 /* 244 * If we spat out a valid sample set last time, 245 * spit out a "pen off" sample here. 246 */ 247 if (valid) { 248 ucb1x00_ts_event_release(ts); 249 valid = 0; 250 } 251 252 timeout = MAX_SCHEDULE_TIMEOUT; 253 } else { 254 ucb1x00_disable(ts->ucb); 255 256 /* 257 * Filtering is policy. Policy belongs in user 258 * space. We therefore leave it to user space 259 * to do any filtering they please. 260 */ 261 if (!ts->restart) { 262 ucb1x00_ts_evt_add(ts, p, x, y); 263 valid = 1; 264 } 265 266 set_task_state(tsk, TASK_INTERRUPTIBLE); 267 timeout = HZ / 100; 268 } 269 270 try_to_freeze(); 271 272 schedule_timeout(timeout); 273 } 274 275 remove_wait_queue(&ts->irq_wait, &wait); 276 277 ts->rtask = NULL; 278 return 0; 279 } 280 281 /* 282 * We only detect touch screen _touches_ with this interrupt 283 * handler, and even then we just schedule our task. 284 */ 285 static void ucb1x00_ts_irq(int idx, void *id) 286 { 287 struct ucb1x00_ts *ts = id; 288 289 ucb1x00_disable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING); 290 wake_up(&ts->irq_wait); 291 } 292 293 static int ucb1x00_ts_open(struct input_dev *idev) 294 { 295 struct ucb1x00_ts *ts = idev->private; 296 int ret = 0; 297 298 BUG_ON(ts->rtask); 299 300 init_waitqueue_head(&ts->irq_wait); 301 ret = ucb1x00_hook_irq(ts->ucb, UCB_IRQ_TSPX, ucb1x00_ts_irq, ts); 302 if (ret < 0) 303 goto out; 304 305 /* 306 * If we do this at all, we should allow the user to 307 * measure and read the X and Y resistance at any time. 308 */ 309 ucb1x00_adc_enable(ts->ucb); 310 ts->x_res = ucb1x00_ts_read_xres(ts); 311 ts->y_res = ucb1x00_ts_read_yres(ts); 312 ucb1x00_adc_disable(ts->ucb); 313 314 ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd"); 315 if (!IS_ERR(ts->rtask)) { 316 ret = 0; 317 } else { 318 ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts); 319 ts->rtask = NULL; 320 ret = -EFAULT; 321 } 322 323 out: 324 return ret; 325 } 326 327 /* 328 * Release touchscreen resources. Disable IRQs. 329 */ 330 static void ucb1x00_ts_close(struct input_dev *idev) 331 { 332 struct ucb1x00_ts *ts = idev->private; 333 334 if (ts->rtask) 335 kthread_stop(ts->rtask); 336 337 ucb1x00_enable(ts->ucb); 338 ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts); 339 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0); 340 ucb1x00_disable(ts->ucb); 341 } 342 343 #ifdef CONFIG_PM 344 static int ucb1x00_ts_resume(struct ucb1x00_dev *dev) 345 { 346 struct ucb1x00_ts *ts = dev->priv; 347 348 if (ts->rtask != NULL) { 349 /* 350 * Restart the TS thread to ensure the 351 * TS interrupt mode is set up again 352 * after sleep. 353 */ 354 ts->restart = 1; 355 wake_up(&ts->irq_wait); 356 } 357 return 0; 358 } 359 #else 360 #define ucb1x00_ts_resume NULL 361 #endif 362 363 364 /* 365 * Initialisation. 366 */ 367 static int ucb1x00_ts_add(struct ucb1x00_dev *dev) 368 { 369 struct ucb1x00_ts *ts; 370 struct input_dev *idev; 371 int err; 372 373 ts = kzalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL); 374 idev = input_allocate_device(); 375 if (!ts || !idev) { 376 err = -ENOMEM; 377 goto fail; 378 } 379 380 ts->ucb = dev->ucb; 381 ts->idev = idev; 382 ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC; 383 384 idev->private = ts; 385 idev->name = "Touchscreen panel"; 386 idev->id.product = ts->ucb->id; 387 idev->open = ucb1x00_ts_open; 388 idev->close = ucb1x00_ts_close; 389 390 __set_bit(EV_ABS, idev->evbit); 391 __set_bit(ABS_X, idev->absbit); 392 __set_bit(ABS_Y, idev->absbit); 393 __set_bit(ABS_PRESSURE, idev->absbit); 394 395 err = input_register_device(idev); 396 if (err) 397 goto fail; 398 399 dev->priv = ts; 400 401 return 0; 402 403 fail: 404 input_free_device(idev); 405 kfree(ts); 406 return err; 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