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 = 0; 211 212 set_freezable(); 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 = input_get_drvdata(idev); 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 = input_get_drvdata(idev); 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->name = "Touchscreen panel"; 385 idev->id.product = ts->ucb->id; 386 idev->open = ucb1x00_ts_open; 387 idev->close = ucb1x00_ts_close; 388 389 __set_bit(EV_ABS, idev->evbit); 390 __set_bit(ABS_X, idev->absbit); 391 __set_bit(ABS_Y, idev->absbit); 392 __set_bit(ABS_PRESSURE, idev->absbit); 393 394 input_set_drvdata(idev, ts); 395 396 err = input_register_device(idev); 397 if (err) 398 goto fail; 399 400 dev->priv = ts; 401 402 return 0; 403 404 fail: 405 input_free_device(idev); 406 kfree(ts); 407 return err; 408 } 409 410 static void ucb1x00_ts_remove(struct ucb1x00_dev *dev) 411 { 412 struct ucb1x00_ts *ts = dev->priv; 413 414 input_unregister_device(ts->idev); 415 kfree(ts); 416 } 417 418 static struct ucb1x00_driver ucb1x00_ts_driver = { 419 .add = ucb1x00_ts_add, 420 .remove = ucb1x00_ts_remove, 421 .resume = ucb1x00_ts_resume, 422 }; 423 424 static int __init ucb1x00_ts_init(void) 425 { 426 return ucb1x00_register_driver(&ucb1x00_ts_driver); 427 } 428 429 static void __exit ucb1x00_ts_exit(void) 430 { 431 ucb1x00_unregister_driver(&ucb1x00_ts_driver); 432 } 433 434 module_param(adcsync, int, 0444); 435 module_init(ucb1x00_ts_init); 436 module_exit(ucb1x00_ts_exit); 437 438 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); 439 MODULE_DESCRIPTION("UCB1x00 touchscreen driver"); 440 MODULE_LICENSE("GPL"); 441