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/arch/collie.h> 36 #include <asm/mach-types.h> 37 38 #include "ucb1x00.h" 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 struct task_struct *tsk = current; 208 DECLARE_WAITQUEUE(wait, tsk); 209 int valid = 0; 210 211 set_freezable(); 212 add_wait_queue(&ts->irq_wait, &wait); 213 while (!kthread_should_stop()) { 214 unsigned int x, y, p; 215 signed long timeout; 216 217 ts->restart = 0; 218 219 ucb1x00_adc_enable(ts->ucb); 220 221 x = ucb1x00_ts_read_xpos(ts); 222 y = ucb1x00_ts_read_ypos(ts); 223 p = ucb1x00_ts_read_pressure(ts); 224 225 /* 226 * Switch back to interrupt mode. 227 */ 228 ucb1x00_ts_mode_int(ts); 229 ucb1x00_adc_disable(ts->ucb); 230 231 msleep(10); 232 233 ucb1x00_enable(ts->ucb); 234 235 236 if (ucb1x00_ts_pen_down(ts)) { 237 set_task_state(tsk, TASK_INTERRUPTIBLE); 238 239 ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, machine_is_collie() ? UCB_RISING : UCB_FALLING); 240 ucb1x00_disable(ts->ucb); 241 242 /* 243 * If we spat out a valid sample set last time, 244 * spit out a "pen off" sample here. 245 */ 246 if (valid) { 247 ucb1x00_ts_event_release(ts); 248 valid = 0; 249 } 250 251 timeout = MAX_SCHEDULE_TIMEOUT; 252 } else { 253 ucb1x00_disable(ts->ucb); 254 255 /* 256 * Filtering is policy. Policy belongs in user 257 * space. We therefore leave it to user space 258 * to do any filtering they please. 259 */ 260 if (!ts->restart) { 261 ucb1x00_ts_evt_add(ts, p, x, y); 262 valid = 1; 263 } 264 265 set_task_state(tsk, TASK_INTERRUPTIBLE); 266 timeout = HZ / 100; 267 } 268 269 try_to_freeze(); 270 271 schedule_timeout(timeout); 272 } 273 274 remove_wait_queue(&ts->irq_wait, &wait); 275 276 ts->rtask = NULL; 277 return 0; 278 } 279 280 /* 281 * We only detect touch screen _touches_ with this interrupt 282 * handler, and even then we just schedule our task. 283 */ 284 static void ucb1x00_ts_irq(int idx, void *id) 285 { 286 struct ucb1x00_ts *ts = id; 287 288 ucb1x00_disable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING); 289 wake_up(&ts->irq_wait); 290 } 291 292 static int ucb1x00_ts_open(struct input_dev *idev) 293 { 294 struct ucb1x00_ts *ts = input_get_drvdata(idev); 295 int ret = 0; 296 297 BUG_ON(ts->rtask); 298 299 init_waitqueue_head(&ts->irq_wait); 300 ret = ucb1x00_hook_irq(ts->ucb, UCB_IRQ_TSPX, ucb1x00_ts_irq, ts); 301 if (ret < 0) 302 goto out; 303 304 /* 305 * If we do this at all, we should allow the user to 306 * measure and read the X and Y resistance at any time. 307 */ 308 ucb1x00_adc_enable(ts->ucb); 309 ts->x_res = ucb1x00_ts_read_xres(ts); 310 ts->y_res = ucb1x00_ts_read_yres(ts); 311 ucb1x00_adc_disable(ts->ucb); 312 313 ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd"); 314 if (!IS_ERR(ts->rtask)) { 315 ret = 0; 316 } else { 317 ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts); 318 ts->rtask = NULL; 319 ret = -EFAULT; 320 } 321 322 out: 323 return ret; 324 } 325 326 /* 327 * Release touchscreen resources. Disable IRQs. 328 */ 329 static void ucb1x00_ts_close(struct input_dev *idev) 330 { 331 struct ucb1x00_ts *ts = input_get_drvdata(idev); 332 333 if (ts->rtask) 334 kthread_stop(ts->rtask); 335 336 ucb1x00_enable(ts->ucb); 337 ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts); 338 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0); 339 ucb1x00_disable(ts->ucb); 340 } 341 342 #ifdef CONFIG_PM 343 static int ucb1x00_ts_resume(struct ucb1x00_dev *dev) 344 { 345 struct ucb1x00_ts *ts = dev->priv; 346 347 if (ts->rtask != NULL) { 348 /* 349 * Restart the TS thread to ensure the 350 * TS interrupt mode is set up again 351 * after sleep. 352 */ 353 ts->restart = 1; 354 wake_up(&ts->irq_wait); 355 } 356 return 0; 357 } 358 #else 359 #define ucb1x00_ts_resume NULL 360 #endif 361 362 363 /* 364 * Initialisation. 365 */ 366 static int ucb1x00_ts_add(struct ucb1x00_dev *dev) 367 { 368 struct ucb1x00_ts *ts; 369 struct input_dev *idev; 370 int err; 371 372 ts = kzalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL); 373 idev = input_allocate_device(); 374 if (!ts || !idev) { 375 err = -ENOMEM; 376 goto fail; 377 } 378 379 ts->ucb = dev->ucb; 380 ts->idev = idev; 381 ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC; 382 383 idev->name = "Touchscreen panel"; 384 idev->id.product = ts->ucb->id; 385 idev->open = ucb1x00_ts_open; 386 idev->close = ucb1x00_ts_close; 387 388 __set_bit(EV_ABS, idev->evbit); 389 __set_bit(ABS_X, idev->absbit); 390 __set_bit(ABS_Y, idev->absbit); 391 __set_bit(ABS_PRESSURE, idev->absbit); 392 393 input_set_drvdata(idev, ts); 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