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 #include <linux/mfd/ucb1x00.h> 34 35 #include <mach/dma.h> 36 #include <mach/collie.h> 37 #include <asm/mach-types.h> 38 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 adcsync:1; 51 }; 52 53 static int adcsync; 54 55 static inline void ucb1x00_ts_evt_add(struct ucb1x00_ts *ts, u16 pressure, u16 x, u16 y) 56 { 57 struct input_dev *idev = ts->idev; 58 59 input_report_abs(idev, ABS_X, x); 60 input_report_abs(idev, ABS_Y, y); 61 input_report_abs(idev, ABS_PRESSURE, pressure); 62 input_report_key(idev, BTN_TOUCH, 1); 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_report_key(idev, BTN_TOUCH, 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 DECLARE_WAITQUEUE(wait, current); 209 bool frozen, ignore = false; 210 int valid = 0; 211 212 set_freezable(); 213 add_wait_queue(&ts->irq_wait, &wait); 214 while (!kthread_freezable_should_stop(&frozen)) { 215 unsigned int x, y, p; 216 signed long timeout; 217 218 if (frozen) 219 ignore = true; 220 221 ucb1x00_adc_enable(ts->ucb); 222 223 x = ucb1x00_ts_read_xpos(ts); 224 y = ucb1x00_ts_read_ypos(ts); 225 p = ucb1x00_ts_read_pressure(ts); 226 227 /* 228 * Switch back to interrupt mode. 229 */ 230 ucb1x00_ts_mode_int(ts); 231 ucb1x00_adc_disable(ts->ucb); 232 233 msleep(10); 234 235 ucb1x00_enable(ts->ucb); 236 237 238 if (ucb1x00_ts_pen_down(ts)) { 239 set_current_state(TASK_INTERRUPTIBLE); 240 241 ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, machine_is_collie() ? UCB_RISING : UCB_FALLING); 242 ucb1x00_disable(ts->ucb); 243 244 /* 245 * If we spat out a valid sample set last time, 246 * spit out a "pen off" sample here. 247 */ 248 if (valid) { 249 ucb1x00_ts_event_release(ts); 250 valid = 0; 251 } 252 253 timeout = MAX_SCHEDULE_TIMEOUT; 254 } else { 255 ucb1x00_disable(ts->ucb); 256 257 /* 258 * Filtering is policy. Policy belongs in user 259 * space. We therefore leave it to user space 260 * to do any filtering they please. 261 */ 262 if (!ignore) { 263 ucb1x00_ts_evt_add(ts, p, x, y); 264 valid = 1; 265 } 266 267 set_current_state(TASK_INTERRUPTIBLE); 268 timeout = HZ / 100; 269 } 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 } 341 342 343 /* 344 * Initialisation. 345 */ 346 static int ucb1x00_ts_add(struct ucb1x00_dev *dev) 347 { 348 struct ucb1x00_ts *ts; 349 struct input_dev *idev; 350 int err; 351 352 ts = kzalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL); 353 idev = input_allocate_device(); 354 if (!ts || !idev) { 355 err = -ENOMEM; 356 goto fail; 357 } 358 359 ts->ucb = dev->ucb; 360 ts->idev = idev; 361 ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC; 362 363 idev->name = "Touchscreen panel"; 364 idev->id.product = ts->ucb->id; 365 idev->open = ucb1x00_ts_open; 366 idev->close = ucb1x00_ts_close; 367 368 idev->evbit[0] = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY); 369 idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 370 371 input_set_drvdata(idev, ts); 372 373 ucb1x00_adc_enable(ts->ucb); 374 ts->x_res = ucb1x00_ts_read_xres(ts); 375 ts->y_res = ucb1x00_ts_read_yres(ts); 376 ucb1x00_adc_disable(ts->ucb); 377 378 input_set_abs_params(idev, ABS_X, 0, ts->x_res, 0, 0); 379 input_set_abs_params(idev, ABS_Y, 0, ts->y_res, 0, 0); 380 input_set_abs_params(idev, ABS_PRESSURE, 0, 0, 0, 0); 381 382 err = input_register_device(idev); 383 if (err) 384 goto fail; 385 386 dev->priv = ts; 387 388 return 0; 389 390 fail: 391 input_free_device(idev); 392 kfree(ts); 393 return err; 394 } 395 396 static void ucb1x00_ts_remove(struct ucb1x00_dev *dev) 397 { 398 struct ucb1x00_ts *ts = dev->priv; 399 400 input_unregister_device(ts->idev); 401 kfree(ts); 402 } 403 404 static struct ucb1x00_driver ucb1x00_ts_driver = { 405 .add = ucb1x00_ts_add, 406 .remove = ucb1x00_ts_remove, 407 }; 408 409 static int __init ucb1x00_ts_init(void) 410 { 411 return ucb1x00_register_driver(&ucb1x00_ts_driver); 412 } 413 414 static void __exit ucb1x00_ts_exit(void) 415 { 416 ucb1x00_unregister_driver(&ucb1x00_ts_driver); 417 } 418 419 module_param(adcsync, int, 0444); 420 module_init(ucb1x00_ts_init); 421 module_exit(ucb1x00_ts_exit); 422 423 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); 424 MODULE_DESCRIPTION("UCB1x00 touchscreen driver"); 425 MODULE_LICENSE("GPL"); 426