Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 1 | /* |
Pavel Machek | 5437775 | 2005-09-11 10:28:00 +0100 | [diff] [blame] | 2 | * Touchscreen driver for UCB1x00-based touchscreens |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 3 | * |
| 4 | * Copyright (C) 2001 Russell King, All Rights Reserved. |
Pavel Machek | 5437775 | 2005-09-11 10:28:00 +0100 | [diff] [blame] | 5 | * Copyright (C) 2005 Pavel Machek |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 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/config.h> |
| 21 | #include <linux/module.h> |
| 22 | #include <linux/moduleparam.h> |
| 23 | #include <linux/init.h> |
| 24 | #include <linux/smp.h> |
| 25 | #include <linux/smp_lock.h> |
| 26 | #include <linux/sched.h> |
| 27 | #include <linux/completion.h> |
| 28 | #include <linux/delay.h> |
| 29 | #include <linux/string.h> |
| 30 | #include <linux/input.h> |
| 31 | #include <linux/device.h> |
| 32 | #include <linux/suspend.h> |
| 33 | #include <linux/slab.h> |
Pavel Machek | 5437775 | 2005-09-11 10:28:00 +0100 | [diff] [blame] | 34 | #include <linux/kthread.h> |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 35 | |
| 36 | #include <asm/dma.h> |
| 37 | #include <asm/semaphore.h> |
| 38 | |
| 39 | #include "ucb1x00.h" |
| 40 | |
| 41 | |
| 42 | struct ucb1x00_ts { |
Dmitry Torokhov | bd62266 | 2005-09-15 02:01:48 -0500 | [diff] [blame] | 43 | struct input_dev *idev; |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 44 | struct ucb1x00 *ucb; |
| 45 | |
| 46 | wait_queue_head_t irq_wait; |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 47 | struct task_struct *rtask; |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 48 | u16 x_res; |
| 49 | u16 y_res; |
| 50 | |
Russell King | 6b9ea42 | 2005-09-24 10:24:37 +0100 | [diff] [blame] | 51 | unsigned int restart:1; |
| 52 | unsigned int adcsync:1; |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 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 | { |
Dmitry Torokhov | bd62266 | 2005-09-15 02:01:48 -0500 | [diff] [blame] | 59 | input_report_abs(ts->idev, ABS_X, x); |
| 60 | input_report_abs(ts->idev, ABS_Y, y); |
| 61 | input_report_abs(ts->idev, ABS_PRESSURE, pressure); |
| 62 | input_sync(ts->idev); |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 63 | } |
| 64 | |
| 65 | static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts) |
| 66 | { |
Dmitry Torokhov | bd62266 | 2005-09-15 02:01:48 -0500 | [diff] [blame] | 67 | input_report_abs(ts->idev, ABS_PRESSURE, 0); |
| 68 | input_sync(ts->idev); |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 69 | } |
| 70 | |
| 71 | /* |
| 72 | * Switch to interrupt mode. |
| 73 | */ |
| 74 | static inline void ucb1x00_ts_mode_int(struct ucb1x00_ts *ts) |
| 75 | { |
| 76 | ucb1x00_reg_write(ts->ucb, UCB_TS_CR, |
| 77 | UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW | |
| 78 | UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND | |
| 79 | UCB_TS_CR_MODE_INT); |
| 80 | } |
| 81 | |
| 82 | /* |
| 83 | * Switch to pressure mode, and read pressure. We don't need to wait |
| 84 | * here, since both plates are being driven. |
| 85 | */ |
| 86 | static inline unsigned int ucb1x00_ts_read_pressure(struct ucb1x00_ts *ts) |
| 87 | { |
| 88 | ucb1x00_reg_write(ts->ucb, UCB_TS_CR, |
| 89 | UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW | |
| 90 | UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND | |
| 91 | UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); |
| 92 | |
| 93 | return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync); |
| 94 | } |
| 95 | |
| 96 | /* |
| 97 | * Switch to X position mode and measure Y plate. We switch the plate |
| 98 | * configuration in pressure mode, then switch to position mode. This |
| 99 | * gives a faster response time. Even so, we need to wait about 55us |
| 100 | * for things to stabilise. |
| 101 | */ |
| 102 | static inline unsigned int ucb1x00_ts_read_xpos(struct ucb1x00_ts *ts) |
| 103 | { |
| 104 | ucb1x00_reg_write(ts->ucb, UCB_TS_CR, |
| 105 | UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | |
| 106 | UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); |
| 107 | ucb1x00_reg_write(ts->ucb, UCB_TS_CR, |
| 108 | UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | |
| 109 | UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); |
| 110 | ucb1x00_reg_write(ts->ucb, UCB_TS_CR, |
| 111 | UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | |
| 112 | UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA); |
| 113 | |
| 114 | udelay(55); |
| 115 | |
| 116 | return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync); |
| 117 | } |
| 118 | |
| 119 | /* |
| 120 | * Switch to Y position mode and measure X plate. We switch the plate |
| 121 | * configuration in pressure mode, then switch to position mode. This |
| 122 | * gives a faster response time. Even so, we need to wait about 55us |
| 123 | * for things to stabilise. |
| 124 | */ |
| 125 | static inline unsigned int ucb1x00_ts_read_ypos(struct ucb1x00_ts *ts) |
| 126 | { |
| 127 | ucb1x00_reg_write(ts->ucb, UCB_TS_CR, |
| 128 | UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | |
| 129 | UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); |
| 130 | ucb1x00_reg_write(ts->ucb, UCB_TS_CR, |
| 131 | UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | |
| 132 | UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); |
| 133 | ucb1x00_reg_write(ts->ucb, UCB_TS_CR, |
| 134 | UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | |
| 135 | UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA); |
| 136 | |
| 137 | udelay(55); |
| 138 | |
| 139 | return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPX, ts->adcsync); |
| 140 | } |
| 141 | |
| 142 | /* |
| 143 | * Switch to X plate resistance mode. Set MX to ground, PX to |
| 144 | * supply. Measure current. |
| 145 | */ |
| 146 | static inline unsigned int ucb1x00_ts_read_xres(struct ucb1x00_ts *ts) |
| 147 | { |
| 148 | ucb1x00_reg_write(ts->ucb, UCB_TS_CR, |
| 149 | UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | |
| 150 | UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); |
| 151 | return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync); |
| 152 | } |
| 153 | |
| 154 | /* |
| 155 | * Switch to Y plate resistance mode. Set MY to ground, PY to |
| 156 | * supply. Measure current. |
| 157 | */ |
| 158 | static inline unsigned int ucb1x00_ts_read_yres(struct ucb1x00_ts *ts) |
| 159 | { |
| 160 | ucb1x00_reg_write(ts->ucb, UCB_TS_CR, |
| 161 | UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | |
| 162 | UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); |
| 163 | return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync); |
| 164 | } |
| 165 | |
| 166 | /* |
| 167 | * This is a RT kernel thread that handles the ADC accesses |
| 168 | * (mainly so we can use semaphores in the UCB1200 core code |
| 169 | * to serialise accesses to the ADC). |
| 170 | */ |
| 171 | static int ucb1x00_thread(void *_ts) |
| 172 | { |
| 173 | struct ucb1x00_ts *ts = _ts; |
| 174 | struct task_struct *tsk = current; |
| 175 | DECLARE_WAITQUEUE(wait, tsk); |
| 176 | int valid; |
| 177 | |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 178 | /* |
| 179 | * We could run as a real-time thread. However, thus far |
| 180 | * this doesn't seem to be necessary. |
| 181 | */ |
| 182 | // tsk->policy = SCHED_FIFO; |
| 183 | // tsk->rt_priority = 1; |
| 184 | |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 185 | valid = 0; |
| 186 | |
| 187 | add_wait_queue(&ts->irq_wait, &wait); |
Pavel Machek | 5437775 | 2005-09-11 10:28:00 +0100 | [diff] [blame] | 188 | while (!kthread_should_stop()) { |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 189 | unsigned int x, y, p, val; |
| 190 | signed long timeout; |
| 191 | |
| 192 | ts->restart = 0; |
| 193 | |
| 194 | ucb1x00_adc_enable(ts->ucb); |
| 195 | |
| 196 | x = ucb1x00_ts_read_xpos(ts); |
| 197 | y = ucb1x00_ts_read_ypos(ts); |
| 198 | p = ucb1x00_ts_read_pressure(ts); |
| 199 | |
| 200 | /* |
| 201 | * Switch back to interrupt mode. |
| 202 | */ |
| 203 | ucb1x00_ts_mode_int(ts); |
| 204 | ucb1x00_adc_disable(ts->ucb); |
| 205 | |
Pavel Machek | 5437775 | 2005-09-11 10:28:00 +0100 | [diff] [blame] | 206 | msleep(10); |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 207 | |
| 208 | ucb1x00_enable(ts->ucb); |
| 209 | val = ucb1x00_reg_read(ts->ucb, UCB_TS_CR); |
| 210 | |
| 211 | if (val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW)) { |
| 212 | set_task_state(tsk, TASK_INTERRUPTIBLE); |
| 213 | |
| 214 | ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING); |
| 215 | ucb1x00_disable(ts->ucb); |
| 216 | |
| 217 | /* |
| 218 | * If we spat out a valid sample set last time, |
| 219 | * spit out a "pen off" sample here. |
| 220 | */ |
| 221 | if (valid) { |
| 222 | ucb1x00_ts_event_release(ts); |
| 223 | valid = 0; |
| 224 | } |
| 225 | |
| 226 | timeout = MAX_SCHEDULE_TIMEOUT; |
| 227 | } else { |
| 228 | ucb1x00_disable(ts->ucb); |
| 229 | |
| 230 | /* |
| 231 | * Filtering is policy. Policy belongs in user |
| 232 | * space. We therefore leave it to user space |
| 233 | * to do any filtering they please. |
| 234 | */ |
| 235 | if (!ts->restart) { |
| 236 | ucb1x00_ts_evt_add(ts, p, x, y); |
| 237 | valid = 1; |
| 238 | } |
| 239 | |
| 240 | set_task_state(tsk, TASK_INTERRUPTIBLE); |
| 241 | timeout = HZ / 100; |
| 242 | } |
| 243 | |
| 244 | try_to_freeze(); |
| 245 | |
| 246 | schedule_timeout(timeout); |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 247 | } |
| 248 | |
| 249 | remove_wait_queue(&ts->irq_wait, &wait); |
| 250 | |
| 251 | ts->rtask = NULL; |
Pavel Machek | 5437775 | 2005-09-11 10:28:00 +0100 | [diff] [blame] | 252 | return 0; |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 253 | } |
| 254 | |
| 255 | /* |
| 256 | * We only detect touch screen _touches_ with this interrupt |
| 257 | * handler, and even then we just schedule our task. |
| 258 | */ |
| 259 | static void ucb1x00_ts_irq(int idx, void *id) |
| 260 | { |
| 261 | struct ucb1x00_ts *ts = id; |
| 262 | ucb1x00_disable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING); |
| 263 | wake_up(&ts->irq_wait); |
| 264 | } |
| 265 | |
| 266 | static int ucb1x00_ts_open(struct input_dev *idev) |
| 267 | { |
| 268 | struct ucb1x00_ts *ts = (struct ucb1x00_ts *)idev; |
| 269 | int ret = 0; |
| 270 | |
Pavel Machek | 5437775 | 2005-09-11 10:28:00 +0100 | [diff] [blame] | 271 | BUG_ON(ts->rtask); |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 272 | |
| 273 | init_waitqueue_head(&ts->irq_wait); |
| 274 | ret = ucb1x00_hook_irq(ts->ucb, UCB_IRQ_TSPX, ucb1x00_ts_irq, ts); |
| 275 | if (ret < 0) |
| 276 | goto out; |
| 277 | |
| 278 | /* |
| 279 | * If we do this at all, we should allow the user to |
| 280 | * measure and read the X and Y resistance at any time. |
| 281 | */ |
| 282 | ucb1x00_adc_enable(ts->ucb); |
| 283 | ts->x_res = ucb1x00_ts_read_xres(ts); |
| 284 | ts->y_res = ucb1x00_ts_read_yres(ts); |
| 285 | ucb1x00_adc_disable(ts->ucb); |
| 286 | |
Pavel Machek | 5437775 | 2005-09-11 10:28:00 +0100 | [diff] [blame] | 287 | ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd"); |
| 288 | if (!IS_ERR(ts->rtask)) { |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 289 | ret = 0; |
| 290 | } else { |
| 291 | ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts); |
Pavel Machek | 5437775 | 2005-09-11 10:28:00 +0100 | [diff] [blame] | 292 | ts->rtask = NULL; |
| 293 | ret = -EFAULT; |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 294 | } |
| 295 | |
| 296 | out: |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 297 | return ret; |
| 298 | } |
| 299 | |
| 300 | /* |
| 301 | * Release touchscreen resources. Disable IRQs. |
| 302 | */ |
| 303 | static void ucb1x00_ts_close(struct input_dev *idev) |
| 304 | { |
| 305 | struct ucb1x00_ts *ts = (struct ucb1x00_ts *)idev; |
| 306 | |
Pavel Machek | 5437775 | 2005-09-11 10:28:00 +0100 | [diff] [blame] | 307 | if (ts->rtask) |
| 308 | kthread_stop(ts->rtask); |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 309 | |
Pavel Machek | 5437775 | 2005-09-11 10:28:00 +0100 | [diff] [blame] | 310 | ucb1x00_enable(ts->ucb); |
| 311 | ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts); |
| 312 | ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0); |
| 313 | ucb1x00_disable(ts->ucb); |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 314 | } |
| 315 | |
| 316 | #ifdef CONFIG_PM |
| 317 | static int ucb1x00_ts_resume(struct ucb1x00_dev *dev) |
| 318 | { |
| 319 | struct ucb1x00_ts *ts = dev->priv; |
| 320 | |
| 321 | if (ts->rtask != NULL) { |
| 322 | /* |
| 323 | * Restart the TS thread to ensure the |
| 324 | * TS interrupt mode is set up again |
| 325 | * after sleep. |
| 326 | */ |
| 327 | ts->restart = 1; |
| 328 | wake_up(&ts->irq_wait); |
| 329 | } |
| 330 | return 0; |
| 331 | } |
| 332 | #else |
| 333 | #define ucb1x00_ts_resume NULL |
| 334 | #endif |
| 335 | |
| 336 | |
| 337 | /* |
| 338 | * Initialisation. |
| 339 | */ |
| 340 | static int ucb1x00_ts_add(struct ucb1x00_dev *dev) |
| 341 | { |
| 342 | struct ucb1x00_ts *ts; |
| 343 | |
Dmitry Torokhov | bd62266 | 2005-09-15 02:01:48 -0500 | [diff] [blame] | 344 | ts = kzalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL); |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 345 | if (!ts) |
| 346 | return -ENOMEM; |
| 347 | |
Dmitry Torokhov | bd62266 | 2005-09-15 02:01:48 -0500 | [diff] [blame] | 348 | ts->idev = input_allocate_device(); |
| 349 | if (!ts->idev) { |
| 350 | kfree(ts); |
| 351 | return -ENOMEM; |
| 352 | } |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 353 | |
| 354 | ts->ucb = dev->ucb; |
| 355 | ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC; |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 356 | |
Dmitry Torokhov | bd62266 | 2005-09-15 02:01:48 -0500 | [diff] [blame] | 357 | ts->idev->name = "Touchscreen panel"; |
| 358 | ts->idev->id.product = ts->ucb->id; |
| 359 | ts->idev->open = ucb1x00_ts_open; |
| 360 | ts->idev->close = ucb1x00_ts_close; |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 361 | |
Dmitry Torokhov | bd62266 | 2005-09-15 02:01:48 -0500 | [diff] [blame] | 362 | __set_bit(EV_ABS, ts->idev->evbit); |
| 363 | __set_bit(ABS_X, ts->idev->absbit); |
| 364 | __set_bit(ABS_Y, ts->idev->absbit); |
| 365 | __set_bit(ABS_PRESSURE, ts->idev->absbit); |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 366 | |
Dmitry Torokhov | bd62266 | 2005-09-15 02:01:48 -0500 | [diff] [blame] | 367 | input_register_device(ts->idev); |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 368 | |
| 369 | dev->priv = ts; |
| 370 | |
| 371 | return 0; |
| 372 | } |
| 373 | |
| 374 | static void ucb1x00_ts_remove(struct ucb1x00_dev *dev) |
| 375 | { |
| 376 | struct ucb1x00_ts *ts = dev->priv; |
Dmitry Torokhov | bd62266 | 2005-09-15 02:01:48 -0500 | [diff] [blame] | 377 | |
| 378 | input_unregister_device(ts->idev); |
Russell King | acb4543 | 2005-09-11 10:26:57 +0100 | [diff] [blame] | 379 | kfree(ts); |
| 380 | } |
| 381 | |
| 382 | static struct ucb1x00_driver ucb1x00_ts_driver = { |
| 383 | .add = ucb1x00_ts_add, |
| 384 | .remove = ucb1x00_ts_remove, |
| 385 | .resume = ucb1x00_ts_resume, |
| 386 | }; |
| 387 | |
| 388 | static int __init ucb1x00_ts_init(void) |
| 389 | { |
| 390 | return ucb1x00_register_driver(&ucb1x00_ts_driver); |
| 391 | } |
| 392 | |
| 393 | static void __exit ucb1x00_ts_exit(void) |
| 394 | { |
| 395 | ucb1x00_unregister_driver(&ucb1x00_ts_driver); |
| 396 | } |
| 397 | |
| 398 | module_param(adcsync, int, 0444); |
| 399 | module_init(ucb1x00_ts_init); |
| 400 | module_exit(ucb1x00_ts_exit); |
| 401 | |
| 402 | MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); |
| 403 | MODULE_DESCRIPTION("UCB1x00 touchscreen driver"); |
| 404 | MODULE_LICENSE("GPL"); |