1acb45439SRussell King /* 25437775eSPavel Machek * Touchscreen driver for UCB1x00-based touchscreens 3acb45439SRussell King * 4acb45439SRussell King * Copyright (C) 2001 Russell King, All Rights Reserved. 55437775eSPavel Machek * Copyright (C) 2005 Pavel Machek 6acb45439SRussell King * 7acb45439SRussell King * This program is free software; you can redistribute it and/or modify 8acb45439SRussell King * it under the terms of the GNU General Public License version 2 as 9acb45439SRussell King * published by the Free Software Foundation. 10acb45439SRussell King * 11acb45439SRussell King * 21-Jan-2002 <jco@ict.es> : 12acb45439SRussell King * 13acb45439SRussell King * Added support for synchronous A/D mode. This mode is useful to 14acb45439SRussell King * avoid noise induced in the touchpanel by the LCD, provided that 15acb45439SRussell King * the UCB1x00 has a valid LCD sync signal routed to its ADCSYNC pin. 16acb45439SRussell King * It is important to note that the signal connected to the ADCSYNC 17acb45439SRussell King * pin should provide pulses even when the LCD is blanked, otherwise 18acb45439SRussell King * a pen touch needed to unblank the LCD will never be read. 19acb45439SRussell King */ 20acb45439SRussell King #include <linux/config.h> 21acb45439SRussell King #include <linux/module.h> 22acb45439SRussell King #include <linux/moduleparam.h> 23acb45439SRussell King #include <linux/init.h> 24acb45439SRussell King #include <linux/smp.h> 25acb45439SRussell King #include <linux/smp_lock.h> 26acb45439SRussell King #include <linux/sched.h> 27acb45439SRussell King #include <linux/completion.h> 28acb45439SRussell King #include <linux/delay.h> 29acb45439SRussell King #include <linux/string.h> 30acb45439SRussell King #include <linux/input.h> 31acb45439SRussell King #include <linux/device.h> 32acb45439SRussell King #include <linux/suspend.h> 33acb45439SRussell King #include <linux/slab.h> 345437775eSPavel Machek #include <linux/kthread.h> 35acb45439SRussell King 36acb45439SRussell King #include <asm/dma.h> 37acb45439SRussell King #include <asm/semaphore.h> 38acb45439SRussell King 39acb45439SRussell King #include "ucb1x00.h" 40acb45439SRussell King 41acb45439SRussell King 42acb45439SRussell King struct ucb1x00_ts { 43bd622663SDmitry Torokhov struct input_dev *idev; 44acb45439SRussell King struct ucb1x00 *ucb; 45acb45439SRussell King 46acb45439SRussell King wait_queue_head_t irq_wait; 47acb45439SRussell King struct task_struct *rtask; 48acb45439SRussell King u16 x_res; 49acb45439SRussell King u16 y_res; 50acb45439SRussell King 516b9ea421SRussell King unsigned int restart:1; 526b9ea421SRussell King unsigned int adcsync:1; 53acb45439SRussell King }; 54acb45439SRussell King 55acb45439SRussell King static int adcsync; 56acb45439SRussell King 57acb45439SRussell King static inline void ucb1x00_ts_evt_add(struct ucb1x00_ts *ts, u16 pressure, u16 x, u16 y) 58acb45439SRussell King { 59bd622663SDmitry Torokhov input_report_abs(ts->idev, ABS_X, x); 60bd622663SDmitry Torokhov input_report_abs(ts->idev, ABS_Y, y); 61bd622663SDmitry Torokhov input_report_abs(ts->idev, ABS_PRESSURE, pressure); 62bd622663SDmitry Torokhov input_sync(ts->idev); 63acb45439SRussell King } 64acb45439SRussell King 65acb45439SRussell King static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts) 66acb45439SRussell King { 67bd622663SDmitry Torokhov input_report_abs(ts->idev, ABS_PRESSURE, 0); 68bd622663SDmitry Torokhov input_sync(ts->idev); 69acb45439SRussell King } 70acb45439SRussell King 71acb45439SRussell King /* 72acb45439SRussell King * Switch to interrupt mode. 73acb45439SRussell King */ 74acb45439SRussell King static inline void ucb1x00_ts_mode_int(struct ucb1x00_ts *ts) 75acb45439SRussell King { 76acb45439SRussell King ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 77acb45439SRussell King UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW | 78acb45439SRussell King UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND | 79acb45439SRussell King UCB_TS_CR_MODE_INT); 80acb45439SRussell King } 81acb45439SRussell King 82acb45439SRussell King /* 83acb45439SRussell King * Switch to pressure mode, and read pressure. We don't need to wait 84acb45439SRussell King * here, since both plates are being driven. 85acb45439SRussell King */ 86acb45439SRussell King static inline unsigned int ucb1x00_ts_read_pressure(struct ucb1x00_ts *ts) 87acb45439SRussell King { 88acb45439SRussell King ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 89acb45439SRussell King UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW | 90acb45439SRussell King UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND | 91acb45439SRussell King UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 92acb45439SRussell King 93acb45439SRussell King return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync); 94acb45439SRussell King } 95acb45439SRussell King 96acb45439SRussell King /* 97acb45439SRussell King * Switch to X position mode and measure Y plate. We switch the plate 98acb45439SRussell King * configuration in pressure mode, then switch to position mode. This 99acb45439SRussell King * gives a faster response time. Even so, we need to wait about 55us 100acb45439SRussell King * for things to stabilise. 101acb45439SRussell King */ 102acb45439SRussell King static inline unsigned int ucb1x00_ts_read_xpos(struct ucb1x00_ts *ts) 103acb45439SRussell King { 104acb45439SRussell King ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 105acb45439SRussell King UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | 106acb45439SRussell King UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 107acb45439SRussell King ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 108acb45439SRussell King UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | 109acb45439SRussell King UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 110acb45439SRussell King ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 111acb45439SRussell King UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | 112acb45439SRussell King UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA); 113acb45439SRussell King 114acb45439SRussell King udelay(55); 115acb45439SRussell King 116acb45439SRussell King return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync); 117acb45439SRussell King } 118acb45439SRussell King 119acb45439SRussell King /* 120acb45439SRussell King * Switch to Y position mode and measure X plate. We switch the plate 121acb45439SRussell King * configuration in pressure mode, then switch to position mode. This 122acb45439SRussell King * gives a faster response time. Even so, we need to wait about 55us 123acb45439SRussell King * for things to stabilise. 124acb45439SRussell King */ 125acb45439SRussell King static inline unsigned int ucb1x00_ts_read_ypos(struct ucb1x00_ts *ts) 126acb45439SRussell King { 127acb45439SRussell King ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 128acb45439SRussell King UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | 129acb45439SRussell King UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 130acb45439SRussell King ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 131acb45439SRussell King UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | 132acb45439SRussell King UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 133acb45439SRussell King ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 134acb45439SRussell King UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | 135acb45439SRussell King UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA); 136acb45439SRussell King 137acb45439SRussell King udelay(55); 138acb45439SRussell King 139acb45439SRussell King return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPX, ts->adcsync); 140acb45439SRussell King } 141acb45439SRussell King 142acb45439SRussell King /* 143acb45439SRussell King * Switch to X plate resistance mode. Set MX to ground, PX to 144acb45439SRussell King * supply. Measure current. 145acb45439SRussell King */ 146acb45439SRussell King static inline unsigned int ucb1x00_ts_read_xres(struct ucb1x00_ts *ts) 147acb45439SRussell King { 148acb45439SRussell King ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 149acb45439SRussell King UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | 150acb45439SRussell King UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 151acb45439SRussell King return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync); 152acb45439SRussell King } 153acb45439SRussell King 154acb45439SRussell King /* 155acb45439SRussell King * Switch to Y plate resistance mode. Set MY to ground, PY to 156acb45439SRussell King * supply. Measure current. 157acb45439SRussell King */ 158acb45439SRussell King static inline unsigned int ucb1x00_ts_read_yres(struct ucb1x00_ts *ts) 159acb45439SRussell King { 160acb45439SRussell King ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 161acb45439SRussell King UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | 162acb45439SRussell King UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); 163acb45439SRussell King return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync); 164acb45439SRussell King } 165acb45439SRussell King 166acb45439SRussell King /* 167acb45439SRussell King * This is a RT kernel thread that handles the ADC accesses 168acb45439SRussell King * (mainly so we can use semaphores in the UCB1200 core code 169acb45439SRussell King * to serialise accesses to the ADC). 170acb45439SRussell King */ 171acb45439SRussell King static int ucb1x00_thread(void *_ts) 172acb45439SRussell King { 173acb45439SRussell King struct ucb1x00_ts *ts = _ts; 174acb45439SRussell King struct task_struct *tsk = current; 175acb45439SRussell King DECLARE_WAITQUEUE(wait, tsk); 176acb45439SRussell King int valid; 177acb45439SRussell King 178acb45439SRussell King /* 179acb45439SRussell King * We could run as a real-time thread. However, thus far 180acb45439SRussell King * this doesn't seem to be necessary. 181acb45439SRussell King */ 182acb45439SRussell King // tsk->policy = SCHED_FIFO; 183acb45439SRussell King // tsk->rt_priority = 1; 184acb45439SRussell King 185acb45439SRussell King valid = 0; 186acb45439SRussell King 187acb45439SRussell King add_wait_queue(&ts->irq_wait, &wait); 1885437775eSPavel Machek while (!kthread_should_stop()) { 189acb45439SRussell King unsigned int x, y, p, val; 190acb45439SRussell King signed long timeout; 191acb45439SRussell King 192acb45439SRussell King ts->restart = 0; 193acb45439SRussell King 194acb45439SRussell King ucb1x00_adc_enable(ts->ucb); 195acb45439SRussell King 196acb45439SRussell King x = ucb1x00_ts_read_xpos(ts); 197acb45439SRussell King y = ucb1x00_ts_read_ypos(ts); 198acb45439SRussell King p = ucb1x00_ts_read_pressure(ts); 199acb45439SRussell King 200acb45439SRussell King /* 201acb45439SRussell King * Switch back to interrupt mode. 202acb45439SRussell King */ 203acb45439SRussell King ucb1x00_ts_mode_int(ts); 204acb45439SRussell King ucb1x00_adc_disable(ts->ucb); 205acb45439SRussell King 2065437775eSPavel Machek msleep(10); 207acb45439SRussell King 208acb45439SRussell King ucb1x00_enable(ts->ucb); 209acb45439SRussell King val = ucb1x00_reg_read(ts->ucb, UCB_TS_CR); 210acb45439SRussell King 211acb45439SRussell King if (val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW)) { 212acb45439SRussell King set_task_state(tsk, TASK_INTERRUPTIBLE); 213acb45439SRussell King 214acb45439SRussell King ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING); 215acb45439SRussell King ucb1x00_disable(ts->ucb); 216acb45439SRussell King 217acb45439SRussell King /* 218acb45439SRussell King * If we spat out a valid sample set last time, 219acb45439SRussell King * spit out a "pen off" sample here. 220acb45439SRussell King */ 221acb45439SRussell King if (valid) { 222acb45439SRussell King ucb1x00_ts_event_release(ts); 223acb45439SRussell King valid = 0; 224acb45439SRussell King } 225acb45439SRussell King 226acb45439SRussell King timeout = MAX_SCHEDULE_TIMEOUT; 227acb45439SRussell King } else { 228acb45439SRussell King ucb1x00_disable(ts->ucb); 229acb45439SRussell King 230acb45439SRussell King /* 231acb45439SRussell King * Filtering is policy. Policy belongs in user 232acb45439SRussell King * space. We therefore leave it to user space 233acb45439SRussell King * to do any filtering they please. 234acb45439SRussell King */ 235acb45439SRussell King if (!ts->restart) { 236acb45439SRussell King ucb1x00_ts_evt_add(ts, p, x, y); 237acb45439SRussell King valid = 1; 238acb45439SRussell King } 239acb45439SRussell King 240acb45439SRussell King set_task_state(tsk, TASK_INTERRUPTIBLE); 241acb45439SRussell King timeout = HZ / 100; 242acb45439SRussell King } 243acb45439SRussell King 244acb45439SRussell King try_to_freeze(); 245acb45439SRussell King 246acb45439SRussell King schedule_timeout(timeout); 247acb45439SRussell King } 248acb45439SRussell King 249acb45439SRussell King remove_wait_queue(&ts->irq_wait, &wait); 250acb45439SRussell King 251acb45439SRussell King ts->rtask = NULL; 2525437775eSPavel Machek return 0; 253acb45439SRussell King } 254acb45439SRussell King 255acb45439SRussell King /* 256acb45439SRussell King * We only detect touch screen _touches_ with this interrupt 257acb45439SRussell King * handler, and even then we just schedule our task. 258acb45439SRussell King */ 259acb45439SRussell King static void ucb1x00_ts_irq(int idx, void *id) 260acb45439SRussell King { 261acb45439SRussell King struct ucb1x00_ts *ts = id; 262acb45439SRussell King ucb1x00_disable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING); 263acb45439SRussell King wake_up(&ts->irq_wait); 264acb45439SRussell King } 265acb45439SRussell King 266acb45439SRussell King static int ucb1x00_ts_open(struct input_dev *idev) 267acb45439SRussell King { 268acb45439SRussell King struct ucb1x00_ts *ts = (struct ucb1x00_ts *)idev; 269acb45439SRussell King int ret = 0; 270acb45439SRussell King 2715437775eSPavel Machek BUG_ON(ts->rtask); 272acb45439SRussell King 273acb45439SRussell King init_waitqueue_head(&ts->irq_wait); 274acb45439SRussell King ret = ucb1x00_hook_irq(ts->ucb, UCB_IRQ_TSPX, ucb1x00_ts_irq, ts); 275acb45439SRussell King if (ret < 0) 276acb45439SRussell King goto out; 277acb45439SRussell King 278acb45439SRussell King /* 279acb45439SRussell King * If we do this at all, we should allow the user to 280acb45439SRussell King * measure and read the X and Y resistance at any time. 281acb45439SRussell King */ 282acb45439SRussell King ucb1x00_adc_enable(ts->ucb); 283acb45439SRussell King ts->x_res = ucb1x00_ts_read_xres(ts); 284acb45439SRussell King ts->y_res = ucb1x00_ts_read_yres(ts); 285acb45439SRussell King ucb1x00_adc_disable(ts->ucb); 286acb45439SRussell King 2875437775eSPavel Machek ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd"); 2885437775eSPavel Machek if (!IS_ERR(ts->rtask)) { 289acb45439SRussell King ret = 0; 290acb45439SRussell King } else { 291acb45439SRussell King ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts); 2925437775eSPavel Machek ts->rtask = NULL; 2935437775eSPavel Machek ret = -EFAULT; 294acb45439SRussell King } 295acb45439SRussell King 296acb45439SRussell King out: 297acb45439SRussell King return ret; 298acb45439SRussell King } 299acb45439SRussell King 300acb45439SRussell King /* 301acb45439SRussell King * Release touchscreen resources. Disable IRQs. 302acb45439SRussell King */ 303acb45439SRussell King static void ucb1x00_ts_close(struct input_dev *idev) 304acb45439SRussell King { 305acb45439SRussell King struct ucb1x00_ts *ts = (struct ucb1x00_ts *)idev; 306acb45439SRussell King 3075437775eSPavel Machek if (ts->rtask) 3085437775eSPavel Machek kthread_stop(ts->rtask); 309acb45439SRussell King 310acb45439SRussell King ucb1x00_enable(ts->ucb); 311acb45439SRussell King ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts); 312acb45439SRussell King ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0); 313acb45439SRussell King ucb1x00_disable(ts->ucb); 314acb45439SRussell King } 315acb45439SRussell King 316acb45439SRussell King #ifdef CONFIG_PM 317acb45439SRussell King static int ucb1x00_ts_resume(struct ucb1x00_dev *dev) 318acb45439SRussell King { 319acb45439SRussell King struct ucb1x00_ts *ts = dev->priv; 320acb45439SRussell King 321acb45439SRussell King if (ts->rtask != NULL) { 322acb45439SRussell King /* 323acb45439SRussell King * Restart the TS thread to ensure the 324acb45439SRussell King * TS interrupt mode is set up again 325acb45439SRussell King * after sleep. 326acb45439SRussell King */ 327acb45439SRussell King ts->restart = 1; 328acb45439SRussell King wake_up(&ts->irq_wait); 329acb45439SRussell King } 330acb45439SRussell King return 0; 331acb45439SRussell King } 332acb45439SRussell King #else 333acb45439SRussell King #define ucb1x00_ts_resume NULL 334acb45439SRussell King #endif 335acb45439SRussell King 336acb45439SRussell King 337acb45439SRussell King /* 338acb45439SRussell King * Initialisation. 339acb45439SRussell King */ 340acb45439SRussell King static int ucb1x00_ts_add(struct ucb1x00_dev *dev) 341acb45439SRussell King { 342acb45439SRussell King struct ucb1x00_ts *ts; 343acb45439SRussell King 344bd622663SDmitry Torokhov ts = kzalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL); 345acb45439SRussell King if (!ts) 346acb45439SRussell King return -ENOMEM; 347acb45439SRussell King 348bd622663SDmitry Torokhov ts->idev = input_allocate_device(); 349bd622663SDmitry Torokhov if (!ts->idev) { 350bd622663SDmitry Torokhov kfree(ts); 351bd622663SDmitry Torokhov return -ENOMEM; 352bd622663SDmitry Torokhov } 353acb45439SRussell King 354acb45439SRussell King ts->ucb = dev->ucb; 355acb45439SRussell King ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC; 356acb45439SRussell King 357bd622663SDmitry Torokhov ts->idev->name = "Touchscreen panel"; 358bd622663SDmitry Torokhov ts->idev->id.product = ts->ucb->id; 359bd622663SDmitry Torokhov ts->idev->open = ucb1x00_ts_open; 360bd622663SDmitry Torokhov ts->idev->close = ucb1x00_ts_close; 361acb45439SRussell King 362bd622663SDmitry Torokhov __set_bit(EV_ABS, ts->idev->evbit); 363bd622663SDmitry Torokhov __set_bit(ABS_X, ts->idev->absbit); 364bd622663SDmitry Torokhov __set_bit(ABS_Y, ts->idev->absbit); 365bd622663SDmitry Torokhov __set_bit(ABS_PRESSURE, ts->idev->absbit); 366acb45439SRussell King 367bd622663SDmitry Torokhov input_register_device(ts->idev); 368acb45439SRussell King 369acb45439SRussell King dev->priv = ts; 370acb45439SRussell King 371acb45439SRussell King return 0; 372acb45439SRussell King } 373acb45439SRussell King 374acb45439SRussell King static void ucb1x00_ts_remove(struct ucb1x00_dev *dev) 375acb45439SRussell King { 376acb45439SRussell King struct ucb1x00_ts *ts = dev->priv; 377bd622663SDmitry Torokhov 378bd622663SDmitry Torokhov input_unregister_device(ts->idev); 379acb45439SRussell King kfree(ts); 380acb45439SRussell King } 381acb45439SRussell King 382acb45439SRussell King static struct ucb1x00_driver ucb1x00_ts_driver = { 383acb45439SRussell King .add = ucb1x00_ts_add, 384acb45439SRussell King .remove = ucb1x00_ts_remove, 385acb45439SRussell King .resume = ucb1x00_ts_resume, 386acb45439SRussell King }; 387acb45439SRussell King 388acb45439SRussell King static int __init ucb1x00_ts_init(void) 389acb45439SRussell King { 390acb45439SRussell King return ucb1x00_register_driver(&ucb1x00_ts_driver); 391acb45439SRussell King } 392acb45439SRussell King 393acb45439SRussell King static void __exit ucb1x00_ts_exit(void) 394acb45439SRussell King { 395acb45439SRussell King ucb1x00_unregister_driver(&ucb1x00_ts_driver); 396acb45439SRussell King } 397acb45439SRussell King 398acb45439SRussell King module_param(adcsync, int, 0444); 399acb45439SRussell King module_init(ucb1x00_ts_init); 400acb45439SRussell King module_exit(ucb1x00_ts_exit); 401acb45439SRussell King 402acb45439SRussell King MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); 403acb45439SRussell King MODULE_DESCRIPTION("UCB1x00 touchscreen driver"); 404acb45439SRussell King MODULE_LICENSE("GPL"); 405