diff options
Diffstat (limited to 'drivers/mfd/ucb1x00-ts.c')
| -rw-r--r-- | drivers/mfd/ucb1x00-ts.c | 399 |
1 files changed, 399 insertions, 0 deletions
diff --git a/drivers/mfd/ucb1x00-ts.c b/drivers/mfd/ucb1x00-ts.c new file mode 100644 index 00000000000..a851d65c7cf --- /dev/null +++ b/drivers/mfd/ucb1x00-ts.c @@ -0,0 +1,399 @@ +/* + * Touchscreen driver for UCB1x00-based touchscreens + * + * Copyright (C) 2001 Russell King, All Rights Reserved. + * Copyright (C) 2005 Pavel Machek + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * 21-Jan-2002 <jco@ict.es> : + * + * Added support for synchronous A/D mode. This mode is useful to + * avoid noise induced in the touchpanel by the LCD, provided that + * the UCB1x00 has a valid LCD sync signal routed to its ADCSYNC pin. + * It is important to note that the signal connected to the ADCSYNC + * pin should provide pulses even when the LCD is blanked, otherwise + * a pen touch needed to unblank the LCD will never be read. + */ +#include <linux/config.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/init.h> +#include <linux/smp.h> +#include <linux/smp_lock.h> +#include <linux/sched.h> +#include <linux/completion.h> +#include <linux/delay.h> +#include <linux/string.h> +#include <linux/input.h> +#include <linux/device.h> +#include <linux/suspend.h> +#include <linux/slab.h> +#include <linux/kthread.h> + +#include <asm/dma.h> +#include <asm/semaphore.h> + +#include "ucb1x00.h" + + +struct ucb1x00_ts { + struct input_dev idev; + struct ucb1x00 *ucb; + + wait_queue_head_t irq_wait; + struct task_struct *rtask; + u16 x_res; + u16 y_res; + + int restart:1; + int adcsync:1; +}; + +static int adcsync; + +static inline void ucb1x00_ts_evt_add(struct ucb1x00_ts *ts, u16 pressure, u16 x, u16 y) +{ + input_report_abs(&ts->idev, ABS_X, x); + input_report_abs(&ts->idev, ABS_Y, y); + input_report_abs(&ts->idev, ABS_PRESSURE, pressure); + input_sync(&ts->idev); +} + +static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts) +{ + input_report_abs(&ts->idev, ABS_PRESSURE, 0); + input_sync(&ts->idev); +} + +/* + * Switch to interrupt mode. + */ +static inline void ucb1x00_ts_mode_int(struct ucb1x00_ts *ts) +{ + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW | + UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND | + UCB_TS_CR_MODE_INT); +} + +/* + * Switch to pressure mode, and read pressure. We don't need to wait + * here, since both plates are being driven. + */ +static inline unsigned int ucb1x00_ts_read_pressure(struct ucb1x00_ts *ts) +{ + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW | + UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND | + UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); + + return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync); +} + +/* + * Switch to X position mode and measure Y plate. We switch the plate + * configuration in pressure mode, then switch to position mode. This + * gives a faster response time. Even so, we need to wait about 55us + * for things to stabilise. + */ +static inline unsigned int ucb1x00_ts_read_xpos(struct ucb1x00_ts *ts) +{ + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | + UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | + UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | + UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA); + + udelay(55); + + return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync); +} + +/* + * Switch to Y position mode and measure X plate. We switch the plate + * configuration in pressure mode, then switch to position mode. This + * gives a faster response time. Even so, we need to wait about 55us + * for things to stabilise. + */ +static inline unsigned int ucb1x00_ts_read_ypos(struct ucb1x00_ts *ts) +{ + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | + UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | + UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | + UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA); + + udelay(55); + + return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPX, ts->adcsync); +} + +/* + * Switch to X plate resistance mode. Set MX to ground, PX to + * supply. Measure current. + */ +static inline unsigned int ucb1x00_ts_read_xres(struct ucb1x00_ts *ts) +{ + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | + UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); + return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync); +} + +/* + * Switch to Y plate resistance mode. Set MY to ground, PY to + * supply. Measure current. + */ +static inline unsigned int ucb1x00_ts_read_yres(struct ucb1x00_ts *ts) +{ + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | + UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); + return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync); +} + +/* + * This is a RT kernel thread that handles the ADC accesses + * (mainly so we can use semaphores in the UCB1200 core code + * to serialise accesses to the ADC). + */ +static int ucb1x00_thread(void *_ts) +{ + struct ucb1x00_ts *ts = _ts; + struct task_struct *tsk = current; + DECLARE_WAITQUEUE(wait, tsk); + int valid; + + /* + * We could run as a real-time thread. However, thus far + * this doesn't seem to be necessary. + */ +// tsk->policy = SCHED_FIFO; +// tsk->rt_priority = 1; + + valid = 0; + + add_wait_queue(&ts->irq_wait, &wait); + while (!kthread_should_stop()) { + unsigned int x, y, p, val; + signed long timeout; + + ts->restart = 0; + + ucb1x00_adc_enable(ts->ucb); + + x = ucb1x00_ts_read_xpos(ts); + y = ucb1x00_ts_read_ypos(ts); + p = ucb1x00_ts_read_pressure(ts); + + /* + * Switch back to interrupt mode. + */ + ucb1x00_ts_mode_int(ts); + ucb1x00_adc_disable(ts->ucb); + + msleep(10); + + ucb1x00_enable(ts->ucb); + val = ucb1x00_reg_read(ts->ucb, UCB_TS_CR); + + if (val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW)) { + set_task_state(tsk, TASK_INTERRUPTIBLE); + + ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING); + ucb1x00_disable(ts->ucb); + + /* + * If we spat out a valid sample set last time, + * spit out a "pen off" sample here. + */ + if (valid) { + ucb1x00_ts_event_release(ts); + valid = 0; + } + + timeout = MAX_SCHEDULE_TIMEOUT; + } else { + ucb1x00_disable(ts->ucb); + + /* + * Filtering is policy. Policy belongs in user + * space. We therefore leave it to user space + * to do any filtering they please. + */ + if (!ts->restart) { + ucb1x00_ts_evt_add(ts, p, x, y); + valid = 1; + } + + set_task_state(tsk, TASK_INTERRUPTIBLE); + timeout = HZ / 100; + } + + try_to_freeze(); + + schedule_timeout(timeout); + } + + remove_wait_queue(&ts->irq_wait, &wait); + + ts->rtask = NULL; + return 0; +} + +/* + * We only detect touch screen _touches_ with this interrupt + * handler, and even then we just schedule our task. + */ +static void ucb1x00_ts_irq(int idx, void *id) +{ + struct ucb1x00_ts *ts = id; + ucb1x00_disable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING); + wake_up(&ts->irq_wait); +} + +static int ucb1x00_ts_open(struct input_dev *idev) +{ + struct ucb1x00_ts *ts = (struct ucb1x00_ts *)idev; + int ret = 0; + + BUG_ON(ts->rtask); + + init_waitqueue_head(&ts->irq_wait); + ret = ucb1x00_hook_irq(ts->ucb, UCB_IRQ_TSPX, ucb1x00_ts_irq, ts); + if (ret < 0) + goto out; + + /* + * If we do this at all, we should allow the user to + * measure and read the X and Y resistance at any time. + */ + ucb1x00_adc_enable(ts->ucb); + ts->x_res = ucb1x00_ts_read_xres(ts); + ts->y_res = ucb1x00_ts_read_yres(ts); + ucb1x00_adc_disable(ts->ucb); + + ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd"); + if (!IS_ERR(ts->rtask)) { + ret = 0; + } else { + ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts); + ts->rtask = NULL; + ret = -EFAULT; + } + + out: + return ret; +} + +/* + * Release touchscreen resources. Disable IRQs. + */ +static void ucb1x00_ts_close(struct input_dev *idev) +{ + struct ucb1x00_ts *ts = (struct ucb1x00_ts *)idev; + + if (ts->rtask) + kthread_stop(ts->rtask); + + ucb1x00_enable(ts->ucb); + ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts); + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0); + ucb1x00_disable(ts->ucb); +} + +#ifdef CONFIG_PM +static int ucb1x00_ts_resume(struct ucb1x00_dev *dev) +{ + struct ucb1x00_ts *ts = dev->priv; + + if (ts->rtask != NULL) { + /* + * Restart the TS thread to ensure the + * TS interrupt mode is set up again + * after sleep. + */ + ts->restart = 1; + wake_up(&ts->irq_wait); + } + return 0; +} +#else +#define ucb1x00_ts_resume NULL +#endif + + +/* + * Initialisation. + */ +static int ucb1x00_ts_add(struct ucb1x00_dev *dev) +{ + struct ucb1x00_ts *ts; + + ts = kmalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL); + if (!ts) + return -ENOMEM; + + memset(ts, 0, sizeof(struct ucb1x00_ts)); + + ts->ucb = dev->ucb; + ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC; + + ts->idev.name = "Touchscreen panel"; + ts->idev.id.product = ts->ucb->id; + ts->idev.open = ucb1x00_ts_open; + ts->idev.close = ucb1x00_ts_close; + + __set_bit(EV_ABS, ts->idev.evbit); + __set_bit(ABS_X, ts->idev.absbit); + __set_bit(ABS_Y, ts->idev.absbit); + __set_bit(ABS_PRESSURE, ts->idev.absbit); + + input_register_device(&ts->idev); + + dev->priv = ts; + + return 0; +} + +static void ucb1x00_ts_remove(struct ucb1x00_dev *dev) +{ + struct ucb1x00_ts *ts = dev->priv; + input_unregister_device(&ts->idev); + kfree(ts); +} + +static struct ucb1x00_driver ucb1x00_ts_driver = { + .add = ucb1x00_ts_add, + .remove = ucb1x00_ts_remove, + .resume = ucb1x00_ts_resume, +}; + +static int __init ucb1x00_ts_init(void) +{ + return ucb1x00_register_driver(&ucb1x00_ts_driver); +} + +static void __exit ucb1x00_ts_exit(void) +{ + ucb1x00_unregister_driver(&ucb1x00_ts_driver); +} + +module_param(adcsync, int, 0444); +module_init(ucb1x00_ts_init); +module_exit(ucb1x00_ts_exit); + +MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); +MODULE_DESCRIPTION("UCB1x00 touchscreen driver"); +MODULE_LICENSE("GPL"); |