/*
* linux/drivers/mfd/ucb1x00-ts.c
*
* Copyright (C) 2001 Russell King, All Rights Reserved.
*
* 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 <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 semaphore sem;
struct completion init_exit;
struct task_struct *rtask;
int use_count;
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;
ts->rtask = tsk;
daemonize("ktsd");
/* only want to receive SIGKILL */
allow_signal(SIGKILL);
/*
* 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;
complete(&ts->init_exit);
valid = 0;
add_wait_queue(&ts->irq_wait, &wait);
for (;;) {
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);
set_task_state(tsk, TASK_UNINTERRUPTIBLE);
schedule_timeout(HZ / 100);
if (signal_pending(tsk))
break;
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);
if (signal_pending(tsk))
break;
}
remove_wait_queue(&ts->irq_wait, &wait);
ts->rtask = NULL;
complete_and_exit(&ts->init_exit, 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;
if (down_interruptible(&ts->sem))
return -EINTR;
if (ts->use_count++ != 0)
goto out;
if (ts->rtask)
panic("ucb1x00: rtask running?");
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);
init_completion(&ts->init_exit);
ret = kernel_thread(ucb1x00_thread, ts, CLONE_KERNEL);
if (ret >= 0) {
wait_for_completion(&ts->init_exit);
ret = 0;
} else {
ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
}
out:
if (ret)
ts->use_count--;
up(&ts->sem);
return ret;
}
/*
* Release touchscreen resources. Disable IRQs.
*/
static void ucb1x00_ts_close(struct input_dev *idev)
{
struct ucb1x00_ts *ts = (struct ucb1x00_ts *)idev;
down(&ts->sem);
if (--ts->use_count == 0) {
if (ts->rtask) {
send_sig(SIGKILL, ts->rtask, 1);
wait_for_completion(&ts->init_exit);
}
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);
}
up(&ts->sem);
}
#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;
init_MUTEX(&ts->sem);
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");
