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linux-stable/drivers/input/touchscreen/ucb1400_ts.c
Ben Nizette 3deb649e65 Input: ucb1400 - use disable_irq_nosync() in irq handler 
disable_irq() waits for all running handlers to complete before
returning.  As such, if it's used to disable an interrupt from
that interrupt's handler it will deadlock.  This replaces the
dangerous instances with the _nosync() variant which doesn't have
this problem.

Signed-off-by: Ben Nizette <bn@niasdigital.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2009-04-17 20:42:06 -07:00

474 lines
12 KiB
C
Raw Blame History

/*
* Philips UCB1400 touchscreen driver
*
* Author: Nicolas Pitre
* Created: September 25, 2006
* Copyright: MontaVista Software, Inc.
*
* Spliting done by: Marek Vasut <marek.vasut@gmail.com>
* If something doesnt work and it worked before spliting, e-mail me,
* dont bother Nicolas please ;-)
*
* 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.
*
* This code is heavily based on ucb1x00-*.c copyrighted by Russell King
* covering the UCB1100, UCB1200 and UCB1300.. Support for the UCB1400 has
* been made separate from ucb1x00-core/ucb1x00-ts on Russell's request.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/input.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/suspend.h>
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/freezer.h>
#include <linux/ucb1400.h>
static int adcsync;
static int ts_delay = 55; /* us */
static int ts_delay_pressure; /* us */
/* Switch to interrupt mode. */
static inline void ucb1400_ts_mode_int(struct snd_ac97 *ac97)
{
ucb1400_reg_write(ac97, 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 ucb1400_ts_read_pressure(struct ucb1400_ts *ucb)
{
ucb1400_reg_write(ucb->ac97, 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);
udelay(ts_delay_pressure);
return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, 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 ucb1400_ts_read_xpos(struct ucb1400_ts *ucb)
{
ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
udelay(ts_delay);
return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, 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 ucb1400_ts_read_ypos(struct ucb1400_ts *ucb)
{
ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
udelay(ts_delay);
return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPX, adcsync);
}
/*
* Switch to X plate resistance mode. Set MX to ground, PX to
* supply. Measure current.
*/
static inline unsigned int ucb1400_ts_read_xres(struct ucb1400_ts *ucb)
{
ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
return ucb1400_adc_read(ucb->ac97, 0, adcsync);
}
/*
* Switch to Y plate resistance mode. Set MY to ground, PY to
* supply. Measure current.
*/
static inline unsigned int ucb1400_ts_read_yres(struct ucb1400_ts *ucb)
{
ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
return ucb1400_adc_read(ucb->ac97, 0, adcsync);
}
static inline int ucb1400_ts_pen_down(struct snd_ac97 *ac97)
{
unsigned short val = ucb1400_reg_read(ac97, UCB_TS_CR);
return val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW);
}
static inline void ucb1400_ts_irq_enable(struct snd_ac97 *ac97)
{
ucb1400_reg_write(ac97, UCB_IE_CLEAR, UCB_IE_TSPX);
ucb1400_reg_write(ac97, UCB_IE_CLEAR, 0);
ucb1400_reg_write(ac97, UCB_IE_FAL, UCB_IE_TSPX);
}
static inline void ucb1400_ts_irq_disable(struct snd_ac97 *ac97)
{
ucb1400_reg_write(ac97, UCB_IE_FAL, 0);
}
static void ucb1400_ts_evt_add(struct input_dev *idev, u16 pressure, u16 x, u16 y)
{
input_report_abs(idev, ABS_X, x);
input_report_abs(idev, ABS_Y, y);
input_report_abs(idev, ABS_PRESSURE, pressure);
input_report_key(idev, BTN_TOUCH, 1);
input_sync(idev);
}
static void ucb1400_ts_event_release(struct input_dev *idev)
{
input_report_abs(idev, ABS_PRESSURE, 0);
input_report_key(idev, BTN_TOUCH, 0);
input_sync(idev);
}
static void ucb1400_handle_pending_irq(struct ucb1400_ts *ucb)
{
unsigned int isr;
isr = ucb1400_reg_read(ucb->ac97, UCB_IE_STATUS);
ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, isr);
ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
if (isr & UCB_IE_TSPX) {
ucb1400_ts_irq_disable(ucb->ac97);
enable_irq(ucb->irq);
} else
printk(KERN_ERR "ucb1400: unexpected IE_STATUS = %#x\n", isr);
}
static int ucb1400_ts_thread(void *_ucb)
{
struct ucb1400_ts *ucb = _ucb;
struct task_struct *tsk = current;
int valid = 0;
struct sched_param param = { .sched_priority = 1 };
sched_setscheduler(tsk, SCHED_FIFO, &param);
set_freezable();
while (!kthread_should_stop()) {
unsigned int x, y, p;
long timeout;
ucb->ts_restart = 0;
if (ucb->irq_pending) {
ucb->irq_pending = 0;
ucb1400_handle_pending_irq(ucb);
}
ucb1400_adc_enable(ucb->ac97);
x = ucb1400_ts_read_xpos(ucb);
y = ucb1400_ts_read_ypos(ucb);
p = ucb1400_ts_read_pressure(ucb);
ucb1400_adc_disable(ucb->ac97);
/* Switch back to interrupt mode. */
ucb1400_ts_mode_int(ucb->ac97);
msleep(10);
if (ucb1400_ts_pen_down(ucb->ac97)) {
ucb1400_ts_irq_enable(ucb->ac97);
/*
* If we spat out a valid sample set last time,
* spit out a "pen off" sample here.
*/
if (valid) {
ucb1400_ts_event_release(ucb->ts_idev);
valid = 0;
}
timeout = MAX_SCHEDULE_TIMEOUT;
} else {
valid = 1;
ucb1400_ts_evt_add(ucb->ts_idev, p, x, y);
timeout = msecs_to_jiffies(10);
}
wait_event_freezable_timeout(ucb->ts_wait,
ucb->irq_pending || ucb->ts_restart ||
kthread_should_stop(), timeout);
}
/* Send the "pen off" if we are stopping with the pen still active */
if (valid)
ucb1400_ts_event_release(ucb->ts_idev);
ucb->ts_task = NULL;
return 0;
}
/*
* A restriction with interrupts exists when using the ucb1400, as
* the codec read/write routines may sleep while waiting for codec
* access completion and uses semaphores for access control to the
* AC97 bus. A complete codec read cycle could take anywhere from
* 60 to 100uSec so we *definitely* don't want to spin inside the
* interrupt handler waiting for codec access. So, we handle the
* interrupt by scheduling a RT kernel thread to run in process
* context instead of interrupt context.
*/
static irqreturn_t ucb1400_hard_irq(int irqnr, void *devid)
{
struct ucb1400_ts *ucb = devid;
if (irqnr == ucb->irq) {
disable_irq_nosync(ucb->irq);
ucb->irq_pending = 1;
wake_up(&ucb->ts_wait);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
static int ucb1400_ts_open(struct input_dev *idev)
{
struct ucb1400_ts *ucb = input_get_drvdata(idev);
int ret = 0;
BUG_ON(ucb->ts_task);
ucb->ts_task = kthread_run(ucb1400_ts_thread, ucb, "UCB1400_ts");
if (IS_ERR(ucb->ts_task)) {
ret = PTR_ERR(ucb->ts_task);
ucb->ts_task = NULL;
}
return ret;
}
static void ucb1400_ts_close(struct input_dev *idev)
{
struct ucb1400_ts *ucb = input_get_drvdata(idev);
if (ucb->ts_task)
kthread_stop(ucb->ts_task);
ucb1400_ts_irq_disable(ucb->ac97);
ucb1400_reg_write(ucb->ac97, UCB_TS_CR, 0);
}
#ifndef NO_IRQ
#define NO_IRQ 0
#endif
/*
* Try to probe our interrupt, rather than relying on lots of
* hard-coded machine dependencies.
*/
static int ucb1400_ts_detect_irq(struct ucb1400_ts *ucb)
{
unsigned long mask, timeout;
mask = probe_irq_on();
/* Enable the ADC interrupt. */
ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, UCB_IE_ADC);
ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_ADC);
ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
/* Cause an ADC interrupt. */
ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA);
ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA | UCB_ADC_START);
/* Wait for the conversion to complete. */
timeout = jiffies + HZ/2;
while (!(ucb1400_reg_read(ucb->ac97, UCB_ADC_DATA) &
UCB_ADC_DAT_VALID)) {
cpu_relax();
if (time_after(jiffies, timeout)) {
printk(KERN_ERR "ucb1400: timed out in IRQ probe\n");
probe_irq_off(mask);
return -ENODEV;
}
}
ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, 0);
/* Disable and clear interrupt. */
ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, 0);
ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
/* Read triggered interrupt. */
ucb->irq = probe_irq_off(mask);
if (ucb->irq < 0 || ucb->irq == NO_IRQ)
return -ENODEV;
return 0;
}
static int ucb1400_ts_probe(struct platform_device *dev)
{
int error, x_res, y_res;
struct ucb1400_ts *ucb = dev->dev.platform_data;
ucb->ts_idev = input_allocate_device();
if (!ucb->ts_idev) {
error = -ENOMEM;
goto err;
}
error = ucb1400_ts_detect_irq(ucb);
if (error) {
printk(KERN_ERR "UCB1400: IRQ probe failed\n");
goto err_free_devs;
}
init_waitqueue_head(&ucb->ts_wait);
error = request_irq(ucb->irq, ucb1400_hard_irq, IRQF_TRIGGER_RISING,
"UCB1400", ucb);
if (error) {
printk(KERN_ERR "ucb1400: unable to grab irq%d: %d\n",
ucb->irq, error);
goto err_free_devs;
}
printk(KERN_DEBUG "UCB1400: found IRQ %d\n", ucb->irq);
input_set_drvdata(ucb->ts_idev, ucb);
ucb->ts_idev->dev.parent = &dev->dev;
ucb->ts_idev->name = "UCB1400 touchscreen interface";
ucb->ts_idev->id.vendor = ucb1400_reg_read(ucb->ac97,
AC97_VENDOR_ID1);
ucb->ts_idev->id.product = ucb->id;
ucb->ts_idev->open = ucb1400_ts_open;
ucb->ts_idev->close = ucb1400_ts_close;
ucb->ts_idev->evbit[0] = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY);
ucb->ts_idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
ucb1400_adc_enable(ucb->ac97);
x_res = ucb1400_ts_read_xres(ucb);
y_res = ucb1400_ts_read_yres(ucb);
ucb1400_adc_disable(ucb->ac97);
printk(KERN_DEBUG "UCB1400: x/y = %d/%d\n", x_res, y_res);
input_set_abs_params(ucb->ts_idev, ABS_X, 0, x_res, 0, 0);
input_set_abs_params(ucb->ts_idev, ABS_Y, 0, y_res, 0, 0);
input_set_abs_params(ucb->ts_idev, ABS_PRESSURE, 0, 0, 0, 0);
error = input_register_device(ucb->ts_idev);
if (error)
goto err_free_irq;
return 0;
err_free_irq:
free_irq(ucb->irq, ucb);
err_free_devs:
input_free_device(ucb->ts_idev);
err:
return error;
}
static int ucb1400_ts_remove(struct platform_device *dev)
{
struct ucb1400_ts *ucb = dev->dev.platform_data;
free_irq(ucb->irq, ucb);
input_unregister_device(ucb->ts_idev);
return 0;
}
#ifdef CONFIG_PM
static int ucb1400_ts_resume(struct platform_device *dev)
{
struct ucb1400_ts *ucb = platform_get_drvdata(dev);
if (ucb->ts_task) {
/*
* Restart the TS thread to ensure the
* TS interrupt mode is set up again
* after sleep.
*/
ucb->ts_restart = 1;
wake_up(&ucb->ts_wait);
}
return 0;
}
#else
#define ucb1400_ts_resume NULL
#endif
static struct platform_driver ucb1400_ts_driver = {
.probe = ucb1400_ts_probe,
.remove = ucb1400_ts_remove,
.resume = ucb1400_ts_resume,
.driver = {
.name = "ucb1400_ts",
},
};
static int __init ucb1400_ts_init(void)
{
return platform_driver_register(&ucb1400_ts_driver);
}
static void __exit ucb1400_ts_exit(void)
{
platform_driver_unregister(&ucb1400_ts_driver);
}
module_param(adcsync, bool, 0444);
MODULE_PARM_DESC(adcsync, "Synchronize touch readings with ADCSYNC pin.");
module_param(ts_delay, int, 0444);
MODULE_PARM_DESC(ts_delay, "Delay between panel setup and"
" position read. Default = 55us.");
module_param(ts_delay_pressure, int, 0444);
MODULE_PARM_DESC(ts_delay_pressure,
"delay between panel setup and pressure read."
" Default = 0us.");
module_init(ucb1400_ts_init);
module_exit(ucb1400_ts_exit);
MODULE_DESCRIPTION("Philips UCB1400 touchscreen driver");
MODULE_LICENSE("GPL");
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