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Input: ucb1400_ts - convert to threaded IRQ

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Instead of manually create and handler kernel thread switch to threaded
IRQ and let kernel IRQ core manage thread for us.

Acked-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This commit is contained in:
Dmitry Torokhov 2012-01-04 22:18:42 -08:00
parent 75072323a2
commit c899afedf1
2 changed files with 115 additions and 126 deletions
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239
drivers/input/touchscreen/ucb1400_ts.c
View File

@ -20,24 +20,24 @@
#include <linux/module.h> #include <linux/module.h>
#include <linux/init.h> #include <linux/init.h>
#include <linux/completion.h>
#include <linux/delay.h> #include <linux/delay.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/input.h> #include <linux/input.h>
#include <linux/device.h> #include <linux/device.h>
#include <linux/interrupt.h> #include <linux/interrupt.h>
#include <linux/suspend.h>
#include <linux/kthread.h>
#include <linux/freezer.h>
#include <linux/ucb1400.h> #include <linux/ucb1400.h>
#define UCB1400_TS_POLL_PERIOD 10 /* ms */
static int adcsync; static int adcsync;
static int ts_delay = 55; /* us */ static int ts_delay = 55; /* us */
static int ts_delay_pressure; /* us */ static int ts_delay_pressure; /* us */
/* Switch to interrupt mode. */ /* Switch to interrupt mode. */
static void ucb1400_ts_mode_int(struct snd_ac97 *ac97) static void ucb1400_ts_mode_int(struct ucb1400_ts *ucb)
{ {
ucb1400_reg_write(ac97, UCB_TS_CR, ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW | UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND | UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
UCB_TS_CR_MODE_INT); UCB_TS_CR_MODE_INT);
@ -53,7 +53,9 @@ static unsigned int ucb1400_ts_read_pressure(struct ucb1400_ts *ucb)
UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW | UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND | UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
udelay(ts_delay_pressure); udelay(ts_delay_pressure);
return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync); return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
} }
@ -127,26 +129,26 @@ static unsigned int ucb1400_ts_read_yres(struct ucb1400_ts *ucb)
return ucb1400_adc_read(ucb->ac97, 0, adcsync); return ucb1400_adc_read(ucb->ac97, 0, adcsync);
} }
static int ucb1400_ts_pen_up(struct snd_ac97 *ac97) static int ucb1400_ts_pen_up(struct ucb1400_ts *ucb)
{ {
unsigned short val = ucb1400_reg_read(ac97, UCB_TS_CR); unsigned short val = ucb1400_reg_read(ucb->ac97, UCB_TS_CR);
return val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW); return val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW);
} }
static void ucb1400_ts_irq_enable(struct snd_ac97 *ac97) static void ucb1400_ts_irq_enable(struct ucb1400_ts *ucb)
{ {
ucb1400_reg_write(ac97, UCB_IE_CLEAR, UCB_IE_TSPX); ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, UCB_IE_TSPX);
ucb1400_reg_write(ac97, UCB_IE_CLEAR, 0); ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
ucb1400_reg_write(ac97, UCB_IE_FAL, UCB_IE_TSPX); ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_TSPX);
} }
static void ucb1400_ts_irq_disable(struct snd_ac97 *ac97) static void ucb1400_ts_irq_disable(struct ucb1400_ts *ucb)
{ {
ucb1400_reg_write(ac97, UCB_IE_FAL, 0); ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
} }
static void ucb1400_ts_evt_add(struct input_dev *idev, u16 pressure, u16 x, u16 y) static void ucb1400_ts_report_event(struct input_dev *idev, u16 pressure, u16 x, u16 y)
{ {
input_report_abs(idev, ABS_X, x); input_report_abs(idev, ABS_X, x);
input_report_abs(idev, ABS_Y, y); input_report_abs(idev, ABS_Y, y);
@ -162,7 +164,7 @@ static void ucb1400_ts_event_release(struct input_dev *idev)
input_sync(idev); input_sync(idev);
} }
static void ucb1400_handle_pending_irq(struct ucb1400_ts *ucb) static void ucb1400_clear_pending_irq(struct ucb1400_ts *ucb)
{ {
unsigned int isr; unsigned int isr;
@ -171,32 +173,34 @@ static void ucb1400_handle_pending_irq(struct ucb1400_ts *ucb)
ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0); ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
if (isr & UCB_IE_TSPX) if (isr & UCB_IE_TSPX)
ucb1400_ts_irq_disable(ucb->ac97); ucb1400_ts_irq_disable(ucb);
else else
dev_dbg(&ucb->ts_idev->dev, "ucb1400: unexpected IE_STATUS = %#x\n", isr); dev_dbg(&ucb->ts_idev->dev,
enable_irq(ucb->irq); "ucb1400: unexpected IE_STATUS = %#x\n", isr);
} }
static int ucb1400_ts_thread(void *_ucb) /*
* 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. Therefore the driver is forced to use threaded interrupt
* handler.
*/
static irqreturn_t ucb1400_irq(int irqnr, void *devid)
{ {
struct ucb1400_ts *ucb = _ucb; struct ucb1400_ts *ucb = devid;
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; unsigned int x, y, p;
long timeout; bool penup;
ucb->ts_restart = 0; if (unlikely(irqnr != ucb->irq))
return IRQ_NONE;
if (ucb->irq_pending) { ucb1400_clear_pending_irq(ucb);
ucb->irq_pending = 0;
ucb1400_handle_pending_irq(ucb); /* Start with a small delay before checking pendown state */
} msleep(UCB1400_TS_POLL_PERIOD);
while (!ucb->stopped && !(penup = ucb1400_ts_pen_up(ucb))) {
ucb1400_adc_enable(ucb->ac97); ucb1400_adc_enable(ucb->ac97);
x = ucb1400_ts_read_xpos(ucb); x = ucb1400_ts_read_xpos(ucb);
@ -204,91 +208,62 @@ static int ucb1400_ts_thread(void *_ucb)
p = ucb1400_ts_read_pressure(ucb); p = ucb1400_ts_read_pressure(ucb);
ucb1400_adc_disable(ucb->ac97); ucb1400_adc_disable(ucb->ac97);
ucb1400_ts_report_event(ucb->ts_idev, p, x, y);
wait_event_timeout(ucb->ts_wait, ucb->stopped,
msecs_to_jiffies(UCB1400_TS_POLL_PERIOD));
}
ucb1400_ts_event_release(ucb->ts_idev);
if (!ucb->stopped) {
/* Switch back to interrupt mode. */ /* Switch back to interrupt mode. */
ucb1400_ts_mode_int(ucb->ac97); ucb1400_ts_mode_int(ucb);
ucb1400_ts_irq_enable(ucb);
msleep(10);
if (ucb1400_ts_pen_up(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; return IRQ_HANDLED;
} 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;
} }
/* static void ucb1400_ts_stop(struct ucb1400_ts *ucb)
* 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; /* Signal IRQ thread to stop polling and disable the handler. */
ucb->stopped = true;
if (irqnr == ucb->irq) { mb();
disable_irq_nosync(ucb->irq);
ucb->irq_pending = 1;
wake_up(&ucb->ts_wait); wake_up(&ucb->ts_wait);
return IRQ_HANDLED; disable_irq(ucb->irq);
}
return IRQ_NONE; ucb1400_ts_irq_disable(ucb);
ucb1400_reg_write(ucb->ac97, UCB_TS_CR, 0);
}
/* Must be called with ts->lock held */
static void ucb1400_ts_start(struct ucb1400_ts *ucb)
{
/* Tell IRQ thread that it may poll the device. */
ucb->stopped = false;
mb();
ucb1400_ts_mode_int(ucb);
ucb1400_ts_irq_enable(ucb);
enable_irq(ucb->irq);
} }
static int ucb1400_ts_open(struct input_dev *idev) static int ucb1400_ts_open(struct input_dev *idev)
{ {
struct ucb1400_ts *ucb = input_get_drvdata(idev); struct ucb1400_ts *ucb = input_get_drvdata(idev);
int ret = 0;
BUG_ON(ucb->ts_task); ucb1400_ts_start(ucb);
ucb->ts_task = kthread_run(ucb1400_ts_thread, ucb, "UCB1400_ts"); return 0;
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) static void ucb1400_ts_close(struct input_dev *idev)
{ {
struct ucb1400_ts *ucb = input_get_drvdata(idev); struct ucb1400_ts *ucb = input_get_drvdata(idev);
if (ucb->ts_task) ucb1400_ts_stop(ucb);
kthread_stop(ucb->ts_task);
ucb1400_ts_irq_disable(ucb->ac97);
ucb1400_reg_write(ucb->ac97, UCB_TS_CR, 0);
} }
#ifndef NO_IRQ #ifndef NO_IRQ
@ -342,11 +317,11 @@ static int __devinit ucb1400_ts_detect_irq(struct ucb1400_ts *ucb)
return 0; return 0;
} }
static int __devinit ucb1400_ts_probe(struct platform_device *dev) static int __devinit ucb1400_ts_probe(struct platform_device *pdev)
{ {
struct ucb1400_ts *ucb = pdev->dev.platform_data;
int error, x_res, y_res; int error, x_res, y_res;
u16 fcsr; u16 fcsr;
struct ucb1400_ts *ucb = dev->dev.platform_data;
ucb->ts_idev = input_allocate_device(); ucb->ts_idev = input_allocate_device();
if (!ucb->ts_idev) { if (!ucb->ts_idev) {
@ -362,21 +337,13 @@ static int __devinit ucb1400_ts_probe(struct platform_device *dev)
goto err_free_devs; goto err_free_devs;
} }
} }
printk(KERN_DEBUG "UCB1400: found IRQ %d\n", ucb->irq);
init_waitqueue_head(&ucb->ts_wait); 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); input_set_drvdata(ucb->ts_idev, ucb);
ucb->ts_idev->dev.parent = &dev->dev; ucb->ts_idev->dev.parent = &pdev->dev;
ucb->ts_idev->name = "UCB1400 touchscreen interface"; ucb->ts_idev->name = "UCB1400 touchscreen interface";
ucb->ts_idev->id.vendor = ucb1400_reg_read(ucb->ac97, ucb->ts_idev->id.vendor = ucb1400_reg_read(ucb->ac97,
AC97_VENDOR_ID1); AC97_VENDOR_ID1);
@ -404,6 +371,17 @@ static int __devinit ucb1400_ts_probe(struct platform_device *dev)
input_set_abs_params(ucb->ts_idev, ABS_Y, 0, y_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); input_set_abs_params(ucb->ts_idev, ABS_PRESSURE, 0, 0, 0, 0);
ucb1400_ts_stop(ucb);
error = request_threaded_irq(ucb->irq, NULL, ucb1400_irq,
IRQF_TRIGGER_RISING | IRQF_ONESHOT,
"UCB1400", ucb);
if (error) {
printk(KERN_ERR "ucb1400: unable to grab irq%d: %d\n",
ucb->irq, error);
goto err_free_devs;
}
error = input_register_device(ucb->ts_idev); error = input_register_device(ucb->ts_idev);
if (error) if (error)
goto err_free_irq; goto err_free_irq;
@ -418,9 +396,9 @@ err:
return error; return error;
} }
static int __devexit ucb1400_ts_remove(struct platform_device *dev) static int __devexit ucb1400_ts_remove(struct platform_device *pdev)
{ {
struct ucb1400_ts *ucb = dev->dev.platform_data; struct ucb1400_ts *ucb = pdev->dev.platform_data;
free_irq(ucb->irq, ucb); free_irq(ucb->irq, ucb);
input_unregister_device(ucb->ts_idev); input_unregister_device(ucb->ts_idev);
@ -429,24 +407,37 @@ static int __devexit ucb1400_ts_remove(struct platform_device *dev)
} }
#ifdef CONFIG_PM_SLEEP #ifdef CONFIG_PM_SLEEP
static int ucb1400_ts_suspend(struct device *dev)
{
struct ucb1400_ts *ucb = dev->platform_data;
struct input_dev *idev = ucb->ts_idev;
mutex_lock(&idev->mutex);
if (idev->users)
ucb1400_ts_start(ucb);
mutex_unlock(&idev->mutex);
return 0;
}
static int ucb1400_ts_resume(struct device *dev) static int ucb1400_ts_resume(struct device *dev)
{ {
struct ucb1400_ts *ucb = dev->platform_data; struct ucb1400_ts *ucb = dev->platform_data;
struct input_dev *idev = ucb->ts_idev;
if (ucb->ts_task) { mutex_lock(&idev->mutex);
/*
* Restart the TS thread to ensure the if (idev->users)
* TS interrupt mode is set up again ucb1400_ts_stop(ucb);
* after sleep.
*/ mutex_unlock(&idev->mutex);
ucb->ts_restart = 1;
wake_up(&ucb->ts_wait);
}
return 0; return 0;
} }
#endif #endif
static SIMPLE_DEV_PM_OPS(ucb1400_ts_pm_ops, NULL, ucb1400_ts_resume); static SIMPLE_DEV_PM_OPS(ucb1400_ts_pm_ops,
ucb1400_ts_suspend, ucb1400_ts_resume);
static struct platform_driver ucb1400_ts_driver = { static struct platform_driver ucb1400_ts_driver = {
.probe = ucb1400_ts_probe, .probe = ucb1400_ts_probe,

6
include/linux/ucb1400.h
View File

@ -96,13 +96,11 @@ struct ucb1400_gpio {
struct ucb1400_ts { struct ucb1400_ts {
struct input_dev *ts_idev; struct input_dev *ts_idev;
struct task_struct *ts_task;
int id; int id;
wait_queue_head_t ts_wait;
unsigned int ts_restart:1;
int irq; int irq;
unsigned int irq_pending; /* not bit field shared */
struct snd_ac97 *ac97; struct snd_ac97 *ac97;
wait_queue_head_t ts_wait;
bool stopped;
}; };
struct ucb1400 { struct ucb1400 {