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linux/drivers/input/touchscreen/ucb1400_ts.c
Vernon Sauder 48bdce4a2e Input: ucb1400_ts - IRQ probe fix 
The UCB1400 driver IRQ probe code fails to find an interrupt if all
the interrupts in the range 0-31 are nonprobe-able. This patch
removes the check of the return value so interrupts above 31 can be
detected.

Tested on InHand Fingertip4 PXA270 board.

Signed-off-by: Vernon Sauder <vsauder@inhand.com>
Acked-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2008-04-24 13:25:24 -04:00

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/*
* Philips UCB1400 touchscreen driver
*
* Author: Nicolas Pitre
* Created: September 25, 2006
* Copyright: MontaVista Software, Inc.
*
* 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 <sound/core.h>
#include <sound/ac97_codec.h>
/*
* Interesting UCB1400 AC-link registers
*/
#define UCB_IE_RIS 0x5e
#define UCB_IE_FAL 0x60
#define UCB_IE_STATUS 0x62
#define UCB_IE_CLEAR 0x62
#define UCB_IE_ADC (1 << 11)
#define UCB_IE_TSPX (1 << 12)
#define UCB_TS_CR 0x64
#define UCB_TS_CR_TSMX_POW (1 << 0)
#define UCB_TS_CR_TSPX_POW (1 << 1)
#define UCB_TS_CR_TSMY_POW (1 << 2)
#define UCB_TS_CR_TSPY_POW (1 << 3)
#define UCB_TS_CR_TSMX_GND (1 << 4)
#define UCB_TS_CR_TSPX_GND (1 << 5)
#define UCB_TS_CR_TSMY_GND (1 << 6)
#define UCB_TS_CR_TSPY_GND (1 << 7)
#define UCB_TS_CR_MODE_INT (0 << 8)
#define UCB_TS_CR_MODE_PRES (1 << 8)
#define UCB_TS_CR_MODE_POS (2 << 8)
#define UCB_TS_CR_BIAS_ENA (1 << 11)
#define UCB_TS_CR_TSPX_LOW (1 << 12)
#define UCB_TS_CR_TSMX_LOW (1 << 13)
#define UCB_ADC_CR 0x66
#define UCB_ADC_SYNC_ENA (1 << 0)
#define UCB_ADC_VREFBYP_CON (1 << 1)
#define UCB_ADC_INP_TSPX (0 << 2)
#define UCB_ADC_INP_TSMX (1 << 2)
#define UCB_ADC_INP_TSPY (2 << 2)
#define UCB_ADC_INP_TSMY (3 << 2)
#define UCB_ADC_INP_AD0 (4 << 2)
#define UCB_ADC_INP_AD1 (5 << 2)
#define UCB_ADC_INP_AD2 (6 << 2)
#define UCB_ADC_INP_AD3 (7 << 2)
#define UCB_ADC_EXT_REF (1 << 5)
#define UCB_ADC_START (1 << 7)
#define UCB_ADC_ENA (1 << 15)
#define UCB_ADC_DATA 0x68
#define UCB_ADC_DAT_VALID (1 << 15)
#define UCB_ADC_DAT_VALUE(x) ((x) & 0x3ff)
#define UCB_ID 0x7e
#define UCB_ID_1400 0x4304
struct ucb1400 {
struct snd_ac97 *ac97;
struct input_dev *ts_idev;
int irq;
wait_queue_head_t ts_wait;
struct task_struct *ts_task;
unsigned int irq_pending; /* not bit field shared */
unsigned int ts_restart:1;
unsigned int adcsync:1;
};
static int adcsync;
static int ts_delay = 55; /* us */
static int ts_delay_pressure; /* us */
static inline u16 ucb1400_reg_read(struct ucb1400 *ucb, u16 reg)
{
return ucb->ac97->bus->ops->read(ucb->ac97, reg);
}
static inline void ucb1400_reg_write(struct ucb1400 *ucb, u16 reg, u16 val)
{
ucb->ac97->bus->ops->write(ucb->ac97, reg, val);
}
static inline void ucb1400_adc_enable(struct ucb1400 *ucb)
{
ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA);
}
static unsigned int ucb1400_adc_read(struct ucb1400 *ucb, u16 adc_channel)
{
unsigned int val;
if (ucb->adcsync)
adc_channel |= UCB_ADC_SYNC_ENA;
ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA | adc_channel);
ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA | adc_channel | UCB_ADC_START);
for (;;) {
val = ucb1400_reg_read(ucb, UCB_ADC_DATA);
if (val & UCB_ADC_DAT_VALID)
break;
/* yield to other processes */
schedule_timeout_uninterruptible(1);
}
return UCB_ADC_DAT_VALUE(val);
}
static inline void ucb1400_adc_disable(struct ucb1400 *ucb)
{
ucb1400_reg_write(ucb, UCB_ADC_CR, 0);
}
/* Switch to interrupt mode. */
static inline void ucb1400_ts_mode_int(struct ucb1400 *ucb)
{
ucb1400_reg_write(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 ucb1400_ts_read_pressure(struct ucb1400 *ucb)
{
ucb1400_reg_write(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);
udelay(ts_delay_pressure);
return ucb1400_adc_read(ucb, UCB_ADC_INP_TSPY);
}
/*
* 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 *ucb)
{
ucb1400_reg_write(ucb, 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, 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, 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, UCB_ADC_INP_TSPY);
}
/*
* 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 *ucb)
{
ucb1400_reg_write(ucb, 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, 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, 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, UCB_ADC_INP_TSPX);
}
/*
* 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 *ucb)
{
ucb1400_reg_write(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 ucb1400_adc_read(ucb, 0);
}
/*
* 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 *ucb)
{
ucb1400_reg_write(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 ucb1400_adc_read(ucb, 0);
}
static inline int ucb1400_ts_pen_down(struct ucb1400 *ucb)
{
unsigned short val = ucb1400_reg_read(ucb, UCB_TS_CR);
return (val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW));
}
static inline void ucb1400_ts_irq_enable(struct ucb1400 *ucb)
{
ucb1400_reg_write(ucb, UCB_IE_CLEAR, UCB_IE_TSPX);
ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
ucb1400_reg_write(ucb, UCB_IE_FAL, UCB_IE_TSPX);
}
static inline void ucb1400_ts_irq_disable(struct ucb1400 *ucb)
{
ucb1400_reg_write(ucb, 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_sync(idev);
}
static void ucb1400_ts_event_release(struct input_dev *idev)
{
input_report_abs(idev, ABS_PRESSURE, 0);
input_sync(idev);
}
static void ucb1400_handle_pending_irq(struct ucb1400 *ucb)
{
unsigned int isr;
isr = ucb1400_reg_read(ucb, UCB_IE_STATUS);
ucb1400_reg_write(ucb, UCB_IE_CLEAR, isr);
ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
if (isr & UCB_IE_TSPX)
ucb1400_ts_irq_disable(ucb);
else
printk(KERN_ERR "ucb1400: unexpected IE_STATUS = %#x\n", isr);
enable_irq(ucb->irq);
}
static int ucb1400_ts_thread(void *_ucb)
{
struct ucb1400 *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);
x = ucb1400_ts_read_xpos(ucb);
y = ucb1400_ts_read_ypos(ucb);
p = ucb1400_ts_read_pressure(ucb);
ucb1400_adc_disable(ucb);
/* Switch back to interrupt mode. */
ucb1400_ts_mode_int(ucb);
msleep(10);
if (ucb1400_ts_pen_down(ucb)) {
ucb1400_ts_irq_enable(ucb);
/*
* 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 *ucb = devid;
if (irqnr == ucb->irq) {
disable_irq(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 *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 *ucb = input_get_drvdata(idev);
if (ucb->ts_task)
kthread_stop(ucb->ts_task);
ucb1400_ts_irq_disable(ucb);
ucb1400_reg_write(ucb, UCB_TS_CR, 0);
}
#ifdef CONFIG_PM
static int ucb1400_ts_resume(struct device *dev)
{
struct ucb1400 *ucb = dev_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
#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_detect_irq(struct ucb1400 *ucb)
{
unsigned long mask, timeout;
mask = probe_irq_on();
/* Enable the ADC interrupt. */
ucb1400_reg_write(ucb, UCB_IE_RIS, UCB_IE_ADC);
ucb1400_reg_write(ucb, UCB_IE_FAL, UCB_IE_ADC);
ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0xffff);
ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
/* Cause an ADC interrupt. */
ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA);
ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA | UCB_ADC_START);
/* Wait for the conversion to complete. */
timeout = jiffies + HZ/2;
while (!(ucb1400_reg_read(ucb, 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, UCB_ADC_CR, 0);
/* Disable and clear interrupt. */
ucb1400_reg_write(ucb, UCB_IE_RIS, 0);
ucb1400_reg_write(ucb, UCB_IE_FAL, 0);
ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0xffff);
ucb1400_reg_write(ucb, 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 device *dev)
{
struct ucb1400 *ucb;
struct input_dev *idev;
int error, id, x_res, y_res;
ucb = kzalloc(sizeof(struct ucb1400), GFP_KERNEL);
idev = input_allocate_device();
if (!ucb || !idev) {
error = -ENOMEM;
goto err_free_devs;
}
ucb->ts_idev = idev;
ucb->adcsync = adcsync;
ucb->ac97 = to_ac97_t(dev);
init_waitqueue_head(&ucb->ts_wait);
id = ucb1400_reg_read(ucb, UCB_ID);
if (id != UCB_ID_1400) {
error = -ENODEV;
goto err_free_devs;
}
error = ucb1400_detect_irq(ucb);
if (error) {
printk(KERN_ERR "UCB1400: IRQ probe failed\n");
goto err_free_devs;
}
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(idev, ucb);
idev->dev.parent = dev;
idev->name = "UCB1400 touchscreen interface";
idev->id.vendor = ucb1400_reg_read(ucb, AC97_VENDOR_ID1);
idev->id.product = id;
idev->open = ucb1400_ts_open;
idev->close = ucb1400_ts_close;
idev->evbit[0] = BIT_MASK(EV_ABS);
ucb1400_adc_enable(ucb);
x_res = ucb1400_ts_read_xres(ucb);
y_res = ucb1400_ts_read_yres(ucb);
ucb1400_adc_disable(ucb);
printk(KERN_DEBUG "UCB1400: x/y = %d/%d\n", x_res, y_res);
input_set_abs_params(idev, ABS_X, 0, x_res, 0, 0);
input_set_abs_params(idev, ABS_Y, 0, y_res, 0, 0);
input_set_abs_params(idev, ABS_PRESSURE, 0, 0, 0, 0);
error = input_register_device(idev);
if (error)
goto err_free_irq;
dev_set_drvdata(dev, ucb);
return 0;
err_free_irq:
free_irq(ucb->irq, ucb);
err_free_devs:
input_free_device(idev);
kfree(ucb);
return error;
}
static int ucb1400_ts_remove(struct device *dev)
{
struct ucb1400 *ucb = dev_get_drvdata(dev);
free_irq(ucb->irq, ucb);
input_unregister_device(ucb->ts_idev);
dev_set_drvdata(dev, NULL);
kfree(ucb);
return 0;
}
static struct device_driver ucb1400_ts_driver = {
.name = "ucb1400_ts",
.owner = THIS_MODULE,
.bus = &ac97_bus_type,
.probe = ucb1400_ts_probe,
.remove = ucb1400_ts_remove,
.resume = ucb1400_ts_resume,
};
static int __init ucb1400_ts_init(void)
{
return driver_register(&ucb1400_ts_driver);
}
static void __exit ucb1400_ts_exit(void)
{
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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