linux/drivers/mfd/ucb1x00-ts.c
Jochen Friedrich 9063f1f15e mfd: Fix NULL pointer due to non-initialized ucb1x00-ts absinfo
Call input_set_abs_params instead of manually setting absbit only.
This fixes this oops:

Unable to handle kernel NULL pointer dereference at virtual address 00000024
Internal error: Oops: 41b67017 [#1]
CPU: 0    Not tainted  (2.6.37 #4)
pc : [<c016d1fc>]    lr : [<00000000>]    psr: 20000093
sp : c19e5f30  ip : c19e5e6c  fp : c19e5f58
r10: 00000000  r9 : c19e4000  r8 : 00000003
r7 : 000001e4  r6 : 00000001  r5 : c1854400  r4 : 00000003
r3 : 00000018  r2 : 00000018  r1 : 00000018  r0 : c185447c
Flags: nzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
Control: c1b6717f  Table: c1b6717f  DAC: 00000017
Stack: (0xc19e5f30 to 0xc19e6000)
5f20:                                     00000003 00000003 c1854400 00000013
5f40: 00000001 000001e4 000001c5 c19e5f80 c19e5f5c c016d5e8 c016cf5c 000001e4
5f60: c1854400 c18b5860 00000000 00000171 000001e4 c19e5fc4 c19e5f84 c01559a4
5f80: c016d584 c18b5868 00000000 c1bb5c40 c0035afc c18b5868 c18b5868 c1a55d54
5fa0: c18b5860 c0155750 00000013 00000000 00000000 00000000 c19e5ff4 c19e5fc8
5fc0: c0050174 c015575c 00000000 c18b5860 00000000 c19e5fd4 c19e5fd4 c1a55d54
5fe0: c00500f0 c003b464 00000000 c19e5ff8 c003b464 c00500fc 04000400 04000400
Backtrace:
Function entered at [<c016cf50>] from [<c016d5e8>]
Function entered at [<c016d578>] from [<c01559a4>]
 r8:000001e4 r7:00000171 r6:00000000 r5:c18b5860 r4:c1854400
Function entered at [<c0155750>] from [<c0050174>]
Function entered at [<c00500f0>] from [<c003b464>]
 r6:c003b464 r5:c00500f0 r4:c1a55d54
Code: e59520fc e1a03286 e0433186 e0822003 (e592000c)

>>PC;  c016d1fc <input_handle_event+2ac/5a0>   <=====

Trace; c016cf50 <input_handle_event+0/5a0>
Trace; c016d5e8 <input_event+70/88>
Trace; c016d578 <input_event+0/88>
Trace; c01559a4 <ucb1x00_thread+254/2dc>
Trace; c0155750 <ucb1x00_thread+0/2dc>
Trace; c0050174 <kthread+84/8c>
Trace; c00500f0 <kthread+0/8c>
Trace; c003b464 <do_exit+0/624>

Signed-off-by: Jochen Friedrich <jochen@scram.de>
CC: stable@kernel.org
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2011-03-02 10:57:49 +01:00

445 lines
11 KiB
C

/*
* 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/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/smp.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/freezer.h>
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/mfd/ucb1x00.h>
#include <mach/dma.h>
#include <mach/collie.h>
#include <asm/mach-types.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;
unsigned int restart:1;
unsigned int adcsync:1;
};
static int adcsync;
static inline void ucb1x00_ts_evt_add(struct ucb1x00_ts *ts, u16 pressure, u16 x, u16 y)
{
struct input_dev *idev = ts->idev;
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 inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts)
{
struct input_dev *idev = ts->idev;
input_report_abs(idev, ABS_PRESSURE, 0);
input_sync(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)
{
if (machine_is_collie()) {
ucb1x00_io_write(ts->ucb, COLLIE_TC35143_GPIO_TBL_CHK, 0);
ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
UCB_TS_CR_TSPX_POW | UCB_TS_CR_TSMX_POW |
UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
udelay(55);
return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_AD2, ts->adcsync);
} else {
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)
{
if (machine_is_collie())
ucb1x00_io_write(ts->ucb, 0, COLLIE_TC35143_GPIO_TBL_CHK);
else {
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)
{
if (machine_is_collie())
ucb1x00_io_write(ts->ucb, 0, COLLIE_TC35143_GPIO_TBL_CHK);
else {
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);
}
static inline int ucb1x00_ts_pen_down(struct ucb1x00_ts *ts)
{
unsigned int val = ucb1x00_reg_read(ts->ucb, UCB_TS_CR);
if (machine_is_collie())
return (!(val & (UCB_TS_CR_TSPX_LOW)));
else
return (val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW));
}
/*
* 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;
DECLARE_WAITQUEUE(wait, current);
int valid = 0;
set_freezable();
add_wait_queue(&ts->irq_wait, &wait);
while (!kthread_should_stop()) {
unsigned int x, y, p;
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);
if (ucb1x00_ts_pen_down(ts)) {
set_current_state(TASK_INTERRUPTIBLE);
ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, machine_is_collie() ? UCB_RISING : 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_current_state(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 = input_get_drvdata(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 = input_get_drvdata(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;
struct input_dev *idev;
int err;
ts = kzalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL);
idev = input_allocate_device();
if (!ts || !idev) {
err = -ENOMEM;
goto fail;
}
ts->ucb = dev->ucb;
ts->idev = idev;
ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC;
idev->name = "Touchscreen panel";
idev->id.product = ts->ucb->id;
idev->open = ucb1x00_ts_open;
idev->close = ucb1x00_ts_close;
__set_bit(EV_ABS, idev->evbit);
input_set_drvdata(idev, ts);
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);
input_set_abs_params(idev, ABS_X, 0, ts->x_res, 0, 0);
input_set_abs_params(idev, ABS_Y, 0, ts->y_res, 0, 0);
input_set_abs_params(idev, ABS_PRESSURE, 0, 0, 0, 0);
err = input_register_device(idev);
if (err)
goto fail;
dev->priv = ts;
return 0;
fail:
input_free_device(idev);
kfree(ts);
return err;
}
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");