linux/drivers/gpio/gpio-max730x.c
Christophe Leroy 6f4deb18a5 gpio: max730x: set gpiochip data pointer before using it
gpiochip_add_data() has to be called before calling
max7301_direction_input()

[    4.389883] Unable to handle kernel paging request for data at address 0x00000018
[    4.397282] Faulting instruction address: 0xc01a8cbc
[    4.402023] Oops: Kernel access of bad area, sig: 11 [#1]
[    4.407331] PREEMPT CMPC885
[    4.410131] CPU: 0 PID: 6 Comm: kworker/u2:0 Not tainted 4.5.0-gacdfdee #39
[    4.418592] Workqueue: deferwq deferred_probe_work_func
[    4.423711] task: c60798b0 ti: c608a000 task.ti: c608a000
[    4.429038] NIP: c01a8cbc LR: c01a8e24 CTR: c01ff028
[    4.433953] REGS: c608bad0 TRAP: 0300   Not tainted  (4.5.0-s3k-dev-gacdfdee-svn-dirty)
[    4.441847] MSR: 00009032 <EE,ME,IR,DR,RI>  CR: 33039553  XER: a000f940
[    4.448395] DAR: 00000018 DSISR: c0000000
GPR00: c01a8e24 c608bb80 c60798b0 c60d6f6c 00000004 00000002 07de2900 00700000
GPR08: 00000000 00000000 c608a000 00001032 35039553 00000000 c002f37c c6010b64
GPR16: c6010a48 c6010a14 c6010a00 00000000 c0450000 c0453568 c0453438 c050db14
GPR24: c62662bc 00000009 ffffffaa c60d6f5d 00000001 00000000 00000000 00000000
[    4.480371] NIP [c01a8cbc] max7301_direction_input+0x20/0x9c
[    4.485951] LR [c01a8e24] __max730x_probe+0xec/0x138
[    4.490812] Call Trace:
[    4.493268] [c608bba0] [c01a8e24] __max730x_probe+0xec/0x138
[    4.498878] [c608bbc0] [c01cc368] driver_probe_device+0x190/0x38c
[    4.504895] [c608bbf0] [c01ca918] bus_for_each_drv+0x58/0xb4
[    4.510489] [c608bc20] [c01cc04c] __device_attach+0x8c/0x110
[    4.516082] [c608bc50] [c01cab80] bus_probe_device+0x34/0xb8
[    4.521673] [c608bc70] [c01c96c8] device_add+0x3c0/0x598
[    4.526925] [c608bcb0] [c0200f90] spi_add_device+0x114/0x160
[    4.532512] [c608bcd0] [c02018d0] spi_register_master+0x6e0/0x7c8
[    4.538537] [c608bd20] [c02019fc] devm_spi_register_master+0x44/0x8c
[    4.544824] [c608bd40] [c0203854] of_fsl_spi_probe+0x458/0x57c
[    4.550587] [c608bda0] [c01cd828] platform_drv_probe+0x30/0x74
[    4.556366] [c608bdb0] [c01cc368] driver_probe_device+0x190/0x38c
[    4.562383] [c608bde0] [c01ca918] bus_for_each_drv+0x58/0xb4
[    4.567977] [c608be10] [c01cc04c] __device_attach+0x8c/0x110
[    4.573572] [c608be40] [c01cab80] bus_probe_device+0x34/0xb8
[    4.579170] [c608be60] [c01cb9b4] deferred_probe_work_func+0xa4/0xc4
[    4.585438] [c608be80] [c0029c04] process_one_work+0x22c/0x414
[    4.591201] [c608bea0] [c002a100] worker_thread+0x314/0x5c0
[    4.596722] [c608bef0] [c002f444] kthread+0xc8/0xcc
[    4.601538] [c608bf40] [c000af84] ret_from_kernel_thread+0x5c/0x64
[    4.607596] Instruction dump:
[    4.610530] 7c0803a6 bba10014 38210020 4e800020 7c0802a6 9421ffe0 38840004 bf810010
[    4.618188] 90010024 549cf0be 83c30010 549d0f7c <813e0018> 7fc3f378 7d3f2430 57ff07fe
[    4.626041] ---[ end trace 303adb021dd4caf2 ]---

Cc: stable@vger.kernel.org
fixes: 5e45e01916 ("gpio: max730x: use gpiochip data pointer")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-08-10 15:40:44 +02:00

246 lines
5.8 KiB
C

/**
* Copyright (C) 2006 Juergen Beisert, Pengutronix
* Copyright (C) 2008 Guennadi Liakhovetski, Pengutronix
* Copyright (C) 2009 Wolfram Sang, Pengutronix
*
* 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.
*
* The Maxim MAX7300/1 device is an I2C/SPI driven GPIO expander. There are
* 28 GPIOs. 8 of them can trigger an interrupt. See datasheet for more
* details
* Note:
* - DIN must be stable at the rising edge of clock.
* - when writing:
* - always clock in 16 clocks at once
* - at DIN: D15 first, D0 last
* - D0..D7 = databyte, D8..D14 = commandbyte
* - D15 = low -> write command
* - when reading
* - always clock in 16 clocks at once
* - at DIN: D15 first, D0 last
* - D0..D7 = dummy, D8..D14 = register address
* - D15 = high -> read command
* - raise CS and assert it again
* - always clock in 16 clocks at once
* - at DOUT: D15 first, D0 last
* - D0..D7 contains the data from the first cycle
*
* The driver exports a standard gpiochip interface
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/spi/max7301.h>
#include <linux/gpio.h>
#include <linux/slab.h>
/*
* Pin configurations, see MAX7301 datasheet page 6
*/
#define PIN_CONFIG_MASK 0x03
#define PIN_CONFIG_IN_PULLUP 0x03
#define PIN_CONFIG_IN_WO_PULLUP 0x02
#define PIN_CONFIG_OUT 0x01
#define PIN_NUMBER 28
static int max7301_direction_input(struct gpio_chip *chip, unsigned offset)
{
struct max7301 *ts = gpiochip_get_data(chip);
u8 *config;
u8 offset_bits, pin_config;
int ret;
/* First 4 pins are unused in the controller */
offset += 4;
offset_bits = (offset & 3) << 1;
config = &ts->port_config[offset >> 2];
if (ts->input_pullup_active & BIT(offset))
pin_config = PIN_CONFIG_IN_PULLUP;
else
pin_config = PIN_CONFIG_IN_WO_PULLUP;
mutex_lock(&ts->lock);
*config = (*config & ~(PIN_CONFIG_MASK << offset_bits))
| (pin_config << offset_bits);
ret = ts->write(ts->dev, 0x08 + (offset >> 2), *config);
mutex_unlock(&ts->lock);
return ret;
}
static int __max7301_set(struct max7301 *ts, unsigned offset, int value)
{
if (value) {
ts->out_level |= 1 << offset;
return ts->write(ts->dev, 0x20 + offset, 0x01);
} else {
ts->out_level &= ~(1 << offset);
return ts->write(ts->dev, 0x20 + offset, 0x00);
}
}
static int max7301_direction_output(struct gpio_chip *chip, unsigned offset,
int value)
{
struct max7301 *ts = gpiochip_get_data(chip);
u8 *config;
u8 offset_bits;
int ret;
/* First 4 pins are unused in the controller */
offset += 4;
offset_bits = (offset & 3) << 1;
config = &ts->port_config[offset >> 2];
mutex_lock(&ts->lock);
*config = (*config & ~(PIN_CONFIG_MASK << offset_bits))
| (PIN_CONFIG_OUT << offset_bits);
ret = __max7301_set(ts, offset, value);
if (!ret)
ret = ts->write(ts->dev, 0x08 + (offset >> 2), *config);
mutex_unlock(&ts->lock);
return ret;
}
static int max7301_get(struct gpio_chip *chip, unsigned offset)
{
struct max7301 *ts = gpiochip_get_data(chip);
int config, level = -EINVAL;
/* First 4 pins are unused in the controller */
offset += 4;
mutex_lock(&ts->lock);
config = (ts->port_config[offset >> 2] >> ((offset & 3) << 1))
& PIN_CONFIG_MASK;
switch (config) {
case PIN_CONFIG_OUT:
/* Output: return cached level */
level = !!(ts->out_level & (1 << offset));
break;
case PIN_CONFIG_IN_WO_PULLUP:
case PIN_CONFIG_IN_PULLUP:
/* Input: read out */
level = ts->read(ts->dev, 0x20 + offset) & 0x01;
}
mutex_unlock(&ts->lock);
return level;
}
static void max7301_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct max7301 *ts = gpiochip_get_data(chip);
/* First 4 pins are unused in the controller */
offset += 4;
mutex_lock(&ts->lock);
__max7301_set(ts, offset, value);
mutex_unlock(&ts->lock);
}
int __max730x_probe(struct max7301 *ts)
{
struct device *dev = ts->dev;
struct max7301_platform_data *pdata;
int i, ret;
pdata = dev_get_platdata(dev);
mutex_init(&ts->lock);
dev_set_drvdata(dev, ts);
/* Power up the chip and disable IRQ output */
ts->write(dev, 0x04, 0x01);
if (pdata) {
ts->input_pullup_active = pdata->input_pullup_active;
ts->chip.base = pdata->base;
} else {
ts->chip.base = -1;
}
ts->chip.label = dev->driver->name;
ts->chip.direction_input = max7301_direction_input;
ts->chip.get = max7301_get;
ts->chip.direction_output = max7301_direction_output;
ts->chip.set = max7301_set;
ts->chip.ngpio = PIN_NUMBER;
ts->chip.can_sleep = true;
ts->chip.parent = dev;
ts->chip.owner = THIS_MODULE;
ret = gpiochip_add_data(&ts->chip, ts);
if (ret)
goto exit_destroy;
/*
* initialize pullups according to platform data and cache the
* register values for later use.
*/
for (i = 1; i < 8; i++) {
int j;
/*
* initialize port_config with "0xAA", which means
* input with internal pullup disabled. This is needed
* to avoid writing zeros (in the inner for loop),
* which is not allowed according to the datasheet.
*/
ts->port_config[i] = 0xAA;
for (j = 0; j < 4; j++) {
int offset = (i - 1) * 4 + j;
ret = max7301_direction_input(&ts->chip, offset);
if (ret)
goto exit_destroy;
}
}
return ret;
exit_destroy:
mutex_destroy(&ts->lock);
return ret;
}
EXPORT_SYMBOL_GPL(__max730x_probe);
int __max730x_remove(struct device *dev)
{
struct max7301 *ts = dev_get_drvdata(dev);
if (ts == NULL)
return -ENODEV;
/* Power down the chip and disable IRQ output */
ts->write(dev, 0x04, 0x00);
gpiochip_remove(&ts->chip);
mutex_destroy(&ts->lock);
return 0;
}
EXPORT_SYMBOL_GPL(__max730x_remove);
MODULE_AUTHOR("Juergen Beisert, Wolfram Sang");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("MAX730x GPIO-Expanders, generic parts");