linux/drivers/gpio/pca953x.c
Ben Dooks 272df502bc gpio/pca953x: fix error handling path in probe() call
If the device fails to respond, then the error path tries to remove an
interrupt that never got registered, which causes an backtrace from the
interrupt handling code.

Fix this by ensuring that the cleanup path has two labels and use the
correct path as needed.

fixes the following error:

WARNING: at kernel/irq/manage.c:908 __free_irq+0x80/0x160()
Trying to free already-free IRQ 0

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-03-30 21:28:12 -06:00

637 lines
14 KiB
C

/*
* pca953x.c - 4/8/16 bit I/O ports
*
* Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com>
* Copyright (C) 2007 Marvell International Ltd.
*
* Derived from drivers/i2c/chips/pca9539.c
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/i2c.h>
#include <linux/i2c/pca953x.h>
#include <linux/slab.h>
#ifdef CONFIG_OF_GPIO
#include <linux/of_platform.h>
#include <linux/of_gpio.h>
#endif
#define PCA953X_INPUT 0
#define PCA953X_OUTPUT 1
#define PCA953X_INVERT 2
#define PCA953X_DIRECTION 3
#define PCA953X_GPIOS 0x00FF
#define PCA953X_INT 0x0100
static const struct i2c_device_id pca953x_id[] = {
{ "pca9534", 8 | PCA953X_INT, },
{ "pca9535", 16 | PCA953X_INT, },
{ "pca9536", 4, },
{ "pca9537", 4 | PCA953X_INT, },
{ "pca9538", 8 | PCA953X_INT, },
{ "pca9539", 16 | PCA953X_INT, },
{ "pca9554", 8 | PCA953X_INT, },
{ "pca9555", 16 | PCA953X_INT, },
{ "pca9556", 8, },
{ "pca9557", 8, },
{ "max7310", 8, },
{ "max7312", 16 | PCA953X_INT, },
{ "max7313", 16 | PCA953X_INT, },
{ "max7315", 8 | PCA953X_INT, },
{ "pca6107", 8 | PCA953X_INT, },
{ "tca6408", 8 | PCA953X_INT, },
{ "tca6416", 16 | PCA953X_INT, },
/* NYET: { "tca6424", 24, }, */
{ }
};
MODULE_DEVICE_TABLE(i2c, pca953x_id);
struct pca953x_chip {
unsigned gpio_start;
uint16_t reg_output;
uint16_t reg_direction;
struct mutex i2c_lock;
#ifdef CONFIG_GPIO_PCA953X_IRQ
struct mutex irq_lock;
uint16_t irq_mask;
uint16_t irq_stat;
uint16_t irq_trig_raise;
uint16_t irq_trig_fall;
int irq_base;
#endif
struct i2c_client *client;
struct pca953x_platform_data *dyn_pdata;
struct gpio_chip gpio_chip;
const char *const *names;
};
static int pca953x_write_reg(struct pca953x_chip *chip, int reg, uint16_t val)
{
int ret;
if (chip->gpio_chip.ngpio <= 8)
ret = i2c_smbus_write_byte_data(chip->client, reg, val);
else
ret = i2c_smbus_write_word_data(chip->client, reg << 1, val);
if (ret < 0) {
dev_err(&chip->client->dev, "failed writing register\n");
return ret;
}
return 0;
}
static int pca953x_read_reg(struct pca953x_chip *chip, int reg, uint16_t *val)
{
int ret;
if (chip->gpio_chip.ngpio <= 8)
ret = i2c_smbus_read_byte_data(chip->client, reg);
else
ret = i2c_smbus_read_word_data(chip->client, reg << 1);
if (ret < 0) {
dev_err(&chip->client->dev, "failed reading register\n");
return ret;
}
*val = (uint16_t)ret;
return 0;
}
static int pca953x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
{
struct pca953x_chip *chip;
uint16_t reg_val;
int ret;
chip = container_of(gc, struct pca953x_chip, gpio_chip);
mutex_lock(&chip->i2c_lock);
reg_val = chip->reg_direction | (1u << off);
ret = pca953x_write_reg(chip, PCA953X_DIRECTION, reg_val);
if (ret)
goto exit;
chip->reg_direction = reg_val;
ret = 0;
exit:
mutex_unlock(&chip->i2c_lock);
return ret;
}
static int pca953x_gpio_direction_output(struct gpio_chip *gc,
unsigned off, int val)
{
struct pca953x_chip *chip;
uint16_t reg_val;
int ret;
chip = container_of(gc, struct pca953x_chip, gpio_chip);
mutex_lock(&chip->i2c_lock);
/* set output level */
if (val)
reg_val = chip->reg_output | (1u << off);
else
reg_val = chip->reg_output & ~(1u << off);
ret = pca953x_write_reg(chip, PCA953X_OUTPUT, reg_val);
if (ret)
goto exit;
chip->reg_output = reg_val;
/* then direction */
reg_val = chip->reg_direction & ~(1u << off);
ret = pca953x_write_reg(chip, PCA953X_DIRECTION, reg_val);
if (ret)
goto exit;
chip->reg_direction = reg_val;
ret = 0;
exit:
mutex_unlock(&chip->i2c_lock);
return ret;
}
static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
{
struct pca953x_chip *chip;
uint16_t reg_val;
int ret;
chip = container_of(gc, struct pca953x_chip, gpio_chip);
mutex_lock(&chip->i2c_lock);
ret = pca953x_read_reg(chip, PCA953X_INPUT, &reg_val);
mutex_unlock(&chip->i2c_lock);
if (ret < 0) {
/* NOTE: diagnostic already emitted; that's all we should
* do unless gpio_*_value_cansleep() calls become different
* from their nonsleeping siblings (and report faults).
*/
return 0;
}
return (reg_val & (1u << off)) ? 1 : 0;
}
static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
{
struct pca953x_chip *chip;
uint16_t reg_val;
int ret;
chip = container_of(gc, struct pca953x_chip, gpio_chip);
mutex_lock(&chip->i2c_lock);
if (val)
reg_val = chip->reg_output | (1u << off);
else
reg_val = chip->reg_output & ~(1u << off);
ret = pca953x_write_reg(chip, PCA953X_OUTPUT, reg_val);
if (ret)
goto exit;
chip->reg_output = reg_val;
exit:
mutex_unlock(&chip->i2c_lock);
}
static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
{
struct gpio_chip *gc;
gc = &chip->gpio_chip;
gc->direction_input = pca953x_gpio_direction_input;
gc->direction_output = pca953x_gpio_direction_output;
gc->get = pca953x_gpio_get_value;
gc->set = pca953x_gpio_set_value;
gc->can_sleep = 1;
gc->base = chip->gpio_start;
gc->ngpio = gpios;
gc->label = chip->client->name;
gc->dev = &chip->client->dev;
gc->owner = THIS_MODULE;
gc->names = chip->names;
}
#ifdef CONFIG_GPIO_PCA953X_IRQ
static int pca953x_gpio_to_irq(struct gpio_chip *gc, unsigned off)
{
struct pca953x_chip *chip;
chip = container_of(gc, struct pca953x_chip, gpio_chip);
return chip->irq_base + off;
}
static void pca953x_irq_mask(struct irq_data *d)
{
struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
chip->irq_mask &= ~(1 << (d->irq - chip->irq_base));
}
static void pca953x_irq_unmask(struct irq_data *d)
{
struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
chip->irq_mask |= 1 << (d->irq - chip->irq_base);
}
static void pca953x_irq_bus_lock(struct irq_data *d)
{
struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
mutex_lock(&chip->irq_lock);
}
static void pca953x_irq_bus_sync_unlock(struct irq_data *d)
{
struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
uint16_t new_irqs;
uint16_t level;
/* Look for any newly setup interrupt */
new_irqs = chip->irq_trig_fall | chip->irq_trig_raise;
new_irqs &= ~chip->reg_direction;
while (new_irqs) {
level = __ffs(new_irqs);
pca953x_gpio_direction_input(&chip->gpio_chip, level);
new_irqs &= ~(1 << level);
}
mutex_unlock(&chip->irq_lock);
}
static int pca953x_irq_set_type(struct irq_data *d, unsigned int type)
{
struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
uint16_t level = d->irq - chip->irq_base;
uint16_t mask = 1 << level;
if (!(type & IRQ_TYPE_EDGE_BOTH)) {
dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
d->irq, type);
return -EINVAL;
}
if (type & IRQ_TYPE_EDGE_FALLING)
chip->irq_trig_fall |= mask;
else
chip->irq_trig_fall &= ~mask;
if (type & IRQ_TYPE_EDGE_RISING)
chip->irq_trig_raise |= mask;
else
chip->irq_trig_raise &= ~mask;
return 0;
}
static struct irq_chip pca953x_irq_chip = {
.name = "pca953x",
.irq_mask = pca953x_irq_mask,
.irq_unmask = pca953x_irq_unmask,
.irq_bus_lock = pca953x_irq_bus_lock,
.irq_bus_sync_unlock = pca953x_irq_bus_sync_unlock,
.irq_set_type = pca953x_irq_set_type,
};
static uint16_t pca953x_irq_pending(struct pca953x_chip *chip)
{
uint16_t cur_stat;
uint16_t old_stat;
uint16_t pending;
uint16_t trigger;
int ret;
ret = pca953x_read_reg(chip, PCA953X_INPUT, &cur_stat);
if (ret)
return 0;
/* Remove output pins from the equation */
cur_stat &= chip->reg_direction;
old_stat = chip->irq_stat;
trigger = (cur_stat ^ old_stat) & chip->irq_mask;
if (!trigger)
return 0;
chip->irq_stat = cur_stat;
pending = (old_stat & chip->irq_trig_fall) |
(cur_stat & chip->irq_trig_raise);
pending &= trigger;
return pending;
}
static irqreturn_t pca953x_irq_handler(int irq, void *devid)
{
struct pca953x_chip *chip = devid;
uint16_t pending;
uint16_t level;
pending = pca953x_irq_pending(chip);
if (!pending)
return IRQ_HANDLED;
do {
level = __ffs(pending);
generic_handle_irq(level + chip->irq_base);
pending &= ~(1 << level);
} while (pending);
return IRQ_HANDLED;
}
static int pca953x_irq_setup(struct pca953x_chip *chip,
const struct i2c_device_id *id)
{
struct i2c_client *client = chip->client;
struct pca953x_platform_data *pdata = client->dev.platform_data;
int ret;
if (pdata->irq_base != -1
&& (id->driver_data & PCA953X_INT)) {
int lvl;
ret = pca953x_read_reg(chip, PCA953X_INPUT,
&chip->irq_stat);
if (ret)
goto out_failed;
/*
* There is no way to know which GPIO line generated the
* interrupt. We have to rely on the previous read for
* this purpose.
*/
chip->irq_stat &= chip->reg_direction;
chip->irq_base = pdata->irq_base;
mutex_init(&chip->irq_lock);
for (lvl = 0; lvl < chip->gpio_chip.ngpio; lvl++) {
int irq = lvl + chip->irq_base;
irq_set_chip_data(irq, chip);
irq_set_chip_and_handler(irq, &pca953x_irq_chip,
handle_edge_irq);
#ifdef CONFIG_ARM
set_irq_flags(irq, IRQF_VALID);
#else
irq_set_noprobe(irq);
#endif
}
ret = request_threaded_irq(client->irq,
NULL,
pca953x_irq_handler,
IRQF_TRIGGER_RISING |
IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
dev_name(&client->dev), chip);
if (ret) {
dev_err(&client->dev, "failed to request irq %d\n",
client->irq);
goto out_failed;
}
chip->gpio_chip.to_irq = pca953x_gpio_to_irq;
}
return 0;
out_failed:
chip->irq_base = -1;
return ret;
}
static void pca953x_irq_teardown(struct pca953x_chip *chip)
{
if (chip->irq_base != -1)
free_irq(chip->client->irq, chip);
}
#else /* CONFIG_GPIO_PCA953X_IRQ */
static int pca953x_irq_setup(struct pca953x_chip *chip,
const struct i2c_device_id *id)
{
struct i2c_client *client = chip->client;
struct pca953x_platform_data *pdata = client->dev.platform_data;
if (pdata->irq_base != -1 && (id->driver_data & PCA953X_INT))
dev_warn(&client->dev, "interrupt support not compiled in\n");
return 0;
}
static void pca953x_irq_teardown(struct pca953x_chip *chip)
{
}
#endif
/*
* Handlers for alternative sources of platform_data
*/
#ifdef CONFIG_OF_GPIO
/*
* Translate OpenFirmware node properties into platform_data
*/
static struct pca953x_platform_data *
pca953x_get_alt_pdata(struct i2c_client *client)
{
struct pca953x_platform_data *pdata;
struct device_node *node;
const __be32 *val;
int size;
node = client->dev.of_node;
if (node == NULL)
return NULL;
pdata = kzalloc(sizeof(struct pca953x_platform_data), GFP_KERNEL);
if (pdata == NULL) {
dev_err(&client->dev, "Unable to allocate platform_data\n");
return NULL;
}
pdata->gpio_base = -1;
val = of_get_property(node, "linux,gpio-base", &size);
if (val) {
if (size != sizeof(*val))
dev_warn(&client->dev, "%s: wrong linux,gpio-base\n",
node->full_name);
else
pdata->gpio_base = be32_to_cpup(val);
}
val = of_get_property(node, "polarity", NULL);
if (val)
pdata->invert = *val;
return pdata;
}
#else
static struct pca953x_platform_data *
pca953x_get_alt_pdata(struct i2c_client *client)
{
return NULL;
}
#endif
static int __devinit pca953x_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct pca953x_platform_data *pdata;
struct pca953x_chip *chip;
int ret;
chip = kzalloc(sizeof(struct pca953x_chip), GFP_KERNEL);
if (chip == NULL)
return -ENOMEM;
pdata = client->dev.platform_data;
if (pdata == NULL) {
pdata = pca953x_get_alt_pdata(client);
/*
* Unlike normal platform_data, this is allocated
* dynamically and must be freed in the driver
*/
chip->dyn_pdata = pdata;
}
if (pdata == NULL) {
dev_dbg(&client->dev, "no platform data\n");
ret = -EINVAL;
goto out_failed;
}
chip->client = client;
chip->gpio_start = pdata->gpio_base;
chip->names = pdata->names;
mutex_init(&chip->i2c_lock);
/* initialize cached registers from their original values.
* we can't share this chip with another i2c master.
*/
pca953x_setup_gpio(chip, id->driver_data & PCA953X_GPIOS);
ret = pca953x_read_reg(chip, PCA953X_OUTPUT, &chip->reg_output);
if (ret)
goto out_failed;
ret = pca953x_read_reg(chip, PCA953X_DIRECTION, &chip->reg_direction);
if (ret)
goto out_failed;
/* set platform specific polarity inversion */
ret = pca953x_write_reg(chip, PCA953X_INVERT, pdata->invert);
if (ret)
goto out_failed;
ret = pca953x_irq_setup(chip, id);
if (ret)
goto out_failed;
ret = gpiochip_add(&chip->gpio_chip);
if (ret)
goto out_failed_irq;
if (pdata->setup) {
ret = pdata->setup(client, chip->gpio_chip.base,
chip->gpio_chip.ngpio, pdata->context);
if (ret < 0)
dev_warn(&client->dev, "setup failed, %d\n", ret);
}
i2c_set_clientdata(client, chip);
return 0;
out_failed_irq:
pca953x_irq_teardown(chip);
out_failed:
kfree(chip->dyn_pdata);
kfree(chip);
return ret;
}
static int pca953x_remove(struct i2c_client *client)
{
struct pca953x_platform_data *pdata = client->dev.platform_data;
struct pca953x_chip *chip = i2c_get_clientdata(client);
int ret = 0;
if (pdata->teardown) {
ret = pdata->teardown(client, chip->gpio_chip.base,
chip->gpio_chip.ngpio, pdata->context);
if (ret < 0) {
dev_err(&client->dev, "%s failed, %d\n",
"teardown", ret);
return ret;
}
}
ret = gpiochip_remove(&chip->gpio_chip);
if (ret) {
dev_err(&client->dev, "%s failed, %d\n",
"gpiochip_remove()", ret);
return ret;
}
pca953x_irq_teardown(chip);
kfree(chip->dyn_pdata);
kfree(chip);
return 0;
}
static struct i2c_driver pca953x_driver = {
.driver = {
.name = "pca953x",
},
.probe = pca953x_probe,
.remove = pca953x_remove,
.id_table = pca953x_id,
};
static int __init pca953x_init(void)
{
return i2c_add_driver(&pca953x_driver);
}
/* register after i2c postcore initcall and before
* subsys initcalls that may rely on these GPIOs
*/
subsys_initcall(pca953x_init);
static void __exit pca953x_exit(void)
{
i2c_del_driver(&pca953x_driver);
}
module_exit(pca953x_exit);
MODULE_AUTHOR("eric miao <eric.miao@marvell.com>");
MODULE_DESCRIPTION("GPIO expander driver for PCA953x");
MODULE_LICENSE("GPL");