diff options
Diffstat (limited to 'drivers/gpio/pca953x.c')
| -rw-r--r-- | drivers/gpio/pca953x.c | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/drivers/gpio/pca953x.c b/drivers/gpio/pca953x.c index 694b0f9c4b6c..2fc25dec7cf5 100644 --- a/drivers/gpio/pca953x.c +++ b/drivers/gpio/pca953x.c @@ -60,6 +60,7 @@ 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; @@ -119,13 +120,17 @@ static int pca953x_gpio_direction_input(struct gpio_chip *gc, unsigned off) 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) - return ret; + goto exit; chip->reg_direction = reg_val; - return 0; + ret = 0; +exit: + mutex_unlock(&chip->i2c_lock); + return ret; } static int pca953x_gpio_direction_output(struct gpio_chip *gc, @@ -137,6 +142,7 @@ static int pca953x_gpio_direction_output(struct gpio_chip *gc, 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); @@ -145,7 +151,7 @@ static int pca953x_gpio_direction_output(struct gpio_chip *gc, ret = pca953x_write_reg(chip, PCA953X_OUTPUT, reg_val); if (ret) - return ret; + goto exit; chip->reg_output = reg_val; @@ -153,10 +159,13 @@ static int pca953x_gpio_direction_output(struct gpio_chip *gc, reg_val = chip->reg_direction & ~(1u << off); ret = pca953x_write_reg(chip, PCA953X_DIRECTION, reg_val); if (ret) - return ret; + goto exit; chip->reg_direction = reg_val; - return 0; + ret = 0; +exit: + mutex_unlock(&chip->i2c_lock); + return ret; } static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off) @@ -167,7 +176,9 @@ static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off) chip = container_of(gc, struct pca953x_chip, gpio_chip); + mutex_lock(&chip->i2c_lock); ret = pca953x_read_reg(chip, PCA953X_INPUT, ®_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 @@ -187,6 +198,7 @@ static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val) chip = container_of(gc, struct pca953x_chip, gpio_chip); + mutex_lock(&chip->i2c_lock); if (val) reg_val = chip->reg_output | (1u << off); else @@ -194,9 +206,11 @@ static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val) ret = pca953x_write_reg(chip, PCA953X_OUTPUT, reg_val); if (ret) - return; + goto exit; chip->reg_output = reg_val; +exit: + mutex_unlock(&chip->i2c_lock); } static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios) @@ -518,6 +532,8 @@ static int __devinit pca953x_probe(struct i2c_client *client, 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. */ |