diff options
Diffstat (limited to 'io-module/gpio.c')
| -rw-r--r-- | io-module/gpio.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/io-module/gpio.c b/io-module/gpio.c index 0b45300..e754ed6 100644 --- a/io-module/gpio.c +++ b/io-module/gpio.c @@ -44,6 +44,14 @@ struct gpio_pin *gpio_pin_by_attr_name(const char *name) { return NULL; } +/* Any gpio that could potentially get routed over an i2c bus + * as opposed to a memory write to a register must call + * "cansleep" versions of gpio functions. The purpose of the + * function is to remind kernel driver writers that any GPIO + * routed over i2c (or spi) cannot be accessed in an interrupt + * handler. Interrupt handlers should use the GPIO pins + * that are memory mapped. gpio_get_value and gpio_set_value + * cannot be used with the PCA 9557 or a dump will result. */ ssize_t mts_attr_show_gpio_pin(struct device *dev, struct device_attribute *attr, char *buf) @@ -57,7 +65,7 @@ ssize_t mts_attr_show_gpio_pin(struct device *dev, mutex_lock(&mts_io_mutex); - value = gpio_get_value(pin->pin.gpio); + value = gpio_get_value_cansleep(pin->pin.gpio); mutex_unlock(&mts_io_mutex); @@ -92,7 +100,7 @@ static ssize_t mts_attr_store_gpio_pin(struct device *dev, mutex_lock(&mts_io_mutex); - gpio_set_value(pin->pin.gpio, value); + gpio_set_value_cansleep(pin->pin.gpio, value); mutex_unlock(&mts_io_mutex); @@ -105,11 +113,11 @@ static int reset_gpio_pin(struct gpio_pin *pin, unsigned int delay_ms, unsigned return -ENODEV; } - gpio_set_value(pin->pin.gpio, value); + gpio_set_value_cansleep(pin->pin.gpio, value); mdelay(delay_ms); - gpio_set_value(pin->pin.gpio, !value); + gpio_set_value_cansleep(pin->pin.gpio, !value); return 0; } |