MTCDT-0.2 with PCA9557 support

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;
 }