@@ -80,6 +80,13 @@ static int max9271_pclk_detect(struct max9271_device *dev)
return -EIO;
}
+void max9271_wake_up(struct max9271_device *dev)
+{
+ i2c_smbus_read_byte(dev->client);
+ usleep_range(5000, 8000);
+}
+EXPORT_SYMBOL_GPL(max9271_wake_up);
+
int max9271_set_serial_link(struct max9271_device *dev, bool enable)
{
int ret;
@@ -85,6 +85,15 @@ struct max9271_device {
struct i2c_client *client;
};
+/**
+ * max9271_wake_up() - Wake up the serializer by issuing an i2c transaction
+ * @dev: The max9271 device
+ *
+ * This function shall be called before any other interaction with the
+ * serializer.
+ */
+void max9271_wake_up(struct max9271_device *dev);
+
/**
* max9271_set_serial_link() - Enable/disable serial link
* @dev: The max9271 device
@@ -459,7 +459,7 @@ static int rdacm20_initialize(struct rdacm20_device *dev)
/* Verify communication with the MAX9271: ping to wakeup. */
dev->serializer.client->addr = MAX9271_DEFAULT_ADDR;
- i2c_smbus_read_byte(dev->serializer.client);
+ max9271_wake_up(&dev->serializer);
/* Serial link disabled during config as it needs a valid pixel clock. */
ret = max9271_set_serial_link(&dev->serializer, false);
@@ -452,8 +452,7 @@ static int rdacm21_initialize(struct rdacm21_device *dev)
/* Verify communication with the MAX9271: ping to wakeup. */
dev->serializer.client->addr = MAX9271_DEFAULT_ADDR;
- i2c_smbus_read_byte(dev->serializer.client);
- usleep_range(3000, 5000);
+ max9271_wake_up(&dev->serializer);
/* Enable reverse channel and disable the serial link. */
ret = max9271_set_serial_link(&dev->serializer, false);
The MAX9271 chip manual prescribes a delay of 5 milliseconds after the chip exists from low power state. Add a new function to the max9271 library driver that wakes up the chip with a dummy i2c transaction and implements the correct delay of 5 milliseconds after the chip exits from low power state. Use the newly introduced function in the rdacm20 and rdacm21 camera drivers. The former was not respecting the required delay while the latter was waiting for a too-short timeout. Do not handle the initial i2c address configuration in the library driver function as the camera module drivers control address reprogramming. Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org> --- drivers/media/i2c/max9271.c | 7 +++++++ drivers/media/i2c/max9271.h | 9 +++++++++ drivers/media/i2c/rdacm20.c | 2 +- drivers/media/i2c/rdacm21.c | 3 +-- 4 files changed, 18 insertions(+), 3 deletions(-)