From: YoungJun Cho yj44.cho@samsung.com
This function can be used to set the maximum return packet size for a MIPI DSI peripheral.
Signed-off-by: YoungJun Cho yj44.cho@samsung.com [treding: endianess, kerneldoc, return value] Signed-off-by: Thierry Reding treding@nvidia.com --- drivers/gpu/drm/drm_mipi_dsi.c | 30 ++++++++++++++++++++++++++++++ include/drm/drm_mipi_dsi.h | 2 ++ 2 files changed, 32 insertions(+)
diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c index 1702ffd07986..27fc6dac5e4a 100644 --- a/drivers/gpu/drm/drm_mipi_dsi.c +++ b/drivers/gpu/drm/drm_mipi_dsi.c @@ -198,6 +198,36 @@ int mipi_dsi_detach(struct mipi_dsi_device *dsi) } EXPORT_SYMBOL(mipi_dsi_detach);
+/* + * mipi_dsi_set_maximum_return_packet_size() - specify the maximum size of the + * the payload in a long packet transmitted from the peripheral back to the + * host processor + * @dsi: DSI peripheral device + * @value: the maximum size of the payload + * + * Return: 0 on success or a negative error code on failure. + */ +int mipi_dsi_set_maximum_return_packet_size(struct mipi_dsi_device *dsi, + u16 value) +{ + u8 tx[2] = { value & 0xff, value >> 8 }; + struct mipi_dsi_msg msg; + ssize_t err; + + memset(&msg, 0, sizeof(msg)); + msg.channel = dsi->channel; + msg.type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE; + msg.tx_len = sizeof(tx); + msg.tx_buf = tx; + + err = dsi->host->ops->transfer(dsi->host, &msg); + if (err < 0) + return err; + + return 0; +} +EXPORT_SYMBOL(mipi_dsi_set_maximum_return_packet_size); + /** * mipi_dsi_dcs_write_buffer() - transmit a DCS command with payload * @dsi: DSI peripheral device diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h index 836cc2b677d0..ef50b5d0de57 100644 --- a/include/drm/drm_mipi_dsi.h +++ b/include/drm/drm_mipi_dsi.h @@ -132,6 +132,8 @@ static inline struct mipi_dsi_device *to_mipi_dsi_device(struct device *dev)
int mipi_dsi_attach(struct mipi_dsi_device *dsi); int mipi_dsi_detach(struct mipi_dsi_device *dsi); +int mipi_dsi_set_maximum_return_packet_size(struct mipi_dsi_device *dsi, + u16 value); ssize_t mipi_dsi_dcs_write_buffer(struct mipi_dsi_device *dsi, const void *data, size_t len); ssize_t mipi_dsi_dcs_write(struct mipi_dsi_device *dsi, u8 cmd,