From: YoungJun Cho <yj44.cho@xxxxxxxxxxx> This function can be used to set the maximum return packet size for a MIPI DSI peripheral. Signed-off-by: YoungJun Cho <yj44.cho@xxxxxxxxxxx> [treding: endianess, kerneldoc, return value] Signed-off-by: Thierry Reding <treding@xxxxxxxxxx> --- 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, -- 2.1.2 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel