From dbf30b695809b88fd650dab4028156fb85c5f2d9 Mon Sep 17 00:00:00 2001 From: YoungJun Cho Date: Tue, 5 Aug 2014 09:27:15 +0200 Subject: [PATCH] drm/dsi: Add mipi_dsi_set_maximum_return_packet_size() helper This function can be used to set the maximum return packet size for a MIPI DSI peripheral. Signed-off-by: YoungJun Cho Reviewed-by: Sean Paul [treding: endianess, kerneldoc, return value] Signed-off-by: Thierry Reding --- drivers/gpu/drm/drm_mipi_dsi.c | 24 ++++++++++++++++++++++++ include/drm/drm_mipi_dsi.h | 2 ++ 2 files changed, 26 insertions(+) diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c index 388c3ab02500..60177a3e16be 100644 --- a/drivers/gpu/drm/drm_mipi_dsi.c +++ b/drivers/gpu/drm/drm_mipi_dsi.c @@ -332,6 +332,30 @@ int mipi_dsi_create_packet(struct mipi_dsi_packet *packet, } EXPORT_SYMBOL(mipi_dsi_create_packet); +/* + * 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 = { + .channel = dsi->channel, + .type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE, + .tx_len = sizeof(tx), + .tx_buf = tx, + }; + + return mipi_dsi_device_transfer(dsi, &msg); +} +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 4eeb4a5ead8b..4a4e9d7ccc16 100644 --- a/include/drm/drm_mipi_dsi.h +++ b/include/drm/drm_mipi_dsi.h @@ -153,6 +153,8 @@ 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, -- 2.20.1