Hi, Julien:
Julien STEPHAN <jstephan@xxxxxxxxxxxx> 於 2022年2月10日 週四 下午8:47寫道：
>
> Mipi dsi panel drivers can use mipi_dsi_dcs_{set,get}_display_brightness()
> to request backlight changes.
>
> This can be done during panel initialization (dsi is in command mode)
> or afterwards (dsi is in Video Mode).
>
> When the DSI is in Video Mode, all commands are rejected.
>
> Detect current DSI mode in mtk_dsi_host_transfer() and switch modes
> temporarily to allow commands to be sent.
Reviewed-by: Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx>
>
> Signed-off-by: Julien STEPHAN <jstephan@xxxxxxxxxxxx>
> Signed-off-by: Mattijs Korpershoek <mkorpershoek@xxxxxxxxxxxx>
> ---
> Changes in v2:
> - update commit message to be more descriptive
>
> drivers/gpu/drm/mediatek/mtk_dsi.c | 34 ++++++++++++++++++++++--------
> 1 file changed, 25 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index 5d90d2eb0019..7d66fdc7f81d 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -891,24 +891,34 @@ static ssize_t mtk_dsi_host_transfer(struct mipi_dsi_host *host,
> u8 read_data[16];
> void *src_addr;
> u8 irq_flag = CMD_DONE_INT_FLAG;
> -
> - if (readl(dsi->regs + DSI_MODE_CTRL) & MODE) {
> - DRM_ERROR("dsi engine is not command mode\n");
> - return -EINVAL;
> + u32 dsi_mode;
> +
> + dsi_mode = readl(dsi->regs + DSI_MODE_CTRL);
> + if (dsi_mode & MODE) {
> + mtk_dsi_stop(dsi);
> + if (mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500)) {
> + recv_cnt = -EINVAL;
> + goto restore_dsi_mode;
> + }
> }
>
> if (MTK_DSI_HOST_IS_READ(msg->type))
> irq_flag |= LPRX_RD_RDY_INT_FLAG;
>
> - if (mtk_dsi_host_send_cmd(dsi, msg, irq_flag) < 0)
> - return -ETIME;
> + if (mtk_dsi_host_send_cmd(dsi, msg, irq_flag) < 0) {
> + recv_cnt = -ETIME;
> + goto restore_dsi_mode;
> + }
>
> - if (!MTK_DSI_HOST_IS_READ(msg->type))
> - return 0;
> + if (!MTK_DSI_HOST_IS_READ(msg->type)) {
> + recv_cnt = 0;
> + goto restore_dsi_mode;
> + }
>
> if (!msg->rx_buf) {
> DRM_ERROR("dsi receive buffer size may be NULL\n");
> - return -EINVAL;
> + recv_cnt = -EINVAL;
> + goto restore_dsi_mode;
> }
>
> for (i = 0; i < 16; i++)
> @@ -933,6 +943,12 @@ static ssize_t mtk_dsi_host_transfer(struct mipi_dsi_host *host,
> DRM_INFO("dsi get %d byte data from the panel address(0x%x)\n",
> recv_cnt, *((u8 *)(msg->tx_buf)));
>
> +restore_dsi_mode:
> + if (dsi_mode & MODE) {
> + mtk_dsi_set_mode(dsi);
> + mtk_dsi_start(dsi);
> + }
> +
> return recv_cnt;
> }
>
> --
> 2.35.1
>
