2022-02-10 17:37:03

by Julien Stephan

Subject: [PATCH v2] drm/mediatek: allow commands to be sent during video mode

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.

Signed-off-by: Julien STEPHAN <[email protected]>
Signed-off-by: Mattijs Korpershoek <[email protected]>
---
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

2022-02-11 19:24:47

by Chun-Kuang Hu

Subject: Re: [PATCH v2] drm/mediatek: allow commands to be sent during video mode

Hi, Julien:

Julien STEPHAN <[email protected]> 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 <[email protected]>

>
> Signed-off-by: Julien STEPHAN <[email protected]>
> Signed-off-by: Mattijs Korpershoek <[email protected]>
> ---
> 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
>