diff mbox series

[v4,4/4] drm/mediatek: Add pull-down MIPI operation in mtk_dsi_poweroff function

Message ID 1649644308-8455-5-git-send-email-xinlei.lee@mediatek.com (mailing list archive)
State New, archived
Headers show
Series Cooperate with DSI RX devices to modify dsi funcs and delay mipi high to cooperate with panel sequence | expand

Commit Message

Xinlei Lee (李昕磊) April 11, 2022, 2:31 a.m. UTC
From: Xinlei Lee <xinlei.lee@mediatek.com>

In the dsi_enable function, mtk_dsi_rxtx_control is to
pull up the MIPI signal operation. Before dsi_disable,
MIPI should also be pulled down by writing a register 
instead of disabling dsi.

If disable dsi without pulling the mipi signal low, the value of
the register will still maintain the setting of the mipi signal being
pulled high.
After resume, even if the mipi signal is not pulled high, it will still
be in the high state.

Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_dsi.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Rex-BC Chen (陳柏辰) April 12, 2022, 7:39 a.m. UTC | #1
On Mon, 2022-04-11 at 10:31 +0800, xinlei.lee@mediatek.com wrote:
> From: Xinlei Lee <xinlei.lee@mediatek.com>
> 
> In the dsi_enable function, mtk_dsi_rxtx_control is to
> pull up the MIPI signal operation. Before dsi_disable,
> MIPI should also be pulled down by writing a register 
> instead of disabling dsi.
> 
> If disable dsi without pulling the mipi signal low, the value of
> the register will still maintain the setting of the mipi signal being
> pulled high.
> After resume, even if the mipi signal is not pulled high, it will
> still
> be in the high state.
> 
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_dsi.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c
> b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index 9ad6f08c8bfe..e35343357f90 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -676,6 +676,8 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
>  	mtk_dsi_reset_engine(dsi);
>  	mtk_dsi_lane0_ulp_mode_enter(dsi);
>  	mtk_dsi_clk_ulp_mode_enter(dsi);
> +	/* set the lane number as 0 to pull down mipi */
> +	writel(0, dsi->regs + DSI_TXRX_CTRL);
>  
>  	mtk_dsi_disable(dsi);
>  

Reviewed-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
CK Hu (胡俊光) April 13, 2022, 9:04 a.m. UTC | #2
Hi, Xinlei:

On Mon, 2022-04-11 at 10:31 +0800, xinlei.lee@mediatek.com wrote:
> From: Xinlei Lee <xinlei.lee@mediatek.com>
> 
> In the dsi_enable function, mtk_dsi_rxtx_control is to
> pull up the MIPI signal operation. Before dsi_disable,
> MIPI should also be pulled down by writing a register 
> instead of disabling dsi.
> 
> If disable dsi without pulling the mipi signal low, the value of
> the register will still maintain the setting of the mipi signal being
> pulled high.
> After resume, even if the mipi signal is not pulled high, it will
> still
> be in the high state.

After add Fixes tag for [1], then

Reviewed-by: CK Hu <ck.hu@mediatek.com>

[1] 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/gpu/drm/mediatek/mtk_dsi.c?h=v5.18-rc2&id=2e54c14e310f655bb0915413e8e4a3da67c78a66

> 
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_dsi.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c
> b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index 9ad6f08c8bfe..e35343357f90 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -676,6 +676,8 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
>  	mtk_dsi_reset_engine(dsi);
>  	mtk_dsi_lane0_ulp_mode_enter(dsi);
>  	mtk_dsi_clk_ulp_mode_enter(dsi);
> +	/* set the lane number as 0 to pull down mipi */
> +	writel(0, dsi->regs + DSI_TXRX_CTRL);
>  
>  	mtk_dsi_disable(dsi);
>
diff mbox series

Patch

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index 9ad6f08c8bfe..e35343357f90 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -676,6 +676,8 @@  static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
 	mtk_dsi_reset_engine(dsi);
 	mtk_dsi_lane0_ulp_mode_enter(dsi);
 	mtk_dsi_clk_ulp_mode_enter(dsi);
+	/* set the lane number as 0 to pull down mipi */
+	writel(0, dsi->regs + DSI_TXRX_CTRL);
 
 	mtk_dsi_disable(dsi);