[PATCH] drm/bridge: nwl-dsi: implement MIPI_DSI_MODE_NO_EOT_PACKET

[PATCH] drm/bridge: nwl-dsi: implement MIPI_DSI_MODE_NO_EOT_PACKET

[Kevin Groeneveld]

Previously EOT packets were only being enabled when
MIPI_DSI_CLOCK_NON_CONTINUOUS was set in the dsi_mode_flags. However this
really should be based on MIPI_DSI_MODE_NO_EOT_PACKET instead.

Some displays require EOT packets and a continuous clock which was an
impossible combination to achieve with the current driver.

Signed-off-by: Kevin Groeneveld <kgroeneveld@lenbrook.com>
---
 drivers/gpu/drm/bridge/nwl-dsi.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/bridge/nwl-dsi.c b/drivers/gpu/drm/bridge/nwl-dsi.c
index 6dc2a4e191d7..bb8404ffd3f5 100644
--- a/drivers/gpu/drm/bridge/nwl-dsi.c
+++ b/drivers/gpu/drm/bridge/nwl-dsi.c
@@ -211,7 +211,7 @@ static u32 us2lp(u32 lp_clk_rate, unsigned long us)
 
 static int nwl_dsi_config_host(struct nwl_dsi *dsi)
 {
-	u32 cycles;
+	u32 val, cycles;
 	struct phy_configure_opts_mipi_dphy *cfg = &dsi->phy_cfg.mipi_dphy;
 
 	if (dsi->lanes < 1 || dsi->lanes > 4)
@@ -220,13 +220,8 @@ static int nwl_dsi_config_host(struct nwl_dsi *dsi)
 	DRM_DEV_DEBUG_DRIVER(dsi->dev, "DSI Lanes %d\n", dsi->lanes);
 	nwl_dsi_write(dsi, NWL_DSI_CFG_NUM_LANES, dsi->lanes - 1);
 
-	if (dsi->dsi_mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS) {
-		nwl_dsi_write(dsi, NWL_DSI_CFG_NONCONTINUOUS_CLK, 0x01);
-		nwl_dsi_write(dsi, NWL_DSI_CFG_AUTOINSERT_EOTP, 0x01);
-	} else {
-		nwl_dsi_write(dsi, NWL_DSI_CFG_NONCONTINUOUS_CLK, 0x00);
-		nwl_dsi_write(dsi, NWL_DSI_CFG_AUTOINSERT_EOTP, 0x00);
-	}
+	val = (dsi->dsi_mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS) ? 0x01 : 0x00;
+	nwl_dsi_write(dsi, NWL_DSI_CFG_NONCONTINUOUS_CLK, val);
 
 	/* values in byte clock cycles */
 	cycles = ui2bc(cfg->clk_pre);
@@ -241,6 +236,8 @@ static int nwl_dsi_config_host(struct nwl_dsi *dsi)
 	DRM_DEV_DEBUG_DRIVER(dsi->dev, "cfg_tx_gap: 0x%x\n", cycles);
 	nwl_dsi_write(dsi, NWL_DSI_CFG_TX_GAP, cycles);
 
+	val = (dsi->dsi_mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET) ? 0x00 : 0x01;
+	nwl_dsi_write(dsi, NWL_DSI_CFG_AUTOINSERT_EOTP, val);
 	nwl_dsi_write(dsi, NWL_DSI_CFG_EXTRA_CMDS_AFTER_EOTP, 0x01);
 	nwl_dsi_write(dsi, NWL_DSI_CFG_HTX_TO_COUNT, 0x00);
 	nwl_dsi_write(dsi, NWL_DSI_CFG_LRX_H_TO_COUNT, 0x00);
-- 
2.34.1

Re: [PATCH] drm/bridge: nwl-dsi: implement MIPI_DSI_MODE_NO_EOT_PACKET

[Neil Armstrong]

Hi,

On 18/03/2023 23:33, Kevin Groeneveld wrote:
> Previously EOT packets were only being enabled when
> MIPI_DSI_CLOCK_NON_CONTINUOUS was set in the dsi_mode_flags. However this
> really should be based on MIPI_DSI_MODE_NO_EOT_PACKET instead.
> 
> Some displays require EOT packets and a continuous clock which was an
> impossible combination to achieve with the current driver.
> 
> Signed-off-by: Kevin Groeneveld <kgroeneveld@lenbrook.com>


Thanks for the patch, can you provide a Fixes tag ?

Neil

> ---
>   drivers/gpu/drm/bridge/nwl-dsi.c | 13 +++++--------
>   1 file changed, 5 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/nwl-dsi.c b/drivers/gpu/drm/bridge/nwl-dsi.c
> index 6dc2a4e191d7..bb8404ffd3f5 100644
> --- a/drivers/gpu/drm/bridge/nwl-dsi.c
> +++ b/drivers/gpu/drm/bridge/nwl-dsi.c
> @@ -211,7 +211,7 @@ static u32 us2lp(u32 lp_clk_rate, unsigned long us)
>   
>   static int nwl_dsi_config_host(struct nwl_dsi *dsi)
>   {
> -	u32 cycles;
> +	u32 val, cycles;
>   	struct phy_configure_opts_mipi_dphy *cfg = &dsi->phy_cfg.mipi_dphy;
>   
>   	if (dsi->lanes < 1 || dsi->lanes > 4)
> @@ -220,13 +220,8 @@ static int nwl_dsi_config_host(struct nwl_dsi *dsi)
>   	DRM_DEV_DEBUG_DRIVER(dsi->dev, "DSI Lanes %d\n", dsi->lanes);
>   	nwl_dsi_write(dsi, NWL_DSI_CFG_NUM_LANES, dsi->lanes - 1);
>   
> -	if (dsi->dsi_mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS) {
> -		nwl_dsi_write(dsi, NWL_DSI_CFG_NONCONTINUOUS_CLK, 0x01);
> -		nwl_dsi_write(dsi, NWL_DSI_CFG_AUTOINSERT_EOTP, 0x01);
> -	} else {
> -		nwl_dsi_write(dsi, NWL_DSI_CFG_NONCONTINUOUS_CLK, 0x00);
> -		nwl_dsi_write(dsi, NWL_DSI_CFG_AUTOINSERT_EOTP, 0x00);
> -	}
> +	val = (dsi->dsi_mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS) ? 0x01 : 0x00;
> +	nwl_dsi_write(dsi, NWL_DSI_CFG_NONCONTINUOUS_CLK, val);
>   
>   	/* values in byte clock cycles */
>   	cycles = ui2bc(cfg->clk_pre);
> @@ -241,6 +236,8 @@ static int nwl_dsi_config_host(struct nwl_dsi *dsi)
>   	DRM_DEV_DEBUG_DRIVER(dsi->dev, "cfg_tx_gap: 0x%x\n", cycles);
>   	nwl_dsi_write(dsi, NWL_DSI_CFG_TX_GAP, cycles);
>   
> +	val = (dsi->dsi_mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET) ? 0x00 : 0x01;
> +	nwl_dsi_write(dsi, NWL_DSI_CFG_AUTOINSERT_EOTP, val);
>   	nwl_dsi_write(dsi, NWL_DSI_CFG_EXTRA_CMDS_AFTER_EOTP, 0x01);
>   	nwl_dsi_write(dsi, NWL_DSI_CFG_HTX_TO_COUNT, 0x00);
>   	nwl_dsi_write(dsi, NWL_DSI_CFG_LRX_H_TO_COUNT, 0x00);

Re: [PATCH] drm/bridge: nwl-dsi: implement MIPI_DSI_MODE_NO_EOT_PACKET

[Kevin Groeneveld]

Hi Neil,

On 2023-03-20 06:43, Neil Armstrong wrote:
> Thanks for the patch, can you provide a Fixes tag ?
> 
> Neil

I never seem to think about a fixes tag unless it was a regression. This 
limitation has existed since the first commit for this driver. If there 
should be a fixes tag then I guess it would be:

Fixes: 44cfc6233447 ("drm/bridge: Add NWL MIPI DSI host controller support")

Kevin