diff mbox series

drm/bridge: dw-mipi-dsi: permit configuring the escape clock rate

Message ID 20200904125531.15248-1-narmstrong@baylibre.com (mailing list archive)
State New, archived
Headers show
Series drm/bridge: dw-mipi-dsi: permit configuring the escape clock rate | expand

Commit Message

Neil Armstrong Sept. 4, 2020, 12:55 p.m. UTC
The Amlogic D-PHY in the Amlogic AXG SoC Family does support a frequency
higher than 10MHz for the TX Escape Clock, thus make the target rate
configurable.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 25 +++++++++++++++----
 include/drm/bridge/dw_mipi_dsi.h              |  1 +
 2 files changed, 21 insertions(+), 5 deletions(-)

Comments

Philippe CORNU Sept. 11, 2020, 8:29 a.m. UTC | #1
On 9/4/20 2:55 PM, Neil Armstrong wrote:
> The Amlogic D-PHY in the Amlogic AXG SoC Family does support a frequency
> higher than 10MHz for the TX Escape Clock, thus make the target rate
> configurable.
> 
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> ---
>   drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 25 +++++++++++++++----
>   include/drm/bridge/dw_mipi_dsi.h              |  1 +
>   2 files changed, 21 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> index d580b2aa4ce9..31fc965c66fd 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> @@ -562,15 +562,30 @@ static void dw_mipi_dsi_disable(struct dw_mipi_dsi *dsi)
>   
>   static void dw_mipi_dsi_init(struct dw_mipi_dsi *dsi)
>   {
> +	const struct dw_mipi_dsi_phy_ops *phy_ops = dsi->plat_data->phy_ops;
> +	unsigned int esc_rate; /* in MHz */
> +	u32 esc_clk_division;
> +	int ret;
> +
>   	/*
>   	 * The maximum permitted escape clock is 20MHz and it is derived from
> -	 * lanebyteclk, which is running at "lane_mbps / 8".  Thus we want:
> -	 *
> -	 *     (lane_mbps >> 3) / esc_clk_division < 20
> +	 * lanebyteclk, which is running at "lane_mbps / 8".
> +	 */
> +	if (phy_ops->get_esc_clk_rate) {
> +		ret = phy_ops->get_esc_clk_rate(dsi->plat_data->priv_data,
> +						&esc_rate);
> +		if (ret)
> +			DRM_DEBUG_DRIVER("Phy get_esc_clk_rate() failed\n");
> +	} else
> +		esc_rate = 20; /* Default to 20MHz */
> +
> +	/*
> +	 * We want :
> +	 *     (lane_mbps >> 3) / esc_clk_division < X
>   	 * which is:
> -	 *     (lane_mbps >> 3) / 20 > esc_clk_division
> +	 *     (lane_mbps >> 3) / X > esc_clk_division
>   	 */
> -	u32 esc_clk_division = (dsi->lane_mbps >> 3) / 20 + 1;
> +	esc_clk_division = (dsi->lane_mbps >> 3) / esc_rate + 1;
>   
>   	dsi_write(dsi, DSI_PWR_UP, RESET);
>   
> diff --git a/include/drm/bridge/dw_mipi_dsi.h b/include/drm/bridge/dw_mipi_dsi.h
> index b0e390b3288e..bda8aa7c2280 100644
> --- a/include/drm/bridge/dw_mipi_dsi.h
> +++ b/include/drm/bridge/dw_mipi_dsi.h
> @@ -36,6 +36,7 @@ struct dw_mipi_dsi_phy_ops {
>   			     unsigned int *lane_mbps);
>   	int (*get_timing)(void *priv_data, unsigned int lane_mbps,
>   			  struct dw_mipi_dsi_dphy_timing *timing);
> +	int (*get_esc_clk_rate)(void *priv_data, unsigned int *esc_clk_rate);
>   };
>   
>   struct dw_mipi_dsi_host_ops {
> 

Hi Neil,
Thank you for the patch

Reviewed-by: Philippe Cornu <philippe.cornu@st.com>

Philippe :-)
Neil Armstrong Sept. 11, 2020, 1:02 p.m. UTC | #2
On 11/09/2020 10:29, Philippe CORNU wrote:
> 
> 
> On 9/4/20 2:55 PM, Neil Armstrong wrote:
>> The Amlogic D-PHY in the Amlogic AXG SoC Family does support a frequency
>> higher than 10MHz for the TX Escape Clock, thus make the target rate
>> configurable.
>>
>> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
>> ---
>>   drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 25 +++++++++++++++----
>>   include/drm/bridge/dw_mipi_dsi.h              |  1 +
>>   2 files changed, 21 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
>> index d580b2aa4ce9..31fc965c66fd 100644
>> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
>> @@ -562,15 +562,30 @@ static void dw_mipi_dsi_disable(struct dw_mipi_dsi *dsi)
>>   
>>   static void dw_mipi_dsi_init(struct dw_mipi_dsi *dsi)
>>   {
>> +	const struct dw_mipi_dsi_phy_ops *phy_ops = dsi->plat_data->phy_ops;
>> +	unsigned int esc_rate; /* in MHz */
>> +	u32 esc_clk_division;
>> +	int ret;
>> +
>>   	/*
>>   	 * The maximum permitted escape clock is 20MHz and it is derived from
>> -	 * lanebyteclk, which is running at "lane_mbps / 8".  Thus we want:
>> -	 *
>> -	 *     (lane_mbps >> 3) / esc_clk_division < 20
>> +	 * lanebyteclk, which is running at "lane_mbps / 8".
>> +	 */
>> +	if (phy_ops->get_esc_clk_rate) {
>> +		ret = phy_ops->get_esc_clk_rate(dsi->plat_data->priv_data,
>> +						&esc_rate);
>> +		if (ret)
>> +			DRM_DEBUG_DRIVER("Phy get_esc_clk_rate() failed\n");
>> +	} else
>> +		esc_rate = 20; /* Default to 20MHz */
>> +
>> +	/*
>> +	 * We want :
>> +	 *     (lane_mbps >> 3) / esc_clk_division < X
>>   	 * which is:
>> -	 *     (lane_mbps >> 3) / 20 > esc_clk_division
>> +	 *     (lane_mbps >> 3) / X > esc_clk_division
>>   	 */
>> -	u32 esc_clk_division = (dsi->lane_mbps >> 3) / 20 + 1;
>> +	esc_clk_division = (dsi->lane_mbps >> 3) / esc_rate + 1;
>>   
>>   	dsi_write(dsi, DSI_PWR_UP, RESET);
>>   
>> diff --git a/include/drm/bridge/dw_mipi_dsi.h b/include/drm/bridge/dw_mipi_dsi.h
>> index b0e390b3288e..bda8aa7c2280 100644
>> --- a/include/drm/bridge/dw_mipi_dsi.h
>> +++ b/include/drm/bridge/dw_mipi_dsi.h
>> @@ -36,6 +36,7 @@ struct dw_mipi_dsi_phy_ops {
>>   			     unsigned int *lane_mbps);
>>   	int (*get_timing)(void *priv_data, unsigned int lane_mbps,
>>   			  struct dw_mipi_dsi_dphy_timing *timing);
>> +	int (*get_esc_clk_rate)(void *priv_data, unsigned int *esc_clk_rate);
>>   };
>>   
>>   struct dw_mipi_dsi_host_ops {
>>
> 
> Hi Neil,
> Thank you for the patch
> 
> Reviewed-by: Philippe Cornu <philippe.cornu@st.com>
> 
> Philippe :-)
> 

Thanks !

Applying to drm-misc-next

Neil
diff mbox series

Patch

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
index d580b2aa4ce9..31fc965c66fd 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
@@ -562,15 +562,30 @@  static void dw_mipi_dsi_disable(struct dw_mipi_dsi *dsi)
 
 static void dw_mipi_dsi_init(struct dw_mipi_dsi *dsi)
 {
+	const struct dw_mipi_dsi_phy_ops *phy_ops = dsi->plat_data->phy_ops;
+	unsigned int esc_rate; /* in MHz */
+	u32 esc_clk_division;
+	int ret;
+
 	/*
 	 * The maximum permitted escape clock is 20MHz and it is derived from
-	 * lanebyteclk, which is running at "lane_mbps / 8".  Thus we want:
-	 *
-	 *     (lane_mbps >> 3) / esc_clk_division < 20
+	 * lanebyteclk, which is running at "lane_mbps / 8".
+	 */
+	if (phy_ops->get_esc_clk_rate) {
+		ret = phy_ops->get_esc_clk_rate(dsi->plat_data->priv_data,
+						&esc_rate);
+		if (ret)
+			DRM_DEBUG_DRIVER("Phy get_esc_clk_rate() failed\n");
+	} else
+		esc_rate = 20; /* Default to 20MHz */
+
+	/*
+	 * We want :
+	 *     (lane_mbps >> 3) / esc_clk_division < X
 	 * which is:
-	 *     (lane_mbps >> 3) / 20 > esc_clk_division
+	 *     (lane_mbps >> 3) / X > esc_clk_division
 	 */
-	u32 esc_clk_division = (dsi->lane_mbps >> 3) / 20 + 1;
+	esc_clk_division = (dsi->lane_mbps >> 3) / esc_rate + 1;
 
 	dsi_write(dsi, DSI_PWR_UP, RESET);
 
diff --git a/include/drm/bridge/dw_mipi_dsi.h b/include/drm/bridge/dw_mipi_dsi.h
index b0e390b3288e..bda8aa7c2280 100644
--- a/include/drm/bridge/dw_mipi_dsi.h
+++ b/include/drm/bridge/dw_mipi_dsi.h
@@ -36,6 +36,7 @@  struct dw_mipi_dsi_phy_ops {
 			     unsigned int *lane_mbps);
 	int (*get_timing)(void *priv_data, unsigned int lane_mbps,
 			  struct dw_mipi_dsi_dphy_timing *timing);
+	int (*get_esc_clk_rate)(void *priv_data, unsigned int *esc_clk_rate);
 };
 
 struct dw_mipi_dsi_host_ops {