Re: [PATCH v3 06/13] drm: renesas: rz-du: Add RZ/G3L (R9A08G046) DU support

[Tommaso Merciai]

Hi Biju,
Thanks, for your patch.

On Wed, Aug 26, 2026 at 06:48:40PM +0100, Biju wrote:
> From: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> 
> Add Display Unit support for the Renesas RZ/G3L SoC (R9A08G046). It is
> similar to the one found on RZ/G2L, but has LVDS support.
> 
> Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> ---
> v2->v3:
>  * Set duty cycle handling in DU encoder
>  * Added min/max frequencies for DPI.
> v1->v2:
>  * Dropped the macro RZG2L_DU_FEATURE_SMUX2_DSI_CLK and RZG2L_DU_MAX_LVDS.
>  * Dropped the variable rcdu from struct rzg2l_du_encoder.
>  * Dropped the variable lvds from struct rzg2l_du_device.
> ---
>  drivers/gpu/drm/renesas/rz-du/rzg2l_du_drv.c  | 24 ++++++++++++++++++-
>  drivers/gpu/drm/renesas/rz-du/rzg2l_du_drv.h  |  3 ++-
>  .../gpu/drm/renesas/rz-du/rzg2l_du_encoder.c  | 24 +++++++++++++++++++
>  3 files changed, 49 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/renesas/rz-du/rzg2l_du_drv.c b/drivers/gpu/drm/renesas/rz-du/rzg2l_du_drv.c
> index 3d13f61d3c97..6c2dc86abc7d 100644
> --- a/drivers/gpu/drm/renesas/rz-du/rzg2l_du_drv.c
> +++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_du_drv.c
> @@ -55,6 +55,26 @@ static const struct rzg2l_du_device_info rzg2l_du_r9a07g044_info = {
>  	.mode_clock_max = 83500,
>  };
>  
> +static const struct rzg2l_du_device_info rzg2l_du_r9a08g046_info = {
> +	.channels_mask = BIT(0),
> +	.routes = {
> +		[RZG2L_DU_OUTPUT_DSI0] = {
> +			.possible_outputs = BIT(0),
> +			.port = 0,
> +		},
> +		[RZG2L_DU_OUTPUT_DPAD0] = {
> +			.possible_outputs = BIT(0),
> +			.port = 1,
> +		},
> +		[RZG2L_DU_OUTPUT_LVDS0] = {
> +			.possible_outputs = BIT(0),
> +			.port = 2,
> +		},
> +	},
> +	.mode_clock_min = 5440,
> +	.mode_clock_max = 87000,

Pixel clock must be within the following range:

	– Parallel = 5.4 to 87 MHz

rzg2l_du_encoder_mode_valid() is checking the DPAD0
output mode clock then here we should set:

	.mode_clock_min = 5400,

Thanks, Tommaso


> +};
> +
>  static const struct rzg2l_du_device_info rzg2l_du_r9a09g057_info = {
>  	.channels_mask = BIT(0),
>  	.routes = {
> @@ -81,6 +101,7 @@ static const struct rzg2l_du_device_info rzg2l_du_r9a09g077_info = {
>  static const struct of_device_id rzg2l_du_of_table[] = {
>  	{ .compatible = "renesas,r9a07g043u-du", .data = &rzg2l_du_r9a07g043u_info },
>  	{ .compatible = "renesas,r9a07g044-du", .data = &rzg2l_du_r9a07g044_info },
> +	{ .compatible = "renesas,r9a08g046-du", .data = &rzg2l_du_r9a08g046_info },
>  	{ .compatible = "renesas,r9a09g057-du", .data = &rzg2l_du_r9a09g057_info },
>  	{ .compatible = "renesas,r9a09g077-du", .data = &rzg2l_du_r9a09g077_info },
>  	{ /* sentinel */ }
> @@ -92,7 +113,8 @@ const char *rzg2l_du_output_name(enum rzg2l_du_output output)
>  {
>  	static const char * const names[] = {
>  		[RZG2L_DU_OUTPUT_DSI0] = "DSI0",
> -		[RZG2L_DU_OUTPUT_DPAD0] = "DPAD0"
> +		[RZG2L_DU_OUTPUT_DPAD0] = "DPAD0",
> +		[RZG2L_DU_OUTPUT_LVDS0] = "LVDS0"
>  	};
>  
>  	if (output >= ARRAY_SIZE(names))
> diff --git a/drivers/gpu/drm/renesas/rz-du/rzg2l_du_drv.h b/drivers/gpu/drm/renesas/rz-du/rzg2l_du_drv.h
> index baf076d69cda..e9626ef37cde 100644
> --- a/drivers/gpu/drm/renesas/rz-du/rzg2l_du_drv.h
> +++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_du_drv.h
> @@ -25,6 +25,7 @@ struct drm_property;
>  enum rzg2l_du_output {
>  	RZG2L_DU_OUTPUT_DSI0,
>  	RZG2L_DU_OUTPUT_DPAD0,
> +	RZG2L_DU_OUTPUT_LVDS0,
>  	RZG2L_DU_OUTPUT_MAX,
>  };
>  
> @@ -33,7 +34,7 @@ enum rzg2l_du_output {
>   * @possible_outputs: bitmask of possible outputs
>   * @port: device tree port number corresponding to this output route
>   *
> - * The DU has 2 possible outputs (DPAD0, DSI0). Output routing data
> + * The DU has 3 possible outputs (DPAD0, DSI0, LVDS0). Output routing data
>   * specify the valid SoC outputs, which CRTC can drive the output, and the type
>   * of in-SoC encoder for the output.
>   */
> diff --git a/drivers/gpu/drm/renesas/rz-du/rzg2l_du_encoder.c b/drivers/gpu/drm/renesas/rz-du/rzg2l_du_encoder.c
> index 3d0999e4fcfd..a1b48973aa8e 100644
> --- a/drivers/gpu/drm/renesas/rz-du/rzg2l_du_encoder.c
> +++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_du_encoder.c
> @@ -7,6 +7,7 @@
>   * Based on rcar_du_encoder.c
>   */
>  
> +#include <linux/clk.h>
>  #include <linux/export.h>
>  #include <linux/of.h>
>  
> @@ -15,6 +16,7 @@
>  #include <drm/drm_bridge_connector.h>
>  #include <drm/drm_panel.h>
>  
> +#include "rzg2l_du_crtc.h"
>  #include "rzg2l_du_drv.h"
>  #include "rzg2l_du_encoder.h"
>  
> @@ -64,8 +66,30 @@ rzg2l_du_encoder_mode_valid(struct drm_encoder *encoder,
>  	return MODE_OK;
>  }
>  
> +static void rzg2l_du_encoder_atomic_mode_set(struct drm_encoder *encoder,
> +					     struct drm_crtc_state *crtc_state,
> +					     struct drm_connector_state *conn_state)
> +{
> +	struct rzg2l_du_encoder *renc = to_rzg2l_encoder(encoder);
> +	struct rzg2l_du_crtc *rcrtc = to_rzg2l_crtc(crtc_state->crtc);
> +	struct clk *clk_parent;
> +
> +	clk_parent = clk_get_parent(rcrtc->rzg2l_clocks.dclk);
> +
> +	/*
> +	 * Request appropriate duty cycle
> +	 * - LVDS path has DUTY H/L=4/3, 4/7 duty cycle.
> +	 * - DSI/RGB path has symmetric 50% duty cycle.
> +	 */
> +	if (renc->output == RZG2L_DU_OUTPUT_LVDS0)
> +		clk_set_duty_cycle(clk_parent, 4, 7);
> +	else
> +		clk_set_duty_cycle(clk_parent, 1, 2);
> +}
> +
>  static const struct drm_encoder_helper_funcs rzg2l_du_encoder_helper_funcs = {
>  	.mode_valid = rzg2l_du_encoder_mode_valid,
> +	.atomic_mode_set = rzg2l_du_encoder_atomic_mode_set,
>  };
>  
>  int rzg2l_du_encoder_init(struct rzg2l_du_device  *rcdu,
> -- 
> 2.43.0
>