Hi Tommaso,

Thank you for the patch.


On Mon, Feb 2, 2026 at 12:04 PM Tommaso Merciai
<[email protected]> wrote:
>
> The RZ/G3E Soc has 2 LCD controller (LCDC), contain a Frame Compression
> Processor (FCPVD), a Video Signal Processor (VSPD), Video Signal
> Processor (VSPD), and Display Unit (DU).
>
> LCDC0 supports DSI and LVDS (single or dual-channel) outputs.
> LCDC1 supports DSI, LVDS (single-channel), and RGB outputs.
>
> Depending on the selected output, the correct SMUX2 clock parent must be
> chosen based on the requested duty cycle:
>
>  - Index 0 for LVDS -> CDIV7_DSIx_CLK (DUTY H/L=4/3, 4/7 duty cycle)
>  - Index 1 for DSI/DPAD -> CSDIV_2to16_PLLDSIx (symmetric 50% duty cycle)
>
> To support this behavior, introduce the `RG2L_DU_FEATURE_SMUX2_DSI_CLK`
> feature flag and extend the `rzg2l_du_device_info` structure to include a
> features field. Also, add a new helper function `rzg2l_du_has()` to check
> for feature flags.
>
> Add support for the RZ/G3E SoC by introducing:
>  - `rzg2l_du_r9a09g047_du_info` structure
>  - The `renesas,r9a09g047-du` compatible string
>
> Additionally, introduce the missing output definitions
> `RZG2L_DU_OUTPUT_LVDS{0,1}`.
>
> Introduce `rzg2l_du_crtc_atomic_check()` helper to store the routes from
> the CRTC output to the DU outputs.
>
> Signed-off-by: Tommaso Merciai <[email protected]>
> ---
> v1->v2:
>  - Instead of using clk-provider API to select the right parent clock,
>    based on the outputs. Just set the correct duty cycle based on the
>    output, this reflects at CPG lvl to select the right parent.
>  - Updated commit message accordingly.
>
> v2->v3:
>  - No changes.
>
> v3->v4:
>  - No changes.
>
>  drivers/gpu/drm/renesas/rz-du/rzg2l_du_crtc.c | 48 +++++++++++++++++++
>  drivers/gpu/drm/renesas/rz-du/rzg2l_du_drv.c  | 26 ++++++++++
>  drivers/gpu/drm/renesas/rz-du/rzg2l_du_drv.h  | 11 +++++
>  3 files changed, 85 insertions(+)
>
> diff --git a/drivers/gpu/drm/renesas/rz-du/rzg2l_du_crtc.c 
> b/drivers/gpu/drm/renesas/rz-du/rzg2l_du_crtc.c
> index 6e7aac6219be..c51ba4b8c383 100644
> --- a/drivers/gpu/drm/renesas/rz-du/rzg2l_du_crtc.c
> +++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_du_crtc.c
> @@ -64,11 +64,32 @@
>  static void rzg2l_du_crtc_set_display_timing(struct rzg2l_du_crtc *rcrtc)
>  {
>         const struct drm_display_mode *mode = 
> &rcrtc->crtc.state->adjusted_mode;
> +       struct rzg2l_du_crtc_state *rstate =
> +               to_rzg2l_crtc_state(rcrtc->crtc.state);
>         unsigned long mode_clock = mode->clock * 1000;
>         u32 ditr0, ditr1, ditr2, ditr3, ditr4, pbcr0;
>         struct rzg2l_du_device *rcdu = rcrtc->dev;
>
>         clk_prepare_enable(rcrtc->rzg2l_clocks.dclk);
> +
> +       if (rzg2l_du_has(rcdu, RG2L_DU_FEATURE_SMUX2_DSI_CLK)) {
> +               struct clk *clk_parent;
> +
> +               clk_parent = clk_get_parent(rcrtc->rzg2l_clocks.dclk);
> +
> +               /*
> +                * Request appropriate duty cycle to let clock driver select
> +                * the correct parent:
> +                * - CDIV7_DSIx_CLK (LVDS path) has DUTY H/L=4/3, 4/7 duty 
> cycle.
> +                * - CSDIV_2to16_PLLDSIx (DSI/RGB path) has symmetric 50% 
> duty cycle.
> +                */
> +               if (rstate->outputs == BIT(RZG2L_DU_OUTPUT_LVDS0) ||
> +                   rstate->outputs == BIT(RZG2L_DU_OUTPUT_LVDS1))
> +                       clk_set_duty_cycle(clk_parent, 4, 7);
> +               else
> +                       clk_set_duty_cycle(clk_parent, 1, 2);
> +       }
> +
>         clk_set_rate(rcrtc->rzg2l_clocks.dclk, mode_clock);
>
>         ditr0 = (DU_DITR0_DEMD_HIGH
> @@ -248,6 +269,32 @@ static void rzg2l_du_crtc_stop(struct rzg2l_du_crtc 
> *rcrtc)
>   * CRTC Functions
>   */
>
> +static int rzg2l_du_crtc_atomic_check(struct drm_crtc *crtc,
> +                                     struct drm_atomic_state *state)
> +{
> +       struct drm_crtc_state *crtc_state = 
> drm_atomic_get_new_crtc_state(state,
> +                                                                         
> crtc);
> +       struct rzg2l_du_crtc_state *rstate = to_rzg2l_crtc_state(crtc_state);
> +       struct drm_encoder *encoder;
> +
> +       /* Store the routes from the CRTC output to the DU outputs. */
> +       rstate->outputs = 0;
> +
> +       drm_for_each_encoder_mask(encoder, crtc->dev,
> +                                 crtc_state->encoder_mask) {
> +               struct rzg2l_du_encoder *renc;
> +
> +               /* Skip the writeback encoder. */
> +               if (encoder->encoder_type == DRM_MODE_ENCODER_VIRTUAL)
> +                       continue;
> +
> +               renc = to_rzg2l_encoder(encoder);
> +               rstate->outputs |= BIT(renc->output);
> +       }
> +
> +       return 0;
> +}
> +
>  static void rzg2l_du_crtc_atomic_enable(struct drm_crtc *crtc,
>                                         struct drm_atomic_state *state)
>  {
> @@ -296,6 +343,7 @@ static void rzg2l_du_crtc_atomic_flush(struct drm_crtc 
> *crtc,
>  }
>
>  static const struct drm_crtc_helper_funcs crtc_helper_funcs = {
> +       .atomic_check = rzg2l_du_crtc_atomic_check,
This change and adding rzg2l_du_crtc_atomic_check() can be a separate
patch as the same changes are required for T2H and its not specific to
G3E.

>         .atomic_flush = rzg2l_du_crtc_atomic_flush,
>         .atomic_enable = rzg2l_du_crtc_atomic_enable,
>         .atomic_disable = rzg2l_du_crtc_atomic_disable,
> 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 0fef33a5a089..84e6bf186f5d 100644
> --- a/drivers/gpu/drm/renesas/rz-du/rzg2l_du_drv.c
> +++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_du_drv.c
> @@ -51,6 +51,29 @@ static const struct rzg2l_du_device_info 
> rzg2l_du_r9a07g044_info = {
>         }
>  };
>
> +static const struct rzg2l_du_device_info rzg2l_du_r9a09g047_du_info = {
> +       .features = RG2L_DU_FEATURE_SMUX2_DSI_CLK,
> +       .channels_mask = BIT(0),
> +       .routes = {
> +               [RZG2L_DU_OUTPUT_DSI0] = {
> +                       .possible_outputs = BIT(0),
> +                       .port = 0,
> +               },
> +               [RZG2L_DU_OUTPUT_LVDS0] = {
> +                       .possible_outputs = BIT(0),
> +                       .port = 1,
> +               },
> +               [RZG2L_DU_OUTPUT_LVDS1] = {
> +                       .possible_outputs = BIT(0),
> +                       .port = 2,
> +               },
> +               [RZG2L_DU_OUTPUT_DPAD0] = {
> +                       .possible_outputs = BIT(0),
> +                       .port = 3,
> +               },
> +       },
> +};
> +
>  static const struct rzg2l_du_device_info rzg2l_du_r9a09g057_info = {
>         .channels_mask = BIT(0),
>         .routes = {
> @@ -64,6 +87,7 @@ static const struct rzg2l_du_device_info 
> rzg2l_du_r9a09g057_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,r9a09g047-du", .data = 
> &rzg2l_du_r9a09g047_du_info },
>         { .compatible = "renesas,r9a09g057-du", .data = 
> &rzg2l_du_r9a09g057_info },
>         { /* sentinel */ }
>  };
> @@ -74,6 +98,8 @@ const char *rzg2l_du_output_name(enum rzg2l_du_output 
> output)
>  {
>         static const char * const names[] = {
>                 [RZG2L_DU_OUTPUT_DSI0] = "DSI0",
> +               [RZG2L_DU_OUTPUT_LVDS0] = "LVDS0",
> +               [RZG2L_DU_OUTPUT_LVDS1] = "LVDS1",
>                 [RZG2L_DU_OUTPUT_DPAD0] = "DPAD0"
>         };
>
> 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 58806c2a8f2b..c6f9dc46ab31 100644
> --- a/drivers/gpu/drm/renesas/rz-du/rzg2l_du_drv.h
> +++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_du_drv.h
> @@ -20,8 +20,12 @@
>  struct device;
>  struct drm_property;
>
> +#define RG2L_DU_FEATURE_SMUX2_DSI_CLK  BIT(0)  /* Per output mux */
> +
>  enum rzg2l_du_output {
>         RZG2L_DU_OUTPUT_DSI0,
> +       RZG2L_DU_OUTPUT_LVDS0,
> +       RZG2L_DU_OUTPUT_LVDS1,
>         RZG2L_DU_OUTPUT_DPAD0,
>         RZG2L_DU_OUTPUT_MAX,
>  };
> @@ -46,6 +50,7 @@ struct rzg2l_du_output_routing {
>   * @routes: array of CRTC to output routes, indexed by output 
> (RZG2L_DU_OUTPUT_*)
>   */
>  struct rzg2l_du_device_info {
> +       unsigned int features;
The member description needs adding.

Cheers,
Prabhakar

>         unsigned int channels_mask;
>         struct rzg2l_du_output_routing routes[RZG2L_DU_OUTPUT_MAX];
>  };
> @@ -73,6 +78,12 @@ static inline struct rzg2l_du_device 
> *to_rzg2l_du_device(struct drm_device *dev)
>         return container_of(dev, struct rzg2l_du_device, ddev);
>  }
>
> +static inline bool rzg2l_du_has(struct rzg2l_du_device *rcdu,
> +                               unsigned int feature)
> +{
> +       return rcdu->info->features & feature;
> +}
> +
>  const char *rzg2l_du_output_name(enum rzg2l_du_output output);
>
>  #endif /* __RZG2L_DU_DRV_H__ */
> --
> 2.43.0
>
>

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