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

From: Biju Das

Date: Fri Aug 28 2026 - 03:53:26 EST

Hi Tommaso,

Thanks for the feedback

> -----Original Message-----
> From: Tommaso Merciai <tommaso.merciai.xr@xxxxxxxxxxxxxx>
> Sent: 27 August 2026 10:34
> Subject: Re: [PATCH v3 06/13] drm: renesas: rz-du: Add RZ/G3L (R9A08G046) DU support
>
> On Thu, Aug 27, 2026 at 10:12:25AM +0200, Tommaso Merciai wrote:
> > 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

Good catch. Will fix the typo.

Cheers,
Biju

> >
> > rzg2l_du_encoder_mode_valid() is checking the DPAD0 output mode clock
> > then here we should set:
> >
> > .mode_clock_min = 5400,
>
> Apart for that the rest LGTM.
>
> Reviewed-by: Tommaso Merciai <tommaso.merciai.xr@xxxxxxxxxxxxxx>
>
> Kind regards,
> Tommaso
>
> >
> > 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
> > >
> >