Hi Biju,
Thanks for your patch.

On Sun, May 24, 2026 at 08:44:51PM +0100, Biju wrote:
> From: Biju Das <[email protected]>
> 
> Add support for the RZ/G3L LVDS encoder driver. It operates in single-link
> mode with 4 lanes (Data) + 1 lane (Clock) and supports pixel clock rates
> from 25 to 87 MHz. The LVDS module cannot be used at the same time as
> MIPI-DSI. However, LVDS and the DSI interface share a peripheral clock and
> the MIPI_DSI_PRESET_N reset signal. Also, the MIPI_DSI_CMN_RSTB and
> MIPI_DSI_ARESET_N reset signals must be asserted before using the LVDS
> module.
> 

I thinks this should be v3 instead of v2.
Apart from that patch LGTM.

Tested on RZ/G3E LVDS ch0.

Tested-by: Tommaso Merciai <[email protected]>
Reviewed-by: Tommaso Merciai <[email protected]>

Kind Regards,
Tommaso

> Signed-off-by: Tommaso Merciai <[email protected]>
> Signed-off-by: Biju Das <[email protected]>
> ---
> v2->v3:
>  * Replace drm_atomic_state with drm_atomic_commit in
>    rzg3l_lvds_atomic_{en,dis}able().
>  * Drop local variable ret and dev_err() messages in
>    rzg3l_lvds_atomic_enable(); use WARN_ON() instead to
>    capture unexpected failures since atomic_enable should not fail.
>  * Drop local variable next_bridge from rzg3l_lvds_probe().
> v1->v2:
>  * Dropped unused function rzg3l_lvds_is_connected() and removed the 
>    corresponding header file rzg3l_lvds.h
>  * Dropped next_bridge from struct rzg3l_lvds instead using bridge's
>    next_bridge.
>  * Replaced pm_runtime_resume_and_get()->pm_runtime_get_sync() as
>    atomic_enable doesn't fail and for each enable there always will be an
>    atomic_disable() call.
>  * Started using DEFINE_RUNTIME_DEV_PM_OPS for PM callback.
>  * Replaced rzg3l_lvds_parse_dt() with devm_drm_of_get_bridge() in probe()
>  * Started using reset_control_bulk_*() in rzg3l_lvds_pm_runtime_{suspend,
>    resume}()
> ---
>  drivers/gpu/drm/renesas/rz-du/Kconfig         |  13 +
>  drivers/gpu/drm/renesas/rz-du/Makefile        |   1 +
>  drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c    | 277 ++++++++++++++++++
>  .../gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h   |  26 ++
>  4 files changed, 317 insertions(+)
>  create mode 100644 drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c
>  create mode 100644 drivers/gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h
> 
> diff --git a/drivers/gpu/drm/renesas/rz-du/Kconfig 
> b/drivers/gpu/drm/renesas/rz-du/Kconfig
> index 7f2ef7137ae5..cbfc7b6bccb8 100644
> --- a/drivers/gpu/drm/renesas/rz-du/Kconfig
> +++ b/drivers/gpu/drm/renesas/rz-du/Kconfig
> @@ -26,3 +26,16 @@ config DRM_RZG2L_MIPI_DSI
>       def_tristate DRM_RZG2L_DU
>       depends on DRM_RZG2L_USE_MIPI_DSI
>       select DRM_MIPI_DSI
> +
> +config DRM_RZG3L_USE_LVDS
> +     bool "RZ/G3L DU LVDS Encoder Support"
> +     depends on DRM_BRIDGE && OF
> +     default DRM_RZG2L_DU
> +     help
> +       Enable support for the RZ/G3L Display Unit embedded LVDS encoders.
> +
> +config DRM_RZG3L_LVDS
> +     def_tristate DRM_RZG2L_DU
> +     depends on DRM_RZG3L_USE_LVDS
> +     select DRM_KMS_HELPER
> +     select DRM_PANEL
> diff --git a/drivers/gpu/drm/renesas/rz-du/Makefile 
> b/drivers/gpu/drm/renesas/rz-du/Makefile
> index 2987900ea6b6..46decb7ac4f1 100644
> --- a/drivers/gpu/drm/renesas/rz-du/Makefile
> +++ b/drivers/gpu/drm/renesas/rz-du/Makefile
> @@ -8,3 +8,4 @@ rzg2l-du-drm-$(CONFIG_VIDEO_RENESAS_VSP1)     += 
> rzg2l_du_vsp.o
>  obj-$(CONFIG_DRM_RZG2L_DU)           += rzg2l-du-drm.o
>  
>  obj-$(CONFIG_DRM_RZG2L_MIPI_DSI)     += rzg2l_mipi_dsi.o
> +obj-$(CONFIG_DRM_RZG3L_LVDS)         += rzg3l_lvds.o
> diff --git a/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c 
> b/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c
> new file mode 100644
> index 000000000000..a51c3e5a2efe
> --- /dev/null
> +++ b/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c
> @@ -0,0 +1,277 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * RZ/G3L LVDS Encoder Driver
> + *
> + * Copyright (C) 2026 Renesas Electronics Corporation
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/media-bus-format.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/of_graph.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
> +#include <linux/reset.h>
> +
> +#include <drm/drm_atomic.h>
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_bridge.h>
> +#include <drm/drm_of.h>
> +#include <drm/drm_panel.h>
> +#include <drm/drm_probe_helper.h>
> +
> +#include "rzg3l_lvds_regs.h"
> +
> +enum rzg3l_lvds_mode {
> +     RZG3L_LVDS_MODE_JEIDA = 0,
> +     RZG3L_LVDS_MODE_JEIDA_MIRROR = 1,
> +     RZG3L_LVDS_MODE_MODE2 = 2,
> +     RZG3L_LVDS_MODE_MODE2_MIRROR = 3,
> +     RZG3L_LVDS_MODE_VESA = 4,
> +     RZG3L_LVDS_MODE_VESA_MIRROR = 5,
> +     RZG3L_LVDS_MODE_MODE6 = 6,
> +     RZG3L_LVDS_MODE_MODE6_MIRROR = 7,
> +};
> +
> +struct rzg3l_lvds {
> +     struct device *dev;
> +     struct reset_control *prstc;
> +     struct reset_control *lvd_rstc;
> +     struct regmap *regmap;
> +     struct drm_bridge bridge;
> +};
> +
> +#define bridge_to_rzg3l_lvds(b) \
> +     container_of(b, struct rzg3l_lvds, bridge)
> +
> +/* 
> -----------------------------------------------------------------------------
> + * Bridge
> + */
> +
> +static void rzg3l_lvds_atomic_enable(struct drm_bridge *bridge,
> +                                  struct drm_atomic_commit *state)
> +{
> +     struct rzg3l_lvds *lvds = bridge_to_rzg3l_lvds(bridge);
> +     const struct drm_bridge_state *bridge_state;
> +     u32 fmt;
> +
> +     /* Get the LVDS format from the bridge state. */
> +     bridge_state = drm_atomic_get_new_bridge_state(state, bridge);
> +     if (WARN_ON(!bridge_state))
> +             return;
> +
> +     switch (bridge_state->output_bus_cfg.format) {
> +     case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
> +             fmt = RZG3L_LVDS_MODE_JEIDA;
> +             break;
> +     case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
> +             fmt = RZG3L_LVDS_MODE_VESA;
> +             break;
> +     default:
> +             fmt = RZG3L_LVDS_MODE_VESA;
> +             dev_warn(lvds->dev, "Unsupported bus fmt 0x%04x\n",
> +                      bridge_state->output_bus_cfg.format);
> +             break;
> +     }
> +
> +     if (WARN_ON(pm_runtime_get_sync(lvds->dev) < 0))
> +             return;
> +
> +     regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
> +                        LVDS_0_PHY_CH_EN_BGR, LVDS_0_PHY_CH_EN_BGR);
> +     fsleep(20);
> +
> +     regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
> +                        LVDS_0_PHY_CH_EN_LDO, LVDS_0_PHY_CH_EN_LDO);
> +     fsleep(10);
> +
> +     regmap_write(lvds->regmap, LVDS_CMN, LVDS_CMN_RST_PHY0_SEL);
> +     regmap_update_bits(lvds->regmap, LVDS_0_CTL_OFFSET,
> +                        LVDS_0_CTL_FMT_SEL_MSK,
> +                        FIELD_PREP(LVDS_0_CTL_FMT_SEL_MSK, fmt));
> +     regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
> +                        LVDS_0_PHY_CH_IO_EN_MSK, LVDS_0_PHY_CH_IO_EN);
> +     regmap_write(lvds->regmap, LVDS_CMN,
> +                  LVDS_CMN_RST_PHY0_SEL | LVDS_CMN_PHY_RESET);
> +     fsleep(100);
> +}
> +
> +static void rzg3l_lvds_atomic_disable(struct drm_bridge *bridge,
> +                                   struct drm_atomic_commit *state)
> +{
> +     struct rzg3l_lvds *lvds = bridge_to_rzg3l_lvds(bridge);
> +
> +     regmap_update_bits(lvds->regmap, LVDS_CMN, LVDS_CMN_PHY_RESET, 0);
> +     regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
> +                        LVDS_0_PHY_CH_IO_EN_MSK, 0);
> +     regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
> +                        LVDS_0_PHY_CH_EN_LDO, 0);
> +     regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
> +                        LVDS_0_PHY_CH_EN_BGR, 0);
> +
> +     pm_runtime_put(lvds->dev);
> +}
> +
> +static int rzg3l_lvds_attach(struct drm_bridge *bridge,
> +                          struct drm_encoder *encoder,
> +                          enum drm_bridge_attach_flags flags)
> +{
> +     struct rzg3l_lvds *lvds = bridge_to_rzg3l_lvds(bridge);
> +
> +     if (!lvds->bridge.next_bridge)
> +             return 0;
> +
> +     return drm_bridge_attach(encoder, lvds->bridge.next_bridge, bridge, 
> flags);
> +}
> +
> +static enum drm_mode_status
> +rzg3l_lvds_bridge_mode_valid(struct drm_bridge *bridge,
> +                          const struct drm_display_info *info,
> +                          const struct drm_display_mode *mode)
> +{
> +     if (mode->clock > 87000)
> +             return MODE_CLOCK_HIGH;
> +
> +     if (mode->clock < 25000)
> +             return MODE_CLOCK_LOW;
> +
> +     return MODE_OK;
> +}
> +
> +static const struct drm_bridge_funcs rzg3l_lvds_bridge_ops = {
> +     .attach = rzg3l_lvds_attach,
> +     .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
> +     .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
> +     .atomic_reset = drm_atomic_helper_bridge_reset,
> +     .atomic_enable = rzg3l_lvds_atomic_enable,
> +     .atomic_disable = rzg3l_lvds_atomic_disable,
> +     .mode_valid = rzg3l_lvds_bridge_mode_valid,
> +};
> +
> +/* 
> -----------------------------------------------------------------------------
> + * Power Management
> + */
> +
> +static int rzg3l_lvds_pm_runtime_suspend(struct device *dev)
> +{
> +     struct rzg3l_lvds *lvds = dev_get_drvdata(dev);
> +     struct reset_control_bulk_data resets[] = {
> +             { .rstc = lvds->lvd_rstc },
> +             { .rstc = lvds->prstc },
> +     };
> +
> +     return reset_control_bulk_assert(ARRAY_SIZE(resets), resets);
> +}
> +
> +static int rzg3l_lvds_pm_runtime_resume(struct device *dev)
> +{
> +     struct rzg3l_lvds *lvds = dev_get_drvdata(dev);
> +     struct reset_control_bulk_data resets[] = {
> +             { .rstc = lvds->lvd_rstc },
> +             { .rstc = lvds->prstc },
> +     };
> +
> +     return reset_control_bulk_deassert(ARRAY_SIZE(resets), resets);
> +}
> +
> +static DEFINE_RUNTIME_DEV_PM_OPS(rzg3l_lvds_pm_ops,
> +                              rzg3l_lvds_pm_runtime_suspend,
> +                              rzg3l_lvds_pm_runtime_resume, NULL);
> +
> +/* 
> -----------------------------------------------------------------------------
> + * Probe & Remove
> + */
> +
> +static int rzg3l_lvds_probe(struct platform_device *pdev)
> +{
> +     struct reset_control *rstc, *arstc;
> +     struct device *dev = &pdev->dev;
> +     struct rzg3l_lvds *lvds;
> +     int ret;
> +
> +     lvds = devm_drm_bridge_alloc(dev, struct rzg3l_lvds, bridge,
> +                                  &rzg3l_lvds_bridge_ops);
> +     if (IS_ERR(lvds))
> +             return PTR_ERR(lvds);
> +
> +     lvds->dev = dev;
> +     lvds->bridge.of_node = pdev->dev.of_node;
> +
> +     lvds->regmap = syscon_node_to_regmap(dev->of_node->parent);
> +     if (IS_ERR(lvds->regmap))
> +             return PTR_ERR(lvds->regmap);
> +
> +     rstc = devm_reset_control_get_optional_exclusive(dev, "rst");
> +     if (IS_ERR(rstc))
> +             return dev_err_probe(dev, PTR_ERR(rstc), "failed to get rst\n");
> +
> +     arstc = devm_reset_control_get_optional_exclusive(dev, "arst");
> +     if (IS_ERR(arstc))
> +             return dev_err_probe(dev, PTR_ERR(arstc),
> +                                  "failed to get arst\n");
> +
> +     lvds->prstc = devm_reset_control_get_shared(dev, "prst");
> +     if (IS_ERR(lvds->prstc))
> +             return dev_err_probe(dev, PTR_ERR(lvds->prstc),
> +                                  "failed to get prst\n");
> +
> +     lvds->lvd_rstc = devm_reset_control_get_shared(dev, "lvdrst");
> +     if (IS_ERR(lvds->lvd_rstc))
> +             return dev_err_probe(dev, PTR_ERR(lvds->lvd_rstc),
> +                                  "failed to get core reset\n");
> +
> +     platform_set_drvdata(pdev, lvds);
> +     ret = devm_pm_runtime_enable(dev);
> +     if (ret)
> +             return dev_err_probe(dev, ret, "Failed to enable Runtime PM\n");
> +
> +     lvds->bridge.next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 1, 
> 0);
> +     if (IS_ERR(lvds->bridge.next_bridge))
> +             return dev_err_probe(dev, PTR_ERR(lvds->bridge.next_bridge),
> +                                  "failed to get next bridge\n");
> +
> +     ret = reset_control_assert(rstc);
> +     if (ret < 0)
> +             return ret;
> +
> +     ret = reset_control_assert(arstc);
> +     if (ret < 0)
> +             return ret;
> +
> +     ret = devm_drm_bridge_add(dev, &lvds->bridge);
> +     if (ret)
> +             return dev_err_probe(dev, ret,
> +                                  "Failed to register drm bridge\n");
> +
> +     return ret;
> +}
> +
> +static const struct of_device_id rzg3l_lvds_of_table[] = {
> +     { .compatible = "renesas,r9a08g046-lvds" },
> +     { /* sentinel */ }
> +};
> +
> +MODULE_DEVICE_TABLE(of, rzg3l_lvds_of_table);
> +
> +static struct platform_driver rzg3l_lvds_platform_driver = {
> +     .probe          = rzg3l_lvds_probe,
> +     .driver         = {
> +             .name   = "rzg3l-lvds",
> +             .pm     = pm_ptr(&rzg3l_lvds_pm_ops),
> +             .of_match_table = rzg3l_lvds_of_table,
> +     },
> +};
> +
> +module_platform_driver(rzg3l_lvds_platform_driver);
> +
> +MODULE_AUTHOR("Biju Das <[email protected]>");
> +MODULE_AUTHOR("Tommaso Merciai <[email protected]>");
> +MODULE_DESCRIPTION("Renesas RZ/G3L LVDS Encoder Driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h 
> b/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h
> new file mode 100644
> index 000000000000..281b7648f168
> --- /dev/null
> +++ b/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h
> @@ -0,0 +1,26 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * RZ/G3L LVDS Interface Registers Definitions
> + *
> + * Copyright (C) 2026 Renesas Electronics Corporation
> + *
> + */
> +
> +#ifndef __RZG3L_LVDS_REGS_H__
> +#define __RZG3L_LVDS_REGS_H__
> +
> +#define LVDS_CMN                     0x00
> +#define LVDS_CMN_RST_PHY0_SEL                (1 << 24)
> +#define LVDS_CMN_RST_PHY0_SEL_CH0    (1 << 24)
> +#define LVDS_CMN_PHY_RESET           (1 << 0)
> +
> +#define LVDS_0_PHY_OFFSET            0x10
> +#define LVDS_0_PHY_CH_IO_EN_MSK              (0x1f)
> +#define LVDS_0_PHY_CH_IO_EN          (LVDS_0_PHY_CH_IO_EN_MSK << 0)
> +#define LVDS_0_PHY_CH_EN_BGR         BIT(8)
> +#define LVDS_0_PHY_CH_EN_LDO         BIT(9)
> +
> +#define LVDS_0_CTL_OFFSET            0x14
> +#define LVDS_0_CTL_FMT_SEL_MSK               GENMASK(23, 20)
> +
> +#endif /* __RZG3L_LVDS_REGS_H__ */
> -- 
> 2.43.0
> 

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