RE: [PATCH 11/17] drm: renesas: rz-du: mipi_dsi: Add OF data support

Biju Das
2025-03-31T12:38:37Z

Hi Prabhakar,

Thanks for the patch.

> -----Original Message-----
> From: Prabhakar <prabhakar.csengg@gmail.com>
> Sent: 30 March 2025 22:07
> Subject: [PATCH 11/17] drm: renesas: rz-du: mipi_dsi: Add OF data support
>
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>
> In preparation for adding support for the Renesas RZ/V2H(P) SoC, this patch introduces a mechanism to
> pass SoC-specific information via OF data in the DSI driver. This enables the driver to adapt
> dynamically to various SoC-specific requirements without hardcoding configurations.
>
> The MIPI DSI interface on the RZ/V2H(P) SoC is nearly identical to the one on the RZ/G2L SoC. While
> the LINK registers are shared between the two SoCs, the D-PHY registers differ. Also the VCLK range
> differs on both these SoCs. To accommodate these differences `struct rzg2l_mipi_dsi_hw_info` is
> introduced and as now passed as OF data.
>
> These changes lay the groundwork for the upcoming RZ/V2H(P) SoC support by allowing SoC-specific data
> to be passed through OF.
>
> Co-developed-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
> Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
> .../gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c | 66 ++++++++++++++-----
> .../drm/renesas/rz-du/rzg2l_mipi_dsi_regs.h | 2 -
> 2 files changed, 49 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c b/drivers/gpu/drm/renesas/rz-
> du/rzg2l_mipi_dsi.c
> index e0379f099659..44b95082b29c 100644
> --- a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
> +++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
> @@ -28,10 +28,24 @@
>
> #include "rzg2l_mipi_dsi_regs.h"
>
> +struct rzg2l_mipi_dsi;
> +
> +struct rzg2l_mipi_dsi_hw_info {
> + int (*dphy_init)(struct rzg2l_mipi_dsi *dsi, unsigned long hsfreq);
> + void (*dphy_exit)(struct rzg2l_mipi_dsi *dsi);
> + u32 phy_reg_offset;
> + u32 link_reg_offset;
> + unsigned long max_dclk;
> + unsigned long min_dclk;
> + bool has_dphy_rstc;
> +};
> +
> struct rzg2l_mipi_dsi {
> struct device *dev;
> void __iomem *mmio;
>
> + const struct rzg2l_mipi_dsi_hw_info *info;
> +
> struct reset_control *rstc;
> struct reset_control *arstc;
> struct reset_control *prstc;
> @@ -164,22 +178,22 @@ static const struct rzg2l_mipi_dsi_timings rzg2l_mipi_dsi_global_timings[] = {
>
> static void rzg2l_mipi_dsi_phy_write(struct rzg2l_mipi_dsi *dsi, u32 reg, u32 data) {
> - iowrite32(data, dsi->mmio + reg);
> + iowrite32(data, dsi->mmio + dsi->info->phy_reg_offset + reg);
> }
>
> static void rzg2l_mipi_dsi_link_write(struct rzg2l_mipi_dsi *dsi, u32 reg, u32 data) {
> - iowrite32(data, dsi->mmio + LINK_REG_OFFSET + reg);
> + iowrite32(data, dsi->mmio + dsi->info->link_reg_offset + reg);
> }
>
> static u32 rzg2l_mipi_dsi_phy_read(struct rzg2l_mipi_dsi *dsi, u32 reg) {
> - return ioread32(dsi->mmio + reg);
> + return ioread32(dsi->mmio + dsi->info->phy_reg_offset + reg);
> }
>
> static u32 rzg2l_mipi_dsi_link_read(struct rzg2l_mipi_dsi *dsi, u32 reg) {
> - return ioread32(dsi->mmio + LINK_REG_OFFSET + reg);
> + return ioread32(dsi->mmio + dsi->info->link_reg_offset + reg);
> }
>
> /* -----------------------------------------------------------------------------
> @@ -291,7 +305,7 @@ static int rzg2l_mipi_dsi_startup(struct rzg2l_mipi_dsi *dsi,
> vclk_rate = clk_get_rate(dsi->vclk);
> hsfreq = DIV_ROUND_CLOSEST_ULL(vclk_rate * bpp, dsi->lanes);
>
> - ret = rzg2l_mipi_dsi_dphy_init(dsi, hsfreq);
> + ret = dsi->info->dphy_init(dsi, hsfreq);
> if (ret < 0)
> goto err_phy;
>
> @@ -334,7 +348,7 @@ static int rzg2l_mipi_dsi_startup(struct rzg2l_mipi_dsi *dsi,
> return 0;
>
> err_phy:
> - rzg2l_mipi_dsi_dphy_exit(dsi);
> + dsi->info->dphy_exit(dsi);
> pm_runtime_put(dsi->dev);
>
> return ret;
> @@ -342,7 +356,7 @@ static int rzg2l_mipi_dsi_startup(struct rzg2l_mipi_dsi *dsi,
>
> static void rzg2l_mipi_dsi_stop(struct rzg2l_mipi_dsi *dsi) {
> - rzg2l_mipi_dsi_dphy_exit(dsi);
> + dsi->info->dphy_exit(dsi);
> pm_runtime_put(dsi->dev);
> }
>
> @@ -585,10 +599,12 @@ rzg2l_mipi_dsi_bridge_mode_valid(struct drm_bridge *bridge,
> const struct drm_display_info *info,
> const struct drm_display_mode *mode) {
> - if (mode->clock > 148500)
> + struct rzg2l_mipi_dsi *dsi = bridge_to_rzg2l_mipi_dsi(bridge);
> +
> + if (mode->clock > dsi->info->max_dclk)
> return MODE_CLOCK_HIGH;
>
> - if (mode->clock < 5803)
> + if (mode->clock < dsi->info->min_dclk)
> return MODE_CLOCK_LOW;
>
> return MODE_OK;
> @@ -714,6 +730,11 @@ static int rzg2l_mipi_dsi_probe(struct platform_device *pdev)
> platform_set_drvdata(pdev, dsi);
> dsi->dev = &pdev->dev;
>
> + dsi->info = of_device_get_match_data(&pdev->dev);
> + if (!dsi->info)
> + return dev_err_probe(dsi->dev, -ENODEV,
> + "missing data info\n");
> +
> ret = drm_of_get_data_lanes_count_ep(dsi->dev->of_node, 1, 0, 1, 4);
> if (ret < 0)
> return dev_err_probe(dsi->dev, ret,
> @@ -729,10 +750,12 @@ static int rzg2l_mipi_dsi_probe(struct platform_device *pdev)
> if (IS_ERR(dsi->vclk))
> return PTR_ERR(dsi->vclk);
>
> - dsi->rstc = devm_reset_control_get_exclusive(dsi->dev, "rst");
> - if (IS_ERR(dsi->rstc))
> - return dev_err_probe(dsi->dev, PTR_ERR(dsi->rstc),
> - "failed to get rst\n");
> + if (dsi->info->has_dphy_rstc) {
> + dsi->rstc = devm_reset_control_get_exclusive(dsi->dev, "rst");

Maybe use devm_reset_control_get_optional_exclusive by dropping has_dphy_rstc.

Cheers,
Biju

> + if (IS_ERR(dsi->rstc))
> + return dev_err_probe(dsi->dev, PTR_ERR(dsi->rstc),
> + "failed to get rst\n");
> + }
>
> dsi->arstc = devm_reset_control_get_exclusive(dsi->dev, "arst");
> if (IS_ERR(dsi->arstc))
> @@ -757,13 +780,13 @@ static int rzg2l_mipi_dsi_probe(struct platform_device *pdev)
> * mode->clock and format are not available. So initialize DPHY with
> * timing parameters for 80Mbps.
> */
> - ret = rzg2l_mipi_dsi_dphy_init(dsi, 80000000);
> + ret = dsi->info->dphy_init(dsi, 80000000);
> if (ret < 0)
> goto err_phy;
>
> txsetr = rzg2l_mipi_dsi_link_read(dsi, TXSETR);
> dsi->num_data_lanes = min(((txsetr >> 16) & 3) + 1, num_data_lanes);
> - rzg2l_mipi_dsi_dphy_exit(dsi);
> + dsi->info->dphy_exit(dsi);
> pm_runtime_put(dsi->dev);
>
> /* Initialize the DRM bridge. */
> @@ -780,7 +803,7 @@ static int rzg2l_mipi_dsi_probe(struct platform_device *pdev)
> return 0;
>
> err_phy:
> - rzg2l_mipi_dsi_dphy_exit(dsi);
> + dsi->info->dphy_exit(dsi);
> pm_runtime_put(dsi->dev);
> err_pm_disable:
> pm_runtime_disable(dsi->dev);
> @@ -795,8 +818,17 @@ static void rzg2l_mipi_dsi_remove(struct platform_device *pdev)
> pm_runtime_disable(&pdev->dev);
> }
>
> +static const struct rzg2l_mipi_dsi_hw_info rzg2l_mipi_dsi_info = {
> + .dphy_init = rzg2l_mipi_dsi_dphy_init,
> + .dphy_exit = rzg2l_mipi_dsi_dphy_exit,
> + .has_dphy_rstc = true,
> + .link_reg_offset = 0x10000,
> + .max_dclk = 148500,
> + .min_dclk = 5803,
> +};
> +
> static const struct of_device_id rzg2l_mipi_dsi_of_table[] = {
> - { .compatible = "renesas,rzg2l-mipi-dsi" },
> + { .compatible = "renesas,rzg2l-mipi-dsi", .data =
> +&rzg2l_mipi_dsi_info, },
> { /* sentinel */ }
> };
>
> diff --git a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi_regs.h b/drivers/gpu/drm/renesas/rz-
> du/rzg2l_mipi_dsi_regs.h
> index 1dbc16ec64a4..16efe4dc59f4 100644
> --- a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi_regs.h
> +++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi_regs.h
> @@ -41,8 +41,6 @@
> #define DSIDPHYTIM3_THS_ZERO(x) ((x) << 0)
>
> /* --------------------------------------------------------*/
> -/* Link Registers */
> -#define LINK_REG_OFFSET 0x10000
>
> /* Link Status Register */
> #define LINKSR 0x10
> --
> 2.49.0