On Thu, Jan 29, 2026 at 12:05:32PM +0800, Joey Lu wrote:
> Add DRM driver support for the Display Control Unit (DCU)
> found in Nuvoton MA35D1 SoCs.
>
> Signed-off-by: Joey Lu <[email protected]>
> ---
> drivers/gpu/drm/Kconfig | 1 +
> drivers/gpu/drm/Makefile | 1 +
> drivers/gpu/drm/nuvoton/Kconfig | 21 +
> drivers/gpu/drm/nuvoton/Makefile | 7 +
> drivers/gpu/drm/nuvoton/ma35_crtc.c | 372 ++++++++++++++
> drivers/gpu/drm/nuvoton/ma35_crtc.h | 67 +++
> drivers/gpu/drm/nuvoton/ma35_drm.c | 371 ++++++++++++++
> drivers/gpu/drm/nuvoton/ma35_drm.h | 48 ++
> drivers/gpu/drm/nuvoton/ma35_interface.c | 193 ++++++++
> drivers/gpu/drm/nuvoton/ma35_interface.h | 30 ++
> drivers/gpu/drm/nuvoton/ma35_plane.c | 603 +++++++++++++++++++++++
> drivers/gpu/drm/nuvoton/ma35_plane.h | 115 +++++
> drivers/gpu/drm/nuvoton/ma35_regs.h | 88 ++++
No maintainers? Why would we want to take unmaintained code?
> +static void ma35_mode_fini(struct ma35_drm *priv)
> +{
> + struct drm_device *drm_dev = &priv->drm_dev;
> +
> + drm_kms_helper_poll_fini(drm_dev);
> +}
> +
> +static int ma35_clocks_prepare(struct ma35_drm *priv)
> +{
> + struct drm_device *drm_dev = &priv->drm_dev;
> + struct device *dev = drm_dev->dev;
> + int ret;
> +
> + priv->dcuclk = devm_clk_get(dev, "dcu_gate");
> + if (IS_ERR(priv->dcuclk)) {
> + dev_err(dev, "Failed to get display core clock\n");
Don't spam logs on defers. Syntax is in entire probe path: return
dev_err_probe
> + return PTR_ERR(priv->dcuclk);
> + }
> +
> + ret = clk_prepare_enable(priv->dcuclk);
Why this cannot be devm_clk_get_enabled?
> + if (ret) {
> + dev_err(dev, "Failed to enable display core clock\n");
> + return ret;
> + }
> +
> + priv->dcupclk = devm_clk_get(dev, "dcup_div");
> + if (IS_ERR(priv->dcupclk)) {
> + dev_err(dev, "Failed to get display pixel clock\n");
> + return PTR_ERR(priv->dcupclk);
> + }
> +
> + ret = clk_prepare_enable(priv->dcupclk);
> + if (ret) {
> + dev_err(dev, "Failed to enable display pixel clock\n");
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int ma35_clocks_unprepare(struct ma35_drm *priv)
> +{
> + struct clk **clocks[] = {
> + &priv->dcuclk,
> + &priv->dcupclk,
> + };
> + unsigned int i;
> +
> + for (i = 0; i < ARRAY_SIZE(clocks); i++) {
> + if (!*clocks[i])
> + continue;
> +
> + clk_disable_unprepare(*clocks[i]);
> + *clocks[i] = NULL;
Huh, pretty complicated and pointless code. This should be devm and bulk
API...
> + }
> +
> + return 0;
> +}
> +
> +static int ma35_drm_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct ma35_drm *priv;
> + struct drm_device *drm_dev;
> + void __iomem *base;
> + struct regmap *regmap = NULL;
> + int irq;
> + int ret;
> +
> + ret = of_reserved_mem_device_init(dev);
> + if (ret && ret != -ENODEV) {
> + dev_err(dev, "Failed to get optional reserved memory: %d\n",
> ret);
> + return ret;
> + }
> +
> + base = devm_platform_ioremap_resource(pdev, 0);
> + if (IS_ERR(base)) {
> + dev_err(dev, "Failed to map I/O base\n");
Why aren't you using dev_err_probe?
> + ret = PTR_ERR(base);
> + goto error_reserved_mem;
> + }
> + regmap = devm_regmap_init_mmio(dev, base, &ma35_drm_regmap_config);
> + if (IS_ERR(regmap)) {
> + dev_err(dev, "Failed to create regmap for I/O\n");
> + ret = PTR_ERR(regmap);
> + goto error_reserved_mem;
> + }
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0) {
> + ret = -ENODEV;
> + goto error_reserved_mem;
> + }
> +
> + priv = devm_drm_dev_alloc(dev, &ma35_drm_driver,
> + struct ma35_drm, drm_dev);
> + if (IS_ERR(priv)) {
> + ret = PTR_ERR(priv);
> + goto error_reserved_mem;
> + }
> +
> + platform_set_drvdata(pdev, priv);
> + drm_dev = &priv->drm_dev;
> + priv->regmap = regmap;
> + INIT_LIST_HEAD(&priv->layers_list);
> +
> + ret = ma35_clocks_prepare(priv);
> + if (ret) {
> + drm_err(drm_dev, "Failed to prepare clocks\n");
Why do you print error twice? Once in the function, second time here?
> + goto error_reserved_mem;
> + }
> +
> + ret = devm_request_irq(dev, irq, ma35_drm_irq_handler, 0,
> + dev_name(dev), priv);
> + if (ret) {
> + drm_err(drm_dev, "Failed to request IRQ\n");
> + goto error_clocks;
> + }
> +
> + /* modeset */
> + ret = ma35_mode_init(priv);
> + if (ret) {
> + drm_err(drm_dev, "Failed to initialize KMS\n");
> + goto error_clocks;
> + }
> +
> + /* plane */
> + ret = ma35_plane_init(priv);
> + if (ret) {
> + drm_err(drm_dev, "Failed to initialize layers\n");
> + goto error_clocks;
> + }
> +
> + /* crtc */
> + ret = ma35_crtc_init(priv);
> + if (ret) {
> + drm_err(drm_dev, "Failed to initialize CRTC\n");
> + goto error_clocks;
> + }
> +
> + /* interface */
> + ret = ma35_interface_init(priv);
> + if (ret) {
> + if (ret != -EPROBE_DEFER)
> + drm_err(drm_dev, "Failed to initialize interface\n");
> +
> + goto error_clocks;
> + }
> +
> + drm_mode_config_reset(drm_dev);
> +
> + ret = drm_dev_register(drm_dev, 0);
> + if (ret) {
> + drm_err(drm_dev, "Failed to register DRM device\n");
> + goto error_mode;
> + }
> +
> + drm_client_setup(drm_dev, NULL);
Best regards,
Krzysztof
