Re: [PATCH AUTOSEL 5.4 07/15] drm/sun4i: dw-hdmi: Make HDMI PHY into a platform device

[Saravana Kannan <saravanak@google.com>]

On Tue, Jun 15, 2021 at 8:50 AM Sasha Levin <sashal@kernel.org> wrote:
>
> From: Saravana Kannan <saravanak@google.com>
>
> [ Upstream commit 9bf3797796f570b34438235a6a537df85832bdad ]
>
> On sunxi boards that use HDMI output, HDMI device probe keeps being
> avoided indefinitely with these repeated messages in dmesg:
>
>   platform 1ee0000.hdmi: probe deferral - supplier 1ef0000.hdmi-phy
>     not ready
>
> There's a fwnode_link being created with fw_devlink=on between hdmi
> and hdmi-phy nodes, because both nodes have 'compatible' property set.
>
> Fw_devlink code assumes that nodes that have compatible property
> set will also have a device associated with them by some driver
> eventually. This is not the case with the current sun8i-hdmi
> driver.
>

fw_devlink isn't present in 5.4 or earlier. So technically this patch
isn't needed.

-Saravana

> This commit makes sun8i-hdmi-phy into a proper platform device
> and fixes the display pipeline probe on sunxi boards that use HDMI.
>
> More context: https://lkml.org/lkml/2021/5/16/203
>
> Signed-off-by: Saravana Kannan <saravanak@google.com>
> Signed-off-by: Ondrej Jirman <megous@megous.com>
> Tested-by: Andre Przywara <andre.przywara@arm.com>
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> Link: https://patchwork.freedesktop.org/patch/msgid/20210607085836.2827429-1-megous@megous.com
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
>  drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c  | 31 ++++++++++++++++---
>  drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h  |  5 ++--
>  drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c | 41 ++++++++++++++++++++++----
>  3 files changed, 66 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
> index 8f721be26477..cfb63cae4b12 100644
> --- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
> +++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
> @@ -211,7 +211,7 @@ static int sun8i_dw_hdmi_bind(struct device *dev, struct device *master,
>                 goto err_disable_clk_tmds;
>         }
>
> -       ret = sun8i_hdmi_phy_probe(hdmi, phy_node);
> +       ret = sun8i_hdmi_phy_get(hdmi, phy_node);
>         of_node_put(phy_node);
>         if (ret) {
>                 dev_err(dev, "Couldn't get the HDMI PHY\n");
> @@ -244,7 +244,6 @@ static int sun8i_dw_hdmi_bind(struct device *dev, struct device *master,
>
>  cleanup_encoder:
>         drm_encoder_cleanup(encoder);
> -       sun8i_hdmi_phy_remove(hdmi);
>  err_disable_clk_tmds:
>         clk_disable_unprepare(hdmi->clk_tmds);
>  err_assert_ctrl_reset:
> @@ -265,7 +264,6 @@ static void sun8i_dw_hdmi_unbind(struct device *dev, struct device *master,
>         struct sun8i_dw_hdmi *hdmi = dev_get_drvdata(dev);
>
>         dw_hdmi_unbind(hdmi->hdmi);
> -       sun8i_hdmi_phy_remove(hdmi);
>         clk_disable_unprepare(hdmi->clk_tmds);
>         reset_control_assert(hdmi->rst_ctrl);
>         gpiod_set_value(hdmi->ddc_en, 0);
> @@ -322,7 +320,32 @@ static struct platform_driver sun8i_dw_hdmi_pltfm_driver = {
>                 .of_match_table = sun8i_dw_hdmi_dt_ids,
>         },
>  };
> -module_platform_driver(sun8i_dw_hdmi_pltfm_driver);
> +
> +static int __init sun8i_dw_hdmi_init(void)
> +{
> +       int ret;
> +
> +       ret = platform_driver_register(&sun8i_dw_hdmi_pltfm_driver);
> +       if (ret)
> +               return ret;
> +
> +       ret = platform_driver_register(&sun8i_hdmi_phy_driver);
> +       if (ret) {
> +               platform_driver_unregister(&sun8i_dw_hdmi_pltfm_driver);
> +               return ret;
> +       }
> +
> +       return ret;
> +}
> +
> +static void __exit sun8i_dw_hdmi_exit(void)
> +{
> +       platform_driver_unregister(&sun8i_dw_hdmi_pltfm_driver);
> +       platform_driver_unregister(&sun8i_hdmi_phy_driver);
> +}
> +
> +module_init(sun8i_dw_hdmi_init);
> +module_exit(sun8i_dw_hdmi_exit);
>
>  MODULE_AUTHOR("Jernej Skrabec <jernej.skrabec@siol.net>");
>  MODULE_DESCRIPTION("Allwinner DW HDMI bridge");
> diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
> index d707c9171824..5a299a6f5aa5 100644
> --- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
> +++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
> @@ -194,14 +194,15 @@ struct sun8i_dw_hdmi {
>         struct gpio_desc                *ddc_en;
>  };
>
> +extern struct platform_driver sun8i_hdmi_phy_driver;
> +
>  static inline struct sun8i_dw_hdmi *
>  encoder_to_sun8i_dw_hdmi(struct drm_encoder *encoder)
>  {
>         return container_of(encoder, struct sun8i_dw_hdmi, encoder);
>  }
>
> -int sun8i_hdmi_phy_probe(struct sun8i_dw_hdmi *hdmi, struct device_node *node);
> -void sun8i_hdmi_phy_remove(struct sun8i_dw_hdmi *hdmi);
> +int sun8i_hdmi_phy_get(struct sun8i_dw_hdmi *hdmi, struct device_node *node);
>
>  void sun8i_hdmi_phy_init(struct sun8i_hdmi_phy *phy);
>  void sun8i_hdmi_phy_set_ops(struct sun8i_hdmi_phy *phy,
> diff --git a/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c b/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c
> index a4012ec13d4b..c6289328c874 100644
> --- a/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c
> +++ b/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c
> @@ -5,6 +5,7 @@
>
>  #include <linux/delay.h>
>  #include <linux/of_address.h>
> +#include <linux/of_platform.h>
>
>  #include "sun8i_dw_hdmi.h"
>
> @@ -596,10 +597,30 @@ static const struct of_device_id sun8i_hdmi_phy_of_table[] = {
>         { /* sentinel */ }
>  };
>
> -int sun8i_hdmi_phy_probe(struct sun8i_dw_hdmi *hdmi, struct device_node *node)
> +int sun8i_hdmi_phy_get(struct sun8i_dw_hdmi *hdmi, struct device_node *node)
> +{
> +       struct platform_device *pdev = of_find_device_by_node(node);
> +       struct sun8i_hdmi_phy *phy;
> +
> +       if (!pdev)
> +               return -EPROBE_DEFER;
> +
> +       phy = platform_get_drvdata(pdev);
> +       if (!phy)
> +               return -EPROBE_DEFER;
> +
> +       hdmi->phy = phy;
> +
> +       put_device(&pdev->dev);
> +
> +       return 0;
> +}
> +
> +static int sun8i_hdmi_phy_probe(struct platform_device *pdev)
>  {
>         const struct of_device_id *match;
> -       struct device *dev = hdmi->dev;
> +       struct device *dev = &pdev->dev;
> +       struct device_node *node = dev->of_node;
>         struct sun8i_hdmi_phy *phy;
>         struct resource res;
>         void __iomem *regs;
> @@ -703,7 +724,7 @@ int sun8i_hdmi_phy_probe(struct sun8i_dw_hdmi *hdmi, struct device_node *node)
>                 clk_prepare_enable(phy->clk_phy);
>         }
>
> -       hdmi->phy = phy;
> +       platform_set_drvdata(pdev, phy);
>
>         return 0;
>
> @@ -727,9 +748,9 @@ int sun8i_hdmi_phy_probe(struct sun8i_dw_hdmi *hdmi, struct device_node *node)
>         return ret;
>  }
>
> -void sun8i_hdmi_phy_remove(struct sun8i_dw_hdmi *hdmi)
> +static int sun8i_hdmi_phy_remove(struct platform_device *pdev)
>  {
> -       struct sun8i_hdmi_phy *phy = hdmi->phy;
> +       struct sun8i_hdmi_phy *phy = platform_get_drvdata(pdev);
>
>         clk_disable_unprepare(phy->clk_mod);
>         clk_disable_unprepare(phy->clk_bus);
> @@ -743,4 +764,14 @@ void sun8i_hdmi_phy_remove(struct sun8i_dw_hdmi *hdmi)
>         clk_put(phy->clk_pll1);
>         clk_put(phy->clk_mod);
>         clk_put(phy->clk_bus);
> +       return 0;
>  }
> +
> +struct platform_driver sun8i_hdmi_phy_driver = {
> +       .probe  = sun8i_hdmi_phy_probe,
> +       .remove = sun8i_hdmi_phy_remove,
> +       .driver = {
> +               .name = "sun8i-hdmi-phy",
> +               .of_match_table = sun8i_hdmi_phy_of_table,
> +       },
> +};
> --
> 2.30.2
>