Re: [PATCH v12 3/7] drm/sun4i: dsi: Add has_mod_clk quirk

Chen-Yu Tsai
2019-12-03T14:39:56Z

On Tue, Dec 3, 2019 at 9:48 PM Jagan Teki <jagan@amarulasolutions.com> wrote:
>
> As per the user manual, look like mod clock is not mandatory
> for all Allwinner MIPI DSI controllers, it is connected to
> CLK_DSI_SCLK for A31 and not available in A64.
>
> So add has_mod_clk quirk and process the mod clk accordingly.
>
> Tested-by: Merlijn Wajer <merlijn@wizzup.org>
> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> ---
> Changes for v12:
> - none
>
> drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 38 ++++++++++++++++++--------
> drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h | 5 ++++
> 2 files changed, 32 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> index c958ca9bae63..8c4c541224dd 100644
> --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> @@ -11,6 +11,7 @@
> #include <linux/crc-ccitt.h>
> #include <linux/module.h>
> #include <linux/of_address.h>
> +#include <linux/of_device.h>
> #include <linux/phy/phy-mipi-dphy.h>
> #include <linux/phy/phy.h>
> #include <linux/platform_device.h>
> @@ -1093,6 +1094,7 @@ static int sun6i_dsi_probe(struct platform_device *pdev)
> dsi->dev = dev;
> dsi->host.ops = &sun6i_dsi_host_ops;
> dsi->host.dev = dev;
> + dsi->variant = of_device_get_match_data(dev);
>
> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> base = devm_ioremap_resource(dev, res);
> @@ -1120,17 +1122,20 @@ static int sun6i_dsi_probe(struct platform_device *pdev)
> return PTR_ERR(dsi->reset);
> }
>
> - dsi->mod_clk = devm_clk_get(dev, "mod");
> - if (IS_ERR(dsi->mod_clk)) {
> - dev_err(dev, "Couldn't get the DSI mod clock\n");
> - return PTR_ERR(dsi->mod_clk);
> + if (dsi->variant->has_mod_clk) {
> + dsi->mod_clk = devm_clk_get(dev, "mod");
> + if (IS_ERR(dsi->mod_clk)) {
> + dev_err(dev, "Couldn't get the DSI mod clock\n");
> + return PTR_ERR(dsi->mod_clk);
> + }
> }
>
> /*
> * In order to operate properly, that clock seems to be always
> * set to 297MHz.
> */
> - clk_set_rate_exclusive(dsi->mod_clk, 297000000);
> + if (dsi->variant->has_mod_clk)
> + clk_set_rate_exclusive(dsi->mod_clk, 297000000);

The clk API can handle NULL pointers, so you don't need to add the if here...

>
> dsi->dphy = devm_phy_get(dev, "dphy");
> if (IS_ERR(dsi->dphy)) {
> @@ -1160,7 +1165,8 @@ static int sun6i_dsi_probe(struct platform_device *pdev)
> err_pm_disable:
> pm_runtime_disable(dev);
> err_unprotect_clk:
> - clk_rate_exclusive_put(dsi->mod_clk);
> + if (dsi->variant->has_mod_clk)
> + clk_rate_exclusive_put(dsi->mod_clk);

and here...

> return ret;
> }
>
> @@ -1172,7 +1178,8 @@ static int sun6i_dsi_remove(struct platform_device *pdev)
> component_del(&pdev->dev, &sun6i_dsi_ops);
> mipi_dsi_host_unregister(&dsi->host);
> pm_runtime_disable(dev);
> - clk_rate_exclusive_put(dsi->mod_clk);
> + if (dsi->variant->has_mod_clk)
> + clk_rate_exclusive_put(dsi->mod_clk);

and here ...

>
> return 0;
> }
> @@ -1189,7 +1196,8 @@ static int __maybe_unused sun6i_dsi_runtime_resume(struct device *dev)
> }
>
> reset_control_deassert(dsi->reset);
> - clk_prepare_enable(dsi->mod_clk);
> + if (dsi->variant->has_mod_clk)
> + clk_prepare_enable(dsi->mod_clk);

and here...

>
> /*
> * Enable the DSI block.
> @@ -1217,7 +1225,8 @@ static int __maybe_unused sun6i_dsi_runtime_suspend(struct device *dev)
> {
> struct sun6i_dsi *dsi = dev_get_drvdata(dev);
>
> - clk_disable_unprepare(dsi->mod_clk);
> + if (dsi->variant->has_mod_clk)
> + clk_disable_unprepare(dsi->mod_clk);

and here.

> reset_control_assert(dsi->reset);
> regulator_disable(dsi->regulator);
>
> @@ -1230,9 +1239,16 @@ static const struct dev_pm_ops sun6i_dsi_pm_ops = {
> NULL)
> };
>
> +static const struct sun6i_dsi_variant sun6i_a31_mipi_dsi = {
> + .has_mod_clk = true,
> +};
> +
> static const struct of_device_id sun6i_dsi_of_table[] = {
> - { .compatible = "allwinner,sun6i-a31-mipi-dsi" },
> - { }
> + {
> + .compatible = "allwinner,sun6i-a31-mipi-dsi",
> + .data = &sun6i_a31_mipi_dsi,
> + },
> + { /* sentinel */ }
> };
> MODULE_DEVICE_TABLE(of, sun6i_dsi_of_table);
>
> diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
> index 3f4846f581ef..d791c9f6fccf 100644
> --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
> +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
> @@ -15,6 +15,10 @@
>
> #define SUN6I_DSI_TCON_DIV 4
>
> +struct sun6i_dsi_variant {
> + bool has_mod_clk;
> +};
> +

You could choose to put this above the probe function, since this isn't used
anywhere else, and a pointer field doesn't need the full definition.

ChenYu

> struct sun6i_dsi {
> struct drm_connector connector;
> struct drm_encoder encoder;
> @@ -31,6 +35,7 @@ struct sun6i_dsi {
> struct sun4i_drv *drv;
> struct mipi_dsi_device *device;
> struct drm_panel *panel;
> + const struct sun6i_dsi_variant *variant;
> };
>
> static inline struct sun6i_dsi *host_to_sun6i_dsi(struct mipi_dsi_host *host)
> --
> 2.18.0.321.gffc6fa0e3
>