Re: [PATCH 04/12] drm/sun4i: sun6i_mipi_dsi: Enable missing DSI bus clock

Chen-Yu Tsai
2018-09-27T12:43:11Z

Hi,

On Thu, Sep 27, 2018 at 7:49 PM Jagan Teki <jagan@amarulasolutions.com> wrote:
>
> DSI bus_clk is already available in sun6i_dsi but missed to
> get the clk and process for enable/disable.
>
> This patch add support for it.
>
> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> ---
> drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> index 8e9c76febca2..156b371243c6 100644
> --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> @@ -1004,6 +1004,12 @@ static int sun6i_dsi_probe(struct platform_device *pdev)
> return PTR_ERR(dsi->reset);
> }
>
> + dsi->bus_clk = devm_clk_get(dev, "bus");
> + if (IS_ERR(dsi->bus_clk)) {
> + dev_err(dev, "Couldn't get the DSI bus clock\n");
> + return PTR_ERR(dsi->bus_clk);
> + }
> +

The DSI driver uses devm_regmap_init_mmio_clk, which enables the
clock behind the scenes when regmap access needs it enabled.

Did you have any issues without this patch?

ChenYu

> if (dsi->variant->has_mod_clk) {
> dsi->mod_clk = devm_clk_get(dev, "mod");
> if (IS_ERR(dsi->mod_clk)) {
> @@ -1012,6 +1018,7 @@ static int sun6i_dsi_probe(struct platform_device *pdev)
> }
> }
>
> + clk_prepare_enable(dsi->bus_clk);
> /*
> * In order to operate properly, that clock seems to be always
> * set to 297MHz.
> @@ -1065,6 +1072,7 @@ static int sun6i_dsi_remove(struct platform_device *pdev)
> sun6i_dphy_remove(dsi);
> if (dsi->variant->has_mod_clk)
> clk_rate_exclusive_put(dsi->mod_clk);
> + clk_disable_unprepare(dsi->bus_clk);
>
> return 0;
> }
> --
> 2.18.0.321.gffc6fa0e3
>