Re: [PATCH v2 22/66] media: sun6i-csi: Use runtime pm for clocks and reset

Maxime Ripard
2022-02-09T10:16:55Z

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On Sat, Feb 05, 2022 at 07:53:45PM +0100, Paul Kocialkowski wrote:
> Wrap the clock and reset preparation into runtime pm functions
> for better organization of the code.
>
> Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> ---
> .../platform/sunxi/sun6i-csi/sun6i_csi.c | 94 ++++++++++++++-----
> 1 file changed, 69 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> index 2355088fdc37..b53b92b70a89 100644
> --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> @@ -152,40 +152,18 @@ int sun6i_csi_set_power(struct sun6i_csi_device *csi_dev, bool enable)
>
> if (!enable) {
> regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN, 0);
> + pm_runtime_put(dev);
>
> - clk_disable_unprepare(csi_dev->clk_ram);
> - clk_disable_unprepare(csi_dev->clk_mod);
> - reset_control_assert(csi_dev->reset);
> return 0;
> }
>
> - ret = clk_prepare_enable(csi_dev->clk_mod);
> - if (ret) {
> - dev_err(csi_dev->dev, "Enable csi clk err %d\n", ret);
> + ret = pm_runtime_resume_and_get(dev);
> + if (ret < 0)
> return ret;
> - }
> -
> - ret = clk_prepare_enable(csi_dev->clk_ram);
> - if (ret) {
> - dev_err(csi_dev->dev, "Enable clk_dram_csi clk err %d\n", ret);
> - goto clk_mod_disable;
> - }
> -
> - ret = reset_control_deassert(csi_dev->reset);
> - if (ret) {
> - dev_err(csi_dev->dev, "reset err %d\n", ret);
> - goto clk_ram_disable;
> - }
>
> regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN, CSI_EN_CSI_EN);
>
> return 0;
> -
> -clk_ram_disable:
> - clk_disable_unprepare(csi_dev->clk_ram);
> -clk_mod_disable:
> - clk_disable_unprepare(csi_dev->clk_mod);
> - return ret;
> }
>
> static enum csi_input_fmt get_csi_input_format(struct sun6i_csi_device *csi_dev,
> @@ -800,6 +778,65 @@ static irqreturn_t sun6i_csi_isr(int irq, void *private)
> return IRQ_HANDLED;
> }
>
> +static int sun6i_csi_suspend(struct device *dev)
> +{
> + struct sun6i_csi_device *csi_dev = dev_get_drvdata(dev);
> +
> + reset_control_assert(csi_dev->reset);
> + clk_disable_unprepare(csi_dev->clk_ram);
> + clk_disable_unprepare(csi_dev->clk_mod);
> + clk_disable_unprepare(csi_dev->clk_bus);
> +
> + return 0;
> +}
> +
> +static int sun6i_csi_resume(struct device *dev)
> +{
> + struct sun6i_csi_device *csi_dev = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = reset_control_deassert(csi_dev->reset);
> + if (ret) {
> + dev_err(dev, "failed to deassert reset\n");
> + return ret;
> + }
> +
> + ret = clk_prepare_enable(csi_dev->clk_bus);
> + if (ret) {
> + dev_err(dev, "failed to enable bus clock\n");
> + goto error_reset;
> + }
> +
> + ret = clk_prepare_enable(csi_dev->clk_mod);
> + if (ret) {
> + dev_err(dev, "failed to enable module clock\n");
> + goto error_clk_bus;
> + }
> +
> + ret = clk_prepare_enable(csi_dev->clk_ram);
> + if (ret) {
> + dev_err(dev, "failed to enable ram clock\n");
> + goto error_clk_mod;
> + }
> +
> + return 0;

You've change the order of the reset vs clock initialization. Also, does
that work with CONFIG_PM disabled?

Maxime

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