Re: [PATCH v3 07/46] media: sun6i-csi: Use runtime pm for clocks and reset

Jernej Škrabec
2022-03-15T19:47:07Z

Dne petek, 11. marec 2022 ob 15:34:53 CET je Paul Kocialkowski napisal(a):
> Wrap the clock and reset preparation into runtime pm functions
> for better organization of the code. Also fix the clock and
> reset enable order to first deassert reset, as recommended in
> Allwinner litterature.
>
> Make the driver depend on PM while at it since runtime pm is
> mandatory for the driver to work.
>
> Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> ---
> .../media/platform/sunxi/sun6i-csi/Kconfig | 2 +-
> .../platform/sunxi/sun6i-csi/sun6i_csi.c | 94 ++++++++++++++-----
> 2 files changed, 70 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/media/platform/sunxi/sun6i-csi/Kconfig b/drivers/media/
platform/sunxi/sun6i-csi/Kconfig
> index 586e3fb3a80d..fd03e48f0c8a 100644
> --- a/drivers/media/platform/sunxi/sun6i-csi/Kconfig
> +++ b/drivers/media/platform/sunxi/sun6i-csi/Kconfig
> @@ -1,7 +1,7 @@
> # SPDX-License-Identifier: GPL-2.0-only
> config VIDEO_SUN6I_CSI
> tristate "Allwinner V3s Camera Sensor Interface driver"
> - depends on VIDEO_V4L2 && COMMON_CLK && HAS_DMA
> + depends on PM && VIDEO_V4L2 && COMMON_CLK && HAS_DMA
> depends on ARCH_SUNXI || COMPILE_TEST
> select MEDIA_CONTROLLER
> select VIDEO_V4L2_SUBDEV_API
> diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/
media/platform/sunxi/sun6i-csi/sun6i_csi.c
> index 4a0d08e0ac25..7f045a9551a7 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;
> +
> +error_clk_mod:
> + clk_disable_unprepare(csi_dev->clk_mod);
> +
> +error_clk_bus:
> + clk_disable_unprepare(csi_dev->clk_bus);
> +
> +error_reset:
> + reset_control_assert(csi_dev->reset);
> +
> + return ret;
> +}
> +
> +static const struct dev_pm_ops sun6i_csi_pm_ops = {
> + SET_RUNTIME_PM_OPS(sun6i_csi_suspend, sun6i_csi_resume, NULL)

Since driver depends on PM, using SET_RUNTIME_PM_OPS macro doesn't make sense.

> +};
> +
> static const struct regmap_config sun6i_csi_regmap_config = {
> .reg_bits = 32,
> .reg_stride = 4,
> @@ -886,6 +923,11 @@ static int sun6i_csi_resources_setup(struct
sun6i_csi_device *csi_dev,
> goto error_clk_rate_exclusive;
> }
>
> + /* Runtime PM */
> +
> + pm_runtime_enable(dev);
> + pm_runtime_set_suspended(dev);

pm_runtime_set_suspended() description says: "It is not valid to call this
function for devices with runtime PM enabled."

Best regards,
Jernej

> +
> return 0;
>
> error_clk_rate_exclusive:
> @@ -896,6 +938,7 @@ static int sun6i_csi_resources_setup(struct
sun6i_csi_device *csi_dev,
>
> static void sun6i_csi_resources_cleanup(struct sun6i_csi_device *csi_dev)
> {
> + pm_runtime_disable(csi_dev->dev);
> clk_rate_exclusive_put(csi_dev->clk_mod);
> }
>
> @@ -978,6 +1021,7 @@ static struct platform_driver sun6i_csi_platform_driver
= {
> .driver = {
> .name = SUN6I_CSI_NAME,
> .of_match_table =
of_match_ptr(sun6i_csi_of_match),
> + .pm = &sun6i_csi_pm_ops,
> },
> };
>
> --
> 2.35.1
>
>