Re: [PATCH v5 15/20] memory: mtk-smi: Invoke pm runtime_callback to enable clocks

Evan Green
2019-01-30T19:05:03Z

On Mon, Dec 31, 2018 at 7:59 PM Yong Wu <yong.wu@mediatek.com> wrote:
>
> This patch only move the clk_prepare_enable and config_port into the
> runtime suspend/resume callback. It doesn't change the code content
> and sequence.
>
> This is a preparing patch for adjusting SMI_BUS_SEL for mt8183.
> (SMI_BUS_SEL need to be restored after smi-common resume every time.)
> Also it gives a chance to get rid of mtk_smi_larb_get/put which could
> be a next topic.
>
> CC: Matthias Brugger <matthias.bgg@gmail.com>
> Signed-off-by: Yong Wu <yong.wu@mediatek.com>

I believe this refactoring is a no-op as described, because the order is still:
1) mtk_smi_clk_enable(common)
2) mtk_smi_clk_enable(larb)
3) larb_gen->config_port()

And teardown still happens in the opposite order, except for
config_port, which they seem not to do in suspend.
So, looks good to me.

Reviewed-by: Evan Green <evgreen@chromium.org>

> ---
> drivers/memory/mtk-smi.c | 113 ++++++++++++++++++++++++++++++-----------------
> 1 file changed, 72 insertions(+), 41 deletions(-)
>
> diff --git a/drivers/memory/mtk-smi.c b/drivers/memory/mtk-smi.c
> index a430721..9790801 100644
> --- a/drivers/memory/mtk-smi.c
> +++ b/drivers/memory/mtk-smi.c
> @@ -86,17 +86,13 @@ struct mtk_smi_larb { /* larb: local arbiter */
> u32 *mmu;
> };
>
> -static int mtk_smi_enable(const struct mtk_smi *smi)
> +static int mtk_smi_clk_enable(const struct mtk_smi *smi)
> {
> int ret;
>
> - ret = pm_runtime_get_sync(smi->dev);
> - if (ret < 0)
> - return ret;
> -
> ret = clk_prepare_enable(smi->clk_apb);
> if (ret)
> - goto err_put_pm;
> + return ret;
>
> ret = clk_prepare_enable(smi->clk_smi);
> if (ret)
> @@ -118,59 +114,28 @@ static int mtk_smi_enable(const struct mtk_smi *smi)
> clk_disable_unprepare(smi->clk_smi);
> err_disable_apb:
> clk_disable_unprepare(smi->clk_apb);
> -err_put_pm:
> - pm_runtime_put_sync(smi->dev);
> return ret;
> }
>
> -static void mtk_smi_disable(const struct mtk_smi *smi)
> +static void mtk_smi_clk_disable(const struct mtk_smi *smi)
> {
> clk_disable_unprepare(smi->clk_gals1);
> clk_disable_unprepare(smi->clk_gals0);
> clk_disable_unprepare(smi->clk_smi);
> clk_disable_unprepare(smi->clk_apb);
> - pm_runtime_put_sync(smi->dev);
> }
>
> int mtk_smi_larb_get(struct device *larbdev)
> {
> - struct mtk_smi_larb *larb = dev_get_drvdata(larbdev);
> - const struct mtk_smi_larb_gen *larb_gen = larb->larb_gen;
> - struct mtk_smi *common = dev_get_drvdata(larb->smi_common_dev);
> - int ret;
> + int ret = pm_runtime_get_sync(larbdev);
>
> - /* Enable the smi-common's power and clocks */
> - ret = mtk_smi_enable(common);
> - if (ret)
> - return ret;
> -
> - /* Enable the larb's power and clocks */
> - ret = mtk_smi_enable(&larb->smi);
> - if (ret) {
> - mtk_smi_disable(common);
> - return ret;
> - }
> -
> - /* Configure the iommu info for this larb */
> - larb_gen->config_port(larbdev);
> -
> - return 0;
> + return (ret < 0) ? ret : 0;
> }
> EXPORT_SYMBOL_GPL(mtk_smi_larb_get);
>
> void mtk_smi_larb_put(struct device *larbdev)
> {
> - struct mtk_smi_larb *larb = dev_get_drvdata(larbdev);
> - struct mtk_smi *common = dev_get_drvdata(larb->smi_common_dev);
> -
> - /*
> - * Don't de-configure the iommu info for this larb since there may be
> - * several modules in this larb.
> - * The iommu info will be reset after power off.
> - */
> -
> - mtk_smi_disable(&larb->smi);
> - mtk_smi_disable(common);
> + pm_runtime_put_sync(larbdev);
> }
> EXPORT_SYMBOL_GPL(mtk_smi_larb_put);
>
> @@ -385,12 +350,52 @@ static int mtk_smi_larb_remove(struct platform_device *pdev)
> return 0;
> }
>
> +static int __maybe_unused mtk_smi_larb_resume(struct device *dev)
> +{
> + struct mtk_smi_larb *larb = dev_get_drvdata(dev);
> + const struct mtk_smi_larb_gen *larb_gen = larb->larb_gen;
> + int ret;
> +
> + /* Power on smi-common. */
> + ret = pm_runtime_get_sync(larb->smi_common_dev);
> + if (ret < 0) {
> + dev_err(dev, "Failed to pm get for smi-common(%d).\n", ret);
> + return ret;
> + }
> +
> + ret = mtk_smi_clk_enable(&larb->smi);
> + if (ret < 0) {
> + dev_err(dev, "Failed to enable clock(%d).\n", ret);
> + pm_runtime_put_sync(larb->smi_common_dev);
> + return ret;
> + }
> +
> + /* Configure the basic setting for this larb */
> + larb_gen->config_port(dev);
> +
> + return 0;
> +}
> +
> +static int __maybe_unused mtk_smi_larb_suspend(struct device *dev)
> +{
> + struct mtk_smi_larb *larb = dev_get_drvdata(dev);
> +
> + mtk_smi_clk_disable(&larb->smi);
> + pm_runtime_put_sync(larb->smi_common_dev);
> + return 0;
> +}
> +
> +static const struct dev_pm_ops smi_larb_pm_ops = {
> + SET_RUNTIME_PM_OPS(mtk_smi_larb_suspend, mtk_smi_larb_resume, NULL)
> +};
> +
> static struct platform_driver mtk_smi_larb_driver = {
> .probe = mtk_smi_larb_probe,
> .remove = mtk_smi_larb_remove,
> .driver = {
> .name = "mtk-smi-larb",
> .of_match_table = mtk_smi_larb_of_ids,
> + .pm = &smi_larb_pm_ops,
> }
> };
>
> @@ -489,12 +494,38 @@ static int mtk_smi_common_remove(struct platform_device *pdev)
> return 0;
> }
>
> +static int __maybe_unused mtk_smi_common_resume(struct device *dev)
> +{
> + struct mtk_smi *common = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = mtk_smi_clk_enable(common);
> + if (ret) {
> + dev_err(common->dev, "Failed to enable clock(%d).\n", ret);
> + return ret;
> + }
> + return 0;
> +}
> +
> +static int __maybe_unused mtk_smi_common_suspend(struct device *dev)
> +{
> + struct mtk_smi *common = dev_get_drvdata(dev);
> +
> + mtk_smi_clk_disable(common);
> + return 0;
> +}
> +
> +static const struct dev_pm_ops smi_common_pm_ops = {
> + SET_RUNTIME_PM_OPS(mtk_smi_common_suspend, mtk_smi_common_resume, NULL)
> +};
> +
> static struct platform_driver mtk_smi_common_driver = {
> .probe = mtk_smi_common_probe,
> .remove = mtk_smi_common_remove,
> .driver = {
> .name = "mtk-smi-common",
> .of_match_table = mtk_smi_common_of_ids,
> + .pm = &smi_common_pm_ops,
> }
> };
>
> --
> 1.9.1
>