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

Yong Wu
2019-01-31T03:42:55Z

On Wed, 2019-01-30 at 11:05 -0800, Evan Green wrote:
> 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

Thanks your confirm.

> config_port, which they seem not to do in suspend.

After suspend, the HW engine should not work. config_port is not
helpful. At that time, use the HW default value.

> So, looks good to me.
>
> Reviewed-by: Evan Green <evgreen@chromium.org>

Thanks.

>
> > ---
> > 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
> >