Alexandre Bailon <abailon@xxxxxxxxxxxx> writes:
> Currently, MUSB DA8xx glue driver doesn't have PM runtime support.
> Because the CPPI 4.1 is using the same clock as MUSB DA8xx and
> CPPI 4.1 is a child of MUSB DA8xx glue, add support of PM runtime
> to the DA8xx glue driver in order to let the CPPI 4.1 driver manage
> the clock by using PM runtime.
>
> Signed-off-by: Alexandre Bailon <abailon@xxxxxxxxxxxx>
Dumb question: even if the clock is shared with cppi4, doesn't the
use-couting in the clock API handle it so that things should function
fine even without this patch?
Some other comments/questions below...
> ---
> drivers/usb/musb/da8xx.c | 27 ++++++++-------------------
> 1 file changed, 8 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/usb/musb/da8xx.c b/drivers/usb/musb/da8xx.c
> index ed28afd..89e12f6 100644
> --- a/drivers/usb/musb/da8xx.c
> +++ b/drivers/usb/musb/da8xx.c
> @@ -30,7 +30,6 @@
> */
>
> #include <linux/module.h>
> -#include <linux/clk.h>
> #include <linux/err.h>
> #include <linux/io.h>
> #include <linux/of_platform.h>
> @@ -86,7 +85,6 @@ struct da8xx_glue {
> struct device *dev;
> struct platform_device *musb;
> struct platform_device *usb_phy;
> - struct clk *clk;
> struct phy *phy;
> };
>
> @@ -376,11 +374,7 @@ static int da8xx_musb_init(struct musb *musb)
>
> musb->mregs += DA8XX_MENTOR_CORE_OFFSET;
>
> - ret = clk_prepare_enable(glue->clk);
> - if (ret) {
> - dev_err(glue->dev, "failed to enable clock\n");
> - return ret;
> - }
> + pm_runtime_get_sync(musb->controller->parent);
>
> /* Returns zero if e.g. not clocked */
> rev = musb_readl(reg_base, DA8XX_USB_REVISION_REG);
> @@ -423,7 +417,7 @@ static int da8xx_musb_init(struct musb *musb)
> err_phy_power_on:
> phy_exit(glue->phy);
> fail:
> - clk_disable_unprepare(glue->clk);
> + pm_runtime_put(musb->controller->parent);
> return ret;
> }
>
> @@ -435,7 +429,7 @@ static int da8xx_musb_exit(struct musb *musb)
>
> phy_power_off(glue->phy);
> phy_exit(glue->phy);
> - clk_disable_unprepare(glue->clk);
> + pm_runtime_put(musb->controller->parent);
>
> usb_put_phy(musb->xceiv);
>
> @@ -519,7 +513,6 @@ static int da8xx_probe(struct platform_device *pdev)
> struct musb_hdrc_platform_data *pdata = dev_get_platdata(&pdev->dev);
> struct da8xx_glue *glue;
> struct platform_device_info pinfo;
> - struct clk *clk;
> struct device_node *np = pdev->dev.of_node;
> int ret;
>
> @@ -527,12 +520,6 @@ static int da8xx_probe(struct platform_device *pdev)
> if (!glue)
> return -ENOMEM;
>
> - clk = devm_clk_get(&pdev->dev, "usb20");
> - if (IS_ERR(clk)) {
> - dev_err(&pdev->dev, "failed to get clock\n");
> - return PTR_ERR(clk);
> - }
Something isn't quite right here.
This clk_get uses a con_id "usb20", but when converting to runtime PM,
we rely on the pm_clk layer (used on davinci for runtime PM) to do clock
lookups by the default con_ids. I guess this still probably works
because we fallback to the NULL con_id.
> glue->phy = devm_phy_get(&pdev->dev, "usb-phy");
> if (IS_ERR(glue->phy)) {
> if (PTR_ERR(glue->phy) != -EPROBE_DEFER)
> @@ -541,7 +528,6 @@ static int da8xx_probe(struct platform_device *pdev)
> }
>
> glue->dev = &pdev->dev;
> - glue->clk = clk;
>
> if (IS_ENABLED(CONFIG_OF) && np) {
> pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
> @@ -587,6 +573,8 @@ static int da8xx_probe(struct platform_device *pdev)
> pinfo.data = pdata;
> pinfo.size_data = sizeof(*pdata);
>
> + pm_runtime_enable(&pdev->dev);
> +
> glue->musb = platform_device_register_full(&pinfo);
> ret = PTR_ERR_OR_ZERO(glue->musb);
> if (ret) {
> @@ -603,6 +591,7 @@ static int da8xx_remove(struct platform_device *pdev)
>
> platform_device_unregister(glue->musb);
> usb_phy_generic_unregister(glue->usb_phy);
> + pm_runtime_disable(&pdev->dev);
>
> return 0;
> }
> @@ -616,7 +605,7 @@ static int da8xx_suspend(struct device *dev)
> ret = phy_power_off(glue->phy);
> if (ret)
> return ret;
> - clk_disable_unprepare(glue->clk);
> + pm_runtime_put_sync(dev);
I'm a bit lots in the MUSB layering here, but does this 'dev' correspond
to musb->controller->parent?
Kevin
> return 0;
> }
> @@ -626,7 +615,7 @@ static int da8xx_resume(struct device *dev)
> int ret;
> struct da8xx_glue *glue = dev_get_drvdata(dev);
>
> - ret = clk_prepare_enable(glue->clk);
> + ret = pm_runtime_get_sync(dev);
> if (ret)
> return ret;
> return phy_power_on(glue->phy);
--
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