[PATCH v2] dmaengine: sh: rz-dmac: Add DMA clock handling

[PATCH v2] dmaengine: sh: rz-dmac: Add DMA clock handling

[Biju Das]

Currently, DMA clocks are turned on by the bootloader.
This patch adds support for DMA clock handling so that
the driver manages the DMA clocks.

Fixes: 5000d37042a6 ("dmaengine: sh: Add DMAC driver for RZ/G2L SoC")
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
v1->v2:
 * Handled the failure case for pm_runtime_resume_and_get
 * Added Geert's Rb tag.
---
 drivers/dma/sh/rz-dmac.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/dma/sh/rz-dmac.c b/drivers/dma/sh/rz-dmac.c
index f9f30cbeccbe..d9f2cfef878e 100644
--- a/drivers/dma/sh/rz-dmac.c
+++ b/drivers/dma/sh/rz-dmac.c
@@ -18,6 +18,7 @@
 #include <linux/of_dma.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 
@@ -872,6 +873,13 @@ static int rz_dmac_probe(struct platform_device *pdev)
 	/* Initialize the channels. */
 	INIT_LIST_HEAD(&dmac->engine.channels);
 
+	pm_runtime_enable(&pdev->dev);
+	ret = pm_runtime_resume_and_get(&pdev->dev);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "pm_runtime_resume_and_get failed\n");
+		goto err_pm_disable;
+	}
+
 	for (i = 0; i < dmac->n_channels; i++) {
 		ret = rz_dmac_chan_probe(dmac, &dmac->channels[i], i);
 		if (ret < 0)
@@ -925,6 +933,10 @@ static int rz_dmac_probe(struct platform_device *pdev)
 				  channel->lmdesc.base_dma);
 	}
 
+	pm_runtime_put(&pdev->dev);
+err_pm_disable:
+	pm_runtime_disable(&pdev->dev);
+
 	return ret;
 }
 
@@ -943,6 +955,8 @@ static int rz_dmac_remove(struct platform_device *pdev)
 	}
 	of_dma_controller_free(pdev->dev.of_node);
 	dma_async_device_unregister(&dmac->engine);
+	pm_runtime_put(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
 
 	return 0;
 }
-- 
2.17.1

Re: [PATCH v2] dmaengine: sh: rz-dmac: Add DMA clock handling

[Geert Uytterhoeven]

Hi Biju, Vinod,

On Thu, Sep 23, 2021 at 12:25 PM Biju Das <biju.das.jz@bp.renesas.com> wrote:
> Currently, DMA clocks are turned on by the bootloader.
> This patch adds support for DMA clock handling so that
> the driver manages the DMA clocks.
>
> Fixes: 5000d37042a6 ("dmaengine: sh: Add DMAC driver for RZ/G2L SoC")
> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

If I'm not mistaken, this is a fix we want in v5.15, to avoid
regressions when the clock driver will be fixed (in clk-fixes for
v5.15), and DMA will be enabled in DT (in v5.16)?

Thanks!

> ---
> v1->v2:
>  * Handled the failure case for pm_runtime_resume_and_get
>  * Added Geert's Rb tag.
> ---
>  drivers/dma/sh/rz-dmac.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
>
> diff --git a/drivers/dma/sh/rz-dmac.c b/drivers/dma/sh/rz-dmac.c
> index f9f30cbeccbe..d9f2cfef878e 100644
> --- a/drivers/dma/sh/rz-dmac.c
> +++ b/drivers/dma/sh/rz-dmac.c
> @@ -18,6 +18,7 @@
>  #include <linux/of_dma.h>
>  #include <linux/of_platform.h>
>  #include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/slab.h>
>  #include <linux/spinlock.h>
>
> @@ -872,6 +873,13 @@ static int rz_dmac_probe(struct platform_device *pdev)
>         /* Initialize the channels. */
>         INIT_LIST_HEAD(&dmac->engine.channels);
>
> +       pm_runtime_enable(&pdev->dev);
> +       ret = pm_runtime_resume_and_get(&pdev->dev);
> +       if (ret < 0) {
> +               dev_err(&pdev->dev, "pm_runtime_resume_and_get failed\n");
> +               goto err_pm_disable;
> +       }
> +
>         for (i = 0; i < dmac->n_channels; i++) {
>                 ret = rz_dmac_chan_probe(dmac, &dmac->channels[i], i);
>                 if (ret < 0)
> @@ -925,6 +933,10 @@ static int rz_dmac_probe(struct platform_device *pdev)
>                                   channel->lmdesc.base_dma);
>         }
>
> +       pm_runtime_put(&pdev->dev);
> +err_pm_disable:
> +       pm_runtime_disable(&pdev->dev);
> +
>         return ret;
>  }
>
> @@ -943,6 +955,8 @@ static int rz_dmac_remove(struct platform_device *pdev)
>         }
>         of_dma_controller_free(pdev->dev.of_node);
>         dma_async_device_unregister(&dmac->engine);
> +       pm_runtime_put(&pdev->dev);
> +       pm_runtime_disable(&pdev->dev);
>
>         return 0;
>  }

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

RE: [PATCH v2] dmaengine: sh: rz-dmac: Add DMA clock handling

[Biju Das]

Hi Geert,

Thanks for the feedback.

> Subject: Re: [PATCH v2] dmaengine: sh: rz-dmac: Add DMA clock handling
> 
> Hi Biju, Vinod,
> 
> On Thu, Sep 23, 2021 at 12:25 PM Biju Das <biju.das.jz@bp.renesas.com>
> wrote:
> > Currently, DMA clocks are turned on by the bootloader.
> > This patch adds support for DMA clock handling so that the driver
> > manages the DMA clocks.
> >
> > Fixes: 5000d37042a6 ("dmaengine: sh: Add DMAC driver for RZ/G2L SoC")
> > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> > Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
> 
> If I'm not mistaken, this is a fix we want in v5.15, to avoid regressions
> when the clock driver will be fixed (in clk-fixes for v5.15), and DMA will
> be enabled in DT (in v5.16)?

Yes that is correct, otherwise it will cause regression.
Vinod, can you please apply this as fixes in 5.15.

Regards,
Biju

> 
> Thanks!
> 
> > ---
> > v1->v2:
> >  * Handled the failure case for pm_runtime_resume_and_get
> >  * Added Geert's Rb tag.
> > ---
> >  drivers/dma/sh/rz-dmac.c | 14 ++++++++++++++
> >  1 file changed, 14 insertions(+)
> >
> > diff --git a/drivers/dma/sh/rz-dmac.c b/drivers/dma/sh/rz-dmac.c index
> > f9f30cbeccbe..d9f2cfef878e 100644
> > --- a/drivers/dma/sh/rz-dmac.c
> > +++ b/drivers/dma/sh/rz-dmac.c
> > @@ -18,6 +18,7 @@
> >  #include <linux/of_dma.h>
> >  #include <linux/of_platform.h>
> >  #include <linux/platform_device.h>
> > +#include <linux/pm_runtime.h>
> >  #include <linux/slab.h>
> >  #include <linux/spinlock.h>
> >
> > @@ -872,6 +873,13 @@ static int rz_dmac_probe(struct platform_device
> *pdev)
> >         /* Initialize the channels. */
> >         INIT_LIST_HEAD(&dmac->engine.channels);
> >
> > +       pm_runtime_enable(&pdev->dev);
> > +       ret = pm_runtime_resume_and_get(&pdev->dev);
> > +       if (ret < 0) {
> > +               dev_err(&pdev->dev, "pm_runtime_resume_and_get
> failed\n");
> > +               goto err_pm_disable;
> > +       }
> > +
> >         for (i = 0; i < dmac->n_channels; i++) {
> >                 ret = rz_dmac_chan_probe(dmac, &dmac->channels[i], i);
> >                 if (ret < 0)
> > @@ -925,6 +933,10 @@ static int rz_dmac_probe(struct platform_device
> *pdev)
> >                                   channel->lmdesc.base_dma);
> >         }
> >
> > +       pm_runtime_put(&pdev->dev);
> > +err_pm_disable:
> > +       pm_runtime_disable(&pdev->dev);
> > +
> >         return ret;
> >  }
> >
> > @@ -943,6 +955,8 @@ static int rz_dmac_remove(struct platform_device
> *pdev)
> >         }
> >         of_dma_controller_free(pdev->dev.of_node);
> >         dma_async_device_unregister(&dmac->engine);
> > +       pm_runtime_put(&pdev->dev);
> > +       pm_runtime_disable(&pdev->dev);
> >
> >         return 0;
> >  }
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-
> m68k.org
> 
> In personal conversations with technical people, I call myself a hacker.
> But when I'm talking to journalists I just say "programmer" or something
> like that.
>                                 -- Linus Torvalds

Re: [PATCH v2] dmaengine: sh: rz-dmac: Add DMA clock handling

[Vinod Koul]

On 23-09-21, 11:24, Biju Das wrote:
> Currently, DMA clocks are turned on by the bootloader.
> This patch adds support for DMA clock handling so that
> the driver manages the DMA clocks.

Applied, thanks

-- 
~Vinod