2022-09-18 10:01:24

by Martin Povišer

Subject: [PATCH 4/4] dmaengine: apple-admac: Trigger shared reset

If a reset domain is attached to the device, obtain a shared reference
to it and trigger it. Typically on a chip the ADMAC controller will
share a reset domain with the MCA peripheral.

Signed-off-by: Martin Povišer <[email protected]>
---
drivers/dma/apple-admac.c | 22 +++++++++++++++++++---
1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/apple-admac.c b/drivers/dma/apple-admac.c
index 7d1b76678032..317ca76ccafd 100644
--- a/drivers/dma/apple-admac.c
+++ b/drivers/dma/apple-admac.c
@@ -12,8 +12,9 @@
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/of_dma.h>
-#include <linux/interrupt.h>
+#include <linux/reset.h>
#include <linux/spinlock.h>
+#include <linux/interrupt.h>

#include "dmaengine.h"

@@ -95,6 +96,7 @@ struct admac_data {
struct dma_device dma;
struct device *dev;
__iomem void *base;
+ struct reset_control *rstc;

int irq;
int irq_index;
@@ -732,6 +734,10 @@ static int admac_probe(struct platform_device *pdev)
return dev_err_probe(&pdev->dev, PTR_ERR(ad->base),
"unable to obtain MMIO resource\n");

+ ad->rstc = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
+ if (IS_ERR(ad->rstc))
+ return PTR_ERR(ad->rstc);
+
dma = &ad->dma;

dma_cap_set(DMA_PRIVATE, dma->cap_mask);
@@ -770,10 +776,17 @@ static int admac_probe(struct platform_device *pdev)
tasklet_setup(&adchan->tasklet, admac_chan_tasklet);
}

- err = request_irq(irq, admac_interrupt, 0, dev_name(&pdev->dev), ad);
+ err = reset_control_reset(ad->rstc);
if (err)
return dev_err_probe(&pdev->dev, err,
- "unable to register interrupt\n");
+ "unable to trigger reset\n");
+
+ err = request_irq(irq, admac_interrupt, 0, dev_name(&pdev->dev), ad);
+ if (err) {
+ dev_err_probe(&pdev->dev, err,
+ "unable to register interrupt\n");
+ goto free_reset;
+ }

err = dma_async_device_register(&ad->dma);
if (err) {
@@ -792,6 +805,8 @@ static int admac_probe(struct platform_device *pdev)

free_irq:
free_irq(ad->irq, ad);
+free_reset:
+ reset_control_rearm(ad->rstc);
return err;
}

@@ -802,6 +817,7 @@ static int admac_remove(struct platform_device *pdev)
of_dma_controller_free(pdev->dev.of_node);
dma_async_device_unregister(&ad->dma);
free_irq(ad->irq, ad);
+ reset_control_rearm(ad->rstc);

return 0;
}
--
2.33.0

2022-09-30 09:31:46

by Philipp Zabel

Subject: Re: [PATCH 4/4] dmaengine: apple-admac: Trigger shared reset

Hi Martin,

On So, 2022-09-18 at 11:58 +0200, Martin Povišer wrote:
> If a reset domain is attached to the device, obtain a shared reference
> to it and trigger it. Typically on a chip the ADMAC controller will
> share a reset domain with the MCA peripheral.
>
> Signed-off-by: Martin Povišer <[email protected]>
> ---
>  drivers/dma/apple-admac.c | 22 +++++++++++++++++++---
>  1 file changed, 19 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/dma/apple-admac.c b/drivers/dma/apple-admac.c
> index 7d1b76678032..317ca76ccafd 100644
> --- a/drivers/dma/apple-admac.c
> +++ b/drivers/dma/apple-admac.c
> @@ -12,8 +12,9 @@
>  #include <linux/module.h>
>  #include <linux/of_device.h>
>  #include <linux/of_dma.h>
> -#include <linux/interrupt.h>
> +#include <linux/reset.h>
>  #include <linux/spinlock.h>
> +#include <linux/interrupt.h>

Moving around the linux/interrupt.h include doesn't belong in this
patch. Otherwise this looks good to me, assuming the MCA driver does
the same reset/rearm dance.

regards
Philipp