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 <povik+lin@cutebit.org>
Link: https://lore.kernel.org/r/20220918095845.68860-5-povik+lin@cutebit.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/apple-admac.c b/drivers/dma/apple-admac.c
index 7d1b766..317ca76 100644 (file)
--- 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;
 }