[RFC PATCH 02/10] dma-engine: sun4i: Add has_reset option to quirk

From: Mesih Kilinc
Date: Sun Dec 02 2018 - 16:23:40 EST


Allwinner suniv F1C100s has a reset bit for DMA in CCU. Sun4i do not
has this bit but in order to support suniv we need to add it. So add
support for reset bit.

Signed-off-by: Mesih Kilinc <mesihkilinc@xxxxxxxxx>
---
drivers/dma/sun4i-dma.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)

diff --git a/drivers/dma/sun4i-dma.c b/drivers/dma/sun4i-dma.c
index e86b424..d267ff9 100644
--- a/drivers/dma/sun4i-dma.c
+++ b/drivers/dma/sun4i-dma.c
@@ -18,6 +18,7 @@
#include <linux/of_dma.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
+#include <linux/reset.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

@@ -153,6 +154,7 @@ struct sun4i_dma_config {
u8 ddma_drq_sdram;

u8 max_burst;
+ bool has_reset;
};

struct sun4i_dma_pchan {
@@ -201,6 +203,7 @@ struct sun4i_dma_dev {
int irq;
spinlock_t lock;
const struct sun4i_dma_config *cfg;
+ struct reset_control *rst;
};

static struct sun4i_dma_dev *to_sun4i_dma_dev(struct dma_device *dev)
@@ -1198,6 +1201,15 @@ static int sun4i_dma_probe(struct platform_device *pdev)
return PTR_ERR(priv->clk);
}

+ if(priv->cfg->has_reset) {
+ priv->rst = devm_reset_control_get_exclusive(&pdev->dev,
+ NULL);
+ if (IS_ERR(priv->rst)) {
+ dev_err(&pdev->dev, "Failed to get reset control\n");
+ return PTR_ERR(priv->rst);
+ }
+ }
+
platform_set_drvdata(pdev, priv);
spin_lock_init(&priv->lock);

@@ -1268,6 +1280,16 @@ static int sun4i_dma_probe(struct platform_device *pdev)
return ret;
}

+ /* Deassert the reset control */
+ if (priv->rst) {
+ ret = reset_control_deassert(priv->rst);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "Failed to deassert the reset control\n");
+ goto err_clk_disable;
+ }
+ }
+
/*
* Make sure the IRQs are all disabled and accounted for. The bootloader
* likes to leave these dirty
@@ -1339,6 +1361,7 @@ static struct sun4i_dma_config sun4i_a10_dma_cfg = {
.ddma_drq_sdram = SUN4I_DDMA_DRQ_TYPE_SDRAM,

.max_burst = SUN4I_MAX_BURST,
+ .has_reset = false,
};

static const struct of_device_id sun4i_dma_match[] = {
--
2.7.4