diff mbox series

[v5,2/5] dma-engine: sun4i: Add has_reset option to quirk

Message ID 20241102093140.2625230-3-csokas.bence@prolan.hu (mailing list archive)
State Changes Requested
Headers show
Series [v5,1/5] dma-engine: sun4i: Add a quirk to support different chips | expand

Commit Message

Bence Csókás Nov. 2, 2024, 9:31 a.m. UTC
From: Mesih Kilinc <mesihkilinc@gmail.com>

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@gmail.com>
[ csokas.bence: Rebased and addressed comments ]
Signed-off-by: Csókás, Bence <csokas.bence@prolan.hu>
---

Notes:
    Changes in v2:
    * Call reset_control_deassert() unconditionally, as it supports optional resets
    * Use dev_err_probe()
    * Whitespace
    Changes in v3:
    * More dev_err_probe() fixes
    Changes in v4:
    * Use return value of dev_err_probe()
    Changes in v5:
    * More whitespace

 drivers/dma/sun4i-dma.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

Comments

Andre Przywara Nov. 2, 2024, 5:45 p.m. UTC | #1
On Sat, 2 Nov 2024 10:31:41 +0100
"Csókás, Bence" <csokas.bence@prolan.hu> wrote:

Hi,

> From: Mesih Kilinc <mesihkilinc@gmail.com>
> 
> 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@gmail.com>
> [ csokas.bence: Rebased and addressed comments ]
> Signed-off-by: Csókás, Bence <csokas.bence@prolan.hu>
> ---
> 
> Notes:
>     Changes in v2:
>     * Call reset_control_deassert() unconditionally, as it supports optional resets
>     * Use dev_err_probe()
>     * Whitespace
>     Changes in v3:
>     * More dev_err_probe() fixes
>     Changes in v4:
>     * Use return value of dev_err_probe()
>     Changes in v5:
>     * More whitespace
> 
>  drivers/dma/sun4i-dma.c | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/drivers/dma/sun4i-dma.c b/drivers/dma/sun4i-dma.c
> index b2c1e4b9f696..9d1e3c51342d 100644
> --- a/drivers/dma/sun4i-dma.c
> +++ b/drivers/dma/sun4i-dma.c
> @@ -15,6 +15,7 @@
>  #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>
>  
> @@ -159,6 +160,7 @@ struct sun4i_dma_config {
>  	u8 ddma_drq_sdram;
>  
>  	u8 max_burst;
> +	bool has_reset;
>  };
>  
>  struct sun4i_dma_pchan {
> @@ -208,6 +210,7 @@ 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)
> @@ -1215,6 +1218,13 @@ 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);

Can't we use devm_reset_control_get_optional_exclusive(), and then save
this whole has_reset bit?

> +		if (IS_ERR(priv->rst))
> +			return dev_err_probe(&pdev->dev, PTR_ERR(priv->rst),
> +					     "Failed to get reset control\n");
> +	}
> +
>  	platform_set_drvdata(pdev, priv);
>  	spin_lock_init(&priv->lock);
>  
> @@ -1287,6 +1297,14 @@ static int sun4i_dma_probe(struct platform_device *pdev)
>  		return ret;
>  	}
>  
> +	/* Deassert the reset control */
> +	ret = reset_control_deassert(priv->rst);
> +	if (ret) {
> +		dev_err_probe(&pdev->dev, ret,
> +			      "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
> @@ -1355,6 +1373,7 @@ 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[] = {
Bence Csókás Nov. 4, 2024, 7:41 a.m. UTC | #2
Hi!

On 2024. 11. 02. 18:45, Andre Przywara wrote:
> On Sat, 2 Nov 2024 10:31:41 +0100
> "Csókás, Bence" <csokas.bence@prolan.hu> wrote:
> 
> Hi,
> 
>> From: Mesih Kilinc <mesihkilinc@gmail.com>
>>
>>   static struct sun4i_dma_dev *to_sun4i_dma_dev(struct dma_device *dev)
>> @@ -1215,6 +1218,13 @@ 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);
> 
> Can't we use devm_reset_control_get_optional_exclusive(), and then save
> this whole has_reset bit?

For suniv, reset is REQUIRED. For sun4i, reset DOES NOT EXIST.

has_reset does not mean that whether this instance has a reset control 
or not, that is handled by checking priv->rst for NULL. has_reset means 
whether reset is REQUIRED by this type of DMA, specified by the DT match 
data.

Bence
diff mbox series

Patch

diff --git a/drivers/dma/sun4i-dma.c b/drivers/dma/sun4i-dma.c
index b2c1e4b9f696..9d1e3c51342d 100644
--- a/drivers/dma/sun4i-dma.c
+++ b/drivers/dma/sun4i-dma.c
@@ -15,6 +15,7 @@ 
 #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>
 
@@ -159,6 +160,7 @@  struct sun4i_dma_config {
 	u8 ddma_drq_sdram;
 
 	u8 max_burst;
+	bool has_reset;
 };
 
 struct sun4i_dma_pchan {
@@ -208,6 +210,7 @@  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)
@@ -1215,6 +1218,13 @@  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))
+			return dev_err_probe(&pdev->dev, PTR_ERR(priv->rst),
+					     "Failed to get reset control\n");
+	}
+
 	platform_set_drvdata(pdev, priv);
 	spin_lock_init(&priv->lock);
 
@@ -1287,6 +1297,14 @@  static int sun4i_dma_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	/* Deassert the reset control */
+	ret = reset_control_deassert(priv->rst);
+	if (ret) {
+		dev_err_probe(&pdev->dev, ret,
+			      "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
@@ -1355,6 +1373,7 @@  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[] = {