On Sat, 2 Nov 2024 10:31:41 +0100
"Csókás, Bence" <csokas.bence@xxxxxxxxx> wrote:
Hi,
> From: Mesih Kilinc <mesihkilinc@xxxxxxxxx>
>
> 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>
> [ csokas.bence: Rebased and addressed comments ]
> Signed-off-by: Csókás, Bence <csokas.bence@xxxxxxxxx>
> ---
>
> 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[] = {
