Re: [PATCH v12 03/12] dmaengine: qcom: bam_dma: Extend the driver's device match data

[Manivannan Sadhasivam]

On Tue, Mar 10, 2026 at 04:44:17PM +0100, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> 
> In preparation for supporting the pipe locking feature flag, extend the
> amount of information we can carry in device match data: create a
> separate structure and make the register information one of its fields.
> This way, in subsequent patches, it will be just a matter of adding a
> new field to the device data.
> 

Nit: s/patches/commits

> Reviewed-by: Dmitry Baryshkov <lumag@xxxxxxxxxx>
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxxxxxxxx>

Reviewed-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>

- Mani

> ---
>  drivers/dma/qcom/bam_dma.c | 28 ++++++++++++++++++++++------
>  1 file changed, 22 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c
> index c8601bac555edf1bb4384fd39cb3449ec6e86334..8f6d03f6c673b57ed13aeca6c8331c71596d077b 100644
> --- a/drivers/dma/qcom/bam_dma.c
> +++ b/drivers/dma/qcom/bam_dma.c
> @@ -113,6 +113,10 @@ struct reg_offset_data {
>  	unsigned int pipe_mult, evnt_mult, ee_mult;
>  };
>  
> +struct bam_device_data {
> +	const struct reg_offset_data *reg_info;
> +};
> +
>  static const struct reg_offset_data bam_v1_3_reg_info[] = {
>  	[BAM_CTRL]		= { 0x0F80, 0x00, 0x00, 0x00 },
>  	[BAM_REVISION]		= { 0x0F84, 0x00, 0x00, 0x00 },
> @@ -142,6 +146,10 @@ static const struct reg_offset_data bam_v1_3_reg_info[] = {
>  	[BAM_P_FIFO_SIZES]	= { 0x1020, 0x00, 0x40, 0x00 },
>  };
>  
> +static const struct bam_device_data bam_v1_3_data = {
> +	.reg_info = bam_v1_3_reg_info,
> +};
> +
>  static const struct reg_offset_data bam_v1_4_reg_info[] = {
>  	[BAM_CTRL]		= { 0x0000, 0x00, 0x00, 0x00 },
>  	[BAM_REVISION]		= { 0x0004, 0x00, 0x00, 0x00 },
> @@ -171,6 +179,10 @@ static const struct reg_offset_data bam_v1_4_reg_info[] = {
>  	[BAM_P_FIFO_SIZES]	= { 0x1820, 0x00, 0x1000, 0x00 },
>  };
>  
> +static const struct bam_device_data bam_v1_4_data = {
> +	.reg_info = bam_v1_4_reg_info,
> +};
> +
>  static const struct reg_offset_data bam_v1_7_reg_info[] = {
>  	[BAM_CTRL]		= { 0x00000, 0x00, 0x00, 0x00 },
>  	[BAM_REVISION]		= { 0x01000, 0x00, 0x00, 0x00 },
> @@ -200,6 +212,10 @@ static const struct reg_offset_data bam_v1_7_reg_info[] = {
>  	[BAM_P_FIFO_SIZES]	= { 0x13820, 0x00, 0x1000, 0x00 },
>  };
>  
> +static const struct bam_device_data bam_v1_7_data = {
> +	.reg_info = bam_v1_7_reg_info,
> +};
> +
>  /* BAM CTRL */
>  #define BAM_SW_RST			BIT(0)
>  #define BAM_EN				BIT(1)
> @@ -393,7 +409,7 @@ struct bam_device {
>  	bool powered_remotely;
>  	u32 active_channels;
>  
> -	const struct reg_offset_data *layout;
> +	const struct bam_device_data *dev_data;
>  
>  	struct clk *bamclk;
>  	int irq;
> @@ -411,7 +427,7 @@ struct bam_device {
>  static inline void __iomem *bam_addr(struct bam_device *bdev, u32 pipe,
>  		enum bam_reg reg)
>  {
> -	const struct reg_offset_data r = bdev->layout[reg];
> +	const struct reg_offset_data r = bdev->dev_data->reg_info[reg];
>  
>  	return bdev->regs + r.base_offset +
>  		r.pipe_mult * pipe +
> @@ -1205,9 +1221,9 @@ static void bam_channel_init(struct bam_device *bdev, struct bam_chan *bchan,
>  }
>  
>  static const struct of_device_id bam_of_match[] = {
> -	{ .compatible = "qcom,bam-v1.3.0", .data = &bam_v1_3_reg_info },
> -	{ .compatible = "qcom,bam-v1.4.0", .data = &bam_v1_4_reg_info },
> -	{ .compatible = "qcom,bam-v1.7.0", .data = &bam_v1_7_reg_info },
> +	{ .compatible = "qcom,bam-v1.3.0", .data = &bam_v1_3_data },
> +	{ .compatible = "qcom,bam-v1.4.0", .data = &bam_v1_4_data },
> +	{ .compatible = "qcom,bam-v1.7.0", .data = &bam_v1_7_data },
>  	{}
>  };
>  
> @@ -1231,7 +1247,7 @@ static int bam_dma_probe(struct platform_device *pdev)
>  		return -ENODEV;
>  	}
>  
> -	bdev->layout = match->data;
> +	bdev->dev_data = match->data;
>  
>  	bdev->regs = devm_platform_ioremap_resource(pdev, 0);
>  	if (IS_ERR(bdev->regs))
> 
> -- 
> 2.47.3
> 

-- 
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