Re: [PATCH v3 1/5] PCI: dwc: Refactor dw_pcie_edma_find_chip() API

[Siddharth Vadapalli]

On Mon, Feb 26, 2024 at 05:07:26PM +0530, Manivannan Sadhasivam wrote:
> In order to add support for Hyper DMA (HDMA), let's refactor the existing
> dw_pcie_edma_find_chip() API by moving the common code to separate
> functions.
> 
> No functional change.
> 
> Suggested-by: Serge Semin <fancer.lancer@xxxxxxxxx>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>

Reviewed-by: Siddharth Vadapalli <s-vadapalli@xxxxxx>

Regards,
Siddharth.

> ---
>  drivers/pci/controller/dwc/pcie-designware.c | 52 +++++++++++++++++++++-------
>  1 file changed, 39 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
> index 250cf7f40b85..193fcd86cf93 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.c
> +++ b/drivers/pci/controller/dwc/pcie-designware.c
> @@ -880,7 +880,17 @@ static struct dw_edma_plat_ops dw_pcie_edma_ops = {
>  	.irq_vector = dw_pcie_edma_irq_vector,
>  };
>  
> -static int dw_pcie_edma_find_chip(struct dw_pcie *pci)
> +static void dw_pcie_edma_init_data(struct dw_pcie *pci)
> +{
> +	pci->edma.dev = pci->dev;
> +
> +	if (!pci->edma.ops)
> +		pci->edma.ops = &dw_pcie_edma_ops;
> +
> +	pci->edma.flags |= DW_EDMA_CHIP_LOCAL;
> +}
> +
> +static int dw_pcie_edma_find_mf(struct dw_pcie *pci)
>  {
>  	u32 val;
>  
> @@ -900,24 +910,27 @@ static int dw_pcie_edma_find_chip(struct dw_pcie *pci)
>  	else
>  		val = dw_pcie_readl_dbi(pci, PCIE_DMA_VIEWPORT_BASE + PCIE_DMA_CTRL);
>  
> -	if (val == 0xFFFFFFFF && pci->edma.reg_base) {
> -		pci->edma.mf = EDMA_MF_EDMA_UNROLL;
> -
> -		val = dw_pcie_readl_dma(pci, PCIE_DMA_CTRL);
> -	} else if (val != 0xFFFFFFFF) {
> -		pci->edma.mf = EDMA_MF_EDMA_LEGACY;
> +	/* Set default mapping format here and update it below if needed */
> +	pci->edma.mf = EDMA_MF_EDMA_LEGACY;
>  
> +	if (val == 0xFFFFFFFF && pci->edma.reg_base)
> +		pci->edma.mf = EDMA_MF_EDMA_UNROLL;
> +	else if (val != 0xFFFFFFFF)
>  		pci->edma.reg_base = pci->dbi_base + PCIE_DMA_VIEWPORT_BASE;
> -	} else {
> +	else
>  		return -ENODEV;
> -	}
>  
> -	pci->edma.dev = pci->dev;
> +	return 0;
> +}
>  
> -	if (!pci->edma.ops)
> -		pci->edma.ops = &dw_pcie_edma_ops;
> +static int dw_pcie_edma_find_channels(struct dw_pcie *pci)
> +{
> +	u32 val;
>  
> -	pci->edma.flags |= DW_EDMA_CHIP_LOCAL;
> +	if (pci->edma.mf == EDMA_MF_EDMA_LEGACY)
> +		val = dw_pcie_readl_dbi(pci, PCIE_DMA_VIEWPORT_BASE + PCIE_DMA_CTRL);
> +	else
> +		val = dw_pcie_readl_dma(pci, PCIE_DMA_CTRL);
>  
>  	pci->edma.ll_wr_cnt = FIELD_GET(PCIE_DMA_NUM_WR_CHAN, val);
>  	pci->edma.ll_rd_cnt = FIELD_GET(PCIE_DMA_NUM_RD_CHAN, val);
> @@ -930,6 +943,19 @@ static int dw_pcie_edma_find_chip(struct dw_pcie *pci)
>  	return 0;
>  }
>  
> +static int dw_pcie_edma_find_chip(struct dw_pcie *pci)
> +{
> +	int ret;
> +
> +	dw_pcie_edma_init_data(pci);
> +
> +	ret = dw_pcie_edma_find_mf(pci);
> +	if (ret)
> +		return ret;
> +
> +	return dw_pcie_edma_find_channels(pci);
> +}
> +
>  static int dw_pcie_edma_irq_verify(struct dw_pcie *pci)
>  {
>  	struct platform_device *pdev = to_platform_device(pci->dev);
> 
> -- 
> 2.25.1
> 
>