[PATCH v3 04/12] PCI: brcmstb: Use bridge reset if available

[Amit Singh Tomar <amitsinght@xxxxxxxxxxx>]

On 7/11/2024 3:46 AM, Jim Quinlan wrote:
> The 7712 SOC has a bridge reset which can be described in the device tree.
> If it is present, use it. Otherwise, continue to use the legacy method to
> reset the bridge.
>
> Signed-off-by: Jim Quinlan <james.quinlan@xxxxxxxxxxxx>
> ---
>   drivers/pci/controller/pcie-brcmstb.c | 22 +++++++++++++++++-----
>   1 file changed, 17 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
> index c257434edc08..92816d8d215a 100644
> --- a/drivers/pci/controller/pcie-brcmstb.c
> +++ b/drivers/pci/controller/pcie-brcmstb.c
> @@ -265,6 +265,7 @@ struct brcm_pcie {
>   	enum pcie_type		type;
>   	struct reset_control	*rescal;
>   	struct reset_control	*perst_reset;
> +	struct reset_control	*bridge;
>   	int			num_memc;
>   	u64			memc_size[PCIE_BRCM_MAX_MEMC];
>   	u32			hw_rev;
> @@ -732,12 +733,19 @@ static void __iomem *brcm7425_pcie_map_bus(struct pci_bus *bus,
>   
>   static void brcm_pcie_bridge_sw_init_set_generic(struct brcm_pcie *pcie, u32 val)
>   {
> -	u32 tmp, mask =  RGR1_SW_INIT_1_INIT_GENERIC_MASK;
> -	u32 shift = RGR1_SW_INIT_1_INIT_GENERIC_SHIFT;
> +	if (pcie->bridge) {
> +		if (val)
> +			reset_control_assert(pcie->bridge);
> +		else
> +			reset_control_deassert(pcie->bridge);
> +	} else {
> +		u32 tmp, mask =  RGR1_SW_INIT_1_INIT_GENERIC_MASK;
> +		u32 shift = RGR1_SW_INIT_1_INIT_GENERIC_SHIFT;
>   
> -	tmp = readl(pcie->base + PCIE_RGR1_SW_INIT_1(pcie));
> -	tmp = (tmp & ~mask) | ((val << shift) & mask);
> -	writel(tmp, pcie->base + PCIE_RGR1_SW_INIT_1(pcie));
> +		tmp = readl(pcie->base + PCIE_RGR1_SW_INIT_1(pcie));
> +		tmp = (tmp & ~mask) | ((val << shift) & mask);
> +		writel(tmp, pcie->base + PCIE_RGR1_SW_INIT_1(pcie));
> +	}
>   }
>   
>   static void brcm_pcie_bridge_sw_init_set_7278(struct brcm_pcie *pcie, u32 val)
> @@ -1621,6 +1629,10 @@ static int brcm_pcie_probe(struct platform_device *pdev)
>   	if (IS_ERR(pcie->perst_reset))
>   		return PTR_ERR(pcie->perst_reset);
>   
> +	pcie->bridge = devm_reset_control_get_optional_exclusive(&pdev->dev, "bridge");
> +	if (IS_ERR(pcie->bridge))
> +		return PTR_ERR(pcie->bridge);
How about using "dev_err_probe," which utilizes "dev_err" for logging 
error messages and recording the deferred probe reason?
> +
>   	ret = clk_prepare_enable(pcie->clk);
>   	if (ret) {
>   		dev_err(&pdev->dev, "could not enable clock\n");