linux-kernel - Re: [PATCH] PCI: exynos: Adapt to clk_bulk

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Message-ID: <20231027134849.GA23716@thinkpad>
Date:   Fri, 27 Oct 2023 19:18:49 +0530
From:   Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
To:     Shradha Todi <shradha.t@...sung.com>
Cc:     jingoohan1@...il.com, lpieralisi@...nel.org, kw@...ux.com,
        robh@...nel.org, bhelgaas@...gle.com,
        krzysztof.kozlowski@...aro.org, alim.akhtar@...sung.com,
        linux-pci@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-samsung-soc@...r.kernel.org, linux-kernel@...r.kernel.org,
        pankaj.dubey@...sung.com
Subject: Re: [PATCH] PCI: exynos: Adapt to clk_bulk_* APIs

On Mon, Oct 09, 2023 at 11:52:16AM +0530, Shradha Todi wrote:
> There is no need to hardcode the clock info in the driver as driver can
> rely on the devicetree to supply the clocks required for the functioning
> of the peripheral. Get rid of the static clock info and obtain the
> platform supplied clocks. The total number of clocks supplied is
> obtained using the devm_clk_bulk_get_all() API and used for the rest of
> the clk_bulk_* APIs.
> 
> Signed-off-by: Shradha Todi <shradha.t@...sung.com>
> ---
>  drivers/pci/controller/dwc/pci-exynos.c | 46 ++++++-------------------
>  1 file changed, 11 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pci-exynos.c b/drivers/pci/controller/dwc/pci-exynos.c
> index 9e42cfcd99cc..023cf41fccd7 100644
> --- a/drivers/pci/controller/dwc/pci-exynos.c
> +++ b/drivers/pci/controller/dwc/pci-exynos.c
> @@ -54,8 +54,8 @@
>  struct exynos_pcie {
>  	struct dw_pcie			pci;
>  	void __iomem			*elbi_base;
> -	struct clk			*clk;
> -	struct clk			*bus_clk;
> +	struct clk_bulk_data		*clks;
> +	int				clk_cnt;
>  	struct phy			*phy;
>  	struct regulator_bulk_data	supplies[2];
>  };
> @@ -65,30 +65,18 @@ static int exynos_pcie_init_clk_resources(struct exynos_pcie *ep)
>  	struct device *dev = ep->pci.dev;
>  	int ret;
>  
> -	ret = clk_prepare_enable(ep->clk);
> -	if (ret) {
> -		dev_err(dev, "cannot enable pcie rc clock");
> +	ret = devm_clk_bulk_get_all(dev, &ep->clks);
> +	if (ret < 0)

Please use !(ret) here and below to be consistent with the driver.

>  		return ret;
> -	}
>  
> -	ret = clk_prepare_enable(ep->bus_clk);
> -	if (ret) {
> -		dev_err(dev, "cannot enable pcie bus clock");
> -		goto err_bus_clk;
> -	}
> +	ep->clk_cnt = ret;

Since clk_cnt is "int", you can just use it directly instead of "ret".

>  
> -	return 0;
> -
> -err_bus_clk:
> -	clk_disable_unprepare(ep->clk);
> -
> -	return ret;
> +	return clk_bulk_prepare_enable(ep->clk_cnt, ep->clks);
>  }
>  
>  static void exynos_pcie_deinit_clk_resources(struct exynos_pcie *ep)
>  {
> -	clk_disable_unprepare(ep->bus_clk);
> -	clk_disable_unprepare(ep->clk);
> +	clk_bulk_disable_unprepare(ep->clk_cnt, ep->clks);
>  }
>  
>  static void exynos_pcie_writel(void __iomem *base, u32 val, u32 reg)
> @@ -332,17 +320,9 @@ static int exynos_pcie_probe(struct platform_device *pdev)
>  	if (IS_ERR(ep->elbi_base))
>  		return PTR_ERR(ep->elbi_base);
>  
> -	ep->clk = devm_clk_get(dev, "pcie");
> -	if (IS_ERR(ep->clk)) {
> -		dev_err(dev, "Failed to get pcie rc clock\n");
> -		return PTR_ERR(ep->clk);
> -	}
> -
> -	ep->bus_clk = devm_clk_get(dev, "pcie_bus");
> -	if (IS_ERR(ep->bus_clk)) {
> -		dev_err(dev, "Failed to get pcie bus clock\n");
> -		return PTR_ERR(ep->bus_clk);
> -	}
> +	ret = exynos_pcie_init_clk_resources(ep);
> +	if (ret < 0)
> +		return ret;
>  
>  	ep->supplies[0].supply = "vdd18";
>  	ep->supplies[1].supply = "vdd10";
> @@ -351,10 +331,6 @@ static int exynos_pcie_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> -	ret = exynos_pcie_init_clk_resources(ep);
> -	if (ret)
> -		return ret;
> -
>  	ret = regulator_bulk_enable(ARRAY_SIZE(ep->supplies), ep->supplies);
>  	if (ret)

You need to disable_unprepare() clocks in error path here and above.

- Mani

-- 
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