Re: [PATCH 4/8] mmc: sdhci-pxav3: enable proper resuming on Armada 38x SoC

[Jisheng Zhang <jszhang@marvell.com>]

Hi Marcin,

On Tue, 6 Oct 2015 03:22:38 +0200
Marcin Wojtas <mw@semihalf.com> wrote:

> When resuming from suspend on Armada 38x SoC MBus windows have to be
> re-configured and for that purpose mv_conf_mbus_windows function needed
> rework. MBus windows register base address obtaining was moved to
> armada_38x_quirks function in order to be kept in pxa global structure,
> because it is used during a resume.
> 
> This commit fixes resuming from suspend by calling MBus windows
> configuration routine and therefore enabling proper DMA operation.
> 
> Signed-off-by: Marcin Wojtas <mw@semihalf.com>
> ---
>  drivers/mmc/host/sdhci-pxav3.c | 39 ++++++++++++++++++++-------------------
>  1 file changed, 20 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-pxav3.c b/drivers/mmc/host/sdhci-pxav3.c
> index f5edf9d..3f71894 100644
> --- a/drivers/mmc/host/sdhci-pxav3.c
> +++ b/drivers/mmc/host/sdhci-pxav3.c
> @@ -63,6 +63,7 @@ struct sdhci_pxa {
>  	struct clk *clk_io;
>  	u8	power_mode;
>  	void __iomem *sdio3_conf_reg;
> +	void __iomem *mbus_win_regs;
>  };
>  
>  /*
> @@ -81,30 +82,16 @@ struct sdhci_pxa {
>  #define SDIO3_CONF_CLK_INV	BIT(0)
>  #define SDIO3_CONF_SD_FB_CLK	BIT(2)
>  
> -static int mv_conf_mbus_windows(struct platform_device *pdev,
> +static int mv_conf_mbus_windows(struct device *dev, void __iomem *regs,
>  				const struct mbus_dram_target_info *dram)
>  {
>  	int i;
> -	void __iomem *regs;
> -	struct resource *res;
>  
>  	if (!dram) {
> -		dev_err(&pdev->dev, "no mbus dram info\n");
> -		return -EINVAL;
> -	}
> -
> -	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> -	if (!res) {
> -		dev_err(&pdev->dev, "cannot get mbus registers\n");
> +		dev_err(dev, "no mbus dram info\n");
>  		return -EINVAL;
>  	}
>  
> -	regs = ioremap(res->start, resource_size(res));
> -	if (!regs) {
> -		dev_err(&pdev->dev, "cannot map mbus registers\n");
> -		return -ENOMEM;
> -	}
> -
>  	for (i = 0; i < SDHCI_MAX_WIN_NUM; i++) {
>  		writel(0, regs + SDHCI_WINDOW_CTRL(i));
>  		writel(0, regs + SDHCI_WINDOW_BASE(i));
> @@ -122,8 +109,6 @@ static int mv_conf_mbus_windows(struct platform_device *pdev,
>  		writel(cs->base, regs + SDHCI_WINDOW_BASE(i));
>  	}
>  
> -	iounmap(regs);
> -
>  	return 0;
>  }
>  
> @@ -135,6 +120,14 @@ static int armada_38x_quirks(struct platform_device *pdev,
>  	struct sdhci_pxa *pxa = pltfm_host->priv;
>  	struct resource *res;
>  
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mbus");
> +	pxa->mbus_win_regs = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(pxa->mbus_win_regs)) {
> +		dev_err(mmc_dev(host->mmc),
> +			"failed to obtain MBus windows register base\n");

devm_ioremap_resource() has warned us if it fails, so is it better to remove
this dev_err() here?

> +		return PTR_ERR(pxa->mbus_win_regs);
> +	}
> +
>  	host->quirks &= ~SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN;
>  	host->quirks |= SDHCI_QUIRK_MISSING_CAPS;
>  	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> @@ -403,7 +396,8 @@ static int sdhci_pxav3_probe(struct platform_device *pdev)
>  		ret = armada_38x_quirks(pdev, host);
>  		if (ret < 0)
>  			goto err_mbus_win;
> -		ret = mv_conf_mbus_windows(pdev, mv_mbus_dram_info());
> +		ret = mv_conf_mbus_windows(&pdev->dev, pxa->mbus_win_regs,
> +					   mv_mbus_dram_info());
>  		if (ret < 0)
>  			goto err_mbus_win;
>  	}
> @@ -520,6 +514,13 @@ static int sdhci_pxav3_resume(struct device *dev)
>  {
>  	int ret;
>  	struct sdhci_host *host = dev_get_drvdata(dev);
> +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +	struct sdhci_pxa *pxa = pltfm_host->priv;
> +	struct device_node *np = dev->of_node;
> +
> +	if (of_device_is_compatible(np, "marvell,armada-380-sdhci"))

this would increase resume time especially those non armada-380-sdhci host
although it's trivial. Is it better to check "if (pxa->mbus_win_regs)"?

> +		ret = mv_conf_mbus_windows(dev, pxa->mbus_win_regs,
> +					   mv_mbus_dram_info());
>  
>  	pm_runtime_get_sync(dev);
>  	ret = sdhci_resume_host(host);