Re: [PATCH 3/3] phy: bcm-ns-usb2: support updated single CRU reg DT binding

["Rafał Miłecki" <zajec5@gmail.com>]

Cc linux-phy@

On 26.02.2021 12:45, Rafał Miłecki wrote:
> From: Rafał Miłecki <rafal@milecki.pl>
> 
> Updated DT binding maps a single CRU register that is directly used for
> the PHY control. Accessing common CRU reg is handled using syscon &
> regmap.
> 
> The old binding has been deprecated and stays as a fallback method.
> 
> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> ---
> It's a reworked version of my abonded 2019 patch:
> [PATCH V2 2/2] phy: bcm-ns-usb2: support updated DT binding with the CRU syscon
> https://lore.kernel.org/patchwork/patch/1029863/
> ---
>   drivers/phy/broadcom/phy-bcm-ns-usb2.c | 52 +++++++++++++++++++++-----
>   1 file changed, 43 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/phy/broadcom/phy-bcm-ns-usb2.c b/drivers/phy/broadcom/phy-bcm-ns-usb2.c
> index 4b015b8a71c3..98d32729a45d 100644
> --- a/drivers/phy/broadcom/phy-bcm-ns-usb2.c
> +++ b/drivers/phy/broadcom/phy-bcm-ns-usb2.c
> @@ -9,17 +9,23 @@
>   #include <linux/clk.h>
>   #include <linux/delay.h>
>   #include <linux/err.h>
> +#include <linux/mfd/syscon.h>
>   #include <linux/module.h>
>   #include <linux/of_address.h>
>   #include <linux/of_platform.h>
>   #include <linux/phy/phy.h>
>   #include <linux/platform_device.h>
> +#include <linux/regmap.h>
>   #include <linux/slab.h>
>   
>   struct bcm_ns_usb2 {
>   	struct device *dev;
>   	struct clk *ref_clk;
>   	struct phy *phy;
> +	struct regmap *clkset;
> +	void __iomem *base;
> +
> +	/* Deprecated binding */
>   	void __iomem *dmu;
>   };
>   
> @@ -27,7 +33,6 @@ static int bcm_ns_usb2_phy_init(struct phy *phy)
>   {
>   	struct bcm_ns_usb2 *usb2 = phy_get_drvdata(phy);
>   	struct device *dev = usb2->dev;
> -	void __iomem *dmu = usb2->dmu;
>   	u32 ref_clk_rate, usb2ctl, usb_pll_ndiv, usb_pll_pdiv;
>   	int err = 0;
>   
> @@ -44,7 +49,10 @@ static int bcm_ns_usb2_phy_init(struct phy *phy)
>   		goto err_clk_off;
>   	}
>   
> -	usb2ctl = readl(dmu + BCMA_DMU_CRU_USB2_CONTROL);
> +	if (usb2->base)
> +		usb2ctl = readl(usb2->base);
> +	else
> +		usb2ctl = readl(usb2->dmu + BCMA_DMU_CRU_USB2_CONTROL);
>   
>   	if (usb2ctl & BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_PDIV_MASK) {
>   		usb_pll_pdiv = usb2ctl;
> @@ -58,15 +66,24 @@ static int bcm_ns_usb2_phy_init(struct phy *phy)
>   	usb_pll_ndiv = (1920000000 * usb_pll_pdiv) / ref_clk_rate;
>   
>   	/* Unlock DMU PLL settings with some magic value */
> -	writel(0x0000ea68, dmu + BCMA_DMU_CRU_CLKSET_KEY);
> +	if (usb2->clkset)
> +		regmap_write(usb2->clkset, 0, 0x0000ea68);
> +	else
> +		writel(0x0000ea68, usb2->dmu + BCMA_DMU_CRU_CLKSET_KEY);
>   
>   	/* Write USB 2.0 PLL control setting */
>   	usb2ctl &= ~BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_NDIV_MASK;
>   	usb2ctl |= usb_pll_ndiv << BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_NDIV_SHIFT;
> -	writel(usb2ctl, dmu + BCMA_DMU_CRU_USB2_CONTROL);
> +	if (usb2->base)
> +		writel(usb2ctl, usb2->base);
> +	else
> +		writel(usb2ctl, usb2->dmu + BCMA_DMU_CRU_USB2_CONTROL);
>   
>   	/* Lock DMU PLL settings */
> -	writel(0x00000000, dmu + BCMA_DMU_CRU_CLKSET_KEY);
> +	if (usb2->clkset)
> +		regmap_write(usb2->clkset, 0, 0x00000000);
> +	else
> +		writel(0x00000000, usb2->dmu + BCMA_DMU_CRU_CLKSET_KEY);
>   
>   err_clk_off:
>   	clk_disable_unprepare(usb2->ref_clk);
> @@ -90,10 +107,27 @@ static int bcm_ns_usb2_probe(struct platform_device *pdev)
>   		return -ENOMEM;
>   	usb2->dev = dev;
>   
> -	usb2->dmu = devm_platform_ioremap_resource_byname(pdev, "dmu");
> -	if (IS_ERR(usb2->dmu)) {
> -		dev_err(dev, "Failed to map DMU regs\n");
> -		return PTR_ERR(usb2->dmu);
> +	if (of_find_property(dev->of_node, "brcm,syscon-clkset", NULL)) {
> +		usb2->base = devm_platform_ioremap_resource(pdev, 0);
> +		if (IS_ERR(usb2->base)) {
> +			dev_err(dev, "Failed to map control reg\n");
> +			return PTR_ERR(usb2->base);
> +		}
> +
> +		usb2->clkset = syscon_regmap_lookup_by_phandle(dev->of_node,
> +							       "brcm,syscon-clkset");
> +		if (IS_ERR(usb2->clkset)) {
> +			dev_err(dev, "Failed to lookup clkset regmap\n");
> +			return PTR_ERR(usb2->clkset);
> +		}
> +	} else {
> +		usb2->dmu = devm_platform_ioremap_resource_byname(pdev, "dmu");
> +		if (IS_ERR(usb2->dmu)) {
> +			dev_err(dev, "Failed to map DMU regs\n");
> +			return PTR_ERR(usb2->dmu);
> +		}
> +
> +		dev_warn(dev, "using deprecated DT binding\n");
>   	}
>   
>   	usb2->ref_clk = devm_clk_get(dev, "phy-ref-clk");
>