Re: [PATCH 2/2] phy: bcm-ns-usb2: support updated DT binding with the CRU syscon

From: Ray Jui
Date: Mon Jan 07 2019 - 13:47:44 EST




On 1/7/2019 12:25 AM, RafaÅ MiÅecki wrote:
> From: RafaÅ MiÅecki <rafal@xxxxxxxxxx>
>
> This adds support for the "syscon-cru" DT property which simply requires
> using regmap to access CRU registers.
>
> The old binding has been deprecated and stays as a fallback method.
>
> Signed-off-by: RafaÅ MiÅecki <rafal@xxxxxxxxxx>
> ---
> drivers/phy/broadcom/phy-bcm-ns-usb2.c | 44 +++++++++++++++++++++++++++-------
> 1 file changed, 35 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/phy/broadcom/phy-bcm-ns-usb2.c b/drivers/phy/broadcom/phy-bcm-ns-usb2.c
> index 58dff80e9386..8dc6835b941c 100644
> --- a/drivers/phy/broadcom/phy-bcm-ns-usb2.c
> +++ b/drivers/phy/broadcom/phy-bcm-ns-usb2.c
> @@ -13,17 +13,23 @@
> #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/regmap.h>

alphabetical order, so after platform_device.h

> #include <linux/phy/phy.h>
> #include <linux/platform_device.h>
> #include <linux/slab.h>
>
> +#define CRU_USB2_CONTROL 0x64
> +#define CRU_CLKSET_KEY 0x80
> +
> struct bcm_ns_usb2 {
> struct device *dev;
> struct clk *ref_clk;
> struct phy *phy;
> + struct regmap *cru;
> void __iomem *dmu;
> };
>
> @@ -31,6 +37,7 @@ static int bcm_ns_usb2_phy_init(struct phy *phy)
> {
> struct bcm_ns_usb2 *usb2 = phy_get_drvdata(phy);
> struct device *dev = usb2->dev;
> + struct regmap *cru = usb2->cru;
> void __iomem *dmu = usb2->dmu;
> u32 ref_clk_rate, usb2ctl, usb_pll_ndiv, usb_pll_pdiv;
> int err = 0;
> @@ -48,7 +55,10 @@ static int bcm_ns_usb2_phy_init(struct phy *phy)
> goto err_clk_off;
> }
>
> - usb2ctl = readl(dmu + BCMA_DMU_CRU_USB2_CONTROL);
> + if (cru)
> + regmap_read(cru, CRU_USB2_CONTROL, &usb2ctl);
> + else
> + usb2ctl = readl(dmu + BCMA_DMU_CRU_USB2_CONTROL);

Do you think it's cleaner to use a read/write wrapper to handle both the
syscon based case and the plain readl/writel? I thought that would make
the code much more readable.

>
> if (usb2ctl & BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_PDIV_MASK) {
> usb_pll_pdiv = usb2ctl;
> @@ -62,15 +72,24 @@ 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 (cru)
> + regmap_write(cru, CRU_CLKSET_KEY, 0x0000ea68);
> + else
> + writel(0x0000ea68, 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 (cru)
> + regmap_write(cru, CRU_USB2_CONTROL, usb2ctl);
> + else
> + writel(usb2ctl, dmu + BCMA_DMU_CRU_USB2_CONTROL);
>
> /* Lock DMU PLL settings */
> - writel(0x00000000, dmu + BCMA_DMU_CRU_CLKSET_KEY);
> + if (cru)
> + regmap_write(cru, CRU_CLKSET_KEY, 0x00000000);
> + else
> + writel(0x00000000, dmu + BCMA_DMU_CRU_CLKSET_KEY);
>
> err_clk_off:
> clk_disable_unprepare(usb2->ref_clk);
> @@ -86,6 +105,7 @@ static const struct phy_ops ops = {
> static int bcm_ns_usb2_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> + struct device_node *cru_np;
> struct bcm_ns_usb2 *usb2;
> struct resource *res;
> struct phy_provider *phy_provider;
> @@ -95,11 +115,17 @@ static int bcm_ns_usb2_probe(struct platform_device *pdev)
> return -ENOMEM;
> usb2->dev = dev;
>
> - res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dmu");
> - usb2->dmu = devm_ioremap_resource(dev, res);
> - if (IS_ERR(usb2->dmu)) {
> - dev_err(dev, "Failed to map DMU regs\n");
> - return PTR_ERR(usb2->dmu);
> + cru_np = of_parse_phandle(dev->of_node, "syscon-cru", 0);
> + usb2->cru = syscon_node_to_regmap(cru_np);

just use 'syscon_regmap_lookup_by_phandle'

> + if (IS_ERR(usb2->cru)) {
> + usb2->cru = NULL;
> +
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dmu");
> + usb2->dmu = devm_ioremap_resource(dev, res);
> + if (IS_ERR(usb2->dmu)) {
> + dev_err(dev, "Failed to map DMU regs\n");
> + return PTR_ERR(usb2->dmu);
> + }
> }
>
> usb2->ref_clk = devm_clk_get(dev, "phy-ref-clk");
>