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    SubjectRe: [PATCH V4 1/5] phy: Add new Exynos5 USB 3.0 PHY driver
    Hi Vivek,

    Please see my comments inline.

    On 08.04.2014 16:36, Vivek Gautam wrote:
    > Add a new driver for the USB 3.0 PHY on Exynos5 series of SoCs.
    > The new driver uses the generic PHY framework and will interact
    > with DWC3 controller present on Exynos5 series of SoCs.
    > Thereby, removing old phy-samsung-usb3 driver and related code
    > used untill now which was based on usb/phy framework.
    >
    > Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
    > ---
    > .../devicetree/bindings/phy/samsung-phy.txt | 42 ++
    > drivers/phy/Kconfig | 11 +
    > drivers/phy/Makefile | 1 +
    > drivers/phy/phy-exynos5-usbdrd.c | 668 ++++++++++++++++++++
    > 4 files changed, 722 insertions(+)
    > create mode 100644 drivers/phy/phy-exynos5-usbdrd.c

    [snip]

    > + Additional clock required for Exynos5420:
    > + - usb30_sclk_100m: Additional special clock used for PHY operation
    > + depicted as 'sclk_usbphy30' in CMU of Exynos5420.

    Are you sure this isn't simply a gate for the ref clock, as it can be
    found on another SoC that is not upstream yet? I don't have
    documentation for Exynos 5420 so I can't tell, but I'd like to ask you
    to recheck this.

    > +- samsung,syscon-phandle: phandle for syscon interface, which is used to
    > + control pmu registers for power isolation.
    > +- samsung,pmu-offset: phy power control register offset to pmu-system-controller
    > + base.
    > +- #phy-cells : from the generic PHY bindings, must be 1;
    > +
    > +For "samsung,exynos5250-usbdrd-phy" and "samsung,exynos5420-usbdrd-phy"
    > +compatible PHYs, the second cell in the PHY specifier identifies the
    > +PHY id, which is interpreted as follows:
    > + 0 - UTMI+ type phy,
    > + 1 - PIPE3 type phy,
    > +
    > +Example:
    > + usb3_phy: usbphy@12100000 {
    > + compatible = "samsung,exynos5250-usbdrd-phy";
    > + reg = <0x12100000 0x100>;
    > + clocks = <&clock 286>, <&clock 1>;
    > + clock-names = "phy", "usb3phy_refclk";

    Binding description above doesn't mention "usb3phy_refclk" entry.

    > + samsung,syscon-phandle = <&pmu_syscon>;
    > + samsung,pmu-offset = <0x704>;
    > + #phy-cells = <1>;
    > + };

    [snip]

    > diff --git a/drivers/phy/phy-exynos5-usbdrd.c b/drivers/phy/phy-exynos5-usbdrd.c
    > new file mode 100644
    > index 0000000..ff54a7c
    > --- /dev/null
    > +++ b/drivers/phy/phy-exynos5-usbdrd.c

    [snip]

    > +static int exynos5_usbdrd_phy_probe(struct platform_device *pdev)
    > +{
    > + struct device *dev = &pdev->dev;
    > + struct device_node *node = dev->of_node;
    > + struct exynos5_usbdrd_phy *phy_drd;
    > + struct phy_provider *phy_provider;
    > + struct resource *res;
    > + const struct of_device_id *match;
    > + const struct exynos5_usbdrd_phy_drvdata *drv_data;
    > + struct regmap *reg_pmu;
    > + u32 pmu_offset;
    > + int i;
    > +
    > + /*
    > + * Exynos systems are completely DT enabled,
    > + * so lets not have any platform data support for this driver.
    > + */
    > + if (!node) {
    > + dev_err(dev, "no device node found\n");

    This error message is not very meaningful. I'd rather use something like
    "This driver can be only instantiated using Device Tree".

    > + return -ENODEV;
    > + }
    > +
    > + match = of_match_node(exynos5_usbdrd_phy_of_match, pdev->dev.of_node);
    > + if (!match) {
    > + dev_err(dev, "of_match_node() failed\n");
    > + return -EINVAL;
    > + }
    > + drv_data = match->data;
    > +
    > + phy_drd = devm_kzalloc(dev, sizeof(*phy_drd), GFP_KERNEL);
    > + if (!phy_drd)
    > + return -ENOMEM;
    > +
    > + dev_set_drvdata(dev, phy_drd);
    > + phy_drd->dev = dev;
    > +
    > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    > + phy_drd->reg_phy = devm_ioremap_resource(dev, res);
    > + if (IS_ERR(phy_drd->reg_phy)) {
    > + dev_err(dev, "Failed to map register memory (phy)\n");

    devm_ioremap_resource() already prints an error message.

    Best regards,
    Tomasz


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