Messages in this thread Patch in this message | | | Date | Wed, 19 Dec 2012 00:19:06 +0100 | From | Sylwester Nawrocki <> | Subject | Re: [PATCH v2] usb: phy: samsung: Add support to set pmu isolation |
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Hi Vivek,
On 12/18/2012 02:56 PM, Vivek Gautam wrote: > Adding support to parse device node data in order to get > required properties to set pmu isolation for usb-phy. > > Signed-off-by: Vivek Gautam<gautam.vivek@samsung.com> > --- > > Changes from v1: > - Changed the name of property for phy handler from'samsung,usb-phyctrl' > to 'samsung,usb-phyhandle' to make it look more generic. > - Similarly 'samsung,phyctrl-reg' is changed to 'samsung,phyhandle-reg' > - Added a check for 'samsung,usb-phyhandle' before getting node from > phandle. > - Putting the node using 'of_node_put()' which had been missed. > - Adding necessary check for the pointer in 'samsung_usbphy_set_isolation()' > to avoid any NULL pointer dereferencing. > - Unmapping the register ioremapped in 'samsung_usbphy_parse_dt_param()'. > > > .../devicetree/bindings/usb/samsung-usbphy.txt | 12 +++ > drivers/usb/phy/samsung-usbphy.c | 94 ++++++++++++++++++-- > 2 files changed, 98 insertions(+), 8 deletions(-) > > diff --git a/Documentation/devicetree/bindings/usb/samsung-usbphy.txt b/Documentation/devicetree/bindings/usb/samsung-usbphy.txt > index 7b26e2d..a7b28b2 100644 > --- a/Documentation/devicetree/bindings/usb/samsung-usbphy.txt > +++ b/Documentation/devicetree/bindings/usb/samsung-usbphy.txt > @@ -9,3 +9,15 @@ Required properties: > - compatible : should be "samsung,exynos4210-usbphy" > - reg : base physical address of the phy registers and length of memory mapped > region. > + > +Optional properties: > +- samsung,usb-phyhandle : should point to usb-phyhandle sub-node which provides > + binding data to enable/disable device PHY handled by > + PMU register. > + > + Required properties: > + - compatible : should be "samsung,usbdev-phyctrl" for > + DEVICE type phy. > + - samsung,phyhandle-reg: base physical address of > + PHY_CONTROL register in PMU. > +- samsung,enable-mask : should be '1'
This should only be 1 for Exynos4210+ SoCs, right ? S5PV210 uses bit 0 for OTG and bit1 for USB host, doesn't it ? And for s3c64xx it seems to be bit 16.
How about deriving this information from 'compatible' property instead ?
Maybe you could just encode the USB PMU registers (I assume those aren't touched by anything but the usb drivers) in a regular 'reg' property in an usbphy subnode. Then the driver could interpret it also with help of 'compatible' property. And you could just use of_iomap(). E.g.
usbphy@12130000 { compatible = "samsung,exynos5250-usbphy"; reg = <0x12130000 0x100>, <0x12100000 0x100>; usbphy-pmu { /* USB device and host PHY_CONTROL registers */ reg = <0x10040704 8>; }; };
Your "samsung,usb-phyhandle" approach seems over-engineered to me. I might be missing something though.
> diff --git a/drivers/usb/phy/samsung-usbphy.c b/drivers/usb/phy/samsung-usbphy.c > index 5c5e1bb5..4ceabe3 100644 > --- a/drivers/usb/phy/samsung-usbphy.c > +++ b/drivers/usb/phy/samsung-usbphy.c > @@ -72,6 +72,8 @@ enum samsung_cpu_type { > * @dev: The parent device supplied to the probe function > * @clk: usb phy clock > * @regs: usb phy register memory base > + * @devctrl_reg: usb device phy-control pmu register memory base
hum, this name is not really helpful in understanding what's going on here.
Looking at arch/arm/mach-s5pv210/setup-usb-phy.c, there is only one PHY_CONTROL (Power Management Unit) register for both OTG and USB host PHYs. So are you really taking care of that case as well ?
> + * @en_mask: enable mask > * @ref_clk_freq: reference clock frequency selection > * @cpu_type: machine identifier > */ > @@ -81,12 +83,73 @@ struct samsung_usbphy { > struct device *dev; > struct clk *clk; > void __iomem *regs; > + void __iomem *devctrl_reg; > + u32 en_mask; > int ref_clk_freq; > int cpu_type; > }; > > #define phy_to_sphy(x) container_of((x), struct samsung_usbphy, phy) > > +static int samsung_usbphy_parse_dt_param(struct samsung_usbphy *sphy) > +{ > + struct device_node *usb_phyctrl; > + u32 reg; > + int lenp; > + > + if (!sphy->dev->of_node) { > + sphy->devctrl_reg = NULL; > + return -ENODEV; > + } > + > + if (of_get_property(sphy->dev->of_node, "samsung,usb-phyhandle",&lenp)) { > + usb_phyctrl = of_parse_phandle(sphy->dev->of_node, > + "samsung,usb-phyhandle", 0); > + if (!usb_phyctrl) { > + dev_warn(sphy->dev, "Can't get usb-phy handle\n"); > + sphy->devctrl_reg = NULL; > + } > + > + of_property_read_u32(usb_phyctrl, "samsung,phyhandle-reg",®); > + > + sphy->devctrl_reg = ioremap(reg, SZ_4);
What happens if invalid address value is assigned to 'samsung,phyhandle-reg' ?
> + of_property_read_u32(sphy->dev->of_node, "samsung,enable-mask", > + &sphy->en_mask); > + of_node_put(usb_phyctrl); > + } else { > + dev_warn(sphy->dev, "Can't get usb-phy handle\n"); > + sphy->devctrl_reg = NULL; > + } > + > + return 0; > +} > + > +/* > + * Set isolation here for phy. > + * SOCs control this by controlling corresponding PMU registers > + */ > +static void samsung_usbphy_set_isolation(struct samsung_usbphy *sphy, int on) > +{ > + void __iomem *usb_phyctrl_reg; > + u32 en_mask = sphy->en_mask; > + u32 reg; > + > + usb_phyctrl_reg = sphy->devctrl_reg; > + > + if (!usb_phyctrl_reg) { > + dev_warn(sphy->dev, "Can't set pmu isolation\n"); > + return; > + } > + > + reg = readl(usb_phyctrl_reg); > + > + if (on) > + writel(reg& ~en_mask, usb_phyctrl_reg); > + else > + writel(reg | en_mask, usb_phyctrl_reg); > +} > + > /* > * Returns reference clock frequency selection value > */ > @@ -199,6 +262,8 @@ static int samsung_usbphy_init(struct usb_phy *phy) > /* Disable phy isolation */ > if (sphy->plat&& sphy->plat->pmu_isolation) > sphy->plat->pmu_isolation(false); > + else > + samsung_usbphy_set_isolation(sphy, false); > > /* Initialize usb phy registers */ > samsung_usbphy_enable(sphy); > @@ -228,6 +293,8 @@ static void samsung_usbphy_shutdown(struct usb_phy *phy) > /* Enable phy isolation */ > if (sphy->plat&& sphy->plat->pmu_isolation) > sphy->plat->pmu_isolation(true); > + else > + samsung_usbphy_set_isolation(sphy, true); > > clk_disable_unprepare(sphy->clk); > } > @@ -249,17 +316,12 @@ static inline int samsung_usbphy_get_driver_data(struct platform_device *pdev) > static int __devinit samsung_usbphy_probe(struct platform_device *pdev) > { > struct samsung_usbphy *sphy; > - struct samsung_usbphy_data *pdata; > + struct samsung_usbphy_data *pdata = pdev->dev.platform_data; > struct device *dev =&pdev->dev; > struct resource *phy_mem; > void __iomem *phy_base; > struct clk *clk; > - > - pdata = pdev->dev.platform_data; > - if (!pdata) { > - dev_err(&pdev->dev, "%s: no platform data defined\n", __func__); > - return -EINVAL; > - } > + int ret; > > phy_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); > if (!phy_mem) { > @@ -283,7 +345,20 @@ static int __devinit samsung_usbphy_probe(struct platform_device *pdev) > return PTR_ERR(clk); > } > > - sphy->dev =&pdev->dev; > + sphy->dev =&pdev->dev;
sphy->dev = dev;
> + > + ret = samsung_usbphy_parse_dt_param(sphy); > + if (ret) { > + /* fallback to pdata */ > + if (!pdata) { > + dev_err(&pdev->dev, > + "%s: no device data found\n", __func__);
I find term "device data" a bit confusing here.
> + return -ENODEV;
In the original code -EINVAL was returned when platform_data was not set.
> + } else { > + sphy->plat = pdata; > + } > + } > +
How about rewriting this to: if (dev->of_node) { ret = samsung_usbphy_parse_dt_param(sphy); if (ret < 0) return ret; } else { if (!pdata) { dev_err(dev, "no platform data specified\n"); return -EINVAL; } } This way we won't be obfuscating any error code returned from the OF parsing function.
> sphy->plat = pdata; > sphy->regs = phy_base; > sphy->clk = clk; > @@ -305,6 +380,9 @@ static int __exit samsung_usbphy_remove(struct platform_device *pdev) > > usb_remove_phy(&sphy->phy); > > + if (sphy->devctrl_reg) > + iounmap(sphy->devctrl_reg); > + > return 0; > }
--
Regards, Sylwester
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