[PATCH] usb: phy: samsung: Add support to set pmu isolation

[PATCH] usb: phy: samsung: Add support to set pmu isolation

[Vivek Gautam]

Based on patches for samsung-usbphy driver available at:
https://patchwork.kernel.org/patch/1794651/

In this patch we are adding support to parse device tree data for
samsung-usbphy driver and further setting pmu_isolation to
enable/disable phy as and when needed.
This further chucks out the need of platform data for samsung-usbphy on
DT enabled system and hence serves the purpose of the discussion
in the thread for:
[PATCH v8 2/2] usb: s3c-hsotg: Adding phy driver support

Vivek Gautam (1):
  usb: phy: samsung: Add support to set pmu isolation

 .../devicetree/bindings/usb/samsung-usbphy.txt     |   10 +++
 drivers/usb/phy/samsung-usbphy.c                   |   80 ++++++++++++++++++--
 2 files changed, 82 insertions(+), 8 deletions(-)

-- 
1.7.6.5

[PATCH] usb: phy: samsung: Add support to set pmu isolation

[Vivek Gautam]

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>
---
 .../devicetree/bindings/usb/samsung-usbphy.txt     |   10 +++
 drivers/usb/phy/samsung-usbphy.c                   |   80 ++++++++++++++++++--
 2 files changed, 82 insertions(+), 8 deletions(-)

diff --git a/Documentation/devicetree/bindings/usb/samsung-usbphy.txt b/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
index 7b26e2d..112eaa6 100644
--- a/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
+++ b/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
@@ -9,3 +9,13 @@ Required properties:
 - compatible : should be "samsung,exynos4210-usbphy"
 - reg : base physical address of the phy registers and length of memory mapped
 	region.
+- samsung,usb-phyctrl : should point to usb-phyctrl 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,phyctrl-reg: base physical address of
+						PHY_CONTROL register in PMU.
+- samsung,enable-mask : should be '1'
diff --git a/drivers/usb/phy/samsung-usbphy.c b/drivers/usb/phy/samsung-usbphy.c
index 5c5e1bb5..ef394c3 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 phy-control pmu register memory base
+ * @en_mask: enable mask
  * @ref_clk_freq: reference clock frequency selection
  * @cpu_type: machine identifier
  */
@@ -81,12 +83,62 @@ 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;
+
+	if (!sphy->dev->of_node) {
+		sphy->devctrl_reg = NULL;
+		return -ENODEV;
+	}
+
+	usb_phyctrl = of_parse_phandle(sphy->dev->of_node,
+					"samsung,usb-phyctrl", 0);
+	if (!usb_phyctrl) {
+		dev_dbg(sphy->dev, "Can't get usb-phy control node\n");
+		sphy->devctrl_reg = NULL;
+		return -ENODEV;
+	}
+
+	of_property_read_u32(usb_phyctrl, "samsung,phyctrl-reg", &reg);
+
+	sphy->devctrl_reg = ioremap(reg, SZ_4);
+
+	of_property_read_u32(sphy->dev->of_node, "samsung,enable-mask",
+							&sphy->en_mask);
+
+	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;
+
+	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 +251,8 @@ 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 +282,8 @@ 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 +305,12 @@ 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 +334,20 @@ static int __devinit samsung_usbphy_probe(struct platform_device *pdev)
 		return PTR_ERR(clk);
 	}
 
-	sphy->dev		= &pdev->dev;
+	sphy->dev = &pdev->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__);
+			return -ENODEV;
+		} else {
+			sphy->plat = pdata;
+		}
+	}
+
 	sphy->plat		= pdata;
 	sphy->regs		= phy_base;
 	sphy->clk		= clk;
-- 
1.7.6.5

[PATCH v2] usb: phy: samsung: Add support to set pmu isolation

[Vivek Gautam]

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'
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
+ * @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", &reg);
+
+		sphy->devctrl_reg = ioremap(reg, SZ_4);
+
+		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;
+
+	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__);
+			return -ENODEV;
+		} else {
+			sphy->plat = pdata;
+		}
+	}
+
 	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;
 }
 
-- 
1.7.6.5

[PATCH v2] usb: phy: samsung: Add support to set pmu isolation

[Sylwester Nawrocki]

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 at 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",&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