[PATCH v3] usb: phy: samsung: Add support to set pmu isolation

Changes from v2:
 - Removed the phandle type of device node properties, instead using
   sub-nodes now.
 - Removed the property 'samsung,enable-mask' since it is SoC dependent
   (SoCs like S5PV210 and S3C64XX have different bits to enable/disable
   phy controller in comparison to exysno4210 onwards).
 - Maintaining the phy enable mask (which is SoC dependent) for device type phy
   and host type phy in the driver data.
 - Re-structuring to get device properties using sub-nodes for 'usbphy-pmu'

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()'.

Based on usb-next branch with Praveen Paneri's patches on top of it.
- http://lists.infradead.org/pipermail/linux-arm-kernel/2012-November/134476.html
- http://lists.infradead.org/pipermail/linux-arm-kernel/2012-November/131763.html

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

 .../devicetree/bindings/usb/samsung-usbphy.txt     |   28 ++++
 drivers/usb/phy/samsung-usbphy.c                   |  145 +++++++++++++++++---
 2 files changed, 152 insertions(+), 21 deletions(-)

-- 
1.7.6.5

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 <redacted>
---
 .../devicetree/bindings/usb/samsung-usbphy.txt     |   28 ++++
 drivers/usb/phy/samsung-usbphy.c                   |  145 +++++++++++++++++---
 2 files changed, 152 insertions(+), 21 deletions(-)

diff --git a/Documentation/devicetree/bindings/usb/samsung-usbphy.txt b/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
index 7b26e2d..09f06f8 100644
--- a/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
+++ b/Documentation/devicetree/bindings/usb/samsung-usbphy.txt

@@ -9,3 +9,31 @@ Required properties:
 - compatible : should be "samsung,exynos4210-usbphy"
 - reg : base physical address of the phy registers and length of memory mapped
 	region.
+- #address-cells: should be 1.
+- #size-cells: should be 0.
+
+Optional properties:
+- The samsung usbphy nodes should provide the following information required
+  by USB-phy controller to enable/disable the phy controller.
+   - reg : base physical address of PHY control register in PMU which
+           enables/disables the phy controller.
+           The size of this register is the total sum of size of all phy-control
+           registers that the SoC has. For example, the size will be
+           '0x4' in case we have only one phy-control register (like in S3C64XX) or
+           '0x8' in case we have two phy-control registers (like in Exynos4210)
+           and so on.
+
+Example:
+ - Exysno4210
+
+	usbphy at 125B0000 {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "samsung,exynos4210-usbphy";
+		reg = <0x125B0000 0x100>;
+
+		usbphy-pmu {
+			/* USB device and host PHY_CONTROL registers */
+			reg = <0x10020704 0x8>;
+		};
+	};

diff --git a/drivers/usb/phy/samsung-usbphy.c b/drivers/usb/phy/samsung-usbphy.c
index 5c5e1bb5..2260029 100644
--- a/drivers/usb/phy/samsung-usbphy.c
+++ b/drivers/usb/phy/samsung-usbphy.c

@@ -60,20 +60,43 @@
 #define MHZ (1000*1000)
 #endif
 
+#define S3C64XX_USBPHY_ENABLE			(0x1 << 16)
+#define EXYNOS_USBPHY_ENABLE			(0x1 << 0)
+
 enum samsung_cpu_type {
 	TYPE_S3C64XX,
 	TYPE_EXYNOS4210,
 };
 
 /*
+ * struct samsung_usbphy_drvdata - driver data for various SoC variants
+ * @cpu_type: machine identifier
+ * @devphy_en_mask: device phy enable mask for PHY CONTROL register
+ * @hostphy_en_mask: host phy enable mask for PHY CONTROL register
+ *
+ *	having different mask for host and device type phy
+ *	helps in setting independent masks in case of SoCs like
+ *	S5PV210 in which PHY0 and PHY1 enable bits belong to same
+ *	register placed at [0] and [1] respectively.
+ *	Although for newer SoCs like exynos these bits belong to
+ *	different registers altogether placed@[0].
+ */
+struct samsung_usbphy_drvdata {
+	int cpu_type;
+	int devphy_en_mask;
+	int hostphy_en_mask;
+};
+
+/*
  * struct samsung_usbphy - transceiver driver state
  * @phy: transceiver structure
  * @plat: platform data
  * @dev: The parent device supplied to the probe function
  * @clk: usb phy clock
  * @regs: usb phy register memory base
+ * @phyctrl_pmureg: usb device phy-control pmu register memory base
  * @ref_clk_freq: reference clock frequency selection
- * @cpu_type: machine identifier
+ * @drv_data: driver data available for different cpu types
  */
 struct samsung_usbphy {
 	struct usb_phy	phy;

@@ -81,12 +104,66 @@ struct samsung_usbphy {
 	struct device	*dev;
 	struct clk	*clk;
 	void __iomem	*regs;
+	void __iomem	*phyctrl_pmureg;
 	int		ref_clk_freq;
-	int		cpu_type;
+	struct samsung_usbphy_drvdata *drv_data;
 };
 
 #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 *usbphy_pmu;
+	u32 reg[2];
+	int ret;
+
+	if (!sphy->dev->of_node) {
+		dev_err(sphy->dev, "Can't get usb-phy node\n");
+		return -ENODEV;
+	}
+
+	usbphy_pmu = of_get_child_by_name(sphy->dev->of_node, "usbphy-pmu");
+	if (!usbphy_pmu)
+		dev_warn(sphy->dev, "Can't get usb-phy pmu control node\n");
+
+	ret = of_property_read_u32_array(usbphy_pmu, "reg", reg, 2);
+	if (!ret)
+		sphy->phyctrl_pmureg = ioremap(reg[0], reg[1]);
+
+	of_node_put(usbphy_pmu);
+
+	if (IS_ERR_OR_NULL(sphy->phyctrl_pmureg)) {
+		dev_err(sphy->dev, "Can't get usb-phy pmu control register\n");
+		return -ENODEV;
+	}
+
+	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)
+{
+	u32 reg;
+	int en_mask;
+
+	if (!sphy->phyctrl_pmureg) {
+		dev_warn(sphy->dev, "Can't set pmu isolation\n");
+		return;
+	}
+
+	reg = readl(sphy->phyctrl_pmureg);
+
+	en_mask = sphy->drv_data->devphy_en_mask;
+
+	if (on)
+		writel(reg & ~en_mask, sphy->phyctrl_pmureg);
+	else
+		writel(reg | en_mask, sphy->phyctrl_pmureg);
+}
+
 /*
  * Returns reference clock frequency selection value
  */

@@ -112,7 +189,7 @@ static int samsung_usbphy_get_refclk_freq(struct samsung_usbphy *sphy)
 		refclk_freq = PHYCLK_CLKSEL_48M;
 		break;
 	default:
-		if (sphy->cpu_type == TYPE_S3C64XX)
+		if (sphy->drv_data->cpu_type == TYPE_S3C64XX)
 			refclk_freq = PHYCLK_CLKSEL_48M;
 		else
 			refclk_freq = PHYCLK_CLKSEL_24M;

@@ -135,7 +212,7 @@ static void samsung_usbphy_enable(struct samsung_usbphy *sphy)
 	phypwr = readl(regs + SAMSUNG_PHYPWR);
 	rstcon = readl(regs + SAMSUNG_RSTCON);
 
-	switch (sphy->cpu_type) {
+	switch (sphy->drv_data->cpu_type) {
 	case TYPE_S3C64XX:
 		phyclk &= ~PHYCLK_COMMON_ON_N;
 		phypwr &= ~PHYPWR_NORMAL_MASK;

@@ -165,7 +242,7 @@ static void samsung_usbphy_disable(struct samsung_usbphy *sphy)
 
 	phypwr = readl(regs + SAMSUNG_PHYPWR);
 
-	switch (sphy->cpu_type) {
+	switch (sphy->drv_data->cpu_type) {
 	case TYPE_S3C64XX:
 		phypwr |= PHYPWR_NORMAL_MASK;
 		break;

@@ -199,6 +276,8 @@ 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);

@@ -228,38 +307,37 @@ 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);
 }
 
 static const struct of_device_id samsung_usbphy_dt_match[];
 
-static inline int samsung_usbphy_get_driver_data(struct platform_device *pdev)
+static inline struct samsung_usbphy_drvdata
+*samsung_usbphy_get_driver_data(struct platform_device *pdev)
 {
 	if (pdev->dev.of_node) {
 		const struct of_device_id *match;
 		match = of_match_node(samsung_usbphy_dt_match,
 							pdev->dev.of_node);
-		return (int) match->data;
+		return (struct samsung_usbphy_drvdata *) match->data;
 	}
 
-	return platform_get_device_id(pdev)->driver_data;
+	return ((struct samsung_usbphy_drvdata *)
+				platform_get_device_id(pdev)->driver_data);
 }
 
 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 +361,19 @@ static int __devinit samsung_usbphy_probe(struct platform_device *pdev)
 		return PTR_ERR(clk);
 	}
 
-	sphy->dev		= &pdev->dev;
+	sphy->dev = dev;
+
+	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;
+		}
+	}
+
 	sphy->plat		= pdata;
 	sphy->regs		= phy_base;
 	sphy->clk		= clk;

@@ -291,7 +381,7 @@ static int __devinit samsung_usbphy_probe(struct platform_device *pdev)
 	sphy->phy.label		= "samsung-usbphy";
 	sphy->phy.init		= samsung_usbphy_init;
 	sphy->phy.shutdown	= samsung_usbphy_shutdown;
-	sphy->cpu_type		= samsung_usbphy_get_driver_data(pdev);
+	sphy->drv_data		= samsung_usbphy_get_driver_data(pdev);
 	sphy->ref_clk_freq	= samsung_usbphy_get_refclk_freq(sphy);
 
 	platform_set_drvdata(pdev, sphy);

@@ -305,17 +395,30 @@ static int __exit samsung_usbphy_remove(struct platform_device *pdev)
 
 	usb_remove_phy(&sphy->phy);
 
+	if (sphy->phyctrl_pmureg)
+		iounmap(sphy->phyctrl_pmureg);
+
 	return 0;
 }
 
+static struct samsung_usbphy_drvdata usbphy_s3c64xx = {
+	.cpu_type		= TYPE_S3C64XX,
+	.devphy_en_mask		= S3C64XX_USBPHY_ENABLE,
+};
+
+static struct samsung_usbphy_drvdata usbphy_exynos4 = {
+	.cpu_type		= TYPE_EXYNOS4210,
+	.devphy_en_mask		= EXYNOS_USBPHY_ENABLE,
+};
+
 #ifdef CONFIG_OF
 static const struct of_device_id samsung_usbphy_dt_match[] = {
 	{
 		.compatible = "samsung,s3c64xx-usbphy",
-		.data = (void *)TYPE_S3C64XX,
+		.data = (void *)&usbphy_s3c64xx,
 	}, {
 		.compatible = "samsung,exynos4210-usbphy",
-		.data = (void *)TYPE_EXYNOS4210,
+		.data = (void *)&usbphy_exynos4,
 	},
 	{},
 };

@@ -325,10 +428,10 @@ MODULE_DEVICE_TABLE(of, samsung_usbphy_dt_match);
 static struct platform_device_id samsung_usbphy_driver_ids[] = {
 	{
 		.name		= "s3c64xx-usbphy",
-		.driver_data	= TYPE_S3C64XX,
+		.driver_data	= (unsigned long)&usbphy_s3c64xx,
 	}, {
 		.name		= "exynos4210-usbphy",
-		.driver_data	= TYPE_EXYNOS4210,
+		.driver_data	= (unsigned long)&usbphy_exynos4,
 	},
 	{},
 };

-- 
1.7.6.5

Vivek,

Nothing really serious below and things look good to me, but figured
I'd put a few nits in (sorry!).


On Fri, Dec 21, 2012 at 12:16 AM, Vivek Gautam [off-list ref] wrote:

Doesn't match your example.  Probably should be 1.

This is really a "devphy_dis_mask", isn't it?  AKA: setting to 1
disables the phy and setting to 0 enables the phy.

+       int hostphy_en_mask;

Code below always uses devphy and only ever inits devphy.  I assume
future code will init / use hostphy?  Worth moving the hostphy part in
that patch?

nit: const

+static int samsung_usbphy_parse_dt_param(struct samsung_usbphy *sphy)
+{
+       struct device_node *usbphy_pmu;
+       u32 reg[2];
+       int ret;
+
+       if (!sphy->dev->of_node) {
+               dev_err(sphy->dev, "Can't get usb-phy node\n");
+               return -ENODEV;
+       }
+
+       usbphy_pmu = of_get_child_by_name(sphy->dev->of_node, "usbphy-pmu");
+       if (!usbphy_pmu)
+               dev_warn(sphy->dev, "Can't get usb-phy pmu control node\n");
+
+       ret = of_property_read_u32_array(usbphy_pmu, "reg", reg, 2);

nit: use ARRAY_SIZE(reg)

+       if (!ret)
+               sphy->phyctrl_pmureg = ioremap(reg[0], reg[1]);
+
+       of_node_put(usbphy_pmu);
+
+       if (IS_ERR_OR_NULL(sphy->phyctrl_pmureg)) {
+               dev_err(sphy->dev, "Can't get usb-phy pmu control register\n");

I don't think there's any cases where it matters (you'll error out of
the driver if you return an error here), but seems like it might be
nice to set sphy->phyctrl_pmureg to NULL here since other places test
this member against NULL only.

+static inline struct samsung_usbphy_drvdata
+*samsung_usbphy_get_driver_data(struct platform_device *pdev)
 {
        if (pdev->dev.of_node) {
                const struct of_device_id *match;
                match = of_match_node(samsung_usbphy_dt_match,
                                                        pdev->dev.of_node);
-               return (int) match->data;
+               return (struct samsung_usbphy_drvdata *) match->data;

nit: no need for a cast here, I believe.

        }

-       return platform_get_device_id(pdev)->driver_data;
+       return ((struct samsung_usbphy_drvdata *)
+                               platform_get_device_id(pdev)->driver_data);

nit: no need for a cast here, I believe.

+static struct samsung_usbphy_drvdata usbphy_s3c64xx = {
+       .cpu_type               = TYPE_S3C64XX,
+       .devphy_en_mask         = S3C64XX_USBPHY_ENABLE,
+};
+
+static struct samsung_usbphy_drvdata usbphy_exynos4 = {
+       .cpu_type               = TYPE_EXYNOS4210,
+       .devphy_en_mask         = EXYNOS_USBPHY_ENABLE,
+};
+

nit: static const for these structs?



-Doug

Hi Doug,


On Fri, Dec 21, 2012 at 10:35 PM, Doug Anderson [off-list ref] wrote:

Vivek,

Nothing really serious below and things look good to me, but figured
I'd put a few nits in (sorry!).


On Fri, Dec 21, 2012 at 12:16 AM, Vivek Gautam [off-list ref] wrote:

quoted

diff --git a/Documentation/devicetree/bindings/usb/samsung-usbphy.txt b/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
index 7b26e2d..09f06f8 100644
--- a/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
+++ b/Documentation/devicetree/bindings/usb/samsung-usbphy.txt

@@ -9,3 +9,31 @@ Required properties:
 - compatible : should be "samsung,exynos4210-usbphy"
 - reg : base physical address of the phy registers and length of memory mapped
        region.
+- #address-cells: should be 1.
+- #size-cells: should be 0.

Doesn't match your example.  Probably should be 1.

Oops !! true it is 1, will amend this.

quoted

diff --git a/drivers/usb/phy/samsung-usbphy.c b/drivers/usb/phy/samsung-usbphy.c
index 5c5e1bb5..2260029 100644
--- a/drivers/usb/phy/samsung-usbphy.c
+++ b/drivers/usb/phy/samsung-usbphy.c
 /*
+ * struct samsung_usbphy_drvdata - driver data for various SoC variants
+ * @cpu_type: machine identifier
+ * @devphy_en_mask: device phy enable mask for PHY CONTROL register
+ * @hostphy_en_mask: host phy enable mask for PHY CONTROL register
+ *
+ *     having different mask for host and device type phy
+ *     helps in setting independent masks in case of SoCs like
+ *     S5PV210 in which PHY0 and PHY1 enable bits belong to same
+ *     register placed at [0] and [1] respectively.
+ *     Although for newer SoCs like exynos these bits belong to
+ *     different registers altogether placed at [0].
+ */
+struct samsung_usbphy_drvdata {
+       int cpu_type;
+       int devphy_en_mask;

This is really a "devphy_dis_mask", isn't it?  AKA: setting to 1
disables the phy and setting to 0 enables the phy.

This is actually 'devphy_en_mask' only. We use it this way:
When pmu_isolation is true, meaning usbphy is isolated from pmu
so we are resetting this bit to disable usbphy, as there in
samsung_usbphy_set_isolation().

quoted

+       int hostphy_en_mask;

Code below always uses devphy and only ever inits devphy.  I assume
future code will init / use hostphy?  Worth moving the hostphy part in
that patch?

Sure will move this in forthcoming  patch for host phy.

quoted

 struct samsung_usbphy {
        struct usb_phy  phy;

@@ -81,12 +104,66 @@ struct samsung_usbphy {
        struct device   *dev;
        struct clk      *clk;
        void __iomem    *regs;
+       void __iomem    *phyctrl_pmureg;
        int             ref_clk_freq;
-       int             cpu_type;
+       struct samsung_usbphy_drvdata *drv_data;

nit: const

Will make it const.

quoted

+static int samsung_usbphy_parse_dt_param(struct samsung_usbphy *sphy)
+{
+       struct device_node *usbphy_pmu;
+       u32 reg[2];
+       int ret;
+
+       if (!sphy->dev->of_node) {
+               dev_err(sphy->dev, "Can't get usb-phy node\n");
+               return -ENODEV;
+       }
+
+       usbphy_pmu = of_get_child_by_name(sphy->dev->of_node, "usbphy-pmu");
+       if (!usbphy_pmu)
+               dev_warn(sphy->dev, "Can't get usb-phy pmu control node\n");
+
+       ret = of_property_read_u32_array(usbphy_pmu, "reg", reg, 2);

nit: use ARRAY_SIZE(reg)

Sure will amend this.

quoted

+       if (!ret)
+               sphy->phyctrl_pmureg = ioremap(reg[0], reg[1]);
+
+       of_node_put(usbphy_pmu);
+
+       if (IS_ERR_OR_NULL(sphy->phyctrl_pmureg)) {
+               dev_err(sphy->dev, "Can't get usb-phy pmu control register\n");

I don't think there's any cases where it matters (you'll error out of
the driver if you return an error here), but seems like it might be
nice to set sphy->phyctrl_pmureg to NULL here since other places test
this member against NULL only.

Isn't devm_kzallocing the memory for sphy setting sphy->phyctrl_pmureg to NULL ?
Then, does checking here for IS_ERR_OR_NULL(sphy->phyctrl_pmureg) has
a problem ?
Probably i am not getting what is expected here. :-(

quoted

+static inline struct samsung_usbphy_drvdata
+*samsung_usbphy_get_driver_data(struct platform_device *pdev)
 {
        if (pdev->dev.of_node) {
                const struct of_device_id *match;
                match = of_match_node(samsung_usbphy_dt_match,
                                                        pdev->dev.of_node);
-               return (int) match->data;
+               return (struct samsung_usbphy_drvdata *) match->data;

nit: no need for a cast here, I believe.

"samsung_usbphy_get_driver_data()" is returning (struct
samsung_usbphy_drvdata *)
and the data is actually (void *). So won't we need a cast here.
I am actually getting compile time warnings.

quoted

        }

-       return platform_get_device_id(pdev)->driver_data;
+       return ((struct samsung_usbphy_drvdata *)
+                               platform_get_device_id(pdev)->driver_data);

nit: no need for a cast here, I believe.

ditto here, the driver data for non dt is (unsigned long). So ?

quoted

+static struct samsung_usbphy_drvdata usbphy_s3c64xx = {
+       .cpu_type               = TYPE_S3C64XX,
+       .devphy_en_mask         = S3C64XX_USBPHY_ENABLE,
+};
+
+static struct samsung_usbphy_drvdata usbphy_exynos4 = {
+       .cpu_type               = TYPE_EXYNOS4210,
+       .devphy_en_mask         = EXYNOS_USBPHY_ENABLE,
+};
+

nit: static const for these structs?

Sure will make them const. no harm.

-Doug
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-- 
Thanks & Regards
Vivek