Patchwork [v5,3/4] usb: ohci-exynos: Add facility to use phy provided by the generic phy framework

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Submitter Vivek Gautam
Date May 2, 2014, 12:47 p.m.
Message ID <1399034855-9686-4-git-send-email-gautam.vivek@samsung.com>
Download mbox | patch
Permalink /patch/344951/
State New
Headers show

Comments

Vivek Gautam - May 2, 2014, 12:47 p.m.
Add support to consume phy provided by Generic phy framework.
Keeping the support for older usb-phy intact right now, in order
to prevent any functionality break in absence of relevant
device tree side change for ohci-exynos.
Once we move to new phy in the device nodes for ohci, we can
remove the support for older phys.

Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
---

Changes from v4:
 - Removed 'phy-names' property from the bindings since we don't need it.
 - Restructured exynos_ohci_get_phy() function to handle error codes as
   well as return relevant error codes effectively.
 - Added IS_ERR() check for PHYs in exynos_ohci_phy_enable()/disable().

Changes from v3:
 - Calling usb_phy_shutdown() when exynos_ohci_phy_enable() is failing.
 - Made exynos_ohci_phy_disable() return void, since its return value
   did not serve any purpose.
 - Calling clk_disable_unprepare() in exynos_ohci_resume() when
   exynos_ohci_phy_enable() is failed.

 .../devicetree/bindings/usb/exynos-usb.txt         |   16 +++
 drivers/usb/host/ohci-exynos.c                     |  120 +++++++++++++++++---
 2 files changed, 120 insertions(+), 16 deletions(-)
Tomasz Figa - May 2, 2014, 5:39 p.m.
Hi Vivek,

This looks much better, but there still are some issues. Please see my 
comments inline.

On 02.05.2014 14:47, Vivek Gautam wrote:
> Add support to consume phy provided by Generic phy framework.
> Keeping the support for older usb-phy intact right now, in order
> to prevent any functionality break in absence of relevant
> device tree side change for ohci-exynos.
> Once we move to new phy in the device nodes for ohci, we can
> remove the support for older phys.
>
> Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
> Cc: Jingoo Han <jg1.han@samsung.com>
> Acked-by: Alan Stern <stern@rowland.harvard.edu>
> ---
>
> Changes from v4:
>   - Removed 'phy-names' property from the bindings since we don't need it.
>   - Restructured exynos_ohci_get_phy() function to handle error codes as
>     well as return relevant error codes effectively.
>   - Added IS_ERR() check for PHYs in exynos_ohci_phy_enable()/disable().
>
> Changes from v3:
>   - Calling usb_phy_shutdown() when exynos_ohci_phy_enable() is failing.
>   - Made exynos_ohci_phy_disable() return void, since its return value
>     did not serve any purpose.
>   - Calling clk_disable_unprepare() in exynos_ohci_resume() when
>     exynos_ohci_phy_enable() is failed.
>
>   .../devicetree/bindings/usb/exynos-usb.txt         |   16 +++
>   drivers/usb/host/ohci-exynos.c                     |  120 +++++++++++++++++---
>   2 files changed, 120 insertions(+), 16 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/usb/exynos-usb.txt b/Documentation/devicetree/bindings/usb/exynos-usb.txt
> index d967ba1..49a9c6f 100644
> --- a/Documentation/devicetree/bindings/usb/exynos-usb.txt
> +++ b/Documentation/devicetree/bindings/usb/exynos-usb.txt
> @@ -38,6 +38,13 @@ Required properties:
>    - interrupts: interrupt number to the cpu.
>    - clocks: from common clock binding: handle to usb clock.
>    - clock-names: from common clock binding: Shall be "usbhost".
> + - port: if in the SoC there are OHCI phys, they should be listed here.
> +   One phy per port. Each port should have following entries:
> +	- reg: port number on OHCI controller, e.g
> +	       On Exynos5250, port 0 is USB2.0 otg phy
> +			      port 1 is HSIC phy0
> +			      port 2 is HSIC phy1
> +	- phys: from the *Generic PHY* bindings, specifying phy used by port.
>
>   Example:
>   	usb@12120000 {
> @@ -47,6 +54,15 @@ Example:
>
>   		clocks = <&clock 285>;
>   		clock-names = "usbhost";
> +
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +		port@0 {
> +		    reg = <0>;
> +		    phys = <&usb2phy 1>;
> +		    status = "disabled";
> +		};
> +
>   	};
>
>   DWC3
> diff --git a/drivers/usb/host/ohci-exynos.c b/drivers/usb/host/ohci-exynos.c
> index 05f00e3..e66d391 100644
> --- a/drivers/usb/host/ohci-exynos.c
> +++ b/drivers/usb/host/ohci-exynos.c
> @@ -18,6 +18,7 @@
>   #include <linux/module.h>
>   #include <linux/of.h>
>   #include <linux/platform_device.h>
> +#include <linux/phy/phy.h>
>   #include <linux/usb/phy.h>
>   #include <linux/usb/samsung_usb_phy.h>
>   #include <linux/usb.h>
> @@ -33,28 +34,112 @@ static struct hc_driver __read_mostly exynos_ohci_hc_driver;
>
>   #define to_exynos_ohci(hcd) (struct exynos_ohci_hcd *)(hcd_to_ohci(hcd)->priv)
>
> +#define PHY_NUMBER 3
> +
>   struct exynos_ohci_hcd {
>   	struct clk *clk;
>   	struct usb_phy *phy;
>   	struct usb_otg *otg;
> +	struct phy *phy_g[PHY_NUMBER];
>   };
>
> -static void exynos_ohci_phy_enable(struct device *dev)
> +static int exynos_ohci_get_phy(struct device *dev,
> +				struct exynos_ohci_hcd *exynos_ohci)
> +{
> +	struct device_node *child;
> +	struct phy *phy;
> +	int phy_number;
> +	int ret = 0;
> +
> +	exynos_ohci->phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2);
> +	if (IS_ERR(exynos_ohci->phy)) {
> +		ret = PTR_ERR(exynos_ohci->phy);
> +		if (ret != -ENXIO && ret != -ENODEV) {
> +			dev_err(dev, "no usb2 phy configured\n");
> +			return ret;
> +		}
> +		dev_dbg(dev, "Failed to get usb2 phy\n");
> +		exynos_ohci->phy = ERR_PTR(-ENODEV);

Here you already have exynos_ohci->phy set to an ERR_PTR() value, which 
was returned by devm_usb_get_phy(). There is no need to overwrite it.

> +	} else {
> +		exynos_ohci->otg = exynos_ohci->phy->otg;
> +	}
> +
> +	/*
> +	 * Getting generic phy:
> +	 * We are keeping both types of phys as a part of transiting OHCI
> +	 * to generic phy framework, so as to maintain backward compatibilty
> +	 * with old DTB.
> +	 * If there are existing devices using DTB files built from them,
> +	 * to remove the support for old bindings in this driver,
> +	 * we need to make sure that such devices have their DTBs
> +	 * updated to ones built from new DTS.
> +	 */
> +	for_each_available_child_of_node(dev->of_node, child) {
> +		ret = of_property_read_u32(child, "reg", &phy_number);
> +		if (ret) {
> +			dev_err(dev, "Failed to parse device tree\n");
> +			of_node_put(child);
> +			return ret;
> +		}
> +
> +		if (phy_number >= PHY_NUMBER) {
> +			dev_err(dev, "Invalid number of PHYs\n");
> +			of_node_put(child);
> +			return -EINVAL;
> +		}
> +
> +		phy = devm_of_phy_get(dev, child, 0);
> +		of_node_put(child);
> +		if (IS_ERR(phy)) {
> +			ret = PTR_ERR(phy);
> +			if (ret != -ENXIO && ret != -ENODEV) {

Shouldn't this be -ENOSYS instead of -ENXIO? At least this is the error 
code I can see in the stubs provided in include/linux/phy/phy.h.

> +				dev_err(dev, "no usb2 phy configured\n");
> +				return ret;
> +			}
> +			dev_dbg(dev, "Failed to get usb2 phy\n");
> +			phy = ERR_PTR(-ENODEV);

phy is already an ERR_PTR() here, as returned by devm_of_phy_get().

I guess the same comments apply to patch 4/4.

Best regards,
Tomasz
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Patch

diff --git a/Documentation/devicetree/bindings/usb/exynos-usb.txt b/Documentation/devicetree/bindings/usb/exynos-usb.txt
index d967ba1..49a9c6f 100644
--- a/Documentation/devicetree/bindings/usb/exynos-usb.txt
+++ b/Documentation/devicetree/bindings/usb/exynos-usb.txt
@@ -38,6 +38,13 @@  Required properties:
  - interrupts: interrupt number to the cpu.
  - clocks: from common clock binding: handle to usb clock.
  - clock-names: from common clock binding: Shall be "usbhost".
+ - port: if in the SoC there are OHCI phys, they should be listed here.
+   One phy per port. Each port should have following entries:
+	- reg: port number on OHCI controller, e.g
+	       On Exynos5250, port 0 is USB2.0 otg phy
+			      port 1 is HSIC phy0
+			      port 2 is HSIC phy1
+	- phys: from the *Generic PHY* bindings, specifying phy used by port.
 
 Example:
 	usb@12120000 {
@@ -47,6 +54,15 @@  Example:
 
 		clocks = <&clock 285>;
 		clock-names = "usbhost";
+
+		#address-cells = <1>;
+		#size-cells = <0>;
+		port@0 {
+		    reg = <0>;
+		    phys = <&usb2phy 1>;
+		    status = "disabled";
+		};
+
 	};
 
 DWC3
diff --git a/drivers/usb/host/ohci-exynos.c b/drivers/usb/host/ohci-exynos.c
index 05f00e3..e66d391 100644
--- a/drivers/usb/host/ohci-exynos.c
+++ b/drivers/usb/host/ohci-exynos.c
@@ -18,6 +18,7 @@ 
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/phy/phy.h>
 #include <linux/usb/phy.h>
 #include <linux/usb/samsung_usb_phy.h>
 #include <linux/usb.h>
@@ -33,28 +34,112 @@  static struct hc_driver __read_mostly exynos_ohci_hc_driver;
 
 #define to_exynos_ohci(hcd) (struct exynos_ohci_hcd *)(hcd_to_ohci(hcd)->priv)
 
+#define PHY_NUMBER 3
+
 struct exynos_ohci_hcd {
 	struct clk *clk;
 	struct usb_phy *phy;
 	struct usb_otg *otg;
+	struct phy *phy_g[PHY_NUMBER];
 };
 
-static void exynos_ohci_phy_enable(struct device *dev)
+static int exynos_ohci_get_phy(struct device *dev,
+				struct exynos_ohci_hcd *exynos_ohci)
+{
+	struct device_node *child;
+	struct phy *phy;
+	int phy_number;
+	int ret = 0;
+
+	exynos_ohci->phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2);
+	if (IS_ERR(exynos_ohci->phy)) {
+		ret = PTR_ERR(exynos_ohci->phy);
+		if (ret != -ENXIO && ret != -ENODEV) {
+			dev_err(dev, "no usb2 phy configured\n");
+			return ret;
+		}
+		dev_dbg(dev, "Failed to get usb2 phy\n");
+		exynos_ohci->phy = ERR_PTR(-ENODEV);
+	} else {
+		exynos_ohci->otg = exynos_ohci->phy->otg;
+	}
+
+	/*
+	 * Getting generic phy:
+	 * We are keeping both types of phys as a part of transiting OHCI
+	 * to generic phy framework, so as to maintain backward compatibilty
+	 * with old DTB.
+	 * If there are existing devices using DTB files built from them,
+	 * to remove the support for old bindings in this driver,
+	 * we need to make sure that such devices have their DTBs
+	 * updated to ones built from new DTS.
+	 */
+	for_each_available_child_of_node(dev->of_node, child) {
+		ret = of_property_read_u32(child, "reg", &phy_number);
+		if (ret) {
+			dev_err(dev, "Failed to parse device tree\n");
+			of_node_put(child);
+			return ret;
+		}
+
+		if (phy_number >= PHY_NUMBER) {
+			dev_err(dev, "Invalid number of PHYs\n");
+			of_node_put(child);
+			return -EINVAL;
+		}
+
+		phy = devm_of_phy_get(dev, child, 0);
+		of_node_put(child);
+		if (IS_ERR(phy)) {
+			ret = PTR_ERR(phy);
+			if (ret != -ENXIO && ret != -ENODEV) {
+				dev_err(dev, "no usb2 phy configured\n");
+				return ret;
+			}
+			dev_dbg(dev, "Failed to get usb2 phy\n");
+			phy = ERR_PTR(-ENODEV);
+		}
+		exynos_ohci->phy_g[phy_number] = phy;
+	}
+
+	return ret;
+}
+
+static int exynos_ohci_phy_enable(struct device *dev)
 {
 	struct usb_hcd *hcd = dev_get_drvdata(dev);
 	struct exynos_ohci_hcd *exynos_ohci = to_exynos_ohci(hcd);
+	int i;
+	int ret = 0;
+
+	if (!IS_ERR(exynos_ohci->phy))
+		return usb_phy_init(exynos_ohci->phy);
 
-	if (exynos_ohci->phy)
-		usb_phy_init(exynos_ohci->phy);
+	for (i = 0; ret == 0 && i < PHY_NUMBER; i++)
+		if (!IS_ERR(exynos_ohci->phy_g[i]))
+			ret = phy_power_on(exynos_ohci->phy_g[i]);
+	if (ret)
+		for (i--; i >= 0; i--)
+			if (!IS_ERR(exynos_ohci->phy_g[i]))
+				phy_power_off(exynos_ohci->phy_g[i]);
+
+	return ret;
 }
 
 static void exynos_ohci_phy_disable(struct device *dev)
 {
 	struct usb_hcd *hcd = dev_get_drvdata(dev);
 	struct exynos_ohci_hcd *exynos_ohci = to_exynos_ohci(hcd);
+	int i;
 
-	if (exynos_ohci->phy)
+	if (!IS_ERR(exynos_ohci->phy)) {
 		usb_phy_shutdown(exynos_ohci->phy);
+		return;
+	}
+
+	for (i = 0; i < PHY_NUMBER; i++)
+		if (!IS_ERR(exynos_ohci->phy_g[i]))
+			phy_power_off(exynos_ohci->phy_g[i]);
 }
 
 static int exynos_ohci_probe(struct platform_device *pdev)
@@ -62,7 +147,6 @@  static int exynos_ohci_probe(struct platform_device *pdev)
 	struct exynos_ohci_hcd *exynos_ohci;
 	struct usb_hcd *hcd;
 	struct resource *res;
-	struct usb_phy *phy;
 	int irq;
 	int err;
 
@@ -88,15 +172,9 @@  static int exynos_ohci_probe(struct platform_device *pdev)
 					"samsung,exynos5440-ohci"))
 		goto skip_phy;
 
-	phy = devm_usb_get_phy(&pdev->dev, USB_PHY_TYPE_USB2);
-	if (IS_ERR(phy)) {
-		usb_put_hcd(hcd);
-		dev_warn(&pdev->dev, "no platform data or transceiver defined\n");
-		return -EPROBE_DEFER;
-	} else {
-		exynos_ohci->phy = phy;
-		exynos_ohci->otg = phy->otg;
-	}
+	err = exynos_ohci_get_phy(&pdev->dev, exynos_ohci);
+	if (err)
+		goto fail_clk;
 
 skip_phy:
 	exynos_ohci->clk = devm_clk_get(&pdev->dev, "usbhost");
@@ -139,7 +217,11 @@  skip_phy:
 
 	platform_set_drvdata(pdev, hcd);
 
-	exynos_ohci_phy_enable(&pdev->dev);
+	err = exynos_ohci_phy_enable(&pdev->dev);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to enable USB phy\n");
+		goto fail_io;
+	}
 
 	err = usb_add_hcd(hcd, irq, IRQF_SHARED);
 	if (err) {
@@ -210,13 +292,19 @@  static int exynos_ohci_resume(struct device *dev)
 {
 	struct usb_hcd *hcd			= dev_get_drvdata(dev);
 	struct exynos_ohci_hcd *exynos_ohci	= to_exynos_ohci(hcd);
+	int ret;
 
 	clk_prepare_enable(exynos_ohci->clk);
 
 	if (exynos_ohci->otg)
 		exynos_ohci->otg->set_host(exynos_ohci->otg, &hcd->self);
 
-	exynos_ohci_phy_enable(dev);
+	ret = exynos_ohci_phy_enable(dev);
+	if (ret) {
+		dev_err(dev, "Failed to enable USB phy\n");
+		clk_disable_unprepare(exynos_ohci->clk);
+		return ret;
+	}
 
 	ohci_resume(hcd, false);