ohci and ehci-platform clks, phy and dt support

Add support for ohci-platform instantiation from devicetree, including optionally getting clks and a phy from devicetree, and enabling / disabling those on power_on / off.

This should allow using ohci-platform from devicetree in various cases. Specifically after this commit it can be used for the ohci controller found on Allwinner sunxi SoCs.

Quoted 7 lines · Hans de Goede

Add support for ohci-platform instantiation from devicetree, including optionally getting clks and a phy from devicetree, and enabling / disabling those on power_on / off.

This should allow using ohci-platform from devicetree in various cases. Specifically after this commit it can be used for the ohci controller found on Allwinner sunxi SoCs.

This is fine as far as I am concerned, except for one thing.

drivers/usb/host/ohci-platform.c static int ohci_platform_probe(struct platform_device *dev) · line 131

Quoted 13 lines

drivers/usb/host/ohci-platform.c +2 -7

@@ -60,17 +127,23 @@ static int ohci_platform_probe(struct platform_device *dev)
  	struct usb_hcd *hcd;
  	struct resource *res_mem;
  	struct usb_ohci_pdata *pdata = dev_get_platdata(&dev->dev);
-	int irq;
-	int err = -ENOMEM;
-
-	if (!pdata) {
-		WARN_ON(1);
-		return -ENODEV;
-	}
+	struct ohci_platform_priv *priv;
+	int clk, irq, err;

clk isn't initialized to anything...

drivers/usb/host/ohci-platform.c static int ohci_platform_probe(struct platform_device *dev) · line 214

Quoted 9 lines

drivers/usb/host/ohci-platform.c +3 -2

-err_put_hcd:
-	usb_put_hcd(hcd);
  err_power:
  	if (pdata->power_off)
  		pdata->power_off(dev);
+err_put_clks:
+	while (--clk >= 0)
+		clk_put(priv->clks[clk]);

... but it gets used here. The compiler should have warned about this.

After fixing that, you can add

Acked-by Alan Stern <[email protected]>

Currently ehci-platform is only used in combination with devicetree when used with some Via socs. By extending it to (optionally) get clks and a phy from devicetree, and enabling / disabling those on power_on / off, it can be used more generically. Specifically after this commit it can be used for the ehci controller on Allwinner sunxi SoCs.

Since ehci-platform is intended to handle any generic enough non pci ehci device, add a "usb-ehci" compatibility string.

There already is a usb-ehci device-tree bindings document, update this with clks and phy bindings info.

Although actually quite generic so far the via,vt8500 compatibilty string had its own bindings document. Somehow we even ended up with 2 of them. Since these provide no extra information over the generic usb-ehci documentation, this patch removes them.

The ehci-ppc-of.c driver also claims the usb-ehci compatibility string, even though it mostly is ibm,usb-ehci-440epx specific. ehci-platform.c is not needed on ppc platforms, so add a !PPC_OF dependency to it to avoid 2 drivers claiming the same compatibility string getting build on ppc.

Signed-off-by Hans de Goede <[email protected]>

---
  Documentation/devicetree/bindings/usb/usb-ehci.txt |  25 +++-
  .../devicetree/bindings/usb/via,vt8500-ehci.txt    |  15 ---
  .../devicetree/bindings/usb/vt8500-ehci.txt        |  12 --
  drivers/usb/host/Kconfig                           |   1 +
  drivers/usb/host/ehci-platform.c                   | 149 +++++++++++++++++----
  5 files changed, 142 insertions(+), 60 deletions(-)

delete mode 100644 Documentation/devicetree/bindings/usb/via,vt8500-ehci.txt delete mode 100644 Documentation/devicetree/bindings/usb/vt8500-ehci.txt

Documentation/devicetree/bindings/usb/usb-ehci.txt +18 -7

index fa18612..fad10f3 100644
@@ -7,13 +7,14 @@ Required properties:
      (debug-port or other) can be also specified here, but only after
      definition of standard EHCI registers.
    - interrupts : one EHCI interrupt should be described here.
-If device registers are implemented in big endian mode, the device
-node should have "big-endian-regs" property.
-If controller implementation operates with big endian descriptors,
-"big-endian-desc" property should be specified.
-If both big endian registers and descriptors are used by the controller
-implementation, "big-endian" property can be specified instead of having
-both "big-endian-regs" and "big-endian-desc".
+
+Optional properties:
+ - big-endian-regs : boolean, set this for hcds with big-endian registers
+ - big-endian-desc : boolean, set this for hcds with big-endian descriptors
+ - big-endian : boolean, for hcds with big-endian-regs + big-endian-desc
+ - clocks : a list of phandle + clock specifier pairs
+ - phys : phandle + phy specifier pair
+ - phy-names : "usb"
 
  Example (Sequoia 440EPx):
      ehci at e0000300 {

@@ -23,3 +24,13 @@ Example (Sequoia 440EPx):
  	   reg = <0 e0000300 90 0 e0000390 70>;
  	   big-endian;
     };
+
+Example (Allwinner sun4i A10 SoC):
+   ehci0: ehci at 0x01c14000 {
+	   compatible = "allwinner,sun4i-a10-ehci", "usb-ehci";
+	   reg = <0x01c14000 0x100>;
+	   interrupts = <39>;
+	   clocks = <&ahb_gates 1>;
+	   phys = <&usbphy 1>;
+	   phy-names = "usb";
+   };

Documentation/devicetree/bindings/usb/via,vt8500-ehci.txt deleted +0 -15

deleted file mode 100644
index 17b3ad1..0000000
@@ -1,15 +0,0 @@
-VIA/Wondermedia VT8500 EHCI Controller
------------------------------------------------------
-
-Required properties:
-- compatible : "via,vt8500-ehci"
-- reg : Should contain 1 register ranges(address and length)
-- interrupts : ehci controller interrupt
-
-Example:
-
-	ehci at d8007900 {
-		compatible = "via,vt8500-ehci";
-		reg = <0xd8007900 0x200>;
-		interrupts = <43>;
-	};

Documentation/devicetree/bindings/usb/vt8500-ehci.txt deleted +0 -12

deleted file mode 100644
index 5fb8fd6..0000000
@@ -1,12 +0,0 @@
-VIA VT8500 and Wondermedia WM8xxx SoC USB controllers.
-
-Required properties:
- - compatible: Should be "via,vt8500-ehci" or "wm,prizm-ehci".
- - reg: Address range of the ehci registers. size should be 0x200
- - interrupts: Should contain the ehci interrupt.
-
-usb: ehci at D8007100 {
-	compatible = "wm,prizm-ehci", "usb-ehci";
-	reg = <0xD8007100 0x200>;
-	interrupts = <1>;
-};

drivers/usb/host/Kconfig +1 -0

index a9707da..e28cbe0 100644
@@ -255,6 +255,7 @@ config USB_EHCI_ATH79
 
  config USB_EHCI_HCD_PLATFORM
  	tristate "Generic EHCI driver for a platform device"
+	depends on !PPC_OF
  	default n
  	---help---
  	  Adds an EHCI host driver for a generic platform device, which

drivers/usb/host/ehci-platform.c +121 -26

index 7f30b71..5c4f892 100644
@@ -3,6 +3,7 @@
   *
   * Copyright 2007 Steven Brown <[email protected]>
   * Copyright 2010-2012 Hauke Mehrtens <[email protected]>
+ * Copyright 2014 Hans de Goede <[email protected]>
   *
   * Derived from the ohci-ssb driver
   * Copyright 2007 Michael Buesch <[email protected]>

@@ -18,6 +19,7 @@
   *
   * Licensed under the GNU/GPL. See COPYING for details.
   */
+#include <linux/clk.h>
  #include <linux/dma-mapping.h>
  #include <linux/err.h>
  #include <linux/kernel.h>

@@ -25,6 +27,7 @@
  #include <linux/io.h>
  #include <linux/module.h>
  #include <linux/of.h>
+#include <linux/phy/phy.h>
  #include <linux/platform_device.h>
  #include <linux/usb.h>
  #include <linux/usb/hcd.h>

@@ -33,6 +36,13 @@
  #include "ehci.h"
 
  #define DRIVER_DESC "EHCI generic platform driver"
+#define EHCI_MAX_CLKS 3
+#define hcd_to_ehci_priv(h) ((struct ehci_platform_priv *)hcd_to_ehci(h)->priv)
+
+struct ehci_platform_priv {
+	struct clk *clks[EHCI_MAX_CLKS];
+	struct phy *phy;
+};
 
  static const char hcd_name[] = "ehci-platform";
 

@@ -64,38 +74,90 @@ static int ehci_platform_reset(struct usb_hcd *hcd)
  	return 0;
  }
 
+static int ehci_platform_power_on(struct platform_device *dev)
+{
+	struct usb_hcd *hcd = platform_get_drvdata(dev);
+	struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
+	int clk, ret;
+
+	for (clk = 0; priv->clks[clk] && clk < EHCI_MAX_CLKS; clk++) {
+		ret = clk_prepare_enable(priv->clks[clk]);
+		if (ret)
+			goto err_disable_clks;
+	}
+
+	if (priv->phy) {
+		ret = phy_init(priv->phy);
+		if (ret)
+			goto err_disable_clks;
+
+		ret = phy_power_on(priv->phy);
+		if (ret)
+			goto err_exit_phy;
+	}
+
+	return 0;
+
+err_exit_phy:
+	phy_exit(priv->phy);
+err_disable_clks:
+	while (--clk >= 0)
+		clk_disable_unprepare(priv->clks[clk]);
+
+	return ret;
+}
+
+static void ehci_platform_power_off(struct platform_device *dev)
+{
+	struct usb_hcd *hcd = platform_get_drvdata(dev);
+	struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
+	int clk;
+
+	if (priv->phy) {
+		phy_power_off(priv->phy);
+		phy_exit(priv->phy);
+	}
+
+	for (clk = EHCI_MAX_CLKS - 1; clk >= 0; clk--)
+		if (priv->clks[clk])
+			clk_disable_unprepare(priv->clks[clk]);
+}
+
  static struct hc_driver __read_mostly ehci_platform_hc_driver;
 
  static const struct ehci_driver_overrides platform_overrides __initconst = {
-	.reset =	ehci_platform_reset,
+	.reset =		ehci_platform_reset,
+	.extra_priv_size =	sizeof(struct ehci_platform_priv),
  };
 
-static struct usb_ehci_pdata ehci_platform_defaults;
+static struct usb_ehci_pdata ehci_platform_defaults = {
+	.power_on =		ehci_platform_power_on,
+	.power_suspend =	ehci_platform_power_off,
+	.power_off =		ehci_platform_power_off,
+};
 
  static int ehci_platform_probe(struct platform_device *dev)
  {
  	struct usb_hcd *hcd;
  	struct resource *res_mem;
-	struct usb_ehci_pdata *pdata;
-	int irq;
-	int err;
+	struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
+	struct ehci_platform_priv *priv;
+	int clk, irq, err;
 
  	if (usb_disabled())
  		return -ENODEV;
 
  	/*
-	 * use reasonable defaults so platforms don't have to provide these.
-	 * with DT probing on ARM, none of these are set.
+	 * Use reasonable defaults so platforms don't have to provide these
+	 * with DT probing on ARM.
  	 */
-	if (!dev_get_platdata(&dev->dev))
-		dev->dev.platform_data = &ehci_platform_defaults;
+	if (!pdata)
+		pdata = &ehci_platform_defaults;
 
  	err = dma_coerce_mask_and_coherent(&dev->dev, DMA_BIT_MASK(32));
  	if (err)
  		return err;
 
-	pdata = dev_get_platdata(&dev->dev);
-
  	irq = platform_get_irq(dev, 0);
  	if (irq < 0) {
  		dev_err(&dev->dev, "no irq provided");

@@ -107,17 +169,40 @@ static int ehci_platform_probe(struct platform_device *dev)
  		return -ENXIO;
  	}
 
+	hcd = usb_create_hcd(&ehci_platform_hc_driver, &dev->dev,
+			     dev_name(&dev->dev));
+	if (!hcd)
+		return -ENOMEM;
+
+	platform_set_drvdata(dev, hcd);
+	dev->dev.platform_data = pdata;
+	priv = hcd_to_ehci_priv(hcd);
+
+	if (pdata == &ehci_platform_defaults && dev->dev.of_node) {
+		priv->phy = devm_phy_get(&dev->dev, "usb");
+		if (IS_ERR(priv->phy)) {
+			err = PTR_ERR(priv->phy);
+			if (err == -EPROBE_DEFER)
+				goto err_put_hcd;
+			priv->phy = NULL;
+		}
+
+		for (clk = 0; clk < EHCI_MAX_CLKS; clk++) {
+			priv->clks[clk] = of_clk_get(dev->dev.of_node, clk);
+			if (IS_ERR(priv->clks[clk])) {
+				err = PTR_ERR(priv->clks[clk]);
+				if (err == -EPROBE_DEFER)
+					goto err_put_clks;
+				priv->clks[clk] = NULL;
+				break;
+			}
+		}
+	}
+
  	if (pdata->power_on) {
  		err = pdata->power_on(dev);
  		if (err < 0)
-			return err;
-	}
-
-	hcd = usb_create_hcd(&ehci_platform_hc_driver, &dev->dev,
-			     dev_name(&dev->dev));
-	if (!hcd) {
-		err = -ENOMEM;
-		goto err_power;
+			goto err_put_clks;
  	}
 
  	hcd->rsrc_start = res_mem->start;

@@ -126,21 +211,25 @@ static int ehci_platform_probe(struct platform_device *dev)
  	hcd->regs = devm_ioremap_resource(&dev->dev, res_mem);
  	if (IS_ERR(hcd->regs)) {
  		err = PTR_ERR(hcd->regs);
-		goto err_put_hcd;
+		goto err_power;
  	}
  	err = usb_add_hcd(hcd, irq, IRQF_SHARED);
  	if (err)
-		goto err_put_hcd;
-
-	platform_set_drvdata(dev, hcd);
+		goto err_power;
 
  	return err;
 
-err_put_hcd:
-	usb_put_hcd(hcd);
  err_power:
  	if (pdata->power_off)
  		pdata->power_off(dev);
+err_put_clks:
+	while (--clk >= 0)
+		clk_put(priv->clks[clk]);
+err_put_hcd:
+	if (pdata == &ehci_platform_defaults)
+		dev->dev.platform_data = NULL;
+
+	usb_put_hcd(hcd);
 
  	return err;
  }

@@ -149,13 +238,19 @@ static int ehci_platform_remove(struct platform_device *dev)
  {
  	struct usb_hcd *hcd = platform_get_drvdata(dev);
  	struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
+	struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
+	int clk;
 
  	usb_remove_hcd(hcd);
-	usb_put_hcd(hcd);
 
  	if (pdata->power_off)
  		pdata->power_off(dev);
 
+	for (clk = 0; priv->clks[clk] && clk < EHCI_MAX_CLKS; clk++)
+		clk_put(priv->clks[clk]);
+
+	usb_put_hcd(hcd);
+
  	if (pdata == &ehci_platform_defaults)
  		dev->dev.platform_data = NULL;
 

Quoted 72 lines · Hans de Goede

Currently ehci-platform is only used in combination with devicetree when used with some Via socs. By extending it to (optionally) get clks and a phy from devicetree, and enabling / disabling those on power_on / off, it can be used more generically. Specifically after this commit it can be used for the ehci controller on Allwinner sunxi SoCs.

Since ehci-platform is intended to handle any generic enough non pci ehci device, add a "usb-ehci" compatibility string.

There already is a usb-ehci device-tree bindings document, update this with clks and phy bindings info.

Although actually quite generic so far the via,vt8500 compatibilty string had its own bindings document. Somehow we even ended up with 2 of them. Since these provide no extra information over the generic usb-ehci documentation, this patch removes them.

The ehci-ppc-of.c driver also claims the usb-ehci compatibility string, even though it mostly is ibm,usb-ehci-440epx specific. ehci-platform.c is not needed on ppc platforms, so add a !PPC_OF dependency to it to avoid 2 drivers claiming the same compatibility string getting build on ppc.

Signed-off-by Hans de Goede <[email protected]>

---
  Documentation/devicetree/bindings/usb/usb-ehci.txt |  25 +++-
  .../devicetree/bindings/usb/via,vt8500-ehci.txt    |  15 ---
  .../devicetree/bindings/usb/vt8500-ehci.txt        |  12 --
  drivers/usb/host/Kconfig                           |   1 +
  drivers/usb/host/ehci-platform.c                   | 149 +++++++++++++++++----
  5 files changed, 142 insertions(+), 60 deletions(-)

delete mode 100644 Documentation/devicetree/bindings/usb/via,vt8500-ehci.txt delete mode 100644 Documentation/devicetree/bindings/usb/vt8500-ehci.txt

Documentation/devicetree/bindings/usb/usb-ehci.txt +18 -7

index fa18612..fad10f3 100644
@@ -7,13 +7,14 @@ Required properties:
      (debug-port or other) can be also specified here, but only after
      definition of standard EHCI registers.
    - interrupts : one EHCI interrupt should be described here.
-If device registers are implemented in big endian mode, the device
-node should have "big-endian-regs" property.
-If controller implementation operates with big endian descriptors,
-"big-endian-desc" property should be specified.
-If both big endian registers and descriptors are used by the controller
-implementation, "big-endian" property can be specified instead of having
-both "big-endian-regs" and "big-endian-desc".
+
+Optional properties:
+ - big-endian-regs : boolean, set this for hcds with big-endian registers
+ - big-endian-desc : boolean, set this for hcds with big-endian descriptors
+ - big-endian : boolean, for hcds with big-endian-regs + big-endian-desc
+ - clocks : a list of phandle + clock specifier pairs
+ - phys : phandle + phy specifier pair
+ - phy-names : "usb"
  Example (Sequoia 440EPx):
      ehci at e0000300 {

@@ -23,3 +24,13 @@ Example (Sequoia 440EPx):
         reg = <0 e0000300 90 0 e0000390 70>;
         big-endian;
     };
+
+Example (Allwinner sun4i A10 SoC):
+   ehci0: ehci at 0x01c14000 {
+       compatible = "allwinner,sun4i-a10-ehci", "usb-ehci";
+       reg = <0x01c14000 0x100>;
+       interrupts = <39>;
+       clocks = <&ahb_gates 1>;
+       phys = <&usbphy 1>;
+       phy-names = "usb";
+   };

You have removed the documentation for the via,vt8500-ehci and wm,prizm-ehci bindings (which in itself isn't really an issue), and left them in the driver (again, not an issue)

- except now we have two bindings without any binding documentation?!?

I'm not sure where the 'wm,prizm-ehci' string came from (presumably me some time ago), but it isn't used and could be dropped. All WonderMedia SoCs use the 'via,vt8500-ehci' - Doing a quick grep of arch/arm/boot/dts shows no usage of 'wm,prizm-ehci'.

Arguably, the dtsi files for the WonderMedia SoCs could be updated to include 'usb-ehci' as a second compatible string

and the 'via,vt8500-ehci' could be dropped from the driver - but it does mean that old dts files won't work with the current kernel (and I think that's a no-no).

Currently ehci-platform is only used in combination with devicetree when used with some Via socs. By extending it to (optionally) get clks and a phy from devicetree, and enabling / disabling those on power_on / off, it can be used more generically. Specifically after this commit it can be used for the ehci controller on Allwinner sunxi SoCs.

Since ehci-platform is intended to handle any generic enough non pci ehci device, add a "usb-ehci" compatibility string.

There already is a usb-ehci device-tree bindings document, update this with clks and phy bindings info.

Although actually quite generic so far the via,vt8500 compatibilty string had its own bindings document. Somehow we even ended up with 2 of them. Since these provide no extra information over the generic usb-ehci documentation, this patch removes them.

The ehci-ppc-of.c driver also claims the usb-ehci compatibility string, even though it mostly is ibm,usb-ehci-440epx specific. ehci-platform.c is not needed on ppc platforms, so add a !PPC_OF dependency to it to avoid 2 drivers claiming the same compatibility string getting build on ppc.

Signed-off-by Hans de Goede <[email protected]>