ehci-platform: Add support for clks and phy passed through devicetree

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 <hdegoede@redhat.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 124 insertions, 24 deletions

diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index a9707da..e28cbe0 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -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
diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
index 01536cf..5ebd0b7 100644
--- a/drivers/usb/host/ehci-platform.c
+++ b/drivers/usb/host/ehci-platform.c
@@ -3,6 +3,7 @@
  *
  * Copyright 2007 Steven Brown <sbrown@cortland.com>
  * Copyright 2010-2012 Hauke Mehrtens <hauke@hauke-m.de>
+ * Copyright 2014 Hans de Goede <hdegoede@redhat.com>
  *
  * Derived from the ohci-ssb driver
  * Copyright 2007 Michael Buesch <m@bues.ch>
@@ -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; clk < EHCI_MAX_CLKS && priv->clks[clk]; 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 err, irq, clk = 0;
 
 	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;
@@ -126,22 +211,28 @@ 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;
+		goto err_power;
 
 	device_wakeup_enable(hcd->self.controller);
 	platform_set_drvdata(dev, hcd);
 
 	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;
 }
@@ -150,13 +241,19 @@ 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; clk < EHCI_MAX_CLKS && priv->clks[clk]; clk++)
+		clk_put(priv->clks[clk]);
+
+	usb_put_hcd(hcd);
+
 	if (pdata == &ehci_platform_defaults)
 		dev->dev.platform_data = NULL;
 
@@ -207,8 +304,10 @@ static int ehci_platform_resume(struct device *dev)
 static const struct of_device_id vt8500_ehci_ids[] = {
 	{ .compatible = "via,vt8500-ehci", },
 	{ .compatible = "wm,prizm-ehci", },
+	{ .compatible = "usb-ehci", },
 	{}
 };
+MODULE_DEVICE_TABLE(of, vt8500_ehci_ids);
 
 static const struct platform_device_id ehci_platform_table[] = {
 	{ "ehci-platform", 0 },