Subject: [RESEND 1/2] usb: ehci-exynos: Make provision for vdd regulators

From: [email-masked] (Anand Moon)
Date: Sun, 7 Jun 2015 22:50:41 +0930

Facilitate getting required 3.3V and 1.0V VDD supply for
EHCI controller on Exynos.

With the patches for regulators' nodes merged in 3.15:
c8c253f ARM: dts: Add regulator entries to smdk5420
275dcd2 ARM: dts: add max77686 pmic node for smdk5250,
the exynos systems turn on only minimal number of regulators.

Until now, the VDD regulator supplies were either turned on
by the bootloader, or the regulators were enabled by default
in the kernel, so that the controller drivers did not need to
care about turning on these regulators on their own.
This was rather bad about these controller drivers.
So ensuring now that the controller driver requests the necessary
VDD regulators (if available, unless there are direct VDD rails),
and enable them so as to make them working.

Signed-off-by: Vivek Gautam <[email-masked]>
Signed-off-by: Anand Moon <[email-masked]>
Cc: Jingoo Han <[email-masked]>
Cc: Alan Stern <[email-masked]>
---
Initial version of this patch was part of following series, though
they are not dependent on each other, resubmitting after rebasing.

http://lists.infradead.org/pipermail/linux-arm-kernel/2014-June/266418.html
---
 .../devicetree/bindings/usb/exynos-usb.txt         |  2 +
 drivers/usb/host/ehci-exynos.c                     | 55 +++++++++++++++++++++-
 2 files changed, 56 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/usb/exynos-usb.txt b/Documentation/devicetree/bindings/usb/exynos-usb.txt
index 9b4dbe3..776fa03 100644
--- a/Documentation/devicetree/bindings/usb/exynos-usb.txt
+++ b/Documentation/devicetree/bindings/usb/exynos-usb.txt
@@ -23,6 +23,8 @@ Required properties:
 Optional properties:
  - samsung,vbus-gpio:  if present, specifies the GPIO that
    needs to be pulled up for the bus to be powered.
+ - vdd33-supply: handle to 3.3V Vdd supply regulator for the controller.
+ - vdd10-supply: handle to 1.0V Vdd supply regulator for the controller.
 
 Example:
 
diff --git a/drivers/usb/host/ehci-exynos.c b/drivers/usb/host/ehci-exynos.c
index df538fd..4f8f9d2 100644
--- a/drivers/usb/host/ehci-exynos.c
+++ b/drivers/usb/host/ehci-exynos.c
@@ -21,6 +21,7 @@
 #include <linux/of_gpio.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
 #include <linux/usb.h>
 #include <linux/usb/hcd.h>
 
@@ -45,6 +46,8 @@ static struct hc_driver __read_mostly exynos_ehci_hc_driver;
 struct exynos_ehci_hcd {
 	struct clk *clk;
 	struct phy *phy[PHY_NUMBER];
+	struct regulator *vdd33;
+	struct regulator *vdd10;
 };
 
 #define to_exynos_ehci(hcd) (struct exynos_ehci_hcd *)(hcd_to_ehci(hcd)->priv)
@@ -170,7 +173,27 @@ static int exynos_ehci_probe(struct platform_device *pdev)
 
 	err = exynos_ehci_get_phy(&pdev->dev, exynos_ehci);
 	if (err)
-		goto fail_clk;
+		goto fail_regulator1;
+
+	exynos_ehci->vdd33 = devm_regulator_get_optional(&pdev->dev, "vdd33");
+	if (!IS_ERR(exynos_ehci->vdd33)) {
+		err = regulator_enable(exynos_ehci->vdd33);
+		if (err) {
+			dev_err(&pdev->dev,
+				"Failed to enable 3.3V Vdd supply\n");
+			goto fail_regulator1;
+		}
+	}
+
+	exynos_ehci->vdd10 = devm_regulator_get_optional(&pdev->dev, "vdd10");
+	if (!IS_ERR(exynos_ehci->vdd10)) {
+		err = regulator_enable(exynos_ehci->vdd10);
+		if (err) {
+			dev_err(&pdev->dev,
+				"Failed to enable 1.0V Vdd supply\n");
+			goto fail_regulator2;
+		}
+	}
 
 skip_phy:
 
@@ -231,6 +254,10 @@ fail_add_hcd:
 fail_io:
 	clk_disable_unprepare(exynos_ehci->clk);
 fail_clk:
+	regulator_disable(exynos_ehci->vdd10);
+fail_regulator2:
+	regulator_disable(exynos_ehci->vdd33);
+fail_regulator1:
 	usb_put_hcd(hcd);
 	return err;
 }
@@ -246,6 +273,11 @@ static int exynos_ehci_remove(struct platform_device *pdev)
 
 	clk_disable_unprepare(exynos_ehci->clk);
 
+	if (!IS_ERR(exynos_ehci->vdd33))
+		regulator_disable(exynos_ehci->vdd33);
+	if (!IS_ERR(exynos_ehci->vdd10))
+		regulator_disable(exynos_ehci->vdd10);
+
 	usb_put_hcd(hcd);
 
 	return 0;
@@ -268,6 +300,11 @@ static int exynos_ehci_suspend(struct device *dev)
 
 	clk_disable_unprepare(exynos_ehci->clk);
 
+	if (!IS_ERR(exynos_ehci->vdd33))
+		regulator_disable(exynos_ehci->vdd33);
+	if (!IS_ERR(exynos_ehci->vdd10))
+		regulator_disable(exynos_ehci->vdd10);
+
 	return rc;
 }
 
@@ -277,6 +314,22 @@ static int exynos_ehci_resume(struct device *dev)
 	struct exynos_ehci_hcd *exynos_ehci = to_exynos_ehci(hcd);
 	int ret;
 
+	if (!IS_ERR(exynos_ehci->vdd33)) {
+		ret = regulator_enable(exynos_ehci->vdd33);
+		if (ret) {
+			dev_err(dev, "Failed to enable 3.3V Vdd supply\n");
+			return ret;
+		}
+	}
+
+	if (!IS_ERR(exynos_ehci->vdd10)) {
+		ret = regulator_enable(exynos_ehci->vdd10);
+		if (ret) {
+			dev_err(dev, "Failed to enable 1.0V Vdd supply\n");
+			return ret;
+		}
+	}
+
 	clk_prepare_enable(exynos_ehci->clk);
 
 	ret = exynos_ehci_phy_enable(dev);
-- 
2.4.3