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

From: Krzysztof Kozlowski
Date: Sun Jun 07 2015 - 22:10:35 EST


On 07.06.2015 22:20, Anand Moon wrote:
> 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 <gautam.vivek@xxxxxxxxxxx>
> Signed-off-by: Anand Moon <linux.amoon@xxxxxxxxx>
> Cc: Jingoo Han <jg1.han@xxxxxxxxxxx>
> Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> ---
> 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

So you just took Vivek's patch along with all the credits... That is not
how we usually do this.

I would expect that rebasing a patch won't change the author unless this
is fine with Vivek.

> ---
> .../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);

if (!IS_ERR()).

> +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);
> +


Is EHCI a wakeup source? If yes then how disabling regulators during
suspend affects waking up process?

Best regards,
Krzysztof

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