On Thu, Nov 14, 2013 at 08:47:40AM -0200, Fabio Estevam wrote:
> From: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx>
>
> When using external USB PHY or USB hub, it is common that they require a clock
> input.
If it is an external USB PHY, the clock entry should be added at phy node.
If it is a USB HUB's reset/clock pin, there is no good place to
put them, only platform code is available now.
Alan, if there is an external USB HUB, but clock and reset pin needs to
be controlled, eg, after controller's initialization but before HUB's
enumeration. How we handle such kinds of case?
Peter
>
> Add a 'clk_phy' clock, so that it can be retrieved from the device tree and
> enabled in the driver, so that the clock can properly drive the external
> USB phy/hub.
>
> Tested on a imx6q-udoo board, that connects via USBH1 to a USB2514 hub.
>
> In this board the USB2514 is clocked from a 24MHz clock that comes from the
> imx6q CLKO2 pin.
>
> Signed-off-by: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx>
> ---
> Changes since v1:
> - Fix the clock error handling (Russell King)
>
> Documentation/devicetree/bindings/usb/ci13xxx-imx.txt | 2 ++
> drivers/usb/chipidea/ci_hdrc_imx.c | 13 +++++++++++++
> 2 files changed, 15 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/usb/ci13xxx-imx.txt b/Documentation/devicetree/bindings/usb/ci13xxx-imx.txt
> index b4b5b79..07ba38c 100644
> --- a/Documentation/devicetree/bindings/usb/ci13xxx-imx.txt
> +++ b/Documentation/devicetree/bindings/usb/ci13xxx-imx.txt
> @@ -18,6 +18,8 @@ Optional properties:
> - vbus-supply: regulator for vbus
> - disable-over-current: disable over current detect
> - external-vbus-divider: enables off-chip resistor divider for Vbus
> +- clocks: phandle to the clock that drives the USB hub
> +- clock-names: must be "phy"
>
> Examples:
> usb@02184000 { /* USB OTG */
> diff --git a/drivers/usb/chipidea/ci_hdrc_imx.c b/drivers/usb/chipidea/ci_hdrc_imx.c
> index bb5d976..3edf10a 100644
> --- a/drivers/usb/chipidea/ci_hdrc_imx.c
> +++ b/drivers/usb/chipidea/ci_hdrc_imx.c
> @@ -27,6 +27,7 @@ struct ci_hdrc_imx_data {
> struct usb_phy *phy;
> struct platform_device *ci_pdev;
> struct clk *clk;
> + struct clk *clk_phy;
> struct imx_usbmisc_data *usbmisc_data;
> };
>
> @@ -148,6 +149,16 @@ static int ci_hdrc_imx_probe(struct platform_device *pdev)
> }
> }
>
> + data->clk_phy = devm_clk_get(&pdev->dev, "phy");
> + if (!IS_ERR(data->clk_phy)) {
> + ret = clk_prepare_enable(data->clk_phy);
> + if (ret) {
> + dev_err(&pdev->dev,
> + "Failed to enable clk_phy: %d\n", ret);
> + goto disable_device;
> + }
> + }
> +
> platform_set_drvdata(pdev, data);
>
> pm_runtime_no_callbacks(&pdev->dev);
> @@ -167,6 +178,8 @@ static int ci_hdrc_imx_remove(struct platform_device *pdev)
> struct ci_hdrc_imx_data *data = platform_get_drvdata(pdev);
>
> pm_runtime_disable(&pdev->dev);
> + if (!IS_ERR(data->clk_phy))
> + clk_disable_unprepare(data->clk_phy);
> ci_hdrc_remove_device(data->ci_pdev);
> clk_disable_unprepare(data->clk);
>
> --
> 1.8.1.2
>
>
--
Best Regards,
Peter Chen
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