[PATCH 1/2] chipidea: ci_hdrc_imx: Allow handling the clock for an USB phy/hub

[Shawn Guo]

This should be sent to USB folks.  Copy Peter and Alex.

Shawn

On Thu, Nov 14, 2013 at 12:09:46AM -0200, Fabio Estevam wrote:
> From: Fabio Estevam <fabio.estevam at freescale.com>
> 
> When using external USB PHY or USB hub, it is common that they require a clock
> input.
> 
> 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 at freescale.com>
> ---
>  .../devicetree/bindings/usb/ci13xxx-imx.txt          |  2 ++
>  drivers/usb/chipidea/ci_hdrc_imx.c                   | 20 +++++++++++++++++++-
>  2 files changed, 21 insertions(+), 1 deletion(-)
> 
> 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 at 02184000 { /* USB OTG */
> diff --git a/drivers/usb/chipidea/ci_hdrc_imx.c b/drivers/usb/chipidea/ci_hdrc_imx.c
> index bb5d976..a197748 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;
>  };
>  
> @@ -107,10 +108,22 @@ static int ci_hdrc_imx_probe(struct platform_device *pdev)
>  		return ret;
>  	}
>  
> +	data->clk_phy = devm_clk_get(&pdev->dev, "phy");
> +	if (IS_ERR(data->clk_phy)) {
> +		data->clk_phy = NULL;
> +	} else {
> +		ret = clk_prepare_enable(data->clk_phy);
> +		if (ret) {
> +			dev_err(&pdev->dev,
> +				"Failed to enable clk_phy: %d\n", ret);
> +			goto err_clk;
> +		}
> +	}
> +
>  	data->phy = devm_usb_get_phy_by_phandle(&pdev->dev, "fsl,usbphy", 0);
>  	if (IS_ERR(data->phy)) {
>  		ret = PTR_ERR(data->phy);
> -		goto err_clk;
> +		goto err_clk_phy;
>  	}
>  
>  	pdata.phy = data->phy;
> @@ -157,6 +170,9 @@ static int ci_hdrc_imx_probe(struct platform_device *pdev)
>  
>  disable_device:
>  	ci_hdrc_remove_device(data->ci_pdev);
> +err_clk_phy:
> +	if (data->clk_phy)
> +		clk_disable_unprepare(data->clk_phy);
>  err_clk:
>  	clk_disable_unprepare(data->clk);
>  	return ret;
> @@ -168,6 +184,8 @@ static int ci_hdrc_imx_remove(struct platform_device *pdev)
>  
>  	pm_runtime_disable(&pdev->dev);
>  	ci_hdrc_remove_device(data->ci_pdev);
> +	if (data->clk_phy)
> +		clk_disable_unprepare(data->clk_phy);
>  	clk_disable_unprepare(data->clk);
>  
>  	return 0;
> -- 
> 1.8.1.2
>