On Wed, Nov 14, 2012 at 05:19:03PM +0100, Michael Grzeschik wrote:
> This patch adds support for a second and third clock to the chipidea driver. 
> On
> modern freescale ARM cores like the imx51, imx53 and imx6q three clocks 
> ("ahb",
> "ipg" and "per") must be enabled in order to access the USB core.
> 
> In the original driver, the clock was requested without specifying the
> connection id, further all mainline ARM archs with support for the chipidea
> core (imx23, imx28) register their USB clock without a connection id.
> 
> This patch first renames the existing clk variable to clk_ahb. The connection
> id "ahb" is added to the devm_clk_get() call. Then the clocks "ipg" and "per"
> are requested. As all archs don't specify a connection id, all clk_get return
> the same clock. This ensures compatibility to existing USB support and adds
> support for imx5x at the same time.
> 
> This patch has been tested on imx28 and on imx53 with seperate "ahb", "ipg"
> and "per" clocks.
mx23, mx28, and mx6q has the same usb clock sources and different with
mxc (mx5x, mx3x).

I am not sure which method is better:
- Add dummy clock at clock.c
- Add platform information(id_table or something similar) at driver.

Add dummy clock may confuse some users, for example, mx6q has no
"per" and "ipg" clock at all.
> 
> Signed-off-by: Michael Grzeschik <m.grzesc...@pengutronix.de>
> Signed-off-by: Marc Kleine-Budde <m...@pengutronix.de>
> ---
>  drivers/usb/chipidea/ci13xxx_imx.c |   54 
> ++++++++++++++++++++++++++++++------
>  1 file changed, 45 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/usb/chipidea/ci13xxx_imx.c 
> b/drivers/usb/chipidea/ci13xxx_imx.c
> index 935de97..570aedf 100644
> --- a/drivers/usb/chipidea/ci13xxx_imx.c
> +++ b/drivers/usb/chipidea/ci13xxx_imx.c
> @@ -32,7 +32,9 @@ struct ci13xxx_imx_data {
>       struct device_node *phy_np;
>       struct usb_phy *phy;
>       struct platform_device *ci_pdev;
> -     struct clk *clk;
> +     struct clk *clk_ahb;
> +     struct clk *clk_ipg;
> +     struct clk *clk_per;
>       struct regulator *reg_vbus;
>  };
>  
> @@ -144,20 +146,48 @@ static int __devinit ci13xxx_imx_probe(struct 
> platform_device *pdev)
>               dev_warn(&pdev->dev, "pinctrl get/select failed, err=%ld\n",
>                       PTR_ERR(pinctrl));
>  
> -     data->clk = devm_clk_get(&pdev->dev, NULL);
> -     if (IS_ERR(data->clk)) {
> +     data->clk_ahb = devm_clk_get(&pdev->dev, "ahb");
> +     if (IS_ERR(data->clk_ahb)) {
>               dev_err(&pdev->dev,
> -                     "Failed to get clock, err=%ld\n", PTR_ERR(data->clk));
> -             return PTR_ERR(data->clk);
> +                     "Failed to get ahb clock, err=%ld\n", 
> PTR_ERR(data->clk_ahb));
> +             return PTR_ERR(data->clk_ahb);
>       }
>  
> -     ret = clk_prepare_enable(data->clk);
> +     data->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
> +     if (IS_ERR(data->clk_ipg)) {
> +             dev_err(&pdev->dev,
> +                     "Failed to get ipg clock, err=%ld\n", 
> PTR_ERR(data->clk_ipg));
> +             return PTR_ERR(data->clk_ipg);
> +     }
> +
> +     data->clk_per = devm_clk_get(&pdev->dev, "per");
> +     if (IS_ERR(data->clk_per)) {
> +             dev_err(&pdev->dev,
> +                     "Failed to get per clock, err=%ld\n", 
> PTR_ERR(data->clk_per));
> +             return PTR_ERR(data->clk_per);
> +     }
> +
> +     ret = clk_prepare_enable(data->clk_ahb);
>       if (ret) {
>               dev_err(&pdev->dev,
> -                     "Failed to prepare or enable clock, err=%d\n", ret);
> +                     "Failed to prepare or enable ahb clock, err=%d\n", ret);
>               return ret;
>       }
>  
> +     ret = clk_prepare_enable(data->clk_ipg);
> +     if (ret) {
> +             dev_err(&pdev->dev,
> +                     "Failed to prepare or enable ipg clock, err=%d\n", ret);
> +             goto err_ipg_failed;
> +     }
> +
> +     ret = clk_prepare_enable(data->clk_per);
> +     if (ret) {
> +             dev_err(&pdev->dev,
> +                     "Failed to prepare or enable per clock, err=%d\n", ret);
> +             goto err_per_failed;
> +     }
> +
>       phy_np = of_parse_phandle(pdev->dev.of_node, "fsl,usbphy", 0);
>       if (phy_np) {
>               data->phy_np = phy_np;
> @@ -246,7 +276,11 @@ static int __devinit ci13xxx_imx_probe(struct 
> platform_device *pdev)
>  put_np:
>       if (phy_np)
>               of_node_put(phy_np);
> -     clk_disable_unprepare(data->clk);
> +     clk_disable_unprepare(data->clk_per);
> +err_per_failed:
> +     clk_disable_unprepare(data->clk_ipg);
> +err_ipg_failed:
> +     clk_disable_unprepare(data->clk_ahb);
>  
>       return ret;
>  }
> @@ -268,7 +302,9 @@ static int __devexit ci13xxx_imx_remove(struct 
> platform_device *pdev)
>  
>       of_node_put(data->phy_np);
>  
> -     clk_disable_unprepare(data->clk);
> +     clk_disable_unprepare(data->clk_per);
> +     clk_disable_unprepare(data->clk_ipg);
> +     clk_disable_unprepare(data->clk_ahb);
>  
>       platform_set_drvdata(pdev, NULL);
>  
> -- 
> 1.7.10.4
> 
> --
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> 

-- 

Best Regards,
Peter Chen

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