Re: [PATCH 4/4] usb: s3c-hsotg: Enable HCLK for the OTG module.

[Ben Dooks <ben-linux@fluff.org>]

On Fri, May 28, 2010 at 11:41:17AM +0900, Kukjin Kim wrote:
> From: Thomas Abraham <thomas.ab@samsung.com>
> 
> This patch modifies the following in S3C hsotg driver.
> 
> 1. Gets a reference to the USB OTG hclk clock and enables it. This is
>    required for plaforms on which the USB OTG hclk is disabled during
>    the boot time clock intialization.
> 
> 2. Add necessary clock clean up in case of error during initialization
>    failure or during module unload.
> 
> 3. Add a new field 'clk_otg' in 'struct s3c_hsotg' to maintain a
>    reference to the USB OTG hclk clock.
> 
> Signed-off-by: Thomas Abraham <thomas.ab@samsung.com>
> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
> ---
>  drivers/usb/gadget/s3c-hsotg.c |   17 +++++++++++++++++
>  1 files changed, 17 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/usb/gadget/s3c-hsotg.c b/drivers/usb/gadget/s3c-hsotg.c
> index 81c47d2..526d081 100644
> --- a/drivers/usb/gadget/s3c-hsotg.c
> +++ b/drivers/usb/gadget/s3c-hsotg.c
> @@ -130,6 +130,7 @@ struct s3c_hsotg_ep {
>   * @dev: The parent device supplied to the probe function
>   * @driver: USB gadget driver
>   * @plat: The platform specific configuration data.
> + * @clk_otg: The hclk for otg module.
>   * @regs: The memory area mapped for accessing registers.
>   * @regs_res: The resource that was allocated when claiming register space.
>   * @irq: The IRQ number we are using
> @@ -147,6 +148,7 @@ struct s3c_hsotg {
>  	struct device		 *dev;
>  	struct usb_gadget_driver *driver;
>  	struct s3c_hsotg_plat	 *plat;
> +	struct clk		 *clk_otg;
>  
>  	void __iomem		*regs;
>  	struct resource		*regs_res;
> @@ -3269,6 +3271,14 @@ static int __devinit s3c_hsotg_probe(struct platform_device *pdev)
>  		goto err_regs_res;
>  	}
>  
> +	hsotg->clk_otg = clk_get(&pdev->dev, "otg");
> +	if (IS_ERR(hsotg->clk_otg)) {
> +		dev_err(dev, "failed to find usb otg clock source\n");
> +		ret = -ENODEV;

hmm, -ENODEV isn't really the right error to return here, it'll
get silently ignored by the device core.

> +		goto err_noclk;
> +	}
> +	clk_enable(hsotg->clk_otg);
> +
>  	ret = platform_get_irq(pdev, 0);
>  	if (ret < 0) {
>  		dev_err(dev, "cannot find IRQ\n");
> @@ -3330,6 +3340,10 @@ static int __devinit s3c_hsotg_probe(struct platform_device *pdev)
>  	return 0;
>  
>  err_regs:
> +	clk_disable(hsotg->clk_otg);
> +	clk_put(hsotg->clk_otg);
> +
> +err_noclk:
>  	iounmap(hsotg->regs);
>  
>  err_regs_res:
> @@ -3352,6 +3366,9 @@ static int __devexit s3c_hsotg_remove(struct platform_device *pdev)
>  	free_irq(hsotg->irq, hsotg);
>  	iounmap(hsotg->regs);
>  
> +	clk_disable(hsotg->clk_otg);
> +	clk_put(hsotg->clk_otg);
> +
>  	release_resource(hsotg->regs_res);
>  	kfree(hsotg->regs_res);
>  
> -- 
> 1.6.3.3
> 

-- 
-- 
Ben

Q:      What's a light-year?
A:      One-third less calories than a regular year.