[PATCH 1/3] USB: host: ehci_atmel: Move global variables to private struct

[Alan Stern]

On Sat, 17 Jan 2015, Sylvain Rochet wrote:

> This patch move Atmel EHCI global variables (clocks ptr and clocked
> boolean) to private struct atmel_ehci, appended at the end of the parent
> struct usb_hcd.
> 
> Signed-off-by: Sylvain Rochet <sylvain.rochet at finsecur.com>
> ---
>  drivers/usb/host/ehci-atmel.c | 75 +++++++++++++++++++++++++++----------------
>  1 file changed, 48 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/usb/host/ehci-atmel.c b/drivers/usb/host/ehci-atmel.c
> index 2e0043b..a47fe3f 100644
> --- a/drivers/usb/host/ehci-atmel.c
> +++ b/drivers/usb/host/ehci-atmel.c
> @@ -30,45 +30,62 @@ static const char hcd_name[] = "ehci-atmel";
>  static struct hc_driver __read_mostly ehci_atmel_hc_driver;
>  
>  /* interface and function clocks */
> -static struct clk *iclk, *fclk, *uclk;
> -static int clocked;
> +struct atmel_ehci {
> +	struct ehci_hcd	ehci;
> +
> +	struct clk *iclk;
> +	struct clk *fclk;
> +	struct clk *uclk;
> +	bool clocked;
> +};
>  
>  /*-------------------------------------------------------------------------*/
>  
> -static void atmel_start_clock(void)
> +static inline struct atmel_ehci *hcd_to_atmel_ehci(struct usb_hcd *hcd)
> +{
> +	return (struct atmel_ehci *) hcd->hcd_priv;
> +}

This is not the right way to do it.  For an example of the right way, 
see the ehci-platform.c file.  Your private structure is stored in 
ehci->priv, and its size is specified by the .extra_priv_size member of 
an ehci_driver_overrides structure passed to ehci_init_driver().

Nevertheless, I approve the idea of getting rid of global variables.

Alan Stern