On Sat, 17 Jan 2015 16:36:34 +0100
Sylvain Rochet <sylvain.rochet@xxxxxxxxxxxx> wrote:
> This patch add suspend/resume support for Atmel EHCI, mostly
> about disabling and unpreparing clocks so USB PLL is stopped
> before entering sleep state.
>
> Signed-off-by: Sylvain Rochet <sylvain.rochet@xxxxxxxxxxxx>
Acked-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/usb/host/ehci-atmel.c | 32 ++++++++++++++++++++++++++++++++
> 1 file changed, 32 insertions(+)
>
> diff --git a/drivers/usb/host/ehci-atmel.c b/drivers/usb/host/ehci-atmel.c
> index 56a8850..2e0043b 100644
> --- a/drivers/usb/host/ehci-atmel.c
> +++ b/drivers/usb/host/ehci-atmel.c
> @@ -37,6 +37,8 @@ static int clocked;
>
> static void atmel_start_clock(void)
> {
> + if (clocked)
> + return;
> if (IS_ENABLED(CONFIG_COMMON_CLK)) {
> clk_set_rate(uclk, 48000000);
> clk_prepare_enable(uclk);
> @@ -48,6 +50,8 @@ static void atmel_start_clock(void)
>
> static void atmel_stop_clock(void)
> {
> + if (!clocked)
> + return;
> clk_disable_unprepare(fclk);
> clk_disable_unprepare(iclk);
> if (IS_ENABLED(CONFIG_COMMON_CLK))
> @@ -174,6 +178,32 @@ static int ehci_atmel_drv_remove(struct platform_device *pdev)
> return 0;
> }
>
> +#ifdef CONFIG_PM
> +static int ehci_atmel_drv_suspend(struct platform_device *pdev, pm_message_t mesg)
> +{
> + struct usb_hcd *hcd = platform_get_drvdata(pdev);
> + int ret;
> +
> + ret = ehci_suspend(hcd, false);
> + if (ret)
> + return ret;
> +
> + atmel_stop_clock();
> + return 0;
> +}
> +
> +static int ehci_atmel_drv_resume(struct platform_device *pdev)
> +{
> + struct usb_hcd *hcd = platform_get_drvdata(pdev);
> +
> + atmel_start_clock();
> + return ehci_resume(hcd, false);
> +}
> +#else
> +#define ehci_atmel_drv_suspend NULL
> +#define ehci_atmel_drv_resume NULL
> +#endif
> +
> #ifdef CONFIG_OF
> static const struct of_device_id atmel_ehci_dt_ids[] = {
> { .compatible = "atmel,at91sam9g45-ehci" },
> @@ -187,6 +217,8 @@ static struct platform_driver ehci_atmel_driver = {
> .probe = ehci_atmel_drv_probe,
> .remove = ehci_atmel_drv_remove,
> .shutdown = usb_hcd_platform_shutdown,
> + .suspend = ehci_atmel_drv_suspend,
> + .resume = ehci_atmel_drv_resume,
> .driver = {
> .name = "atmel-ehci",
> .of_match_table = of_match_ptr(atmel_ehci_dt_ids),
--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
