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Commit ca2c1dc0 authored by Sylvain Rochet's avatar Sylvain Rochet Committed by Greg Kroah-Hartman
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USB: host: ehci-atmel: Add suspend/resume support 



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: default avatarSylvain Rochet <sylvain.rochet@finsecur.com>
Acked-by: default avatarBoris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Acked-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: default avatarAlexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent fbaecff0

drivers/usb/host/ehci-atmel.c

+31 −0
Original line number Diff line number Diff line
@@ -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 +178,29 @@ static int ehci_atmel_drv_remove(struct platform_device *pdev) 
	return 0;

}



#ifdef CONFIG_PM

static int ehci_atmel_drv_suspend(struct device *dev)

{

	struct usb_hcd *hcd = dev_get_drvdata(dev);

	int ret;



	ret = ehci_suspend(hcd, false);

	if (ret)

		return ret;



	atmel_stop_clock();

	return 0;

}



static int ehci_atmel_drv_resume(struct device *dev)

{

	struct usb_hcd *hcd = dev_get_drvdata(dev);



	atmel_start_clock();

	return ehci_resume(hcd, false);

}

#endif



#ifdef CONFIG_OF

static const struct of_device_id atmel_ehci_dt_ids[] = {

	{ .compatible = "atmel,at91sam9g45-ehci" },
@@ -183,12 +210,16 @@ static const struct of_device_id atmel_ehci_dt_ids[] = { 
MODULE_DEVICE_TABLE(of, atmel_ehci_dt_ids);

#endif



static SIMPLE_DEV_PM_OPS(ehci_atmel_pm_ops, ehci_atmel_drv_suspend,

					ehci_atmel_drv_resume);



static struct platform_driver ehci_atmel_driver = {

	.probe		= ehci_atmel_drv_probe,

	.remove		= ehci_atmel_drv_remove,

	.shutdown	= usb_hcd_platform_shutdown,

	.driver		= {

		.name	= "atmel-ehci",

		.pm	= &ehci_atmel_pm_ops,

		.of_match_table	= of_match_ptr(atmel_ehci_dt_ids),

	},

};