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USB: host: ehci-atmel: Add suspend/resume support

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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@finsecur.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Sylvain Rochet 2015-01-20 14:38:59 +01:00 committed by Greg Kroah-Hartman
parent fbaecff06a
commit ca2c1dc04b
1 changed files with 31 additions and 0 deletions
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31
drivers/usb/host/ehci-atmel.c
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@ -37,6 +37,8 @@ static int clocked;
static void atmel_start_clock(void) static void atmel_start_clock(void)
{ {
if (clocked)
return;
if (IS_ENABLED(CONFIG_COMMON_CLK)) { if (IS_ENABLED(CONFIG_COMMON_CLK)) {
clk_set_rate(uclk, 48000000); clk_set_rate(uclk, 48000000);
clk_prepare_enable(uclk); clk_prepare_enable(uclk);
@ -48,6 +50,8 @@ static void atmel_start_clock(void)
static void atmel_stop_clock(void) static void atmel_stop_clock(void)
{ {
if (!clocked)
return;
clk_disable_unprepare(fclk); clk_disable_unprepare(fclk);
clk_disable_unprepare(iclk); clk_disable_unprepare(iclk);
if (IS_ENABLED(CONFIG_COMMON_CLK)) if (IS_ENABLED(CONFIG_COMMON_CLK))
@ -174,6 +178,29 @@ static int ehci_atmel_drv_remove(struct platform_device *pdev)
return 0; 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 #ifdef CONFIG_OF
static const struct of_device_id atmel_ehci_dt_ids[] = { static const struct of_device_id atmel_ehci_dt_ids[] = {
{ .compatible = "atmel,at91sam9g45-ehci" }, { .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); MODULE_DEVICE_TABLE(of, atmel_ehci_dt_ids);
#endif #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 = { static struct platform_driver ehci_atmel_driver = {
.probe = ehci_atmel_drv_probe, .probe = ehci_atmel_drv_probe,
.remove = ehci_atmel_drv_remove, .remove = ehci_atmel_drv_remove,
.shutdown = usb_hcd_platform_shutdown, .shutdown = usb_hcd_platform_shutdown,
.driver = { .driver = {
.name = "atmel-ehci", .name = "atmel-ehci",
.pm = &ehci_atmel_pm_ops,
.of_match_table = of_match_ptr(atmel_ehci_dt_ids), .of_match_table = of_match_ptr(atmel_ehci_dt_ids),
}, },
}; };