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>
---
drivers/usb/host/ehci-atmel.c | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/drivers/usb/host/ehci-atmel.c b/drivers/usb/host/ehci-atmel.c
index 56a8850..5a15e3d 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 +178,29 @@ 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),
},
};
--
2.1.4
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