From: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx>
Most onboard USB hubs have a dedicated crystal oscillator but on some
boards the clock signal for the hub is provided by the SoC.
In order to support this, we add the possibility of specifying a
clock in the devicetree that gets enabled/disabled when the hub
is powered up/down.
Signed-off-by: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx>
---
Changes in v2:
* use %pe to print symbolic error name
---
drivers/usb/misc/onboard_usb_hub.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/drivers/usb/misc/onboard_usb_hub.c b/drivers/usb/misc/onboard_usb_hub.c
index 077824beffa01..0d84b16deab50 100644
--- a/drivers/usb/misc/onboard_usb_hub.c
+++ b/drivers/usb/misc/onboard_usb_hub.c
@@ -5,6 +5,7 @@
* Copyright (c) 2022, Google LLC
*/
+#include <linux/clk.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/err.h>
@@ -61,12 +62,19 @@ struct onboard_hub {
bool going_away;
struct list_head udev_list;
struct mutex lock;
+ struct clk *clk;
};
static int onboard_hub_power_on(struct onboard_hub *hub)
{
int err;
+ err = clk_prepare_enable(hub->clk);
+ if (err) {
+ dev_err(hub->dev, "failed to enable clock: %pe\n", ERR_PTR(err));
+ return err;
+ }
+
err = regulator_bulk_enable(hub->pdata->num_supplies, hub->supplies);
if (err) {
dev_err(hub->dev, "failed to enable supplies: %pe\n", ERR_PTR(err));
@@ -93,6 +101,8 @@ static int onboard_hub_power_off(struct onboard_hub *hub)
return err;
}
+ clk_disable_unprepare(hub->clk);
+
hub->is_powered_on = false;
return 0;
@@ -267,6 +277,10 @@ static int onboard_hub_probe(struct platform_device *pdev)
return err;
}
+ hub->clk = devm_clk_get_optional(dev, NULL);
+ if (IS_ERR(hub->clk))
+ return dev_err_probe(dev, PTR_ERR(hub->clk), "failed to get clock\n");
+
hub->reset_gpio = devm_gpiod_get_optional(dev, "reset",
GPIOD_OUT_HIGH);
if (IS_ERR(hub->reset_gpio))
--
2.42.1
