[PATCH v2 1/2 RESEND] usb: core: phy: add support for PHY calibration

Marek Szyprowski
2019-08-29T05:30:53Z

Some PHYs (for example Exynos5 USB3.0 DRD PHY) require calibration to be
done after every USB HCD reset. Generic PHY framework has been already
extended with phy_calibrate() function in commit 36914111e682 ("drivers:
phy: add calibrate method"). This patch adds support for it to generic
PHY handling code in USB HCD core.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Anand Moon <linux.amoon@gmail.com>
Tested-by: Jochen Sprickerhof <jochen@sprickerhof.de>
---
drivers/usb/core/hcd.c | 7 +++++++
drivers/usb/core/phy.c | 21 +++++++++++++++++++++
drivers/usb/core/phy.h | 1 +
3 files changed, 29 insertions(+)

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 88533938ce19..b89936c1df23 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -2291,6 +2291,9 @@ int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
hcd->state = HC_STATE_RESUMING;
status = hcd->driver->bus_resume(hcd);
clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
+ if (status == 0)
+ status = usb_phy_roothub_calibrate(hcd->phy_roothub);
+
if (status == 0) {
struct usb_device *udev;
int port1;
@@ -2864,6 +2867,10 @@ int usb_add_hcd(struct usb_hcd *hcd,
}
hcd->rh_pollable = 1;

+ retval = usb_phy_roothub_calibrate(hcd->phy_roothub);
+ if (retval)
+ goto err_hcd_driver_setup;
+
/* NOTE: root hub and controller capabilities may not be the same */
if (device_can_wakeup(hcd->self.controller)
&& device_can_wakeup(&hcd->self.root_hub->dev))
diff --git a/drivers/usb/core/phy.c b/drivers/usb/core/phy.c
index 7580493b867a..fb1588e7c282 100644
--- a/drivers/usb/core/phy.c
+++ b/drivers/usb/core/phy.c
@@ -151,6 +151,27 @@ int usb_phy_roothub_set_mode(struct usb_phy_roothub *phy_roothub,
}
EXPORT_SYMBOL_GPL(usb_phy_roothub_set_mode);

+int usb_phy_roothub_calibrate(struct usb_phy_roothub *phy_roothub)
+{
+ struct usb_phy_roothub *roothub_entry;
+ struct list_head *head;
+ int err;
+
+ if (!phy_roothub)
+ return 0;
+
+ head = &phy_roothub->list;
+
+ list_for_each_entry(roothub_entry, head, list) {
+ err = phy_calibrate(roothub_entry->phy);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(usb_phy_roothub_calibrate);
+
int usb_phy_roothub_power_on(struct usb_phy_roothub *phy_roothub)
{
struct usb_phy_roothub *roothub_entry;
diff --git a/drivers/usb/core/phy.h b/drivers/usb/core/phy.h
index dad564e2d2d4..20a267cd986b 100644
--- a/drivers/usb/core/phy.h
+++ b/drivers/usb/core/phy.h
@@ -18,6 +18,7 @@ int usb_phy_roothub_exit(struct usb_phy_roothub *phy_roothub);

int usb_phy_roothub_set_mode(struct usb_phy_roothub *phy_roothub,
enum phy_mode mode);
+int usb_phy_roothub_calibrate(struct usb_phy_roothub *phy_roothub);
int usb_phy_roothub_power_on(struct usb_phy_roothub *phy_roothub);
void usb_phy_roothub_power_off(struct usb_phy_roothub *phy_roothub);

--
2.17.1