This adds the config option to associate a regulator with each hub,
when the hub on a specific, interesting device path appears, then
the regular is powered while the logical hub exists.
Signed-off-by: Andy Green <andy.green@xxxxxxxxxx>
---
drivers/usb/core/Kconfig | 10 ++++++++++
drivers/usb/core/hub.c | 26 +++++++++++++++++++++++++-
2 files changed, 35 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/core/Kconfig b/drivers/usb/core/Kconfig
index f70c1a1..4a91eb1 100644
--- a/drivers/usb/core/Kconfig
+++ b/drivers/usb/core/Kconfig
@@ -95,3 +95,13 @@ config USB_OTG_BLACKLIST_HUB
and software costs by not supporting external hubs. So
are "Embedded Hosts" that don't offer OTG support.
+config USB_HUB_DEVICE_PATH_REGULATOR
+ bool "Support generic regulators at hubs"
+ select DEVICEPATH
+ depends on USB
+ default n
+ help
+ Allows you to use the device_path APIs to associate kernel regulators
+ with dynamically probed USB hubs, so the regulators are enabled
+ as the appropriate hub instance gets created and disabled as it
+ is destroyed.
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index a815fd2..49ebb5e 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -26,6 +26,7 @@
#include <linux/mutex.h>
#include <linux/freezer.h>
#include <linux/random.h>
+#include <linux/regulator/consumer.h>
#include <asm/uaccess.h>
#include <asm/byteorder.h>
@@ -54,7 +55,9 @@ struct usb_hub {
struct usb_device *hdev;
struct kref kref;
struct urb *urb; /* for interrupt polling pipe */
-
+#ifdef CONFIG_USB_HUB_DEVICE_PATH_REGULATOR
+ struct regulator *regulator; /* optional power control */
+#endif
/* buffer for urb ... with extra space in case of babble */
char (*buffer)[8];
union {
@@ -1594,6 +1597,12 @@ static void hub_disconnect(struct usb_interface *intf)
if (hub->hdev->speed == USB_SPEED_HIGH)
highspeed_hubs--;
+#ifdef CONFIG_USB_HUB_DEVICE_PATH_REGULATOR
+ if (hub->regulator && !IS_ERR(hub->regulator)) {
+ regulator_disable(hub->regulator);
+ regulator_put(hub->regulator);
+ }
+#endif
usb_free_urb(hub->urb);
kfree(hub->ports);
kfree(hub->descriptor);
@@ -1609,6 +1618,9 @@ static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
struct usb_endpoint_descriptor *endpoint;
struct usb_device *hdev;
struct usb_hub *hub;
+#ifdef CONFIG_USB_HUB_DEVICE_PATH_REGULATOR
+ char *dev_path;
+#endif
desc = intf->cur_altsetting;
hdev = interface_to_usbdev(intf);
@@ -1692,6 +1704,18 @@ descriptor_error:
return -ENOMEM;
}
+#ifdef CONFIG_USB_HUB_DEVICE_PATH_REGULATOR
+ /* if a regulator is associated on our device_path, use it */
+ dev_path = kmalloc(MAX_DEV_PATH_SIZE, GFP_KERNEL);
+ if (!device_path_generate(&hdev->dev, dev_path, MAX_DEV_PATH_SIZE)) {
+ dev_info(&hdev->dev, "device_path: %s\n", dev_path);
+ hub->regulator = regulator_get(&hdev->dev, dev_path);
+ if (!IS_ERR(hub->regulator))
+ regulator_enable(hub->regulator);
+ }
+ kfree(dev_path);
+#endif
+
kref_init(&hub->kref);
INIT_LIST_HEAD(&hub->event_list);
hub->intfdev = &intf->dev;
--
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