[RFC v4 12/14] EXAMPLE CODE: usb: hub: Power sequence the ports on activation

Krzysztof Kozlowski
2016-06-09T09:44:29Z

The autodetection of attached USB device might not work on certain
boards where the power is delivered externally. These devices also might
require a hard reset. Use pwrseq for that in USB hub.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
---
drivers/usb/core/hub.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index c421745b84aa..46d9f9aedacc 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -26,6 +26,7 @@
#include <linux/mutex.h>
#include <linux/random.h>
#include <linux/pm_qos.h>
+#include <linux/pwrseq.h>

#include <asm/uaccess.h>
#include <asm/byteorder.h>
@@ -1663,6 +1664,15 @@ static int hub_configure(struct usb_hub *hub,

usb_hub_adjust_deviceremovable(hdev, hub->descriptor);

+ /* FIXME: When do the pre-power-on? */
+ /*
+ for (i = 0; i < maxchild; i++)
+ pwrseq_pre_power_on(hub->ports[i]->pwrseq);
+ */
+
+ for (i = 0; i < maxchild; i++)
+ pwrseq_post_power_on(hub->ports[i]->pwrseq);
+
hub_activate(hub, HUB_INIT);
return 0;

--
1.9.1