Hello.
Wang Hui wrote:
On omap2/3 series platforms, the musb can't raise id pin change
detection interrupt, so we must change otg mode through sysfs
interface manually. Currently when the musb is in B mode, if we
want musb to be changed to A mode, we should plug a mini-A cable
and then execute echo host > /sys/devices/platform/musb_hdrc/mode.
But if the musb is in A mode, we can't change it to B mode through
this method.
To solve this problem, add a process for sending end session request.
This process works like this, if the musb is in A mode, it will send
an end session request first, then it will follow original routine:
start a new session, during this session, it will identify whether
A or B is plugging in the socket, then it will init controller to A
or B mode according to its identification.
Usage: change cable as you desired,
change musb mode by #>echo host[peripheral] > /sys/devices/\
platform/musb_hdrc/mode,
then you will get required musb mode.
Signed-off-by: Wang Hui <Hui.Wang@xxxxxxxxxxxxx>
---
drivers/usb/musb/omap2430.c | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/drivers/usb/musb/omap2430.c b/drivers/usb/musb/omap2430.c
index 3fe1686..b02897e 100644
--- a/drivers/usb/musb/omap2430.c
+++ b/drivers/usb/musb/omap2430.c
@@ -194,6 +194,11 @@ int musb_platform_set_mode(struct musb *musb, u8 musb_mode)
{
u8 devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
+ if ((devctl & MUSB_DEVCTL_BDEVICE) == 0x0) {
+ devctl &= ~MUSB_DEVCTL_SESSION;
+ musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
+ }
+
devctl |= MUSB_DEVCTL_SESSION;
musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
The whole musb_platform_set_mode() seems to be implemented
incorrectly on OMAPs -- it shouldn't touch the DevCtl.Session bit. This
function should control the ID pin override instead -- if the controller
supports it. SRP must be initiated thru other means, i.e. 'srp' file in
sysfs.
WBR, Sergei
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