On Thursday 21 January 2016 20:21:13 Tony Lindgren wrote: > * joerg Reisenweber <joerg@xxxxxxxxxxxx> [160121 10:45]: > > On Thu 21 January 2016 09:41:46 Tony Lindgren wrote: > > > Then for supporting the USB host mode.. We should add regulator > > > support to the USB PHY driver so if the ID pin is grounded, the > > > PHY driver enables the VBUS regulator. That too seems to need > > > some coordination between the drivers/phy/phy-twl4030-usb.c and > > > 1707 driver if the ID pin interrupt is only detected in > > > drivers/phy/phy-twl4030-usb.c. > > > > Note that, while this is probably a good thing to do, it needs to > > be sufficiently loose coupling to allow user to 'intercept' this > > VBOOS regulator enabling and instead allow device charging while > > in externally powered hostmode. There's even a spec for this in > > USB-docs-foo iirc, something along a certain resistor value on ID > > to GND - alas I guess the twl4030 is not capable to detect such > > sophisticated signaling, and anyway it's always desirable to allow > > user to manually override the VBOOST and enable VBUS-charging > > while in hostmode. > > OK, I think this is what's happening with the Motorola LapDock BTW. > It always feeds the VBUS, well most of the time. Do you have some > pointer to the "certain resistor value on ID to GND" spec? Is it > maybe part of the carkit related parts of the USB spec? > > > On N900 the situation is even more complex since the 1707 doesn't > > support genuine ID detection, neither does it support emulated ID > > grounding. And there's no other method than a ID=GND message from > > PHY to musb core to make the musb core state engine transfer into > > proper hostmode. Thus my H-E-N hostmode botch abuses debug flags > > to force the musb core into a "emulated" hostmode and this mode > > doesn't support USB speed detection. Thus speed settings are > > forced onto musb core and PHY by software, and the musb core speed > > bits are only effective before session enabled. > > Bottom line: you need VBUS to try and negotiate speed with the > > attached device in hostmode, but to actually set this speed you > > detected by software means, you need to disable and discharge VBUS > > again, or musb core won't care about the speed you set. To be > > utterly clear: unconditional enabling of VBUS in ID=GND won't > > work. > > > > This is quite complex and it's questionable if it could get handled > > reasonably in kernel space. *Very* N900 specific niche solution, > > I'd not think it's suited for upstreaming. > > Yeah OK. I think we should be able to support the aux VBUS regulator > part with mainline kernel though. > > Regards, > > Tony Hello, attached patch for musb debugfs adds option to force both hostmode with speed. It is just example, I tested only compilation. Something like that will be needed for usb host mode on Nokia N900. -- Pali Rohár pali.rohar@xxxxxxxxx
From fd67b58e3538c0732750ecad915cde736da099dc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali.rohar@xxxxxxxxx>
Date: Sat, 9 Jan 2016 16:57:59 +0100
Subject: [PATCH] musb: debugfs: Add support in testmode for forcing host mode
together with speed
---
drivers/usb/musb/musb_debugfs.c | 44 +++++++++++++++++++++++++--------------
1 file changed, 28 insertions(+), 16 deletions(-)
diff --git a/drivers/usb/musb/musb_debugfs.c b/drivers/usb/musb/musb_debugfs.c
index 9b22d94..62c13a2 100644
--- a/drivers/usb/musb/musb_debugfs.c
+++ b/drivers/usb/musb/musb_debugfs.c
@@ -147,28 +147,34 @@ static int musb_test_mode_show(struct seq_file *s, void *unused)
test = musb_readb(musb->mregs, MUSB_TESTMODE);
- if (test & MUSB_TEST_FORCE_HOST)
+ if (test & (MUSB_TEST_FORCE_HOST | MUSB_TEST_FORCE_FS))
+ seq_printf(s, "force host full-speed\n");
+
+ else if (test & (MUSB_TEST_FORCE_HOST | MUSB_TEST_FORCE_HS))
+ seq_printf(s, "force host high-speed\n");
+
+ else if (test & MUSB_TEST_FORCE_HOST)
seq_printf(s, "force host\n");
- if (test & MUSB_TEST_FIFO_ACCESS)
+ else if (test & MUSB_TEST_FIFO_ACCESS)
seq_printf(s, "fifo access\n");
- if (test & MUSB_TEST_FORCE_FS)
+ else if (test & MUSB_TEST_FORCE_FS)
seq_printf(s, "force full-speed\n");
- if (test & MUSB_TEST_FORCE_HS)
+ else if (test & MUSB_TEST_FORCE_HS)
seq_printf(s, "force high-speed\n");
- if (test & MUSB_TEST_PACKET)
+ else if (test & MUSB_TEST_PACKET)
seq_printf(s, "test packet\n");
- if (test & MUSB_TEST_K)
+ else if (test & MUSB_TEST_K)
seq_printf(s, "test K\n");
- if (test & MUSB_TEST_J)
+ else if (test & MUSB_TEST_J)
seq_printf(s, "test J\n");
- if (test & MUSB_TEST_SE0_NAK)
+ else if (test & MUSB_TEST_SE0_NAK)
seq_printf(s, "test SE0 NAK\n");
return 0;
@@ -206,30 +212,36 @@ static ssize_t musb_test_mode_write(struct file *file,
if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
return -EFAULT;
- if (strstarts(buf, "force host"))
+ if (strstarts(buf, "force host full-speed"))
+ test = MUSB_TEST_FORCE_HOST | MUSB_TEST_FORCE_FS;
+
+ else if (strstarts(buf, "force host high-speed"))
+ test = MUSB_TEST_FORCE_HOST | MUSB_TEST_FORCE_HS;
+
+ else if (strstarts(buf, "force host"))
test = MUSB_TEST_FORCE_HOST;
- if (strstarts(buf, "fifo access"))
+ else if (strstarts(buf, "fifo access"))
test = MUSB_TEST_FIFO_ACCESS;
- if (strstarts(buf, "force full-speed"))
+ else if (strstarts(buf, "force full-speed"))
test = MUSB_TEST_FORCE_FS;
- if (strstarts(buf, "force high-speed"))
+ else if (strstarts(buf, "force high-speed"))
test = MUSB_TEST_FORCE_HS;
- if (strstarts(buf, "test packet")) {
+ else if (strstarts(buf, "test packet")) {
test = MUSB_TEST_PACKET;
musb_load_testpacket(musb);
}
- if (strstarts(buf, "test K"))
+ else if (strstarts(buf, "test K"))
test = MUSB_TEST_K;
- if (strstarts(buf, "test J"))
+ else if (strstarts(buf, "test J"))
test = MUSB_TEST_J;
- if (strstarts(buf, "test SE0 NAK"))
+ else if (strstarts(buf, "test SE0 NAK"))
test = MUSB_TEST_SE0_NAK;
musb_writeb(musb->mregs, MUSB_TESTMODE, test);
--
1.7.9.5
Attachment:
signature.asc
Description: This is a digitally signed message part.
