leandrof/u-boot
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

sunxi: usbc: Wait for vbus to fall after disabling it

Browse Source 
When u-boot boots the board may be powering vbus, we turn off vbus in
sunxi_usbc_request_resources, if we are too quick with reading vusb-detect
after this we may see a residual charge and assume we've an external vusb
connected even though we do not. So when we see an external vusb wait a bit
and try again.

Without this when dealing with a pmic controller vbus and doing "reset" on
the u-boot console the musb host will only init once every other boot, because
the other boot it thinks an external vbus is present, this commit fixes this.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>
This commit is contained in:
Hans de Goede 2015-03-27 21:46:00 +01:00
parent 046ea8b390
commit a0e2b1b865
1 changed files with 13 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
arch/arm/cpu/armv7/sunxi/usbc.c
View File

@ -286,12 +286,23 @@ void sunxi_usbc_vbus_disable(int index)
int sunxi_usbc_vbus_detect(int index)
{
struct sunxi_usbc_hcd *sunxi_usbc = &sunxi_usbc_hcd[index];
int err;
int err, retries = 3;
if (sunxi_usbc->gpio_vbus_det == -1) {
eprintf("Error: invalid vbus detection pin\n");
return -1;
}
return gpio_get_value(sunxi_usbc->gpio_vbus_det);
err = gpio_get_value(sunxi_usbc->gpio_vbus_det);
/*
* Vbus may have been provided by the board and just been turned of
* some milliseconds ago on reset, what we're measuring then is a
* residual charge on Vbus, sleep a bit and try again.
*/
while (err > 0 && retries--) {
mdelay(100);
err = gpio_get_value(sunxi_usbc->gpio_vbus_det);
}
return err;
}