Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-09-29 03:13:05 +00:00
Code Issues Packages Projects Releases Wiki Activity

usb: chipidea: add wait vbus lower than OTGSC_BSV before role starts

Browse Source 
When the gadget role starts, we need to make sure the vbus is lower
than OTGSC_BSV, or there will be an vbus interrupt since we use
B_SESSION_VALID as vbus interrupt to indicate connect and disconnect.
When the host role starts, it may not be useful to wait vbus to lower
than OTGSC_BSV, but it can indicate some hardware problems like the
vbus is still higher than OTGSC_BSV after we disconnect to host some
time later (5000 milliseconds currently), which is obvious not correct.

Tested-by: Marek Vasut <marex@denx.de>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Peter Chen 2013-08-14 12:44:12 +03:00 committed by Greg Kroah-Hartman
parent a107f8c505
commit 22fa84455a
3 changed files with 39 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
drivers/usb/chipidea/ci.h
View File

@ -308,4 +308,7 @@ int hw_port_test_set(struct ci_hdrc *ci, u8 mode);
u8 hw_port_test_get(struct ci_hdrc *ci);
int hw_wait_reg(struct ci_hdrc *ci, enum ci_hw_regs reg, u32 mask,
u32 value, unsigned int timeout_ms);
#endif /* __DRIVERS_USB_CHIPIDEA_CI_H */

32
drivers/usb/chipidea/core.c
View File

@ -294,6 +294,38 @@ int hw_device_reset(struct ci_hdrc *ci, u32 mode)
return 0;
}
/**
* hw_wait_reg: wait the register value
*
* Sometimes, it needs to wait register value before going on.
* Eg, when switch to device mode, the vbus value should be lower
* than OTGSC_BSV before connects to host.
*
* @ci: the controller
* @reg: register index
* @mask: mast bit
* @value: the bit value to wait
* @timeout_ms: timeout in millisecond
*
* This function returns an error code if timeout
*/
int hw_wait_reg(struct ci_hdrc *ci, enum ci_hw_regs reg, u32 mask,
u32 value, unsigned int timeout_ms)
{
unsigned long elapse = jiffies + msecs_to_jiffies(timeout_ms);
while (hw_read(ci, reg, mask) != value) {
if (time_after(jiffies, elapse)) {
dev_err(ci->dev, "timeout waiting for %08x in %d\n",
mask, reg);
return -ETIMEDOUT;
}
msleep(20);
}
return 0;
}
static irqreturn_t ci_irq(int irq, void *data)
{
struct ci_hdrc *ci = data;

4
drivers/usb/chipidea/otg.c
View File

@ -52,6 +52,7 @@ void ci_handle_vbus_change(struct ci_hdrc *ci)
usb_gadget_vbus_disconnect(&ci->gadget);
}
#define CI_VBUS_STABLE_TIMEOUT_MS 5000
static void ci_handle_id_switch(struct ci_hdrc *ci)
{
enum ci_role role = ci_otg_role(ci);
@ -61,6 +62,9 @@ static void ci_handle_id_switch(struct ci_hdrc *ci)
ci_role(ci)->name, ci->roles[role]->name);
ci_role_stop(ci);
/* wait vbus lower than OTGSC_BSV */
hw_wait_reg(ci, OP_OTGSC, OTGSC_BSV, 0,
CI_VBUS_STABLE_TIMEOUT_MS);
ci_role_start(ci, role);
}
}