diff options
author | Peter Chen <peter.chen@freescale.com> | 2013-08-14 09:44:12 (GMT) |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-08-14 19:37:20 (GMT) |
commit | 22fa84455a2a80566ead8efe4b5e629f2375da60 (patch) | |
tree | c77615fc9011a7ab64dbe17082f85f0ae1b36c3d /drivers/usb/chipidea | |
parent | a107f8c505cd8606ae192d24c70b380e980fbe67 (diff) | |
download | linux-22fa84455a2a80566ead8efe4b5e629f2375da60.tar.xz |
usb: chipidea: add wait vbus lower than OTGSC_BSV before role starts
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>
Diffstat (limited to 'drivers/usb/chipidea')
-rw-r--r-- | drivers/usb/chipidea/ci.h | 3 | ||||
-rw-r--r-- | drivers/usb/chipidea/core.c | 32 | ||||
-rw-r--r-- | drivers/usb/chipidea/otg.c | 4 |
3 files changed, 39 insertions, 0 deletions
diff --git a/drivers/usb/chipidea/ci.h b/drivers/usb/chipidea/ci.h index 3160363..1c94fc5 100644 --- a/drivers/usb/chipidea/ci.h +++ b/drivers/usb/chipidea/ci.h @@ -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 */ diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c index c95e098..9462640 100644 --- a/drivers/usb/chipidea/core.c +++ b/drivers/usb/chipidea/core.c @@ -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; diff --git a/drivers/usb/chipidea/otg.c b/drivers/usb/chipidea/otg.c index 7f37484..39bd7ec 100644 --- a/drivers/usb/chipidea/otg.c +++ b/drivers/usb/chipidea/otg.c @@ -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); } } |