From 22fa84455a2a80566ead8efe4b5e629f2375da60 Mon Sep 17 00:00:00 2001 From: Peter Chen Date: Wed, 14 Aug 2013 12:44:12 +0300 Subject: [PATCH] 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 Signed-off-by: Peter Chen Signed-off-by: Alexander Shishkin Signed-off-by: Greg Kroah-Hartman --- drivers/usb/chipidea/ci.h | 3 +++ drivers/usb/chipidea/core.c | 32 ++++++++++++++++++++++++++++++++ drivers/usb/chipidea/otg.c | 4 ++++ 3 files changed, 39 insertions(+) diff --git a/drivers/usb/chipidea/ci.h b/drivers/usb/chipidea/ci.h index 316036392e11..1c94fc5257f4 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 c95e098fe9db..94626409559a 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 7f37484ca362..39bd7ec8bf75 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); } } -- 2.30.2