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authorPeter Chen <peter.chen@freescale.com>2013-08-14 05:44:12 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-08-14 15:37:20 -0400
commit22fa84455a2a80566ead8efe4b5e629f2375da60 (patch)
treec77615fc9011a7ab64dbe17082f85f0ae1b36c3d
parenta107f8c505cd8606ae192d24c70b380e980fbe67 (diff)
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>
-rw-r--r--drivers/usb/chipidea/ci.h3
-rw-r--r--drivers/usb/chipidea/core.c32
-rw-r--r--drivers/usb/chipidea/otg.c4
3 files changed, 39 insertions, 0 deletions
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);
308 308
309u8 hw_port_test_get(struct ci_hdrc *ci); 309u8 hw_port_test_get(struct ci_hdrc *ci);
310 310
311int hw_wait_reg(struct ci_hdrc *ci, enum ci_hw_regs reg, u32 mask,
312 u32 value, unsigned int timeout_ms);
313
311#endif /* __DRIVERS_USB_CHIPIDEA_CI_H */ 314#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)
294 return 0; 294 return 0;
295} 295}
296 296
297/**
298 * hw_wait_reg: wait the register value
299 *
300 * Sometimes, it needs to wait register value before going on.
301 * Eg, when switch to device mode, the vbus value should be lower
302 * than OTGSC_BSV before connects to host.
303 *
304 * @ci: the controller
305 * @reg: register index
306 * @mask: mast bit
307 * @value: the bit value to wait
308 * @timeout_ms: timeout in millisecond
309 *
310 * This function returns an error code if timeout
311 */
312int hw_wait_reg(struct ci_hdrc *ci, enum ci_hw_regs reg, u32 mask,
313 u32 value, unsigned int timeout_ms)
314{
315 unsigned long elapse = jiffies + msecs_to_jiffies(timeout_ms);
316
317 while (hw_read(ci, reg, mask) != value) {
318 if (time_after(jiffies, elapse)) {
319 dev_err(ci->dev, "timeout waiting for %08x in %d\n",
320 mask, reg);
321 return -ETIMEDOUT;
322 }
323 msleep(20);
324 }
325
326 return 0;
327}
328
297static irqreturn_t ci_irq(int irq, void *data) 329static irqreturn_t ci_irq(int irq, void *data)
298{ 330{
299 struct ci_hdrc *ci = data; 331 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)
52 usb_gadget_vbus_disconnect(&ci->gadget); 52 usb_gadget_vbus_disconnect(&ci->gadget);
53} 53}
54 54
55#define CI_VBUS_STABLE_TIMEOUT_MS 5000
55static void ci_handle_id_switch(struct ci_hdrc *ci) 56static void ci_handle_id_switch(struct ci_hdrc *ci)
56{ 57{
57 enum ci_role role = ci_otg_role(ci); 58 enum ci_role role = ci_otg_role(ci);
@@ -61,6 +62,9 @@ static void ci_handle_id_switch(struct ci_hdrc *ci)
61 ci_role(ci)->name, ci->roles[role]->name); 62 ci_role(ci)->name, ci->roles[role]->name);
62 63
63 ci_role_stop(ci); 64 ci_role_stop(ci);
65 /* wait vbus lower than OTGSC_BSV */
66 hw_wait_reg(ci, OP_OTGSC, OTGSC_BSV, 0,
67 CI_VBUS_STABLE_TIMEOUT_MS);
64 ci_role_start(ci, role); 68 ci_role_start(ci, role);
65 } 69 }
66} 70}