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Commit 22fa8445 authored by Peter Chen's avatar Peter Chen Committed by Greg Kroah-Hartman
Browse files

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: default avatarMarek Vasut <marex@denx.de>
Signed-off-by: default avatarPeter Chen <peter.chen@freescale.com>
Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a107f8c5

drivers/usb/chipidea/ci.h

+3 −0
Original line number Diff line number Diff line
@@ -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 */

drivers/usb/chipidea/core.c

+32 −0
Original line number Diff line number Diff line
@@ -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;

drivers/usb/chipidea/otg.c

+4 −0
Original line number Diff line number Diff line
@@ -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);

	}

}