Commit 138801aa authored by Felipe Balbi's avatar Felipe Balbi
Browse files

usb: dwc3: gadget: allow Link state changes via debugfs 



This is very useful for low level link testing where
we might not have a USB Host stack, only a scope to
verify signal integrity.

Signed-off-by: default avatarFelipe Balbi <balbi@ti.com>
parent 8598bde7

drivers/usb/dwc3/debugfs.c

+110 −0
Original line number Diff line number Diff line
@@ -549,6 +549,109 @@ static const struct file_operations dwc3_testmode_fops = { 
	.release		= single_release,

};



static int dwc3_link_state_show(struct seq_file *s, void *unused)

{

	struct dwc3		*dwc = s->private;

	unsigned long		flags;

	enum dwc3_link_state	state;

	u32			reg;



	spin_lock_irqsave(&dwc->lock, flags);

	reg = dwc3_readl(dwc->regs, DWC3_DSTS);

	state = DWC3_DSTS_USBLNKST(reg);

	spin_unlock_irqrestore(&dwc->lock, flags);



	switch (state) {

	case DWC3_LINK_STATE_U0:

		seq_printf(s, "U0\n");

		break;

	case DWC3_LINK_STATE_U1:

		seq_printf(s, "U1\n");

		break;

	case DWC3_LINK_STATE_U2:

		seq_printf(s, "U2\n");

		break;

	case DWC3_LINK_STATE_U3:

		seq_printf(s, "U3\n");

		break;

	case DWC3_LINK_STATE_SS_DIS:

		seq_printf(s, "SS.Disabled\n");

		break;

	case DWC3_LINK_STATE_RX_DET:

		seq_printf(s, "Rx.Detect\n");

		break;

	case DWC3_LINK_STATE_SS_INACT:

		seq_printf(s, "SS.Inactive\n");

		break;

	case DWC3_LINK_STATE_POLL:

		seq_printf(s, "Poll\n");

		break;

	case DWC3_LINK_STATE_RECOV:

		seq_printf(s, "Recovery\n");

		break;

	case DWC3_LINK_STATE_HRESET:

		seq_printf(s, "HRESET\n");

		break;

	case DWC3_LINK_STATE_CMPLY:

		seq_printf(s, "Compliance\n");

		break;

	case DWC3_LINK_STATE_LPBK:

		seq_printf(s, "Loopback\n");

		break;

	default:

		seq_printf(s, "UNKNOWN %d\n", reg);

	}



	return 0;

}



static int dwc3_link_state_open(struct inode *inode, struct file *file)

{

	return single_open(file, dwc3_link_state_show, inode->i_private);

}



static ssize_t dwc3_link_state_write(struct file *file,

		const char __user *ubuf, size_t count, loff_t *ppos)

{

	struct seq_file		*s = file->private_data;

	struct dwc3		*dwc = s->private;

	unsigned long		flags;

	enum dwc3_link_state	state = 0;

	char			buf[32];



	if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))

		return -EFAULT;



	if (!strncmp(buf, "SS.Disabled", 11))

		state = DWC3_LINK_STATE_SS_DIS;

	else if (!strncmp(buf, "Rx.Detect", 9))

		state = DWC3_LINK_STATE_RX_DET;

	else if (!strncmp(buf, "SS.Inactive", 11))

		state = DWC3_LINK_STATE_SS_INACT;

	else if (!strncmp(buf, "Recovery", 8))

		state = DWC3_LINK_STATE_RECOV;

	else if (!strncmp(buf, "Compliance", 10))

		state = DWC3_LINK_STATE_CMPLY;

	else if (!strncmp(buf, "Loopback", 8))

		state = DWC3_LINK_STATE_LPBK;

	else

		return -EINVAL;



	spin_lock_irqsave(&dwc->lock, flags);

	dwc3_gadget_set_link_state(dwc, state);

	spin_unlock_irqrestore(&dwc->lock, flags);



	return count;

}



static const struct file_operations dwc3_link_state_fops = {

	.open			= dwc3_link_state_open,

	.write			= dwc3_link_state_write,

	.read			= seq_read,

	.llseek			= seq_lseek,

	.release		= single_release,

};



int __devinit dwc3_debugfs_init(struct dwc3 *dwc)

{

	struct dentry		*root;
@@ -584,6 +687,13 @@ int __devinit dwc3_debugfs_init(struct dwc3 *dwc) 
		goto err1;

	}



	file = debugfs_create_file("link_state", S_IRUGO | S_IWUSR, root,

			dwc, &dwc3_link_state_fops);

	if (IS_ERR(file)) {

		ret = PTR_ERR(file);

		goto err1;

	}



	return 0;



err1:

drivers/usb/dwc3/gadget.c

+1 −1
Original line number Diff line number Diff line
@@ -117,7 +117,7 @@ int dwc3_gadget_set_link_state(struct dwc3 *dwc, enum dwc3_link_state state) 
		if (DWC3_DSTS_USBLNKST(reg) == state)

			return 0;



		usleep_range(500, 1500);

		udelay(500);

	}



	dev_vdbg(dwc->dev, "link state change request timed out\n");