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Commit ffc1d299 authored by Bin Liu's avatar Bin Liu Committed by Felipe Balbi
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usb: musb: add softconnect for host mode 



Add a debugfs interface - softconnect - for host mode to
connect/disconnect the devices without physically remove the
them.

This adds the capability to re-enumerate the devices which are
permanently mounted on the board with the MUSB controller
together.

Signed-off-by: default avatarBin Liu <b-liu@ti.com>
Signed-off-by: default avatarFelipe Balbi <balbi@ti.com>
parent d6d22922

drivers/usb/musb/musb_debugfs.c

+91 −0
Original line number Diff line number Diff line
@@ -245,6 +245,90 @@ static const struct file_operations musb_test_mode_fops = { 
	.release		= single_release,

};



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

{

	struct musb	*musb = s->private;

	u8		reg;

	int		connect;



	switch (musb->xceiv->otg->state) {

	case OTG_STATE_A_HOST:

	case OTG_STATE_A_WAIT_BCON:

		reg = musb_readb(musb->mregs, MUSB_DEVCTL);

		connect = reg & MUSB_DEVCTL_SESSION ? 1 : 0;

		break;

	default:

		connect = -1;

	}



	seq_printf(s, "%d\n", connect);



	return 0;

}



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

{

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

}



static ssize_t musb_softconnect_write(struct file *file,

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

{

	struct seq_file		*s = file->private_data;

	struct musb		*musb = s->private;

	char			buf[2];

	u8			reg;



	memset(buf, 0x00, sizeof(buf));



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

		return -EFAULT;



	if (!strncmp(buf, "0", 1)) {

		switch (musb->xceiv->otg->state) {

		case OTG_STATE_A_HOST:

			musb_root_disconnect(musb);

			reg = musb_readb(musb->mregs, MUSB_DEVCTL);

			reg &= ~MUSB_DEVCTL_SESSION;

			musb_writeb(musb->mregs, MUSB_DEVCTL, reg);

			break;

		default:

			break;

		}

	} else if (!strncmp(buf, "1", 1)) {

		switch (musb->xceiv->otg->state) {

		case OTG_STATE_A_WAIT_BCON:

			/*

			 * musb_save_context() called in musb_runtime_suspend()

			 * might cache devctl with SESSION bit cleared during

			 * soft-disconnect, so specifically set SESSION bit

			 * here to preserve it for musb_runtime_resume().

			 */

			musb->context.devctl |= MUSB_DEVCTL_SESSION;

			reg = musb_readb(musb->mregs, MUSB_DEVCTL);

			reg |= MUSB_DEVCTL_SESSION;

			musb_writeb(musb->mregs, MUSB_DEVCTL, reg);

			break;

		default:

			break;

		}

	}



	return count;

}



/*

 * In host mode, connect/disconnect the bus without physically

 * remove the devices.

 */

static const struct file_operations musb_softconnect_fops = {

	.open			= musb_softconnect_open,

	.write			= musb_softconnect_write,

	.read			= seq_read,

	.llseek			= seq_lseek,

	.release		= single_release,

};



int musb_init_debugfs(struct musb *musb)

{

	struct dentry		*root;
@@ -271,6 +355,13 @@ int musb_init_debugfs(struct musb *musb) 
		goto err1;

	}



	file = debugfs_create_file("softconnect", S_IRUGO | S_IWUSR,

			root, musb, &musb_softconnect_fops);

	if (!file) {

		ret = -ENOMEM;

		goto err1;

	}



	musb->debugfs_root = root;



	return 0;