From ffc1d299aa836f540a20302e9f22120639ea2944 Mon Sep 17 00:00:00 2001 From: Bin Liu Date: Tue, 24 Mar 2015 15:19:56 -0500 Subject: 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: Bin Liu Signed-off-by: Felipe Balbi --- drivers/usb/musb/musb_debugfs.c | 91 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) (limited to 'drivers/usb/musb') diff --git a/drivers/usb/musb/musb_debugfs.c b/drivers/usb/musb/musb_debugfs.c index 04382ec31d3f..9b22d946c089 100644 --- a/drivers/usb/musb/musb_debugfs.c +++ b/drivers/usb/musb/musb_debugfs.c @@ -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; -- cgit v1.2.3