USB: musb: support host/gadget role switching on Blackfin parts

Signed-off-by: Cliff Cai <cliff.cai@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 63 insertions, 6 deletions

diff --git a/drivers/usb/musb/blackfin.c b/drivers/usb/musb/blackfin.c
index eb4392f904e4..8052e7659ac8 100644
--- a/drivers/usb/musb/blackfin.c
+++ b/drivers/usb/musb/blackfin.c
@@ -170,6 +170,13 @@ static irqreturn_t blackfin_interrupt(int irq, void *__hci)
                 retval = musb_interrupt(musb);
         }
 
+        /* Start sampling ID pin, when plug is removed from MUSB */
+        if (is_otg_enabled(musb) && (musb->xceiv->state == OTG_STATE_B_IDLE
+                || musb->xceiv->state == OTG_STATE_A_WAIT_BCON)) {
+                mod_timer(&musb_conn_timer, jiffies + TIMER_DELAY);
+                musb->a_wait_bcon = TIMER_DELAY;
+        }
+
         spin_unlock_irqrestore(&musb->lock, flags);
 
         return retval;
@@ -180,6 +187,7 @@ static void musb_conn_timer_handler(unsigned long _musb)
         struct musb *musb = (void *)_musb;
         unsigned long flags;
         u16 val;
+        static u8 toggle;
 
         spin_lock_irqsave(&musb->lock, flags);
         switch (musb->xceiv->state) {
@@ -187,10 +195,44 @@ static void musb_conn_timer_handler(unsigned long _musb)
         case OTG_STATE_A_WAIT_BCON:
                 /* Start a new session */
                 val = musb_readw(musb->mregs, MUSB_DEVCTL);
+                val &= ~MUSB_DEVCTL_SESSION;
+                musb_writew(musb->mregs, MUSB_DEVCTL, val);
                 val |= MUSB_DEVCTL_SESSION;
                 musb_writew(musb->mregs, MUSB_DEVCTL, val);
+                /* Check if musb is host or peripheral. */
+                val = musb_readw(musb->mregs, MUSB_DEVCTL);
+
+                if (!(val & MUSB_DEVCTL_BDEVICE)) {
+                        gpio_set_value(musb->config->gpio_vrsel, 1);
+                        musb->xceiv->state = OTG_STATE_A_WAIT_BCON;
+                } else {
+                        gpio_set_value(musb->config->gpio_vrsel, 0);
+                        /* Ignore VBUSERROR and SUSPEND IRQ */
+                        val = musb_readb(musb->mregs, MUSB_INTRUSBE);
+                        val &= ~MUSB_INTR_VBUSERROR;
+                        musb_writeb(musb->mregs, MUSB_INTRUSBE, val);
 
+                        val = MUSB_INTR_SUSPEND | MUSB_INTR_VBUSERROR;
+                        musb_writeb(musb->mregs, MUSB_INTRUSB, val);
+                        if (is_otg_enabled(musb))
+                                musb->xceiv->state = OTG_STATE_B_IDLE;
+                        else
+                                musb_writeb(musb->mregs, MUSB_POWER, MUSB_POWER_HSENAB);
+                }
+                mod_timer(&musb_conn_timer, jiffies + TIMER_DELAY);
+                break;
+        case OTG_STATE_B_IDLE:
+
+                if (!is_peripheral_enabled(musb))
+                        break;
+                /* Start a new session.  It seems that MUSB needs taking
+                 * some time to recognize the type of the plug inserted?
+                 */
                 val = musb_readw(musb->mregs, MUSB_DEVCTL);
+                val |= MUSB_DEVCTL_SESSION;
+                musb_writew(musb->mregs, MUSB_DEVCTL, val);
+                val = musb_readw(musb->mregs, MUSB_DEVCTL);
+
                 if (!(val & MUSB_DEVCTL_BDEVICE)) {
                         gpio_set_value(musb->config->gpio_vrsel, 1);
                         musb->xceiv->state = OTG_STATE_A_WAIT_BCON;
@@ -205,12 +247,27 @@ static void musb_conn_timer_handler(unsigned long _musb)
                         val = MUSB_INTR_SUSPEND | MUSB_INTR_VBUSERROR;
                         musb_writeb(musb->mregs, MUSB_INTRUSB, val);
 
-                        val = MUSB_POWER_HSENAB;
-                        musb_writeb(musb->mregs, MUSB_POWER, val);
+                        /* Toggle the Soft Conn bit, so that we can response to
+                         * the inserting of either A-plug or B-plug.
+                         */
+                        if (toggle) {
+                                val = musb_readb(musb->mregs, MUSB_POWER);
+                                val &= ~MUSB_POWER_SOFTCONN;
+                                musb_writeb(musb->mregs, MUSB_POWER, val);
+                                toggle = 0;
+                        } else {
+                                val = musb_readb(musb->mregs, MUSB_POWER);
+                                val |= MUSB_POWER_SOFTCONN;
+                                musb_writeb(musb->mregs, MUSB_POWER, val);
+                                toggle = 1;
+                        }
+                        /* The delay time is set to 1/4 second by default,
+                         * shortening it, if accelerating A-plug detection
+                         * is needed in OTG mode.
+                         */
+                        mod_timer(&musb_conn_timer, jiffies + TIMER_DELAY / 4);
                 }
-                mod_timer(&musb_conn_timer, jiffies + TIMER_DELAY);
                 break;
-
         default:
                 DBG(1, "%s state not handled\n", otg_state_string(musb));
                 break;
@@ -222,7 +279,7 @@ static void musb_conn_timer_handler(unsigned long _musb)
 
 void musb_platform_enable(struct musb *musb)
 {
-        if (is_host_enabled(musb)) {
+        if (!is_otg_enabled(musb) && is_host_enabled(musb)) {
                 mod_timer(&musb_conn_timer, jiffies + TIMER_DELAY);
                 musb->a_wait_bcon = TIMER_DELAY;
         }
@@ -256,7 +313,7 @@ static int bfin_set_power(struct otg_transceiver *x, unsigned mA)
 
 void musb_platform_try_idle(struct musb *musb, unsigned long timeout)
 {
-        if (is_host_enabled(musb))
+        if (!is_otg_enabled(musb) && is_host_enabled(musb))
                 mod_timer(&musb_conn_timer, jiffies + TIMER_DELAY);
 }