usb: musb: ux500: implement musb_set_vbus

Add ux500_musb_set_vbus() implementation for ux500.

This is based on the version originally developed inside ST-Ericsson.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Fabio Baltieri <fabio.baltieri@linaro.org>
[ balbi@ti.com: fix a build error due to
	missing otg_state_string() ]

Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/musb/ux500.c b/drivers/usb/musb/ux500.c
index 13a3929..0332fcd 100644 (file)
--- a/drivers/usb/musb/ux500.c
+++ b/drivers/usb/musb/ux500.c
@@ -36,6 +36,68 @@ struct ux500_glue {
 };
 #define glue_to_musb(g)        platform_get_drvdata(g->musb)
 
+static void ux500_musb_set_vbus(struct musb *musb, int is_on)
+{
+       u8            devctl;
+       unsigned long timeout = jiffies + msecs_to_jiffies(1000);
+       /* HDRC controls CPEN, but beware current surges during device
+        * connect.  They can trigger transient overcurrent conditions
+        * that must be ignored.
+        */
+
+       devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
+
+       if (is_on) {
+               if (musb->xceiv->state == OTG_STATE_A_IDLE) {
+                       /* start the session */
+                       devctl |= MUSB_DEVCTL_SESSION;
+                       musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
+                       /*
+                        * Wait for the musb to set as A device to enable the
+                        * VBUS
+                        */
+                       while (musb_readb(musb->mregs, MUSB_DEVCTL) & 0x80) {
+
+                               if (time_after(jiffies, timeout)) {
+                                       dev_err(musb->controller,
+                                       "configured as A device timeout");
+                                       break;
+                               }
+                       }
+
+               } else {
+                       musb->is_active = 1;
+                       musb->xceiv->otg->default_a = 1;
+                       musb->xceiv->state = OTG_STATE_A_WAIT_VRISE;
+                       devctl |= MUSB_DEVCTL_SESSION;
+                       MUSB_HST_MODE(musb);
+               }
+       } else {
+               musb->is_active = 0;
+
+               /* NOTE: we're skipping A_WAIT_VFALL -> A_IDLE and jumping
+                * right to B_IDLE...
+                */
+               musb->xceiv->otg->default_a = 0;
+               devctl &= ~MUSB_DEVCTL_SESSION;
+               MUSB_DEV_MODE(musb);
+       }
+       musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
+
+       /*
+        * Devctl values will be updated after vbus goes below
+        * session_valid. The time taken depends on the capacitance
+        * on VBUS line. The max discharge time can be upto 1 sec
+        * as per the spec. Typically on our platform, it is 200ms
+        */
+       if (!is_on)
+               mdelay(200);
+
+       dev_dbg(musb->controller, "VBUS %s, devctl %02x\n",
+               usb_otg_state_string(musb->xceiv->state),
+               musb_readb(musb->mregs, MUSB_DEVCTL));
+}
+
 static irqreturn_t ux500_musb_interrupt(int irq, void *__hci)
 {
        unsigned long   flags;
@@ -79,6 +141,8 @@ static int ux500_musb_exit(struct musb *musb)
 static const struct musb_platform_ops ux500_ops = {
        .init           = ux500_musb_init,
        .exit           = ux500_musb_exit,
+
+       .set_vbus       = ux500_musb_set_vbus,
 };
 
 static int ux500_probe(struct platform_device *pdev)