usb: musb: core: improve musb_interrupt() a bit

instead of using manually spelled out bit-shits
and iterate over each of the 16-bits (one for
each endpoint) on each direction, we can make use
of for_each_set_bit() which internally uses
find_first_bit().

This makes the code slightly more readable while
also making we only iterate over bits which are
actually set.

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

1 files changed, 24 insertions, 28 deletions

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 461bfe8efcf2..e59ae7395ba8 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -1587,9 +1587,12 @@ static int musb_core_init(u16 musb_type, struct musb *musb)
 irqreturn_t musb_interrupt(struct musb *musb)
 {
         irqreturn_t     retval = IRQ_NONE;
+        unsigned long   status;
+        unsigned long   epnum;
         u8              devctl;
-        int             ep_num;
-        u32             reg;
+
+        if (!musb->int_usb && !musb->int_tx && !musb->int_rx)
+                return IRQ_NONE;
 
         devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
 
@@ -1618,43 +1621,36 @@ irqreturn_t musb_interrupt(struct musb *musb)
          */
 
         if (musb->int_usb)
-                retval |= musb_stage0_irq(musb, musb->int_usb,
-                                devctl);
+                retval |= musb_stage0_irq(musb, musb->int_usb, devctl);
 
         if (musb->int_tx & 1) {
                 if (is_host_active(musb))
                         retval |= musb_h_ep0_irq(musb);
                 else
                         retval |= musb_g_ep0_irq(musb);
+
+                /* we have just handled endpoint 0 IRQ, clear it */
+                musb->int_tx &= ~BIT(0);
         }
 
-        reg = musb->int_tx >> 1;
-        ep_num = 1;
-        while (reg) {
-                if (reg & 1) {
-                        retval = IRQ_HANDLED;
-                        if (is_host_active(musb))
-                                musb_host_tx(musb, ep_num);
-                        else
-                                musb_g_tx(musb, ep_num);
-                }
-                reg >>= 1;
-                ep_num++;
+        status = musb->int_tx;
+
+        for_each_set_bit(epnum, &status, 16) {
+                retval = IRQ_HANDLED;
+                if (is_host_active(musb))
+                        musb_host_tx(musb, epnum);
+                else
+                        musb_g_tx(musb, epnum);
         }
 
-        reg = musb->int_rx >> 1;
-        ep_num = 1;
-        while (reg) {
-                if (reg & 1) {
-                        retval = IRQ_HANDLED;
-                        if (is_host_active(musb))
-                                musb_host_rx(musb, ep_num);
-                        else
-                                musb_g_rx(musb, ep_num);
-                }
+        status = musb->int_rx;
 
-                reg >>= 1;
-                ep_num++;
+        for_each_set_bit(epnum, &status, 16) {
+                retval = IRQ_HANDLED;
+                if (is_host_active(musb))
+                        musb_host_rx(musb, epnum);
+                else
+                        musb_g_rx(musb, epnum);
         }
 
         return retval;