sh: intc: Add IRQ trigger bit field check

R-Mobile SoCs such as sh73a0 include PINT blocks in INTC
that come with 2-bit IRQ trigger support. Add code to make
sure the bit width is checked so 4-bit only modes like for
instance EDGE_BOTH will fail for PINT.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/drivers/sh/intc/chip.c b/drivers/sh/intc/chip.c
index 33b2ed4..e0ada37 100644
--- a/drivers/sh/intc/chip.c
+++ b/drivers/sh/intc/chip.c
@@ -202,11 +202,16 @@
 	if (!value)
 		return -EINVAL;
 
+	value &= ~SENSE_VALID_FLAG;
+
 	ihp = intc_find_irq(d->sense, d->nr_sense, irq);
 	if (ihp) {
+		/* PINT has 2-bit sense registers, should fail on EDGE_BOTH */
+		if (value >= (1 << _INTC_WIDTH(ihp->handle)))
+			return -EINVAL;
+
 		addr = INTC_REG(d, _INTC_ADDR_E(ihp->handle), 0);
-		intc_reg_fns[_INTC_FN(ihp->handle)](addr, ihp->handle,
-						    value & ~SENSE_VALID_FLAG);
+		intc_reg_fns[_INTC_FN(ihp->handle)](addr, ihp->handle, value);
 	}
 
 	return 0;