irqchip/irq-pruss-intc: Use macros for operations on CMR and HMR

The PRUSS INTC configuration code is currently using hard-coded numbers
directly for performing arithmatic operations on the Channel Map Registers
(CMRs) and Host Interrupt Map Registers (HMRs). Introduce and replace
these numbers with human readable macros.

While at this, use the modulo operator instead of bitwise-and for
the bit offset computation for the events and channels in CMR and
HMR registers.

Signed-off-by: Suman Anna <s-anna@ti.com>

drivers/irqchip/irq-pruss-intc.c

@@ -52,6 +52,16 @@
 #define PRU_INTC_HINLR(x)	(0x1100 + (x) * 4)
 #define PRU_INTC_HIER		0x1500
 
+/* CMR register bit-field macros */
+#define CMR_EVT_MAP_MASK	0xf
+#define CMR_EVT_MAP_BITS	8
+#define CMR_EVT_PER_REG		4
+
+/* HMR register bit-field macros */
+#define HMR_CH_MAP_MASK		0xf
+#define HMR_CH_MAP_BITS		8
+#define HMR_CH_PER_REG		4
+
 /* HIPIR register bit-fields */
 #define INTC_HIPIR_NONE_HINT	0x80000000
 
@@ -189,9 +199,9 @@ int pruss_intc_configure(struct pruss *pruss,
 
 		intc->config_map.sysev_to_ch[i] = ch;
 
-		idx = i / 4;
+		idx = i / CMR_EVT_PER_REG;
 		val = pruss_intc_read_reg(intc, PRU_INTC_CMR(idx));
-		val |= ch << ((i & 3) * 8);
+		val |= ch << ((i % CMR_EVT_PER_REG) * CMR_EVT_MAP_BITS);
 		pruss_intc_write_reg(intc, PRU_INTC_CMR(idx), val);
 		sysevt_mask |= BIT_ULL(i);
 		ch_mask |= BIT(ch);
@@ -228,10 +238,10 @@ int pruss_intc_configure(struct pruss *pruss,
 
 		intc->config_map.ch_to_host[i] = host;
 
-		idx = i / 4;
+		idx = i / HMR_CH_PER_REG;
 
 		val = pruss_intc_read_reg(intc, PRU_INTC_HMR(idx));
-		val |= host << ((i & 3) * 8);
+		val |= host << ((i % HMR_CH_PER_REG) * HMR_CH_MAP_BITS);
 		pruss_intc_write_reg(intc, PRU_INTC_HMR(idx), val);
 
 		ch_mask |= BIT(i);
@@ -427,14 +437,15 @@ static int pruss_intc_irq_set_affinity(struct irq_data *data,
 	}
 
 	/* find programmed channel */
-	ch = pruss_intc_read_reg(intc, PRU_INTC_CMR(data->hwirq / 4));
-	ch >>= (data->hwirq % 4) * 8;
-	ch &= 0xf;
+	ch = pruss_intc_read_reg(intc,
+				 PRU_INTC_CMR(data->hwirq / CMR_EVT_PER_REG));
+	ch >>= (data->hwirq % CMR_EVT_PER_REG) * CMR_EVT_MAP_BITS;
+	ch &= CMR_EVT_MAP_MASK;
 
 	/* find programmed host interrupt */
-	host = pruss_intc_read_reg(intc, PRU_INTC_HMR(ch / 4));
-	host >>= (ch % 4) * 8;
-	host &= 0xf;
+	host = pruss_intc_read_reg(intc, PRU_INTC_HMR(ch / HMR_CH_MAP_BITS));
+	host >>= (ch % HMR_CH_PER_REG) * HMR_CH_MAP_BITS;
+	host &= HMR_CH_MAP_MASK;
 
 	/* check programmed configuration for sanity */
 	if (ch != sch || host != shost) {