pinctrl: renesas: checker: Rework drive and bias pin iteration

The checker code to iterate over all drive strength and bias register
description items is cumbersome, due to the repeated calculation of
indices, and the use of hardcoded array sizes.  The latter was done
under the assumption they would never need to be changed, which turned
out to be false.

Increase readability by introducing helper macros to access drive
strength and bias register description items.
Increase maintainability by replacing hardcoded numbers by array sizes
calculated at compile-time.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/5051ae56a1388ccf2d283dfc9624de2991cce914.1650355619.git.geert+renesas@glider.be

drivers/pinctrl/renesas/core.c

@@ -1007,7 +1007,18 @@ static void __init sh_pfc_compare_groups(const char *drvname,
 static void __init sh_pfc_check_info(const struct sh_pfc_soc_info *info)
 {
 	const struct pinmux_drive_reg *drive_regs = info->drive_regs;
+#define drive_nfields	ARRAY_SIZE(drive_regs->fields)
+#define drive_ofs(i)	drive_regs[(i) / drive_nfields]
+#define drive_reg(i)	drive_ofs(i).reg
+#define drive_bit(i)	((i) % drive_nfields)
+#define drive_field(i)	drive_ofs(i).fields[drive_bit(i)]
 	const struct pinmux_bias_reg *bias_regs = info->bias_regs;
+#define bias_npins	ARRAY_SIZE(bias_regs->pins)
+#define bias_ofs(i)	bias_regs[(i) / bias_npins]
+#define bias_puen(i)	bias_ofs(i).puen
+#define bias_pud(i)	bias_ofs(i).pud
+#define bias_bit(i)	((i) % bias_npins)
+#define bias_pin(i)	bias_ofs(i).pins[bias_bit(i)]
 	const char *drvname = info->name;
 	unsigned int *refcnts;
 	unsigned int i, j, k;
@@ -1076,17 +1087,17 @@ static void __init sh_pfc_check_info(const struct sh_pfc_soc_info *info)
 			if (!drive_regs) {
 				sh_pfc_err_once(drive, "SH_PFC_PIN_CFG_DRIVE_STRENGTH flag set but drive_regs missing\n");
 			} else {
-				for (j = 0; drive_regs[j / 8].reg; j++) {
-					if (!drive_regs[j / 8].fields[j % 8].pin &&
-					    !drive_regs[j / 8].fields[j % 8].offset &&
-					    !drive_regs[j / 8].fields[j % 8].size)
+				for (j = 0; drive_reg(j); j++) {
+					if (!drive_field(j).pin &&
+					    !drive_field(j).offset &&
+					    !drive_field(j).size)
 						continue;
 
-					if (drive_regs[j / 8].fields[j % 8].pin == pin->pin)
+					if (drive_field(j).pin == pin->pin)
 						break;
 				}
 
-				if (!drive_regs[j / 8].reg)
+				if (!drive_reg(j))
 					sh_pfc_err("pin %s: SH_PFC_PIN_CFG_DRIVE_STRENGTH flag set but not in drive_regs\n",
 						   pin->name);
 			}
@@ -1164,20 +1175,17 @@ static void __init sh_pfc_check_info(const struct sh_pfc_soc_info *info)
 	for (i = 0; drive_regs && drive_regs[i].reg; i++)
 		sh_pfc_check_drive_reg(info, &drive_regs[i]);
 
-	for (i = 0; drive_regs && drive_regs[i / 8].reg; i++) {
-		if (!drive_regs[i / 8].fields[i % 8].pin &&
-		    !drive_regs[i / 8].fields[i % 8].offset &&
-		    !drive_regs[i / 8].fields[i % 8].size)
+	for (i = 0; drive_regs && drive_reg(i); i++) {
+		if (!drive_field(i).pin && !drive_field(i).offset &&
+		    !drive_field(i).size)
 			continue;
 
 		for (j = 0; j < i; j++) {
-			if (drive_regs[i / 8].fields[i % 8].pin ==
-			    drive_regs[j / 8].fields[j % 8].pin &&
-			    drive_regs[j / 8].fields[j % 8].offset &&
-			    drive_regs[j / 8].fields[j % 8].size) {
-				sh_pfc_err("drive_reg 0x%x:%u/0x%x:%u: pin conflict\n",
-					   drive_regs[i / 8].reg, i % 8,
-					   drive_regs[j / 8].reg, j % 8);
+			if (drive_field(i).pin == drive_field(j).pin &&
+			    drive_field(j).offset && drive_field(j).size) {
+				sh_pfc_err("drive_reg 0x%x:%zu/0x%x:%zu: pin conflict\n",
+					   drive_reg(i), drive_bit(i),
+					   drive_reg(j), drive_bit(j));
 			}
 		}
 	}
@@ -1186,26 +1194,23 @@ static void __init sh_pfc_check_info(const struct sh_pfc_soc_info *info)
 	for (i = 0; bias_regs && (bias_regs[i].puen || bias_regs[i].pud); i++)
 		sh_pfc_check_bias_reg(info, &bias_regs[i]);
 
-	for (i = 0; bias_regs &&
-		    (bias_regs[i / 32].puen || bias_regs[i / 32].pud); i++) {
-		if (bias_regs[i / 32].pins[i % 32] == SH_PFC_PIN_NONE)
+	for (i = 0; bias_regs && (bias_puen(i) || bias_pud(i)); i++) {
+		if (bias_pin(i) == SH_PFC_PIN_NONE)
 			continue;
 
 		for (j = 0; j < i; j++) {
-			if (bias_regs[i / 32].pins[i % 32] !=
-			    bias_regs[j / 32].pins[j % 32])
+			if (bias_pin(i) != bias_pin(j))
 				continue;
 
-			if (bias_regs[i / 32].puen && bias_regs[j / 32].puen)
-				sh_pfc_err("bias_reg 0x%x:%u/0x%x:%u: pin conflict\n",
-					   bias_regs[i / 32].puen, i % 32,
-					   bias_regs[j / 32].puen, j % 32);
-			if (bias_regs[i / 32].pud && bias_regs[j / 32].pud)
-				sh_pfc_err("bias_reg 0x%x:%u/0x%x:%u: pin conflict\n",
-					   bias_regs[i / 32].pud, i % 32,
-					   bias_regs[j / 32].pud, j % 32);
+			if (bias_puen(i) && bias_puen(j))
+				sh_pfc_err("bias_reg 0x%x:%zu/0x%x:%zu: pin conflict\n",
+					   bias_puen(i), bias_bit(i),
+					   bias_puen(j), bias_bit(j));
+			if (bias_pud(i) && bias_pud(j))
+				sh_pfc_err("bias_reg 0x%x:%zu/0x%x:%zu: pin conflict\n",
+					   bias_pud(i), bias_bit(i),
+					   bias_pud(j), bias_bit(j));
 		}
-
 	}
 
 	/* Check ioctrl registers */