pinctrl: keembay: rework loops looking for groups names

Make the outer loop iterate over functions as that's the real subject.
This simplifies code (and reduces amount of lines of code) as allocating
memory for names doesn't require extra checks anymore.

While at it use local "group_names" variable. The plan for
"struct function_desc" is to make its "group_names" /double/ const. That
will allow drivers to use it with static const data.

This keembay "group_names" change is required to avoid:
drivers/pinctrl/pinctrl-keembay.c: In function 'keembay_add_functions':
drivers/pinctrl/pinctrl-keembay.c:1594:8: warning: assignment discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
 1594 |    grp = func->group_names;
      |        ^
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Link: https://lore.kernel.org/r/20211216162206.8027-3-zajec5@gmail.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-keembay.c

@@ -1555,58 +1555,42 @@ static int keembay_pinctrl_reg(struct keembay_pinctrl *kpc,  struct device *dev)
 }
 
 static int keembay_add_functions(struct keembay_pinctrl *kpc,
-				 struct function_desc *function)
+				 struct function_desc *functions)
 {
 	unsigned int i;
 
 	/* Assign the groups for each function */
-	for (i = 0; i < kpc->npins; i++) {
-		const struct pinctrl_pin_desc *pdesc = keembay_pins + i;
-		struct keembay_mux_desc *mux = pdesc->drv_data;
-
-		while (mux->name) {
-			struct function_desc *func;
-			const char **grp;
-			size_t grp_size;
-			u32 j, grp_num;
-
-			for (j = 0; j < kpc->nfuncs; j++) {
-				if (!strcmp(mux->name, function[j].name))
-					break;
-			}
-
-			if (j == kpc->nfuncs)
-				return -EINVAL;
-
-			func = function + j;
-			grp_num = func->num_group_names;
-			grp_size = sizeof(*func->group_names);
-
-			if (!func->group_names) {
-				func->group_names = devm_kcalloc(kpc->dev,
-								 grp_num,
-								 grp_size,
-								 GFP_KERNEL);
-				if (!func->group_names)
-					return -ENOMEM;
+	for (i = 0; i < kpc->nfuncs; i++) {
+		struct function_desc *func = &functions[i];
+		const char **group_names;
+		unsigned int grp_idx = 0;
+		int j;
+
+		group_names = devm_kcalloc(kpc->dev, func->num_group_names,
+					   sizeof(*group_names), GFP_KERNEL);
+		if (!group_names)
+			return -ENOMEM;
+
+		for (j = 0; j < kpc->npins; j++) {
+			const struct pinctrl_pin_desc *pdesc = &keembay_pins[j];
+			struct keembay_mux_desc *mux;
+
+			for (mux = pdesc->drv_data; mux->name; mux++) {
+				if (!strcmp(mux->name, func->name))
+					group_names[grp_idx++] = pdesc->name;
 			}
-
-			grp = func->group_names;
-			while (*grp)
-				grp++;
-
-			*grp = pdesc->name;
-			mux++;
 		}
+
+		func->group_names = group_names;
 	}
 
 	/* Add all functions */
 	for (i = 0; i < kpc->nfuncs; i++) {
 		pinmux_generic_add_function(kpc->pctrl,
-					    function[i].name,
-					    function[i].group_names,
-					    function[i].num_group_names,
-					    function[i].data);
+					    functions[i].name,
+					    functions[i].group_names,
+					    functions[i].num_group_names,
+					    functions[i].data);
 	}
 
 	return 0;