gpiolib: of: Use local variables

Instead of modifying the contents of the array of values read
in from a phandle, use local variables to store the values.
This makes the code easier to read and the array immutable.

Reviewed-by: Alex Elder <elder@riscstar.com>
Tested-by: Yixun Lan <dlan@gentoo.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20250225-gpio-ranges-fourcell-v3-1-860382ba4713@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 2e537ee979f3e2b6e8d5f86f3e121a66f2a8e083..86405218f4e2ddc951a1a9d168e886400652bf60 100644 (file)
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -1057,6 +1057,9 @@ static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
        const char *name;
        static const char group_names_propname[] = "gpio-ranges-group-names";
        bool has_group_names;
+       int offset; /* Offset of the first GPIO line on the chip */
+       int pin; /* Pin base number in the range */
+       int count; /* Number of pins/GPIO lines to map */
 
        np = dev_of_node(&chip->gpiodev->dev);
        if (!np)
@@ -1075,13 +1078,17 @@ static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
                if (!pctldev)
                        return -EPROBE_DEFER;
 
+               offset = pinspec.args[0];
+               pin = pinspec.args[1];
+               count = pinspec.args[2];
+
                /* Ignore ranges outside of this GPIO chip */
-               if (pinspec.args[0] >= (chip->offset + chip->ngpio))
+               if (offset >= (chip->offset + chip->ngpio))
                        continue;
-               if (pinspec.args[0] + pinspec.args[2] <= chip->offset)
+               if (offset + count <= chip->offset)
                        continue;
 
-               if (pinspec.args[2]) {
+               if (count) {
                        /* npins != 0: linear range */
                        if (has_group_names) {
                                of_property_read_string_index(np,
@@ -1095,27 +1102,27 @@ static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
                        }
 
                        /* Trim the range to fit this GPIO chip */
-                       if (chip->offset > pinspec.args[0]) {
-                               trim = chip->offset - pinspec.args[0];
-                               pinspec.args[2] -= trim;
-                               pinspec.args[1] += trim;
-                               pinspec.args[0] = 0;
+                       if (chip->offset > offset) {
+                               trim = chip->offset - offset;
+                               count -= trim;
+                               pin += trim;
+                               offset = 0;
                        } else {
-                               pinspec.args[0] -= chip->offset;
+                               offset -= chip->offset;
                        }
-                       if ((pinspec.args[0] + pinspec.args[2]) > chip->ngpio)
-                               pinspec.args[2] = chip->ngpio - pinspec.args[0];
+                       if ((offset + count) > chip->ngpio)
+                               count = chip->ngpio - offset;
 
                        ret = gpiochip_add_pin_range(chip,
                                        pinctrl_dev_get_devname(pctldev),
-                                       pinspec.args[0],
-                                       pinspec.args[1],
-                                       pinspec.args[2]);
+                                       offset,
+                                       pin,
+                                       count);
                        if (ret)
                                return ret;
                } else {
                        /* npins == 0: special range */
-                       if (pinspec.args[1]) {
+                       if (pin) {
                                pr_err("%pOF: Illegal gpio-range format.\n",
                                        np);
                                break;
@@ -1140,7 +1147,7 @@ static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
                        }
 
                        ret = gpiochip_add_pingroup_range(chip, pctldev,
-                                               pinspec.args[0], name);
+                                               offset, name);
                        if (ret)
                                return ret;
                }