[PATCH RTF 1/2] gpiolib: of: Use local variables

Linus Walleij
2025-02-18T10:28:06Z

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

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
drivers/gpio/gpiolib-of.c | 39 +++++++++++++++++++++++----------------
1 file changed, 23 insertions(+), 16 deletions(-)

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 2e537ee979f3e2b6e8d5f86f3e121a66f2a8e083..86405218f4e2ddc951a1a9d168e886400652bf60 100644
--- 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;
}

--
2.48.1