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path: root/drivers/gpio/gpiolib-of.c
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Diffstat (limited to 'drivers/gpio/gpiolib-of.c')
-rw-r--r--drivers/gpio/gpiolib-of.c128
1 files changed, 104 insertions, 24 deletions
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 2e537ee979f3..6e0eb67dcbf0 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -929,7 +929,7 @@ struct notifier_block gpio_of_notifier = {
#endif /* CONFIG_OF_DYNAMIC */
/**
- * of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags
+ * of_gpio_twocell_xlate - translate twocell gpiospec to the GPIO number and flags
* @gc: pointer to the gpio_chip structure
* @gpiospec: GPIO specifier as found in the device tree
* @flags: a flags pointer to fill in
@@ -941,9 +941,9 @@ struct notifier_block gpio_of_notifier = {
* Returns:
* GPIO number (>= 0) on success, negative errno on failure.
*/
-static int of_gpio_simple_xlate(struct gpio_chip *gc,
- const struct of_phandle_args *gpiospec,
- u32 *flags)
+static int of_gpio_twocell_xlate(struct gpio_chip *gc,
+ const struct of_phandle_args *gpiospec,
+ u32 *flags)
{
/*
* We're discouraging gpio_cells < 2, since that way you'll have to
@@ -951,7 +951,7 @@ static int of_gpio_simple_xlate(struct gpio_chip *gc,
* number and the flags from a single gpio cell -- this is possible,
* but not recommended).
*/
- if (gc->of_gpio_n_cells < 2) {
+ if (gc->of_gpio_n_cells != 2) {
WARN_ON(1);
return -EINVAL;
}
@@ -968,6 +968,49 @@ static int of_gpio_simple_xlate(struct gpio_chip *gc,
return gpiospec->args[0];
}
+/**
+ * of_gpio_threecell_xlate - translate threecell gpiospec to the GPIO number and flags
+ * @gc: pointer to the gpio_chip structure
+ * @gpiospec: GPIO specifier as found in the device tree
+ * @flags: a flags pointer to fill in
+ *
+ * This is simple translation function, suitable for the most 1:n mapped
+ * GPIO chips, i.e. several GPIO chip instances from one device tree node.
+ * In this case the following binding is implied:
+ *
+ * foo-gpios = <&gpio instance offset flags>;
+ *
+ * Returns:
+ * GPIO number (>= 0) on success, negative errno on failure.
+ */
+static int of_gpio_threecell_xlate(struct gpio_chip *gc,
+ const struct of_phandle_args *gpiospec,
+ u32 *flags)
+{
+ if (gc->of_gpio_n_cells != 3) {
+ WARN_ON(1);
+ return -EINVAL;
+ }
+
+ if (WARN_ON(gpiospec->args_count != 3))
+ return -EINVAL;
+
+ /*
+ * Check chip instance number, the driver responds with true if
+ * this is the chip we are looking for.
+ */
+ if (!gc->of_node_instance_match(gc, gpiospec->args[0]))
+ return -EINVAL;
+
+ if (gpiospec->args[1] >= gc->ngpio)
+ return -EINVAL;
+
+ if (flags)
+ *flags = gpiospec->args[2];
+
+ return gpiospec->args[1];
+}
+
#if IS_ENABLED(CONFIG_OF_GPIO_MM_GPIOCHIP)
#include <linux/gpio/legacy-of-mm-gpiochip.h>
/**
@@ -1057,6 +1100,9 @@ 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)
@@ -1065,7 +1111,15 @@ static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
has_group_names = of_property_present(np, group_names_propname);
for (;; index++) {
- ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
+ /*
+ * Ordinary phandles contain 2-3 cells:
+ * gpios = <&gpio [instance] offset flags>;
+ * Ranges always contain one more cell:
+ * gpio-ranges <&pinctrl [gpio_instance] gpio_offet pin_offet count>;
+ * This is why we parse chip->of_gpio_n_cells + 1 cells
+ */
+ ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges",
+ chip->of_gpio_n_cells + 1,
index, &pinspec);
if (ret)
break;
@@ -1075,13 +1129,33 @@ static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
if (!pctldev)
return -EPROBE_DEFER;
+ if (chip->of_gpio_n_cells == 3) {
+ /* First cell is the gpiochip instance number */
+ offset = pinspec.args[1];
+ pin = pinspec.args[2];
+ count = pinspec.args[3];
+ } else {
+ offset = pinspec.args[0];
+ pin = pinspec.args[1];
+ count = pinspec.args[2];
+ }
+
+ /*
+ * With multiple GPIO chips per node, check that this chip is the
+ * right instance.
+ */
+ if (chip->of_node_instance_match &&
+ (chip->of_gpio_n_cells == 3) &&
+ !chip->of_node_instance_match(chip, pinspec.args[0]))
+ continue;
+
/* 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 +1169,27 @@ 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 +1214,7 @@ 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;
}
@@ -1163,8 +1237,14 @@ int of_gpiochip_add(struct gpio_chip *chip)
return 0;
if (!chip->of_xlate) {
- chip->of_gpio_n_cells = 2;
- chip->of_xlate = of_gpio_simple_xlate;
+ if (chip->of_gpio_n_cells == 3) {
+ if (!chip->of_node_instance_match)
+ return -EINVAL;
+ chip->of_xlate = of_gpio_threecell_xlate;
+ } else {
+ chip->of_gpio_n_cells = 2;
+ chip->of_xlate = of_gpio_twocell_xlate;
+ }
}
if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS)
generated by cgit v1.2.3 (git 2.46.0) at 2025-08-27 09:09:53 +0000