pinctrl/gpio: non-linear GPIO ranges accesible from gpiolib
This patch adds the infrastructure required to register non-linear gpio
ranges through gpiolib and the standard GPIO device tree bindings.
Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 0dfaf20..e787609 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -190,10 +190,15 @@
struct of_phandle_args pinspec;
struct pinctrl_dev *pctldev;
int index = 0, ret;
+ const char *name;
+ static const char group_names_propname[] = "gpio-ranges-group-names";
+ struct property *group_names;
if (!np)
return;
+ group_names = of_find_property(np, group_names_propname, NULL);
+
for (;; index++) {
ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
index, &pinspec);
@@ -204,14 +209,56 @@
if (!pctldev)
break;
- ret = gpiochip_add_pin_range(chip,
- pinctrl_dev_get_devname(pctldev),
- pinspec.args[0],
- pinspec.args[1],
- pinspec.args[2]);
+ if (pinspec.args[2]) {
+ if (group_names) {
+ ret = of_property_read_string_index(np,
+ group_names_propname,
+ index, &name);
+ if (strlen(name)) {
+ pr_err("%s: Group name of numeric GPIO ranges must be the empty string.\n",
+ np->full_name);
+ break;
+ }
+ }
+ /* npins != 0: linear range */
+ ret = gpiochip_add_pin_range(chip,
+ pinctrl_dev_get_devname(pctldev),
+ pinspec.args[0],
+ pinspec.args[1],
+ pinspec.args[2]);
+ if (ret)
+ break;
+ } else {
+ /* npins == 0: special range */
+ if (pinspec.args[1]) {
+ pr_err("%s: Illegal gpio-range format.\n",
+ np->full_name);
+ break;
+ }
- if (ret)
- break;
+ if (!group_names) {
+ pr_err("%s: GPIO group range requested but no %s property.\n",
+ np->full_name, group_names_propname);
+ break;
+ }
+
+ ret = of_property_read_string_index(np,
+ group_names_propname,
+ index, &name);
+ if (ret)
+ break;
+
+ if (!strlen(name)) {
+ pr_err("%s: Group name of GPIO group range cannot be the empty string.\n",
+ np->full_name);
+ break;
+ }
+
+ ret = gpiochip_add_pingroup_range(chip, pctldev,
+ pinspec.args[0], name);
+ if (ret)
+ break;
+ }
}
}
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 86ef346..b83b7e4 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1320,6 +1320,53 @@
#ifdef CONFIG_PINCTRL
/**
+ * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
+ * @chip: the gpiochip to add the range for
+ * @pinctrl: the dev_name() of the pin controller to map to
+ * @gpio_offset: the start offset in the current gpio_chip number space
+ * @pin_group: name of the pin group inside the pin controller
+ */
+int gpiochip_add_pingroup_range(struct gpio_chip *chip,
+ struct pinctrl_dev *pctldev,
+ unsigned int gpio_offset, const char *pin_group)
+{
+ struct gpio_pin_range *pin_range;
+ int ret;
+
+ pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
+ if (!pin_range) {
+ pr_err("%s: GPIO chip: failed to allocate pin ranges\n",
+ chip->label);
+ return -ENOMEM;
+ }
+
+ /* Use local offset as range ID */
+ pin_range->range.id = gpio_offset;
+ pin_range->range.gc = chip;
+ pin_range->range.name = chip->label;
+ pin_range->range.base = chip->base + gpio_offset;
+ pin_range->pctldev = pctldev;
+
+ ret = pinctrl_get_group_pins(pctldev, pin_group,
+ &pin_range->range.pins,
+ &pin_range->range.npins);
+ if (ret < 0)
+ return ret;
+
+ pinctrl_add_gpio_range(pctldev, &pin_range->range);
+
+ pr_debug("GPIO chip %s: created GPIO range %d->%d ==> %s PINGRP %s\n",
+ chip->label, gpio_offset,
+ gpio_offset + pin_range->range.npins - 1,
+ pinctrl_dev_get_devname(pctldev), pin_group);
+
+ list_add_tail(&pin_range->node, &chip->pin_ranges);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
+
+/**
* gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
* @chip: the gpiochip to add the range for
* @pinctrl_name: the dev_name() of the pin controller to map to