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>

1 files changed, 47 insertions, 0 deletions

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 @@ EXPORT_SYMBOL_GPL(gpiochip_find);
 #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