add gpiolib support

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>

3 files changed, 137 insertions, 0 deletions

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
new file mode 100644
index 0000000000..a681973d2b
--- /dev/null
+++ b/drivers/gpio/Kconfig
@@ -0,0 +1,2 @@
+config GPIOLIB
+	bool
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
new file mode 100644
index 0000000000..25abbce345
--- /dev/null
+++ b/drivers/gpio/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_GPIOLIB) += gpio.o
diff --git a/drivers/gpio/gpio.c b/drivers/gpio/gpio.c
new file mode 100644
index 0000000000..6ad8d274e7
--- /dev/null
+++ b/drivers/gpio/gpio.c
@@ -0,0 +1,134 @@
+#include <common.h>
+#include <gpio.h>
+#include <errno.h>
+
+static LIST_HEAD(chip_list);
+
+#define ARCH_NR_GPIOS 256
+
+static struct gpio_chip *gpio_desc[ARCH_NR_GPIOS];
+
+static int gpio_is_valid(unsigned gpio)
+{
+	if (gpio < ARCH_NR_GPIOS)
+		return 1;
+	return 0;
+}
+
+void gpio_set_value(unsigned gpio, int value)
+{
+	struct gpio_chip *chip = gpio_desc[gpio];
+
+	if (!gpio_is_valid(gpio))
+		return;
+	if (!chip)
+		return;
+	if (!chip->ops->set)
+		return;
+	chip->ops->set(chip, gpio - chip->base, value);
+}
+EXPORT_SYMBOL(gpio_set_value);
+
+int gpio_get_value(unsigned gpio)
+{
+	struct gpio_chip *chip = gpio_desc[gpio];
+
+	if (!gpio_is_valid(gpio))
+		return -EINVAL;
+	if (!chip)
+		return -ENODEV;
+	if (!chip->ops->get)
+		return -ENOSYS;
+	return chip->ops->get(chip, gpio - chip->base);
+}
+EXPORT_SYMBOL(gpio_get_value);
+
+int gpio_direction_output(unsigned gpio, int value)
+{
+	struct gpio_chip *chip = gpio_desc[gpio];
+
+	if (!gpio_is_valid(gpio))
+		return -EINVAL;
+	if (!chip)
+		return -ENODEV;
+	if (!chip->ops->direction_output)
+		return -ENOSYS;
+	return chip->ops->direction_output(chip, gpio - chip->base, value);
+}
+EXPORT_SYMBOL(gpio_direction_output);
+
+int gpio_direction_input(unsigned gpio)
+{
+	struct gpio_chip *chip = gpio_desc[gpio];
+
+	if (!gpio_is_valid(gpio))
+		return -EINVAL;
+	if (!chip)
+		return -ENODEV;
+	if (!chip->ops->direction_input)
+		return -ENOSYS;
+	return chip->ops->direction_input(chip, gpio - chip->base);
+}
+EXPORT_SYMBOL(gpio_direction_input);
+
+static int gpiochip_find_base(int start, int ngpio)
+{
+	int i;
+	int spare = 0;
+	int base = -ENOSPC;
+
+	if (start < 0)
+		start = 0;
+
+	for (i = start; i < ARCH_NR_GPIOS; i++) {
+		struct gpio_chip *chip = gpio_desc[i];
+
+		if (!chip) {
+			spare++;
+			if (spare == ngpio) {
+				base = i + 1 - ngpio;
+				break;
+			}
+		} else {
+			spare = 0;
+			i += chip->ngpio - 1;
+		}
+	}
+
+	if (gpio_is_valid(base))
+		debug("%s: found new base at %d\n", __func__, base);
+	return base;
+}
+
+int gpiochip_add(struct gpio_chip *chip)
+{
+	int base, i;
+
+	base = gpiochip_find_base(chip->base, chip->ngpio);
+	if (base < 0)
+		return base;
+
+	if (chip->base >= 0 && chip->base != base)
+		return -EBUSY;
+
+	chip->base = base;
+
+	list_add_tail(&chip->list, &chip_list);
+
+	for (i = chip->base; i < chip->base + chip->ngpio; i++)
+		gpio_desc[i] = chip;
+
+	return 0;
+}
+
+int gpio_get_num(struct device_d *dev, int gpio)
+{
+	struct gpio_chip *chip;
+
+	list_for_each_entry(chip, &chip_list, list) {
+		if (chip->dev == dev)
+			return chip->base + gpio;
+	}
+
+	return -ENODEV;
+}