1 files changed, 143 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-bd71828.c b/drivers/gpio/gpio-bd71828.c
new file mode 100644
index 000000000..b2ccc320c
--- /dev/null
+++ b/drivers/gpio/gpio-bd71828.c
@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2018 ROHM Semiconductors
+
+#include <linux/gpio/driver.h>
+#include <linux/mfd/rohm-bd71828.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#define GPIO_OUT_REG(off) (BD71828_REG_GPIO_CTRL1 + (off))
+#define HALL_GPIO_OFFSET 3
+
+struct bd71828_gpio {
+	struct regmap *regmap;
+	struct device *dev;
+	struct gpio_chip gpio;
+};
+
+static void bd71828_gpio_set(struct gpio_chip *chip, unsigned int offset,
+			     int value)
+{
+	int ret;
+	struct bd71828_gpio *bdgpio = gpiochip_get_data(chip);
+	u8 val = (value) ? BD71828_GPIO_OUT_HI : BD71828_GPIO_OUT_LO;
+
+	/*
+	 * The HALL input pin can only be used as input. If this is the pin
+	 * we are dealing with - then we are done
+	 */
+	if (offset == HALL_GPIO_OFFSET)
+		return;
+
+	ret = regmap_update_bits(bdgpio->regmap, GPIO_OUT_REG(offset),
+				 BD71828_GPIO_OUT_MASK, val);
+	if (ret)
+		dev_err(bdgpio->dev, "Could not set gpio to %d\n", value);
+}
+
+static int bd71828_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+	int ret;
+	unsigned int val;
+	struct bd71828_gpio *bdgpio = gpiochip_get_data(chip);
+
+	if (offset == HALL_GPIO_OFFSET)
+		ret = regmap_read(bdgpio->regmap, BD71828_REG_IO_STAT,
+				  &val);
+	else
+		ret = regmap_read(bdgpio->regmap, GPIO_OUT_REG(offset),
+				  &val);
+	if (!ret)
+		ret = (val & BD71828_GPIO_OUT_MASK);
+
+	return ret;
+}
+
+static int bd71828_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
+				   unsigned long config)
+{
+	struct bd71828_gpio *bdgpio = gpiochip_get_data(chip);
+
+	if (offset == HALL_GPIO_OFFSET)
+		return -ENOTSUPP;
+
+	switch (pinconf_to_config_param(config)) {
+	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
+		return regmap_update_bits(bdgpio->regmap,
+					  GPIO_OUT_REG(offset),
+					  BD71828_GPIO_DRIVE_MASK,
+					  BD71828_GPIO_OPEN_DRAIN);
+	case PIN_CONFIG_DRIVE_PUSH_PULL:
+		return regmap_update_bits(bdgpio->regmap,
+					  GPIO_OUT_REG(offset),
+					  BD71828_GPIO_DRIVE_MASK,
+					  BD71828_GPIO_PUSH_PULL);
+	default:
+		break;
+	}
+	return -ENOTSUPP;
+}
+
+static int bd71828_get_direction(struct gpio_chip *chip, unsigned int offset)
+{
+	/*
+	 * Pin usage is selected by OTP data. We can't read it runtime. Hence
+	 * we trust that if the pin is not excluded by "gpio-reserved-ranges"
+	 * the OTP configuration is set to OUT. (Other pins but HALL input pin
+	 * on BD71828 can't really be used for general purpose input - input
+	 * states are used for specific cases like regulator control or
+	 * PMIC_ON_REQ.
+	 */
+	if (offset == HALL_GPIO_OFFSET)
+		return GPIO_LINE_DIRECTION_IN;
+
+	return GPIO_LINE_DIRECTION_OUT;
+}
+
+static int bd71828_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct bd71828_gpio *bdgpio;
+
+	bdgpio = devm_kzalloc(dev, sizeof(*bdgpio), GFP_KERNEL);
+	if (!bdgpio)
+		return -ENOMEM;
+
+	bdgpio->dev = dev;
+	bdgpio->gpio.parent = dev->parent;
+	bdgpio->gpio.label = "bd71828-gpio";
+	bdgpio->gpio.owner = THIS_MODULE;
+	bdgpio->gpio.get_direction = bd71828_get_direction;
+	bdgpio->gpio.set_config = bd71828_gpio_set_config;
+	bdgpio->gpio.can_sleep = true;
+	bdgpio->gpio.get = bd71828_gpio_get;
+	bdgpio->gpio.set = bd71828_gpio_set;
+	bdgpio->gpio.base = -1;
+
+	/*
+	 * See if we need some implementation to mark some PINs as
+	 * not controllable based on DT info or if core can handle
+	 * "gpio-reserved-ranges" and exclude them from control
+	 */
+	bdgpio->gpio.ngpio = 4;
+	bdgpio->regmap = dev_get_regmap(dev->parent, NULL);
+	if (!bdgpio->regmap)
+		return -ENODEV;
+
+	return devm_gpiochip_add_data(dev, &bdgpio->gpio, bdgpio);
+}
+
+static struct platform_driver bd71828_gpio = {
+	.driver = {
+		.name = "bd71828-gpio"
+	},
+	.probe = bd71828_probe,
+};
+
+module_platform_driver(bd71828_gpio);
+
+MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
+MODULE_DESCRIPTION("BD71828 voltage regulator driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:bd71828-gpio");