6 files changed, 178 insertions, 6 deletions

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index b585f2ef6dd9..b8013cf90064 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1035,6 +1035,18 @@ config GPIO_BD70528
 	  This driver can also be built as a module. If so, the module
 	  will be called gpio-bd70528.
 
+config GPIO_BD71828
+	tristate "ROHM BD71828 GPIO support"
+	depends on MFD_ROHM_BD71828
+	help
+	  Support for GPIOs on ROHM BD71828 PMIC. There are three GPIOs
+	  available on the ROHM PMIC in total. The GPIOs are limited to
+	  outputs only and pins must be configured to GPIO outputs by
+	  OTP. Enable this only if you want to use these pins as outputs.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called gpio-bd71828.
+
 config GPIO_BD9571MWV
 	tristate "ROHM BD9571 GPIO support"
 	depends on MFD_BD9571MWV
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 76ff2a5feaba..0b571264ddbc 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -37,6 +37,7 @@ obj-$(CONFIG_GPIO_ATH79)		+= gpio-ath79.o
 obj-$(CONFIG_GPIO_BCM_KONA)		+= gpio-bcm-kona.o
 obj-$(CONFIG_GPIO_BCM_XGS_IPROC)	+= gpio-xgs-iproc.o
 obj-$(CONFIG_GPIO_BD70528)		+= gpio-bd70528.o
+obj-$(CONFIG_GPIO_BD71828)		+= gpio-bd71828.o
 obj-$(CONFIG_GPIO_BD9571MWV)		+= gpio-bd9571mwv.o
 obj-$(CONFIG_GPIO_BRCMSTB)		+= gpio-brcmstb.o
 obj-$(CONFIG_GPIO_BT8XX)		+= gpio-bt8xx.o
diff --git a/drivers/gpio/gpio-bd71828.c b/drivers/gpio/gpio-bd71828.c
new file mode 100644
index 000000000000..04aade9e0a4d
--- /dev/null
+++ b/drivers/gpio/gpio-bd71828.c
@@ -0,0 +1,159 @@
+// 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
+
+/*
+ * These defines can be removed when
+ * "gpio: Add definition for GPIO direction"
+ * (9208b1e77d6e8e9776f34f46ef4079ecac9c3c25 in GPIO tree) gets merged,
+ */
+#ifndef GPIO_LINE_DIRECTION_IN
+	#define GPIO_LINE_DIRECTION_IN 1
+	#define GPIO_LINE_DIRECTION_OUT 0
+#endif
+
+struct bd71828_gpio {
+	struct rohm_regmap_dev chip;
+	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->chip.regmap, GPIO_OUT_REG(offset),
+				 BD71828_GPIO_OUT_MASK, val);
+	if (ret)
+		dev_err(bdgpio->chip.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->chip.regmap, BD71828_REG_IO_STAT,
+				  &val);
+	else
+		ret = regmap_read(bdgpio->chip.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->chip.regmap,
+					  GPIO_OUT_REG(offset),
+					  BD71828_GPIO_DRIVE_MASK,
+					  BD71828_GPIO_OPEN_DRAIN);
+	case PIN_CONFIG_DRIVE_PUSH_PULL:
+		return regmap_update_bits(bdgpio->chip.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 bd71828_gpio *bdgpio;
+	struct rohm_regmap_dev *bd71828;
+
+	bd71828 = dev_get_drvdata(pdev->dev.parent);
+	if (!bd71828) {
+		dev_err(&pdev->dev, "No MFD driver data\n");
+		return -EINVAL;
+	}
+
+	bdgpio = devm_kzalloc(&pdev->dev, sizeof(*bdgpio),
+			      GFP_KERNEL);
+	if (!bdgpio)
+		return -ENOMEM;
+
+	bdgpio->chip.dev = &pdev->dev;
+	bdgpio->gpio.parent = pdev->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->gpio.of_node = pdev->dev.parent->of_node;
+	bdgpio->chip.regmap = bd71828->regmap;
+
+	return devm_gpiochip_add_data(&pdev->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");
diff --git a/drivers/gpio/gpiolib-devres.c b/drivers/gpio/gpiolib-devres.c
index 4421be09b960..72b6001c56ef 100644
--- a/drivers/gpio/gpiolib-devres.c
+++ b/drivers/gpio/gpiolib-devres.c
@@ -308,7 +308,7 @@ devm_gpiod_get_array_optional(struct device *dev, const char *con_id,
 	struct gpio_descs *descs;
 
 	descs = devm_gpiod_get_array(dev, con_id, flags);
-	if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
+	if (PTR_ERR(descs) == -ENOENT)
 		return NULL;
 
 	return descs;
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 1b3f217a35e2..c6d30f73df07 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -484,24 +484,24 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
 			break;
 	}
 
-	if (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT) {
+	if (PTR_ERR(desc) == -ENOENT) {
 		/* Special handling for SPI GPIOs if used */
 		desc = of_find_spi_gpio(dev, con_id, &of_flags);
 	}
 
-	if (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT) {
+	if (PTR_ERR(desc) == -ENOENT) {
 		/* This quirk looks up flags and all */
 		desc = of_find_spi_cs_gpio(dev, con_id, idx, flags);
 		if (!IS_ERR(desc))
 			return desc;
 	}
 
-	if (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT) {
+	if (PTR_ERR(desc) == -ENOENT) {
 		/* Special handling for regulator GPIOs if used */
 		desc = of_find_regulator_gpio(dev, con_id, &of_flags);
 	}
 
-	if (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
+	if (PTR_ERR(desc) == -ENOENT)
 		desc = of_find_arizona_gpio(dev, con_id, &of_flags);
 
 	if (IS_ERR(desc))
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 99ac27a72e28..753283486037 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -5039,7 +5039,7 @@ struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
 	struct gpio_descs *descs;
 
 	descs = gpiod_get_array(dev, con_id, flags);
-	if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
+	if (PTR_ERR(descs) == -ENOENT)
 		return NULL;
 
 	return descs;