[PATCH 0/5] RTL8231 GPIO expander support

@@ -1076,6 +1076,15 @@ config MFD_RDC321X
 	  southbridge which provides access to GPIOs and Watchdog using the
 	  southbridge PCI device configuration space.
 
+config MFD_RTL8231
+	tristate "Realtek RTL8231 GPIO and LED expander"
+	select MFD_CORE
+	select REGMAP
+	help
+	  Support for the Realtek RTL8231 GPIO and LED expander.
+	  Provides up to 37 GPIOs, 88 LEDs, and one PWM output.
+	  When built as a module, this module will be named rtl8231_expander.
+
 config MFD_RT5033
 	tristate "Richtek RT5033 Power Management IC"
 	depends on I2C

@@ -234,6 +234,7 @@ obj-$(CONFIG_MFD_MENF21BMC)	+= menf21bmc.o
 obj-$(CONFIG_MFD_HI6421_PMIC)	+= hi6421-pmic-core.o
 obj-$(CONFIG_MFD_HI655X_PMIC)   += hi655x-pmic.o
 obj-$(CONFIG_MFD_DLN2)		+= dln2.o
+obj-$(CONFIG_MFD_RTL8231)	+= rtl8231.o
 obj-$(CONFIG_MFD_RT5033)	+= rt5033.o
 obj-$(CONFIG_MFD_SKY81452)	+= sky81452.o
 

@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/rtl8231.h>
+#include <linux/mdio.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+static const struct reg_field RTL8231_FIELD_LED_START = REG_FIELD(RTL8231_REG_FUNC0, 1, 1);
+static const struct reg_field RTL8231_FIELD_READY_CODE = REG_FIELD(RTL8231_REG_FUNC1, 4, 9);
+static const struct reg_field RTL8231_FIELD_SOFT_RESET = REG_FIELD(RTL8231_REG_PIN_HI_CFG, 15, 15);
+
+static const struct mfd_cell rtl8231_cells[] = {
+	{
+		.name = "rtl8231-pinctrl",
+		.of_compatible = "realtek,rtl8231-pinctrl",
+	},
+	{
+		.name = "rtl8231-leds",
+		.of_compatible = "realtek,rtl8231-leds",
+	},
+};
+
+static int rtl8231_init(struct device *dev, struct regmap *map)
+{
+	struct regmap_field *field_ready_code;
+	struct regmap_field *field_soft_reset;
+	unsigned int v;
+	int err = 0;
+
+	field_ready_code = regmap_field_alloc(map, RTL8231_FIELD_READY_CODE);
+	if (IS_ERR(field_ready_code))
+		return PTR_ERR(field_ready_code);
+
+	field_soft_reset = regmap_field_alloc(map, RTL8231_FIELD_SOFT_RESET);
+	if (IS_ERR(field_soft_reset)) {
+		err = PTR_ERR(field_soft_reset);
+		goto init_out;
+	}
+
+	err = regmap_field_read(field_ready_code, &v);
+
+	if (err) {
+		dev_err(dev, "failed to read READY_CODE\n");
+		goto init_out;
+	} else if (v != RTL8231_FUNC1_READY_CODE_VALUE) {
+		dev_err(dev, "RTL8231 not present or ready 0x%x != 0x%x\n",
+			v, RTL8231_FUNC1_READY_CODE_VALUE);
+		err = -ENODEV;
+		goto init_out;
+	}
+
+	// TODO Implement reset-gpios
+	regmap_field_write(field_soft_reset, 1);
+	usleep_range(1000, 10000);
+
+	/* Do not write LED_START before configuring pins */
+	/* Select GPIO functionality for all pins and set to input */
+	regmap_write(map, RTL8231_REG_PIN_MODE0, 0xffff);
+	regmap_write(map, RTL8231_REG_GPIO_DIR0, 0xffff);
+	regmap_write(map, RTL8231_REG_PIN_MODE1, 0xffff);
+	regmap_write(map, RTL8231_REG_GPIO_DIR1, 0xffff);
+	regmap_write(map, RTL8231_REG_PIN_HI_CFG, GENMASK(4, 0) | GENMASK(9, 5));
+
+init_out:
+	regmap_field_free(field_ready_code);
+	regmap_field_free(field_soft_reset);
+	return err;
+}
+
+static int rtl8231_mdio_reg_read(void *ctx, unsigned int reg, unsigned int *val)
+{
+	struct mdio_device *mdiodev = ctx;
+	int ret;
+
+	ret = mdiobus_read(mdiodev->bus, mdiodev->addr, reg);
+	if (ret < 0)
+		return ret;
+
+	*val = ret & 0xffff;
+	return 0;
+}
+
+static int rtl8231_mdio_reg_write(void *ctx, unsigned int reg, unsigned int val)
+{
+	struct mdio_device *mdiodev = ctx;
+
+	return mdiobus_write(mdiodev->bus, mdiodev->addr, reg, val);
+}
+
+static const struct regmap_config rtl8231_regmap_config = {
+	.val_bits = 16,
+	.reg_bits = 5,
+	.max_register = RTL8231_REG_COUNT - 1,
+	.use_single_read = true,
+	.use_single_write = true,
+	.reg_format_endian = REGMAP_ENDIAN_BIG,
+	.val_format_endian = REGMAP_ENDIAN_BIG,
+	.reg_read = rtl8231_mdio_reg_read,
+	.reg_write = rtl8231_mdio_reg_write,
+};
+
+static int rtl8231_mdio_probe(struct mdio_device *mdiodev)
+{
+	struct device *dev = &mdiodev->dev;
+	struct regmap_field *led_start;
+	struct regmap *map;
+	int err;
+
+	map = devm_regmap_init(dev, NULL, mdiodev, &rtl8231_regmap_config);
+
+	if (IS_ERR(map)) {
+		dev_err(dev, "failed to init regmap\n");
+		return PTR_ERR(map);
+	}
+
+	led_start = devm_regmap_field_alloc(dev, map, RTL8231_FIELD_LED_START);
+	if (IS_ERR(led_start))
+		return PTR_ERR(led_start);
+
+	dev_set_drvdata(dev, led_start);
+
+	err = rtl8231_init(dev, map);
+	if (err)
+		return err;
+
+	/* LED_START enables power to output pins, and starts the LED engine */
+	regmap_field_write(led_start, 1);
+
+	return devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, rtl8231_cells,
+		ARRAY_SIZE(rtl8231_cells), NULL, 0, NULL);
+}
+
+static void rtl8231_mdio_remove(struct mdio_device *mdiodev)
+{
+	struct regmap_field *led_start;
+
+	led_start = dev_get_drvdata(&mdiodev->dev);
+	regmap_field_write(led_start, 0);
+}
+
+static const struct of_device_id rtl8231_of_match[] = {
+	{ .compatible = "realtek,rtl8231" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, rtl8231_of_match);
+
+static struct mdio_driver rtl8231_mdio_driver = {
+	.mdiodrv.driver = {
+		.name = "rtl8231-expander",
+		.of_match_table	= rtl8231_of_match,
+	},
+	.probe = rtl8231_mdio_probe,
+	.remove = rtl8231_mdio_remove,
+};
+mdio_module_driver(rtl8231_mdio_driver);
+
+MODULE_AUTHOR("Sander Vanheule <sander@svanheule.net>");
+MODULE_DESCRIPTION("Realtek RTL8231 GPIO and LED expander");
+MODULE_LICENSE("GPL v2");

@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Register definitions the RTL8231 GPIO and LED expander chip
+ */
+
+#ifndef __LINUX_MFD_RTL8231_H
+#define __LINUX_MFD_RTL8231_H
+
+/* Chip control */
+#define RTL8231_REG_FUNC0		0x00
+#define RTL8231_FUNC0_SCAN_MODE		BIT(0)
+#define RTL8231_FUNC0_SCAN_SINGLE	0
+#define RTL8231_FUNC0_SCAN_BICOLOR	BIT(0)
+
+#define RTL8231_REG_FUNC1		0x01
+#define RTL8231_FUNC1_READY_CODE_VALUE	0x37
+
+/* Pin control */
+#define RTL8231_REG_PIN_MODE0		0x02
+#define RTL8231_REG_PIN_MODE1		0x03
+
+#define RTL8231_PIN_MODE_LED		0
+#define RTL8231_PIN_MODE_GPIO		1
+
+/* Pin high config: pin and GPIO control for pins 32-26 */
+#define RTL8231_REG_PIN_HI_CFG		0x04
+
+/* GPIO control registers */
+#define RTL8231_REG_GPIO_DIR0		0x05
+#define RTL8231_REG_GPIO_DIR1		0x06
+#define RTL8231_REG_GPIO_INVERT0	0x07
+#define RTL8231_REG_GPIO_INVERT1	0x08
+
+#define RTL8231_GPIO_DIR_IN		1
+#define RTL8231_GPIO_DIR_OUT		0
+
+/* GPIO data registers */
+#define RTL8231_REG_GPIO_DATA0		0x1c
+#define RTL8231_REG_GPIO_DATA1		0x1d
+#define RTL8231_REG_GPIO_DATA2		0x1e
+
+/* LED control base registers */
+#define RTL8231_REG_LED0_BASE		0x09
+#define RTL8231_REG_LED1_BASE		0x10
+#define RTL8231_REG_LED2_BASE		0x17
+
+#define RTL8231_REG_COUNT		0x1f
+
+#endif /* __LINUX_MFD_RTL8231_H */

@@ -593,6 +593,16 @@ config LEDS_REGULATOR
 	help
 	  This option enables support for regulator driven LEDs.
 
+config LEDS_RTL8231
+	tristate "RTL8231 LED matrix support"
+	depends on LEDS_CLASS
+	depends on MFD_RTL8231
+	default MFD_RTL8231
+	help
+	  This options enables support for using the LED scanning matrix output
+	  of the RTL8231 GPIO and LED expander chip.
+	  When built as a module, this module will be named rtl8231_leds.
+
 config LEDS_BD2802
 	tristate "LED driver for BD2802 RGB LED"
 	depends on LEDS_CLASS

@@ -80,6 +80,7 @@ obj-$(CONFIG_LEDS_PM8058)		+= leds-pm8058.o
 obj-$(CONFIG_LEDS_POWERNV)		+= leds-powernv.o
 obj-$(CONFIG_LEDS_PWM)			+= leds-pwm.o
 obj-$(CONFIG_LEDS_REGULATOR)		+= leds-regulator.o
+obj-$(CONFIG_LEDS_RTL8231)		+= leds-rtl8231.o
 obj-$(CONFIG_LEDS_S3C24XX)		+= leds-s3c24xx.o
 obj-$(CONFIG_LEDS_SC27XX_BLTC)		+= leds-sc27xx-bltc.o
 obj-$(CONFIG_LEDS_SGM3140)		+= leds-sgm3140.o

@@ -0,0 +1,281 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/device.h>
+#include <linux/leds.h>
+#include <linux/mfd/rtl8231.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/property.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+struct led_toggle_rate {
+	u16 interval; /* Toggle interval in ms */
+	u8 mode; /* Register value */
+};
+
+struct led_modes {
+	/* Array of toggle rates, sorted by interval */
+	const struct led_toggle_rate *toggle_rates;
+	unsigned int num_toggle_rates;
+	u8 off;
+	u8 on;
+};
+
+struct rtl8231_led {
+	struct led_classdev led;
+	const struct led_modes *modes;
+	struct regmap_field *reg_field;
+};
+#define to_rtl8231_led(_cdev) container_of(_cdev, struct rtl8231_led, led)
+
+#define RTL8231_NUM_LEDS	3
+#define RTL8231_LED_PER_REG	5
+#define RTL8231_BITS_PER_LED	3
+
+static const unsigned int rtl8231_led_port_count_single[RTL8231_NUM_LEDS] = {32, 32, 24};
+static const unsigned int rtl8231_led_port_count_bicolor[RTL8231_NUM_LEDS] = {24, 24, 24};
+
+static const unsigned int rtl8231_led_base[RTL8231_NUM_LEDS] = {
+	RTL8231_REG_LED0_BASE,
+	RTL8231_REG_LED1_BASE,
+	RTL8231_REG_LED2_BASE,
+};
+
+static const struct led_toggle_rate rtl8231_toggle_rates[] = {
+	{  40, 1},
+	{  80, 2},
+	{ 160, 3},
+	{ 320, 4},
+	{ 640, 5},
+	{1280, 6},
+};
+
+static const struct led_modes rtl8231_led_modes = {
+	.off = 0,
+	.on = 7,
+	.num_toggle_rates = ARRAY_SIZE(rtl8231_toggle_rates),
+	.toggle_rates = rtl8231_toggle_rates,
+};
+
+static void rtl8231_led_brightness_set(struct led_classdev *led_cdev,
+	enum led_brightness brightness)
+{
+	struct rtl8231_led *pled = to_rtl8231_led(led_cdev);
+
+	if (brightness)
+		regmap_field_write(pled->reg_field, pled->modes->on);
+	else
+		regmap_field_write(pled->reg_field, pled->modes->off);
+}
+
+static enum led_brightness rtl8231_led_brightness_get(struct led_classdev *led_cdev)
+{
+	struct rtl8231_led *pled = to_rtl8231_led(led_cdev);
+	u32 current_mode = pled->modes->off;
+
+	regmap_field_read(pled->reg_field, &current_mode);
+
+	if (current_mode == pled->modes->off)
+		return LED_OFF;
+	else
+		return LED_ON;
+}
+
+static unsigned int rtl8231_led_current_interval(struct rtl8231_led *pled)
+{
+	unsigned int mode;
+	unsigned int i = 0;
+
+	if (regmap_field_read(pled->reg_field, &mode))
+		return 0;
+
+	while (i < pled->modes->num_toggle_rates && mode != pled->modes->toggle_rates[i].mode)
+		i++;
+
+	if (i < pled->modes->num_toggle_rates)
+		return pled->modes->toggle_rates[i].interval;
+	else
+		return 0;
+}
+
+static int rtl8231_led_blink_set(struct led_classdev *led_cdev, unsigned long *delay_on,
+	unsigned long *delay_off)
+{
+	struct rtl8231_led *pled = to_rtl8231_led(led_cdev);
+	const struct led_modes *modes = pled->modes;
+	unsigned int interval;
+	unsigned int i = 0;
+	int err;
+
+	if (*delay_on == 0 && *delay_off == 0) {
+		/* Choose 500ms as default interval */
+		interval = 500;
+	} else {
+		/*
+		 * If the current mode is blinking, choose the delay that (likely) changed.
+		 * Otherwise, choose the interval that would have the same total delay.
+		 */
+		interval = rtl8231_led_current_interval(pled);
+
+		if (interval > 0 && interval == *delay_off)
+			interval = *delay_on;
+		else if (interval > 0 && interval == *delay_on)
+			interval = *delay_off;
+		else
+			interval = (*delay_on + *delay_off) / 2;
+	}
+
+	/* Find clamped toggle interval */
+	while (i < (modes->num_toggle_rates - 1) && interval > modes->toggle_rates[i].interval)
+		i++;
+
+	interval = modes->toggle_rates[i].interval;
+
+	err = regmap_field_write(pled->reg_field, modes->toggle_rates[i].mode);
+	if (err)
+		return err;
+
+	*delay_on = interval;
+	*delay_off = interval;
+
+	return 0;
+}
+
+static int rtl8231_led_read_address(struct device_node *np, unsigned int *addr_port,
+	unsigned int *addr_led)
+{
+	const __be32 *addr;
+
+	if (of_n_addr_cells(np) != 2 || of_n_size_cells(np) != 0)
+		return -ENODEV;
+
+	addr = of_get_address(np, 0, NULL, NULL);
+	if (!addr)
+		return -ENODEV;
+
+	*addr_port = of_read_number(addr, 1);
+	*addr_led = of_read_number(addr + 1, 1);
+
+	return 0;
+}
+
+static struct reg_field rtl8231_led_get_field(unsigned int port_index, unsigned int led_index)
+{
+	unsigned int offset, shift;
+	struct reg_field field;
+
+	offset = port_index / RTL8231_LED_PER_REG;
+	shift = (port_index % RTL8231_LED_PER_REG) * RTL8231_BITS_PER_LED;
+
+	field.reg = rtl8231_led_base[led_index] + offset;
+	field.lsb = shift;
+	field.msb = shift + RTL8231_BITS_PER_LED - 1;
+
+	return field;
+}
+
+static int rtl8231_led_probe_single(struct device *dev, struct regmap *map,
+	const unsigned int *port_count, struct device_node *np)
+{
+	struct rtl8231_led *pled;
+	unsigned int port_index;
+	unsigned int led_index;
+	struct reg_field field;
+	struct led_init_data init_data = {};
+	int err;
+
+	pled = devm_kzalloc(dev, sizeof(*pled), GFP_KERNEL);
+	if (IS_ERR(pled))
+		return PTR_ERR(pled);
+
+	err = rtl8231_led_read_address(np, &port_index, &led_index);
+
+	if (err) {
+		dev_err(dev, "LED address invalid\n");
+		return err;
+	} else if (led_index >= RTL8231_NUM_LEDS || port_index >= port_count[led_index]) {
+		dev_err(dev, "LED address (%d.%d) invalid\n", port_index, led_index);
+		return -ENODEV;
+	}
+
+	field = rtl8231_led_get_field(port_index, led_index);
+	pled->reg_field = devm_regmap_field_alloc(dev, map, field);
+	if (IS_ERR(pled->reg_field))
+		return PTR_ERR(pled->reg_field);
+
+	pled->modes = &rtl8231_led_modes;
+
+	pled->led.max_brightness = 1;
+	pled->led.brightness_get = rtl8231_led_brightness_get;
+	pled->led.brightness_set = rtl8231_led_brightness_set;
+	pled->led.blink_set = rtl8231_led_blink_set;
+
+	init_data.fwnode = of_fwnode_handle(np);
+
+	return devm_led_classdev_register_ext(dev, &pled->led, &init_data);
+}
+
+static int rtl8231_led_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	const unsigned int *port_count;
+	struct device_node *child;
+	struct regmap *map;
+	int err;
+
+	map = dev_get_regmap(dev->parent, NULL);
+	if (IS_ERR_OR_NULL(map)) {
+		dev_err(dev, "failed to retrieve regmap\n");
+		if (!map)
+			return -ENODEV;
+		else
+			return PTR_ERR(map);
+	}
+
+	if (!device_property_match_string(dev, "realtek,led-scan-mode", "single-color")) {
+		port_count = rtl8231_led_port_count_single;
+		regmap_update_bits(map, RTL8231_REG_FUNC0,
+			RTL8231_FUNC0_SCAN_MODE, RTL8231_FUNC0_SCAN_SINGLE);
+	} else if (!device_property_match_string(dev, "realtek,led-scan-mode", "bi-color")) {
+		port_count = rtl8231_led_port_count_bicolor;
+		regmap_update_bits(map, RTL8231_REG_FUNC0,
+			RTL8231_FUNC0_SCAN_MODE, RTL8231_FUNC0_SCAN_BICOLOR);
+	} else {
+		dev_err(dev, "scan mode missing or invalid\n");
+		return -EINVAL;
+	}
+
+	for_each_child_of_node(dev->of_node, child) {
+		if (of_node_name_prefix(child, "led")) {
+			err = rtl8231_led_probe_single(dev, map, port_count, child);
+			if (err)
+				dev_warn(dev, "failed to register %pOF\n", child);
+			continue;
+		}
+
+		dev_dbg(dev, "skipping unsupported node %pOF\n", child);
+	}
+
+	return 0;
+}
+
+static const struct of_device_id of_rtl8231_led_match[] = {
+	{ .compatible = "realtek,rtl8231-leds" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, of_rtl8231_led_match);
+
+static struct platform_driver rtl8231_led_driver = {
+	.driver = {
+		.name = "rtl8231-leds",
+		.of_match_table = of_rtl8231_led_match,
+	},
+	.probe = rtl8231_led_probe,
+};
+module_platform_driver(rtl8231_led_driver);
+
+MODULE_AUTHOR("Sander Vanheule <sander@svanheule.net>");
+MODULE_DESCRIPTION("Realtek RTL8231 LED support");
+MODULE_LICENSE("GPL v2");

@@ -221,6 +221,16 @@ config PINCTRL_ROCKCHIP
 	help
           This support pinctrl and gpio driver for Rockchip SoCs.
 
+config PINCTRL_RTL8231
+	tristate "Realtek RTL8231 GPIO expander's pin controller"
+	depends on MFD_RTL8231
+	default MFD_RTL8231
+	select GENERIC_PINCONF
+	select PINMUX
+	help
+	  Support for RTL8231 expander's GPIOs and pin controller.
+	  When built as a module, the module will be called rtl8231_pinctrl.
+
 config PINCTRL_SINGLE
 	tristate "One-register-per-pin type device tree based pinctrl driver"
 	depends on OF

@@ -30,6 +30,7 @@ obj-$(CONFIG_PINCTRL_PALMAS)	+= pinctrl-palmas.o
 obj-$(CONFIG_PINCTRL_PIC32)	+= pinctrl-pic32.o
 obj-$(CONFIG_PINCTRL_PISTACHIO)	+= pinctrl-pistachio.o
 obj-$(CONFIG_PINCTRL_ROCKCHIP)	+= pinctrl-rockchip.o
+obj-$(CONFIG_PINCTRL_RTL8231)	+= pinctrl-rtl8231.o
 obj-$(CONFIG_PINCTRL_SINGLE)	+= pinctrl-single.o
 obj-$(CONFIG_PINCTRL_SX150X)	+= pinctrl-sx150x.o
 obj-$(CONFIG_ARCH_TEGRA)	+= tegra/

@@ -0,0 +1,497 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/bitops.h>
+#include <linux/gpio/driver.h>
+#include <linux/mfd/rtl8231.h>
+#include <linux/module.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#define RTL8231_NUM_GPIOS	37
+
+enum rtl8231_gpio_regfield {
+	RTL8231_FIELD_GPIO_DIR0,
+	RTL8231_FIELD_GPIO_DIR1,
+	RTL8231_FIELD_GPIO_DIR2,
+	RTL8231_FIELD_GPIO_DATA0,
+	RTL8231_FIELD_GPIO_DATA1,
+	RTL8231_FIELD_GPIO_DATA2,
+	RTL8231_FIELD_GPIO_MAX
+};
+
+static struct reg_field rtl8231_gpio_fields[RTL8231_FIELD_GPIO_MAX] = {
+	[RTL8231_FIELD_GPIO_DIR0] = REG_FIELD(RTL8231_REG_GPIO_DIR0, 0, 15),
+	[RTL8231_FIELD_GPIO_DIR1] = REG_FIELD(RTL8231_REG_GPIO_DIR1, 0, 15),
+	[RTL8231_FIELD_GPIO_DIR2] = REG_FIELD(RTL8231_REG_PIN_HI_CFG, 5, 9),
+	[RTL8231_FIELD_GPIO_DATA0] = REG_FIELD(RTL8231_REG_GPIO_DATA0, 0, 15),
+	[RTL8231_FIELD_GPIO_DATA1] = REG_FIELD(RTL8231_REG_GPIO_DATA1, 0, 15),
+	[RTL8231_FIELD_GPIO_DATA2] = REG_FIELD(RTL8231_REG_GPIO_DATA2, 0, 4),
+};
+
+struct rtl8231_function {
+	const char *name;
+	unsigned int ngroups;
+	const char **groups;
+};
+
+struct rtl8231_pin_ctrl {
+	/* Pin controller */
+	struct pinctrl_desc pctl_desc;
+	unsigned int nfunctions;
+	struct rtl8231_function *functions;
+	struct regmap *map;
+	/* GPIO controller */
+	struct gpio_chip gc;
+	struct regmap_field *fields[RTL8231_FIELD_GPIO_MAX];
+};
+
+/*
+ * Pin controller functionality
+ */
+static const char * const rtl8231_pin_function_names[] = {
+	"gpio",
+	"led",
+	"pwm",
+};
+
+enum rtl8231_pin_function {
+	RTL8231_PIN_FUNCTION_GPIO = BIT(0),
+	RTL8231_PIN_FUNCTION_LED = BIT(1),
+	RTL8231_PIN_FUNCTION_PWM = BIT(2),
+};
+
+struct rtl8231_pin_desc {
+	unsigned int number;
+	const char *name;
+	enum rtl8231_pin_function functions;
+	u8 reg;
+	u8 offset;
+	u8 gpio_function_value;
+};
+
+#define RTL8231_PIN(_num, _func, _reg, _fld, _val)		\
+	{							\
+		.number = _num,					\
+		.name = "gpio" #_num,				\
+		.functions = RTL8231_PIN_FUNCTION_GPIO | _func,	\
+		.reg = _reg,					\
+		.offset = _fld,					\
+		.gpio_function_value = _val,			\
+	}
+#define RTL8231_GPIO_PIN(_num)					\
+	RTL8231_PIN(_num, 0, 0, 0, 0)
+#define RTL8231_LED_PIN(_num, _reg, _fld)			\
+	RTL8231_PIN(_num, RTL8231_PIN_FUNCTION_LED, _reg, _fld, RTL8231_PIN_MODE_GPIO)
+#define RTL8231_PWM_PIN(_num, _reg, _fld)			\
+	RTL8231_PIN(_num, RTL8231_PIN_FUNCTION_PWM, _reg, _fld, 0)
+
+/* Pins always support GPIO, and may support one alternate function */
+static const struct rtl8231_pin_desc rtl8231_pins[RTL8231_NUM_GPIOS] = {
+	RTL8231_LED_PIN(0, RTL8231_REG_PIN_MODE0, 0),
+	RTL8231_LED_PIN(1, RTL8231_REG_PIN_MODE0, 1),
+	RTL8231_LED_PIN(2, RTL8231_REG_PIN_MODE0, 2),
+	RTL8231_LED_PIN(3, RTL8231_REG_PIN_MODE0, 3),
+	RTL8231_LED_PIN(4, RTL8231_REG_PIN_MODE0, 4),
+	RTL8231_LED_PIN(5, RTL8231_REG_PIN_MODE0, 5),
+	RTL8231_LED_PIN(6, RTL8231_REG_PIN_MODE0, 6),
+	RTL8231_LED_PIN(7, RTL8231_REG_PIN_MODE0, 7),
+	RTL8231_LED_PIN(8, RTL8231_REG_PIN_MODE0, 8),
+	RTL8231_LED_PIN(9, RTL8231_REG_PIN_MODE0, 9),
+	RTL8231_LED_PIN(10, RTL8231_REG_PIN_MODE0, 10),
+	RTL8231_LED_PIN(11, RTL8231_REG_PIN_MODE0, 11),
+	RTL8231_LED_PIN(12, RTL8231_REG_PIN_MODE0, 12),
+	RTL8231_LED_PIN(13, RTL8231_REG_PIN_MODE0, 13),
+	RTL8231_LED_PIN(14, RTL8231_REG_PIN_MODE0, 14),
+	RTL8231_LED_PIN(15, RTL8231_REG_PIN_MODE0, 15),
+	RTL8231_LED_PIN(16, RTL8231_REG_PIN_MODE1, 0),
+	RTL8231_LED_PIN(17, RTL8231_REG_PIN_MODE1, 1),
+	RTL8231_LED_PIN(18, RTL8231_REG_PIN_MODE1, 2),
+	RTL8231_LED_PIN(19, RTL8231_REG_PIN_MODE1, 3),
+	RTL8231_LED_PIN(20, RTL8231_REG_PIN_MODE1, 4),
+	RTL8231_LED_PIN(21, RTL8231_REG_PIN_MODE1, 5),
+	RTL8231_LED_PIN(22, RTL8231_REG_PIN_MODE1, 6),
+	RTL8231_LED_PIN(23, RTL8231_REG_PIN_MODE1, 7),
+	RTL8231_LED_PIN(24, RTL8231_REG_PIN_MODE1, 8),
+	RTL8231_LED_PIN(25, RTL8231_REG_PIN_MODE1, 9),
+	RTL8231_LED_PIN(26, RTL8231_REG_PIN_MODE1, 10),
+	RTL8231_LED_PIN(27, RTL8231_REG_PIN_MODE1, 11),
+	RTL8231_LED_PIN(28, RTL8231_REG_PIN_MODE1, 12),
+	RTL8231_LED_PIN(29, RTL8231_REG_PIN_MODE1, 13),
+	RTL8231_LED_PIN(30, RTL8231_REG_PIN_MODE1, 14),
+	RTL8231_LED_PIN(31, RTL8231_REG_PIN_MODE1, 15),
+	RTL8231_LED_PIN(32, RTL8231_REG_PIN_HI_CFG, 0),
+	RTL8231_LED_PIN(33, RTL8231_REG_PIN_HI_CFG, 1),
+	RTL8231_LED_PIN(34, RTL8231_REG_PIN_HI_CFG, 2),
+	RTL8231_PWM_PIN(35, RTL8231_REG_FUNC1, 3),
+	RTL8231_GPIO_PIN(36),
+};
+
+static int rtl8231_get_groups_count(struct pinctrl_dev *pctldev)
+{
+	return ARRAY_SIZE(rtl8231_pins);
+}
+
+static const char *rtl8231_get_group_name(struct pinctrl_dev *pctldev, unsigned int selector)
+{
+	return rtl8231_pins[selector].name;
+}
+
+static int rtl8231_get_group_pins(struct pinctrl_dev *pctldev, unsigned int selector,
+	const unsigned int **pins, unsigned int *num_pins)
+{
+	if (selector < ARRAY_SIZE(rtl8231_pins)) {
+		*pins = &rtl8231_pins[selector].number;
+		*num_pins = 1;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static const struct pinctrl_ops rtl8231_pinctrl_ops = {
+	.get_groups_count = rtl8231_get_groups_count,
+	.get_group_name = rtl8231_get_group_name,
+	.get_group_pins = rtl8231_get_group_pins,
+	.dt_node_to_map = pinconf_generic_dt_node_to_map_all,
+	.dt_free_map = pinconf_generic_dt_free_map,
+};
+
+static int rtl8231_get_functions_count(struct pinctrl_dev *pctldev)
+{
+	struct rtl8231_pin_ctrl *ctrl = pinctrl_dev_get_drvdata(pctldev);
+
+	return ctrl->nfunctions;
+}
+
+static const char *rtl8231_get_function_name(struct pinctrl_dev *pctldev, unsigned int selector)
+{
+	struct rtl8231_pin_ctrl *ctrl = pinctrl_dev_get_drvdata(pctldev);
+
+	return ctrl->functions[selector].name;
+}
+
+static int rtl8231_get_function_groups(struct pinctrl_dev *pctldev, unsigned int selector,
+	const char * const **groups, unsigned int *num_groups)
+{
+	struct rtl8231_pin_ctrl *ctrl = pinctrl_dev_get_drvdata(pctldev);
+
+	*groups = ctrl->functions[selector].groups;
+	*num_groups = ctrl->functions[selector].ngroups;
+	return 0;
+}
+
+static int rtl8231_set_mux(struct pinctrl_dev *pctldev, unsigned int func_selector,
+	unsigned int group_selector)
+{
+	struct rtl8231_pin_ctrl *ctrl = pinctrl_dev_get_drvdata(pctldev);
+	const struct rtl8231_pin_desc *desc = &rtl8231_pins[group_selector];
+	unsigned int func_flag = BIT(func_selector);
+	unsigned int function_mask;
+	unsigned int gpio_function;
+	int err = 0;
+
+	if (!(desc->functions & func_flag))
+		return -EINVAL;
+
+	function_mask = BIT(desc->offset);
+	gpio_function = desc->gpio_function_value << desc->offset;
+
+	switch (func_flag) {
+	case RTL8231_PIN_FUNCTION_LED:
+	case RTL8231_PIN_FUNCTION_PWM:
+		err = regmap_update_bits(ctrl->map, desc->reg, function_mask, ~gpio_function);
+		break;
+	case RTL8231_PIN_FUNCTION_GPIO:
+		err = regmap_update_bits(ctrl->map, desc->reg, function_mask, gpio_function);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return err;
+}
+
+static int rtl8231_gpio_request_enable(struct pinctrl_dev *pctldev,
+	struct pinctrl_gpio_range *range, unsigned int offset)
+{
+	struct rtl8231_pin_ctrl *ctrl = pinctrl_dev_get_drvdata(pctldev);
+	const struct rtl8231_pin_desc *desc = &rtl8231_pins[offset];
+	unsigned int function_mask;
+	unsigned int gpio_function;
+
+	function_mask = BIT(desc->offset);
+	gpio_function = desc->gpio_function_value << desc->offset;
+
+	return regmap_update_bits(ctrl->map, desc->reg, function_mask, gpio_function);
+}
+
+static const struct pinmux_ops rtl8231_pinmux_ops = {
+	.set_mux = rtl8231_set_mux,
+	.get_functions_count = rtl8231_get_functions_count,
+	.get_function_name = rtl8231_get_function_name,
+	.get_function_groups = rtl8231_get_function_groups,
+	.gpio_request_enable = rtl8231_gpio_request_enable,
+	.strict = true
+};
+
+
+static int rtl8231_pinctrl_init_functions(struct device *dev, struct rtl8231_pin_ctrl *ctrl)
+{
+	struct rtl8231_function *function;
+	const char **group_name;
+	unsigned int f_idx;
+	unsigned int pin;
+
+	ctrl->nfunctions = ARRAY_SIZE(rtl8231_pin_function_names);
+	ctrl->functions = devm_kcalloc(dev, ctrl->nfunctions, sizeof(*ctrl->functions), GFP_KERNEL);
+	if (IS_ERR(ctrl->functions)) {
+		dev_err(dev, "failed to allocate pin function descriptors\n");
+		return PTR_ERR(ctrl->functions);
+	}
+
+	for (f_idx = 0; f_idx < ctrl->nfunctions; f_idx++) {
+		function = &ctrl->functions[f_idx];
+		function->name = rtl8231_pin_function_names[f_idx];
+
+		for (pin = 0; pin < ctrl->pctl_desc.npins; pin++)
+			if (rtl8231_pins[pin].functions & BIT(f_idx))
+				function->ngroups++;
+
+		function->groups = devm_kcalloc(dev, function->ngroups,
+			sizeof(*function->groups), GFP_KERNEL);
+		if (IS_ERR(function->groups)) {
+			dev_err(dev, "failed to allocate pin function group names\n");
+			return PTR_ERR(function->groups);
+		}
+
+		group_name = function->groups;
+		for (pin = 0; pin < ctrl->pctl_desc.npins; pin++)
+			if (rtl8231_pins[pin].functions & BIT(f_idx))
+				*group_name++ = rtl8231_pins[pin].name;
+	}
+
+	return 0;
+}
+
+static int rtl8231_pinctrl_init(struct device *dev, struct rtl8231_pin_ctrl *ctrl)
+{
+	struct pinctrl_dev *pctl;
+	struct pinctrl_pin_desc *pins;
+	unsigned int pin;
+	int err = 0;
+
+	ctrl->pctl_desc.name = "rtl8231-pinctrl",
+	ctrl->pctl_desc.owner = THIS_MODULE,
+	ctrl->pctl_desc.pctlops = &rtl8231_pinctrl_ops,
+	ctrl->pctl_desc.pmxops = &rtl8231_pinmux_ops,
+
+	ctrl->pctl_desc.npins = ARRAY_SIZE(rtl8231_pins);
+	pins = devm_kcalloc(dev, ctrl->pctl_desc.npins, sizeof(*pins), GFP_KERNEL);
+	if (IS_ERR(pins)) {
+		dev_err(dev, "failed to allocate pin descriptors\n");
+		return PTR_ERR(pins);
+	}
+	ctrl->pctl_desc.pins = pins;
+
+	for (pin = 0; pin < ctrl->pctl_desc.npins; pin++) {
+		pins[pin].number = rtl8231_pins[pin].number;
+		pins[pin].name = rtl8231_pins[pin].name;
+	}
+
+	err = rtl8231_pinctrl_init_functions(dev, ctrl);
+	if (err)
+		return err;
+
+	err = devm_pinctrl_register_and_init(dev->parent, &ctrl->pctl_desc, ctrl, &pctl);
+	if (err) {
+		dev_err(dev, "failed to register pin controller\n");
+		return err;
+	}
+
+	err = pinctrl_enable(pctl);
+	if (err)
+		dev_err(dev, "failed to enable pin controller\n");
+
+	return err;
+}
+
+/*
+ * GPIO controller functionality
+ */
+static int rtl8231_pin_read(struct rtl8231_pin_ctrl *ctrl, int base, int offset)
+{
+	int field = base + offset / 16;
+	int bit = offset % 16;
+	unsigned int v;
+	int err;
+
+	err = regmap_field_read(ctrl->fields[field], &v);
+	if (err)
+		return err;
+
+	return !!(v & BIT(bit));
+}
+
+static int rtl8231_pin_write(struct rtl8231_pin_ctrl *ctrl, int base, int offset, int val)
+{
+	int field = base + offset / 16;
+	int bit = offset % 16;
+
+	return regmap_field_update_bits(ctrl->fields[field], BIT(bit), val << bit);
+}
+
+static int rtl8231_direction_input(struct gpio_chip *gc, unsigned int offset)
+{
+	struct rtl8231_pin_ctrl *ctrl = gpiochip_get_data(gc);
+
+	return rtl8231_pin_write(ctrl, RTL8231_FIELD_GPIO_DIR0, offset, RTL8231_GPIO_DIR_IN);
+}
+
+static int rtl8231_direction_output(struct gpio_chip *gc, unsigned int offset, int value)
+{
+	struct rtl8231_pin_ctrl *ctrl = gpiochip_get_data(gc);
+	int err;
+
+	err = rtl8231_pin_write(ctrl, RTL8231_FIELD_GPIO_DIR0, offset, RTL8231_GPIO_DIR_OUT);
+	if (err)
+		return err;
+
+	return rtl8231_pin_write(ctrl, RTL8231_FIELD_GPIO_DATA0, offset, value);
+}
+
+static int rtl8231_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+	struct rtl8231_pin_ctrl *ctrl = gpiochip_get_data(gc);
+
+	return rtl8231_pin_read(ctrl, RTL8231_FIELD_GPIO_DIR0, offset);
+}
+
+static int rtl8231_gpio_get(struct gpio_chip *gc, unsigned int offset)
+{
+	struct rtl8231_pin_ctrl *ctrl = gpiochip_get_data(gc);
+
+	return rtl8231_pin_read(ctrl, RTL8231_FIELD_GPIO_DATA0, offset);
+}
+
+static void rtl8231_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
+{
+	struct rtl8231_pin_ctrl *ctrl = gpiochip_get_data(gc);
+
+	rtl8231_pin_write(ctrl, RTL8231_FIELD_GPIO_DATA0, offset, value);
+}
+
+static int rtl8231_gpio_get_multiple(struct gpio_chip *gc,
+	unsigned long *mask, unsigned long *bits)
+{
+	struct rtl8231_pin_ctrl *ctrl = gpiochip_get_data(gc);
+	unsigned long sub_mask, bit_value;
+	struct regmap_field **field;
+	unsigned int reg_value;
+	int offset, shift;
+	int read;
+	int err;
+
+	field = &ctrl->fields[RTL8231_FIELD_GPIO_DATA0];
+
+	for (read = 0; read < gc->ngpio; field++, read += 16) {
+		shift = read % BITS_PER_TYPE(*bits);
+		offset = read / BITS_PER_TYPE(*bits);
+		sub_mask = mask[offset] & (0xffffUL << shift);
+		if (sub_mask) {
+			err = regmap_field_read(*field, &reg_value);
+			if (err)
+				return err;
+			bit_value = ((unsigned long) reg_value) << shift;
+			bits[offset] = (bits[offset] & ~sub_mask) | (bit_value & sub_mask);
+		}
+	}
+
+	return err;
+}
+
+static void rtl8231_gpio_set_multiple(struct gpio_chip *gc,
+	unsigned long *mask, unsigned long *bits)
+{
+	struct rtl8231_pin_ctrl *ctrl = gpiochip_get_data(gc);
+	unsigned long sub_mask, value;
+	struct regmap_field **field;
+	int offset, shift;
+	int read;
+
+	field = &ctrl->fields[RTL8231_FIELD_GPIO_DATA0];
+
+	for (read = 0; read < gc->ngpio; field++, read += 16) {
+		shift = read % BITS_PER_TYPE(*bits);
+		offset = read / BITS_PER_TYPE(*bits);
+		sub_mask = (mask[offset] >> shift) & 0xffff;
+		if (sub_mask) {
+			value = bits[offset] >> shift;
+			regmap_field_update_bits(*field, sub_mask, value);
+		}
+	}
+}
+
+static int rtl8231_pinctrl_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct rtl8231_pin_ctrl *ctrl;
+	int err;
+
+	ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
+	if (!ctrl)
+		return -ENOMEM;
+
+	ctrl->map = dev_get_regmap(dev->parent, NULL);
+	if (IS_ERR_OR_NULL(ctrl->map)) {
+		dev_err(dev, "failed to retrieve regmap\n");
+		if (!ctrl->map)
+			return -ENODEV;
+		else
+			return PTR_ERR(ctrl->map);
+	}
+
+	err = devm_regmap_field_bulk_alloc(dev, ctrl->map, ctrl->fields, rtl8231_gpio_fields,
+		ARRAY_SIZE(ctrl->fields));
+	if (err) {
+		dev_err(dev, "unable to allocate gpio regmap fields\n");
+		return err;
+	}
+
+	err = rtl8231_pinctrl_init(dev, ctrl);
+	if (err)
+		return err;
+
+	ctrl->gc.base = -1;
+	ctrl->gc.ngpio = RTL8231_NUM_GPIOS;
+	ctrl->gc.label = pdev->name;
+	ctrl->gc.owner = THIS_MODULE;
+	ctrl->gc.can_sleep = true;
+	ctrl->gc.parent = dev->parent;
+
+	ctrl->gc.set = rtl8231_gpio_set;
+	ctrl->gc.set_multiple = rtl8231_gpio_set_multiple;
+	ctrl->gc.get = rtl8231_gpio_get;
+	ctrl->gc.get_multiple = rtl8231_gpio_get_multiple;
+	ctrl->gc.direction_input = rtl8231_direction_input;
+	ctrl->gc.direction_output = rtl8231_direction_output;
+	ctrl->gc.get_direction = rtl8231_get_direction;
+	ctrl->gc.request = gpiochip_generic_request;
+	ctrl->gc.free = gpiochip_generic_free;
+
+	return devm_gpiochip_add_data(dev, &ctrl->gc, ctrl);
+}
+
+static struct platform_driver rtl8231_pinctrl_driver = {
+	.driver = {
+		.name = "rtl8231-pinctrl",
+	},
+	.probe = rtl8231_pinctrl_probe,
+};
+module_platform_driver(rtl8231_pinctrl_driver);
+
+MODULE_AUTHOR("Sander Vanheule <sander@svanheule.net>");
+MODULE_DESCRIPTION("Realtek RTL8231 pin control and GPIO support");
+MODULE_LICENSE("GPL v2");