[RFC,v2,03/13] gpio: add nexell driver

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 1de6f52..febda89 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -421,4 +421,13 @@  config MT7621_GPIO
 	help
 	  Say yes here to support MediaTek MT7621 compatible GPIOs.
 
+config NX_GPIO
+	bool "Nexell GPIO driver"
+	depends on DM_GPIO
+	help
+	  Support GPIO access on Nexell SoCs. The GPIOs are arranged into
+	  a number of banks (different for each SoC type) each with 32 GPIOs.
+	  The GPIOs for a device are defined in the device tree with one node
+	  for each bank.
+
 endmenu
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 449046b..cb20478 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -64,4 +64,5 @@  obj-$(CONFIG_$(SPL_)PCF8575_GPIO)	+= pcf8575_gpio.o
 obj-$(CONFIG_PM8916_GPIO)	+= pm8916_gpio.o
 obj-$(CONFIG_MT7621_GPIO)	+= mt7621_gpio.o
 obj-$(CONFIG_MSCC_SGPIO)	+= mscc_sgpio.o
+obj-$(CONFIG_NX_GPIO)		+= nx_gpio.o
 obj-$(CONFIG_SIFIVE_GPIO)	+= sifive-gpio.o
diff --git a/drivers/gpio/nx_gpio.c b/drivers/gpio/nx_gpio.c
new file mode 100644
index 0000000..86472f6
--- /dev/null
+++ b/drivers/gpio/nx_gpio.c
@@ -0,0 +1,252 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2016 Nexell
+ * DeokJin, Lee <truevirtue at nexell.co.kr>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <malloc.h>
+#include <fdtdec.h>
+#include <asm/io.h>
+#include <asm/gpio.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct nx_gpio_regs {
+	u32	data;		/* Data register */
+	u32	outputenb;	/* Output Enable register */
+	u32	detmode[2];	/* Detect Mode Register */
+	u32	intenb;		/* Interrupt Enable Register */
+	u32	det;		/* Event Detect Register */
+	u32	pad;		/* Pad Status Register */
+};
+
+struct nx_alive_gpio_regs {
+	u32	pwrgate;	/* Power Gating Register */
+	u32	reserved0[28];	/* Reserved0 */
+	u32	outputenb_reset;/* Alive GPIO Output Enable Reset Register */
+	u32	outputenb;	/* Alive GPIO Output Enable Register */
+	u32	outputenb_read; /* Alive GPIO Output Read Register */
+	u32	reserved1[3];	/* Reserved1 */
+	u32	pad_reset;	/* Alive GPIO Output Reset Register */
+	u32	data;		/* Alive GPIO Output Register */
+	u32	pad_read;	/* Alive GPIO Pad Read Register */
+	u32	reserved2[33];	/* Reserved2 */
+	u32	pad;		/* Alive GPIO Input Value Register */
+};
+
+struct nx_gpio_platdata {
+	void *regs;
+	int gpio_count;
+	const char *bank_name;
+};
+
+static int nx_alive_gpio_is_check(struct udevice *dev)
+{
+	struct nx_gpio_platdata *plat = dev_get_platdata(dev);
+	const char *bank_name = plat->bank_name;
+
+	if (!strcmp(bank_name, "gpio_alv"))
+		return 1;
+
+	return 0;
+}
+
+static int nx_alive_gpio_direction_input(struct udevice *dev, unsigned int pin)
+{
+	struct nx_gpio_platdata *plat = dev_get_platdata(dev);
+	struct nx_alive_gpio_regs *const regs = plat->regs;
+
+	setbits_le32(&regs->outputenb_reset, 1 << pin);
+
+	return 0;
+}
+
+static int nx_alive_gpio_direction_output(struct udevice *dev, unsigned int pin,
+					  int val)
+{
+	struct nx_gpio_platdata *plat = dev_get_platdata(dev);
+	struct nx_alive_gpio_regs *const regs = plat->regs;
+
+	if (val)
+		setbits_le32(&regs->data, 1 << pin);
+	else
+		setbits_le32(&regs->pad_reset, 1 << pin);
+
+	setbits_le32(&regs->outputenb, 1 << pin);
+
+	return 0;
+}
+
+static int nx_alive_gpio_get_value(struct udevice *dev, unsigned int pin)
+{
+	struct nx_gpio_platdata *plat = dev_get_platdata(dev);
+	struct nx_alive_gpio_regs *const regs = plat->regs;
+	unsigned int mask = 1UL << pin;
+	unsigned int value;
+
+	value = (readl(&regs->pad_read) & mask) >> pin;
+
+	return value;
+}
+
+static int nx_alive_gpio_set_value(struct udevice *dev, unsigned int pin,
+				   int val)
+{
+	struct nx_gpio_platdata *plat = dev_get_platdata(dev);
+	struct nx_alive_gpio_regs *const regs = plat->regs;
+
+	if (val)
+		setbits_le32(&regs->data, 1 << pin);
+	else
+		clrbits_le32(&regs->pad_reset, 1 << pin);
+
+	return 0;
+}
+
+static int nx_alive_gpio_get_function(struct udevice *dev, unsigned int pin)
+{
+	struct nx_gpio_platdata *plat = dev_get_platdata(dev);
+	struct nx_alive_gpio_regs *const regs = plat->regs;
+	unsigned int mask = (1UL << pin);
+	unsigned int output;
+
+	output = readl(&regs->outputenb_read) & mask;
+
+	if (output)
+		return GPIOF_OUTPUT;
+	else
+		return GPIOF_INPUT;
+}
+
+static int nx_gpio_direction_input(struct udevice *dev, unsigned int pin)
+{
+	struct nx_gpio_platdata *plat = dev_get_platdata(dev);
+	struct nx_gpio_regs *const regs = plat->regs;
+
+	if (nx_alive_gpio_is_check(dev))
+		return nx_alive_gpio_direction_input(dev, pin);
+
+	clrbits_le32(&regs->outputenb, 1 << pin);
+
+	return 0;
+}
+
+static int nx_gpio_direction_output(struct udevice *dev, unsigned int pin,
+				    int val)
+{
+	struct nx_gpio_platdata *plat = dev_get_platdata(dev);
+	struct nx_gpio_regs *const regs = plat->regs;
+
+	if (nx_alive_gpio_is_check(dev))
+		return nx_alive_gpio_direction_output(dev, pin, val);
+
+	if (val)
+		setbits_le32(&regs->data, 1 << pin);
+	else
+		clrbits_le32(&regs->data, 1 << pin);
+
+	setbits_le32(&regs->outputenb, 1 << pin);
+
+	return 0;
+}
+
+static int nx_gpio_get_value(struct udevice *dev, unsigned int pin)
+{
+	struct nx_gpio_platdata *plat = dev_get_platdata(dev);
+	struct nx_gpio_regs *const regs = plat->regs;
+	unsigned int mask = 1UL << pin;
+	unsigned int value;
+
+	if (nx_alive_gpio_is_check(dev))
+		return nx_alive_gpio_get_value(dev, pin);
+
+	value = (readl(&regs->pad) & mask) >> pin;
+
+	return value;
+}
+
+static int nx_gpio_set_value(struct udevice *dev, unsigned int pin, int val)
+{
+	struct nx_gpio_platdata *plat = dev_get_platdata(dev);
+	struct nx_gpio_regs *const regs = plat->regs;
+
+	if (nx_alive_gpio_is_check(dev))
+		return nx_alive_gpio_set_value(dev, pin, val);
+
+	if (val)
+		setbits_le32(&regs->data, 1 << pin);
+	else
+		clrbits_le32(&regs->data, 1 << pin);
+
+	return 0;
+}
+
+static int nx_gpio_get_function(struct udevice *dev, unsigned int pin)
+{
+	struct nx_gpio_platdata *plat = dev_get_platdata(dev);
+	struct nx_gpio_regs *const regs = plat->regs;
+	unsigned int mask = (1UL << pin);
+	unsigned int output;
+
+	if (nx_alive_gpio_is_check(dev))
+		return nx_alive_gpio_get_function(dev, pin);
+
+	output = readl(&regs->outputenb) & mask;
+
+	if (output)
+		return GPIOF_OUTPUT;
+	else
+		return GPIOF_INPUT;
+}
+
+static int nx_gpio_probe(struct udevice *dev)
+{
+	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+	struct nx_gpio_platdata *plat = dev_get_platdata(dev);
+
+	uc_priv->gpio_count = plat->gpio_count;
+	uc_priv->bank_name = plat->bank_name;
+
+	return 0;
+}
+
+static int nx_gpio_ofdata_to_platdata(struct udevice *dev)
+{
+	struct nx_gpio_platdata *plat = dev_get_platdata(dev);
+
+	plat->regs = map_physmem(devfdt_get_addr(dev),
+				 sizeof(struct nx_gpio_regs),
+				 MAP_NOCACHE);
+	plat->gpio_count = fdtdec_get_int(gd->fdt_blob, dev->node.of_offset,
+					  "nexell,gpio-bank-width", 32);
+	plat->bank_name = fdt_getprop(gd->fdt_blob, dev->node.of_offset,
+				      "gpio-bank-name", NULL);
+
+	return 0;
+}
+
+static const struct dm_gpio_ops nx_gpio_ops = {
+	.direction_input	= nx_gpio_direction_input,
+	.direction_output	= nx_gpio_direction_output,
+	.get_value		= nx_gpio_get_value,
+	.set_value		= nx_gpio_set_value,
+	.get_function		= nx_gpio_get_function,
+};
+
+static const struct udevice_id nx_gpio_ids[] = {
+	{ .compatible = "nexell,nexell-gpio" },
+	{ }
+};
+
+U_BOOT_DRIVER(nx_gpio) = {
+	.name		= "nx_gpio",
+	.id		= UCLASS_GPIO,
+	.of_match	= nx_gpio_ids,
+	.ops		= &nx_gpio_ops,
+	.ofdata_to_platdata = nx_gpio_ofdata_to_platdata,
+	.platdata_auto_alloc_size = sizeof(struct nx_gpio_platdata),
+	.probe		= nx_gpio_probe,
+};