--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2024 Nuvoton Technology Corp.
+ */
+
+#include <dm.h>
+#include <asm/gpio.h>
+#include <linux/io.h>
+
+#define MAX_NR_HW_SGPIO 64
+#define NPCM_CLK_MHZ 8000000
+
+#define NPCM_IOXCFG1 0x2A
+
+#define NPCM_IOXCTS 0x28
+#define NPCM_IOXCTS_IOXIF_EN BIT(7)
+#define NPCM_IOXCTS_RD_MODE GENMASK(2, 1)
+#define NPCM_IOXCTS_RD_MODE_PERIODIC BIT(2)
+
+#define NPCM_IOXCFG2 0x2B
+#define NPCM_IOXCFG2_PORT GENMASK(3, 0)
+
+#define GPIO_BANK(x) ((x) / 8)
+#define GPIO_BIT(x) ((x) % 8)
+
+struct npcm_sgpio_priv {
+ void __iomem *base;
+ u32 nin_sgpio;
+ u32 nout_sgpio;
+ u32 in_port;
+ u32 out_port;
+};
+
+struct npcm_sgpio_bank {
+ u8 rdata_reg;
+ u8 wdata_reg;
+ u8 event_config;
+ u8 event_status;
+};
+
+enum npcm_sgpio_reg {
+ READ_DATA,
+ WRITE_DATA,
+ EVENT_CFG,
+ EVENT_STS,
+};
+
+static const struct npcm_sgpio_bank npcm_sgpio_banks[] = {
+ {
+ .wdata_reg = 0x00,
+ .rdata_reg = 0x08,
+ .event_config = 0x10,
+ .event_status = 0x20,
+ },
+ {
+ .wdata_reg = 0x01,
+ .rdata_reg = 0x09,
+ .event_config = 0x12,
+ .event_status = 0x21,
+ },
+ {
+ .wdata_reg = 0x02,
+ .rdata_reg = 0x0a,
+ .event_config = 0x14,
+ .event_status = 0x22,
+ },
+ {
+ .wdata_reg = 0x03,
+ .rdata_reg = 0x0b,
+ .event_config = 0x16,
+ .event_status = 0x23,
+ },
+ {
+ .wdata_reg = 0x04,
+ .rdata_reg = 0x0c,
+ .event_config = 0x18,
+ .event_status = 0x24,
+ },
+ {
+ .wdata_reg = 0x05,
+ .rdata_reg = 0x0d,
+ .event_config = 0x1a,
+ .event_status = 0x25,
+ },
+ {
+ .wdata_reg = 0x06,
+ .rdata_reg = 0x0e,
+ .event_config = 0x1c,
+ .event_status = 0x26,
+ },
+ {
+ .wdata_reg = 0x07,
+ .rdata_reg = 0x0f,
+ .event_config = 0x1e,
+ .event_status = 0x27,
+ },
+};
+
+static void __iomem *bank_reg(struct npcm_sgpio_priv *gpio,
+ const struct npcm_sgpio_bank *bank,
+ const enum npcm_sgpio_reg reg)
+{
+ switch (reg) {
+ case READ_DATA:
+ return gpio->base + bank->rdata_reg;
+ case WRITE_DATA:
+ return gpio->base + bank->wdata_reg;
+ case EVENT_CFG:
+ return gpio->base + bank->event_config;
+ case EVENT_STS:
+ return gpio->base + bank->event_status;
+ default:
+ /* actually if code runs to here, it's an error case */
+ printf("Getting here is an error condition\n");
+ return NULL;
+ }
+}
+
+static const struct npcm_sgpio_bank *offset_to_bank(unsigned int offset)
+{
+ unsigned int bank = GPIO_BANK(offset);
+
+ return &npcm_sgpio_banks[bank];
+}
+
+static int npcm_sgpio_direction_input(struct udevice *dev, unsigned int offset)
+{
+ struct npcm_sgpio_priv *priv = dev_get_priv(dev);
+
+ if (offset < priv->nout_sgpio) {
+ printf("Error: Offset %d is a output pin\n", offset);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int npcm_sgpio_direction_output(struct udevice *dev, unsigned int offset,
+ int value)
+{
+ struct npcm_sgpio_priv *priv = dev_get_priv(dev);
+ const struct npcm_sgpio_bank *bank = offset_to_bank(offset);
+ void __iomem *addr;
+ u8 reg = 0;
+
+ if (offset >= priv->nout_sgpio) {
+ printf("Error: Offset %d is a input pin\n", offset);
+ return -EINVAL;
+ }
+
+ addr = bank_reg(priv, bank, WRITE_DATA);
+ reg = ioread8(addr);
+
+ if (value)
+ reg |= BIT(GPIO_BIT(offset));
+ else
+ reg &= ~BIT(GPIO_BIT(offset));
+
+ iowrite8(reg, addr);
+
+ return 0;
+}
+
+static int npcm_sgpio_get_value(struct udevice *dev, unsigned int offset)
+{
+ struct npcm_sgpio_priv *priv = dev_get_priv(dev);
+ const struct npcm_sgpio_bank *bank;
+ void __iomem *addr;
+ u8 reg;
+
+ if (offset < priv->nout_sgpio) {
+ bank = offset_to_bank(offset);
+ addr = bank_reg(priv, bank, WRITE_DATA);
+ } else {
+ offset -= priv->nout_sgpio;
+ bank = offset_to_bank(offset);
+ addr = bank_reg(priv, bank, READ_DATA);
+ }
+
+ reg = ioread8(addr);
+
+ return !!(reg & BIT(GPIO_BIT(offset)));
+}
+
+static int npcm_sgpio_set_value(struct udevice *dev, unsigned int offset,
+ int value)
+{
+ return npcm_sgpio_direction_output(dev, offset, value);
+}
+
+static int npcm_sgpio_get_function(struct udevice *dev, unsigned int offset)
+{
+ struct npcm_sgpio_priv *priv = dev_get_priv(dev);
+
+ if (offset < priv->nout_sgpio)
+ return GPIOF_OUTPUT;
+
+ return GPIOF_INPUT;
+}
+
+static void npcm_sgpio_setup_enable(struct npcm_sgpio_priv *gpio, bool enable)
+{
+ u8 reg;
+
+ reg = ioread8(gpio->base + NPCM_IOXCTS);
+ reg = (reg & ~NPCM_IOXCTS_RD_MODE) | NPCM_IOXCTS_RD_MODE_PERIODIC;
+
+ if (enable)
+ reg |= NPCM_IOXCTS_IOXIF_EN;
+ else
+ reg &= ~NPCM_IOXCTS_IOXIF_EN;
+
+ iowrite8(reg, gpio->base + NPCM_IOXCTS);
+}
+
+static int npcm_sgpio_init_port(struct udevice *dev)
+{
+ struct npcm_sgpio_priv *priv = dev_get_priv(dev);
+ u8 in_port, out_port, set_port, reg, set_clk;
+
+ npcm_sgpio_setup_enable(priv, false);
+
+ in_port = GPIO_BANK(priv->nin_sgpio);
+ if (GPIO_BIT(priv->nin_sgpio) > 0)
+ in_port += 1;
+
+ out_port = GPIO_BANK(priv->nout_sgpio);
+ if (GPIO_BIT(priv->nout_sgpio) > 0)
+ out_port += 1;
+
+ priv->in_port = in_port;
+ priv->out_port = out_port;
+
+ set_port = (out_port & NPCM_IOXCFG2_PORT) << 4 | (in_port & NPCM_IOXCFG2_PORT);
+ set_clk = 0x07;
+
+ iowrite8(set_port, priv->base + NPCM_IOXCFG2);
+ iowrite8(set_clk, priv->base + NPCM_IOXCFG1);
+
+ reg = ioread8(priv->base + NPCM_IOXCFG2);
+
+ return reg == set_port ? 0 : -EINVAL;
+}
+
+static const struct dm_gpio_ops npcm_sgpio_ops = {
+ .direction_input = npcm_sgpio_direction_input,
+ .direction_output = npcm_sgpio_direction_output,
+ .get_value = npcm_sgpio_get_value,
+ .set_value = npcm_sgpio_set_value,
+ .get_function = npcm_sgpio_get_function,
+};
+
+static int npcm_sgpio_probe(struct udevice *dev)
+{
+ struct npcm_sgpio_priv *priv = dev_get_priv(dev);
+ struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+ int rc;
+
+ priv->base = dev_read_addr_ptr(dev);
+ ofnode_read_u32(dev_ofnode(dev), "nuvoton,input-ngpios", &priv->nin_sgpio);
+ ofnode_read_u32(dev_ofnode(dev), "nuvoton,output-ngpios", &priv->nout_sgpio);
+
+ if (priv->nin_sgpio > MAX_NR_HW_SGPIO || priv->nout_sgpio > MAX_NR_HW_SGPIO)
+ return -EINVAL;
+
+ rc = npcm_sgpio_init_port(dev);
+ if (rc < 0)
+ return rc;
+
+ uc_priv->gpio_count = priv->nin_sgpio + priv->nout_sgpio;
+ uc_priv->bank_name = dev->name;
+
+ npcm_sgpio_setup_enable(priv, true);
+
+ return 0;
+}
+
+static const struct udevice_id npcm_sgpio_match[] = {
+ { .compatible = "nuvoton,npcm845-sgpio" },
+ { .compatible = "nuvoton,npcm750-sgpio" },
+ { }
+};
+
+U_BOOT_DRIVER(npcm_sgpio) = {
+ .name = "npcm_sgpio",
+ .id = UCLASS_GPIO,
+ .of_match = npcm_sgpio_match,
+ .probe = npcm_sgpio_probe,
+ .priv_auto = sizeof(struct npcm_sgpio_priv),
+ .ops = &npcm_sgpio_ops,
+};