diff --git a/drivers/gpio/gpio-aspeed-sgpio.c b/drivers/gpio/gpio-aspeed-sgpio.c
index 64e54f8c30d2d6f4371d8f1fc6ce16d54b4abae0..8f6bacd23e13e2a9f60a8620eb5847253abf5b52 100644
--- a/drivers/gpio/gpio-aspeed-sgpio.c
+++ b/drivers/gpio/gpio-aspeed-sgpio.c
@@ -17,23 +17,15 @@
 #include <linux/spinlock.h>
 #include <linux/string.h>
 
-/*
- * MAX_NR_HW_GPIO represents the number of actual hardware-supported GPIOs (ie,
- * slots within the clocked serial GPIO data). Since each HW GPIO is both an
- * input and an output, we provide MAX_NR_HW_GPIO * 2 lines on our gpiochip
- * device.
- *
- * We use SGPIO_OUTPUT_OFFSET to define the split between the inputs and
- * outputs; the inputs start at line 0, the outputs start at OUTPUT_OFFSET.
- */
-#define MAX_NR_HW_SGPIO			80
-#define SGPIO_OUTPUT_OFFSET		MAX_NR_HW_SGPIO
-
 #define ASPEED_SGPIO_CTRL		0x54
 
-#define ASPEED_SGPIO_PINS_MASK		GENMASK(9, 6)
 #define ASPEED_SGPIO_CLK_DIV_MASK	GENMASK(31, 16)
 #define ASPEED_SGPIO_ENABLE		BIT(0)
+#define ASPEED_SGPIO_PINS_SHIFT		6
+
+struct aspeed_sgpio_pdata {
+	const u32 pin_mask;
+};
 
 struct aspeed_sgpio {
 	struct gpio_chip chip;
@@ -41,7 +33,6 @@ struct aspeed_sgpio {
 	spinlock_t lock;
 	void __iomem *base;
 	int irq;
-	int n_sgpio;
 };
 
 struct aspeed_sgpio_bank {
@@ -75,7 +66,13 @@ static const struct aspeed_sgpio_bank aspeed_sgpio_banks[] = {
 		.val_regs = 0x0038,
 		.rdata_reg = 0x0078,
 		.irq_regs = 0x003C,
-		.names = { "I", "J" },
+		.names = { "I", "J", "K", "L" },
+	},
+	{
+		.val_regs = 0x0090,
+		.rdata_reg = 0x007C,
+		.irq_regs = 0x0094,
+		.names = { "M", "N", "O", "P" },
 	},
 };
 
@@ -121,9 +118,9 @@ static void __iomem *bank_reg(struct aspeed_sgpio *gpio,
 	}
 }
 
-#define GPIO_BANK(x)    ((x % SGPIO_OUTPUT_OFFSET) >> 5)
-#define GPIO_OFFSET(x)  ((x % SGPIO_OUTPUT_OFFSET) & 0x1f)
-#define GPIO_BIT(x)     BIT(GPIO_OFFSET(x))
+#define GPIO_BANK(x)    ((x) >> 6)
+#define GPIO_OFFSET(x)  ((x) & GENMASK(5, 0))
+#define GPIO_BIT(x)     BIT(GPIO_OFFSET(x) >> 1)
 
 static const struct aspeed_sgpio_bank *to_bank(unsigned int offset)
 {
@@ -138,39 +135,25 @@ static const struct aspeed_sgpio_bank *to_bank(unsigned int offset)
 static int aspeed_sgpio_init_valid_mask(struct gpio_chip *gc,
 		unsigned long *valid_mask, unsigned int ngpios)
 {
-	struct aspeed_sgpio *sgpio = gpiochip_get_data(gc);
-	int n = sgpio->n_sgpio;
-	int c = SGPIO_OUTPUT_OFFSET - n;
-
-	WARN_ON(ngpios < MAX_NR_HW_SGPIO * 2);
-
-	/* input GPIOs in the lower range */
-	bitmap_set(valid_mask, 0, n);
-	bitmap_clear(valid_mask, n, c);
-
-	/* output GPIOS above SGPIO_OUTPUT_OFFSET */
-	bitmap_set(valid_mask, SGPIO_OUTPUT_OFFSET, n);
-	bitmap_clear(valid_mask, SGPIO_OUTPUT_OFFSET + n, c);
-
+	bitmap_set(valid_mask, 0, ngpios);
 	return 0;
 }
 
 static void aspeed_sgpio_irq_init_valid_mask(struct gpio_chip *gc,
 		unsigned long *valid_mask, unsigned int ngpios)
 {
-	struct aspeed_sgpio *sgpio = gpiochip_get_data(gc);
-	int n = sgpio->n_sgpio;
+	unsigned int i;
 
-	WARN_ON(ngpios < MAX_NR_HW_SGPIO * 2);
-
-	/* input GPIOs in the lower range */
-	bitmap_set(valid_mask, 0, n);
-	bitmap_clear(valid_mask, n, ngpios - n);
+	/* input GPIOs are even bits */
+	for (i = 0; i < ngpios; i++) {
+		if (i % 2)
+			clear_bit(i, valid_mask);
+	}
 }
 
 static bool aspeed_sgpio_is_input(unsigned int offset)
 {
-	return offset < SGPIO_OUTPUT_OFFSET;
+	return !(offset % 2);
 }
 
 static int aspeed_sgpio_get(struct gpio_chip *gc, unsigned int offset)
@@ -466,9 +449,18 @@ static int aspeed_sgpio_setup_irqs(struct aspeed_sgpio *gpio,
 	return 0;
 }
 
+static const struct aspeed_sgpio_pdata ast2400_sgpio_pdata = {
+	.pin_mask = GENMASK(9, 6),
+};
+
+static const struct aspeed_sgpio_pdata ast2600_sgpiom_pdata = {
+	.pin_mask = GENMASK(10, 6),
+};
+
 static const struct of_device_id aspeed_sgpio_of_table[] = {
-	{ .compatible = "aspeed,ast2400-sgpio" },
-	{ .compatible = "aspeed,ast2500-sgpio" },
+	{ .compatible = "aspeed,ast2400-sgpio", .data = &ast2400_sgpio_pdata, },
+	{ .compatible = "aspeed,ast2500-sgpio", .data = &ast2400_sgpio_pdata, },
+	{ .compatible = "aspeed,ast2600-sgpiom", .data = &ast2600_sgpiom_pdata, },
 	{}
 };
 
@@ -476,10 +468,11 @@ MODULE_DEVICE_TABLE(of, aspeed_sgpio_of_table);
 
 static int __init aspeed_sgpio_probe(struct platform_device *pdev)
 {
+	u32 nr_gpios, sgpio_freq, sgpio_clk_div, gpio_cnt_regval, pin_mask;
+	const struct aspeed_sgpio_pdata *pdata;
 	struct aspeed_sgpio *gpio;
-	u32 nr_gpios, sgpio_freq, sgpio_clk_div;
-	int rc;
 	unsigned long apb_freq;
+	int rc;
 
 	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
 	if (!gpio)
@@ -489,16 +482,17 @@ static int __init aspeed_sgpio_probe(struct platform_device *pdev)
 	if (IS_ERR(gpio->base))
 		return PTR_ERR(gpio->base);
 
+	pdata = device_get_match_data(&pdev->dev);
+	if (!pdata)
+		return -EINVAL;
+
+	pin_mask = pdata->pin_mask;
+
 	rc = of_property_read_u32(pdev->dev.of_node, "ngpios", &nr_gpios);
 	if (rc < 0) {
 		dev_err(&pdev->dev, "Could not read ngpios property\n");
 		return -EINVAL;
-	} else if (nr_gpios > MAX_NR_HW_SGPIO) {
-		dev_err(&pdev->dev, "Number of GPIOs exceeds the maximum of %d: %d\n",
-			MAX_NR_HW_SGPIO, nr_gpios);
-		return -EINVAL;
 	}
-	gpio->n_sgpio = nr_gpios;
 
 	rc = of_property_read_u32(pdev->dev.of_node, "bus-frequency", &sgpio_freq);
 	if (rc < 0) {
@@ -531,15 +525,14 @@ static int __init aspeed_sgpio_probe(struct platform_device *pdev)
 	if (sgpio_clk_div > (1 << 16) - 1)
 		return -EINVAL;
 
-	iowrite32(FIELD_PREP(ASPEED_SGPIO_CLK_DIV_MASK, sgpio_clk_div) |
-		  FIELD_PREP(ASPEED_SGPIO_PINS_MASK, (nr_gpios / 8)) |
-		  ASPEED_SGPIO_ENABLE,
-		  gpio->base + ASPEED_SGPIO_CTRL);
+	gpio_cnt_regval = ((nr_gpios / 8) << ASPEED_SGPIO_PINS_SHIFT) & pin_mask;
+	iowrite32(FIELD_PREP(ASPEED_SGPIO_CLK_DIV_MASK, sgpio_clk_div) | gpio_cnt_regval |
+		  ASPEED_SGPIO_ENABLE, gpio->base + ASPEED_SGPIO_CTRL);
 
 	spin_lock_init(&gpio->lock);
 
 	gpio->chip.parent = &pdev->dev;
-	gpio->chip.ngpio = MAX_NR_HW_SGPIO * 2;
+	gpio->chip.ngpio = nr_gpios * 2;
 	gpio->chip.init_valid_mask = aspeed_sgpio_init_valid_mask;
 	gpio->chip.direction_input = aspeed_sgpio_dir_in;
 	gpio->chip.direction_output = aspeed_sgpio_dir_out;