[v5,05/10] gpio: gpio-aspeed-sgpio: Add AST2600 sgpio support

Message ID 20210608102547.4880-6-steven_lee@aspeedtech.com
State New
Headers show
Series
  • ASPEED sgpio driver enhancement.
Related show

Commit Message

Steven Lee June 8, 2021, 10:25 a.m.
AST2600 SoC has 2 SGPIO master interfaces one with 128 pins another one
with 80 pins.
In the current driver, the maximum number of gpio pins of SoC is hardcoded
as 80 and the gpio pin count mask for GPIO Configuration register is
hardcode as GENMASK(9,6). In addition, some functions use the hardcoded
value to calculate the gpio offset.
The patch adds ast2600 compatibles and platform data that includes the
max number of gpio pins supported by ast2600 and gpio pin count mask for
GPIO Configuration register.
The patch also modifies some functions to pass aspeed_sgpio struct for
calculating gpio offset without using the hardcoded value.

Signed-off-by: Steven Lee <steven_lee@aspeedtech.com>
---
 drivers/gpio/gpio-aspeed-sgpio.c | 107 +++++++++++++++++++++----------
 1 file changed, 73 insertions(+), 34 deletions(-)

Comments

Andrew Jeffery June 9, 2021, 12:52 a.m. | #1
On Tue, 8 Jun 2021, at 19:55, Steven Lee wrote:
> AST2600 SoC has 2 SGPIO master interfaces one with 128 pins another one
> with 80 pins.
> In the current driver, the maximum number of gpio pins of SoC is hardcoded
> as 80 and the gpio pin count mask for GPIO Configuration register is
> hardcode as GENMASK(9,6). In addition, some functions use the hardcoded
> value to calculate the gpio offset.
> The patch adds ast2600 compatibles and platform data that includes the
> max number of gpio pins supported by ast2600 and gpio pin count mask for
> GPIO Configuration register.
> The patch also modifies some functions to pass aspeed_sgpio struct for
> calculating gpio offset without using the hardcoded value.
> 
> Signed-off-by: Steven Lee <steven_lee@aspeedtech.com>
> ---
>  drivers/gpio/gpio-aspeed-sgpio.c | 107 +++++++++++++++++++++----------
>  1 file changed, 73 insertions(+), 34 deletions(-)
> 
> diff --git a/drivers/gpio/gpio-aspeed-sgpio.c b/drivers/gpio/gpio-aspeed-sgpio.c
> index 64e54f8c30d2..ea20a0127748 100644
> --- a/drivers/gpio/gpio-aspeed-sgpio.c
> +++ b/drivers/gpio/gpio-aspeed-sgpio.c
> @@ -34,6 +34,12 @@
>  #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;
> +	int max_ngpios;
> +};
>  
>  struct aspeed_sgpio {
>  	struct gpio_chip chip;
> @@ -41,6 +47,7 @@ struct aspeed_sgpio {
>  	spinlock_t lock;
>  	void __iomem *base;
>  	int irq;
> +	int max_ngpios;
>  	int n_sgpio;
>  };
>  
> @@ -75,7 +82,13 @@ 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" },
>  	},
>  };
>  
> @@ -121,15 +134,15 @@ 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(gpio, x)    (((x) % (gpio)->max_ngpios) >> 5)
> +#define GPIO_OFFSET(x)        ((x) & GENMASK(4, 0))
> +#define GPIO_BIT(gpio, x)     BIT(GPIO_OFFSET((x) % (gpio)->max_ngpios))
>  
> -static const struct aspeed_sgpio_bank *to_bank(unsigned int offset)
> +static const struct aspeed_sgpio_bank *to_bank(unsigned int offset, 
> const struct aspeed_sgpio *gpio)

Bit of a nit-pick, but again here, the context pointer (const struct aspeed_sgpio *) should be the first argument.

>  {
>  	unsigned int bank;
>  
> -	bank = GPIO_BANK(offset);
> +	bank = GPIO_BANK(gpio, offset);
>  
>  	WARN_ON(bank >= ARRAY_SIZE(aspeed_sgpio_banks));
>  	return &aspeed_sgpio_banks[bank];
> @@ -139,18 +152,19 @@ 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 max_ngpios = sgpio->max_ngpios;
>  	int n = sgpio->n_sgpio;
> -	int c = SGPIO_OUTPUT_OFFSET - n;
> +	int c = max_ngpios - n;
>  
> -	WARN_ON(ngpios < MAX_NR_HW_SGPIO * 2);
> +	WARN_ON(ngpios < max_ngpios * 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);
> +	/* output GPIOS above max_ngpios */
> +	bitmap_set(valid_mask, max_ngpios, n);
> +	bitmap_clear(valid_mask, max_ngpios + n, c);
>  
>  	return 0;
>  }
> @@ -161,30 +175,30 @@ static void 
> aspeed_sgpio_irq_init_valid_mask(struct gpio_chip *gc,
>  	struct aspeed_sgpio *sgpio = gpiochip_get_data(gc);
>  	int n = sgpio->n_sgpio;
>  
> -	WARN_ON(ngpios < MAX_NR_HW_SGPIO * 2);
> +	WARN_ON(ngpios < sgpio->max_ngpios * 2);
>  
>  	/* input GPIOs in the lower range */
>  	bitmap_set(valid_mask, 0, n);
>  	bitmap_clear(valid_mask, n, ngpios - n);
>  }
>  
> -static bool aspeed_sgpio_is_input(unsigned int offset)
> +static bool aspeed_sgpio_is_input(unsigned int offset, const struct 
> aspeed_sgpio *gpio)
>  {
> -	return offset < SGPIO_OUTPUT_OFFSET;
> +	return offset < gpio->max_ngpios;
>  }
>  
>  static int aspeed_sgpio_get(struct gpio_chip *gc, unsigned int offset)
>  {
>  	struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
> -	const struct aspeed_sgpio_bank *bank = to_bank(offset);
> +	const struct aspeed_sgpio_bank *bank = to_bank(offset, gpio);
>  	unsigned long flags;
>  	enum aspeed_sgpio_reg reg;
>  	int rc = 0;
>  
>  	spin_lock_irqsave(&gpio->lock, flags);
>  
> -	reg = aspeed_sgpio_is_input(offset) ? reg_val : reg_rdata;
> -	rc = !!(ioread32(bank_reg(gpio, bank, reg)) & GPIO_BIT(offset));
> +	reg = aspeed_sgpio_is_input(offset, gpio) ? reg_val : reg_rdata;
> +	rc = !!(ioread32(bank_reg(gpio, bank, reg)) & GPIO_BIT(gpio, offset));
>  
>  	spin_unlock_irqrestore(&gpio->lock, flags);
>  
> @@ -194,11 +208,11 @@ static int aspeed_sgpio_get(struct gpio_chip *gc, 
> unsigned int offset)
>  static int sgpio_set_value(struct gpio_chip *gc, unsigned int offset, 
> int val)
>  {
>  	struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
> -	const struct aspeed_sgpio_bank *bank = to_bank(offset);
> +	const struct aspeed_sgpio_bank *bank = to_bank(offset, gpio);
>  	void __iomem *addr_r, *addr_w;
>  	u32 reg = 0;
>  
> -	if (aspeed_sgpio_is_input(offset))
> +	if (aspeed_sgpio_is_input(offset, gpio))
>  		return -EINVAL;
>  
>  	/* Since this is an output, read the cached value from rdata, then
> @@ -209,9 +223,9 @@ static int sgpio_set_value(struct gpio_chip *gc, 
> unsigned int offset, int val)
>  	reg = ioread32(addr_r);
>  
>  	if (val)
> -		reg |= GPIO_BIT(offset);
> +		reg |= GPIO_BIT(gpio, offset);
>  	else
> -		reg &= ~GPIO_BIT(offset);
> +		reg &= ~GPIO_BIT(gpio, offset);
>  
>  	iowrite32(reg, addr_w);
>  
> @@ -232,7 +246,9 @@ static void aspeed_sgpio_set(struct gpio_chip *gc, 
> unsigned int offset, int val)
>  
>  static int aspeed_sgpio_dir_in(struct gpio_chip *gc, unsigned int offset)
>  {
> -	return aspeed_sgpio_is_input(offset) ? 0 : -EINVAL;
> +	struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
> +
> +	return aspeed_sgpio_is_input(offset, gpio) ? 0 : -EINVAL;
>  }
>  
>  static int aspeed_sgpio_dir_out(struct gpio_chip *gc, unsigned int 
> offset, int val)
> @@ -253,7 +269,9 @@ static int aspeed_sgpio_dir_out(struct gpio_chip 
> *gc, unsigned int offset, int v
>  
>  static int aspeed_sgpio_get_direction(struct gpio_chip *gc, unsigned 
> int offset)
>  {
> -	return !!aspeed_sgpio_is_input(offset);
> +	struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
> +
> +	return !!aspeed_sgpio_is_input(offset, gpio);
>  }
>  
>  static void irqd_to_aspeed_sgpio_data(struct irq_data *d,
> @@ -268,8 +286,8 @@ static void irqd_to_aspeed_sgpio_data(struct irq_data *d,
>  	WARN_ON(!internal);
>  
>  	*gpio = internal;
> -	*bank = to_bank(*offset);
> -	*bit = GPIO_BIT(*offset);
> +	*bank = to_bank(*offset, internal);
> +	*bit = GPIO_BIT(internal, *offset);
>  }
>  
>  static void aspeed_sgpio_irq_ack(struct irq_data *d)
> @@ -466,9 +484,21 @@ static int aspeed_sgpio_setup_irqs(struct 
> aspeed_sgpio *gpio,
>  	return 0;
>  }
>  
> +static const struct aspeed_sgpio_pdata ast2600_sgpiom_128_pdata = {
> +	.max_ngpios = 128,
> +	.pin_mask = GENMASK(10, 6),
> +};
> +
> +static const struct aspeed_sgpio_pdata ast2600_sgpiom_80_pdata = {
> +	.max_ngpios = 80,
> +	.pin_mask = GENMASK(10, 6),
> +};
> +
>  static const struct of_device_id aspeed_sgpio_of_table[] = {
>  	{ .compatible = "aspeed,ast2400-sgpio" },
>  	{ .compatible = "aspeed,ast2500-sgpio" },

What happened to defining platform data for the 2400 and 2500 ...

> +	{ .compatible = "aspeed,ast2600-sgpiom-128", .data = 
> &ast2600_sgpiom_128_pdata, },
> +	{ .compatible = "aspeed,ast2600-sgpiom-80", .data = 
> &ast2600_sgpiom_80_pdata, },
>  	{}
>  };
>  
> @@ -476,10 +506,11 @@ 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)
> @@ -489,13 +520,22 @@ 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) {
> +		gpio->max_ngpios = pdata->max_ngpios;
> +		pin_mask = pdata->pin_mask;
> +	} else {
> +		gpio->max_ngpios = MAX_NR_HW_SGPIO;
> +		pin_mask = ASPEED_SGPIO_PINS_MASK;
> +	}
> +

... because we should avoid introducing this branch if possible.

Aside from these two minor issues, it looks okay to me.

Andrew

Patch

diff --git a/drivers/gpio/gpio-aspeed-sgpio.c b/drivers/gpio/gpio-aspeed-sgpio.c
index 64e54f8c30d2..ea20a0127748 100644
--- a/drivers/gpio/gpio-aspeed-sgpio.c
+++ b/drivers/gpio/gpio-aspeed-sgpio.c
@@ -34,6 +34,12 @@ 
 #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;
+	int max_ngpios;
+};
 
 struct aspeed_sgpio {
 	struct gpio_chip chip;
@@ -41,6 +47,7 @@  struct aspeed_sgpio {
 	spinlock_t lock;
 	void __iomem *base;
 	int irq;
+	int max_ngpios;
 	int n_sgpio;
 };
 
@@ -75,7 +82,13 @@  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" },
 	},
 };
 
@@ -121,15 +134,15 @@  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(gpio, x)    (((x) % (gpio)->max_ngpios) >> 5)
+#define GPIO_OFFSET(x)        ((x) & GENMASK(4, 0))
+#define GPIO_BIT(gpio, x)     BIT(GPIO_OFFSET((x) % (gpio)->max_ngpios))
 
-static const struct aspeed_sgpio_bank *to_bank(unsigned int offset)
+static const struct aspeed_sgpio_bank *to_bank(unsigned int offset, const struct aspeed_sgpio *gpio)
 {
 	unsigned int bank;
 
-	bank = GPIO_BANK(offset);
+	bank = GPIO_BANK(gpio, offset);
 
 	WARN_ON(bank >= ARRAY_SIZE(aspeed_sgpio_banks));
 	return &aspeed_sgpio_banks[bank];
@@ -139,18 +152,19 @@  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 max_ngpios = sgpio->max_ngpios;
 	int n = sgpio->n_sgpio;
-	int c = SGPIO_OUTPUT_OFFSET - n;
+	int c = max_ngpios - n;
 
-	WARN_ON(ngpios < MAX_NR_HW_SGPIO * 2);
+	WARN_ON(ngpios < max_ngpios * 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);
+	/* output GPIOS above max_ngpios */
+	bitmap_set(valid_mask, max_ngpios, n);
+	bitmap_clear(valid_mask, max_ngpios + n, c);
 
 	return 0;
 }
@@ -161,30 +175,30 @@  static void aspeed_sgpio_irq_init_valid_mask(struct gpio_chip *gc,
 	struct aspeed_sgpio *sgpio = gpiochip_get_data(gc);
 	int n = sgpio->n_sgpio;
 
-	WARN_ON(ngpios < MAX_NR_HW_SGPIO * 2);
+	WARN_ON(ngpios < sgpio->max_ngpios * 2);
 
 	/* input GPIOs in the lower range */
 	bitmap_set(valid_mask, 0, n);
 	bitmap_clear(valid_mask, n, ngpios - n);
 }
 
-static bool aspeed_sgpio_is_input(unsigned int offset)
+static bool aspeed_sgpio_is_input(unsigned int offset, const struct aspeed_sgpio *gpio)
 {
-	return offset < SGPIO_OUTPUT_OFFSET;
+	return offset < gpio->max_ngpios;
 }
 
 static int aspeed_sgpio_get(struct gpio_chip *gc, unsigned int offset)
 {
 	struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
-	const struct aspeed_sgpio_bank *bank = to_bank(offset);
+	const struct aspeed_sgpio_bank *bank = to_bank(offset, gpio);
 	unsigned long flags;
 	enum aspeed_sgpio_reg reg;
 	int rc = 0;
 
 	spin_lock_irqsave(&gpio->lock, flags);
 
-	reg = aspeed_sgpio_is_input(offset) ? reg_val : reg_rdata;
-	rc = !!(ioread32(bank_reg(gpio, bank, reg)) & GPIO_BIT(offset));
+	reg = aspeed_sgpio_is_input(offset, gpio) ? reg_val : reg_rdata;
+	rc = !!(ioread32(bank_reg(gpio, bank, reg)) & GPIO_BIT(gpio, offset));
 
 	spin_unlock_irqrestore(&gpio->lock, flags);
 
@@ -194,11 +208,11 @@  static int aspeed_sgpio_get(struct gpio_chip *gc, unsigned int offset)
 static int sgpio_set_value(struct gpio_chip *gc, unsigned int offset, int val)
 {
 	struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
-	const struct aspeed_sgpio_bank *bank = to_bank(offset);
+	const struct aspeed_sgpio_bank *bank = to_bank(offset, gpio);
 	void __iomem *addr_r, *addr_w;
 	u32 reg = 0;
 
-	if (aspeed_sgpio_is_input(offset))
+	if (aspeed_sgpio_is_input(offset, gpio))
 		return -EINVAL;
 
 	/* Since this is an output, read the cached value from rdata, then
@@ -209,9 +223,9 @@  static int sgpio_set_value(struct gpio_chip *gc, unsigned int offset, int val)
 	reg = ioread32(addr_r);
 
 	if (val)
-		reg |= GPIO_BIT(offset);
+		reg |= GPIO_BIT(gpio, offset);
 	else
-		reg &= ~GPIO_BIT(offset);
+		reg &= ~GPIO_BIT(gpio, offset);
 
 	iowrite32(reg, addr_w);
 
@@ -232,7 +246,9 @@  static void aspeed_sgpio_set(struct gpio_chip *gc, unsigned int offset, int val)
 
 static int aspeed_sgpio_dir_in(struct gpio_chip *gc, unsigned int offset)
 {
-	return aspeed_sgpio_is_input(offset) ? 0 : -EINVAL;
+	struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
+
+	return aspeed_sgpio_is_input(offset, gpio) ? 0 : -EINVAL;
 }
 
 static int aspeed_sgpio_dir_out(struct gpio_chip *gc, unsigned int offset, int val)
@@ -253,7 +269,9 @@  static int aspeed_sgpio_dir_out(struct gpio_chip *gc, unsigned int offset, int v
 
 static int aspeed_sgpio_get_direction(struct gpio_chip *gc, unsigned int offset)
 {
-	return !!aspeed_sgpio_is_input(offset);
+	struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
+
+	return !!aspeed_sgpio_is_input(offset, gpio);
 }
 
 static void irqd_to_aspeed_sgpio_data(struct irq_data *d,
@@ -268,8 +286,8 @@  static void irqd_to_aspeed_sgpio_data(struct irq_data *d,
 	WARN_ON(!internal);
 
 	*gpio = internal;
-	*bank = to_bank(*offset);
-	*bit = GPIO_BIT(*offset);
+	*bank = to_bank(*offset, internal);
+	*bit = GPIO_BIT(internal, *offset);
 }
 
 static void aspeed_sgpio_irq_ack(struct irq_data *d)
@@ -466,9 +484,21 @@  static int aspeed_sgpio_setup_irqs(struct aspeed_sgpio *gpio,
 	return 0;
 }
 
+static const struct aspeed_sgpio_pdata ast2600_sgpiom_128_pdata = {
+	.max_ngpios = 128,
+	.pin_mask = GENMASK(10, 6),
+};
+
+static const struct aspeed_sgpio_pdata ast2600_sgpiom_80_pdata = {
+	.max_ngpios = 80,
+	.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,ast2600-sgpiom-128", .data = &ast2600_sgpiom_128_pdata, },
+	{ .compatible = "aspeed,ast2600-sgpiom-80", .data = &ast2600_sgpiom_80_pdata, },
 	{}
 };
 
@@ -476,10 +506,11 @@  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)
@@ -489,13 +520,22 @@  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) {
+		gpio->max_ngpios = pdata->max_ngpios;
+		pin_mask = pdata->pin_mask;
+	} else {
+		gpio->max_ngpios = MAX_NR_HW_SGPIO;
+		pin_mask = ASPEED_SGPIO_PINS_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) {
+	} else if (nr_gpios > gpio->max_ngpios) {
 		dev_err(&pdev->dev, "Number of GPIOs exceeds the maximum of %d: %d\n",
-			MAX_NR_HW_SGPIO, nr_gpios);
+			gpio->max_ngpios, nr_gpios);
 		return -EINVAL;
 	}
 	gpio->n_sgpio = nr_gpios;
@@ -531,15 +571,14 @@  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 = gpio->max_ngpios * 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;