AOSCOS: gpio: loongson-64bit: Add LS7A GPIO interrupt support

On IPASON NL38-N11 laptops, the touchpad device (a HID multitouch device
connected via I2C) uses GPIO 50 to send interrupts. Unfortunately,
gpio-loongson-64bit does not support interrupt for LS7A yet, causing the
touchpad fail to be probed with:

    i2c_hid_acpi i2c-PNP0C50:00: HID over i2c has not been provided an Int IRQ

Add the offset of the GPIO_INT_EN controlling register to
loongson_gpio_ls7a_data to support the interrupt.

And, in LS7A the GPIO 4 ... 56 share the same interrupt pin, we need to
take this fact into account when calling platform_get_irq or we'd fail
with "IRQ index 50 not found."

Signed-off-by: Xi Ruoyao <[email protected]>

Author: xry111

drivers/gpio/gpio-loongson-64bit.c

@@ -27,6 +27,7 @@ struct loongson_gpio_chip_data {
 	unsigned int		out_offset;
 	unsigned int		in_offset;
 	unsigned int		inten_offset;
+	bool			is_ls7a;
 };
 
 struct loongson_gpio_chip {
@@ -132,6 +133,9 @@ static int loongson_gpio_to_irq(struct gpio_chip *chip, unsigned int offset)
 		writeb(1, lgpio->reg_base + lgpio->chip_data->inten_offset + offset);
 	}
 
+	if (lgpio->chip_data->is_ls7a)
+		offset = MIN(offset, 4);
+
 	return platform_get_irq(pdev, offset);
 }
 
@@ -258,6 +262,7 @@ static const struct loongson_gpio_chip_data loongson_gpio_ls7a_data = {
 	.in_offset = 0xa00,
 	.out_offset = 0x900,
 	.inten_offset = 0xb00,
+	.is_ls7a = true,
 };
 
 /* LS7A2000 chipset GPIO */