irqchip/meson-gpio: Add support for meson a1 SoCs

The meson a1 Socs have some changes compared with previous
chips. For A113L, it contains 62 pins and can be spied on:

- 62:128 undefined
- 61:50 12 pins on bank A
- 49:37 13 pins on bank F
- 36:20 17 pins on bank X
- 19:13 7  pins on bank B
- 12:0  13 pins on bank P

There are five relative registers for gpio interrupt controller,
details are as below:

- PADCTRL_GPIO_IRQ_CTRL0
  bit[31]:    enable/disable the whole irq lines
  bit[16-23]: both edge trigger
  bit[8-15]:  single edge trigger
  bit[0-7]:   pol trigger

- PADCTRL_GPIO_IRQ_CTRL[X]
  bit[0-6]:   7 bits to choose gpio source for irq line 2*[X] - 2
  bit[16-22]: 7 bits to choose gpio source for irq line 2*[X] - 1
  where X =1,2,3,4
Signed-off-by: Qianggui Song <qianggui.song@amlogic.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20191216123645.10099-4-qianggui.song@amlogic.com

drivers/irqchip/irq-meson-gpio.c

@@ -24,6 +24,9 @@
 #define REG_PIN_47_SEL	0x08
 #define REG_FILTER_SEL	0x0c
 
+/* use for A1 like chips */
+#define REG_PIN_A1_SEL	0x04
+
 /*
  * Note: The S905X3 datasheet reports that BOTH_EDGE is controlled by
  * bits 24 to 31. Tests on the actual HW show that these bits are
@@ -44,6 +47,10 @@ struct meson_gpio_irq_controller;
 static void meson8_gpio_irq_sel_pin(struct meson_gpio_irq_controller *ctl,
 				    unsigned int channel, unsigned long hwirq);
 static void meson_gpio_irq_init_dummy(struct meson_gpio_irq_controller *ctl);
+static void meson_a1_gpio_irq_sel_pin(struct meson_gpio_irq_controller *ctl,
+				      unsigned int channel,
+				      unsigned long hwirq);
+static void meson_a1_gpio_irq_init(struct meson_gpio_irq_controller *ctl);
 
 struct irq_ctl_ops {
 	void (*gpio_irq_sel_pin)(struct meson_gpio_irq_controller *ctl,
@@ -75,6 +82,15 @@ struct meson_gpio_irq_params {
 	.pol_low_offset = 16,					\
 	.pin_sel_mask = 0xff,					\
 
+#define INIT_MESON_A1_COMMON_DATA(irqs)				\
+	INIT_MESON_COMMON(irqs, meson_a1_gpio_irq_init,		\
+			  meson_a1_gpio_irq_sel_pin)		\
+	.support_edge_both = true,				\
+	.edge_both_offset = 16,					\
+	.edge_single_offset = 8,				\
+	.pol_low_offset = 0,					\
+	.pin_sel_mask = 0x7f,					\
+
 static const struct meson_gpio_irq_params meson8_params = {
 	INIT_MESON8_COMMON_DATA(134)
 };
@@ -101,6 +117,10 @@ static const struct meson_gpio_irq_params sm1_params = {
 	.edge_both_offset = 8,
 };
 
+static const struct meson_gpio_irq_params a1_params = {
+	INIT_MESON_A1_COMMON_DATA(62)
+};
+
 static const struct of_device_id meson_irq_gpio_matches[] = {
 	{ .compatible = "amlogic,meson8-gpio-intc", .data = &meson8_params },
 	{ .compatible = "amlogic,meson8b-gpio-intc", .data = &meson8b_params },
@@ -109,6 +129,7 @@ static const struct of_device_id meson_irq_gpio_matches[] = {
 	{ .compatible = "amlogic,meson-axg-gpio-intc", .data = &axg_params },
 	{ .compatible = "amlogic,meson-g12a-gpio-intc", .data = &axg_params },
 	{ .compatible = "amlogic,meson-sm1-gpio-intc", .data = &sm1_params },
+	{ .compatible = "amlogic,meson-a1-gpio-intc", .data = &a1_params },
 	{ }
 };
 
@@ -149,6 +170,27 @@ static void meson8_gpio_irq_sel_pin(struct meson_gpio_irq_controller *ctl,
 				   hwirq << bit_offset);
 }
 
+static void meson_a1_gpio_irq_sel_pin(struct meson_gpio_irq_controller *ctl,
+				      unsigned int channel,
+				      unsigned long hwirq)
+{
+	unsigned int reg_offset;
+	unsigned int bit_offset;
+
+	bit_offset = ((channel % 2) == 0) ? 0 : 16;
+	reg_offset = REG_PIN_A1_SEL + ((channel / 2) << 2);
+
+	meson_gpio_irq_update_bits(ctl, reg_offset,
+				   ctl->params->pin_sel_mask << bit_offset,
+				   hwirq << bit_offset);
+}
+
+/* For a1 or later chips like a1 there is a switch to enable/disable irq */
+static void meson_a1_gpio_irq_init(struct meson_gpio_irq_controller *ctl)
+{
+	meson_gpio_irq_update_bits(ctl, REG_EDGE_POL, BIT(31), BIT(31));
+}
+
 static int
 meson_gpio_irq_request_channel(struct meson_gpio_irq_controller *ctl,
 			       unsigned long  hwirq,