irqchip/irq-mtk-cirq: Move register offsets to const array

In preparation to add support for new SoCs having a different
register layout, add an enumeration that documents register
offsets and move the definitions for the same to a u32 array;

Selecting the right register offsets array is done by adding an
of_device_id array containing all of the currently supported
compatible strings pointing to the "v1" offsets array (as data):
since no devicetree declares the `mediatek,mtk-cirq` compatible
without a SoC-specific one, it wasn't necessary to provide any
legacy fallback.

Every usage of the aforemementioned definitions was changed to
get a register address through a newly introduced `mtk_cirq_reg()`
accessor.

This change brings no functional changes.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221128092217.36552-4-angelogioacchino.delregno@collabora.com

Author: AngeloGioacchino Del Regno

drivers/irqchip/irq-mtk-cirq.c

@@ -15,14 +15,29 @@
 #include <linux/slab.h>
 #include <linux/syscore_ops.h>
 
-#define CIRQ_ACK	0x40
-#define CIRQ_MASK_SET	0xc0
-#define CIRQ_MASK_CLR	0x100
-#define CIRQ_SENS_SET	0x180
-#define CIRQ_SENS_CLR	0x1c0
-#define CIRQ_POL_SET	0x240
-#define CIRQ_POL_CLR	0x280
-#define CIRQ_CONTROL	0x300
+enum mtk_cirq_regoffs_index {
+	CIRQ_STA,
+	CIRQ_ACK,
+	CIRQ_MASK_SET,
+	CIRQ_MASK_CLR,
+	CIRQ_SENS_SET,
+	CIRQ_SENS_CLR,
+	CIRQ_POL_SET,
+	CIRQ_POL_CLR,
+	CIRQ_CONTROL
+};
+
+static const u32 mtk_cirq_regoffs_v1[] = {
+	[CIRQ_STA]	= 0x0,
+	[CIRQ_ACK]	= 0x40,
+	[CIRQ_MASK_SET]	= 0xc0,
+	[CIRQ_MASK_CLR]	= 0x100,
+	[CIRQ_SENS_SET]	= 0x180,
+	[CIRQ_SENS_CLR]	= 0x1c0,
+	[CIRQ_POL_SET]	= 0x240,
+	[CIRQ_POL_CLR]	= 0x280,
+	[CIRQ_CONTROL]	= 0x300,
+};
 
 #define CIRQ_EN	0x1
 #define CIRQ_EDGE	0x2
@@ -32,18 +47,32 @@ struct mtk_cirq_chip_data {
 	void __iomem *base;
 	unsigned int ext_irq_start;
 	unsigned int ext_irq_end;
+	const u32 *offsets;
 	struct irq_domain *domain;
 };
 
 static struct mtk_cirq_chip_data *cirq_data;
 
-static void mtk_cirq_write_mask(struct irq_data *data, unsigned int offset)
+static void __iomem *mtk_cirq_reg(struct mtk_cirq_chip_data *chip_data,
+				  enum mtk_cirq_regoffs_index idx)
+{
+	return chip_data->base + chip_data->offsets[idx];
+}
+
+static void __iomem *mtk_cirq_irq_reg(struct mtk_cirq_chip_data *chip_data,
+				      enum mtk_cirq_regoffs_index idx,
+				      unsigned int cirq_num)
+{
+	return mtk_cirq_reg(chip_data, idx) + (cirq_num / 32) * 4;
+}
+
+static void mtk_cirq_write_mask(struct irq_data *data, enum mtk_cirq_regoffs_index idx)
 {
 	struct mtk_cirq_chip_data *chip_data = data->chip_data;
 	unsigned int cirq_num = data->hwirq;
 	u32 mask = 1 << (cirq_num % 32);
 
-	writel_relaxed(mask, chip_data->base + offset + (cirq_num / 32) * 4);
+	writel_relaxed(mask, mtk_cirq_irq_reg(chip_data, idx, cirq_num));
 }
 
 static void mtk_cirq_mask(struct irq_data *data)
@@ -160,6 +189,7 @@ static const struct irq_domain_ops cirq_domain_ops = {
 #ifdef CONFIG_PM_SLEEP
 static int mtk_cirq_suspend(void)
 {
+	void __iomem *reg;
 	u32 value, mask;
 	unsigned int irq, hwirq_num;
 	bool pending, masked;
@@ -200,31 +230,34 @@ static int mtk_cirq_suspend(void)
 				continue;
 		}
 
+		reg = mtk_cirq_irq_reg(cirq_data, CIRQ_ACK, i);
 		mask = 1 << (i % 32);
-		writel_relaxed(mask, cirq_data->base + CIRQ_ACK + (i / 32) * 4);
+		writel_relaxed(mask, reg);
 	}
 
 	/* set edge_only mode, record edge-triggerd interrupts */
 	/* enable cirq */
-	value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
+	reg = mtk_cirq_reg(cirq_data, CIRQ_CONTROL);
+	value = readl_relaxed(reg);
 	value |= (CIRQ_EDGE | CIRQ_EN);
-	writel_relaxed(value, cirq_data->base + CIRQ_CONTROL);
+	writel_relaxed(value, reg);
 
 	return 0;
 }
 
 static void mtk_cirq_resume(void)
 {
+	void __iomem *reg = mtk_cirq_reg(cirq_data, CIRQ_CONTROL);
 	u32 value;
 
 	/* flush recorded interrupts, will send signals to parent controller */
-	value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
-	writel_relaxed(value | CIRQ_FLUSH, cirq_data->base + CIRQ_CONTROL);
+	value = readl_relaxed(reg);
+	writel_relaxed(value | CIRQ_FLUSH, reg);
 
 	/* disable cirq */
-	value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
+	value = readl_relaxed(reg);
 	value &= ~(CIRQ_EDGE | CIRQ_EN);
-	writel_relaxed(value, cirq_data->base + CIRQ_CONTROL);
+	writel_relaxed(value, reg);
 }
 
 static struct syscore_ops mtk_cirq_syscore_ops = {
@@ -240,10 +273,18 @@ static void mtk_cirq_syscore_init(void)
 static inline void mtk_cirq_syscore_init(void) {}
 #endif
 
+static const struct of_device_id mtk_cirq_of_match[] = {
+	{ .compatible = "mediatek,mt2701-cirq", .data = &mtk_cirq_regoffs_v1 },
+	{ .compatible = "mediatek,mt8135-cirq", .data = &mtk_cirq_regoffs_v1 },
+	{ .compatible = "mediatek,mt8173-cirq", .data = &mtk_cirq_regoffs_v1 },
+	{ /* sentinel */ }
+};
+
 static int __init mtk_cirq_of_init(struct device_node *node,
 				   struct device_node *parent)
 {
 	struct irq_domain *domain, *domain_parent;
+	const struct of_device_id *match;
 	unsigned int irq_num;
 	int ret;
 
@@ -274,6 +315,13 @@ static int __init mtk_cirq_of_init(struct device_node *node,
 	if (ret)
 		goto out_unmap;
 
+	match = of_match_node(mtk_cirq_of_match, node);
+	if (!match) {
+		ret = -ENODEV;
+		goto out_unmap;
+	}
+	cirq_data->offsets = match->data;
+
 	irq_num = cirq_data->ext_irq_end - cirq_data->ext_irq_start + 1;
 	domain = irq_domain_add_hierarchy(domain_parent, 0,
 					  irq_num, node,