[PATCH v3 1/4] gpio: aspeed: Rework register type accessors

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

Use a single accessor function for all register types instead
of several spread around. This will make it easier/cleaner
to introduce new registers and keep the mechanism in one
place.

The big switch/case is optimized at compile time since the
switch value is a constant.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
---
 drivers/gpio/gpio-aspeed.c | 118 ++++++++++++++++++++++---------------
 1 file changed, 69 insertions(+), 49 deletions(-)

diff --git a/drivers/gpio/gpio-aspeed.c b/drivers/gpio/gpio-aspeed.c
index b31ae16170e7..c9baeeb7f0cc 100644
--- a/drivers/gpio/gpio-aspeed.c
+++ b/drivers/gpio/gpio-aspeed.c
@@ -127,12 +127,21 @@ static const struct aspeed_gpio_bank aspeed_gpio_banks[] = {
 	},
 };
 
-#define GPIO_BANK(x)	((x) >> 5)
-#define GPIO_OFFSET(x)	((x) & 0x1f)
-#define GPIO_BIT(x)	BIT(GPIO_OFFSET(x))
+enum aspeed_gpio_reg {
+	reg_val,
+	reg_dir,
+	reg_irq_enable,
+	reg_irq_type0,
+	reg_irq_type1,
+	reg_irq_type2,
+	reg_irq_status,
+	reg_debounce_sel1,
+	reg_debounce_sel2,
+	reg_tolerance,
+};
 
-#define GPIO_DATA	0x00
-#define GPIO_DIR	0x04
+#define GPIO_VAL_VALUE	0x00
+#define GPIO_VAL_DIR	0x04
 
 #define GPIO_IRQ_ENABLE	0x00
 #define GPIO_IRQ_TYPE0	0x04
@@ -143,6 +152,40 @@ static const struct aspeed_gpio_bank aspeed_gpio_banks[] = {
 #define GPIO_DEBOUNCE_SEL1 0x00
 #define GPIO_DEBOUNCE_SEL2 0x04
 
+/* This will be resolved at compile time */
+static inline void __iomem *bank_reg(struct aspeed_gpio *gpio,
+				     const struct aspeed_gpio_bank *bank,
+				     const enum aspeed_gpio_reg reg)
+{
+	switch (reg) {
+	case reg_val:
+		return gpio->base + bank->val_regs + GPIO_VAL_VALUE;
+	case reg_dir:
+		return gpio->base + bank->val_regs + GPIO_VAL_DIR;
+	case reg_irq_enable:
+		return gpio->base + bank->irq_regs + GPIO_IRQ_ENABLE;
+	case reg_irq_type0:
+		return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE0;
+	case reg_irq_type1:
+		return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE1;
+	case reg_irq_type2:
+		return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE2;
+	case reg_irq_status:
+		return gpio->base + bank->irq_regs + GPIO_IRQ_STATUS;
+	case reg_debounce_sel1:
+		return gpio->base + bank->debounce_regs + GPIO_DEBOUNCE_SEL1;
+	case reg_debounce_sel2:
+		return gpio->base + bank->debounce_regs + GPIO_DEBOUNCE_SEL2;
+	case reg_tolerance:
+		return gpio->base + bank->tolerance_regs;
+	}
+	BUG_ON(1);
+}
+
+#define GPIO_BANK(x)	((x) >> 5)
+#define GPIO_OFFSET(x)	((x) & 0x1f)
+#define GPIO_BIT(x)	BIT(GPIO_OFFSET(x))
+
 #define _GPIO_SET_DEBOUNCE(t, o, i) ((!!((t) & BIT(i))) << GPIO_OFFSET(o))
 #define GPIO_SET_DEBOUNCE1(t, o) _GPIO_SET_DEBOUNCE(t, o, 1)
 #define GPIO_SET_DEBOUNCE2(t, o) _GPIO_SET_DEBOUNCE(t, o, 0)
@@ -201,27 +244,12 @@ static inline bool have_output(struct aspeed_gpio *gpio, unsigned int offset)
 	return !props || (props->output & GPIO_BIT(offset));
 }
 
-static void __iomem *bank_val_reg(struct aspeed_gpio *gpio,
-		const struct aspeed_gpio_bank *bank,
-		unsigned int reg)
-{
-	return gpio->base + bank->val_regs + reg;
-}
-
-static void __iomem *bank_irq_reg(struct aspeed_gpio *gpio,
-		const struct aspeed_gpio_bank *bank,
-		unsigned int reg)
-{
-	return gpio->base + bank->irq_regs + reg;
-}
-
 static int aspeed_gpio_get(struct gpio_chip *gc, unsigned int offset)
 {
 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
 	const struct aspeed_gpio_bank *bank = to_bank(offset);
 
-	return !!(ioread32(bank_val_reg(gpio, bank, GPIO_DATA))
-			& GPIO_BIT(offset));
+	return !!(ioread32(bank_reg(gpio, bank, reg_val)) & GPIO_BIT(offset));
 }
 
 static void __aspeed_gpio_set(struct gpio_chip *gc, unsigned int offset,
@@ -232,7 +260,7 @@ static void __aspeed_gpio_set(struct gpio_chip *gc, unsigned int offset,
 	void __iomem *addr;
 	u32 reg;
 
-	addr = bank_val_reg(gpio, bank, GPIO_DATA);
+	addr = bank_reg(gpio, bank, reg_val);
 	reg = gpio->dcache[GPIO_BANK(offset)];
 
 	if (val)
@@ -269,8 +297,8 @@ static int aspeed_gpio_dir_in(struct gpio_chip *gc, unsigned int offset)
 
 	spin_lock_irqsave(&gpio->lock, flags);
 
-	reg = ioread32(bank_val_reg(gpio, bank, GPIO_DIR));
-	iowrite32(reg & ~GPIO_BIT(offset), bank_val_reg(gpio, bank, GPIO_DIR));
+	reg = ioread32(bank_reg(gpio, bank, reg_dir));
+	iowrite32(reg & ~GPIO_BIT(offset), bank_reg(gpio, bank, reg_dir));
 
 	spin_unlock_irqrestore(&gpio->lock, flags);
 
@@ -291,8 +319,8 @@ static int aspeed_gpio_dir_out(struct gpio_chip *gc,
 	spin_lock_irqsave(&gpio->lock, flags);
 
 	__aspeed_gpio_set(gc, offset, val);
-	reg = ioread32(bank_val_reg(gpio, bank, GPIO_DIR));
-	iowrite32(reg | GPIO_BIT(offset), bank_val_reg(gpio, bank, GPIO_DIR));
+	reg = ioread32(bank_reg(gpio, bank, reg_dir));
+	iowrite32(reg | GPIO_BIT(offset), bank_reg(gpio, bank, reg_dir));
 
 	spin_unlock_irqrestore(&gpio->lock, flags);
 
@@ -314,7 +342,7 @@ static int aspeed_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
 
 	spin_lock_irqsave(&gpio->lock, flags);
 
-	val = ioread32(bank_val_reg(gpio, bank, GPIO_DIR)) & GPIO_BIT(offset);
+	val = ioread32(bank_reg(gpio, bank, reg_dir)) & GPIO_BIT(offset);
 
 	spin_unlock_irqrestore(&gpio->lock, flags);
 
@@ -358,7 +386,7 @@ static void aspeed_gpio_irq_ack(struct irq_data *d)
 	if (rc)
 		return;
 
-	status_addr = bank_irq_reg(gpio, bank, GPIO_IRQ_STATUS);
+	status_addr = bank_reg(gpio, bank, reg_irq_status);
 
 	spin_lock_irqsave(&gpio->lock, flags);
 	iowrite32(bit, status_addr);
@@ -378,7 +406,7 @@ static void aspeed_gpio_irq_set_mask(struct irq_data *d, bool set)
 	if (rc)
 		return;
 
-	addr = bank_irq_reg(gpio, bank, GPIO_IRQ_ENABLE);
+	addr = bank_reg(gpio, bank, reg_irq_enable);
 
 	spin_lock_irqsave(&gpio->lock, flags);
 
@@ -442,17 +470,17 @@ static int aspeed_gpio_set_type(struct irq_data *d, unsigned int type)
 
 	spin_lock_irqsave(&gpio->lock, flags);
 
-	addr = bank_irq_reg(gpio, bank, GPIO_IRQ_TYPE0);
+	addr = bank_reg(gpio, bank, reg_irq_type0);
 	reg = ioread32(addr);
 	reg = (reg & ~bit) | type0;
 	iowrite32(reg, addr);
 
-	addr = bank_irq_reg(gpio, bank, GPIO_IRQ_TYPE1);
+	addr = bank_reg(gpio, bank, reg_irq_type1);
 	reg = ioread32(addr);
 	reg = (reg & ~bit) | type1;
 	iowrite32(reg, addr);
 
-	addr = bank_irq_reg(gpio, bank, GPIO_IRQ_TYPE2);
+	addr = bank_reg(gpio, bank, reg_irq_type2);
 	reg = ioread32(addr);
 	reg = (reg & ~bit) | type2;
 	iowrite32(reg, addr);
@@ -477,7 +505,7 @@ static void aspeed_gpio_irq_handler(struct irq_desc *desc)
 	for (i = 0; i < ARRAY_SIZE(aspeed_gpio_banks); i++) {
 		const struct aspeed_gpio_bank *bank = &aspeed_gpio_banks[i];
 
-		reg = ioread32(bank_irq_reg(data, bank, GPIO_IRQ_STATUS));
+		reg = ioread32(bank_reg(data, bank, reg_irq_status));
 
 		for_each_set_bit(p, &reg, 32) {
 			girq = irq_find_mapping(gc->irq.domain, i * 32 + p);
@@ -549,21 +577,21 @@ static int aspeed_gpio_reset_tolerance(struct gpio_chip *chip,
 					unsigned int offset, bool enable)
 {
 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
-	const struct aspeed_gpio_bank *bank;
 	unsigned long flags;
+	void __iomem *treg;
 	u32 val;
 
-	bank = to_bank(offset);
+	treg = bank_reg(gpio, to_bank(offset), reg_tolerance);
 
 	spin_lock_irqsave(&gpio->lock, flags);
-	val = readl(gpio->base + bank->tolerance_regs);
+	val = readl(treg);
 
 	if (enable)
 		val |= GPIO_BIT(offset);
 	else
 		val &= ~GPIO_BIT(offset);
 
-	writel(val, gpio->base + bank->tolerance_regs);
+	writel(val, treg);
 	spin_unlock_irqrestore(&gpio->lock, flags);
 
 	return 0;
@@ -582,13 +610,6 @@ static void aspeed_gpio_free(struct gpio_chip *chip, unsigned int offset)
 	pinctrl_gpio_free(chip->base + offset);
 }
 
-static inline void __iomem *bank_debounce_reg(struct aspeed_gpio *gpio,
-		const struct aspeed_gpio_bank *bank,
-		unsigned int reg)
-{
-	return gpio->base + bank->debounce_regs + reg;
-}
-
 static int usecs_to_cycles(struct aspeed_gpio *gpio, unsigned long usecs,
 		u32 *cycles)
 {
@@ -666,11 +687,11 @@ static void configure_timer(struct aspeed_gpio *gpio, unsigned int offset,
 	void __iomem *addr;
 	u32 val;
 
-	addr = bank_debounce_reg(gpio, bank, GPIO_DEBOUNCE_SEL1);
+	addr = bank_reg(gpio, bank, reg_debounce_sel1);
 	val = ioread32(addr);
 	iowrite32((val & ~mask) | GPIO_SET_DEBOUNCE1(timer, offset), addr);
 
-	addr = bank_debounce_reg(gpio, bank, GPIO_DEBOUNCE_SEL2);
+	addr = bank_reg(gpio, bank, reg_debounce_sel2);
 	val = ioread32(addr);
 	iowrite32((val & ~mask) | GPIO_SET_DEBOUNCE2(timer, offset), addr);
 }
@@ -904,9 +925,8 @@ static int __init aspeed_gpio_probe(struct platform_device *pdev)
 
 	/* Populate it with initial values read from the HW */
 	for (i = 0; i < banks; i++) {
-		const struct aspeed_gpio_bank *bank = &aspeed_gpio_banks[i];
-		gpio->dcache[i] = ioread32(gpio->base + bank->val_regs +
-					   GPIO_DATA);
+		void __iomem *addr = bank_reg(gpio, &aspeed_gpio_banks[i], reg_val);
+		gpio->dcache[i] = ioread32(addr);
 	}
 
 	rc = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
-- 
2.17.1