ARM: s3c24xx: spi: avoid hardcoding fiq number in driver

The IRQ_EINT0 constant is a platform detail that is
defined in mach/irqs.h and not visible to drivers once
that header is made private.

Since the same calculation already happens in s3c24xx_set_fiq,
just return the value from there.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200806182059.2431-31-krzk@kernel.orgSigned-off-by: Krzysztof Kozlowski <krzk@kernel.org>

arch/arm/mach-s3c24xx/irq-s3c24xx.c

@@ -376,14 +376,17 @@ asmlinkage void __exception_irq_entry s3c24xx_handle_irq(struct pt_regs *regs)
 /**
  * s3c24xx_set_fiq - set the FIQ routing
  * @irq: IRQ number to route to FIQ on processor.
+ * @ack_ptr: pointer to a location for storing the bit mask
  * @on: Whether to route @irq to the FIQ, or to remove the FIQ routing.
  *
  * Change the state of the IRQ to FIQ routing depending on @irq and @on. If
  * @on is true, the @irq is checked to see if it can be routed and the
  * interrupt controller updated to route the IRQ. If @on is false, the FIQ
  * routing is cleared, regardless of which @irq is specified.
+ *
+ * returns the mask value for the register.
  */
-int s3c24xx_set_fiq(unsigned int irq, bool on)
+int s3c24xx_set_fiq(unsigned int irq, u32 *ack_ptr, bool on)
 {
 	u32 intmod;
 	unsigned offs;
@@ -391,15 +394,18 @@ int s3c24xx_set_fiq(unsigned int irq, bool on)
 	if (on) {
 		offs = irq - FIQ_START;
 		if (offs > 31)
-			return -EINVAL;
+			return 0;
 
 		intmod = 1 << offs;
 	} else {
 		intmod = 0;
 	}
 
+	if (ack_ptr)
+		*ack_ptr = intmod;
 	writel_relaxed(intmod, S3C2410_INTMOD);
-	return 0;
+
+	return intmod;
 }
 
 EXPORT_SYMBOL_GPL(s3c24xx_set_fiq);

drivers/spi/spi-s3c24xx.c

@@ -229,17 +229,6 @@ struct spi_fiq_code {
 	u8	data[];
 };
 
-/**
- * ack_bit - turn IRQ into IRQ acknowledgement bit
- * @irq: The interrupt number
- *
- * Returns the bit to write to the interrupt acknowledge register.
- */
-static inline u32 ack_bit(unsigned int irq)
-{
-	return 1 << (irq - IRQ_EINT0);
-}
-
 /**
  * s3c24xx_spi_tryfiq - attempt to claim and setup FIQ for transfer
  * @hw: The hardware state.
@@ -256,6 +245,7 @@ static void s3c24xx_spi_tryfiq(struct s3c24xx_spi *hw)
 	struct pt_regs regs;
 	enum spi_fiq_mode mode;
 	struct spi_fiq_code *code;
+	u32 *ack_ptr = NULL;
 	int ret;
 
 	if (!hw->fiq_claimed) {
@@ -282,8 +272,6 @@ static void s3c24xx_spi_tryfiq(struct s3c24xx_spi *hw)
 	set_fiq_regs(&regs);
 
 	if (hw->fiq_mode != mode) {
-		u32 *ack_ptr;
-
 		hw->fiq_mode = mode;
 
 		switch (mode) {
@@ -303,12 +291,10 @@ static void s3c24xx_spi_tryfiq(struct s3c24xx_spi *hw)
 		BUG_ON(!code);
 
 		ack_ptr = (u32 *)&code->data[code->ack_offset];
-		*ack_ptr = ack_bit(hw->irq);
-
 		set_fiq_handler(&code->data, code->length);
 	}
 
-	s3c24xx_set_fiq(hw->irq, true);
+	s3c24xx_set_fiq(hw->irq, ack_ptr, true);
 
 	hw->fiq_mode = mode;
 	hw->fiq_inuse = 1;

include/linux/spi/s3c24xx.h

@@ -20,6 +20,6 @@ struct s3c2410_spi_info {
 	void (*set_cs)(struct s3c2410_spi_info *spi, int cs, int pol);
 };
 
-extern int s3c24xx_set_fiq(unsigned int irq, bool on);
+extern int s3c24xx_set_fiq(unsigned int irq, u32 *ack_ptr, bool on);
 
 #endif /* __LINUX_SPI_S3C24XX_H */