[PATCH V4 03/14] genirq: Generic chip: Allow irqchip drivers to override irq_reg_{readl,writel}

From: Kevin Cernekee
Date: Fri Nov 07 2014 - 01:48:14 EST


Currently, these I/O accessors always assume little endian 32-bit
registers (readl/writel). On some systems the IRQ registers need to be
accessed in BE mode or using 16-bit loads/stores, so we will provide a
way to override the default behavior.

Signed-off-by: Kevin Cernekee <cernekee@xxxxxxxxx>
---
include/linux/irq.h | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/include/linux/irq.h b/include/linux/irq.h
index ed1135d..0fecd95 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -686,6 +686,8 @@ struct irq_chip_type {
* struct irq_chip_generic - Generic irq chip data structure
* @lock: Lock to protect register and cache data access
* @reg_base: Register base address (virtual)
+ * @reg_readl: Alternate I/O accessor (defaults to readl if NULL)
+ * @reg_writel: Alternate I/O accessor (defaults to writel if NULL)
* @irq_base: Interrupt base nr for this chip
* @irq_cnt: Number of interrupts handled by this chip
* @mask_cache: Cached mask register shared between all chip types
@@ -710,6 +712,8 @@ struct irq_chip_type {
struct irq_chip_generic {
raw_spinlock_t lock;
void __iomem *reg_base;
+ u32 (*reg_readl)(void __iomem *addr);
+ void (*reg_writel)(u32 val, void __iomem *addr);
unsigned int irq_base;
unsigned int irq_cnt;
u32 mask_cache;
@@ -818,13 +822,19 @@ static inline void irq_gc_unlock(struct irq_chip_generic *gc) { }
static inline void irq_reg_writel(struct irq_chip_generic *gc,
u32 val, int reg_offset)
{
- writel(val, gc->reg_base + reg_offset);
+ if (gc->reg_writel)
+ gc->reg_writel(val, gc->reg_base + reg_offset);
+ else
+ writel(val, gc->reg_base + reg_offset);
}

static inline u32 irq_reg_readl(struct irq_chip_generic *gc,
int reg_offset)
{
- return readl(gc->reg_base + reg_offset);
+ if (gc->reg_readl)
+ return gc->reg_readl(gc->reg_base + reg_offset);
+ else
+ return readl(gc->reg_base + reg_offset);
}

#endif /* _LINUX_IRQ_H */
--
2.1.1

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