mfd: Convert wm831x to irq_domain

The modern idiom is to use irq_domain to allocate interrupts. This is
useful partly to allow further infrastructure to be based on the domains
and partly because it makes it much easier to allocate virtual interrupts
to devices as we don't need to allocate a contiguous range of interrupt
numbers.

Convert the wm831x driver over to this infrastructure, using a legacy
IRQ mapping if an irq_base is specified in platform data and otherwise
using a linear mapping, always registering the interrupts even if they
won't ever be used. Only boards which need to use the GPIOs as
interrupts should need to use an irq_base.

This means that we can't use the MFD irq_base management since the
unless we're using an explicit irq_base from platform data we can't rely
on a linear mapping of interrupts.  Instead we need to map things via
the irq_domain - provide a conveniencem function wm831x_irq() to save a
small amount of typing when doing so. Looking at this I couldn't clearly
see anything the MFD core could do to make this nicer.

Since we're not supporting device tree yet there's no meaningful
advantage if we don't do this conversion in one, the fact that the
interrupt resources are used for repeated IP blocks makes accessor
functions for the irq_domain more trouble to do than they're worth.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/include/linux/mfd/wm831x/core.h b/include/linux/mfd/wm831x/core.h
index 4b1211859f7..736191cc7e0 100644
--- a/include/linux/mfd/wm831x/core.h
+++ b/include/linux/mfd/wm831x/core.h
@@ -17,6 +17,7 @@
 
 #include <linux/completion.h>
 #include <linux/interrupt.h>
+#include <linux/irqdomain.h>
 #include <linux/list.h>
 #include <linux/regmap.h>
 
@@ -338,6 +339,7 @@
 #define WM831X_FLL_CLK_SRC_WIDTH                     2  /* FLL_CLK_SRC - [1:0] */
 
 struct regulator_dev;
+struct irq_domain;
 
 #define WM831X_NUM_IRQ_REGS 5
 #define WM831X_NUM_GPIO_REGS 16
@@ -367,7 +369,7 @@ struct wm831x {
 
 	int irq;  /* Our chip IRQ */
 	struct mutex irq_lock;
-	int irq_base;
+	struct irq_domain *irq_domain;
 	int irq_masks_cur[WM831X_NUM_IRQ_REGS];   /* Currently active value */
 	int irq_masks_cache[WM831X_NUM_IRQ_REGS]; /* Cached hardware value */
 
@@ -417,6 +419,11 @@ int wm831x_irq_init(struct wm831x *wm831x, int irq);
 void wm831x_irq_exit(struct wm831x *wm831x);
 void wm831x_auxadc_init(struct wm831x *wm831x);
 
+static inline int wm831x_irq(struct wm831x *wm831x, int irq)
+{
+	return irq_create_mapping(wm831x->irq_domain, irq);
+}
+
 extern struct regmap_config wm831x_regmap_config;
 
 #endif