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, 2 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index a0e1b834af61..8325c44c04c6 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -496,6 +496,7 @@ config MFD_WM831X_I2C
         select MFD_CORE
         select MFD_WM831X
         select REGMAP_I2C
+        select IRQ_DOMAIN
         depends on I2C=y && GENERIC_HARDIRQS
         help
           Support for the Wolfson Microelecronics WM831x and WM832x PMICs
@@ -508,6 +509,7 @@ config MFD_WM831X_SPI
         select MFD_CORE
         select MFD_WM831X
         select REGMAP_SPI
+        select IRQ_DOMAIN
         depends on SPI_MASTER && GENERIC_HARDIRQS
         help
           Support for the Wolfson Microelecronics WM831x and WM832x PMICs