gpio: mcp23s08 to support both device tree and platform data

Device tree is not enabled in some architecture where gpio
driver mcp23s08 is still required.

v2-changes:
- Parse device tree properties into platform data other than
  individual variables.
v3-changes:
- Use of_node in gpio_chip device structure, because the
  struct device * always has an of_node which is NULL when
  OF is not used.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 18 insertions, 0 deletions

diff --git a/include/linux/spi/mcp23s08.h b/include/linux/spi/mcp23s08.h
index 2d676d5aaa89..aa07d7b32568 100644
--- a/include/linux/spi/mcp23s08.h
+++ b/include/linux/spi/mcp23s08.h
@@ -22,4 +22,22 @@ struct mcp23s08_platform_data {
          * base to base+15 (or base+31 for s17 variant).
          */
         unsigned        base;
+        /* Marks the device as a interrupt controller.
+         * NOTE: The interrupt functionality is only supported for i2c
+         * versions of the chips. The spi chips can also do the interrupts,
+         * but this is not supported by the linux driver yet.
+         */
+        bool            irq_controller;
+
+        /* Sets the mirror flag in the IOCON register. Devices
+         * with two interrupt outputs (these are the devices ending with 17 and
+         * those that have 16 IOs) have two IO banks: IO 0-7 form bank 1 and
+         * IO 8-15 are bank 2. These chips have two different interrupt outputs:
+         * One for bank 1 and another for bank 2. If irq-mirror is set, both
+         * interrupts are generated regardless of the bank that an input change
+         * occurred on. If it is not set, the interrupt are only generated for
+         * the bank they belong to.
+         * On devices with only one interrupt output this property is useless.
+         */
+        bool            mirror;
 };