gpio: max730x: make pullups configurable via platformdata

The gpios on the max730x chips have support for internal pullups while in
input mode.

This patch adds support for configuring these pullups via platform data.
A new member ("input_pullup_active") to the platform data struct is
introduced.  A set bit in this variable activates the pullups while the
respective port is in input mode.  This is a compatible enhancement since
unset bits lead to disables pullups which was the default in the original
driver.

_Note_: the 4 lowest bits in "input_pullup_active" are unused because the
first 4 ports of the controller are not used, too.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/linux/spi/max7301.h b/include/linux/spi/max7301.h
index 34af0a3477bf..bcaa2f762cc1 100644
--- a/include/linux/spi/max7301.h
+++ b/include/linux/spi/max7301.h
@@ -11,6 +11,7 @@ struct max7301 {
         struct mutex    lock;
         u8              port_config[8]; /* field 0 is unused */
         u32             out_level;      /* cached output levels */
+        u32             input_pullup_active;
         struct gpio_chip chip;
         struct device *dev;
         int (*write)(struct device *dev, unsigned int reg, unsigned int val);
@@ -20,6 +21,13 @@ struct max7301 {
 struct max7301_platform_data {
         /* number assigned to the first GPIO */
         unsigned        base;
+        /*
+         * bitmask controlling the pullup configuration,
+         *
+         * _note_ the 4 lowest bits are unused, because the first 4
+         * ports of the controller are not used, too.
+         */
+        u32             input_pullup_active;
 };
 
 extern int __max730x_remove(struct device *dev);