1 files changed, 15 insertions, 7 deletions

diff --git a/drivers/gpio/max730x.c b/drivers/gpio/max730x.c
index 7696a5625d58..94ce773f95f8 100644
--- a/drivers/gpio/max730x.c
+++ b/drivers/gpio/max730x.c
@@ -54,7 +54,7 @@ static int max7301_direction_input(struct gpio_chip *chip, unsigned offset)
 {
         struct max7301 *ts = container_of(chip, struct max7301, chip);
         u8 *config;
-        u8 offset_bits;
+        u8 offset_bits, pin_config;
         int ret;
 
         /* First 4 pins are unused in the controller */
@@ -63,12 +63,15 @@ static int max7301_direction_input(struct gpio_chip *chip, unsigned offset)
 
         config = &ts->port_config[offset >> 2];
 
+        if (ts->input_pullup_active & BIT(offset))
+                pin_config = PIN_CONFIG_IN_PULLUP;
+        else
+                pin_config = PIN_CONFIG_IN_WO_PULLUP;
+
         mutex_lock(&ts->lock);
 
-        /* Standard GPIO API doesn't support pull-ups, has to be extended.
-         * Hard-coding no pollup for now. */
         *config = (*config & ~(PIN_CONFIG_MASK << offset_bits))
-                           | (PIN_CONFIG_IN_WO_PULLUP << offset_bits);
+                           | (pin_config << offset_bits);
 
         ret = ts->write(ts->dev, 0x08 + (offset >> 2), *config);
 
@@ -177,6 +180,7 @@ int __devinit __max730x_probe(struct max7301 *ts)
         /* Power up the chip and disable IRQ output */
         ts->write(dev, 0x04, 0x01);
 
+        ts->input_pullup_active = pdata->input_pullup_active;
         ts->chip.label = dev->driver->name;
 
         ts->chip.direction_input = max7301_direction_input;
@@ -191,13 +195,17 @@ int __devinit __max730x_probe(struct max7301 *ts)
         ts->chip.owner = THIS_MODULE;
 
         /*
-         * tristate all pins in hardware and cache the
+         * initialize pullups according to platform data and cache the
          * register values for later use.
          */
         for (i = 1; i < 8; i++) {
                 int j;
-                /* 0xAA means input with internal pullup disabled */
-                ts->write(dev, 0x08 + i, 0xAA);
+                /*
+                 * initialize port_config with "0xAA", which means
+                 * input with internal pullup disabled. This is needed
+                 * to avoid writing zeros (in the inner for loop),
+                 * which is not allowed according to the datasheet.
+                 */
                 ts->port_config[i] = 0xAA;
                 for (j = 0; j < 4; j++) {
                         int offset = (i - 1) * 4 + j;