Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt...

[firefly-linux-kernel-4.4.55.git] / drivers / gpio / max730x.c

diff --git a/drivers/gpio/max730x.c b/drivers/gpio/max730x.c
index 7696a5625d58c1944d8e15a72cf0f4768ff3f550..94ce773f95f8eebb7a54e09c7c6e2bb00b58128f 100644 (file)
--- 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;