[PATCH RFC 2/2] gpio-max730x: Add block GPIO API

[Roland Stigge <stigge@antcom.de>]

This patch adds block GPIO API support to the MAX730x driver.

Due to hardware constraints in this chip, simultaneous access to GPIO lines can
only be done in groups of 8: GPIOs 0-7, 8-15, 16-23, 24-27. However, setting
and clearing will be done at once.

Signed-off-by: Roland Stigge <stigge@antcom.de>

---
 drivers/gpio/gpio-max730x.c |   53 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

--- linux-2.6.orig/drivers/gpio/gpio-max730x.c
+++ linux-2.6/drivers/gpio/gpio-max730x.c
@@ -146,6 +146,37 @@ static int max7301_get(struct gpio_chip
 	return level;
 }
 
+static void max7301_get_block(struct gpio_chip *chip, u8 *values, size_t size)
+{
+	struct max7301 *ts = container_of(chip, struct max7301, chip);
+	int i, j;
+
+	for (i = 0; i < size; i++) {
+		u8 in_level = ts->read(ts->dev, 0x44 + i * 8);
+		u8 in_mask = 0;
+		u8 out_level = (ts->out_level >> (i * 8 + 4)) & 0xFF;
+		u8 out_mask = 0;
+
+		for (j = 0; j < 8; j++) {
+			int offset = 4 + i * 8 + j;
+			int config = (ts->port_config[offset >> 2] >>
+				      ((offset & 3) << 1)) &
+				     PIN_CONFIG_MASK;
+
+			switch (config) {
+			case PIN_CONFIG_OUT:
+				out_mask |= BIT(j);
+				break;
+			case PIN_CONFIG_IN_WO_PULLUP:
+			case PIN_CONFIG_IN_PULLUP:
+				in_mask |= BIT(j);
+			}
+		}
+
+		values[i] = (in_level & in_mask) | (out_level & out_mask);
+	}
+}
+
 static void max7301_set(struct gpio_chip *chip, unsigned offset, int value)
 {
 	struct max7301 *ts = container_of(chip, struct max7301, chip);
@@ -160,6 +191,26 @@ static void max7301_set(struct gpio_chip
 	mutex_unlock(&ts->lock);
 }
 
+static
+void max7301_set_block(struct gpio_chip *chip, u8 *set, u8 *clr, size_t size)
+{
+	struct max7301 *ts = container_of(chip, struct max7301, chip);
+	int i;
+
+	mutex_lock(&ts->lock);
+
+	for (i = 0; i < size; i++) {
+		if (set[i] | clr[i]) { /* only on change */
+			ts->out_level |= (u32)set[i] << (i * 8 + 4);
+			ts->out_level &= ~((u32)clr[i] << (i * 8 + 4));
+			ts->write(ts->dev, 0x44 + i * 8,
+				  (ts->out_level >> (i * 8 + 4)) & 0xFF);
+		}
+	}
+
+	mutex_unlock(&ts->lock);
+}
+
 int __devinit __max730x_probe(struct max7301 *ts)
 {
 	struct device *dev = ts->dev;
@@ -183,8 +234,10 @@ int __devinit __max730x_probe(struct max
 
 	ts->chip.direction_input = max7301_direction_input;
 	ts->chip.get = max7301_get;
+	ts->chip.get_block = max7301_get_block;
 	ts->chip.direction_output = max7301_direction_output;
 	ts->chip.set = max7301_set;
+	ts->chip.set_block = max7301_set_block;
 
 	ts->chip.base = pdata->base;
 	ts->chip.ngpio = PIN_NUMBER;