[PATCH RFC 4/6 v3] gpio-max730x: Add block GPIO API

[Roland Stigge]

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 at antcom.de>

---
 drivers/gpio/gpio-max730x.c |   60 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

--- linux-2.6.orig/drivers/gpio/gpio-max730x.c
+++ linux-2.6/drivers/gpio/gpio-max730x.c
@@ -146,6 +146,43 @@ static int max7301_get(struct gpio_chip
 	return level;
 }
 
+static unsigned max7301_get_block(struct gpio_chip *chip, unsigned mask)
+{
+	struct max7301 *ts = container_of(chip, struct max7301, chip);
+	int i, j;
+	unsigned result = 0;
+
+	for (i = 0; i < 4; i++) {
+		if ((mask >> (i * 8)) & 0xFF) { /* i/o only if necessary */
+			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);
+				}
+			}
+
+			result |= ((unsigned)(in_level & in_mask) |
+				   (out_level & out_mask)) << (i * 8);
+		}
+	}
+
+	return result & mask;
+}
+
 static void max7301_set(struct gpio_chip *chip, unsigned offset, int value)
 {
 	struct max7301 *ts = container_of(chip, struct max7301, chip);
@@ -160,6 +197,27 @@ static void max7301_set(struct gpio_chip
 	mutex_unlock(&ts->lock);
 }
 
+static
+void max7301_set_block(struct gpio_chip *chip, unsigned mask, unsigned values)
+{
+	struct max7301 *ts = container_of(chip, struct max7301, chip);
+	unsigned changes;
+	int i;
+
+	mutex_lock(&ts->lock);
+
+	changes = (ts->out_level ^ (values << 4)) & (mask << 4);
+	ts->out_level ^= changes;
+
+	for (i = 0; i < 4; i++) {
+		if ((changes >> (i * 8 + 4)) & 0xFF) /* i/o only on change */
+			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 +241,10 @@ 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;