ENGR00294905 driver:MAX7310: Add GPIO expander driver for MAX7310

Implement simple functionalities for MAX7310 GPIO input and output.
Because MAX7310 is a off-chip device and need to co-exist with
on-chip GPIO, new APIs are added specifically for expander device.

CONFIG_MAX7310_IOEXP is used to enable the MAX7310 driver. The I2C
related configurations also need to set together.

Signed-off-by: Ye.Li <B37916@freescale.com>

2 files changed, 168 insertions, 0 deletions

diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 9df1e26..e46fd0f 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -47,6 +47,7 @@ COBJS-$(CONFIG_OMAP_GPIO)	+= omap_gpio.o
 COBJS-$(CONFIG_DB8500_GPIO)	+= db8500_gpio.o
 COBJS-$(CONFIG_BCM2835_GPIO)	+= bcm2835_gpio.o
 COBJS-$(CONFIG_S3C2440_GPIO)	+= s3c2440_gpio.o
+COBJS-$(CONFIG_MAX7310_IOEXP)	+= max7310_ioexp.o
 
 COBJS	:= $(COBJS-y)
 SRCS 	:= $(COBJS:.o=.c)
diff --git a/drivers/gpio/max7310_ioexp.c b/drivers/gpio/max7310_ioexp.c
new file mode 100644
index 0000000..34c494f
--- /dev/null
+++ b/drivers/gpio/max7310_ioexp.c
@@ -0,0 +1,167 @@
+/*
+ * Copyright (C) 2014 Freescale Semiconductor, Inc.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <common.h>
+#include <asm/gpio.h>
+#include <asm/io.h>
+#include <errno.h>
+#include <i2c.h>
+#include <gpio_exp.h>
+
+#define MAX7310_REG_INPUT_PORT          0x00
+#define MAX7310_REG_OUTPUT_PORT         0x01
+#define MAX7310_REG_POLARITY            0x02
+#define MAX7310_REG_CONFIGURATION       0x03
+#define MAX7310_REG_TIMEOUT             0x04
+
+enum max7310_gpio_direction {
+	MAX7310_GPIO_DIRECTION_IN,
+	MAX7310_GPIO_DIRECTION_OUT,
+};
+
+struct max7310_config_struct {
+	int i2c_slave_addr;
+	int i2c_bus_id;
+};
+
+static struct max7310_config_struct max7310_configs[CONFIG_IOEXP_DEVICES_NUM];
+
+
+static int max7310_gpio_direction(unsigned int gpio,
+	enum max7310_gpio_direction direction)
+{
+	unsigned int dev = IOEXP_GPIO_TO_DEVICE(gpio);
+	unsigned int pin = IOEXP_GPIO_TO_PIN(gpio);
+	unsigned char value, val2, val3;
+	unsigned char chip;
+
+	if (dev >= CONFIG_IOEXP_DEVICES_NUM)
+		return -EPERM;
+
+	chip = max7310_configs[dev].i2c_slave_addr;
+
+	i2c_set_bus_num(max7310_configs[dev].i2c_bus_id);
+	if (i2c_probe(chip))
+		return -ENXIO;
+
+	i2c_read(chip, MAX7310_REG_CONFIGURATION, 1, &value, 1);
+
+	switch (direction) {
+	case MAX7310_GPIO_DIRECTION_OUT:
+		value &= ~(1 << pin);
+		i2c_write(chip, MAX7310_REG_CONFIGURATION, 1, &value, 1);
+		break;
+	case MAX7310_GPIO_DIRECTION_IN:
+
+		i2c_read(chip, MAX7310_REG_POLARITY, 1, &val2, 1);
+		i2c_read(chip, MAX7310_REG_OUTPUT_PORT, 1, &val3, 1);
+
+		value |= (1 << pin);
+		val2 &= ~(1 << pin);
+		val3 &= ~(1 << pin);
+
+		i2c_write(chip, MAX7310_REG_POLARITY, 1, &val2, 1);
+		i2c_write(chip, MAX7310_REG_CONFIGURATION, 1, &value, 1);
+		i2c_write(chip, MAX7310_REG_OUTPUT_PORT, 1, &val3, 1);
+
+		break;
+	}
+
+	return 0;
+}
+
+static int max7310_gpio_set_value(unsigned gpio, int value)
+{
+	unsigned int dev = IOEXP_GPIO_TO_DEVICE(gpio);
+	unsigned int pin = IOEXP_GPIO_TO_PIN(gpio);
+	unsigned char reg_val;
+	unsigned char chip;
+
+	if (dev >= CONFIG_IOEXP_DEVICES_NUM)
+		return -EPERM;
+
+	chip = max7310_configs[dev].i2c_slave_addr;
+
+	i2c_set_bus_num(max7310_configs[dev].i2c_bus_id);
+	if (i2c_probe(chip))
+		return -ENXIO;
+
+	i2c_read(chip, MAX7310_REG_OUTPUT_PORT, 1, &reg_val, 1);
+
+	if (value)
+		reg_val |= 1 << pin;
+	else
+		reg_val &= ~(1 << pin);
+
+	i2c_write(chip, MAX7310_REG_OUTPUT_PORT, 1, &reg_val, 1);
+
+	return 0;
+}
+
+static int max7310_gpio_get_value(unsigned gpio)
+{
+	unsigned int dev = IOEXP_GPIO_TO_DEVICE(gpio);
+	unsigned int pin = IOEXP_GPIO_TO_PIN(gpio);
+	unsigned char reg_val;
+	unsigned char chip;
+
+	if (dev >= CONFIG_IOEXP_DEVICES_NUM)
+		return -EPERM;
+
+	chip = max7310_configs[dev].i2c_slave_addr;
+
+	i2c_set_bus_num(max7310_configs[dev].i2c_bus_id);
+	if (i2c_probe(chip))
+		return -ENXIO;
+
+	i2c_read(chip, MAX7310_REG_INPUT_PORT, 1, &reg_val, 1);
+
+	reg_val = (reg_val >> pin) & 0x01;
+
+	return reg_val;
+}
+
+int gpio_exp_direction_input(unsigned gpio)
+{
+	int ret = max7310_gpio_direction(gpio, MAX7310_GPIO_DIRECTION_IN);
+
+	if (ret < 0)
+		return ret;
+
+	return max7310_gpio_get_value(gpio);
+}
+
+int gpio_exp_direction_output(unsigned gpio, int value)
+{
+	int ret = max7310_gpio_direction(gpio, MAX7310_GPIO_DIRECTION_OUT);
+
+	if (ret < 0)
+		return ret;
+
+	return max7310_gpio_set_value(gpio, value);
+}
+
+int gpio_exp_setup_port(int port, int i2c_bus_id, int i2c_slave_addr)
+{
+	if (port > CONFIG_IOEXP_DEVICES_NUM || port <= 0)
+		return -EPERM;
+
+	max7310_configs[port-1].i2c_bus_id = i2c_bus_id;
+	max7310_configs[port-1].i2c_slave_addr = i2c_slave_addr;
+
+	return 0;
+}