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>
(cherry picked from commit 3fa179c31ed1dea915aa758af3d53839c102dee5)

1 files changed, 73 insertions, 0 deletions

diff --git a/include/gpio_exp.h b/include/gpio_exp.h
new file mode 100644
index 0000000..6dc5eed
--- /dev/null
+++ b/include/gpio_exp.h
@@ -0,0 +1,73 @@
+/*
+ * 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.
+ */
+
+#ifndef __GPIO_EXP_H
+#define __GPIO_EXP_H
+
+#ifndef CONFIG_IOEXP_DEV_PINS_NUM
+#define CONFIG_IOEXP_DEV_PINS_NUM 8
+#endif
+
+#ifndef CONFIG_IOEXP_DEVICES_NUM
+#define CONFIG_IOEXP_DEVICES_NUM 1
+#endif
+
+/*Define for building ioexp gpio, port starts from 1, index starts from 0*/
+#define IOEXP_GPIO_NR(port, index) \
+	((((port)-1)*CONFIG_IOEXP_DEV_PINS_NUM)+ \
+	 ((index)&(CONFIG_IOEXP_DEV_PINS_NUM-1)))
+
+/*Get the device number from a ioexp gpio*/
+#define IOEXP_GPIO_TO_DEVICE(gpio_nr) \
+	(gpio_nr / CONFIG_IOEXP_DEV_PINS_NUM)
+
+/*Get the port number from a ioexp gpio*/
+#define IOEXP_GPIO_TO_PORT(gpio_nr) \
+	((gpio_nr / CONFIG_IOEXP_DEV_PINS_NUM) + 1)
+
+/*Get the pin number from a ioexp gpio*/
+#define IOEXP_GPIO_TO_PIN(gpio_nr) \
+	(gpio_nr % CONFIG_IOEXP_DEV_PINS_NUM)
+
+/**
+ * Make a GPIO an input.
+ *
+ * @param gpio	GPIO number
+ * @return 0 if ok, -1 on error
+ */
+int gpio_exp_direction_input(unsigned gpio);
+
+/**
+ * Make a GPIO an output, and set its value.
+ *
+ * @param gpio	GPIO number
+ * @param value	GPIO value (0 for low or 1 for high)
+ * @return 0 if ok, -1 on error
+ */
+int gpio_exp_direction_output(unsigned gpio, int value);
+
+/**
+ * Setup the io expander's port.
+ *
+ * @param port	IO expander port , starts from 1
+ * @param i2c_bus_id	i2c bus index, starts from 0
+ * @param i2c_slave_addr	i2c address of the io expander port
+ * @return 0 if ok, -1 on error
+ */
+int gpio_exp_setup_port(int port, int i2c_bus_id, int i2c_slave_addr);
+
+#endif	/*__GPIO_EXP_H*/