linux-imx

/*

 * TI/National Semiconductor LP3943 MFD Core Driver

 *

 * Copyright 2013 Texas Instruments

 *

 * Author: Milo Kim <milo.kim@ti.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 *

 * Driver structure:

 *   LP3943 is an integrated device capable of driving 16 output channels.

 *   It can be used for a GPIO expander and PWM generators.

 *

 *                                   LED control    General usage for a device

 *                                   ___________   ____________________________

 *

 *   LP3943 MFD ---- GPIO expander    leds-gpio        eg) HW enable pin

 *               |

 *               --- PWM generator    leds-pwm         eg) PWM input

 *

 *   Internal two PWM channels are used for LED dimming effect.

 *   And each output pin can be used as a GPIO as well.

 *   The LED functionality can work with GPIOs or PWMs.

 *   LEDs can be controlled with legacy leds-gpio(static brightness) or

 *   leds-pwm drivers(dynamic brightness control).

 *   Alternatively, it can be used for generic GPIO and PWM controller.

 *   For example, a GPIO is HW enable pin of a device.

 *   A PWM is input pin of a backlight device.

 */

​

#include <linux/err.h>

#include <linux/gpio.h>

#include <linux/i2c.h>

#include <linux/mfd/core.h>

#include <linux/mfd/lp3943.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/slab.h>

​

#define LP3943_MAX_REGISTERS        0x09

​

/* Register configuration for pin MUX */

static const struct lp3943_reg_cfg lp3943_mux_cfg[] = {

    /* address, mask, shift */

    { LP3943_REG_MUX0, 0x03, 0 },

    { LP3943_REG_MUX0, 0x0C, 2 },

    { LP3943_REG_MUX0, 0x30, 4 },

    { LP3943_REG_MUX0, 0xC0, 6 },

    { LP3943_REG_MUX1, 0x03, 0 },

    { LP3943_REG_MUX1, 0x0C, 2 },

    { LP3943_REG_MUX1, 0x30, 4 },

    { LP3943_REG_MUX1, 0xC0, 6 },

    { LP3943_REG_MUX2, 0x03, 0 },

    { LP3943_REG_MUX2, 0x0C, 2 },

    { LP3943_REG_MUX2, 0x30, 4 },

    { LP3943_REG_MUX2, 0xC0, 6 },

    { LP3943_REG_MUX3, 0x03, 0 },

    { LP3943_REG_MUX3, 0x0C, 2 },

    { LP3943_REG_MUX3, 0x30, 4 },

    { LP3943_REG_MUX3, 0xC0, 6 },

};