linux-imx

/* NXP PCF50633 ADC Driver

 *

 * (C) 2006-2008 by Openmoko, Inc.

 * Author: Balaji Rao <balajirrao@openmoko.org>

 * All rights reserved.

 *

 * Broken down from monstrous PCF50633 driver mainly by

 * Harald Welte, Andy Green and Werner Almesberger

 *

 *  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.

 *

 *  NOTE: This driver does not yet support subtractive ADC mode, which means

 *  you can do only one measurement per read request.

 */

​

#include <linux/kernel.h>

#include <linux/slab.h>

#include <linux/module.h>

#include <linux/device.h>

#include <linux/platform_device.h>

#include <linux/completion.h>

​

#include <linux/mfd/pcf50633/core.h>

#include <linux/mfd/pcf50633/adc.h>

​

struct pcf50633_adc_request {

    int mux;

    int avg;

    void (*callback)(struct pcf50633 *, void *, int);

    void *callback_param;

};

​

struct pcf50633_adc_sync_request {

    int result;

    struct completion completion;

};

​

#define PCF50633_MAX_ADC_FIFO_DEPTH 8

​

struct pcf50633_adc {

    struct pcf50633 *pcf;

​

    /* Private stuff */

    struct pcf50633_adc_request *queue[PCF50633_MAX_ADC_FIFO_DEPTH];

    int queue_head;

    int queue_tail;

    struct mutex queue_mutex;

};

​

static inline struct pcf50633_adc *__to_adc(struct pcf50633 *pcf)

{

    return platform_get_drvdata(pcf->adc_pdev);

}

​

static void adc_setup(struct pcf50633 *pcf, int channel, int avg)

{

    channel &= PCF50633_ADCC1_ADCMUX_MASK;

​

    /* kill ratiometric, but enable ACCSW biasing */

    pcf50633_reg_write(pcf, PCF50633_REG_ADCC2, 0x00);