linux-imx

/*

 * ti-dac5571.c - Texas Instruments 8/10/12-bit 1/4-channel DAC driver

 *

 * Copyright (C) 2018 Prevas A/S

 *

 * http://www.ti.com/lit/ds/symlink/dac5571.pdf

 * http://www.ti.com/lit/ds/symlink/dac6571.pdf

 * http://www.ti.com/lit/ds/symlink/dac7571.pdf

 * http://www.ti.com/lit/ds/symlink/dac5574.pdf

 * http://www.ti.com/lit/ds/symlink/dac6574.pdf

 * http://www.ti.com/lit/ds/symlink/dac7574.pdf

 * http://www.ti.com/lit/ds/symlink/dac5573.pdf

 * http://www.ti.com/lit/ds/symlink/dac6573.pdf

 * http://www.ti.com/lit/ds/symlink/dac7573.pdf

 *

 * 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.

 */

​

#include <linux/iio/iio.h>

#include <linux/i2c.h>

#include <linux/module.h>

#include <linux/of_device.h>

#include <linux/of.h>

#include <linux/regulator/consumer.h>

​

enum chip_id {

    single_8bit, single_10bit, single_12bit,

    quad_8bit, quad_10bit, quad_12bit

};

​

struct dac5571_spec {

    u8 num_channels;

    u8 resolution;

};

​

static const struct dac5571_spec dac5571_spec[] = {

    [single_8bit]  = {.num_channels = 1, .resolution =  8},

    [single_10bit] = {.num_channels = 1, .resolution = 10},

    [single_12bit] = {.num_channels = 1, .resolution = 12},

    [quad_8bit]    = {.num_channels = 4, .resolution =  8},

    [quad_10bit]   = {.num_channels = 4, .resolution = 10},

    [quad_12bit]   = {.num_channels = 4, .resolution = 12},

};

​

struct dac5571_data {

    struct i2c_client *client;

    int id;

    struct mutex lock;

    struct regulator *vref;

    u16 val[4];

    bool powerdown;

    u8 powerdown_mode;

    struct dac5571_spec const *spec;

    int (*dac5571_cmd)(struct dac5571_data *data, int channel, u16 val);

    int (*dac5571_pwrdwn)(struct dac5571_data *data, int channel, u8 pwrdwn);

    u8 buf[3] ____cacheline_aligned;

};

​

#define DAC5571_POWERDOWN(mode)     ((mode) + 1)

#define DAC5571_POWERDOWN_FLAG      BIT(0)

#define DAC5571_CHANNEL_SELECT      1

#define DAC5571_LOADMODE_DIRECT     BIT(4)

#define DAC5571_SINGLE_PWRDWN_BITS  4

#define DAC5571_QUAD_PWRDWN_BITS    6

​

static int dac5571_cmd_single(struct dac5571_data *data, int channel, u16 val)

{

    unsigned int shift;

​

    shift = 12 - data->spec->resolution;

    data->buf[1] = val << shift;

    data->buf[0] = val >> (8 - shift);

​

    if (i2c_master_send(data->client, data->buf, 2) != 2)

        return -EIO;

​

    return 0;

}

​

static int dac5571_cmd_quad(struct dac5571_data *data, int channel, u16 val)

{

    unsigned int shift;

​

    shift = 16 - data->spec->resolution;

    data->buf[2] = val << shift;

    data->buf[1] = (val >> (8 - shift));

    data->buf[0] = (channel << DAC5571_CHANNEL_SELECT) |

               DAC5571_LOADMODE_DIRECT;

​

    if (i2c_master_send(data->client, data->buf, 3) != 3)