ade7759.c

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/*
 * ADE7759 Active Energy Metering IC with di/dt Sensor Interface Driver
 *
 * Copyright 2010 Analog Devices Inc.
 *
 * Licensed under the GPL-2 or later.
 */

#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/delay.h>
#include <linux/mutex.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/spi/spi.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/list.h>
#include <linux/module.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include "meter.h"
#include "ade7759.h"

static int ade7759_spi_write_reg_8(struct device *dev,
        u8 reg_address,
        u8 val)
{
    int ret;
    struct iio_dev *indio_dev = dev_to_iio_dev(dev);
    struct ade7759_state *st = iio_priv(indio_dev);

    mutex_lock(&st->buf_lock);
    st->tx[0] = ADE7759_WRITE_REG(reg_address);
    st->tx[1] = val;

    ret = spi_write(st->us, st->tx, 2);
    mutex_unlock(&st->buf_lock);

    return ret;
}

static int ade7759_spi_write_reg_16(struct device *dev,
        u8 reg_address,
        u16 value)
{
    int ret;
    struct iio_dev *indio_dev = dev_to_iio_dev(dev);
    struct ade7759_state *st = iio_priv(indio_dev);

    mutex_lock(&st->buf_lock);
    st->tx[0] = ADE7759_WRITE_REG(reg_address);
    st->tx[1] = (value >> 8) & 0xFF;
    st->tx[2] = value & 0xFF;
    ret = spi_write(st->us, st->tx, 3);
    mutex_unlock(&st->buf_lock);

    return ret;
}

static int ade7759_spi_read_reg_8(struct device *dev,
        u8 reg_address,
        u8 *val)
{
    struct iio_dev *indio_dev = dev_to_iio_dev(dev);
    struct ade7759_state *st = iio_priv(indio_dev);
    int ret;

    ret = spi_w8r8(st->us, ADE7759_READ_REG(reg_address));
    if (ret < 0) {
        dev_err(&st->us->dev, "problem when reading 8 bit register 0x%02X",
                reg_address);
        return ret;
    }
    *val = ret;

    return 0;
}

static int ade7759_spi_read_reg_16(struct device *dev,
        u8 reg_address,
        u16 *val)
{
    struct iio_dev *indio_dev = dev_to_iio_dev(dev);
    struct ade7759_state *st = iio_priv(indio_dev);
    int ret;

    ret = spi_w8r16(st->us, ADE7759_READ_REG(reg_address));
    if (ret < 0) {
        dev_err(&st->us->dev, "problem when reading 16 bit register 0x%02X",
            reg_address);
        return ret;
    }

    *val = ret;
    *val = be16_to_cpup(val);

    return 0;
}

static int ade7759_spi_read_reg_40(struct device *dev,
        u8 reg_address,
        u64 *val)
{
    struct spi_message msg;
    struct iio_dev *indio_dev = dev_to_iio_dev(dev);
    struct ade7759_state *st = iio_priv(indio_dev);
    int ret;
    struct spi_transfer xfers[] = {
        {
            .tx_buf = st->tx,
            .rx_buf = st->rx,
            .bits_per_word = 8,
            .len = 6,
        },
    };

    mutex_lock(&st->buf_lock);
    st->tx[0] = ADE7759_READ_REG(reg_address);
    memset(&st->tx[1], 0 , 5);

    spi_message_init(&msg);
    spi_message_add_tail(xfers, &msg);
    ret = spi_sync(st->us, &msg);
    if (ret) {
        dev_err(&st->us->dev, "problem when reading 40 bit register 0x%02X",
                reg_address);
        goto error_ret;
    }
    *val = ((u64)st->rx[1] << 32) | (st->rx[2] << 24) |
        (st->rx[3] << 16) | (st->rx[4] << 8) | st->rx[5];

error_ret:
    mutex_unlock(&st->buf_lock);
    return ret;
}

static ssize_t ade7759_read_8bit(struct device *dev,
        struct device_attribute *attr,
        char *buf)
{
    int ret;
    u8 val = 0;
    struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);

    ret = ade7759_spi_read_reg_8(dev, this_attr->address, &val);
    if (ret)
        return ret;

    return sprintf(buf, "%u\n", val);
}

static ssize_t ade7759_read_16bit(struct device *dev,
        struct device_attribute *attr,
        char *buf)
{
    int ret;
    u16 val = 0;
    struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);

    ret = ade7759_spi_read_reg_16(dev, this_attr->address, &val);
    if (ret)
        return ret;

    return sprintf(buf, "%u\n", val);
}

static ssize_t ade7759_read_40bit(struct device *dev,
        struct device_attribute *attr,
        char *buf)
{
    int ret;
    u64 val = 0;
    struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);

    ret = ade7759_spi_read_reg_40(dev, this_attr->address, &val);
    if (ret)
        return ret;

    return sprintf(buf, "%llu\n", val);
}

static ssize_t ade7759_write_8bit(struct device *dev,
        struct device_attribute *attr,
        const char *buf,
        size_t len)
{
    struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
    int ret;
    long val;

    ret = strict_strtol(buf, 10, &val);
    if (ret)
        goto error_ret;
    ret = ade7759_spi_write_reg_8(dev, this_attr->address, val);

error_ret:
    return ret ? ret : len;
}

static ssize_t ade7759_write_16bit(struct device *dev,
        struct device_attribute *attr,
        const char *buf,
        size_t len)
{
    struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
    int ret;
    long val;

    ret = strict_strtol(buf, 10, &val);
    if (ret)
        goto error_ret;
    ret = ade7759_spi_write_reg_16(dev, this_attr->address, val);

error_ret:
    return ret ? ret : len;
}

static int ade7759_reset(struct device *dev)
{
    int ret;
    u16 val;
    ade7759_spi_read_reg_16(dev,
            ADE7759_MODE,
            &val);
    val |= 1 << 6; /* Software Chip Reset */
    ret = ade7759_spi_write_reg_16(dev,
            ADE7759_MODE,
            val);

    return ret;
}

static ssize_t ade7759_write_reset(struct device *dev,
        struct device_attribute *attr,
        const char *buf, size_t len)
{
    if (len < 1)
        return -1;
    switch (buf[0]) {
    case '1':
    case 'y':
    case 'Y':
        return ade7759_reset(dev);
    }
    return -1;
}

static IIO_DEV_ATTR_AENERGY(ade7759_read_40bit, ADE7759_AENERGY);
static IIO_DEV_ATTR_CFDEN(S_IWUSR | S_IRUGO,
        ade7759_read_16bit,
        ade7759_write_16bit,
        ADE7759_CFDEN);
static IIO_DEV_ATTR_CFNUM(S_IWUSR | S_IRUGO,
        ade7759_read_8bit,
        ade7759_write_8bit,
        ADE7759_CFNUM);
static IIO_DEV_ATTR_CHKSUM(ade7759_read_8bit, ADE7759_CHKSUM);
static IIO_DEV_ATTR_PHCAL(S_IWUSR | S_IRUGO,
        ade7759_read_16bit,
        ade7759_write_16bit,
        ADE7759_PHCAL);
static IIO_DEV_ATTR_APOS(S_IWUSR | S_IRUGO,
        ade7759_read_16bit,
        ade7759_write_16bit,
        ADE7759_APOS);
static IIO_DEV_ATTR_SAGCYC(S_IWUSR | S_IRUGO,
        ade7759_read_8bit,
        ade7759_write_8bit,
        ADE7759_SAGCYC);
static IIO_DEV_ATTR_SAGLVL(S_IWUSR | S_IRUGO,
        ade7759_read_8bit,
        ade7759_write_8bit,
        ADE7759_SAGLVL);
static IIO_DEV_ATTR_LINECYC(S_IWUSR | S_IRUGO,
        ade7759_read_8bit,
        ade7759_write_8bit,
        ADE7759_LINECYC);
static IIO_DEV_ATTR_LENERGY(ade7759_read_40bit, ADE7759_LENERGY);
static IIO_DEV_ATTR_PGA_GAIN(S_IWUSR | S_IRUGO,
        ade7759_read_8bit,
        ade7759_write_8bit,
        ADE7759_GAIN);
static IIO_DEV_ATTR_ACTIVE_POWER_GAIN(S_IWUSR | S_IRUGO,
        ade7759_read_16bit,
        ade7759_write_16bit,
        ADE7759_APGAIN);
static IIO_DEV_ATTR_CH_OFF(1, S_IWUSR | S_IRUGO,
        ade7759_read_8bit,
        ade7759_write_8bit,
        ADE7759_CH1OS);
static IIO_DEV_ATTR_CH_OFF(2, S_IWUSR | S_IRUGO,
        ade7759_read_8bit,
        ade7759_write_8bit,
        ADE7759_CH2OS);

static int ade7759_set_irq(struct device *dev, bool enable)
{
    int ret;
    u8 irqen;
    ret = ade7759_spi_read_reg_8(dev, ADE7759_IRQEN, &irqen);
    if (ret)
        goto error_ret;

    if (enable)
        irqen |= 1 << 3; /* Enables an interrupt when a data is
                    present in the waveform register */
    else
        irqen &= ~(1 << 3);

    ret = ade7759_spi_write_reg_8(dev, ADE7759_IRQEN, irqen);

error_ret:
    return ret;
}

/* Power down the device */
static int ade7759_stop_device(struct device *dev)
{
    u16 val;

    ade7759_spi_read_reg_16(dev,
            ADE7759_MODE,
            &val);
    val |= 1 << 4;  /* AD converters can be turned off */

    return ade7759_spi_write_reg_16(dev, ADE7759_MODE, val);
}

static int ade7759_initial_setup(struct iio_dev *indio_dev)
{
    int ret;
    struct ade7759_state *st = iio_priv(indio_dev);
    struct device *dev = &indio_dev->dev;

    /* use low spi speed for init */
    st->us->mode = SPI_MODE_3;
    spi_setup(st->us);

    /* Disable IRQ */
    ret = ade7759_set_irq(dev, false);
    if (ret) {
        dev_err(dev, "disable irq failed");
        goto err_ret;
    }

    ade7759_reset(dev);
    msleep(ADE7759_STARTUP_DELAY);

err_ret:
    return ret;
}

static ssize_t ade7759_read_frequency(struct device *dev,
        struct device_attribute *attr,
        char *buf)
{
    int ret;
    u16 t;
    int sps;
    ret = ade7759_spi_read_reg_16(dev,
            ADE7759_MODE,
            &t);
    if (ret)
        return ret;

    t = (t >> 3) & 0x3;
    sps = 27900 / (1 + t);

    return sprintf(buf, "%d\n", sps);
}

static ssize_t ade7759_write_frequency(struct device *dev,
        struct device_attribute *attr,
        const char *buf,
        size_t len)
{
    struct iio_dev *indio_dev = dev_to_iio_dev(dev);
    struct ade7759_state *st = iio_priv(indio_dev);
    unsigned long val;
    int ret;
    u16 reg, t;

    ret = strict_strtol(buf, 10, &val);
    if (ret)
        return ret;
    if (val == 0)
        return -EINVAL;

    mutex_lock(&indio_dev->mlock);

    t = (27900 / val);
    if (t > 0)
        t--;

    if (t > 1)
        st->us->max_speed_hz = ADE7759_SPI_SLOW;
    else
        st->us->max_speed_hz = ADE7759_SPI_FAST;

    ret = ade7759_spi_read_reg_16(dev, ADE7759_MODE, &reg);
    if (ret)
        goto out;

    reg &= ~(3 << 13);
    reg |= t << 13;

    ret = ade7759_spi_write_reg_16(dev, ADE7759_MODE, reg);

out:
    mutex_unlock(&indio_dev->mlock);

    return ret ? ret : len;
}
static IIO_DEV_ATTR_TEMP_RAW(ade7759_read_8bit);
static IIO_CONST_ATTR(in_temp_offset, "70 C");
static IIO_CONST_ATTR(in_temp_scale, "1 C");

static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO,
        ade7759_read_frequency,
        ade7759_write_frequency);

static IIO_DEV_ATTR_RESET(ade7759_write_reset);

static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("27900 14000 7000 3500");

static struct attribute *ade7759_attributes[] = {
    &iio_dev_attr_in_temp_raw.dev_attr.attr,
    &iio_const_attr_in_temp_offset.dev_attr.attr,
    &iio_const_attr_in_temp_scale.dev_attr.attr,
    &iio_dev_attr_sampling_frequency.dev_attr.attr,
    &iio_const_attr_sampling_frequency_available.dev_attr.attr,
    &iio_dev_attr_reset.dev_attr.attr,
    &iio_dev_attr_phcal.dev_attr.attr,
    &iio_dev_attr_cfden.dev_attr.attr,
    &iio_dev_attr_aenergy.dev_attr.attr,
    &iio_dev_attr_cfnum.dev_attr.attr,
    &iio_dev_attr_apos.dev_attr.attr,
    &iio_dev_attr_sagcyc.dev_attr.attr,
    &iio_dev_attr_saglvl.dev_attr.attr,
    &iio_dev_attr_linecyc.dev_attr.attr,
    &iio_dev_attr_lenergy.dev_attr.attr,
    &iio_dev_attr_chksum.dev_attr.attr,
    &iio_dev_attr_pga_gain.dev_attr.attr,
    &iio_dev_attr_active_power_gain.dev_attr.attr,
    &iio_dev_attr_choff_1.dev_attr.attr,
    &iio_dev_attr_choff_2.dev_attr.attr,
    NULL,
};

static const struct attribute_group ade7759_attribute_group = {
    .attrs = ade7759_attributes,
};

static const struct iio_info ade7759_info = {
    .attrs = &ade7759_attribute_group,
    .driver_module = THIS_MODULE,
};

static int __devinit ade7759_probe(struct spi_device *spi)
{
    int ret;
    struct ade7759_state *st;
    struct iio_dev *indio_dev;

    /* setup the industrialio driver allocated elements */
    indio_dev = iio_device_alloc(sizeof(*st));
    if (indio_dev == NULL) {
        ret = -ENOMEM;
        goto error_ret;
    }
    /* this is only used for removal purposes */
    spi_set_drvdata(spi, indio_dev);

    st = iio_priv(indio_dev);
    st->us = spi;
    mutex_init(&st->buf_lock);
    indio_dev->name = spi->dev.driver->name;
    indio_dev->dev.parent = &spi->dev;
    indio_dev->info = &ade7759_info;
    indio_dev->modes = INDIO_DIRECT_MODE;

    /* Get the device into a sane initial state */
    ret = ade7759_initial_setup(indio_dev);
    if (ret)
        goto error_free_dev;

    ret = iio_device_register(indio_dev);
    if (ret)
        goto error_free_dev;

    return 0;

error_free_dev:
    iio_device_free(indio_dev);
error_ret:
    return ret;
}

/* fixme, confirm ordering in this function */
static int __devexit ade7759_remove(struct spi_device *spi)
{
    struct iio_dev *indio_dev = spi_get_drvdata(spi);

    iio_device_unregister(indio_dev);
    ade7759_stop_device(&indio_dev->dev);
    iio_device_free(indio_dev);

    return 0;
}

static struct spi_driver ade7759_driver = {
    .driver = {
        .name = "ade7759",
        .owner = THIS_MODULE,
    },
    .probe = ade7759_probe,
    .remove = __devexit_p(ade7759_remove),
};
module_spi_driver(ade7759_driver);

MODULE_AUTHOR("Barry Song <[email protected]>");
MODULE_DESCRIPTION("Analog Devices ADE7759 Active Energy Metering IC Driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("spi:ad7759");