x86/xen: resume timer irqs early

[linux/fpc-iii.git] / drivers / iio / dac / ad5791.c

/*
 * AD5760, AD5780, AD5781, AD5790, AD5791 Voltage Output Digital to Analog
 * Converter
 *
 * Copyright 2011 Analog Devices Inc.
 *
 * Licensed under the GPL-2.
 */

#include <linux/interrupt.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/spi/spi.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/regulator/consumer.h>
#include <linux/module.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/dac/ad5791.h>

#define AD5791_RES_MASK(x)              ((1 << (x)) - 1)
#define AD5791_DAC_MASK                 AD5791_RES_MASK(20)
#define AD5791_DAC_MSB                  (1 << 19)

#define AD5791_CMD_READ                 (1 << 23)
#define AD5791_CMD_WRITE                (0 << 23)
#define AD5791_ADDR(addr)               ((addr) << 20)

/* Registers */
#define AD5791_ADDR_NOOP                0
#define AD5791_ADDR_DAC0                1
#define AD5791_ADDR_CTRL                2
#define AD5791_ADDR_CLRCODE             3
#define AD5791_ADDR_SW_CTRL             4

/* Control Register */
#define AD5791_CTRL_RBUF                (1 << 1)
#define AD5791_CTRL_OPGND               (1 << 2)
#define AD5791_CTRL_DACTRI              (1 << 3)
#define AD5791_CTRL_BIN2SC              (1 << 4)
#define AD5791_CTRL_SDODIS              (1 << 5)
#define AD5761_CTRL_LINCOMP(x)          ((x) << 6)

#define AD5791_LINCOMP_0_10             0
#define AD5791_LINCOMP_10_12            1
#define AD5791_LINCOMP_12_16            2
#define AD5791_LINCOMP_16_19            3
#define AD5791_LINCOMP_19_20            12

#define AD5780_LINCOMP_0_10             0
#define AD5780_LINCOMP_10_20            12

/* Software Control Register */
#define AD5791_SWCTRL_LDAC              (1 << 0)
#define AD5791_SWCTRL_CLR               (1 << 1)
#define AD5791_SWCTRL_RESET             (1 << 2)

#define AD5791_DAC_PWRDN_6K             0
#define AD5791_DAC_PWRDN_3STATE         1

/**
 * struct ad5791_chip_info - chip specific information
 * @get_lin_comp:       function pointer to the device specific function
 */

struct ad5791_chip_info {
        int (*get_lin_comp)     (unsigned int span);
};

/**
 * struct ad5791_state - driver instance specific data
 * @us:                 spi_device
 * @reg_vdd:            positive supply regulator
 * @reg_vss:            negative supply regulator
 * @chip_info:          chip model specific constants
 * @vref_mv:            actual reference voltage used
 * @vref_neg_mv:        voltage of the negative supply
 * @pwr_down_mode       current power down mode
 */

struct ad5791_state {
        struct spi_device               *spi;
        struct regulator                *reg_vdd;
        struct regulator                *reg_vss;
        const struct ad5791_chip_info   *chip_info;
        unsigned short                  vref_mv;
        unsigned int                    vref_neg_mv;
        unsigned                        ctrl;
        unsigned                        pwr_down_mode;
        bool                            pwr_down;
};

/**
 * ad5791_supported_device_ids:
 */

enum ad5791_supported_device_ids {
        ID_AD5760,
        ID_AD5780,
        ID_AD5781,
        ID_AD5791,
};

static int ad5791_spi_write(struct spi_device *spi, u8 addr, u32 val)
{
        union {
                u32 d32;
                u8 d8[4];
        } data;

        data.d32 = cpu_to_be32(AD5791_CMD_WRITE |
                              AD5791_ADDR(addr) |
                              (val & AD5791_DAC_MASK));

        return spi_write(spi, &data.d8[1], 3);
}

static int ad5791_spi_read(struct spi_device *spi, u8 addr, u32 *val)
{
        union {
                u32 d32;
                u8 d8[4];
        } data[3];
        int ret;
        struct spi_transfer xfers[] = {
                {
                        .tx_buf = &data[0].d8[1],
                        .bits_per_word = 8,
                        .len = 3,
                        .cs_change = 1,
                }, {
                        .tx_buf = &data[1].d8[1],
                        .rx_buf = &data[2].d8[1],
                        .bits_per_word = 8,
                        .len = 3,
                },
        };

        data[0].d32 = cpu_to_be32(AD5791_CMD_READ |
                              AD5791_ADDR(addr));
        data[1].d32 = cpu_to_be32(AD5791_ADDR(AD5791_ADDR_NOOP));

        ret = spi_sync_transfer(spi, xfers, ARRAY_SIZE(xfers));

        *val = be32_to_cpu(data[2].d32);

        return ret;
}

static const char * const ad5791_powerdown_modes[] = {
        "6kohm_to_gnd",
        "three_state",
};

static int ad5791_get_powerdown_mode(struct iio_dev *indio_dev,
        const struct iio_chan_spec *chan)
{
        struct ad5791_state *st = iio_priv(indio_dev);

        return st->pwr_down_mode;
}

static int ad5791_set_powerdown_mode(struct iio_dev *indio_dev,
        const struct iio_chan_spec *chan, unsigned int mode)
{
        struct ad5791_state *st = iio_priv(indio_dev);

        st->pwr_down_mode = mode;

        return 0;
}

static const struct iio_enum ad5791_powerdown_mode_enum = {
        .items = ad5791_powerdown_modes,
        .num_items = ARRAY_SIZE(ad5791_powerdown_modes),
        .get = ad5791_get_powerdown_mode,
        .set = ad5791_set_powerdown_mode,
};

static ssize_t ad5791_read_dac_powerdown(struct iio_dev *indio_dev,
        uintptr_t private, const struct iio_chan_spec *chan, char *buf)
{
        struct ad5791_state *st = iio_priv(indio_dev);

        return sprintf(buf, "%d\n", st->pwr_down);
}

static ssize_t ad5791_write_dac_powerdown(struct iio_dev *indio_dev,
         uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
         size_t len)
{
        bool pwr_down;
        int ret;
        struct ad5791_state *st = iio_priv(indio_dev);

        ret = strtobool(buf, &pwr_down);
        if (ret)
                return ret;

        if (!pwr_down) {
                st->ctrl &= ~(AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI);
        } else {
                if (st->pwr_down_mode == AD5791_DAC_PWRDN_6K)
                        st->ctrl |= AD5791_CTRL_OPGND;
                else if (st->pwr_down_mode == AD5791_DAC_PWRDN_3STATE)
                        st->ctrl |= AD5791_CTRL_DACTRI;
        }
        st->pwr_down = pwr_down;

        ret = ad5791_spi_write(st->spi, AD5791_ADDR_CTRL, st->ctrl);

        return ret ? ret : len;
}

static int ad5791_get_lin_comp(unsigned int span)
{
        if (span <= 10000)
                return AD5791_LINCOMP_0_10;
        else if (span <= 12000)
                return AD5791_LINCOMP_10_12;
        else if (span <= 16000)
                return AD5791_LINCOMP_12_16;
        else if (span <= 19000)
                return AD5791_LINCOMP_16_19;
        else
                return AD5791_LINCOMP_19_20;
}

static int ad5780_get_lin_comp(unsigned int span)
{
        if (span <= 10000)
                return AD5780_LINCOMP_0_10;
        else
                return AD5780_LINCOMP_10_20;
}
static const struct ad5791_chip_info ad5791_chip_info_tbl[] = {
        [ID_AD5760] = {
                .get_lin_comp = ad5780_get_lin_comp,
        },
        [ID_AD5780] = {
                .get_lin_comp = ad5780_get_lin_comp,
        },
        [ID_AD5781] = {
                .get_lin_comp = ad5791_get_lin_comp,
        },
        [ID_AD5791] = {
                .get_lin_comp = ad5791_get_lin_comp,
        },
};

static int ad5791_read_raw(struct iio_dev *indio_dev,
                           struct iio_chan_spec const *chan,
                           int *val,
                           int *val2,
                           long m)
{
        struct ad5791_state *st = iio_priv(indio_dev);
        u64 val64;
        int ret;

        switch (m) {
        case IIO_CHAN_INFO_RAW:
                ret = ad5791_spi_read(st->spi, chan->address, val);
                if (ret)
                        return ret;
                *val &= AD5791_DAC_MASK;
                *val >>= chan->scan_type.shift;
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_SCALE:
                *val = 0;
                *val2 = (((u64)st->vref_mv) * 1000000ULL) >> chan->scan_type.realbits;
                return IIO_VAL_INT_PLUS_MICRO;
        case IIO_CHAN_INFO_OFFSET:
                val64 = (((u64)st->vref_neg_mv) << chan->scan_type.realbits);
                do_div(val64, st->vref_mv);
                *val = -val64;
                return IIO_VAL_INT;
        default:
                return -EINVAL;
        }

};

static const struct iio_chan_spec_ext_info ad5791_ext_info[] = {
        {
                .name = "powerdown",
                .shared = true,
                .read = ad5791_read_dac_powerdown,
                .write = ad5791_write_dac_powerdown,
        },
        IIO_ENUM("powerdown_mode", true, &ad5791_powerdown_mode_enum),
        IIO_ENUM_AVAILABLE("powerdown_mode", &ad5791_powerdown_mode_enum),
        { },
};

#define AD5791_CHAN(bits, shift) {                      \
        .type = IIO_VOLTAGE,                            \
        .output = 1,                                    \
        .indexed = 1,                                   \
        .address = AD5791_ADDR_DAC0,                    \
        .channel = 0,                                   \
        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),   \
        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |  \
                BIT(IIO_CHAN_INFO_OFFSET),              \
        .scan_type = IIO_ST('u', bits, 24, shift),      \
        .ext_info = ad5791_ext_info,                    \
}

static const struct iio_chan_spec ad5791_channels[] = {
        [ID_AD5760] = AD5791_CHAN(16, 4),
        [ID_AD5780] = AD5791_CHAN(18, 2),
        [ID_AD5781] = AD5791_CHAN(18, 2),
        [ID_AD5791] = AD5791_CHAN(20, 0)
};

static int ad5791_write_raw(struct iio_dev *indio_dev,
                            struct iio_chan_spec const *chan,
                            int val,
                            int val2,
                            long mask)
{
        struct ad5791_state *st = iio_priv(indio_dev);

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                val &= AD5791_RES_MASK(chan->scan_type.realbits);
                val <<= chan->scan_type.shift;

                return ad5791_spi_write(st->spi, chan->address, val);

        default:
                return -EINVAL;
        }
}

static const struct iio_info ad5791_info = {
        .read_raw = &ad5791_read_raw,
        .write_raw = &ad5791_write_raw,
        .driver_module = THIS_MODULE,
};

static int ad5791_probe(struct spi_device *spi)
{
        struct ad5791_platform_data *pdata = spi->dev.platform_data;
        struct iio_dev *indio_dev;
        struct ad5791_state *st;
        int ret, pos_voltage_uv = 0, neg_voltage_uv = 0;

        indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
        if (!indio_dev)
                return -ENOMEM;
        st = iio_priv(indio_dev);
        st->reg_vdd = devm_regulator_get(&spi->dev, "vdd");
        if (!IS_ERR(st->reg_vdd)) {
                ret = regulator_enable(st->reg_vdd);
                if (ret)
                        return ret;

                ret = regulator_get_voltage(st->reg_vdd);
                if (ret < 0)
                        goto error_disable_reg_pos;

                pos_voltage_uv = ret;
        }

        st->reg_vss = devm_regulator_get(&spi->dev, "vss");
        if (!IS_ERR(st->reg_vss)) {
                ret = regulator_enable(st->reg_vss);
                if (ret)
                        goto error_disable_reg_pos;

                ret = regulator_get_voltage(st->reg_vss);
                if (ret < 0)
                        goto error_disable_reg_neg;

                neg_voltage_uv = ret;
        }

        st->pwr_down = true;
        st->spi = spi;

        if (!IS_ERR(st->reg_vss) && !IS_ERR(st->reg_vdd)) {
                st->vref_mv = (pos_voltage_uv + neg_voltage_uv) / 1000;
                st->vref_neg_mv = neg_voltage_uv / 1000;
        } else if (pdata) {
                st->vref_mv = pdata->vref_pos_mv + pdata->vref_neg_mv;
                st->vref_neg_mv = pdata->vref_neg_mv;
        } else {
                dev_warn(&spi->dev, "reference voltage unspecified\n");
        }

        ret = ad5791_spi_write(spi, AD5791_ADDR_SW_CTRL, AD5791_SWCTRL_RESET);
        if (ret)
                goto error_disable_reg_neg;

        st->chip_info = &ad5791_chip_info_tbl[spi_get_device_id(spi)
                                              ->driver_data];


        st->ctrl = AD5761_CTRL_LINCOMP(st->chip_info->get_lin_comp(st->vref_mv))
                  | ((pdata && pdata->use_rbuf_gain2) ? 0 : AD5791_CTRL_RBUF) |
                  AD5791_CTRL_BIN2SC;

        ret = ad5791_spi_write(spi, AD5791_ADDR_CTRL, st->ctrl |
                AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI);
        if (ret)
                goto error_disable_reg_neg;

        spi_set_drvdata(spi, indio_dev);
        indio_dev->dev.parent = &spi->dev;
        indio_dev->info = &ad5791_info;
        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->channels
                = &ad5791_channels[spi_get_device_id(spi)->driver_data];
        indio_dev->num_channels = 1;
        indio_dev->name = spi_get_device_id(st->spi)->name;
        ret = iio_device_register(indio_dev);
        if (ret)
                goto error_disable_reg_neg;

        return 0;

error_disable_reg_neg:
        if (!IS_ERR(st->reg_vss))
                regulator_disable(st->reg_vss);
error_disable_reg_pos:
        if (!IS_ERR(st->reg_vdd))
                regulator_disable(st->reg_vdd);
        return ret;
}

static int ad5791_remove(struct spi_device *spi)
{
        struct iio_dev *indio_dev = spi_get_drvdata(spi);
        struct ad5791_state *st = iio_priv(indio_dev);

        iio_device_unregister(indio_dev);
        if (!IS_ERR(st->reg_vdd))
                regulator_disable(st->reg_vdd);

        if (!IS_ERR(st->reg_vss))
                regulator_disable(st->reg_vss);

        return 0;
}

static const struct spi_device_id ad5791_id[] = {
        {"ad5760", ID_AD5760},
        {"ad5780", ID_AD5780},
        {"ad5781", ID_AD5781},
        {"ad5790", ID_AD5791},
        {"ad5791", ID_AD5791},
        {}
};
MODULE_DEVICE_TABLE(spi, ad5791_id);

static struct spi_driver ad5791_driver = {
        .driver = {
                   .name = "ad5791",
                   .owner = THIS_MODULE,
                   },
        .probe = ad5791_probe,
        .remove = ad5791_remove,
        .id_table = ad5791_id,
};
module_spi_driver(ad5791_driver);

MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("Analog Devices AD5760/AD5780/AD5781/AD5790/AD5791 DAC");
MODULE_LICENSE("GPL v2");