LXR linux/drivers/iio/dac/ad5592r.c

   1/*
   2 * AD5592R Digital <-> Analog converters driver
   3 *
   4 * Copyright 2015-2016 Analog Devices Inc.
   5 * Author: Paul Cercueil <paul.cercueil@analog.com>
   6 *
   7 * Licensed under the GPL-2.
   8 */
   9
  10#include "ad5592r-base.h"
  11
  12#include <linux/bitops.h>
  13#include <linux/module.h>
  14#include <linux/of.h>
  15#include <linux/spi/spi.h>
  16#include <linux/acpi.h>
  17
  18#define AD5592R_GPIO_READBACK_EN        BIT(10)
  19#define AD5592R_LDAC_READBACK_EN        BIT(6)
  20
  21static int ad5592r_spi_wnop_r16(struct ad5592r_state *st, __be16 *buf)
  22{
  23        struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
  24        struct spi_transfer t = {
  25                        .tx_buf = &st->spi_msg_nop,
  26                        .rx_buf = buf,
  27                        .len = 2
  28                };
  29
  30        st->spi_msg_nop = 0; /* NOP */
  31
  32        return spi_sync_transfer(spi, &t, 1);
  33}
  34
  35static int ad5592r_write_dac(struct ad5592r_state *st, unsigned chan, u16 value)
  36{
  37        struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
  38
  39        st->spi_msg = cpu_to_be16(BIT(15) | (chan << 12) | value);
  40
  41        return spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
  42}
  43
  44static int ad5592r_read_adc(struct ad5592r_state *st, unsigned chan, u16 *value)
  45{
  46        struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
  47        int ret;
  48
  49        st->spi_msg = cpu_to_be16((AD5592R_REG_ADC_SEQ << 11) | BIT(chan));
  50
  51        ret = spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
  52        if (ret)
  53                return ret;
  54
  55        /*
  56         * Invalid data:
  57         * See Figure 40. Single-Channel ADC Conversion Sequence
  58         */
  59        ret = ad5592r_spi_wnop_r16(st, &st->spi_msg);
  60        if (ret)
  61                return ret;
  62
  63        ret = ad5592r_spi_wnop_r16(st, &st->spi_msg);
  64        if (ret)
  65                return ret;
  66
  67        *value = be16_to_cpu(st->spi_msg);
  68
  69        return 0;
  70}
  71
  72static int ad5592r_reg_write(struct ad5592r_state *st, u8 reg, u16 value)
  73{
  74        struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
  75
  76        st->spi_msg = cpu_to_be16((reg << 11) | value);
  77
  78        return spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
  79}
  80
  81static int ad5592r_reg_read(struct ad5592r_state *st, u8 reg, u16 *value)
  82{
  83        struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
  84        int ret;
  85
  86        st->spi_msg = cpu_to_be16((AD5592R_REG_LDAC << 11) |
  87                                   AD5592R_LDAC_READBACK_EN | (reg << 2));
  88
  89        ret = spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
  90        if (ret)
  91                return ret;
  92
  93        ret = ad5592r_spi_wnop_r16(st, &st->spi_msg);
  94        if (ret)
  95                return ret;
  96
  97        *value = be16_to_cpu(st->spi_msg);
  98
  99        return 0;
 100}
 101
 102static int ad5593r_gpio_read(struct ad5592r_state *st, u8 *value)
 103{
 104        int ret;
 105
 106        ret = ad5592r_reg_write(st, AD5592R_REG_GPIO_IN_EN,
 107                                AD5592R_GPIO_READBACK_EN | st->gpio_in);
 108        if (ret)
 109                return ret;
 110
 111        ret = ad5592r_spi_wnop_r16(st, &st->spi_msg);
 112        if (ret)
 113                return ret;
 114
 115        *value = (u8) be16_to_cpu(st->spi_msg);
 116
 117        return 0;
 118}
 119
 120static const struct ad5592r_rw_ops ad5592r_rw_ops = {
 121        .write_dac = ad5592r_write_dac,
 122        .read_adc = ad5592r_read_adc,
 123        .reg_write = ad5592r_reg_write,
 124        .reg_read = ad5592r_reg_read,
 125        .gpio_read = ad5593r_gpio_read,
 126};
 127
 128static int ad5592r_spi_probe(struct spi_device *spi)
 129{
 130        const struct spi_device_id *id = spi_get_device_id(spi);
 131
 132        return ad5592r_probe(&spi->dev, id->name, &ad5592r_rw_ops);
 133}
 134
 135static int ad5592r_spi_remove(struct spi_device *spi)
 136{
 137        return ad5592r_remove(&spi->dev);
 138}
 139
 140static const struct spi_device_id ad5592r_spi_ids[] = {
 141        { .name = "ad5592r", },
 142        {}
 143};
 144MODULE_DEVICE_TABLE(spi, ad5592r_spi_ids);
 145
 146static const struct of_device_id ad5592r_of_match[] = {
 147        { .compatible = "adi,ad5592r", },
 148        {},
 149};
 150MODULE_DEVICE_TABLE(of, ad5592r_of_match);
 151
 152static const struct acpi_device_id ad5592r_acpi_match[] = {
 153        {"ADS5592", },
 154        { },
 155};
 156MODULE_DEVICE_TABLE(acpi, ad5592r_acpi_match);
 157
 158static struct spi_driver ad5592r_spi_driver = {
 159        .driver = {
 160                .name = "ad5592r",
 161                .of_match_table = of_match_ptr(ad5592r_of_match),
 162                .acpi_match_table = ACPI_PTR(ad5592r_acpi_match),
 163        },
 164        .probe = ad5592r_spi_probe,
 165        .remove = ad5592r_spi_remove,
 166        .id_table = ad5592r_spi_ids,
 167};
 168module_spi_driver(ad5592r_spi_driver);
 169
 170MODULE_AUTHOR("Paul Cercueil <paul.cercueil@analog.com>");
 171MODULE_DESCRIPTION("Analog Devices AD5592R multi-channel converters");
 172MODULE_LICENSE("GPL v2");
 173