drivers/iio/dac/ad5592r.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * AD5592R Digital <-> Analog converters driver
   4  *
   5  * Copyright 2015-2016 Analog Devices Inc.
   6  * Author: Paul Cercueil <paul.cercueil@analog.com>
   7  */
   8
   9 #include "ad5592r-base.h"
  10
  11 #include <linux/bitops.h>
  12 #include <linux/module.h>
  13 #include <linux/mod_devicetable.h>
  14 #include <linux/spi/spi.h>
  15
  16 #define AD5592R_GPIO_READBACK_EN        BIT(10)
  17 #define AD5592R_LDAC_READBACK_EN        BIT(6)
  18
  19 static int ad5592r_spi_wnop_r16(struct ad5592r_state *st, __be16 *buf)
  20 {
  21         struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
  22         struct spi_transfer t = {
  23                         .tx_buf = &st->spi_msg_nop,
  24                         .rx_buf = buf,
  25                         .len = 2
  26                 };
  27
  28         st->spi_msg_nop = 0; /* NOP */
  29
  30         return spi_sync_transfer(spi, &t, 1);
  31 }
  32
  33 static int ad5592r_write_dac(struct ad5592r_state *st, unsigned chan, u16 value)
  34 {
  35         struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
  36
  37         st->spi_msg = cpu_to_be16(BIT(15) | (chan << 12) | value);
  38
  39         return spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
  40 }
  41
  42 static int ad5592r_read_adc(struct ad5592r_state *st, unsigned chan, u16 *value)
  43 {
  44         struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
  45         int ret;
  46
  47         st->spi_msg = cpu_to_be16((AD5592R_REG_ADC_SEQ << 11) | BIT(chan));
  48
  49         ret = spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
  50         if (ret)
  51                 return ret;
  52
  53         /*
  54          * Invalid data:
  55          * See Figure 40. Single-Channel ADC Conversion Sequence
  56          */
  57         ret = ad5592r_spi_wnop_r16(st, &st->spi_msg);
  58         if (ret)
  59                 return ret;
  60
  61         ret = ad5592r_spi_wnop_r16(st, &st->spi_msg);
  62         if (ret)
  63                 return ret;
  64
  65         *value = be16_to_cpu(st->spi_msg);
  66
  67         return 0;
  68 }
  69
  70 static int ad5592r_reg_write(struct ad5592r_state *st, u8 reg, u16 value)
  71 {
  72         struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
  73
  74         st->spi_msg = cpu_to_be16((reg << 11) | value);
  75
  76         return spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
  77 }
  78
  79 static int ad5592r_reg_read(struct ad5592r_state *st, u8 reg, u16 *value)
  80 {
  81         struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
  82         int ret;
  83
  84         st->spi_msg = cpu_to_be16((AD5592R_REG_LDAC << 11) |
  85                                    AD5592R_LDAC_READBACK_EN | (reg << 2));
  86
  87         ret = spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
  88         if (ret)
  89                 return ret;
  90
  91         ret = ad5592r_spi_wnop_r16(st, &st->spi_msg);
  92         if (ret)
  93                 return ret;
  94
  95         *value = be16_to_cpu(st->spi_msg);
  96
  97         return 0;
  98 }
  99
 100 static int ad5592r_gpio_read(struct ad5592r_state *st, u8 *value)
 101 {
 102         int ret;
 103
 104         ret = ad5592r_reg_write(st, AD5592R_REG_GPIO_IN_EN,
 105                                 AD5592R_GPIO_READBACK_EN | st->gpio_in);
 106         if (ret)
 107                 return ret;
 108
 109         ret = ad5592r_spi_wnop_r16(st, &st->spi_msg);
 110         if (ret)
 111                 return ret;
 112
 113         *value = (u8) be16_to_cpu(st->spi_msg);
 114
 115         return 0;
 116 }
 117
 118 static const struct ad5592r_rw_ops ad5592r_rw_ops = {
 119         .write_dac = ad5592r_write_dac,
 120         .read_adc = ad5592r_read_adc,
 121         .reg_write = ad5592r_reg_write,
 122         .reg_read = ad5592r_reg_read,
 123         .gpio_read = ad5592r_gpio_read,
 124 };
 125
 126 static int ad5592r_spi_probe(struct spi_device *spi)
 127 {
 128         const struct spi_device_id *id = spi_get_device_id(spi);
 129
 130         return ad5592r_probe(&spi->dev, id->name, &ad5592r_rw_ops);
 131 }
 132
 133 static int ad5592r_spi_remove(struct spi_device *spi)
 134 {
 135         return ad5592r_remove(&spi->dev);
 136 }
 137
 138 static const struct spi_device_id ad5592r_spi_ids[] = {
 139         { .name = "ad5592r", },
 140         {}
 141 };
 142 MODULE_DEVICE_TABLE(spi, ad5592r_spi_ids);
 143
 144 static const struct of_device_id ad5592r_of_match[] = {
 145         { .compatible = "adi,ad5592r", },
 146         {},
 147 };
 148 MODULE_DEVICE_TABLE(of, ad5592r_of_match);
 149
 150 static const struct acpi_device_id ad5592r_acpi_match[] = {
 151         {"ADS5592", },
 152         { },
 153 };
 154 MODULE_DEVICE_TABLE(acpi, ad5592r_acpi_match);
 155
 156 static struct spi_driver ad5592r_spi_driver = {
 157         .driver = {
 158                 .name = "ad5592r",
 159                 .of_match_table = ad5592r_of_match,
 160                 .acpi_match_table = ad5592r_acpi_match,
 161         },
 162         .probe = ad5592r_spi_probe,
 163         .remove = ad5592r_spi_remove,
 164         .id_table = ad5592r_spi_ids,
 165 };
 166 module_spi_driver(ad5592r_spi_driver);
 167
 168 MODULE_AUTHOR("Paul Cercueil <paul.cercueil@analog.com>");
 169 MODULE_DESCRIPTION("Analog Devices AD5592R multi-channel converters");
 170 MODULE_LICENSE("GPL v2");