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
  21 static 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
  35 static 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
  44 static 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
  72 static 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
  81 static 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
 102 static 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
 120 static 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
 128 static 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
 135 static int ad5592r_spi_remove(struct spi_device *spi)
 136 {
 137         return ad5592r_remove(&spi->dev);
 138 }
 139
 140 static const struct spi_device_id ad5592r_spi_ids[] = {
 141         { .name = "ad5592r", },
 142         {}
 143 };
 144 MODULE_DEVICE_TABLE(spi, ad5592r_spi_ids);
 145
 146 static const struct of_device_id ad5592r_of_match[] = {
 147         { .compatible = "adi,ad5592r", },
 148         {},
 149 };
 150 MODULE_DEVICE_TABLE(of, ad5592r_of_match);
 151
 152 static const struct acpi_device_id ad5592r_acpi_match[] = {
 153         {"ADS5592", },
 154         { },
 155 };
 156 MODULE_DEVICE_TABLE(acpi, ad5592r_acpi_match);
 157
 158 static 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 };
 168 module_spi_driver(ad5592r_spi_driver);
 169
 170 MODULE_AUTHOR("Paul Cercueil <paul.cercueil@analog.com>");
 171 MODULE_DESCRIPTION("Analog Devices AD5592R multi-channel converters");
 172 MODULE_LICENSE("GPL v2");