Paul Cercueil | 56ca9db | 2016-04-05 09:46:19 +0200 | [diff] [blame] | 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 | |
| 17 | #define AD5592R_GPIO_READBACK_EN BIT(10) |
| 18 | #define AD5592R_LDAC_READBACK_EN BIT(6) |
| 19 | |
| 20 | static int ad5592r_spi_wnop_r16(struct ad5592r_state *st, u16 *buf) |
| 21 | { |
| 22 | struct spi_device *spi = container_of(st->dev, struct spi_device, dev); |
| 23 | struct spi_transfer t = { |
| 24 | .tx_buf = &st->spi_msg_nop, |
| 25 | .rx_buf = buf, |
| 26 | .len = 2 |
| 27 | }; |
| 28 | |
| 29 | st->spi_msg_nop = 0; /* NOP */ |
| 30 | |
| 31 | return spi_sync_transfer(spi, &t, 1); |
| 32 | } |
| 33 | |
| 34 | static int ad5592r_write_dac(struct ad5592r_state *st, unsigned chan, u16 value) |
| 35 | { |
| 36 | struct spi_device *spi = container_of(st->dev, struct spi_device, dev); |
| 37 | |
| 38 | st->spi_msg = cpu_to_be16(BIT(15) | (chan << 12) | value); |
| 39 | |
| 40 | return spi_write(spi, &st->spi_msg, sizeof(st->spi_msg)); |
| 41 | } |
| 42 | |
| 43 | static int ad5592r_read_adc(struct ad5592r_state *st, unsigned chan, u16 *value) |
| 44 | { |
| 45 | struct spi_device *spi = container_of(st->dev, struct spi_device, dev); |
| 46 | int ret; |
| 47 | |
| 48 | st->spi_msg = cpu_to_be16((AD5592R_REG_ADC_SEQ << 11) | BIT(chan)); |
| 49 | |
| 50 | ret = spi_write(spi, &st->spi_msg, sizeof(st->spi_msg)); |
| 51 | if (ret) |
| 52 | return ret; |
| 53 | |
| 54 | /* |
| 55 | * Invalid data: |
| 56 | * See Figure 40. Single-Channel ADC Conversion Sequence |
| 57 | */ |
| 58 | ret = ad5592r_spi_wnop_r16(st, &st->spi_msg); |
| 59 | if (ret) |
| 60 | return ret; |
| 61 | |
| 62 | ret = ad5592r_spi_wnop_r16(st, &st->spi_msg); |
| 63 | if (ret) |
| 64 | return ret; |
| 65 | |
| 66 | *value = be16_to_cpu(st->spi_msg); |
| 67 | |
| 68 | return 0; |
| 69 | } |
| 70 | |
| 71 | static int ad5592r_reg_write(struct ad5592r_state *st, u8 reg, u16 value) |
| 72 | { |
| 73 | struct spi_device *spi = container_of(st->dev, struct spi_device, dev); |
| 74 | |
| 75 | st->spi_msg = cpu_to_be16((reg << 11) | value); |
| 76 | |
| 77 | return spi_write(spi, &st->spi_msg, sizeof(st->spi_msg)); |
| 78 | } |
| 79 | |
| 80 | static int ad5592r_reg_read(struct ad5592r_state *st, u8 reg, u16 *value) |
| 81 | { |
| 82 | struct spi_device *spi = container_of(st->dev, struct spi_device, dev); |
| 83 | int ret; |
| 84 | |
| 85 | st->spi_msg = cpu_to_be16((AD5592R_REG_LDAC << 11) | |
| 86 | AD5592R_LDAC_READBACK_EN | (reg << 2)); |
| 87 | |
| 88 | ret = spi_write(spi, &st->spi_msg, sizeof(st->spi_msg)); |
| 89 | if (ret) |
| 90 | return ret; |
| 91 | |
| 92 | ret = ad5592r_spi_wnop_r16(st, &st->spi_msg); |
| 93 | if (ret) |
| 94 | return ret; |
| 95 | |
| 96 | *value = be16_to_cpu(st->spi_msg); |
| 97 | |
| 98 | return 0; |
| 99 | } |
| 100 | |
| 101 | static int ad5593r_gpio_read(struct ad5592r_state *st, u8 *value) |
| 102 | { |
| 103 | int ret; |
| 104 | |
| 105 | ret = ad5592r_reg_write(st, AD5592R_REG_GPIO_IN_EN, |
| 106 | AD5592R_GPIO_READBACK_EN | st->gpio_in); |
| 107 | if (ret) |
| 108 | return ret; |
| 109 | |
| 110 | ret = ad5592r_spi_wnop_r16(st, &st->spi_msg); |
| 111 | if (ret) |
| 112 | return ret; |
| 113 | |
| 114 | *value = (u8) be16_to_cpu(st->spi_msg); |
| 115 | |
| 116 | return 0; |
| 117 | } |
| 118 | |
| 119 | static const struct ad5592r_rw_ops ad5592r_rw_ops = { |
| 120 | .write_dac = ad5592r_write_dac, |
| 121 | .read_adc = ad5592r_read_adc, |
| 122 | .reg_write = ad5592r_reg_write, |
| 123 | .reg_read = ad5592r_reg_read, |
| 124 | .gpio_read = ad5593r_gpio_read, |
| 125 | }; |
| 126 | |
| 127 | static int ad5592r_spi_probe(struct spi_device *spi) |
| 128 | { |
| 129 | const struct spi_device_id *id = spi_get_device_id(spi); |
| 130 | |
| 131 | return ad5592r_probe(&spi->dev, id->name, &ad5592r_rw_ops); |
| 132 | } |
| 133 | |
| 134 | static int ad5592r_spi_remove(struct spi_device *spi) |
| 135 | { |
| 136 | return ad5592r_remove(&spi->dev); |
| 137 | } |
| 138 | |
| 139 | static const struct spi_device_id ad5592r_spi_ids[] = { |
| 140 | { .name = "ad5592r", }, |
| 141 | {} |
| 142 | }; |
| 143 | MODULE_DEVICE_TABLE(spi, ad5592r_spi_ids); |
| 144 | |
| 145 | static const struct of_device_id ad5592r_of_match[] = { |
| 146 | { .compatible = "adi,ad5592r", }, |
| 147 | {}, |
| 148 | }; |
| 149 | MODULE_DEVICE_TABLE(of, ad5592r_of_match); |
| 150 | |
| 151 | static struct spi_driver ad5592r_spi_driver = { |
| 152 | .driver = { |
| 153 | .name = "ad5592r", |
| 154 | .of_match_table = of_match_ptr(ad5592r_of_match), |
| 155 | }, |
| 156 | .probe = ad5592r_spi_probe, |
| 157 | .remove = ad5592r_spi_remove, |
| 158 | .id_table = ad5592r_spi_ids, |
| 159 | }; |
| 160 | module_spi_driver(ad5592r_spi_driver); |
| 161 | |
| 162 | MODULE_AUTHOR("Paul Cercueil <paul.cercueil@analog.com>"); |
| 163 | MODULE_DESCRIPTION("Analog Devices AD5592R multi-channel converters"); |
| 164 | MODULE_LICENSE("GPL v2"); |