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, __be16 *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"); 165