1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * SPI driver for AD5686 and similar Digital to Analog Converters 4 * 5 * Copyright 2018 Analog Devices Inc. 6 */ 7 8 #include <linux/array_size.h> 9 #include <linux/bitfield.h> 10 #include <linux/errno.h> 11 #include <linux/module.h> 12 #include <linux/overflow.h> 13 #include <linux/spi/spi.h> 14 15 #include <asm/byteorder.h> 16 17 #include "ad5686.h" 18 19 /** 20 * struct ad5686_spi_data - SPI bus specific data 21 * @msg: SPI message used for transfers 22 * @size: number of transfers currently in the message 23 * @capacity: maximum number of transfers that can be added to the message 24 * @xfers: array of SPI transfers, allocated with the provided capacity 25 */ 26 struct ad5686_spi_data { 27 struct spi_message msg; 28 unsigned int size; 29 unsigned int capacity; 30 struct spi_transfer xfers[] __counted_by(capacity); 31 }; 32 33 static int ad5686_spi_write(struct ad5686_state *st, 34 u8 cmd, u8 addr, u16 val) 35 { 36 struct ad5686_spi_data *bus_data = st->bus_data; 37 struct spi_transfer *xfer; 38 39 if (bus_data->size >= bus_data->capacity) 40 return -E2BIG; 41 42 /* 43 * This function stores spi transfers to a spi message to be sent over 44 * the bus when sync() op is called. If there are already transfers in 45 * the spi message, set the cs_change flag on the last transfer to 46 * ensure that the chip select is deasserted between transfers. If this 47 * is the first transfer, initialize the spi message. Later on, the 48 * current transfer is added to the message with spi_message_add_tail(). 49 */ 50 if (bus_data->size) 51 bus_data->xfers[bus_data->size - 1].cs_change = 1; 52 else 53 spi_message_init(&bus_data->msg); 54 55 xfer = &bus_data->xfers[bus_data->size]; 56 auto buf = &st->data[bus_data->size]; 57 switch (st->chip_info->regmap_type) { 58 case AD5310_REGMAP: 59 buf->d16 = cpu_to_be16(FIELD_PREP(AD5310_CMD_MSK, cmd) | 60 FIELD_PREP(AD5310_DATA_MSK, val)); 61 *xfer = (struct spi_transfer) { 62 .tx_buf = &buf->d16, 63 .len = sizeof(buf->d16), 64 }; 65 break; 66 case AD5683_REGMAP: 67 buf->d32 = cpu_to_be32(FIELD_PREP(AD5686_CMD_MSK, cmd) | 68 FIELD_PREP(AD5683_DATA_MSK, val)); 69 *xfer = (struct spi_transfer) { 70 .tx_buf = &buf->d8[1], 71 .len = sizeof(buf->d8) - 1, 72 }; 73 break; 74 case AD5686_REGMAP: 75 buf->d32 = cpu_to_be32(FIELD_PREP(AD5686_CMD_MSK, cmd) | 76 FIELD_PREP(AD5686_ADDR_MSK, addr) | 77 FIELD_PREP(AD5686_DATA_MSK, val)); 78 *xfer = (struct spi_transfer) { 79 .tx_buf = &buf->d8[1], 80 .len = sizeof(buf->d8) - 1, 81 }; 82 break; 83 default: 84 return -EINVAL; 85 } 86 87 spi_message_add_tail(xfer, &bus_data->msg); 88 bus_data->size++; 89 90 return 0; 91 } 92 93 static int ad5686_spi_sync(struct ad5686_state *st) 94 { 95 struct spi_device *spi = to_spi_device(st->dev); 96 struct ad5686_spi_data *bus_data = st->bus_data; 97 98 bus_data->size = 0; /* always reset, even on sync failure */ 99 return spi_sync(spi, &bus_data->msg); 100 } 101 102 static int ad5686_spi_read(struct ad5686_state *st, u8 addr) 103 { 104 struct spi_device *spi = to_spi_device(st->dev); 105 struct ad5686_spi_data *bus_data = st->bus_data; 106 struct spi_transfer *xfer = &bus_data->xfers[0]; 107 u8 cmd = 0; 108 int ret; 109 110 switch (st->chip_info->regmap_type) { 111 case AD5310_REGMAP: 112 return -ENOTSUPP; 113 case AD5683_REGMAP: 114 cmd = AD5686_CMD_READBACK_ENABLE_V2; 115 break; 116 case AD5686_REGMAP: 117 cmd = AD5686_CMD_READBACK_ENABLE; 118 break; 119 default: 120 return -EINVAL; 121 } 122 123 st->data[0].d32 = cpu_to_be32(FIELD_PREP(AD5686_CMD_MSK, cmd) | 124 FIELD_PREP(AD5686_ADDR_MSK, addr)); 125 st->data[1].d32 = cpu_to_be32(FIELD_PREP(AD5686_CMD_MSK, AD5686_CMD_NOOP)); 126 127 xfer[0] = (struct spi_transfer) { 128 .tx_buf = &st->data[0].d8[1], 129 .len = sizeof(st->data[0].d8) - 1, 130 .cs_change = 1, 131 }; 132 xfer[1] = (struct spi_transfer) { 133 .tx_buf = &st->data[1].d8[1], 134 .rx_buf = &st->data[2].d8[1], 135 .len = sizeof(st->data[1].d8) - 1, 136 }; 137 138 spi_message_init_with_transfers(&bus_data->msg, xfer, 2); 139 140 ret = spi_sync(spi, &bus_data->msg); 141 if (ret) 142 return ret; 143 144 return be32_to_cpu(st->data[2].d32); 145 } 146 147 static const struct ad5686_bus_ops ad5686_spi_ops = { 148 .write = ad5686_spi_write, 149 .read = ad5686_spi_read, 150 .sync = ad5686_spi_sync, 151 }; 152 153 static int ad5686_spi_probe(struct spi_device *spi) 154 { 155 const struct ad5686_chip_info *info; 156 struct ad5686_spi_data *bus_data; 157 struct device *dev = &spi->dev; 158 unsigned int capacity; 159 160 info = spi_get_device_match_data(spi); 161 if (!info) 162 return -ENODATA; 163 164 /* read operation requires at least 2 transfers */ 165 capacity = max(info->num_channels, 2); 166 bus_data = devm_kzalloc(dev, struct_size(bus_data, xfers, capacity), 167 GFP_KERNEL); 168 if (!bus_data) 169 return -ENOMEM; 170 171 bus_data->capacity = capacity; 172 173 return ad5686_probe(dev, info, spi->modalias, &ad5686_spi_ops, bus_data); 174 } 175 176 static const struct spi_device_id ad5686_spi_id[] = { 177 { .name = "ad5310r", .driver_data = (kernel_ulong_t)&ad5310r_chip_info }, 178 { .name = "ad5313r", .driver_data = (kernel_ulong_t)&ad5338r_chip_info }, 179 { .name = "ad5317r", .driver_data = (kernel_ulong_t)&ad5317r_chip_info }, 180 { .name = "ad5672r", .driver_data = (kernel_ulong_t)&ad5672r_chip_info }, 181 { .name = "ad5674", .driver_data = (kernel_ulong_t)&ad5674_chip_info }, 182 { .name = "ad5674r", .driver_data = (kernel_ulong_t)&ad5674r_chip_info }, 183 { .name = "ad5676", .driver_data = (kernel_ulong_t)&ad5676_chip_info }, 184 { .name = "ad5676r", .driver_data = (kernel_ulong_t)&ad5676r_chip_info }, 185 { .name = "ad5679", .driver_data = (kernel_ulong_t)&ad5679_chip_info }, 186 { .name = "ad5679r", .driver_data = (kernel_ulong_t)&ad5679r_chip_info }, 187 { .name = "ad5681r", .driver_data = (kernel_ulong_t)&ad5681r_chip_info }, 188 { .name = "ad5682r", .driver_data = (kernel_ulong_t)&ad5682r_chip_info }, 189 { .name = "ad5683", .driver_data = (kernel_ulong_t)&ad5683_chip_info }, 190 { .name = "ad5683r", .driver_data = (kernel_ulong_t)&ad5683r_chip_info }, 191 { .name = "ad5684", .driver_data = (kernel_ulong_t)&ad5684_chip_info }, 192 { .name = "ad5684r", .driver_data = (kernel_ulong_t)&ad5684r_chip_info }, 193 { .name = "ad5685", .driver_data = (kernel_ulong_t)&ad5685r_chip_info }, /* nonexistent */ 194 { .name = "ad5685r", .driver_data = (kernel_ulong_t)&ad5685r_chip_info }, 195 { .name = "ad5686", .driver_data = (kernel_ulong_t)&ad5686_chip_info }, 196 { .name = "ad5686r", .driver_data = (kernel_ulong_t)&ad5686r_chip_info }, 197 { .name = "ad5687", .driver_data = (kernel_ulong_t)&ad5687_chip_info }, 198 { .name = "ad5687r", .driver_data = (kernel_ulong_t)&ad5687r_chip_info }, 199 { .name = "ad5689", .driver_data = (kernel_ulong_t)&ad5689_chip_info }, 200 { .name = "ad5689r", .driver_data = (kernel_ulong_t)&ad5689r_chip_info }, 201 { } 202 }; 203 MODULE_DEVICE_TABLE(spi, ad5686_spi_id); 204 205 static const struct of_device_id ad5686_of_match[] = { 206 { .compatible = "adi,ad5310r", .data = &ad5310r_chip_info }, 207 { .compatible = "adi,ad5313r", .data = &ad5338r_chip_info }, 208 { .compatible = "adi,ad5317r", .data = &ad5317r_chip_info }, 209 { .compatible = "adi,ad5672r", .data = &ad5672r_chip_info }, 210 { .compatible = "adi,ad5674", .data = &ad5674_chip_info }, 211 { .compatible = "adi,ad5674r", .data = &ad5674r_chip_info }, 212 { .compatible = "adi,ad5676", .data = &ad5676_chip_info }, 213 { .compatible = "adi,ad5676r", .data = &ad5676r_chip_info }, 214 { .compatible = "adi,ad5679", .data = &ad5679_chip_info }, 215 { .compatible = "adi,ad5679r", .data = &ad5679r_chip_info }, 216 { .compatible = "adi,ad5681r", .data = &ad5681r_chip_info }, 217 { .compatible = "adi,ad5682r", .data = &ad5682r_chip_info }, 218 { .compatible = "adi,ad5683", .data = &ad5683_chip_info }, 219 { .compatible = "adi,ad5683r", .data = &ad5683r_chip_info }, 220 { .compatible = "adi,ad5684", .data = &ad5684_chip_info }, 221 { .compatible = "adi,ad5684r", .data = &ad5684r_chip_info }, 222 { .compatible = "adi,ad5685r", .data = &ad5685r_chip_info }, 223 { .compatible = "adi,ad5686", .data = &ad5686_chip_info }, 224 { .compatible = "adi,ad5686r", .data = &ad5686r_chip_info }, 225 { .compatible = "adi,ad5687", .data = &ad5687_chip_info }, 226 { .compatible = "adi,ad5687r", .data = &ad5687r_chip_info }, 227 { .compatible = "adi,ad5689", .data = &ad5689_chip_info }, 228 { .compatible = "adi,ad5689r", .data = &ad5689r_chip_info }, 229 { } 230 }; 231 MODULE_DEVICE_TABLE(of, ad5686_of_match); 232 233 static struct spi_driver ad5686_spi_driver = { 234 .driver = { 235 .name = "ad5686", 236 .of_match_table = ad5686_of_match, 237 }, 238 .probe = ad5686_spi_probe, 239 .id_table = ad5686_spi_id, 240 }; 241 242 module_spi_driver(ad5686_spi_driver); 243 244 MODULE_AUTHOR("Stefan Popa <stefan.popa@analog.com>"); 245 MODULE_DESCRIPTION("Analog Devices AD5686 and similar multi-channel DACs"); 246 MODULE_LICENSE("GPL v2"); 247 MODULE_IMPORT_NS("IIO_AD5686"); 248