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
ad5686_spi_write(struct ad5686_state * st,u8 cmd,u8 addr,u16 val)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
ad5686_spi_sync(struct ad5686_state * st)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
ad5686_spi_read(struct ad5686_state * st,u8 addr)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
ad5686_spi_probe(struct spi_device * spi)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