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80503b23 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
b3165900 LPC |
2 | /* |
3 | * Analog Devices AD-FMCOMMS1-EBZ board I2C-SPI bridge driver | |
4 | * | |
5 | * Copyright 2012 Analog Devices Inc. | |
6 | * Author: Lars-Peter Clausen <lars@metafoo.de> | |
b3165900 LPC |
7 | */ |
8 | ||
9 | #include <linux/kernel.h> | |
b3165900 LPC |
10 | #include <linux/module.h> |
11 | #include <linux/delay.h> | |
12 | #include <linux/i2c.h> | |
13 | #include <linux/spi/spi.h> | |
14 | #include <asm/unaligned.h> | |
15 | ||
16 | #define SPI_XCOMM_SETTINGS_LEN_OFFSET 10 | |
17 | #define SPI_XCOMM_SETTINGS_3WIRE BIT(6) | |
18 | #define SPI_XCOMM_SETTINGS_CS_HIGH BIT(5) | |
19 | #define SPI_XCOMM_SETTINGS_SAMPLE_END BIT(4) | |
20 | #define SPI_XCOMM_SETTINGS_CPHA BIT(3) | |
21 | #define SPI_XCOMM_SETTINGS_CPOL BIT(2) | |
22 | #define SPI_XCOMM_SETTINGS_CLOCK_DIV_MASK 0x3 | |
23 | #define SPI_XCOMM_SETTINGS_CLOCK_DIV_64 0x2 | |
24 | #define SPI_XCOMM_SETTINGS_CLOCK_DIV_16 0x1 | |
25 | #define SPI_XCOMM_SETTINGS_CLOCK_DIV_4 0x0 | |
26 | ||
27 | #define SPI_XCOMM_CMD_UPDATE_CONFIG 0x03 | |
28 | #define SPI_XCOMM_CMD_WRITE 0x04 | |
29 | ||
30 | #define SPI_XCOMM_CLOCK 48000000 | |
31 | ||
32 | struct spi_xcomm { | |
33 | struct i2c_client *i2c; | |
34 | ||
35 | uint16_t settings; | |
36 | uint16_t chipselect; | |
37 | ||
38 | unsigned int current_speed; | |
39 | ||
40 | uint8_t buf[63]; | |
41 | }; | |
42 | ||
43 | static int spi_xcomm_sync_config(struct spi_xcomm *spi_xcomm, unsigned int len) | |
44 | { | |
45 | uint16_t settings; | |
46 | uint8_t *buf = spi_xcomm->buf; | |
47 | ||
48 | settings = spi_xcomm->settings; | |
49 | settings |= len << SPI_XCOMM_SETTINGS_LEN_OFFSET; | |
50 | ||
51 | buf[0] = SPI_XCOMM_CMD_UPDATE_CONFIG; | |
52 | put_unaligned_be16(settings, &buf[1]); | |
53 | put_unaligned_be16(spi_xcomm->chipselect, &buf[3]); | |
54 | ||
55 | return i2c_master_send(spi_xcomm->i2c, buf, 5); | |
56 | } | |
57 | ||
58 | static void spi_xcomm_chipselect(struct spi_xcomm *spi_xcomm, | |
59 | struct spi_device *spi, int is_active) | |
60 | { | |
61 | unsigned long cs = spi->chip_select; | |
62 | uint16_t chipselect = spi_xcomm->chipselect; | |
63 | ||
64 | if (is_active) | |
65 | chipselect |= BIT(cs); | |
66 | else | |
67 | chipselect &= ~BIT(cs); | |
68 | ||
69 | spi_xcomm->chipselect = chipselect; | |
70 | } | |
71 | ||
72 | static int spi_xcomm_setup_transfer(struct spi_xcomm *spi_xcomm, | |
73 | struct spi_device *spi, struct spi_transfer *t, unsigned int *settings) | |
74 | { | |
24778be2 | 75 | if (t->len > 62) |
b3165900 LPC |
76 | return -EINVAL; |
77 | ||
af348519 AL |
78 | if (t->speed_hz != spi_xcomm->current_speed) { |
79 | unsigned int divider; | |
b3165900 | 80 | |
af348519 | 81 | divider = DIV_ROUND_UP(SPI_XCOMM_CLOCK, t->speed_hz); |
b3165900 LPC |
82 | if (divider >= 64) |
83 | *settings |= SPI_XCOMM_SETTINGS_CLOCK_DIV_64; | |
84 | else if (divider >= 16) | |
85 | *settings |= SPI_XCOMM_SETTINGS_CLOCK_DIV_16; | |
86 | else | |
87 | *settings |= SPI_XCOMM_SETTINGS_CLOCK_DIV_4; | |
88 | ||
af348519 | 89 | spi_xcomm->current_speed = t->speed_hz; |
b3165900 LPC |
90 | } |
91 | ||
92 | if (spi->mode & SPI_CPOL) | |
93 | *settings |= SPI_XCOMM_SETTINGS_CPOL; | |
94 | else | |
95 | *settings &= ~SPI_XCOMM_SETTINGS_CPOL; | |
96 | ||
97 | if (spi->mode & SPI_CPHA) | |
98 | *settings &= ~SPI_XCOMM_SETTINGS_CPHA; | |
99 | else | |
100 | *settings |= SPI_XCOMM_SETTINGS_CPHA; | |
101 | ||
102 | if (spi->mode & SPI_3WIRE) | |
103 | *settings |= SPI_XCOMM_SETTINGS_3WIRE; | |
104 | else | |
105 | *settings &= ~SPI_XCOMM_SETTINGS_3WIRE; | |
106 | ||
107 | return 0; | |
108 | } | |
109 | ||
110 | static int spi_xcomm_txrx_bufs(struct spi_xcomm *spi_xcomm, | |
111 | struct spi_device *spi, struct spi_transfer *t) | |
112 | { | |
113 | int ret; | |
114 | ||
115 | if (t->tx_buf) { | |
116 | spi_xcomm->buf[0] = SPI_XCOMM_CMD_WRITE; | |
117 | memcpy(spi_xcomm->buf + 1, t->tx_buf, t->len); | |
118 | ||
119 | ret = i2c_master_send(spi_xcomm->i2c, spi_xcomm->buf, t->len + 1); | |
120 | if (ret < 0) | |
121 | return ret; | |
122 | else if (ret != t->len + 1) | |
123 | return -EIO; | |
124 | } else if (t->rx_buf) { | |
125 | ret = i2c_master_recv(spi_xcomm->i2c, t->rx_buf, t->len); | |
126 | if (ret < 0) | |
127 | return ret; | |
128 | else if (ret != t->len) | |
129 | return -EIO; | |
130 | } | |
131 | ||
132 | return t->len; | |
133 | } | |
134 | ||
135 | static int spi_xcomm_transfer_one(struct spi_master *master, | |
136 | struct spi_message *msg) | |
137 | { | |
138 | struct spi_xcomm *spi_xcomm = spi_master_get_devdata(master); | |
139 | unsigned int settings = spi_xcomm->settings; | |
140 | struct spi_device *spi = msg->spi; | |
141 | unsigned cs_change = 0; | |
142 | struct spi_transfer *t; | |
143 | bool is_first = true; | |
144 | int status = 0; | |
145 | bool is_last; | |
146 | ||
b3165900 LPC |
147 | spi_xcomm_chipselect(spi_xcomm, spi, true); |
148 | ||
149 | list_for_each_entry(t, &msg->transfers, transfer_list) { | |
150 | ||
151 | if (!t->tx_buf && !t->rx_buf && t->len) { | |
152 | status = -EINVAL; | |
153 | break; | |
154 | } | |
155 | ||
156 | status = spi_xcomm_setup_transfer(spi_xcomm, spi, t, &settings); | |
157 | if (status < 0) | |
158 | break; | |
159 | ||
160 | is_last = list_is_last(&t->transfer_list, &msg->transfers); | |
161 | cs_change = t->cs_change; | |
162 | ||
163 | if (cs_change ^ is_last) | |
164 | settings |= BIT(5); | |
165 | else | |
166 | settings &= ~BIT(5); | |
167 | ||
168 | if (t->rx_buf) { | |
169 | spi_xcomm->settings = settings; | |
170 | status = spi_xcomm_sync_config(spi_xcomm, t->len); | |
171 | if (status < 0) | |
172 | break; | |
173 | } else if (settings != spi_xcomm->settings || is_first) { | |
174 | spi_xcomm->settings = settings; | |
175 | status = spi_xcomm_sync_config(spi_xcomm, 0); | |
176 | if (status < 0) | |
177 | break; | |
178 | } | |
179 | ||
180 | if (t->len) { | |
181 | status = spi_xcomm_txrx_bufs(spi_xcomm, spi, t); | |
182 | ||
183 | if (status < 0) | |
184 | break; | |
185 | ||
186 | if (status > 0) | |
187 | msg->actual_length += status; | |
188 | } | |
189 | status = 0; | |
190 | ||
e74dc5c7 | 191 | spi_transfer_delay_exec(t); |
b3165900 LPC |
192 | |
193 | is_first = false; | |
194 | } | |
195 | ||
196 | if (status != 0 || !cs_change) | |
197 | spi_xcomm_chipselect(spi_xcomm, spi, false); | |
198 | ||
199 | msg->status = status; | |
200 | spi_finalize_current_message(master); | |
201 | ||
202 | return status; | |
203 | } | |
204 | ||
fd4a319b | 205 | static int spi_xcomm_probe(struct i2c_client *i2c, |
b3165900 LPC |
206 | const struct i2c_device_id *id) |
207 | { | |
208 | struct spi_xcomm *spi_xcomm; | |
209 | struct spi_master *master; | |
210 | int ret; | |
211 | ||
212 | master = spi_alloc_master(&i2c->dev, sizeof(*spi_xcomm)); | |
213 | if (!master) | |
214 | return -ENOMEM; | |
215 | ||
216 | spi_xcomm = spi_master_get_devdata(master); | |
217 | spi_xcomm->i2c = i2c; | |
218 | ||
219 | master->num_chipselect = 16; | |
220 | master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_3WIRE; | |
24778be2 | 221 | master->bits_per_word_mask = SPI_BPW_MASK(8); |
b3165900 | 222 | master->flags = SPI_MASTER_HALF_DUPLEX; |
b3165900 LPC |
223 | master->transfer_one_message = spi_xcomm_transfer_one; |
224 | master->dev.of_node = i2c->dev.of_node; | |
225 | i2c_set_clientdata(i2c, master); | |
226 | ||
4cc16085 | 227 | ret = devm_spi_register_master(&i2c->dev, master); |
b3165900 LPC |
228 | if (ret < 0) |
229 | spi_master_put(master); | |
230 | ||
231 | return ret; | |
232 | } | |
233 | ||
b3165900 LPC |
234 | static const struct i2c_device_id spi_xcomm_ids[] = { |
235 | { "spi-xcomm" }, | |
236 | { }, | |
237 | }; | |
98c7863c | 238 | MODULE_DEVICE_TABLE(i2c, spi_xcomm_ids); |
b3165900 LPC |
239 | |
240 | static struct i2c_driver spi_xcomm_driver = { | |
241 | .driver = { | |
242 | .name = "spi-xcomm", | |
b3165900 LPC |
243 | }, |
244 | .id_table = spi_xcomm_ids, | |
245 | .probe = spi_xcomm_probe, | |
b3165900 LPC |
246 | }; |
247 | module_i2c_driver(spi_xcomm_driver); | |
248 | ||
249 | MODULE_LICENSE("GPL"); | |
250 | MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); | |
251 | MODULE_DESCRIPTION("Analog Devices AD-FMCOMMS1-EBZ board I2C-SPI bridge driver"); |