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1// SPDX-License-Identifier: GPL-2.0-or-later
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>
7 */
8
9#include <linux/kernel.h>
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
32struct 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
43static 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
58static 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
72static int spi_xcomm_setup_transfer(struct spi_xcomm *spi_xcomm,
73 struct spi_device *spi, struct spi_transfer *t, unsigned int *settings)
74{
75 if (t->len > 62)
76 return -EINVAL;
77
78 if (t->speed_hz != spi_xcomm->current_speed) {
79 unsigned int divider;
80
81 divider = DIV_ROUND_UP(SPI_XCOMM_CLOCK, t->speed_hz);
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
89 spi_xcomm->current_speed = t->speed_hz;
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
110static 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
135static 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
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
191 spi_transfer_delay_exec(t);
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
205static int spi_xcomm_probe(struct i2c_client *i2c)
206{
207 struct spi_xcomm *spi_xcomm;
208 struct spi_master *master;
209 int ret;
210
211 master = spi_alloc_master(&i2c->dev, sizeof(*spi_xcomm));
212 if (!master)
213 return -ENOMEM;
214
215 spi_xcomm = spi_master_get_devdata(master);
216 spi_xcomm->i2c = i2c;
217
218 master->num_chipselect = 16;
219 master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_3WIRE;
220 master->bits_per_word_mask = SPI_BPW_MASK(8);
221 master->flags = SPI_MASTER_HALF_DUPLEX;
222 master->transfer_one_message = spi_xcomm_transfer_one;
223 master->dev.of_node = i2c->dev.of_node;
224 i2c_set_clientdata(i2c, master);
225
226 ret = devm_spi_register_master(&i2c->dev, master);
227 if (ret < 0)
228 spi_master_put(master);
229
230 return ret;
231}
232
233static const struct i2c_device_id spi_xcomm_ids[] = {
234 { "spi-xcomm" },
235 { },
236};
237MODULE_DEVICE_TABLE(i2c, spi_xcomm_ids);
238
239static struct i2c_driver spi_xcomm_driver = {
240 .driver = {
241 .name = "spi-xcomm",
242 },
243 .id_table = spi_xcomm_ids,
244 .probe_new = spi_xcomm_probe,
245};
246module_i2c_driver(spi_xcomm_driver);
247
248MODULE_LICENSE("GPL");
249MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
250MODULE_DESCRIPTION("Analog Devices AD-FMCOMMS1-EBZ board I2C-SPI bridge driver");
1// SPDX-License-Identifier: GPL-2.0-or-later
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>
7 */
8
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/delay.h>
12#include <linux/i2c.h>
13#include <linux/gpio/driver.h>
14#include <linux/spi/spi.h>
15#include <linux/unaligned.h>
16
17#define SPI_XCOMM_SETTINGS_LEN_OFFSET 10
18#define SPI_XCOMM_SETTINGS_3WIRE BIT(6)
19#define SPI_XCOMM_SETTINGS_CS_HIGH BIT(5)
20#define SPI_XCOMM_SETTINGS_SAMPLE_END BIT(4)
21#define SPI_XCOMM_SETTINGS_CPHA BIT(3)
22#define SPI_XCOMM_SETTINGS_CPOL BIT(2)
23#define SPI_XCOMM_SETTINGS_CLOCK_DIV_MASK 0x3
24#define SPI_XCOMM_SETTINGS_CLOCK_DIV_64 0x2
25#define SPI_XCOMM_SETTINGS_CLOCK_DIV_16 0x1
26#define SPI_XCOMM_SETTINGS_CLOCK_DIV_4 0x0
27
28#define SPI_XCOMM_CMD_UPDATE_CONFIG 0x03
29#define SPI_XCOMM_CMD_WRITE 0x04
30#define SPI_XCOMM_CMD_GPIO_SET 0x05
31
32#define SPI_XCOMM_CLOCK 48000000
33
34struct spi_xcomm {
35 struct i2c_client *i2c;
36
37 struct gpio_chip gc;
38
39 u16 settings;
40 u16 chipselect;
41
42 unsigned int current_speed;
43
44 u8 buf[63];
45};
46
47static void spi_xcomm_gpio_set_value(struct gpio_chip *chip,
48 unsigned int offset, int val)
49{
50 struct spi_xcomm *spi_xcomm = gpiochip_get_data(chip);
51 unsigned char buf[2];
52
53 buf[0] = SPI_XCOMM_CMD_GPIO_SET;
54 buf[1] = !!val;
55
56 i2c_master_send(spi_xcomm->i2c, buf, 2);
57}
58
59static int spi_xcomm_gpio_get_direction(struct gpio_chip *chip,
60 unsigned int offset)
61{
62 return GPIO_LINE_DIRECTION_OUT;
63}
64
65static int spi_xcomm_gpio_add(struct spi_xcomm *spi_xcomm)
66{
67 struct device *dev = &spi_xcomm->i2c->dev;
68
69 if (!IS_ENABLED(CONFIG_GPIOLIB))
70 return 0;
71
72 spi_xcomm->gc.get_direction = spi_xcomm_gpio_get_direction;
73 spi_xcomm->gc.set = spi_xcomm_gpio_set_value;
74 spi_xcomm->gc.can_sleep = 1;
75 spi_xcomm->gc.base = -1;
76 spi_xcomm->gc.ngpio = 1;
77 spi_xcomm->gc.label = spi_xcomm->i2c->name;
78 spi_xcomm->gc.owner = THIS_MODULE;
79
80 return devm_gpiochip_add_data(dev, &spi_xcomm->gc, spi_xcomm);
81}
82
83static int spi_xcomm_sync_config(struct spi_xcomm *spi_xcomm, unsigned int len)
84{
85 u16 settings;
86 u8 *buf = spi_xcomm->buf;
87
88 settings = spi_xcomm->settings;
89 settings |= len << SPI_XCOMM_SETTINGS_LEN_OFFSET;
90
91 buf[0] = SPI_XCOMM_CMD_UPDATE_CONFIG;
92 put_unaligned_be16(settings, &buf[1]);
93 put_unaligned_be16(spi_xcomm->chipselect, &buf[3]);
94
95 return i2c_master_send(spi_xcomm->i2c, buf, 5);
96}
97
98static void spi_xcomm_chipselect(struct spi_xcomm *spi_xcomm,
99 struct spi_device *spi, int is_active)
100{
101 unsigned long cs = spi_get_chipselect(spi, 0);
102 u16 chipselect = spi_xcomm->chipselect;
103
104 if (is_active)
105 chipselect |= BIT(cs);
106 else
107 chipselect &= ~BIT(cs);
108
109 spi_xcomm->chipselect = chipselect;
110}
111
112static int spi_xcomm_setup_transfer(struct spi_xcomm *spi_xcomm,
113 struct spi_device *spi, struct spi_transfer *t,
114 unsigned int *settings)
115{
116 if (t->len > 62)
117 return -EINVAL;
118
119 if (t->speed_hz != spi_xcomm->current_speed) {
120 unsigned int divider;
121
122 divider = DIV_ROUND_UP(SPI_XCOMM_CLOCK, t->speed_hz);
123 if (divider >= 64)
124 *settings |= SPI_XCOMM_SETTINGS_CLOCK_DIV_64;
125 else if (divider >= 16)
126 *settings |= SPI_XCOMM_SETTINGS_CLOCK_DIV_16;
127 else
128 *settings |= SPI_XCOMM_SETTINGS_CLOCK_DIV_4;
129
130 spi_xcomm->current_speed = t->speed_hz;
131 }
132
133 if (spi->mode & SPI_CPOL)
134 *settings |= SPI_XCOMM_SETTINGS_CPOL;
135 else
136 *settings &= ~SPI_XCOMM_SETTINGS_CPOL;
137
138 if (spi->mode & SPI_CPHA)
139 *settings &= ~SPI_XCOMM_SETTINGS_CPHA;
140 else
141 *settings |= SPI_XCOMM_SETTINGS_CPHA;
142
143 if (spi->mode & SPI_3WIRE)
144 *settings |= SPI_XCOMM_SETTINGS_3WIRE;
145 else
146 *settings &= ~SPI_XCOMM_SETTINGS_3WIRE;
147
148 return 0;
149}
150
151static int spi_xcomm_txrx_bufs(struct spi_xcomm *spi_xcomm,
152 struct spi_device *spi, struct spi_transfer *t)
153{
154 int ret;
155
156 if (t->tx_buf) {
157 spi_xcomm->buf[0] = SPI_XCOMM_CMD_WRITE;
158 memcpy(spi_xcomm->buf + 1, t->tx_buf, t->len);
159
160 ret = i2c_master_send(spi_xcomm->i2c, spi_xcomm->buf, t->len + 1);
161 if (ret < 0)
162 return ret;
163 if (ret != t->len + 1)
164 return -EIO;
165 } else if (t->rx_buf) {
166 ret = i2c_master_recv(spi_xcomm->i2c, t->rx_buf, t->len);
167 if (ret < 0)
168 return ret;
169 if (ret != t->len)
170 return -EIO;
171 }
172
173 return t->len;
174}
175
176static int spi_xcomm_transfer_one(struct spi_controller *host,
177 struct spi_message *msg)
178{
179 struct spi_xcomm *spi_xcomm = spi_controller_get_devdata(host);
180 unsigned int settings = spi_xcomm->settings;
181 struct spi_device *spi = msg->spi;
182 unsigned int cs_change = 0;
183 struct spi_transfer *t;
184 bool is_first = true;
185 int status = 0;
186 bool is_last;
187
188 spi_xcomm_chipselect(spi_xcomm, spi, true);
189
190 list_for_each_entry(t, &msg->transfers, transfer_list) {
191 if (!t->tx_buf && !t->rx_buf && t->len) {
192 status = -EINVAL;
193 break;
194 }
195
196 status = spi_xcomm_setup_transfer(spi_xcomm, spi, t, &settings);
197 if (status < 0)
198 break;
199
200 is_last = list_is_last(&t->transfer_list, &msg->transfers);
201 cs_change = t->cs_change;
202
203 if (cs_change ^ is_last)
204 settings |= BIT(5);
205 else
206 settings &= ~BIT(5);
207
208 if (t->rx_buf) {
209 spi_xcomm->settings = settings;
210 status = spi_xcomm_sync_config(spi_xcomm, t->len);
211 if (status < 0)
212 break;
213 } else if (settings != spi_xcomm->settings || is_first) {
214 spi_xcomm->settings = settings;
215 status = spi_xcomm_sync_config(spi_xcomm, 0);
216 if (status < 0)
217 break;
218 }
219
220 if (t->len) {
221 status = spi_xcomm_txrx_bufs(spi_xcomm, spi, t);
222
223 if (status < 0)
224 break;
225
226 if (status > 0)
227 msg->actual_length += status;
228 }
229 status = 0;
230
231 spi_transfer_delay_exec(t);
232
233 is_first = false;
234 }
235
236 if (status != 0 || !cs_change)
237 spi_xcomm_chipselect(spi_xcomm, spi, false);
238
239 msg->status = status;
240 spi_finalize_current_message(host);
241
242 return status;
243}
244
245static int spi_xcomm_probe(struct i2c_client *i2c)
246{
247 struct spi_xcomm *spi_xcomm;
248 struct spi_controller *host;
249 int ret;
250
251 host = devm_spi_alloc_host(&i2c->dev, sizeof(*spi_xcomm));
252 if (!host)
253 return -ENOMEM;
254
255 spi_xcomm = spi_controller_get_devdata(host);
256 spi_xcomm->i2c = i2c;
257
258 host->num_chipselect = 16;
259 host->mode_bits = SPI_CPHA | SPI_CPOL | SPI_3WIRE;
260 host->bits_per_word_mask = SPI_BPW_MASK(8);
261 host->flags = SPI_CONTROLLER_HALF_DUPLEX;
262 host->transfer_one_message = spi_xcomm_transfer_one;
263 host->dev.of_node = i2c->dev.of_node;
264
265 ret = devm_spi_register_controller(&i2c->dev, host);
266 if (ret < 0)
267 return ret;
268
269 return spi_xcomm_gpio_add(spi_xcomm);
270}
271
272static const struct i2c_device_id spi_xcomm_ids[] = {
273 { "spi-xcomm" },
274 { },
275};
276MODULE_DEVICE_TABLE(i2c, spi_xcomm_ids);
277
278static struct i2c_driver spi_xcomm_driver = {
279 .driver = {
280 .name = "spi-xcomm",
281 },
282 .id_table = spi_xcomm_ids,
283 .probe = spi_xcomm_probe,
284};
285module_i2c_driver(spi_xcomm_driver);
286
287MODULE_LICENSE("GPL");
288MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
289MODULE_DESCRIPTION("Analog Devices AD-FMCOMMS1-EBZ board I2C-SPI bridge driver");