1 /*
2 * Copyright (c) 2023 Antmicro <www.antmicro.com>
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 #define DT_DRV_COMPAT fujitsu_mb85rcxx
8
9 #include <zephyr/device.h>
10 #include <zephyr/drivers/eeprom.h>
11 #include <zephyr/drivers/gpio.h>
12 #include <zephyr/drivers/i2c.h>
13 #include <zephyr/kernel.h>
14 #include <zephyr/sys/byteorder.h>
15
16 #include <zephyr/logging/log.h>
17 LOG_MODULE_REGISTER(EEPROM_MB85RCXX, CONFIG_EEPROM_LOG_LEVEL);
18
19 struct mb85rcxx_config {
20 struct i2c_dt_spec i2c;
21 struct gpio_dt_spec wp_gpio;
22 size_t size;
23 size_t pagesize;
24 uint8_t addr_width;
25 bool readonly;
26 };
27
28 struct mb85rcxx_data {
29 struct k_mutex lock;
30 };
31
mb85rcxx_write_protect_set(const struct device * dev,int value)32 static int mb85rcxx_write_protect_set(const struct device *dev, int value)
33 {
34 const struct mb85rcxx_config *cfg = dev->config;
35
36 if (!cfg->wp_gpio.port) {
37 return 0;
38 }
39
40 return gpio_pin_set_dt(&cfg->wp_gpio, value);
41 }
42
mb85rcxx_translate_address(const struct device * dev,off_t offset,uint8_t * addr)43 static uint16_t mb85rcxx_translate_address(const struct device *dev, off_t offset, uint8_t *addr)
44 {
45 const struct mb85rcxx_config *cfg = dev->config;
46
47 off_t page_offset = offset % cfg->pagesize;
48
49 if (cfg->addr_width > 8) {
50 sys_put_be16(page_offset, addr);
51 addr[0] &= BIT_MASK(cfg->addr_width - 8);
52 } else {
53 addr[0] = page_offset & BIT_MASK(cfg->addr_width);
54 }
55
56 return cfg->i2c.addr + (offset >> cfg->addr_width);
57 }
58
mb85rcxx_remaining_len_in_page(const struct device * dev,off_t offset,size_t len)59 static size_t mb85rcxx_remaining_len_in_page(const struct device *dev, off_t offset, size_t len)
60 {
61 const struct mb85rcxx_config *cfg = dev->config;
62 off_t page_offset = offset % cfg->pagesize;
63 size_t rem = cfg->pagesize - page_offset;
64
65 if (rem > len) {
66 rem = len;
67 }
68
69 return rem;
70 }
71
mb85rcxx_init(const struct device * dev)72 static int mb85rcxx_init(const struct device *dev)
73 {
74 const struct mb85rcxx_config *cfg = dev->config;
75 struct mb85rcxx_data *data = dev->data;
76
77 k_mutex_init(&data->lock);
78
79 if (!i2c_is_ready_dt(&cfg->i2c)) {
80 LOG_ERR("i2c bus device not ready");
81 return -EINVAL;
82 }
83
84 if (cfg->wp_gpio.port) {
85 if (!gpio_is_ready_dt(&cfg->wp_gpio)) {
86 LOG_ERR("wp gpio device not ready");
87 return -EINVAL;
88 }
89
90 int err = gpio_pin_configure_dt(&cfg->wp_gpio, GPIO_OUTPUT_ACTIVE);
91
92 if (err) {
93 LOG_ERR("failed to configure WP GPIO pin (err %d)", err);
94 return err;
95 }
96 }
97 return 0;
98 }
99
mb85rcxx_read(const struct device * dev,off_t offset,void * buf,size_t len)100 static int mb85rcxx_read(const struct device *dev, off_t offset, void *buf, size_t len)
101 {
102 const struct mb85rcxx_config *cfg = dev->config;
103 struct mb85rcxx_data *data = dev->data;
104 uint8_t addr[2];
105 uint16_t i2c_addr;
106 size_t len_in_page;
107 int ret;
108
109 if (offset + len > cfg->size) {
110 LOG_ERR("attempt to read past device boundary");
111 return -EINVAL;
112 }
113
114 k_mutex_lock(&data->lock, K_FOREVER);
115
116 while (len) {
117 i2c_addr = mb85rcxx_translate_address(dev, offset, addr);
118 len_in_page = mb85rcxx_remaining_len_in_page(dev, offset, len);
119
120 ret = i2c_write_read(cfg->i2c.bus, i2c_addr, addr, DIV_ROUND_UP(cfg->addr_width, 8),
121 buf, len_in_page);
122 if (ret < 0) {
123 LOG_ERR("failed to read FRAM (err %d)", ret);
124 k_mutex_unlock(&data->lock);
125 return ret;
126 }
127
128 len -= len_in_page;
129 *(char *)&buf += len_in_page;
130 offset += len_in_page;
131 }
132
133 k_mutex_unlock(&data->lock);
134 return 0;
135 }
136
mb85rcxx_i2c_write(const struct device * dev,uint16_t i2c_addr,uint8_t * addr,const void * buf,size_t len)137 static int mb85rcxx_i2c_write(const struct device *dev, uint16_t i2c_addr, uint8_t *addr,
138 const void *buf, size_t len)
139 {
140 const struct mb85rcxx_config *cfg = dev->config;
141 struct i2c_msg msgs[2];
142
143 msgs[0].buf = addr;
144 msgs[0].len = DIV_ROUND_UP(cfg->addr_width, 8);
145 msgs[0].flags = I2C_MSG_WRITE;
146
147 msgs[1].buf = (void *)buf;
148 msgs[1].len = len;
149 msgs[1].flags = I2C_MSG_WRITE | I2C_MSG_STOP;
150
151 return i2c_transfer(cfg->i2c.bus, &msgs[0], 2, i2c_addr);
152 }
153
mb85rcxx_write(const struct device * dev,off_t offset,const void * buf,size_t len)154 static int mb85rcxx_write(const struct device *dev, off_t offset, const void *buf, size_t len)
155 {
156 const struct mb85rcxx_config *cfg = dev->config;
157 struct mb85rcxx_data *data = dev->data;
158 uint8_t addr[2];
159 uint16_t i2c_addr;
160 size_t len_in_page;
161 int ret;
162
163 if (cfg->readonly) {
164 LOG_ERR("attempt to write to read-only device");
165 return -EACCES;
166 }
167
168 if (offset + len > cfg->size) {
169 LOG_ERR("attempt to write past device boundary");
170 return -EINVAL;
171 }
172
173 ret = mb85rcxx_write_protect_set(dev, 0);
174 if (ret) {
175 LOG_ERR("failed to write-enable FRAM (err %d)", ret);
176 return ret;
177 }
178
179 k_mutex_lock(&data->lock, K_FOREVER);
180
181 while (len) {
182 i2c_addr = mb85rcxx_translate_address(dev, offset, addr);
183 len_in_page = mb85rcxx_remaining_len_in_page(dev, offset, len);
184
185 ret = mb85rcxx_i2c_write(dev, i2c_addr, addr, buf, len);
186 if (ret < 0) {
187 LOG_ERR("failed to write to FRAM (err %d)", ret);
188 k_mutex_unlock(&data->lock);
189 return ret;
190 }
191
192 len -= len_in_page;
193 *(char *)&buf += len_in_page;
194 offset += len_in_page;
195 }
196
197 k_mutex_unlock(&data->lock);
198 mb85rcxx_write_protect_set(dev, 1);
199 return ret;
200 }
201
mb85rcxx_get_size(const struct device * dev)202 static size_t mb85rcxx_get_size(const struct device *dev)
203 {
204 const struct mb85rcxx_config *cfg = dev->config;
205
206 return cfg->size;
207 }
208
209 static DEVICE_API(eeprom, mb85rcxx_driver_api) = {
210 .read = &mb85rcxx_read,
211 .write = &mb85rcxx_write,
212 .size = &mb85rcxx_get_size,
213 };
214
215 #define MB85RCXX_DEFINE(inst) \
216 static struct mb85rcxx_data mb85rcxx_data_##inst; \
217 \
218 static const struct mb85rcxx_config mb85rcxx_config_##inst = { \
219 .i2c = I2C_DT_SPEC_INST_GET(inst), \
220 IF_ENABLED(DT_INST_NODE_HAS_PROP(inst, wp_gpios), \
221 (.wp_gpio = GPIO_DT_SPEC_INST_GET(inst, wp_gpios),)) \
222 .size = DT_INST_PROP(inst, size), \
223 .pagesize = \
224 COND_CODE_1(DT_INST_NODE_HAS_PROP(inst, pagesize), \
225 (DT_INST_PROP(inst, pagesize)), (DT_INST_PROP(inst, size))), \
226 .addr_width = DT_INST_PROP(inst, address_width), \
227 .readonly = DT_INST_PROP(inst, read_only)}; \
228 \
229 DEVICE_DT_INST_DEFINE(inst, mb85rcxx_init, NULL, &mb85rcxx_data_##inst, \
230 &mb85rcxx_config_##inst, POST_KERNEL, CONFIG_EEPROM_INIT_PRIORITY, \
231 &mb85rcxx_driver_api);
232
233 DT_INST_FOREACH_STATUS_OKAY(MB85RCXX_DEFINE)
234