1 /*
2 * Copyright (c) 2023 Ayush Singh <ayushdevel1325@gmail.com>
3 * Copyright (c) 2021 Jason Kridner, BeagleBoard.org Foundation
4 * Copyright (c) 2020 Innoseis BV
5 *
6 * Based on i2c_tca9656a.c
7 *
8 * SPDX-License-Identifier: Apache-2.0
9 */
10
11 #define DT_DRV_COMPAT gpio_i2c_switch
12
13 #define GPIO_I2C_TOGGLE_DELAY_US 1
14 #define GPIO_I2C_LOCK_TIMEOUT_US (GPIO_I2C_TOGGLE_DELAY_US * 2 + 100)
15
16 #include <zephyr/kernel.h>
17 #include <zephyr/device.h>
18 #include <zephyr/devicetree.h>
19 #include <zephyr/drivers/i2c.h>
20 #include <zephyr/drivers/gpio.h>
21 #include <zephyr/logging/log.h>
22
23 LOG_MODULE_REGISTER(gpio_i2c_switch, CONFIG_I2C_LOG_LEVEL);
24
25 struct gpio_i2c_switch_config {
26 const struct device *bus;
27 const struct gpio_dt_spec gpio;
28 };
29
30 struct gpio_i2c_switch_data {
31 struct k_mutex lock;
32 };
33
gpio_i2c_switch_configure(const struct device * dev,uint32_t dev_config)34 static int gpio_i2c_switch_configure(const struct device *dev, uint32_t dev_config)
35 {
36 const struct gpio_i2c_switch_config *config = dev->config;
37
38 return i2c_configure(config->bus, dev_config);
39 }
40
gpio_i2c_switch_transfer(const struct device * dev,struct i2c_msg * msgs,uint8_t num_msgs,uint16_t addr)41 static int gpio_i2c_switch_transfer(const struct device *dev, struct i2c_msg *msgs,
42 uint8_t num_msgs, uint16_t addr)
43 {
44 int res;
45 struct gpio_i2c_switch_data *data = dev->data;
46 const struct gpio_i2c_switch_config *config = dev->config;
47
48 res = k_mutex_lock(&data->lock, K_USEC(GPIO_I2C_LOCK_TIMEOUT_US));
49 if (res != 0) {
50 return res;
51 }
52
53 /* enable switch */
54 gpio_pin_set_dt(&config->gpio, 1);
55 k_busy_wait(GPIO_I2C_TOGGLE_DELAY_US);
56
57 res = i2c_transfer(config->bus, msgs, num_msgs, addr);
58
59 /* disable switch */
60 gpio_pin_set_dt(&config->gpio, 0);
61 k_busy_wait(GPIO_I2C_TOGGLE_DELAY_US);
62 k_mutex_unlock(&data->lock);
63
64 return res;
65 }
66
67 static const struct i2c_driver_api gpio_i2c_switch_api_funcs = {
68 .configure = gpio_i2c_switch_configure,
69 .transfer = gpio_i2c_switch_transfer,
70 };
71
gpio_i2c_switch_init(const struct device * dev)72 static int gpio_i2c_switch_init(const struct device *dev)
73 {
74 const struct gpio_i2c_switch_config *config = dev->config;
75 struct gpio_i2c_switch_data *data = dev->data;
76
77 k_mutex_init(&data->lock);
78
79 return gpio_pin_configure_dt(&config->gpio, GPIO_OUTPUT_INACTIVE);
80 }
81
82 #define DEFINE_GPIO_I2C_SWITCH(inst) \
83 \
84 static struct gpio_i2c_switch_data gpio_i2c_switch_dev_data_##inst; \
85 \
86 static const struct gpio_i2c_switch_config gpio_i2c_switch_dev_cfg_##inst = { \
87 .bus = DEVICE_DT_GET(DT_PHANDLE(DT_DRV_INST(inst), controller)), \
88 .gpio = GPIO_DT_SPEC_GET(DT_DRV_INST(inst), gpios), \
89 }; \
90 \
91 DEVICE_DT_INST_DEFINE(inst, gpio_i2c_switch_init, device_pm_control_nop, \
92 &gpio_i2c_switch_dev_data_##inst, &gpio_i2c_switch_dev_cfg_##inst, \
93 POST_KERNEL, CONFIG_I2C_INIT_PRIORITY, &gpio_i2c_switch_api_funcs);
94
95 DT_INST_FOREACH_STATUS_OKAY(DEFINE_GPIO_I2C_SWITCH)
96
