1 /*
2 * Copyright (c) 2022 Matthias Freese
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 #define DT_DRV_COMPAT ti_sn74hc595
8
9 /**
10 * @file Driver for 74 HC shift register
11 */
12
13 #include <zephyr/drivers/gpio.h>
14 #include <zephyr/drivers/spi.h>
15 #include <zephyr/kernel.h>
16 #include <zephyr/device.h>
17 #include <zephyr/kernel.h>
18
19 #include <zephyr/drivers/gpio/gpio_utils.h>
20
21 #include <zephyr/logging/log.h>
22 LOG_MODULE_REGISTER(gpio_sn74hc595, CONFIG_GPIO_LOG_LEVEL);
23
24 #if CONFIG_SPI_INIT_PRIORITY >= CONFIG_GPIO_SN74HC595_INIT_PRIORITY
25 #error SPI_INIT_PRIORITY must be lower than SN74HC595_INIT_PRIORITY
26 #endif
27
28 struct gpio_sn74hc595_config {
29 /* gpio_driver_config needs to be first */
30 struct gpio_driver_config config;
31
32 struct spi_dt_spec bus;
33 struct gpio_dt_spec reset_gpio;
34 };
35
36 struct gpio_sn74hc595_drv_data {
37 /* gpio_driver_data needs to be first */
38 struct gpio_driver_data data;
39
40 struct k_mutex lock;
41 uint8_t output;
42 };
43
sn74hc595_spi_write(const struct device * dev,void * buf,size_t len_bytes)44 static int sn74hc595_spi_write(const struct device *dev, void *buf, size_t len_bytes)
45 {
46 const struct gpio_sn74hc595_config *config = dev->config;
47
48 __ASSERT(((buf != NULL) || (len_bytes == 0)), "no valid buffer given");
49 __ASSERT(!k_is_in_isr(), "attempt to access SPI from ISR");
50
51 struct spi_buf tx_buf[] = { { .buf = buf, .len = len_bytes } };
52 const struct spi_buf_set tx = { .buffers = tx_buf, .count = 1 };
53
54 return spi_write_dt(&config->bus, &tx);
55 }
56
gpio_sn74hc595_config(const struct device * dev,gpio_pin_t pin,gpio_flags_t flags)57 static int gpio_sn74hc595_config(const struct device *dev, gpio_pin_t pin, gpio_flags_t flags)
58 {
59 ARG_UNUSED(dev);
60 ARG_UNUSED(pin);
61 ARG_UNUSED(flags);
62 return 0;
63 }
64
gpio_sn74hc595_port_get_raw(const struct device * dev,uint32_t * value)65 static int gpio_sn74hc595_port_get_raw(const struct device *dev, uint32_t *value)
66 {
67 struct gpio_sn74hc595_drv_data *drv_data = dev->data;
68
69 k_mutex_lock(&drv_data->lock, K_FOREVER);
70
71 *value = drv_data->output;
72
73 k_mutex_unlock(&drv_data->lock);
74
75 return 0;
76 }
77
gpio_sn74hc595_port_set_masked_raw(const struct device * dev,uint32_t mask,uint32_t value)78 static int gpio_sn74hc595_port_set_masked_raw(const struct device *dev, uint32_t mask,
79 uint32_t value)
80 {
81 struct gpio_sn74hc595_drv_data *drv_data = dev->data;
82 int ret = 0;
83 uint8_t output;
84
85 k_mutex_lock(&drv_data->lock, K_FOREVER);
86
87 /* check if we need to do something at all */
88 /* current output differs from new masked value */
89 if ((drv_data->output & mask) != (mask & value)) {
90 output = (drv_data->output & ~mask) | (mask & value);
91
92 ret = sn74hc595_spi_write(dev, &output, 1U);
93 if (ret < 0) {
94 goto unlock;
95 }
96
97 drv_data->output = output;
98 }
99
100 unlock:
101 k_mutex_unlock(&drv_data->lock);
102 return ret;
103 }
104
gpio_sn74hc595_port_set_bits_raw(const struct device * dev,uint32_t mask)105 static int gpio_sn74hc595_port_set_bits_raw(const struct device *dev, uint32_t mask)
106 {
107 return gpio_sn74hc595_port_set_masked_raw(dev, mask, mask);
108 }
109
gpio_sn74hc595_port_clear_bits_raw(const struct device * dev,uint32_t mask)110 static int gpio_sn74hc595_port_clear_bits_raw(const struct device *dev, uint32_t mask)
111 {
112 return gpio_sn74hc595_port_set_masked_raw(dev, mask, 0U);
113 }
114
gpio_sn74hc595_port_toggle_bits(const struct device * dev,uint32_t mask)115 static int gpio_sn74hc595_port_toggle_bits(const struct device *dev, uint32_t mask)
116 {
117 struct gpio_sn74hc595_drv_data *drv_data = dev->data;
118 int ret;
119 uint8_t toggled_output;
120
121 k_mutex_lock(&drv_data->lock, K_FOREVER);
122
123 toggled_output = drv_data->output ^ mask;
124
125 ret = sn74hc595_spi_write(dev, &toggled_output, 1U);
126 if (ret < 0) {
127 goto unlock;
128 }
129
130 drv_data->output ^= mask;
131
132 unlock:
133 k_mutex_unlock(&drv_data->lock);
134 return ret;
135 }
136
137 static const struct gpio_driver_api gpio_sn74hc595_drv_api_funcs = {
138 .pin_configure = gpio_sn74hc595_config,
139 .port_get_raw = gpio_sn74hc595_port_get_raw,
140 .port_set_masked_raw = gpio_sn74hc595_port_set_masked_raw,
141 .port_set_bits_raw = gpio_sn74hc595_port_set_bits_raw,
142 .port_clear_bits_raw = gpio_sn74hc595_port_clear_bits_raw,
143 .port_toggle_bits = gpio_sn74hc595_port_toggle_bits,
144 };
145
146 /**
147 * @brief Initialization function of sn74hc595
148 *
149 * @param dev Device struct
150 * @return 0 if successful, failed otherwise.
151 */
gpio_sn74hc595_init(const struct device * dev)152 static int gpio_sn74hc595_init(const struct device *dev)
153 {
154 const struct gpio_sn74hc595_config *config = dev->config;
155 struct gpio_sn74hc595_drv_data *drv_data = dev->data;
156
157 if (!spi_is_ready_dt(&config->bus)) {
158 LOG_ERR("SPI bus %s not ready", config->bus.bus->name);
159 return -ENODEV;
160 }
161
162 if (!gpio_is_ready_dt(&config->reset_gpio)) {
163 LOG_ERR("GPIO port %s not ready", config->reset_gpio.port->name);
164 return -ENODEV;
165 }
166
167 if (gpio_pin_configure_dt(&config->reset_gpio, GPIO_OUTPUT_ACTIVE) < 0) {
168 LOG_ERR("Unable to configure RST GPIO pin %u", config->reset_gpio.pin);
169 return -EINVAL;
170 }
171
172 gpio_pin_set(config->reset_gpio.port, config->reset_gpio.pin, 0);
173
174 drv_data->output = 0U;
175 return 0;
176 }
177
178 #define SN74HC595_SPI_OPERATION \
179 ((uint16_t)(SPI_OP_MODE_MASTER | SPI_TRANSFER_MSB | SPI_WORD_SET(8)))
180
181 #define SN74HC595_INIT(n) \
182 static struct gpio_sn74hc595_drv_data sn74hc595_data_##n = { \
183 .output = 0, \
184 .lock = Z_MUTEX_INITIALIZER(sn74hc595_data_##n.lock), \
185 }; \
186 \
187 static const struct gpio_sn74hc595_config sn74hc595_config_##n = { \
188 .config = { \
189 .port_pin_mask = \
190 GPIO_PORT_PIN_MASK_FROM_DT_INST(n), \
191 }, \
192 .bus = SPI_DT_SPEC_INST_GET(n, SN74HC595_SPI_OPERATION, 0), \
193 .reset_gpio = GPIO_DT_SPEC_INST_GET(n, reset_gpios), \
194 }; \
195 \
196 DEVICE_DT_DEFINE(DT_DRV_INST(n), &gpio_sn74hc595_init, NULL, \
197 &sn74hc595_data_##n, &sn74hc595_config_##n, POST_KERNEL, \
198 CONFIG_GPIO_SN74HC595_INIT_PRIORITY, &gpio_sn74hc595_drv_api_funcs);
199
200 DT_INST_FOREACH_STATUS_OKAY(SN74HC595_INIT)
201
