zephyr/drivers/serial/usart_gd32.c
Gerson Fernando Budke 45d60c4d4c drivers: serial: Add gd32 uart driver
Introduce minimal serial driver support for gigadevice soc.

Signed-off-by: Gerson Fernando Budke <gerson.budke@atl-electronics.com>
2021-10-28 11:17:25 +02:00

118 lines
2.8 KiB
C

/*
* Copyright (c) 2021, ATL Electronics
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT gd_gd32_usart
#include <drivers/uart.h>
struct gd32_usart_config {
uint32_t reg;
uint32_t rcu_periph_clock;
};
struct gd32_usart_data {
uint32_t baud_rate;
};
static int usart_gd32_init(const struct device *dev)
{
const struct gd32_usart_config *const cfg = dev->config;
struct gd32_usart_data *const data = dev->data;
/* NOTE: pins are configured at board_init till pinctrl be available */
rcu_periph_clock_enable(cfg->rcu_periph_clock);
usart_deinit(cfg->reg);
usart_baudrate_set(cfg->reg, data->baud_rate);
usart_word_length_set(cfg->reg, USART_WL_8BIT);
usart_parity_config(cfg->reg, USART_PM_NONE);
usart_stop_bit_set(cfg->reg, USART_STB_1BIT);
usart_parity_config(cfg->reg, USART_PM_NONE);
usart_receive_config(cfg->reg, USART_RECEIVE_ENABLE);
usart_transmit_config(cfg->reg, USART_TRANSMIT_ENABLE);
usart_enable(cfg->reg);
return 0;
}
static int usart_gd32_poll_in(const struct device *dev, unsigned char *c)
{
const struct gd32_usart_config *const cfg = dev->config;
uint32_t status;
status = usart_flag_get(cfg->reg, USART_FLAG_RBNE);
if (!status) {
return -EPERM;
}
*c = usart_data_receive(cfg->reg);
return 0;
}
static void usart_gd32_poll_out(const struct device *dev, unsigned char c)
{
const struct gd32_usart_config *const cfg = dev->config;
usart_data_transmit(cfg->reg, c);
while (usart_flag_get(cfg->reg, USART_FLAG_TBE) == RESET) {
;
}
}
static int usart_gd32_err_check(const struct device *dev)
{
const struct gd32_usart_config *const cfg = dev->config;
uint32_t status = USART_STAT0(cfg->reg);
int errors = 0;
if (status & USART_FLAG_ORERR) {
usart_flag_clear(cfg->reg, USART_FLAG_ORERR);
errors |= UART_ERROR_OVERRUN;
}
if (status & USART_FLAG_PERR) {
usart_flag_clear(cfg->reg, USART_FLAG_PERR);
errors |= UART_ERROR_PARITY;
}
if (status & USART_FLAG_FERR) {
usart_flag_clear(cfg->reg, USART_FLAG_FERR);
errors |= UART_ERROR_FRAMING;
}
usart_flag_clear(cfg->reg, USART_FLAG_NERR);
return errors;
}
static const struct uart_driver_api usart_gd32_driver_api = {
.poll_in = usart_gd32_poll_in,
.poll_out = usart_gd32_poll_out,
.err_check = usart_gd32_err_check,
};
#define GD32_USART_INIT(n) \
static struct gd32_usart_data usart##n##_gd32_data = { \
.baud_rate = DT_INST_PROP(n, current_speed), \
}; \
static const struct gd32_usart_config usart##n##_gd32_config = { \
.reg = DT_INST_REG_ADDR(n), \
.rcu_periph_clock = DT_INST_PROP(n, rcu_periph_clock), \
}; \
DEVICE_DT_INST_DEFINE(n, &usart_gd32_init, \
NULL, \
&usart##n##_gd32_data, \
&usart##n##_gd32_config, PRE_KERNEL_1, \
CONFIG_KERNEL_INIT_PRIORITY_DEVICE, \
&usart_gd32_driver_api);
DT_INST_FOREACH_STATUS_OKAY(GD32_USART_INIT)