zephyr/drivers/modem/modem_iface_uart.c

171 lines
3.4 KiB
C

/** @file
* @brief interface for modem context
*
* UART-based modem interface implementation for modem context driver.
*/
/*
* Copyright (c) 2019 Foundries.io
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <logging/log.h>
LOG_MODULE_REGISTER(modem_iface_uart, CONFIG_MODEM_LOG_LEVEL);
#include <kernel.h>
#include <drivers/uart.h>
#include "modem_context.h"
#include "modem_iface_uart.h"
/**
* @brief Drains UART.
*
* @note Discards remaining data.
*
* @param *iface: modem interface.
*
* @retval None.
*/
static void modem_iface_uart_flush(struct modem_iface *iface)
{
u8_t c;
while (uart_fifo_read(iface->dev, &c, 1) > 0) {
continue;
}
}
/**
* @brief Modem interface interrupt handler.
*
* @note Fills interfaces ring buffer with received data.
* When ring buffer is full the data is discarded.
*
* @param *uart_dev: uart device.
*
* @retval None.
*/
static void modem_iface_uart_isr(struct device *uart_dev)
{
struct modem_context *ctx;
struct modem_iface_uart_data *data;
int rx = 0, ret;
/* lookup the modem context */
ctx = modem_context_from_iface_dev(uart_dev);
if (!ctx || !ctx->iface.iface_data) {
return;
}
data = (struct modem_iface_uart_data *)(ctx->iface.iface_data);
/* get all of the data off UART as fast as we can */
while (uart_irq_update(ctx->iface.dev) &&
uart_irq_rx_ready(ctx->iface.dev)) {
rx = uart_fifo_read(ctx->iface.dev,
data->isr_buf, data->isr_buf_len);
if (rx <= 0) {
continue;
}
ret = ring_buf_put(&data->rx_rb, data->isr_buf, rx);
if (ret != rx) {
LOG_ERR("Rx buffer doesn't have enough space. "
"Bytes pending: %d, written: %d",
rx, ret);
modem_iface_uart_flush(&ctx->iface);
k_sem_give(&data->rx_sem);
break;
}
k_sem_give(&data->rx_sem);
}
}
static int modem_iface_uart_read(struct modem_iface *iface,
u8_t *buf, size_t size, size_t *bytes_read)
{
struct modem_iface_uart_data *data;
if (!iface || !iface->iface_data) {
return -EINVAL;
}
if (size == 0) {
*bytes_read = 0;
return 0;
}
data = (struct modem_iface_uart_data *)(iface->iface_data);
*bytes_read = ring_buf_get(&data->rx_rb, buf, size);
return 0;
}
static int modem_iface_uart_write(struct modem_iface *iface,
const u8_t *buf, size_t size)
{
if (!iface || !iface->iface_data) {
return -EINVAL;
}
if (size == 0) {
return 0;
}
do {
uart_poll_out(iface->dev, *buf++);
} while (--size);
return 0;
}
int modem_iface_uart_init_dev(struct modem_iface *iface,
const char *dev_name)
{
/* get UART device */
iface->dev = device_get_binding(dev_name);
if (!iface->dev) {
return -ENODEV;
}
uart_irq_rx_disable(iface->dev);
uart_irq_tx_disable(iface->dev);
modem_iface_uart_flush(iface);
uart_irq_callback_set(iface->dev, modem_iface_uart_isr);
uart_irq_rx_enable(iface->dev);
return 0;
}
int modem_iface_uart_init(struct modem_iface *iface,
struct modem_iface_uart_data *data,
const char *dev_name)
{
int ret;
if (!iface || !data) {
return -EINVAL;
}
iface->iface_data = data;
iface->read = modem_iface_uart_read;
iface->write = modem_iface_uart_write;
ring_buf_init(&data->rx_rb, data->rx_rb_buf_len, data->rx_rb_buf);
k_sem_init(&data->rx_sem, 0, 1);
/* get UART device */
ret = modem_iface_uart_init_dev(iface, dev_name);
if (ret < 0) {
iface->iface_data = NULL;
iface->read = NULL;
iface->write = NULL;
return ret;
}
return 0;
}