zephyr/drivers/serial/usart_mcux_lpc.c

127 lines
3.1 KiB
C

/*
* Copyright (c) 2017, NXP
*
* SPDX-License-Identifier: Apache-2.0
*/
/** @file
* @brief USART driver for LPC54XXX family
*
* Note:
* - Only basic USART features sufficient to support printf functionality
* are currently implemented.
* - The driver works only in polling mode, interrupt mode is not implemented.
*/
#include <errno.h>
#include <device.h>
#include <uart.h>
#include <fsl_lpc_usart.h>
#include <fsl_clock.h>
#include <soc.h>
#include <fsl_device_registers.h>
struct usart_mcux_lpc_config {
USART_Type *base;
clock_name_t clock_source;
u32_t baud_rate;
};
struct usart_mcux_lpc_data {
/* put irq call back instance when required */
};
static int usart_mcux_lpc_poll_in(struct device *dev, unsigned char *c)
{
const struct usart_mcux_lpc_config *config = dev->config->config_info;
u32_t flags = USART_GetStatusFlags(config->base);
int ret = -1;
if (flags & kUSART_RxFifoFullFlag) {
*c = USART_ReadByte(config->base);
ret = 0;
}
return ret;
}
static unsigned char usart_mcux_lpc_poll_out(struct device *dev,
unsigned char c)
{
const struct usart_mcux_lpc_config *config = dev->config->config_info;
/* Wait until space is available in TX FIFO */
while (!(USART_GetStatusFlags(config->base) & kUSART_TxFifoEmptyFlag))
;
USART_WriteByte(config->base, c);
return c;
}
static int usart_mcux_lpc_err_check(struct device *dev)
{
const struct usart_mcux_lpc_config *config = dev->config->config_info;
u32_t flags = USART_GetStatusFlags(config->base);
int err = 0;
if (flags & kStatus_USART_RxRingBufferOverrun) {
err |= UART_ERROR_OVERRUN;
}
if (flags & kStatus_USART_ParityError) {
err |= UART_ERROR_PARITY;
}
if (flags & kStatus_USART_FramingError) {
err |= UART_ERROR_FRAMING;
}
USART_ClearStatusFlags(config->base,
kStatus_USART_RxRingBufferOverrun |
kStatus_USART_ParityError |
kStatus_USART_FramingError);
return err;
}
static int usart_mcux_lpc_init(struct device *dev)
{
const struct usart_mcux_lpc_config *config = dev->config->config_info;
usart_config_t usart_config;
u32_t clock_freq;
clock_freq = CLOCK_GetFreq(config->clock_source);
USART_GetDefaultConfig(&usart_config);
usart_config.enableTx = true;
usart_config.enableRx = true;
usart_config.baudRate_Bps = config->baud_rate;
USART_Init(config->base, &usart_config, clock_freq);
return 0;
}
static const struct uart_driver_api usart_mcux_lpc_driver_api = {
.poll_in = usart_mcux_lpc_poll_in,
.poll_out = usart_mcux_lpc_poll_out,
.err_check = usart_mcux_lpc_err_check,
};
#ifdef CONFIG_USART_MCUX_LPC_0
static const struct usart_mcux_lpc_config usart_mcux_lpc_0_config = {
.base = (USART_Type *)CONFIG_USART_MCUX_LPC_0_BASE_ADDRESS,
.clock_source = kCLOCK_Flexcomm0,
.baud_rate = CONFIG_USART_MCUX_LPC_0_BAUD_RATE,
};
static struct usart_mcux_lpc_data usart_mcux_lpc_0_data;
DEVICE_AND_API_INIT(usart_0, CONFIG_USART_MCUX_LPC_0_NAME,
&usart_mcux_lpc_init,
&usart_mcux_lpc_0_data, &usart_mcux_lpc_0_config,
PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
&usart_mcux_lpc_driver_api);
#endif /* CONFIG_USART_MCUX_LPC_0 */