mbed-os/targets/TARGET_Maxim/TARGET_MAX32625/mxc/uart.c

654 lines
18 KiB
C

/*******************************************************************************
* Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
* OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* Except as contained in this notice, the name of Maxim Integrated
* Products, Inc. shall not be used except as stated in the Maxim Integrated
* Products, Inc. Branding Policy.
*
* The mere transfer of this software does not imply any licenses
* of trade secrets, proprietary technology, copyrights, patents,
* trademarks, maskwork rights, or any other form of intellectual
* property whatsoever. Maxim Integrated Products, Inc. retains all
* ownership rights.
*
* $Date: 2016-07-28 15:01:10 -0500 (Thu, 28 Jul 2016) $
* $Revision: 23823 $
*
******************************************************************************/
/**
* @file uart.c
* @brief UART diver source.
*/
/***** Includes *****/
#include <string.h>
#include "mxc_assert.h"
#include "mxc_lock.h"
#include "mxc_sys.h"
#include "uart.h"
/***** Definitions *****/
#define UART_ERRORS (MXC_F_UART_INTEN_RX_FIFO_OVERFLOW | \
MXC_F_UART_INTEN_RX_FRAMING_ERR | \
MXC_F_UART_INTEN_RX_PARITY_ERR)
#define UART_READ_INTS (MXC_F_UART_INTEN_RX_FIFO_AF | \
MXC_F_UART_INTEN_RX_FIFO_NOT_EMPTY | \
MXC_F_UART_INTEN_RX_STALLED | \
UART_ERRORS)
#define UART_WRITE_INTS (MXC_F_UART_INTEN_TX_UNSTALLED | \
MXC_F_UART_INTEN_TX_FIFO_AE)
#define UART_RXFIFO_USABLE (MXC_UART_FIFO_DEPTH-3)
/***** Globals *****/
// Saves the state of the non-blocking read requests
static uart_req_t *rx_states[MXC_CFG_UART_INSTANCES];
// Saves the state of the non-blocking write requests
static uart_req_t *tx_states[MXC_CFG_UART_INSTANCES];
/***** Functions *****/
static void UART_WriteHandler(mxc_uart_regs_t *uart, uart_req_t *req, int uart_num);
static void UART_ReadHandler(mxc_uart_regs_t *uart, uart_req_t *req, int uart_num,
uint32_t flags);
/******************************************************************************/
int UART_Init(mxc_uart_regs_t *uart, const uart_cfg_t *cfg, const sys_cfg_uart_t *sys_cfg)
{
int err;
int uart_num;
uint32_t uart_clk;
uint8_t baud_shift;
uint16_t baud_div;
uint32_t baud, diff_baud;
uint32_t baud_1, diff_baud_1;
// Check the input parameters
uart_num = MXC_UART_GET_IDX(uart);
MXC_ASSERT(uart_num >= 0);
// Set system level configurations
if(sys_cfg != NULL) {
if ((err = SYS_UART_Init(uart, cfg, sys_cfg)) != E_NO_ERROR) {
return err;
}
}
// Initialize state pointers
rx_states[uart_num] = NULL;
tx_states[uart_num] = NULL;
// Drain FIFOs and enable UART
uart->ctrl = 0;
uart->ctrl = (MXC_F_UART_CTRL_UART_EN | MXC_F_UART_CTRL_TX_FIFO_EN |
MXC_F_UART_CTRL_RX_FIFO_EN |
(UART_RXFIFO_USABLE << MXC_F_UART_CTRL_RTS_LEVEL_POS));
// Configure data size, stop bit, parity, cts, and rts
uart->ctrl |= ((cfg->size << MXC_F_UART_CTRL_DATA_SIZE_POS) |
(cfg->extra_stop << MXC_F_UART_CTRL_EXTRA_STOP_POS) |
(cfg->parity << MXC_F_UART_CTRL_PARITY_POS) |
(cfg->cts << MXC_F_UART_CTRL_CTS_EN_POS) |
(cfg->rts << MXC_F_UART_CTRL_RTS_EN_POS));
// Configure the baud rate and divisor
uart_clk = SYS_UART_GetFreq(uart);
MXC_ASSERT(uart_clk > 0);
baud_shift = 2;
baud_div = (uart_clk / (cfg->baud * 4));
// Can not support higher frequencies
if(!baud_div) {
return E_NOT_SUPPORTED;
}
// Decrease the divisor if baud_div is overflowing
while(baud_div > 0xFF) {
if(baud_shift == 0) {
return E_NOT_SUPPORTED;
}
baud_shift--;
baud_div = (uart_clk / (cfg->baud * (16 >> baud_shift)));
}
// Adjust baud_div so we don't overflow with the calculations below
if(baud_div == 0xFF) {
baud_div = 0xFE;
}
if(baud_div == 0) {
baud_div = 1;
}
// Figure out if the truncation increased the error
baud = (uart_clk / (baud_div * (16 >> baud_shift)));
baud_1 = (uart_clk / ((baud_div+1) * (16 >> baud_shift)));
if(cfg->baud > baud) {
diff_baud = cfg->baud - baud;
} else {
diff_baud = baud - cfg->baud;
}
if(cfg->baud > baud_1) {
diff_baud_1 = cfg->baud - baud_1;
} else {
diff_baud_1 = baud_1 - cfg->baud;
}
if(diff_baud < diff_baud_1) {
uart->baud = ((baud_div & MXC_F_UART_BAUD_BAUD_DIVISOR) |
(baud_shift << MXC_F_UART_BAUD_BAUD_MODE_POS));
} else {
uart->baud = (((baud_div+1) & MXC_F_UART_BAUD_BAUD_DIVISOR) |
(baud_shift << MXC_F_UART_BAUD_BAUD_MODE_POS));
}
return E_NO_ERROR;
}
/******************************************************************************/
int UART_Shutdown(mxc_uart_regs_t *uart)
{
int uart_num, err;
uart_req_t *temp_req;
uart_num = MXC_UART_GET_IDX(uart);
MXC_ASSERT(uart_num >= 0);
// Disable and clear interrupts
uart->inten = 0;
uart->intfl = uart->intfl;
// Disable UART and FIFOS
uart->ctrl &= ~(MXC_F_UART_CTRL_UART_EN | MXC_F_UART_CTRL_TX_FIFO_EN |
MXC_F_UART_CTRL_RX_FIFO_EN);
// Call all of the pending callbacks for this UART
if(rx_states[uart_num] != NULL) {
// Save the request
temp_req = rx_states[uart_num];
// Unlock this UART to read
mxc_free_lock((uint32_t*)&rx_states[uart_num]);
// Callback if not NULL
if(temp_req->callback != NULL) {
temp_req->callback(temp_req, E_SHUTDOWN);
}
}
if(tx_states[uart_num] != NULL) {
// Save the request
temp_req = tx_states[uart_num];
// Unlock this UART to write
mxc_free_lock((uint32_t*)&tx_states[uart_num]);
// Callback if not NULL
if(temp_req->callback != NULL) {
temp_req->callback(temp_req, E_SHUTDOWN);
}
}
// Clears system level configurations
if ((err = SYS_UART_Shutdown(uart)) != E_NO_ERROR) {
return err;
}
return E_NO_ERROR;
}
/******************************************************************************/
int UART_Write(mxc_uart_regs_t *uart, uint8_t* data, int len)
{
int num, uart_num;
mxc_uart_fifo_regs_t *fifo;
uart_num = MXC_UART_GET_IDX(uart);
MXC_ASSERT(uart_num >= 0);
if(data == NULL) {
return E_NULL_PTR;
}
// Make sure the UART has been initialized
if(!(uart->ctrl & MXC_F_UART_CTRL_UART_EN)) {
return E_UNINITIALIZED;
}
if(!(len > 0)) {
return E_NO_ERROR;
}
// Lock this UART from writing
while(mxc_get_lock((uint32_t*)&tx_states[uart_num], 1) != E_NO_ERROR) {}
// Get the FIFO for this UART
fifo = MXC_UART_GET_FIFO(uart_num);
num = 0;
while(num < len) {
// Wait for TXFIFO to not be full
while((uart->tx_fifo_ctrl & MXC_F_UART_TX_FIFO_CTRL_FIFO_ENTRY) ==
MXC_F_UART_TX_FIFO_CTRL_FIFO_ENTRY) {}
// Write the data to the FIFO
#if(MXC_UART_REV == 0)
uart->intfl = MXC_F_UART_INTFL_TX_DONE;
#endif
fifo->tx = data[num++];
}
// Unlock this UART to write
mxc_free_lock((uint32_t*)&tx_states[uart_num]);
return num;
}
/******************************************************************************/
int UART_Read(mxc_uart_regs_t *uart, uint8_t* data, int len, int *num)
{
int num_local, remain, uart_num;
mxc_uart_fifo_regs_t *fifo;
uart_num = MXC_UART_GET_IDX(uart);
MXC_ASSERT(uart_num >= 0);
if(data == NULL) {
return E_NULL_PTR;
}
// Make sure the UART has been initialized
if(!(uart->ctrl & MXC_F_UART_CTRL_UART_EN)) {
return E_UNINITIALIZED;
}
if(!(len > 0)) {
return E_NO_ERROR;
}
// Lock this UART from reading
while(mxc_get_lock((uint32_t*)&rx_states[uart_num], 1) != E_NO_ERROR) {}
// Get the FIFO for this UART
fifo = MXC_UART_GET_FIFO(uart_num);
num_local = 0;
remain = len;
while(remain) {
// Save the data in the FIFO
while((uart->rx_fifo_ctrl & MXC_F_UART_RX_FIFO_CTRL_FIFO_ENTRY) && remain) {
data[num_local] = fifo->rx;
num_local++;
remain--;
}
// Break if there is an error
if(uart->intfl & UART_ERRORS) {
break;
}
}
// Save the number of bytes read if pointer is valid
if(num != NULL) {
*num = num_local;
}
// Check for errors
if(uart->intfl & MXC_F_UART_INTFL_RX_FIFO_OVERFLOW) {
// Clear errors and return error code
uart->intfl = UART_ERRORS;
// Unlock this UART to read
mxc_free_lock((uint32_t*)&rx_states[uart_num]);
return E_OVERFLOW;
} else if(uart->intfl & (MXC_F_UART_INTFL_RX_FRAMING_ERR |
MXC_F_UART_INTFL_RX_PARITY_ERR)) {
// Clear errors and return error code
uart->intfl = UART_ERRORS;
// Unlock this UART to read
mxc_free_lock((uint32_t*)&rx_states[uart_num]);
return E_COMM_ERR;
}
// Unlock this UART to read
mxc_free_lock((uint32_t*)&rx_states[uart_num]);
return num_local;
}
/******************************************************************************/
int UART_WriteAsync(mxc_uart_regs_t *uart, uart_req_t *req)
{
int uart_num = MXC_UART_GET_IDX(uart);
MXC_ASSERT(uart_num >= 0);
// Check the input parameters
if(req->data == NULL) {
return E_NULL_PTR;
}
// Make sure the UART has been initialized
if(!(uart->ctrl & MXC_F_UART_CTRL_UART_EN)) {
return E_UNINITIALIZED;
}
if(!(req->len > 0)) {
return E_NO_ERROR;
}
// Attempt to register this write request
if(mxc_get_lock((uint32_t*)&tx_states[uart_num], (uint32_t)req) != E_NO_ERROR) {
return E_BUSY;
}
// Clear the number of bytes counter
req->num = 0;
// Start the write
UART_WriteHandler(uart, req, uart_num);
return E_NO_ERROR;
}
/******************************************************************************/
int UART_ReadAsync(mxc_uart_regs_t *uart, uart_req_t *req)
{
int uart_num;
uint32_t flags;
uart_num = MXC_UART_GET_IDX(uart);
MXC_ASSERT(uart_num >= 0);
if(req->data == NULL) {
return E_NULL_PTR;
}
// Make sure the UART has been initialized
if(!(uart->ctrl & MXC_F_UART_CTRL_UART_EN)) {
return E_UNINITIALIZED;
}
if(!(req->len > 0)) {
return E_NO_ERROR;
}
// Attempt to register this write request
if(mxc_get_lock((uint32_t*)&rx_states[uart_num], (uint32_t)req) != E_NO_ERROR) {
return E_BUSY;
}
// Clear the number of bytes counter
req->num = 0;
// Start the read
flags = uart->intfl;
uart->intfl = flags;
UART_ReadHandler(uart, req, uart_num, flags);
return E_NO_ERROR;
}
/******************************************************************************/
int UART_AbortAsync(uart_req_t *req)
{
int uart_num;
// Figure out if this was a read or write request, find the request, set to NULL
for(uart_num = 0; uart_num < MXC_CFG_UART_INSTANCES; uart_num++) {
if(req == rx_states[uart_num]) {
// Disable read interrupts, clear flags.
MXC_UART_GET_UART(uart_num)->inten &= ~UART_READ_INTS;
MXC_UART_GET_UART(uart_num)->intfl = UART_READ_INTS;
// Unlock this UART to read
mxc_free_lock((uint32_t*)&rx_states[uart_num]);
// Callback if not NULL
if(req->callback != NULL) {
req->callback(req, E_ABORT);
}
return E_NO_ERROR;
}
if(req == tx_states[uart_num]) {
// Disable write interrupts, clear flags.
MXC_UART_GET_UART(uart_num)->inten &= ~(UART_WRITE_INTS);
MXC_UART_GET_UART(uart_num)->intfl = UART_WRITE_INTS;
// Unlock this UART to write
mxc_free_lock((uint32_t*)&tx_states[uart_num]);
// Callback if not NULL
if(req->callback != NULL) {
req->callback(req, E_ABORT);
}
return E_NO_ERROR;
}
}
return E_BAD_PARAM;
}
/******************************************************************************/
void UART_Handler(mxc_uart_regs_t *uart)
{
int uart_num;
uint32_t flags;
uart_num = MXC_UART_GET_IDX(uart);
MXC_ASSERT(uart_num >= 0);
flags = uart->intfl;
uart->intfl = flags;
// Figure out if this UART has an active Read request
if((rx_states[uart_num] != NULL) && (flags & UART_READ_INTS)) {
UART_ReadHandler(uart, rx_states[uart_num], uart_num, flags);
}
// Figure out if this UART has an active Write request
if((tx_states[uart_num] != NULL) && (flags & (UART_WRITE_INTS))) {
UART_WriteHandler(uart, tx_states[uart_num], uart_num);
}
}
/******************************************************************************/
int UART_Busy(mxc_uart_regs_t *uart)
{
int uart_num = MXC_UART_GET_IDX(uart);
MXC_ASSERT(uart_num >= 0);
// Check to see if there are any ongoing transactions or if the UART is disabled
if(((tx_states[uart_num] == NULL) &&
!(uart->tx_fifo_ctrl & MXC_F_UART_TX_FIFO_CTRL_FIFO_ENTRY) &&
#if(MXC_UART_REV == 0)
(uart->intfl & MXC_F_UART_INTFL_TX_DONE)) ||
#else
(uart->idle & MXC_F_UART_IDLE_TX_RX_IDLE)) ||
#endif
!(uart->ctrl & MXC_F_UART_CTRL_UART_EN)) {
return E_NO_ERROR;
}
return E_BUSY;
}
/******************************************************************************/
int UART_PrepForSleep(mxc_uart_regs_t *uart)
{
if(UART_Busy(uart) != E_NO_ERROR) {
return E_BUSY;
}
// Leave read interrupts enabled, if already enabled
uart->inten &= UART_READ_INTS;
return E_NO_ERROR;
}
/******************************************************************************/
static void UART_WriteHandler(mxc_uart_regs_t *uart, uart_req_t *req, int uart_num)
{
int avail, remain;
mxc_uart_fifo_regs_t *fifo;
// Disable write interrupts
uart->inten &= ~(UART_WRITE_INTS);
// Get the FIFO for this UART
fifo = MXC_UART_GET_FIFO(uart_num);
// Refill the TX FIFO
avail = UART_NumWriteAvail(uart);
remain = req->len - req->num;
while(avail && remain) {
// Write the data to the FIFO
#if(MXC_UART_REV == 0)
uart->intfl = MXC_F_UART_INTFL_TX_DONE;
#endif
fifo->tx = req->data[req->num++];
remain--;
avail--;
}
// All of the bytes have been written to the FIFO
if(!remain) {
// Unlock this UART to write
mxc_free_lock((uint32_t*)&tx_states[uart_num]);
if(req->callback != NULL) {
req->callback(req, E_NO_ERROR);
}
} else {
// Interrupt when there is one byte left in the TXFIFO
uart->tx_fifo_ctrl = ((MXC_UART_FIFO_DEPTH - 1) << MXC_F_UART_TX_FIFO_CTRL_FIFO_AE_LVL_POS);
// Enable almost empty interrupt
uart->inten |= (MXC_F_UART_INTEN_TX_FIFO_AE);
}
}
/******************************************************************************/
static void UART_ReadHandler(mxc_uart_regs_t *uart, uart_req_t *req, int uart_num,
uint32_t flags)
{
int avail, remain;
mxc_uart_fifo_regs_t *fifo;
// Disable interrupts
uart->inten &= ~UART_READ_INTS;
// Get the FIFO for this UART, uart_num
fifo = MXC_UART_GET_FIFO(uart_num);
// Save the data in the FIFO while we still need data
avail = UART_NumReadAvail(uart);
remain = req->len - req->num;
while(avail && remain) {
req->data[req->num++] = fifo->rx;
remain--;
avail--;
}
// Check for errors
if(flags & MXC_F_UART_INTFL_RX_FIFO_OVERFLOW) {
// Unlock this UART to read
mxc_free_lock((uint32_t*)&rx_states[uart_num]);
if(req->callback != NULL) {
req->callback(req, E_OVERFLOW);
}
return;
}
if(flags & (MXC_F_UART_INTFL_RX_FRAMING_ERR |
MXC_F_UART_INTFL_RX_PARITY_ERR)) {
// Unlock this UART to read
mxc_free_lock((uint32_t*)&rx_states[uart_num]);
if(req->callback != NULL) {
req->callback(req, E_COMM_ERR);
}
return;
}
// Check to see if we're done receiving
if(remain == 0) {
// Unlock this UART to read
mxc_free_lock((uint32_t*)&rx_states[uart_num]);
if(req->callback != NULL) {
req->callback(req, E_NO_ERROR);
}
return;
}
if(remain == 1) {
uart->inten |= (MXC_F_UART_INTEN_RX_FIFO_NOT_EMPTY | UART_ERRORS);
} else {
// Set the RX FIFO AF threshold
if(remain < UART_RXFIFO_USABLE) {
uart->rx_fifo_ctrl = ((remain - 1) <<
MXC_F_UART_RX_FIFO_CTRL_FIFO_AF_LVL_POS);
} else {
uart->rx_fifo_ctrl = (UART_RXFIFO_USABLE <<
MXC_F_UART_RX_FIFO_CTRL_FIFO_AF_LVL_POS);
}
uart->inten |= (MXC_F_UART_INTEN_RX_FIFO_AF | UART_ERRORS);
}
}