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gex-core/units/usart/_usart_dmas.c

444 lines
14 KiB

//
// Created by MightyPork on 2018/01/14.
//
#include "platform.h"
#include "irq_dispatcher.h"
#include "unit_base.h"
#define UUSART_INTERNAL
#include "_usart_internal.h"
static void UUSART_DMA_RxHandler(void *arg);
static void UUSART_DMA_TxHandler(void *arg);
#if UUSART_DEBUG
#define dbg_uusart(fmt, ...) dbg(fmt, ##__VA_ARGS__)
#else
#define dbg_uusart(fmt, ...)
#endif
error_t UUSART_ClaimDMAs(Unit *unit)
{
error_t rv;
assert_param(unit);
struct priv *priv = unit->data;
assert_param(priv);
priv->dma = DMA1;
switch (priv->periph_num) {
/* USART1 */
case 1:
// TX
rv = rsc_claim(unit, R_DMA1_2);
if (rv == E_SUCCESS) {
LL_SYSCFG_SetRemapDMA_USART(LL_SYSCFG_USART1TX_RMP_DMA1CH2);
priv->dma_tx = DMA1_Channel2;
priv->dma_tx_chnum = 2;
} else {
// try the remap
TRY(rsc_claim(unit, R_DMA1_4));
LL_SYSCFG_SetRemapDMA_USART(LL_SYSCFG_USART1TX_RMP_DMA1CH4);
priv->dma_tx = DMA1_Channel4;
priv->dma_tx_chnum = 4;
}
// RX
rv = rsc_claim(unit, R_DMA1_3);
if (rv == E_SUCCESS) {
LL_SYSCFG_SetRemapDMA_USART(LL_SYSCFG_USART1RX_RMP_DMA1CH3);
priv->dma_rx = DMA1_Channel3;
priv->dma_rx_chnum = 3;
} else {
// try the remap
TRY(rsc_claim(unit, R_DMA1_5));
LL_SYSCFG_SetRemapDMA_USART(LL_SYSCFG_USART1RX_RMP_DMA1CH5);
priv->dma_rx = DMA1_Channel5;
priv->dma_rx_chnum = 5;
}
break;
/* USART2 */
case 2:
// RX,TX
rv = rsc_claim_range(unit, R_DMA1_4, R_DMA1_5);
if (rv == E_SUCCESS) {
LL_SYSCFG_SetRemapDMA_USART(LL_SYSCFG_USART2_RMP_DMA1CH54);
priv->dma_tx = DMA1_Channel4;
priv->dma_rx = DMA1_Channel5;
priv->dma_tx_chnum = 4;
priv->dma_rx_chnum = 5;
} else {
// try the remap
TRY(rsc_claim_range(unit, R_DMA1_6, R_DMA1_7));
LL_SYSCFG_SetRemapDMA_USART(LL_SYSCFG_USART2_RMP_DMA1CH67);
priv->dma_tx = DMA1_Channel7;
priv->dma_rx = DMA1_Channel6;
priv->dma_tx_chnum = 7;
priv->dma_rx_chnum = 6;
}
break;
/* USART3 */
case 3:
// RX,TX
rv = rsc_claim_range(unit, R_DMA1_6, R_DMA1_7);
if (rv == E_SUCCESS) {
LL_SYSCFG_SetRemapDMA_USART(LL_SYSCFG_USART3_RMP_DMA1CH67);
priv->dma_tx = DMA1_Channel7;
priv->dma_rx = DMA1_Channel6;
priv->dma_tx_chnum = 7;
priv->dma_rx_chnum = 6;
} else {
// try the remap
TRY(rsc_claim_range(unit, R_DMA1_2, R_DMA1_3));
LL_SYSCFG_SetRemapDMA_USART(LL_SYSCFG_USART3_RMP_DMA1CH32);
priv->dma_tx = DMA1_Channel2;
priv->dma_rx = DMA1_Channel3;
priv->dma_tx_chnum = 2;
priv->dma_rx_chnum = 3;
}
break;
/* USART4 */
case 4:
// RX,TX
TRY(rsc_claim_range(unit, R_DMA1_6, R_DMA1_7));
priv->dma_tx = DMA1_Channel7;
priv->dma_rx = DMA1_Channel6;
priv->dma_tx_chnum = 7;
priv->dma_rx_chnum = 6;
break;
default:
trap("Missing DMA mapping for USART%d", (int)priv->periph_num);
}
dbg_uusart("USART %d - selected DMA ch Tx(%d), Rx(%d)", priv->periph_num, priv->dma_tx_chnum, priv->dma_rx_chnum);
return E_SUCCESS;
}
error_t UUSART_SetupDMAs(Unit *unit)
{
assert_param(unit);
struct priv *priv = unit->data;
assert_param(priv);
priv->rx_buffer = malloc_ck(UUSART_RXBUF_LEN);
if (NULL == priv->rx_buffer) return E_OUT_OF_MEM;
priv->tx_buffer = malloc_ck(UUSART_TXBUF_LEN);
if (NULL == priv->tx_buffer) return E_OUT_OF_MEM;
// Those must be aligned to a word boundary for the DMAs to work.
// Any well-behaved malloc impl should do this correctly.
assert_param(((uint32_t)priv->rx_buffer & 3) == 0);
assert_param(((uint32_t)priv->tx_buffer & 3) == 0);
priv->rx_buf_readpos = 0;
LL_DMA_InitTypeDef init;
// Transmit buffer
{
LL_DMA_StructInit(&init);
init.Direction = LL_DMA_DIRECTION_MEMORY_TO_PERIPH;
init.Mode = LL_DMA_MODE_NORMAL;
init.PeriphOrM2MSrcAddress = (uint32_t) &priv->periph->TDR;
init.PeriphOrM2MSrcDataSize = LL_DMA_PDATAALIGN_BYTE;
init.PeriphOrM2MSrcIncMode = LL_DMA_PERIPH_NOINCREMENT;
init.MemoryOrM2MDstAddress = (uint32_t) priv->tx_buffer;
init.MemoryOrM2MDstDataSize = LL_DMA_MDATAALIGN_BYTE;
init.MemoryOrM2MDstIncMode = LL_DMA_MEMORY_INCREMENT;
assert_param(SUCCESS == LL_DMA_Init(priv->dma, priv->dma_tx_chnum, &init));
irqd_attach(priv->dma_tx, UUSART_DMA_TxHandler, unit);
// Interrupt on transfer complete
LL_DMA_EnableIT_TC(priv->dma, priv->dma_tx_chnum);
}
// Receive buffer
{
LL_DMA_StructInit(&init);
init.Direction = LL_DMA_DIRECTION_PERIPH_TO_MEMORY;
init.Mode = LL_DMA_MODE_CIRCULAR;
init.NbData = UUSART_RXBUF_LEN;
init.PeriphOrM2MSrcAddress = (uint32_t) &priv->periph->RDR;
init.PeriphOrM2MSrcDataSize = LL_DMA_PDATAALIGN_BYTE;
init.PeriphOrM2MSrcIncMode = LL_DMA_PERIPH_NOINCREMENT;
init.MemoryOrM2MDstAddress = (uint32_t) priv->rx_buffer;
init.MemoryOrM2MDstDataSize = LL_DMA_MDATAALIGN_BYTE;
init.MemoryOrM2MDstIncMode = LL_DMA_MEMORY_INCREMENT;
assert_param(SUCCESS == LL_DMA_Init(priv->dma, priv->dma_rx_chnum, &init));
irqd_attach(priv->dma_rx, UUSART_DMA_RxHandler, unit);
// Interrupt on transfer 1/2 and complete
// We will capture the first and second half and send it while the other half is being filled.
LL_DMA_EnableIT_HT(priv->dma, priv->dma_rx_chnum);
LL_DMA_EnableIT_TC(priv->dma, priv->dma_rx_chnum);
}
LL_DMA_EnableChannel(priv->dma, priv->dma_rx_chnum);
LL_DMA_EnableChannel(priv->dma, priv->dma_tx_chnum);
return E_SUCCESS;
}
/**
* Handler for the Rx DMA half or full interrupt
* @param arg - unit instance
*/
static void UUSART_DMA_RxHandler(void *arg)
{
Unit *unit = arg;
assert_param(unit);
struct priv *priv = unit->data;
assert_param(priv);
const uint32_t isrsnapshot = priv->dma->ISR;
if (LL_DMA_IsActiveFlag_G(isrsnapshot, priv->dma_rx_chnum)) {
bool tc = LL_DMA_IsActiveFlag_TC(isrsnapshot, priv->dma_rx_chnum);
bool ht = LL_DMA_IsActiveFlag_HT(isrsnapshot, priv->dma_rx_chnum);
// Here we have to either copy it somewhere else, or notify another thread (queue?)
// that the data is ready for reading
if (ht) {
uint16_t end = (uint16_t) UUSART_RXBUF_LEN / 2;
UUSART_DMA_HandleRxFromIRQ(unit, end);
LL_DMA_ClearFlag_HT(priv->dma, priv->dma_rx_chnum);
}
if (tc) {
uint16_t end = (uint16_t) UUSART_RXBUF_LEN;
UUSART_DMA_HandleRxFromIRQ(unit, end);
LL_DMA_ClearFlag_TC(priv->dma, priv->dma_rx_chnum);
}
if (LL_DMA_IsActiveFlag_TE(isrsnapshot, priv->dma_rx_chnum)) {
// this shouldn't happen
dbg("USART DMA TE!");
LL_DMA_ClearFlag_TE(priv->dma, priv->dma_rx_chnum);
}
}
}
/**
* Start sending a chunk of data.
* This must be called when the DMA is completed.
*
* @param priv
*/
static void UUSART_DMA_TxStart(struct priv *priv)
{
priv->tx_dma_busy = true;
assert_param(priv->dma_tx->CNDTR == 0);
dbg_uusart("DMA_TxStart (nr %d, nw %d)", (int)priv->tx_buf_nr, (int)priv->tx_buf_nw);
uint16_t nr = priv->tx_buf_nr;
uint16_t nw = priv->tx_buf_nw;
if (nr == nw) {
dbg_uusart("remain=0,do nothing");
return;
} // do nothing if we're done
uint8_t chunk = priv->tx_buffer[nr++];
//nr += (uint16_t) (4 - (nr & 0b11));
if (chunk == 0) {
// wrap-around
chunk = priv->tx_buffer[0];
nr = 1;
assert_param(nr < nw);
}
// nr was advanced by the lpad preamble
priv->tx_buf_nr = nr;
priv->tx_buf_chunk = chunk; // will be further moved by 'chunk' bytes when dma completes
dbg_uusart("# TX: chunk start %d, len %d", (int)nr, (int)chunk);
//#if UUSART_DEBUG
// PUTS(">"); PUTSN((char *) (priv->tx_buffer + nr), chunk); PUTS("<");
// PUTNL();
//#endif
LL_DMA_DisableChannel(priv->dma, priv->dma_tx_chnum);
{
LL_DMA_ClearFlags(priv->dma, priv->dma_tx_chnum);
LL_DMA_SetMemoryAddress(priv->dma, priv->dma_tx_chnum, (uint32_t) (priv->tx_buffer + nr));
LL_DMA_SetDataLength(priv->dma, priv->dma_tx_chnum, chunk);
LL_USART_ClearFlag_TC(priv->periph);
}
LL_DMA_EnableChannel(priv->dma, priv->dma_tx_chnum);
}
COMPILER_ASSERT(UUSART_TXBUF_LEN <= 256); // more would break the "len tag" algorithm
/**
* Put data on the queue. Only a part may be sent due to a buffer size limit.
*
* @param priv
* @param buffer - buffer to send
* @param len - buffer size
* @return number of bytes that were really written (from the beginning)
*/
uint16_t UUSART_DMA_TxQueue(struct priv *priv, const uint8_t *buffer, uint16_t len)
{
const uint16_t nr = priv->tx_buf_nr;
uint16_t nw = priv->tx_buf_nw;
// shortcut for checking a completely full buffer
if (nw == nr-1 || (nr==0&&nw==UUSART_TXBUF_LEN-1)) {
dbg_uusart("Buffer full, cant queue");
return 0;
}
dbg_uusart("\r\nQueue..");
uint16_t used = 0;
if (nr == nw) {
used = 0;
} else if (nw > nr) { // simple linear
used = (uint16_t) (nw - nr);
} else if (nw < nr) { // wrapped
used = (uint16_t) ((UUSART_TXBUF_LEN - nr) + nw);
}
dbg_uusart("Trying to send buffer of len %d", (int)len);
uint16_t avail = (const uint16_t) (UUSART_TXBUF_LEN - 1 - used);
dbg_uusart("nr %d, nw %d, used %d, avail %d", (int)nr, (int)nw, (int)used, (int)avail);
// hack to avoid too large chunks (we use 1 byte to store chunk size)
if (avail > 255) avail = 255;
uint8_t written = 0;
// this avoids attempting to write if we don't have space
if (avail <= 5) {
dbg_uusart("No space (only %d)", (int) avail);
return written;
}
int cnt = 0;
while (avail > 0 && written < len) {
assert_param(cnt < 2); // if more than two, we have a bug and it's repeating infinitely
cnt++;
// Padding with chunk information (1 byte: length) - for each chunk
const uint8_t lpad = 1;
// Chunk can go max to the end of the buffer
uint8_t chunk = (uint8_t) MIN((len-written) + lpad, UUSART_TXBUF_LEN - nw);
if (chunk > avail) chunk = (uint8_t) avail;
dbg_uusart("nw %d, raw available chunk %d", (int) nw, (int)chunk);
if (chunk < lpad + 1) {
// write 0 to indicate a wrap-around
dbg_uusart("Wrap-around marker at offset %d", (int) nw);
priv->tx_buffer[nw] = 0;
nw = 0;
}
else {
// enough space for a preamble + some data
dbg_uusart("Preamble of %d bytes at offset %d", (int) lpad, (int) nw);
priv->tx_buffer[nw] = (uint8_t) (chunk - lpad);
nw += lpad;
uint8_t datachunk = (uint8_t) (chunk - lpad);
dbg_uusart("Datachunk len %d at offset %d", (int) datachunk, (int) nw);
//#if UUSART_DEBUG
// PUTS("mcpy src >"); PUTSN((char *) (buffer), datachunk); PUTS("<\r\n");
//#endif
memcpy((uint8_t *) (priv->tx_buffer + nw), buffer, datachunk);
//#if UUSART_DEBUG
// PUTS("mcpy dst >"); PUTSN((char *) (priv->tx_buffer + nw), datachunk); PUTS("<\r\n");
//#endif
buffer += datachunk;
nw += datachunk;
written += datachunk;
if (nw == UUSART_TXBUF_LEN) nw = 0;
}
avail -= chunk;
dbg_uusart(". end of loop, avail is %d", (int)avail);
}
{
dbg_uusart("Write done -> nr %d, nw %d", (int) nr, (int) nw);
// FIXME a potential race condition can happen here (but it's unlikely)
priv->tx_buf_nw = nw;
if (!priv->tx_dma_busy) {
dbg_uusart("Write done, requesting DMA.");
UUSART_DMA_TxStart(priv);
}
else {
dbg_uusart("DMA in progress, not requesting");
}
}
return written;
}
/**
* Handler for the Tx DMA - completion interrupt
* @param arg - unit instance
*/
static void UUSART_DMA_TxHandler(void *arg)
{
Unit *unit = arg;
assert_param(unit);
struct priv *priv = unit->data;
assert_param(priv);
uint32_t isrsnapshot = priv->dma->ISR;
if (LL_DMA_IsActiveFlag_TC(isrsnapshot, priv->dma_tx_chnum)) {
// chunk Tx is finished
dbg_uusart("~ DMA tx done, nr %d, nw %d, chunk %d", (int)priv->tx_buf_nr, (int)priv->tx_buf_nw, (int)priv->tx_buf_chunk);
priv->tx_buf_nr += priv->tx_buf_chunk;
if (UUSART_TXBUF_LEN == priv->tx_buf_nr) priv->tx_buf_nr = 0;
priv->tx_buf_chunk = 0;
LL_DMA_ClearFlag_TC(priv->dma, priv->dma_tx_chnum);
// Wait for TC
while (!LL_USART_IsActiveFlag_TC(priv->periph)); // TODO timeout
// start the next chunk
if (priv->tx_buf_nr != priv->tx_buf_nw) {
dbg_uusart(" Asking for more, if any");
UUSART_DMA_TxStart(priv);
} else {
priv->tx_dma_busy = false;
}
}
}
void UUSART_DeInitDMAs(Unit *unit)
{
assert_param(unit);
struct priv *priv = unit->data;
assert_param(priv);
irqd_detach(priv->dma_tx, UUSART_DMA_TxHandler);
irqd_detach(priv->dma_rx, UUSART_DMA_RxHandler);
LL_DMA_DeInit(priv->dma, priv->dma_rx_chnum);
LL_DMA_DeInit(priv->dma, priv->dma_tx_chnum);
free_ck(priv->rx_buffer);
free_ck(priv->tx_buffer);
}