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DFI/eigener_ctrl/stm32f407-olimex/chibios/os/hal/ports/STM32/LLD/MACv1/hal_mac_lld.c

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/*
ChibiOS - Copyright (C) 2006..2016 Giovanni Di Sirio
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
/**
* @file MACv1/hal_mac_lld.c
* @brief STM32 low level MAC driver code.
*
* @addtogroup MAC
* @{
*/
#include <string.h>
#include "hal.h"
#if HAL_USE_MAC || defined(__DOXYGEN__)
#include "hal_mii.h"
/*===========================================================================*/
/* Driver local definitions. */
/*===========================================================================*/
#define BUFFER_SIZE ((((STM32_MAC_BUFFERS_SIZE - 1) | 3) + 1) / 4)
/* Fixing inconsistencies in ST headers.*/
#if !defined(ETH_MACMIIAR_CR_Div102) && defined(ETH_MACMIIAR_CR_DIV102)
#define ETH_MACMIIAR_CR_Div102 ETH_MACMIIAR_CR_DIV102
#endif
#if !defined(ETH_MACMIIAR_CR_Div62) && defined(ETH_MACMIIAR_CR_DIV62)
#define ETH_MACMIIAR_CR_Div62 ETH_MACMIIAR_CR_DIV62
#endif
#if !defined(ETH_MACMIIAR_CR_Div42) && defined(ETH_MACMIIAR_CR_DIV42)
#define ETH_MACMIIAR_CR_Div42 ETH_MACMIIAR_CR_DIV42
#endif
#if !defined(ETH_MACMIIAR_CR_Div26) && defined(ETH_MACMIIAR_CR_DIV26)
#define ETH_MACMIIAR_CR_Div26 ETH_MACMIIAR_CR_DIV26
#endif
#if !defined(ETH_MACMIIAR_CR_Div16) && defined(ETH_MACMIIAR_CR_DIV16)
#define ETH_MACMIIAR_CR_Div16 ETH_MACMIIAR_CR_DIV16
#endif
/* MII divider optimal value.*/
#if (STM32_HCLK >= 150000000)
#define MACMIIDR_CR ETH_MACMIIAR_CR_Div102
#elif (STM32_HCLK >= 100000000)
#define MACMIIDR_CR ETH_MACMIIAR_CR_Div62
#elif (STM32_HCLK >= 60000000)
#define MACMIIDR_CR ETH_MACMIIAR_CR_Div42
#elif (STM32_HCLK >= 35000000)
#define MACMIIDR_CR ETH_MACMIIAR_CR_Div26
#elif (STM32_HCLK >= 20000000)
#define MACMIIDR_CR ETH_MACMIIAR_CR_Div16
#else
#error "STM32_HCLK below minimum frequency for ETH operations (20MHz)"
#endif
/*===========================================================================*/
/* Driver exported variables. */
/*===========================================================================*/
/**
* @brief Ethernet driver 1.
*/
MACDriver ETHD1;
/*===========================================================================*/
/* Driver local variables and types. */
/*===========================================================================*/
static const uint8_t default_mac_address[] = {0xAA, 0x55, 0x13,
0x37, 0x01, 0x10};
static stm32_eth_rx_descriptor_t __eth_rd[STM32_MAC_RECEIVE_BUFFERS];
static stm32_eth_tx_descriptor_t __eth_td[STM32_MAC_TRANSMIT_BUFFERS];
static uint32_t __eth_rb[STM32_MAC_RECEIVE_BUFFERS][BUFFER_SIZE];
static uint32_t __eth_tb[STM32_MAC_TRANSMIT_BUFFERS][BUFFER_SIZE];
/*===========================================================================*/
/* Driver local functions. */
/*===========================================================================*/
/**
* @brief Writes a PHY register.
*
* @param[in] macp pointer to the @p MACDriver object
* @param[in] reg register number
* @param[in] value new register value
*
* @notapi
*/
void mii_write(MACDriver *macp, uint32_t reg, uint32_t value) {
ETH->MACMIIDR = value;
ETH->MACMIIAR = macp->phyaddr | (reg << 6) | MACMIIDR_CR |
ETH_MACMIIAR_MW | ETH_MACMIIAR_MB;
while ((ETH->MACMIIAR & ETH_MACMIIAR_MB) != 0)
;
}
/**
* @brief Reads a PHY register.
*
* @param[in] macp pointer to the @p MACDriver object
* @param[in] reg register number
*
* @return The PHY register content.
*
* @notapi
*/
uint32_t mii_read(MACDriver *macp, uint32_t reg) {
ETH->MACMIIAR = macp->phyaddr | (reg << 6) | MACMIIDR_CR | ETH_MACMIIAR_MB;
while ((ETH->MACMIIAR & ETH_MACMIIAR_MB) != 0)
;
return ETH->MACMIIDR;
}
#if !defined(BOARD_PHY_ADDRESS)
/**
* @brief PHY address detection.
*
* @param[in] macp pointer to the @p MACDriver object
*/
static void mii_find_phy(MACDriver *macp) {
uint32_t i;
#if STM32_MAC_PHY_TIMEOUT > 0
unsigned n = STM32_MAC_PHY_TIMEOUT;
do {
#endif
for (i = 0U; i < 31U; i++) {
macp->phyaddr = i << 11U;
ETH->MACMIIDR = (i << 6U) | MACMIIDR_CR;
if ((mii_read(macp, MII_PHYSID1) == (BOARD_PHY_ID >> 16U)) &&
((mii_read(macp, MII_PHYSID2) & 0xFFF0U) == (BOARD_PHY_ID & 0xFFF0U))) {
return;
}
}
#if STM32_MAC_PHY_TIMEOUT > 0
n--;
} while (n > 0U);
#endif
/* Wrong or defective board.*/
osalSysHalt("MAC failure");
}
#endif
/**
* @brief MAC address setup.
*
* @param[in] p pointer to a six bytes buffer containing the MAC
* address
*/
static void mac_lld_set_address(const uint8_t *p) {
/* MAC address configuration, only a single address comparator is used,
hash table not used.*/
ETH->MACA0HR = ((uint32_t)p[5] << 8) |
((uint32_t)p[4] << 0);
ETH->MACA0LR = ((uint32_t)p[3] << 24) |
((uint32_t)p[2] << 16) |
((uint32_t)p[1] << 8) |
((uint32_t)p[0] << 0);
ETH->MACA1HR = 0x0000FFFF;
ETH->MACA1LR = 0xFFFFFFFF;
ETH->MACA2HR = 0x0000FFFF;
ETH->MACA2LR = 0xFFFFFFFF;
ETH->MACA3HR = 0x0000FFFF;
ETH->MACA3LR = 0xFFFFFFFF;
ETH->MACHTHR = 0;
ETH->MACHTLR = 0;
}
/*===========================================================================*/
/* Driver interrupt handlers. */
/*===========================================================================*/
OSAL_IRQ_HANDLER(STM32_ETH_HANDLER) {
uint32_t dmasr;
OSAL_IRQ_PROLOGUE();
dmasr = ETH->DMASR;
ETH->DMASR = dmasr; /* Clear status bits.*/
if (dmasr & ETH_DMASR_RS) {
/* Data Received.*/
osalSysLockFromISR();
osalThreadDequeueAllI(&ETHD1.rdqueue, MSG_RESET);
#if MAC_USE_EVENTS
osalEventBroadcastFlagsI(&ETHD1.rdevent, 0);
#endif
osalSysUnlockFromISR();
}
if (dmasr & ETH_DMASR_TS) {
/* Data Transmitted.*/
osalSysLockFromISR();
osalThreadDequeueAllI(&ETHD1.tdqueue, MSG_RESET);
osalSysUnlockFromISR();
}
OSAL_IRQ_EPILOGUE();
}
/*===========================================================================*/
/* Driver exported functions. */
/*===========================================================================*/
/**
* @brief Low level MAC initialization.
*
* @notapi
*/
void mac_lld_init(void) {
unsigned i;
macObjectInit(&ETHD1);
ETHD1.link_up = false;
/* Descriptor tables are initialized in chained mode, note that the first
word is not initialized here but in mac_lld_start().*/
for (i = 0; i < STM32_MAC_RECEIVE_BUFFERS; i++) {
__eth_rd[i].rdes1 = STM32_RDES1_RCH | STM32_MAC_BUFFERS_SIZE;
__eth_rd[i].rdes2 = (uint32_t)__eth_rb[i];
__eth_rd[i].rdes3 = (uint32_t)&__eth_rd[(i + 1) % STM32_MAC_RECEIVE_BUFFERS];
}
for (i = 0; i < STM32_MAC_TRANSMIT_BUFFERS; i++) {
__eth_td[i].tdes1 = 0;
__eth_td[i].tdes2 = (uint32_t)__eth_tb[i];
__eth_td[i].tdes3 = (uint32_t)&__eth_td[(i + 1) % STM32_MAC_TRANSMIT_BUFFERS];
}
/* Selection of the RMII or MII mode based on info exported by board.h.*/
#if defined(STM32F10X_CL)
#if defined(BOARD_PHY_RMII)
AFIO->MAPR |= AFIO_MAPR_MII_RMII_SEL;
#else
AFIO->MAPR &= ~AFIO_MAPR_MII_RMII_SEL;
#endif
#elif defined(STM32F2XX) || defined(STM32F4XX) || defined(STM32F7XX)
#if defined(BOARD_PHY_RMII)
SYSCFG->PMC |= SYSCFG_PMC_MII_RMII_SEL;
#else
SYSCFG->PMC &= ~SYSCFG_PMC_MII_RMII_SEL;
#endif
#else
#error "unsupported STM32 platform for MAC driver"
#endif
/* Reset of the MAC core.*/
rccResetETH();
/* MAC clocks temporary activation.*/
rccEnableETH(false);
/* PHY address setup.*/
#if defined(BOARD_PHY_ADDRESS)
ETHD1.phyaddr = 0 << 11;
#else
mii_find_phy(&ETHD1);
#endif
#if defined(BOARD_PHY_RESET)
/* PHY board-specific reset procedure.*/
BOARD_PHY_RESET();
#else
/* PHY soft reset procedure.*/
mii_write(&ETHD1, MII_BMCR, BMCR_RESET);
#if defined(BOARD_PHY_RESET_DELAY)
osalSysPolledDelayX(BOARD_PHY_RESET_DELAY);
#endif
while (mii_read(&ETHD1, MII_BMCR) & BMCR_RESET)
;
#endif
#if STM32_MAC_ETH1_CHANGE_PHY_STATE
/* PHY in power down mode until the driver will be started.*/
mii_write(&ETHD1, MII_BMCR, mii_read(&ETHD1, MII_BMCR) | BMCR_PDOWN);
#endif
/* MAC clocks stopped again.*/
rccDisableETH(false);
}
/**
* @brief Configures and activates the MAC peripheral.
*
* @param[in] macp pointer to the @p MACDriver object
*
* @notapi
*/
void mac_lld_start(MACDriver *macp) {
unsigned i;
/* Resets the state of all descriptors.*/
for (i = 0; i < STM32_MAC_RECEIVE_BUFFERS; i++)
__eth_rd[i].rdes0 = STM32_RDES0_OWN;
macp->rxptr = (stm32_eth_rx_descriptor_t *)__eth_rd;
for (i = 0; i < STM32_MAC_TRANSMIT_BUFFERS; i++)
__eth_td[i].tdes0 = STM32_TDES0_TCH;
macp->txptr = (stm32_eth_tx_descriptor_t *)__eth_td;
/* MAC clocks activation and commanded reset procedure.*/
rccEnableETH(false);
#if defined(STM32_MAC_DMABMR_SR)
ETH->DMABMR |= ETH_DMABMR_SR;
while(ETH->DMABMR & ETH_DMABMR_SR)
;
#endif
/* ISR vector enabled.*/
nvicEnableVector(STM32_ETH_NUMBER, STM32_MAC_ETH1_IRQ_PRIORITY);
#if STM32_MAC_ETH1_CHANGE_PHY_STATE
/* PHY in power up mode.*/
mii_write(macp, MII_BMCR, mii_read(macp, MII_BMCR) & ~BMCR_PDOWN);
#endif
/* MAC configuration.*/
ETH->MACFFR = 0;
ETH->MACFCR = 0;
ETH->MACVLANTR = 0;
/* MAC address setup.*/
if (macp->config->mac_address == NULL)
mac_lld_set_address(default_mac_address);
else
mac_lld_set_address(macp->config->mac_address);
/* Transmitter and receiver enabled.
Note that the complete setup of the MAC is performed when the link
status is detected.*/
#if STM32_MAC_IP_CHECKSUM_OFFLOAD
ETH->MACCR = ETH_MACCR_IPCO | ETH_MACCR_RE | ETH_MACCR_TE;
#else
ETH->MACCR = ETH_MACCR_RE | ETH_MACCR_TE;
#endif
/* DMA configuration:
Descriptor chains pointers.*/
ETH->DMARDLAR = (uint32_t)__eth_rd;
ETH->DMATDLAR = (uint32_t)__eth_td;
/* Enabling required interrupt sources.*/
ETH->DMASR = ETH->DMASR;
ETH->DMAIER = ETH_DMAIER_NISE | ETH_DMAIER_RIE | ETH_DMAIER_TIE;
/* DMA general settings.*/
ETH->DMABMR = ETH_DMABMR_AAB | ETH_DMABMR_RDP_1Beat | ETH_DMABMR_PBL_1Beat;
/* Transmit FIFO flush.*/
ETH->DMAOMR = ETH_DMAOMR_FTF;
while (ETH->DMAOMR & ETH_DMAOMR_FTF)
;
/* DMA final configuration and start.*/
ETH->DMAOMR = ETH_DMAOMR_DTCEFD | ETH_DMAOMR_RSF | ETH_DMAOMR_TSF |
ETH_DMAOMR_ST | ETH_DMAOMR_SR;
}
/**
* @brief Deactivates the MAC peripheral.
*
* @param[in] macp pointer to the @p MACDriver object
*
* @notapi
*/
void mac_lld_stop(MACDriver *macp) {
if (macp->state != MAC_STOP) {
#if STM32_MAC_ETH1_CHANGE_PHY_STATE
/* PHY in power down mode until the driver will be restarted.*/
mii_write(macp, MII_BMCR, mii_read(macp, MII_BMCR) | BMCR_PDOWN);
#endif
/* MAC and DMA stopped.*/
ETH->MACCR = 0;
ETH->DMAOMR = 0;
ETH->DMAIER = 0;
ETH->DMASR = ETH->DMASR;
/* MAC clocks stopped.*/
rccDisableETH(false);
/* ISR vector disabled.*/
nvicDisableVector(STM32_ETH_NUMBER);
}
}
/**
* @brief Returns a transmission descriptor.
* @details One of the available transmission descriptors is locked and
* returned.
*
* @param[in] macp pointer to the @p MACDriver object
* @param[out] tdp pointer to a @p MACTransmitDescriptor structure
* @return The operation status.
* @retval MSG_OK the descriptor has been obtained.
* @retval MSG_TIMEOUT descriptor not available.
*
* @notapi
*/
msg_t mac_lld_get_transmit_descriptor(MACDriver *macp,
MACTransmitDescriptor *tdp) {
stm32_eth_tx_descriptor_t *tdes;
if (!macp->link_up)
return MSG_TIMEOUT;
osalSysLock();
/* Get Current TX descriptor.*/
tdes = macp->txptr;
/* Ensure that descriptor isn't owned by the Ethernet DMA or locked by
another thread.*/
if (tdes->tdes0 & (STM32_TDES0_OWN | STM32_TDES0_LOCKED)) {
osalSysUnlock();
return MSG_TIMEOUT;
}
/* Marks the current descriptor as locked using a reserved bit.*/
tdes->tdes0 |= STM32_TDES0_LOCKED;
/* Next TX descriptor to use.*/
macp->txptr = (stm32_eth_tx_descriptor_t *)tdes->tdes3;
osalSysUnlock();
/* Set the buffer size and configuration.*/
tdp->offset = 0;
tdp->size = STM32_MAC_BUFFERS_SIZE;
tdp->physdesc = tdes;
return MSG_OK;
}
/**
* @brief Releases a transmit descriptor and starts the transmission of the
* enqueued data as a single frame.
*
* @param[in] tdp the pointer to the @p MACTransmitDescriptor structure
*
* @notapi
*/
void mac_lld_release_transmit_descriptor(MACTransmitDescriptor *tdp) {
osalDbgAssert(!(tdp->physdesc->tdes0 & STM32_TDES0_OWN),
"attempt to release descriptor already owned by DMA");
osalSysLock();
/* Unlocks the descriptor and returns it to the DMA engine.*/
tdp->physdesc->tdes1 = tdp->offset;
tdp->physdesc->tdes0 = STM32_TDES0_CIC(STM32_MAC_IP_CHECKSUM_OFFLOAD) |
STM32_TDES0_IC | STM32_TDES0_LS | STM32_TDES0_FS |
STM32_TDES0_TCH | STM32_TDES0_OWN;
/* Wait for the write to tdes0 to go through before resuming the DMA.*/
__DSB();
/* If the DMA engine is stalled then a restart request is issued.*/
if ((ETH->DMASR & ETH_DMASR_TPS) == ETH_DMASR_TPS_Suspended) {
ETH->DMASR = ETH_DMASR_TBUS;
ETH->DMATPDR = ETH_DMASR_TBUS; /* Any value is OK.*/
}
osalSysUnlock();
}
/**
* @brief Returns a receive descriptor.
*
* @param[in] macp pointer to the @p MACDriver object
* @param[out] rdp pointer to a @p MACReceiveDescriptor structure
* @return The operation status.
* @retval MSG_OK the descriptor has been obtained.
* @retval MSG_TIMEOUT descriptor not available.
*
* @notapi
*/
msg_t mac_lld_get_receive_descriptor(MACDriver *macp,
MACReceiveDescriptor *rdp) {
stm32_eth_rx_descriptor_t *rdes;
osalSysLock();
/* Get Current RX descriptor.*/
rdes = macp->rxptr;
/* Iterates through received frames until a valid one is found, invalid
frames are discarded.*/
while (!(rdes->rdes0 & STM32_RDES0_OWN)) {
if (!(rdes->rdes0 & (STM32_RDES0_AFM | STM32_RDES0_ES))
#if STM32_MAC_IP_CHECKSUM_OFFLOAD
&& (rdes->rdes0 & STM32_RDES0_FT)
&& !(rdes->rdes0 & (STM32_RDES0_IPHCE | STM32_RDES0_PCE))
#endif
&& (rdes->rdes0 & STM32_RDES0_FS) && (rdes->rdes0 & STM32_RDES0_LS)) {
/* Found a valid one.*/
rdp->offset = 0;
rdp->size = ((rdes->rdes0 & STM32_RDES0_FL_MASK) >> 16) - 4;
rdp->physdesc = rdes;
macp->rxptr = (stm32_eth_rx_descriptor_t *)rdes->rdes3;
osalSysUnlock();
return MSG_OK;
}
/* Invalid frame found, purging.*/
rdes->rdes0 = STM32_RDES0_OWN;
rdes = (stm32_eth_rx_descriptor_t *)rdes->rdes3;
}
/* Next descriptor to check.*/
macp->rxptr = rdes;
osalSysUnlock();
return MSG_TIMEOUT;
}
/**
* @brief Releases a receive descriptor.
* @details The descriptor and its buffer are made available for more incoming
* frames.
*
* @param[in] rdp the pointer to the @p MACReceiveDescriptor structure
*
* @notapi
*/
void mac_lld_release_receive_descriptor(MACReceiveDescriptor *rdp) {
osalDbgAssert(!(rdp->physdesc->rdes0 & STM32_RDES0_OWN),
"attempt to release descriptor already owned by DMA");
osalSysLock();
/* Give buffer back to the Ethernet DMA.*/
rdp->physdesc->rdes0 = STM32_RDES0_OWN;
/* Wait for the write to rdes0 to go through before resuming the DMA.*/
__DSB();
/* If the DMA engine is stalled then a restart request is issued.*/
if ((ETH->DMASR & ETH_DMASR_RPS) == ETH_DMASR_RPS_Suspended) {
ETH->DMASR = ETH_DMASR_RBUS;
ETH->DMARPDR = ETH_DMASR_RBUS; /* Any value is OK.*/
}
osalSysUnlock();
}
/**
* @brief Updates and returns the link status.
*
* @param[in] macp pointer to the @p MACDriver object
* @return The link status.
* @retval true if the link is active.
* @retval false if the link is down.
*
* @notapi
*/
bool mac_lld_poll_link_status(MACDriver *macp) {
uint32_t maccr, bmsr, bmcr;
maccr = ETH->MACCR;
/* PHY CR and SR registers read.*/
(void)mii_read(macp, MII_BMSR);
bmsr = mii_read(macp, MII_BMSR);
bmcr = mii_read(macp, MII_BMCR);
/* Check on auto-negotiation mode.*/
if (bmcr & BMCR_ANENABLE) {
uint32_t lpa;
/* Auto-negotiation must be finished without faults and link established.*/
if ((bmsr & (BMSR_LSTATUS | BMSR_RFAULT | BMSR_ANEGCOMPLETE)) !=
(BMSR_LSTATUS | BMSR_ANEGCOMPLETE))
return macp->link_up = false;
/* Auto-negotiation enabled, checks the LPA register.*/
lpa = mii_read(macp, MII_LPA);
/* Check on link speed.*/
if (lpa & (LPA_100HALF | LPA_100FULL | LPA_100BASE4))
maccr |= ETH_MACCR_FES;
else
maccr &= ~ETH_MACCR_FES;
/* Check on link mode.*/
if (lpa & (LPA_10FULL | LPA_100FULL))
maccr |= ETH_MACCR_DM;
else
maccr &= ~ETH_MACCR_DM;
}
else {
/* Link must be established.*/
if (!(bmsr & BMSR_LSTATUS))
return macp->link_up = false;
/* Check on link speed.*/
if (bmcr & BMCR_SPEED100)
maccr |= ETH_MACCR_FES;
else
maccr &= ~ETH_MACCR_FES;
/* Check on link mode.*/
if (bmcr & BMCR_FULLDPLX)
maccr |= ETH_MACCR_DM;
else
maccr &= ~ETH_MACCR_DM;
}
/* Changes the mode in the MAC.*/
ETH->MACCR = maccr;
/* Returns the link status.*/
return macp->link_up = true;
}
/**
* @brief Writes to a transmit descriptor's stream.
*
* @param[in] tdp pointer to a @p MACTransmitDescriptor structure
* @param[in] buf pointer to the buffer containing the data to be
* written
* @param[in] size number of bytes to be written
* @return The number of bytes written into the descriptor's
* stream, this value can be less than the amount
* specified in the parameter @p size if the maximum
* frame size is reached.
*
* @notapi
*/
size_t mac_lld_write_transmit_descriptor(MACTransmitDescriptor *tdp,
uint8_t *buf,
size_t size) {
osalDbgAssert(!(tdp->physdesc->tdes0 & STM32_TDES0_OWN),
"attempt to write descriptor already owned by DMA");
if (size > tdp->size - tdp->offset)
size = tdp->size - tdp->offset;
if (size > 0) {
memcpy((uint8_t *)(tdp->physdesc->tdes2) + tdp->offset, buf, size);
tdp->offset += size;
}
return size;
}
/**
* @brief Reads from a receive descriptor's stream.
*
* @param[in] rdp pointer to a @p MACReceiveDescriptor structure
* @param[in] buf pointer to the buffer that will receive the read data
* @param[in] size number of bytes to be read
* @return The number of bytes read from the descriptor's
* stream, this value can be less than the amount
* specified in the parameter @p size if there are
* no more bytes to read.
*
* @notapi
*/
size_t mac_lld_read_receive_descriptor(MACReceiveDescriptor *rdp,
uint8_t *buf,
size_t size) {
osalDbgAssert(!(rdp->physdesc->rdes0 & STM32_RDES0_OWN),
"attempt to read descriptor already owned by DMA");
if (size > rdp->size - rdp->offset)
size = rdp->size - rdp->offset;
if (size > 0) {
memcpy(buf, (uint8_t *)(rdp->physdesc->rdes2) + rdp->offset, size);
rdp->offset += size;
}
return size;
}
#if MAC_USE_ZERO_COPY || defined(__DOXYGEN__)
/**
* @brief Returns a pointer to the next transmit buffer in the descriptor
* chain.
* @note The API guarantees that enough buffers can be requested to fill
* a whole frame.
*
* @param[in] tdp pointer to a @p MACTransmitDescriptor structure
* @param[in] size size of the requested buffer. Specify the frame size
* on the first call then scale the value down subtracting
* the amount of data already copied into the previous
* buffers.
* @param[out] sizep pointer to variable receiving the buffer size, it is
* zero when the last buffer has already been returned.
* Note that a returned size lower than the amount
* requested means that more buffers must be requested
* in order to fill the frame data entirely.
* @return Pointer to the returned buffer.
* @retval NULL if the buffer chain has been entirely scanned.
*
* @notapi
*/
uint8_t *mac_lld_get_next_transmit_buffer(MACTransmitDescriptor *tdp,
size_t size,
size_t *sizep) {
if (tdp->offset == 0) {
*sizep = tdp->size;
tdp->offset = size;
return (uint8_t *)tdp->physdesc->tdes2;
}
*sizep = 0;
return NULL;
}
/**
* @brief Returns a pointer to the next receive buffer in the descriptor
* chain.
* @note The API guarantees that the descriptor chain contains a whole
* frame.
*
* @param[in] rdp pointer to a @p MACReceiveDescriptor structure
* @param[out] sizep pointer to variable receiving the buffer size, it is
* zero when the last buffer has already been returned.
* @return Pointer to the returned buffer.
* @retval NULL if the buffer chain has been entirely scanned.
*
* @notapi
*/
const uint8_t *mac_lld_get_next_receive_buffer(MACReceiveDescriptor *rdp,
size_t *sizep) {
if (rdp->size > 0) {
*sizep = rdp->size;
rdp->offset = rdp->size;
rdp->size = 0;
return (uint8_t *)rdp->physdesc->rdes2;
}
*sizep = 0;
return NULL;
}
#endif /* MAC_USE_ZERO_COPY */
#endif /* HAL_USE_MAC */
/** @} */
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