Crash_Override/OVMS3-idf
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

spi_slave: add valid check for DMA buffers

Browse source 
The DMA cannot receive data correctly when the buffer address is not
WORD aligned. Currently we only check whether the buffer is in the DRAM
region.

The DMA always write in WORDs, so the length arguments should also be
multiples of 32 bits.

A check is added to see whether the buffer is WORD aligned and has valid
length.
This commit is contained in:
michael 2018-11-20 11:13:44 +08:00 committed by bot
parent 435adaa22a
commit cfba157fdd
5 changed files with 40 additions and 20 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
components/driver/include/driver/spi_slave.h
View file

@ -73,7 +73,10 @@ struct spi_slave_transaction_t {
size_t length; ///< Total data length, in bits
size_t trans_len; ///< Transaction data length, in bits
const void *tx_buffer; ///< Pointer to transmit buffer, or NULL for no MOSI phase
void *rx_buffer; ///< Pointer to receive buffer, or NULL for no MISO phase
void *rx_buffer; /**< Pointer to receive buffer, or NULL for no MISO phase.
* When the DMA is anabled, must start at WORD boundary (``rx_buffer%4==0``),
* and has length of a multiple of 4 bytes.
*/
void *user; ///< User-defined variable. Can be used to store eg transaction ID.
};

6
components/driver/spi_slave.c
View file

@ -298,8 +298,10 @@ esp_err_t SPI_SLAVE_ATTR spi_slave_queue_trans(spi_host_device_t host, const spi
SPI_CHECK(spihost[host], "host not slave", ESP_ERR_INVALID_ARG);
SPI_CHECK(spihost[host]->dma_chan == 0 || trans_desc->tx_buffer==NULL || esp_ptr_dma_capable(trans_desc->tx_buffer),
"txdata not in DMA-capable memory", ESP_ERR_INVALID_ARG);
SPI_CHECK(spihost[host]->dma_chan == 0 || trans_desc->rx_buffer==NULL || esp_ptr_dma_capable(trans_desc->rx_buffer),
"rxdata not in DMA-capable memory", ESP_ERR_INVALID_ARG);
SPI_CHECK(spihost[host]->dma_chan == 0 || trans_desc->rx_buffer==NULL ||
(esp_ptr_dma_capable(trans_desc->rx_buffer) && esp_ptr_word_aligned(trans_desc->rx_buffer) &&
(trans_desc->length%4==0)),
"rxdata not in DMA-capable memory or not WORD aligned", ESP_ERR_INVALID_ARG);
SPI_CHECK(trans_desc->length <= spihost[host]->max_transfer_sz * 8, "data transfer > host maximum", ESP_ERR_INVALID_ARG);
r = xQueueSend(spihost[host]->trans_queue, (void *)&trans_desc, ticks_to_wait);

14
components/driver/test/test_spi_slave.c
View file

@ -78,12 +78,12 @@ static void slave_init()
TEST_ESP_OK( spi_slave_initialize(VSPI_HOST, &buscfg, &slvcfg, 2) );
}
TEST_CASE("test slave startup","[spi]")
TEST_CASE("test slave send unaligned","[spi]")
{
uint8_t master_txbuf[320]=MASTER_SEND;
uint8_t master_rxbuf[320];
uint8_t slave_txbuf[320]=SLAVE_SEND;
uint8_t slave_rxbuf[320];
WORD_ALIGNED_ATTR uint8_t master_txbuf[320]=MASTER_SEND;
WORD_ALIGNED_ATTR uint8_t master_rxbuf[320];
WORD_ALIGNED_ATTR uint8_t slave_txbuf[320]=SLAVE_SEND;
WORD_ALIGNED_ATTR uint8_t slave_rxbuf[320];
spi_device_handle_t spi;
//initial master
@ -97,13 +97,13 @@ TEST_CASE("test slave startup","[spi]")
int_connect( PIN_NUM_CS, HSPICS0_OUT_IDX, VSPICS0_IN_IDX );
int_connect( PIN_NUM_CLK, HSPICLK_OUT_IDX, VSPICLK_IN_IDX );
for ( int i = 0; i < 3; i ++ ) {
for ( int i = 0; i < 4; i ++ ) {
//slave send
spi_slave_transaction_t slave_t;
spi_slave_transaction_t* out;
memset(&slave_t, 0, sizeof(spi_slave_transaction_t));
slave_t.length=8*32;
slave_t.tx_buffer=slave_txbuf+2*i;
slave_t.tx_buffer=slave_txbuf+i;
slave_t.rx_buffer=slave_rxbuf;
TEST_ESP_OK( spi_slave_queue_trans( VSPI_HOST, &slave_t, portMAX_DELAY ) );

5
components/soc/include/soc/soc_memory_layout.h
View file

@ -144,6 +144,11 @@ inline static bool IRAM_ATTR esp_ptr_dma_capable(const void *p)
return (intptr_t)p >= SOC_DMA_LOW && (intptr_t)p < SOC_DMA_HIGH;
}
inline static bool IRAM_ATTR esp_ptr_word_aligned(const void *p)
{
return ((intptr_t)p) % 4 == 0;
}
inline static bool IRAM_ATTR esp_ptr_executable(const void *p)
{
intptr_t ip = (intptr_t) p;

30
docs/en/api-reference/peripherals/spi_slave.rst
View file

@ -7,7 +7,7 @@ Overview
The ESP32 has four SPI peripheral devices, called SPI0, SPI1, HSPI and VSPI. SPI0 is entirely dedicated to
the flash cache the ESP32 uses to map the SPI flash device it is connected to into memory. SPI1 is
connected to the same hardware lines as SPI0 and is used to write to the flash chip. HSPI and VSPI
are free to use, and with the spi_slave driver, these can be used as a SPI slave, driven from a
are free to use, and with the spi_slave driver, these can be used as a SPI slave, driven from a
connected SPI master.
The spi_slave driver
@ -21,9 +21,9 @@ Terminology
The spi_slave driver uses the following terms:
* Host: The SPI peripheral inside the ESP32 initiating the SPI transmissions. One of HSPI or VSPI.
* Host: The SPI peripheral inside the ESP32 initiating the SPI transmissions. One of HSPI or VSPI.
* Bus: The SPI bus, common to all SPI devices connected to a master. In general the bus consists of the
miso, mosi, sclk and optionally quadwp and quadhd signals. The SPI slaves are connected to these
miso, mosi, sclk and optionally quadwp and quadhd signals. The SPI slaves are connected to these
signals in parallel. Each SPI slave is also connected to one CS signal.
- miso - Also known as q, this is the output of the serial stream from the ESP32 to the SPI master
@ -50,15 +50,15 @@ the master makes CS high again.
Using the spi_slave driver
^^^^^^^^^^^^^^^^^^^^^^^^^^^
- Initialize a SPI peripheral as a slave by calling ``spi_slave_initialize``. Make sure to set the
- Initialize a SPI peripheral as a slave by calling ``spi_slave_initialize``. Make sure to set the
correct IO pins in the ``bus_config`` struct. Take care to set signals that are not needed to -1.
A DMA channel (either 1 or 2) must be given if transactions will be larger than 32 bytes, if not
the dma_chan parameter may be 0.
- To set up a transaction, fill one or more spi_transaction_t structure with any transaction
- To set up a transaction, fill one or more spi_transaction_t structure with any transaction
parameters you need. Either queue all transactions by calling ``spi_slave_queue_trans``, later
quering the result using ``spi_slave_get_trans_result``, or handle all requests synchroneously
by feeding them into ``spi_slave_transmit``. The latter two functions will block until the
by feeding them into ``spi_slave_transmit``. The latter two functions will block until the
master has initiated and finished a transaction, causing the queued data to be sent and received.
- Optional: to unload the SPI slave driver, call ``spi_slave_free``.
@ -69,7 +69,7 @@ Transaction data and master/slave length mismatches
Normally, data to be transferred to or from a device will be read from or written to a chunk of memory
indicated by the ``rx_buffer`` and ``tx_buffer`` members of the transaction structure. The SPI driver
may decide to use DMA for transfers, so these buffers should be allocated in DMA-capable memory using
may decide to use DMA for transfers, so these buffers should be allocated in DMA-capable memory using
``pvPortMallocCaps(size, MALLOC_CAP_DMA)``.
The amount of data written to the buffers is limited by the ``length`` member of the transaction structure:
@ -78,13 +78,23 @@ length of the SPI transaction; this is determined by the master as it drives the
transferred can be read from the ``trans_len`` member of the ``spi_slave_transaction_t`` structure after transaction.
In case the length of the transmission is larger than the buffer length, only the start of the transmission
will be sent and received, and the ``trans_len`` is set to ``length`` instead of the actual length. It's recommended to
set ``length`` longer than the maximum length expected if the ``trans_len`` is required. In case the transmission
set ``length`` longer than the maximum length expected if the ``trans_len`` is required. In case the transmission
length is shorter than the buffer length, only data up to the length of the buffer will be exchanged.
Warning: Due to a design peculiarity in the ESP32, if the amount of bytes sent by the master or the length
of the transmission queues in the slave driver, in bytes, is not both larger than eight and dividable by
Warning: Due to a design peculiarity in the ESP32, if the amount of bytes sent by the master or the length
of the transmission queues in the slave driver, in bytes, is not both larger than eight and dividable by
four, the SPI hardware can fail to write the last one to seven bytes to the receive buffer.
Restrictions and Known issues
-------------------------------
1. If the DMA is enabled, the rx buffer should be WORD aligned, i.e. Start
from the boundary of 32-bit and have length of multiples of 4 bytes. Or the
DMA may write incorrectly or out of the boundary.The driver will check for
this.
Also, master should write lengths which are a multiple of 4 bytes. Data
longer than that will be discarded.
Application Example
-------------------