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bsp/atsam: Fix SPI CS change support

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The previous approach contained a severe bug which disabled the SPI
module in some cases leading to a blocked SPI bus.
This commit is contained in:
Sebastian Huber
2019-03-06 12:48:31 +01:00
parent 923a033f57
commit 847638af35
1 changed files with 12 additions and 40 deletions
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52
bsps/arm/atsam/spi/atsam_spi_bus.c
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@@ -56,9 +56,7 @@ struct atsam_spi_xdma_buf {
typedef struct {
spi_bus base;
rtems_binary_semaphore sem;
bool msg_cs_change;
const spi_ioc_transfer *msg_current;
const spi_ioc_transfer *msg_next;
uint32_t msg_todo;
int msg_error;
Spi *spi_regs;
@@ -68,7 +66,6 @@ typedef struct {
size_t leadbuf_rx_buffered_len;
size_t trailbuf_rx_buffered_len;
int transfer_in_progress;
bool chip_select_active;
bool chip_select_decode;
uint8_t spi_id;
uint32_t peripheral_clk_per_us;
@@ -320,27 +317,6 @@ static void atsam_spi_start_dma_transfer(
XDMAC_StartTransfer(pXdmac, bus->dma_tx_channel);
}
static void atsam_spi_do_transfer(
atsam_spi_bus *bus,
const spi_ioc_transfer *msg
)
{
if (!bus->chip_select_active){
Spi *spi_regs = bus->spi_regs;
bus->chip_select_active = true;
if (bus->chip_select_decode) {
spi_regs->SPI_MR = (spi_regs->SPI_MR & ~SPI_MR_PCS_Msk) | SPI_MR_PCS(msg->cs);
} else {
SPI_ChipSelect(spi_regs, 1 << msg->cs);
}
SPI_Enable(spi_regs);
}
atsam_spi_start_dma_transfer(bus, msg);
}
static int atsam_check_configure_spi(atsam_spi_bus *bus, const spi_ioc_transfer *msg)
{
if (
@@ -374,24 +350,14 @@ static void atsam_spi_setup_transfer(atsam_spi_bus *bus)
bus->transfer_in_progress = 2;
if (bus->msg_cs_change) {
bus->chip_select_active = false;
SPI_ReleaseCS(bus->spi_regs);
SPI_Disable(bus->spi_regs);
}
if (msg_todo > 0) {
const spi_ioc_transfer *msg = bus->msg_next;
const spi_ioc_transfer *msg;
int error;
bus->msg_cs_change = msg->cs_change;
bus->msg_next = msg + 1;
bus->msg_current = msg;
bus->msg_todo = msg_todo - 1;
msg = bus->msg_current;
error = atsam_check_configure_spi(bus, msg);
if (error == 0) {
atsam_spi_do_transfer(bus, msg);
atsam_spi_start_dma_transfer(bus, msg);
} else {
bus->msg_error = error;
atsam_spi_wakeup_task(bus);
@@ -424,7 +390,15 @@ static void atsam_spi_dma_callback(uint32_t channel, void *arg)
bus->spi_regs->SPI_MR = mr;
}
if (msg->cs_change) {
bus->spi_regs->SPI_CR = SPI_CR_LASTXFER;
}
atsam_spi_copy_back_rx_after_dma_transfer(bus);
bus->msg_current = msg + 1;
--bus->msg_todo;
atsam_spi_setup_transfer(bus);
}
}
@@ -437,9 +411,7 @@ static int atsam_spi_transfer(
{
atsam_spi_bus *bus = (atsam_spi_bus *)base;
bus->msg_cs_change = false;
bus->msg_next = &msgs[0];
bus->msg_current = NULL;
bus->msg_current = msgs;
bus->msg_todo = msg_count;
bus->msg_error = 0;
atsam_spi_setup_transfer(bus);