On 12/02/2025 14:46, Vishwaroop A wrote:
Previous generations of Tegra supported DMA operations by an external
DMA controller, but the QSPI on Tegra234 devices now have an internal
DMA controller.
Internal DMA: Uses the QSPI controller's built-in DMA engine, which is
limited in capabilities and tied directly to the QSPI module.
External DMA: Utilizes a separate, GPCDMA DMA controller that can
transfer data between QSPI and any memory location.
Native DMA Initialization: Introduce routines to initialize and
configure native DMA channels for both transmit and receive paths.
Set up DMA mapping functions to manage buffer addresses effectively.
Enhance Transfer Logic: Implement logic to choose between CPU-based
and DMA-based transfers based on data size.
Signed-off-by: Vishwaroop A <va@xxxxxxxxxx>
---
drivers/spi/spi-tegra210-quad.c | 218 ++++++++++++++++++--------------
1 file changed, 126 insertions(+), 92 deletions(-)
diff --git a/drivers/spi/spi-tegra210-quad.c b/drivers/spi/spi-tegra210-quad.c
index 04f41e92c1e2..7463b00b1ffb 100644
--- a/drivers/spi/spi-tegra210-quad.c
+++ b/drivers/spi/spi-tegra210-quad.c
@@ -111,6 +111,9 @@
#define QSPI_DMA_BLK 0x024
#define QSPI_DMA_BLK_SET(x) (((x) & 0xffff) << 0)
+#define QSPI_DMA_MEM_ADDRESS_REG 0x028
+#define QSPI_DMA_HI_ADDRESS_REG 0x02c
+
#define QSPI_TX_FIFO 0x108
#define QSPI_RX_FIFO 0x188
@@ -167,9 +170,9 @@ enum tegra_qspi_transfer_type {
};
struct tegra_qspi_soc_data {
- bool has_dma;
bool cmb_xfer_capable;
bool supports_tpm;
+ bool has_ext_dma;
unsigned int cs_count;
};
@@ -605,17 +608,21 @@ static void tegra_qspi_dma_unmap_xfer(struct tegra_qspi *tqspi, struct spi_trans
len = DIV_ROUND_UP(tqspi->curr_dma_words * tqspi->bytes_per_word, 4) * 4;
- dma_unmap_single(tqspi->dev, t->tx_dma, len, DMA_TO_DEVICE);
- dma_unmap_single(tqspi->dev, t->rx_dma, len, DMA_FROM_DEVICE);
+ if (t->tx_buf)
+ dma_unmap_single(tqspi->dev, t->tx_dma, len, DMA_TO_DEVICE);
+ if (t->rx_buf)
+ dma_unmap_single(tqspi->dev, t->rx_dma, len, DMA_FROM_DEVICE);
}
static int tegra_qspi_start_dma_based_transfer(struct tegra_qspi *tqspi, struct spi_transfer *t)
{
struct dma_slave_config dma_sconfig = { 0 };
+ dma_addr_t rx_dma_phys, tx_dma_phys;
unsigned int len;
u8 dma_burst;
int ret = 0;
u32 val;
+ bool has_ext_dma = tqspi->soc_data->has_ext_dma;
if (tqspi->is_packed) {
ret = tegra_qspi_dma_map_xfer(tqspi, t);
@@ -634,60 +641,85 @@ static int tegra_qspi_start_dma_based_transfer(struct tegra_qspi *tqspi, struct
len = tqspi->curr_dma_words * 4;
/* set attention level based on length of transfer */
- val = 0;
- if (len & 0xf) {
- val |= QSPI_TX_TRIG_1 | QSPI_RX_TRIG_1;
- dma_burst = 1;
- } else if (((len) >> 4) & 0x1) {
- val |= QSPI_TX_TRIG_4 | QSPI_RX_TRIG_4;
- dma_burst = 4;
- } else {
- val |= QSPI_TX_TRIG_8 | QSPI_RX_TRIG_8;
- dma_burst = 8;
+ if (has_ext_dma) {
+ val = 0;
+ if (len & 0xf) {
+ val |= QSPI_TX_TRIG_1 | QSPI_RX_TRIG_1;
+ dma_burst = 1;
+ } else if (((len) >> 4) & 0x1) {
+ val |= QSPI_TX_TRIG_4 | QSPI_RX_TRIG_4;
+ dma_burst = 4;
+ } else {
+ val |= QSPI_TX_TRIG_8 | QSPI_RX_TRIG_8;
+ dma_burst = 8;
+ }
+
+ tegra_qspi_writel(tqspi, val, QSPI_DMA_CTL);
}
- tegra_qspi_writel(tqspi, val, QSPI_DMA_CTL);
tqspi->dma_control_reg = val;
dma_sconfig.device_fc = true;
- if (tqspi->cur_direction & DATA_DIR_TX) {
- dma_sconfig.dst_addr = tqspi->phys + QSPI_TX_FIFO;
- dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
- dma_sconfig.dst_maxburst = dma_burst;
- ret = dmaengine_slave_config(tqspi->tx_dma_chan, &dma_sconfig);
- if (ret < 0) {
- dev_err(tqspi->dev, "failed DMA slave config: %d\n", ret);
- return ret;
- }
- tegra_qspi_copy_client_txbuf_to_qspi_txbuf(tqspi, t);
- ret = tegra_qspi_start_tx_dma(tqspi, t, len);
- if (ret < 0) {
- dev_err(tqspi->dev, "failed to starting TX DMA: %d\n", ret);
- return ret;
+ if ((tqspi->cur_direction & DATA_DIR_TX)) {
+ if (has_ext_dma) {
For consistency with 'handle_dma_based_xfer' I think it is better to
use 'tqspi->tx_dma_chan' here.
+ dma_sconfig.dst_addr = tqspi->phys + QSPI_TX_FIFO;
+ dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ dma_sconfig.dst_maxburst = dma_burst;
+ ret = dmaengine_slave_config(tqspi->tx_dma_chan, &dma_sconfig);
+ if (ret < 0) {
+ dev_err(tqspi->dev, "failed DMA slave config: %d\n", ret);
+ return ret;
+ }
+
+ tegra_qspi_copy_client_txbuf_to_qspi_txbuf(tqspi, t);
+ ret = tegra_qspi_start_tx_dma(tqspi, t, len);
+ if (ret < 0) {
+ dev_err(tqspi->dev, "failed to starting TX DMA: %d\n", ret);
+ return ret;
+ }
+ } else {
+ if (tqspi->is_packed)
+ tx_dma_phys = t->tx_dma;
+ else
+ tx_dma_phys = tqspi->tx_dma_phys;
+ tegra_qspi_copy_client_txbuf_to_qspi_txbuf(tqspi, t);
+ tegra_qspi_writel(tqspi, lower_32_bits(tx_dma_phys),
+ QSPI_DMA_MEM_ADDRESS_REG);
+ tegra_qspi_writel(tqspi, (upper_32_bits(tx_dma_phys) & 0xff),
+ QSPI_DMA_HI_ADDRESS_REG);
}
}
if (tqspi->cur_direction & DATA_DIR_RX) {
- dma_sconfig.src_addr = tqspi->phys + QSPI_RX_FIFO;
- dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
- dma_sconfig.src_maxburst = dma_burst;
- ret = dmaengine_slave_config(tqspi->rx_dma_chan, &dma_sconfig);
- if (ret < 0) {
- dev_err(tqspi->dev, "failed DMA slave config: %d\n", ret);
- return ret;
- }
-
- dma_sync_single_for_device(tqspi->dev, tqspi->rx_dma_phys,
- tqspi->dma_buf_size,
- DMA_FROM_DEVICE);
-
- ret = tegra_qspi_start_rx_dma(tqspi, t, len);
- if (ret < 0) {
- dev_err(tqspi->dev, "failed to start RX DMA: %d\n", ret);
- if (tqspi->cur_direction & DATA_DIR_TX)
- dmaengine_terminate_all(tqspi->tx_dma_chan);
- return ret;
+ if (has_ext_dma) {
Same here.
+ dma_sconfig.src_addr = tqspi->phys + QSPI_RX_FIFO;
+ dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ dma_sconfig.src_maxburst = dma_burst;
+ ret = dmaengine_slave_config(tqspi->rx_dma_chan, &dma_sconfig);
+ if (ret < 0) {
+ dev_err(tqspi->dev, "failed DMA slave config: %d\n", ret);
+ return ret;
+ }
+ dma_sync_single_for_device(tqspi->dev, tqspi->rx_dma_phys,
+ tqspi->dma_buf_size, DMA_FROM_DEVICE);
+ ret = tegra_qspi_start_rx_dma(tqspi, t, len);
+ if (ret < 0) {
+ dev_err(tqspi->dev, "failed to start RX DMA: %d\n", ret);
+ if (tqspi->cur_direction & DATA_DIR_TX)
+ dmaengine_terminate_all(tqspi->tx_dma_chan);
+ return ret;
+ }
+ } else {
+ if (tqspi->is_packed)
+ rx_dma_phys = t->rx_dma;
+ else
+ rx_dma_phys = tqspi->rx_dma_phys;
+
+ tegra_qspi_writel(tqspi, lower_32_bits(rx_dma_phys),
+ QSPI_DMA_MEM_ADDRESS_REG);
+ tegra_qspi_writel(tqspi, (upper_32_bits(rx_dma_phys) & 0xff),
+ QSPI_DMA_HI_ADDRESS_REG);
}
}
@@ -726,9 +758,6 @@ static int tegra_qspi_start_cpu_based_transfer(struct tegra_qspi *qspi, struct s
static void tegra_qspi_deinit_dma(struct tegra_qspi *tqspi)
{
- if (!tqspi->soc_data->has_dma)
- return;
-
if (tqspi->tx_dma_buf) {
dma_free_coherent(tqspi->dev, tqspi->dma_buf_size,
tqspi->tx_dma_buf, tqspi->tx_dma_phys);
@@ -759,16 +788,26 @@ static int tegra_qspi_init_dma(struct tegra_qspi *tqspi)
u32 *dma_buf;
int err;
- if (!tqspi->soc_data->has_dma)
- return 0;
+ if (tqspi->soc_data->has_ext_dma) {
+ dma_chan = dma_request_chan(tqspi->dev, "rx");
+ if (IS_ERR(dma_chan)) {
+ err = PTR_ERR(dma_chan);
+ goto err_out;
+ }
- dma_chan = dma_request_chan(tqspi->dev, "rx");
- if (IS_ERR(dma_chan)) {
- err = PTR_ERR(dma_chan);
- goto err_out;
- }
+ tqspi->rx_dma_chan = dma_chan;
- tqspi->rx_dma_chan = dma_chan;
+ dma_chan = dma_request_chan(tqspi->dev, "tx");
+ if (IS_ERR(dma_chan)) {
+ err = PTR_ERR(dma_chan);
+ goto err_out;
+ }
+
+ tqspi->tx_dma_chan = dma_chan;
+ } else {
+ tqspi->rx_dma_chan = NULL;
+ tqspi->tx_dma_chan = NULL;
+ }
dma_buf = dma_alloc_coherent(tqspi->dev, tqspi->dma_buf_size, &dma_phys, GFP_KERNEL);
if (!dma_buf) {
@@ -779,14 +818,6 @@ static int tegra_qspi_init_dma(struct tegra_qspi *tqspi)
tqspi->rx_dma_buf = dma_buf;
tqspi->rx_dma_phys = dma_phys;
- dma_chan = dma_request_chan(tqspi->dev, "tx");
- if (IS_ERR(dma_chan)) {
- err = PTR_ERR(dma_chan);
- goto err_out;
- }
-
- tqspi->tx_dma_chan = dma_chan;
-
dma_buf = dma_alloc_coherent(tqspi->dev, tqspi->dma_buf_size, &dma_phys, GFP_KERNEL);
if (!dma_buf) {
err = -ENOMEM;
@@ -1056,6 +1087,7 @@ static int tegra_qspi_combined_seq_xfer(struct tegra_qspi *tqspi,
struct spi_message *msg)
{
bool is_first_msg = true;
+ bool has_ext_dma = tqspi->soc_data->has_ext_dma;
struct spi_transfer *xfer;
struct spi_device *spi = msg->spi;
u8 transfer_phase = 0;
@@ -1128,15 +1160,12 @@ static int tegra_qspi_combined_seq_xfer(struct tegra_qspi *tqspi,
if (WARN_ON(ret == 0)) {
dev_err(tqspi->dev, "QSPI Transfer failed with timeout: %d\n",
ret);
- if (tqspi->is_curr_dma_xfer &&
- (tqspi->cur_direction & DATA_DIR_TX))
- dmaengine_terminate_all
- (tqspi->tx_dma_chan);
-
- if (tqspi->is_curr_dma_xfer &&
- (tqspi->cur_direction & DATA_DIR_RX))
- dmaengine_terminate_all
- (tqspi->rx_dma_chan);
+ if (tqspi->is_curr_dma_xfer && has_ext_dma) {
+ if (tqspi->cur_direction & DATA_DIR_TX)
+ dmaengine_terminate_all(tqspi->tx_dma_chan);
+ if (tqspi->cur_direction & DATA_DIR_RX)
+ dmaengine_terminate_all(tqspi->rx_dma_chan);
+ }
/* Abort transfer by resetting pio/dma bit */
if (!tqspi->is_curr_dma_xfer) {
@@ -1197,6 +1226,7 @@ static int tegra_qspi_non_combined_seq_xfer(struct tegra_qspi *tqspi,
struct spi_device *spi = msg->spi;
struct spi_transfer *transfer;
bool is_first_msg = true;
+ bool has_ext_dma = tqspi->soc_data->has_ext_dma;
int ret = 0, val = 0;
msg->status = 0;
@@ -1251,10 +1281,12 @@ static int tegra_qspi_non_combined_seq_xfer(struct tegra_qspi *tqspi,
QSPI_DMA_TIMEOUT);
if (WARN_ON(ret == 0)) {
dev_err(tqspi->dev, "transfer timeout\n");
- if (tqspi->is_curr_dma_xfer && (tqspi->cur_direction & DATA_DIR_TX))
- dmaengine_terminate_all(tqspi->tx_dma_chan);
- if (tqspi->is_curr_dma_xfer && (tqspi->cur_direction & DATA_DIR_RX))
- dmaengine_terminate_all(tqspi->rx_dma_chan);
+ if (tqspi->is_curr_dma_xfer && has_ext_dma) {
And here.
+ if (tqspi->cur_direction & DATA_DIR_TX)
+ dmaengine_terminate_all(tqspi->tx_dma_chan);
+ if (tqspi->cur_direction & DATA_DIR_RX)
+ dmaengine_terminate_all(tqspi->rx_dma_chan);
+ }
tegra_qspi_handle_error(tqspi);
ret = -EIO;
goto complete_xfer;
@@ -1323,7 +1355,7 @@ static bool tegra_qspi_validate_cmb_seq(struct tegra_qspi *tqspi,
return false;
xfer = list_next_entry(xfer, transfer_list);
}
- if (!tqspi->soc_data->has_dma && xfer->len > (QSPI_FIFO_DEPTH << 2))
+ if (!tqspi->soc_data->has_ext_dma && xfer->len > (QSPI_FIFO_DEPTH << 2))
return false;
return true;
@@ -1388,30 +1420,32 @@ static irqreturn_t handle_dma_based_xfer(struct tegra_qspi *tqspi)
if (tqspi->cur_direction & DATA_DIR_TX) {
if (tqspi->tx_status) {
- dmaengine_terminate_all(tqspi->tx_dma_chan);
- err += 1;
- } else {
+ if (tqspi->tx_dma_chan)
+ dmaengine_terminate_all(tqspi->tx_dma_chan);
+ err++;
+ } else if (tqspi->tx_dma_chan) {
wait_status = wait_for_completion_interruptible_timeout(
&tqspi->tx_dma_complete, QSPI_DMA_TIMEOUT);
if (wait_status <= 0) {
dmaengine_terminate_all(tqspi->tx_dma_chan);
dev_err(tqspi->dev, "failed TX DMA transfer\n");
- err += 1;
+ err++;
}
}
}
if (tqspi->cur_direction & DATA_DIR_RX) {
if (tqspi->rx_status) {
- dmaengine_terminate_all(tqspi->rx_dma_chan);
- err += 2;
- } else {
+ if (tqspi->rx_dma_chan)
+ dmaengine_terminate_all(tqspi->rx_dma_chan);
+ err++;
+ } else if (tqspi->rx_dma_chan) {
wait_status = wait_for_completion_interruptible_timeout(
&tqspi->rx_dma_complete, QSPI_DMA_TIMEOUT);
if (wait_status <= 0) {
dmaengine_terminate_all(tqspi->rx_dma_chan);
dev_err(tqspi->dev, "failed RX DMA transfer\n");
- err += 2;
+ err++;
}
}
}
@@ -1474,28 +1508,28 @@ static irqreturn_t tegra_qspi_isr_thread(int irq, void *context_data)
}
static struct tegra_qspi_soc_data tegra210_qspi_soc_data = {
- .has_dma = true,
+ .has_ext_dma = true,
.cmb_xfer_capable = false,
.supports_tpm = false,
.cs_count = 1,
};
static struct tegra_qspi_soc_data tegra186_qspi_soc_data = {
- .has_dma = true,
+ .has_ext_dma = true,
.cmb_xfer_capable = true,
.supports_tpm = false,
.cs_count = 1,
};
static struct tegra_qspi_soc_data tegra234_qspi_soc_data = {
- .has_dma = false,
+ .has_ext_dma = false,
.cmb_xfer_capable = true,
.supports_tpm = true,
.cs_count = 1,
};
static struct tegra_qspi_soc_data tegra241_qspi_soc_data = {
- .has_dma = false,
+ .has_ext_dma = true,
.cmb_xfer_capable = true,
.supports_tpm = true,
.cs_count = 4,
--
nvpublic
