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spi: tegra210-quad: combined sequence mode
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Add combined sequence mode supported by Tegra QSPI controller.
For commands which contain cmd, addr, data parts to it, controller
can accept all 3 transfers at once and avoid interrupt for each
transfer. This would improve read & write performance.

Signed-off-by: Krishna Yarlagadda <[email protected]>
Reported-by: kernel test robot <[email protected]>
Reported-by: Dan Carpenter <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>
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@kkyarlagadda @broonie
kkyarlagadda authored and broonie committed Mar 8, 2022
1 parent 75a1b44 commit 1b8342c
Showing 1 changed file with 233 additions and 5 deletions.
238 changes: 233 additions & 5 deletions drivers/spi/spi-tegra210-quad.c
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Original file line number Diff line number Diff line change
Expand Up @@ -121,14 +121,39 @@
#define QSPI_NUM_DUMMY_CYCLE(x) (((x) & 0xff) << 0)
#define QSPI_DUMMY_CYCLES_MAX 0xff

#define QSPI_CMB_SEQ_CMD 0x19c
#define QSPI_COMMAND_VALUE_SET(X) (((x) & 0xFF) << 0)

#define QSPI_CMB_SEQ_CMD_CFG 0x1a0
#define QSPI_COMMAND_X1_X2_X4(x) (((x) & 0x3) << 13)
#define QSPI_COMMAND_X1_X2_X4_MASK (0x03 << 13)
#define QSPI_COMMAND_SDR_DDR BIT(12)
#define QSPI_COMMAND_SIZE_SET(x) (((x) & 0xFF) << 0)

#define QSPI_GLOBAL_CONFIG 0X1a4
#define QSPI_CMB_SEQ_EN BIT(0)

#define QSPI_CMB_SEQ_ADDR 0x1a8
#define QSPI_ADDRESS_VALUE_SET(X) (((x) & 0xFFFF) << 0)

#define QSPI_CMB_SEQ_ADDR_CFG 0x1ac
#define QSPI_ADDRESS_X1_X2_X4(x) (((x) & 0x3) << 13)
#define QSPI_ADDRESS_X1_X2_X4_MASK (0x03 << 13)
#define QSPI_ADDRESS_SDR_DDR BIT(12)
#define QSPI_ADDRESS_SIZE_SET(x) (((x) & 0xFF) << 0)

#define DATA_DIR_TX BIT(0)
#define DATA_DIR_RX BIT(1)

#define QSPI_DMA_TIMEOUT (msecs_to_jiffies(1000))
#define DEFAULT_QSPI_DMA_BUF_LEN (64 * 1024)
#define CMD_TRANSFER 0
#define ADDR_TRANSFER 1
#define DATA_TRANSFER 2

struct tegra_qspi_soc_data {
bool has_dma;
bool cmb_xfer_capable;
};

struct tegra_qspi_client_data {
Expand Down Expand Up @@ -912,7 +937,6 @@ static int tegra_qspi_setup(struct spi_device *spi)
cdata = tegra_qspi_parse_cdata_dt(spi);
spi->controller_data = cdata;
}

spin_lock_irqsave(&tqspi->lock, flags);

/* keep default cs state to inactive */
Expand Down Expand Up @@ -971,19 +995,179 @@ static void tegra_qspi_transfer_end(struct spi_device *spi)
tegra_qspi_writel(tqspi, tqspi->def_command1_reg, QSPI_COMMAND1);
}

static int tegra_qspi_transfer_one_message(struct spi_master *master, struct spi_message *msg)
static u32 tegra_qspi_cmd_config(bool is_ddr, u8 bus_width, u8 len)
{
u32 cmd_config = 0;

/* Extract Command configuration and value */
if (is_ddr)
cmd_config |= QSPI_COMMAND_SDR_DDR;
else
cmd_config &= ~QSPI_COMMAND_SDR_DDR;

cmd_config |= QSPI_COMMAND_X1_X2_X4(bus_width);
cmd_config |= QSPI_COMMAND_SIZE_SET((len * 8) - 1);

return cmd_config;
}

static u32 tegra_qspi_addr_config(bool is_ddr, u8 bus_width, u8 len)
{
u32 addr_config = 0;

/* Extract Address configuration and value */
is_ddr = 0; //Only SDR mode supported
bus_width = 0; //X1 mode

if (is_ddr)
addr_config |= QSPI_ADDRESS_SDR_DDR;
else
addr_config &= ~QSPI_ADDRESS_SDR_DDR;

addr_config |= QSPI_ADDRESS_X1_X2_X4(bus_width);
addr_config |= QSPI_ADDRESS_SIZE_SET((len * 8) - 1);

return addr_config;
}

static int tegra_qspi_combined_seq_xfer(struct tegra_qspi *tqspi,
struct spi_message *msg)
{
bool is_first_msg = true;
struct spi_transfer *xfer;
struct spi_device *spi = msg->spi;
u8 transfer_phase = 0;
u32 cmd1 = 0, dma_ctl = 0;
int ret = 0;
u32 address_value = 0;
u32 cmd_config = 0, addr_config = 0;
u8 cmd_value = 0, val = 0;

/* Enable Combined sequence mode */
val = tegra_qspi_readl(tqspi, QSPI_GLOBAL_CONFIG);
val |= QSPI_CMB_SEQ_EN;
tegra_qspi_writel(tqspi, val, QSPI_GLOBAL_CONFIG);
/* Process individual transfer list */
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
switch (transfer_phase) {
case CMD_TRANSFER:
/* X1 SDR mode */
cmd_config = tegra_qspi_cmd_config(false, 0,
xfer->len);
cmd_value = *((const u8 *)(xfer->tx_buf));
break;
case ADDR_TRANSFER:
/* X1 SDR mode */
addr_config = tegra_qspi_addr_config(false, 0,
xfer->len);
address_value = *((const u32 *)(xfer->tx_buf));
break;
case DATA_TRANSFER:
/* Program Command, Address value in register */
tegra_qspi_writel(tqspi, cmd_value, QSPI_CMB_SEQ_CMD);
tegra_qspi_writel(tqspi, address_value,
QSPI_CMB_SEQ_ADDR);
/* Program Command and Address config in register */
tegra_qspi_writel(tqspi, cmd_config,
QSPI_CMB_SEQ_CMD_CFG);
tegra_qspi_writel(tqspi, addr_config,
QSPI_CMB_SEQ_ADDR_CFG);

reinit_completion(&tqspi->xfer_completion);
cmd1 = tegra_qspi_setup_transfer_one(spi, xfer,
is_first_msg);
ret = tegra_qspi_start_transfer_one(spi, xfer,
cmd1);

if (ret < 0) {
dev_err(tqspi->dev, "Failed to start transfer-one: %d\n",
ret);
return ret;
}

is_first_msg = false;
ret = wait_for_completion_timeout
(&tqspi->xfer_completion,
QSPI_DMA_TIMEOUT);

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);

/* Abort transfer by resetting pio/dma bit */
if (!tqspi->is_curr_dma_xfer) {
cmd1 = tegra_qspi_readl
(tqspi,
QSPI_COMMAND1);
cmd1 &= ~QSPI_PIO;
tegra_qspi_writel
(tqspi, cmd1,
QSPI_COMMAND1);
} else {
dma_ctl = tegra_qspi_readl
(tqspi,
QSPI_DMA_CTL);
dma_ctl &= ~QSPI_DMA_EN;
tegra_qspi_writel(tqspi, dma_ctl,
QSPI_DMA_CTL);
}

/* Reset controller if timeout happens */
if (device_reset(tqspi->dev) < 0)
dev_warn_once(tqspi->dev,
"device reset failed\n");
ret = -EIO;
goto exit;
}

if (tqspi->tx_status || tqspi->rx_status) {
dev_err(tqspi->dev, "QSPI Transfer failed\n");
tqspi->tx_status = 0;
tqspi->rx_status = 0;
ret = -EIO;
goto exit;
}
break;
default:
ret = -EINVAL;
goto exit;
}
msg->actual_length += xfer->len;
transfer_phase++;
}

exit:
msg->status = ret;

return ret;
}

static int tegra_qspi_non_combined_seq_xfer(struct tegra_qspi *tqspi,
struct spi_message *msg)
{
struct tegra_qspi *tqspi = spi_master_get_devdata(master);
struct spi_device *spi = msg->spi;
struct spi_transfer *transfer;
bool is_first_msg = true;
int ret;
int ret = 0, val = 0;

msg->status = 0;
msg->actual_length = 0;
tqspi->tx_status = 0;
tqspi->rx_status = 0;

/* Disable Combined sequence mode */
val = tegra_qspi_readl(tqspi, QSPI_GLOBAL_CONFIG);
val &= ~QSPI_CMB_SEQ_EN;
tegra_qspi_writel(tqspi, val, QSPI_GLOBAL_CONFIG);
list_for_each_entry(transfer, &msg->transfers, transfer_list) {
struct spi_transfer *xfer = transfer;
u8 dummy_bytes = 0;
Expand Down Expand Up @@ -1021,7 +1205,6 @@ static int tegra_qspi_transfer_one_message(struct spi_master *master, struct spi
goto complete_xfer;
}

is_first_msg = false;
ret = wait_for_completion_timeout(&tqspi->xfer_completion,
QSPI_DMA_TIMEOUT);
if (WARN_ON(ret == 0)) {
Expand Down Expand Up @@ -1066,7 +1249,48 @@ static int tegra_qspi_transfer_one_message(struct spi_master *master, struct spi
ret = 0;
exit:
msg->status = ret;

return ret;
}

static bool tegra_qspi_validate_cmb_seq(struct tegra_qspi *tqspi,
struct spi_message *msg)
{
int transfer_count = 0;
struct spi_transfer *xfer;

list_for_each_entry(xfer, &msg->transfers, transfer_list) {
transfer_count++;
}
if (!tqspi->soc_data->cmb_xfer_capable || transfer_count != 3)
return false;
xfer = list_first_entry(&msg->transfers, typeof(*xfer),
transfer_list);
if (xfer->len > 2)
return false;
xfer = list_next_entry(xfer, transfer_list);
if (xfer->len > 4 || xfer->len < 3)
return false;
xfer = list_next_entry(xfer, transfer_list);
if (!tqspi->soc_data->has_dma || xfer->len > (QSPI_FIFO_DEPTH << 2))
return false;

return true;
}

static int tegra_qspi_transfer_one_message(struct spi_master *master,
struct spi_message *msg)
{
struct tegra_qspi *tqspi = spi_master_get_devdata(master);
int ret;

if (tegra_qspi_validate_cmb_seq(tqspi, msg))
ret = tegra_qspi_combined_seq_xfer(tqspi, msg);
else
ret = tegra_qspi_non_combined_seq_xfer(tqspi, msg);

spi_finalize_current_message(master);

return ret;
}

Expand Down Expand Up @@ -1200,14 +1424,17 @@ 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,
.cmb_xfer_capable = false,
};

static struct tegra_qspi_soc_data tegra186_qspi_soc_data = {
.has_dma = true,
.cmb_xfer_capable = true,
};

static struct tegra_qspi_soc_data tegra234_qspi_soc_data = {
.has_dma = false,
.cmb_xfer_capable = true,
};

static const struct of_device_id tegra_qspi_of_match[] = {
Expand Down Expand Up @@ -1278,6 +1505,7 @@ static int tegra_qspi_probe(struct platform_device *pdev)
tqspi->dev = &pdev->dev;
spin_lock_init(&tqspi->lock);

tqspi->soc_data = device_get_match_data(&pdev->dev);
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
tqspi->base = devm_ioremap_resource(&pdev->dev, r);
if (IS_ERR(tqspi->base))
Expand Down

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