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Subject[PATCH v3 2/3] spi: tegra210-quad: combined sequence mode
Date
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 <kyarlagadda@nvidia.com>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
---
drivers/spi/spi-tegra210-quad.c | 238 +++++++++++++++++++++++++++++++-
1 file changed, 233 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/spi-tegra210-quad.c b/drivers/spi/spi-tegra210-quad.c
index 517a348d1c19..66f647f32876 100644
--- a/drivers/spi/spi-tegra210-quad.c
+++ b/drivers/spi/spi-tegra210-quad.c
@@ -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 {
@@ -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 */
@@ -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;
@@ -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)) {
@@ -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;
}

@@ -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[] = {
@@ -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))
--
2.17.1
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