spi: Using Trigger number to transmit/receive data

In order to transmit and receive data when have 32 bytes of data that
ready has prepared on Transmit/Receive Buffer to transmit or receive.
Instead transmits/receives a byte data using Transmit/Receive Buffer
Data Triggering Number will improve the speed of transfer data.

Signed-off-by: Hiep Cao Minh <cm-hiep@jinso.co.jp>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 46ce47076e63d143f10b298f386877bb960b8f56..fd276f990d4dba33dfb9a1e6918934ccd954b739 100644 (file)
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -177,6 +177,13 @@
 #define SPBFCR_RXRST           0x40    /* Receive Buffer Data Reset */
 #define SPBFCR_TXTRG_MASK      0x30    /* Transmit Buffer Data Triggering Number */
 #define SPBFCR_RXTRG_MASK      0x07    /* Receive Buffer Data Triggering Number */
+/* QSPI on R-Car Gen2 */
+#define SPBFCR_TXTRG_1B                0x00    /* 31 bytes (1 byte available) */
+#define SPBFCR_TXTRG_32B       0x30    /* 0 byte (32 bytes available) */
+#define SPBFCR_RXTRG_1B                0x00    /* 1 byte (31 bytes available) */
+#define SPBFCR_RXTRG_32B       0x07    /* 32 bytes (0 byte available) */
+
+#define QSPI_BUFFER_SIZE        32u
 
 struct rspi_data {
        void __iomem *addr;
@@ -366,6 +373,52 @@ static int qspi_set_config_register(struct rspi_data *rspi, int access_size)
        return 0;
 }
 
+static void qspi_update(const struct rspi_data *rspi, u8 mask, u8 val, u8 reg)
+{
+       u8 data;
+
+       data = rspi_read8(rspi, reg);
+       data &= ~mask;
+       data |= (val & mask);
+       rspi_write8(rspi, data, reg);
+}
+
+static int qspi_set_send_trigger(struct rspi_data *rspi, unsigned int len)
+{
+       unsigned int n;
+
+       n = min(len, QSPI_BUFFER_SIZE);
+
+       if (len >= QSPI_BUFFER_SIZE) {
+               /* sets triggering number to 32 bytes */
+               qspi_update(rspi, SPBFCR_TXTRG_MASK,
+                            SPBFCR_TXTRG_32B, QSPI_SPBFCR);
+       } else {
+               /* sets triggering number to 1 byte */
+               qspi_update(rspi, SPBFCR_TXTRG_MASK,
+                            SPBFCR_TXTRG_1B, QSPI_SPBFCR);
+       }
+
+       return n;
+}
+
+static void qspi_set_receive_trigger(struct rspi_data *rspi, unsigned int len)
+{
+       unsigned int n;
+
+       n = min(len, QSPI_BUFFER_SIZE);
+
+       if (len >= QSPI_BUFFER_SIZE) {
+               /* sets triggering number to 32 bytes */
+               qspi_update(rspi, SPBFCR_RXTRG_MASK,
+                            SPBFCR_RXTRG_32B, QSPI_SPBFCR);
+       } else {
+               /* sets triggering number to 1 byte */
+               qspi_update(rspi, SPBFCR_RXTRG_MASK,
+                            SPBFCR_RXTRG_1B, QSPI_SPBFCR);
+       }
+}
+
 #define set_config_register(spi, n) spi->ops->set_config_register(spi, n)
 
 static void rspi_enable_irq(const struct rspi_data *rspi, u8 enable)
@@ -609,19 +662,29 @@ static bool rspi_can_dma(struct spi_master *master, struct spi_device *spi,
        return __rspi_can_dma(rspi, xfer);
 }
 
-static int rspi_common_transfer(struct rspi_data *rspi,
-                               struct spi_transfer *xfer)
+static int rspi_dma_check_then_transfer(struct rspi_data *rspi,
+                                        struct spi_transfer *xfer)
 {
-       int ret;
-
        if (rspi->master->can_dma && __rspi_can_dma(rspi, xfer)) {
                /* rx_buf can be NULL on RSPI on SH in TX-only Mode */
-               ret = rspi_dma_transfer(rspi, &xfer->tx_sg,
+               int ret = rspi_dma_transfer(rspi, &xfer->tx_sg,
                                        xfer->rx_buf ? &xfer->rx_sg : NULL);
                if (ret != -EAGAIN)
-                       return ret;
+                       return 0;
        }
 
+       return -EAGAIN;
+}
+
+static int rspi_common_transfer(struct rspi_data *rspi,
+                               struct spi_transfer *xfer)
+{
+       int ret;
+
+       ret = rspi_dma_check_then_transfer(rspi, xfer);
+       if (ret != -EAGAIN)
+               return ret;
+
        ret = rspi_pio_transfer(rspi, xfer->tx_buf, xfer->rx_buf, xfer->len);
        if (ret < 0)
                return ret;
@@ -661,12 +724,59 @@ static int rspi_rz_transfer_one(struct spi_master *master,
        return rspi_common_transfer(rspi, xfer);
 }
 
+static int qspi_trigger_transfer_out_int(struct rspi_data *rspi, const u8 *tx,
+                                       u8 *rx, unsigned int len)
+{
+       unsigned int i, n, ret;
+       int error;
+
+       while (len > 0) {
+               n = qspi_set_send_trigger(rspi, len);
+               qspi_set_receive_trigger(rspi, len);
+               if (n == QSPI_BUFFER_SIZE) {
+                       error = rspi_wait_for_tx_empty(rspi);
+                       if (error < 0) {
+                               dev_err(&rspi->master->dev, "transmit timeout\n");
+                               return error;
+                       }
+                       for (i = 0; i < n; i++)
+                               rspi_write_data(rspi, *tx++);
+
+                       error = rspi_wait_for_rx_full(rspi);
+                       if (error < 0) {
+                               dev_err(&rspi->master->dev, "receive timeout\n");
+                               return error;
+                       }
+                       for (i = 0; i < n; i++)
+                               *rx++ = rspi_read_data(rspi);
+               } else {
+                       ret = rspi_pio_transfer(rspi, tx, rx, n);
+                       if (ret < 0)
+                               return ret;
+               }
+               len -= n;
+       }
+
+       return 0;
+}
+
 static int qspi_transfer_out_in(struct rspi_data *rspi,
                                struct spi_transfer *xfer)
 {
+       int ret;
+
        qspi_receive_init(rspi);
 
-       return rspi_common_transfer(rspi, xfer);
+       ret = rspi_dma_check_then_transfer(rspi, xfer);
+       if (ret != -EAGAIN)
+               return ret;
+
+       ret = qspi_trigger_transfer_out_int(rspi, xfer->tx_buf,
+                                           xfer->rx_buf, xfer->len);
+       if (ret < 0)
+               return ret;
+
+       return 0;
 }
 
 static int qspi_transfer_out(struct rspi_data *rspi, struct spi_transfer *xfer)