spi: rspi: Merge rspi_send_pio() and rspi_receive_pio()

rspi_send_pio() and rspi_receive_pio() are very similar:
  - the former only sends data, using TX Only Mode,
  - the latter sends and receives full duplex data to/from the hardware,
    but uses dummy transmit data.
Merge them into rspi_transfer_out_in(), now supporting full duplex if
needed.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 46 insertions, 55 deletions

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index d837c5029308..cc90136d02c8 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -389,27 +389,6 @@ static int rspi_data_out_in(struct rspi_data *rspi, u8 data)
         return rspi_data_in(rspi);
 }
 
-static int rspi_send_pio(struct rspi_data *rspi, struct spi_transfer *t)
-{
-        int remain = t->len, ret;
-        const u8 *data = t->tx_buf;
-
-        while (remain > 0) {
-                rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_TXMD,
-                            RSPI_SPCR);
-
-                ret = rspi_data_out(rspi, *data++);
-                if (ret < 0)
-                        return ret;
-                remain--;
-        }
-
-        /* Waiting for the last transmission */
-        rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE);
-
-        return 0;
-}
-
 static int qspi_send_pio(struct rspi_data *rspi, struct spi_transfer *t)
 {
         int remain = t->len, ret;
@@ -563,28 +542,6 @@ static void rspi_receive_init(const struct rspi_data *rspi)
                             RSPI_SPSR);
 }
 
-static int rspi_receive_pio(struct rspi_data *rspi, struct spi_transfer *t)
-{
-        int remain = t->len, ret;
-        u8 *data = t->rx_buf;
-
-        rspi_receive_init(rspi);
-
-        while (remain > 0) {
-                rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_TXMD,
-                            RSPI_SPCR);
-
-                /* dummy write data for generate clock */
-                ret = rspi_data_out_in(rspi, DUMMY_DATA);
-                if (ret < 0)
-                        return ret;
-                *data++ = ret;
-                remain--;
-        }
-
-        return 0;
-}
-
 static void qspi_receive_init(const struct rspi_data *rspi)
 {
         u8 spsr;
@@ -729,27 +686,61 @@ static int rspi_is_dma(const struct rspi_data *rspi, struct spi_transfer *t)
         return 0;
 }
 
+static int rspi_transfer_out_in(struct rspi_data *rspi,
+                                struct spi_transfer *xfer)
+{
+        int remain = xfer->len, ret;
+        const u8 *tx_buf = xfer->tx_buf;
+        u8 *rx_buf = xfer->rx_buf;
+        u8 spcr, data;
+
+        rspi_receive_init(rspi);
+
+        spcr = rspi_read8(rspi, RSPI_SPCR);
+        if (rx_buf)
+                spcr &= ~SPCR_TXMD;
+        else
+                spcr |= SPCR_TXMD;
+        rspi_write8(rspi, spcr, RSPI_SPCR);
+
+        while (remain > 0) {
+                data = tx_buf ? *tx_buf++ : DUMMY_DATA;
+                ret = rspi_data_out(rspi, data);
+                if (ret < 0)
+                        return ret;
+                if (rx_buf) {
+                        ret = rspi_data_in(rspi);
+                        if (ret < 0)
+                                return ret;
+                        *rx_buf++ = ret;
+                }
+                remain--;
+        }
+
+        /* Wait for the last transmission */
+        rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE);
+
+        return 0;
+}
+
 static int rspi_transfer_one(struct spi_master *master, struct spi_device *spi,
                              struct spi_transfer *xfer)
 {
         struct rspi_data *rspi = spi_master_get_devdata(master);
-        int ret = 0;
+        int ret;
+
+        if (!rspi_is_dma(rspi, xfer))
+                return rspi_transfer_out_in(rspi, xfer);
 
         if (xfer->tx_buf) {
-                if (rspi_is_dma(rspi, xfer))
-                        ret = rspi_send_dma(rspi, xfer);
-                else
-                        ret = rspi_send_pio(rspi, xfer);
+                ret = rspi_send_dma(rspi, xfer);
                 if (ret < 0)
                         return ret;
         }
-        if (xfer->rx_buf) {
-                if (rspi_is_dma(rspi, xfer))
-                        ret = rspi_receive_dma(rspi, xfer);
-                else
-                        ret = rspi_receive_pio(rspi, xfer);
-        }
-        return ret;
+        if (xfer->rx_buf)
+                return rspi_receive_dma(rspi, xfer);
+
+        return 0;
 }
 
 static int qspi_transfer_one(struct spi_master *master, struct spi_device *spi,