spi: rspi: Extract rspi_pio_transfer()

The various PIO loops are very similar. Consolidate into a single
function rspi_pio_transfer().

Both buffer pointers can be NULL, as RSPI supports TX-only mode, and
Dual/Quad SPI Transfers are unidirectional.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
(cherry picked from commit 6837b8e91d2a080293c30d5fe42d9692390091fa)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index ece8f60..fdbd46d 100644 (file)
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -438,15 +438,24 @@ static int rspi_data_in(struct rspi_data *rspi)
        return data;
 }
 
-static int rspi_data_out_in(struct rspi_data *rspi, u8 data)
+static int rspi_pio_transfer(struct rspi_data *rspi, const u8 *tx, u8 *rx,
+                            unsigned int n)
 {
-       int ret;
-
-       ret = rspi_data_out(rspi, data);
-       if (ret < 0)
-               return ret;
+       while (n-- > 0) {
+               if (tx) {
+                       int ret = rspi_data_out(rspi, *tx++);
+                       if (ret < 0)
+                               return ret;
+               }
+               if (rx) {
+                       int ret = rspi_data_in(rspi);
+                       if (ret < 0)
+                               return ret;
+                       *rx++ = ret;
+               }
+       }
 
-       return rspi_data_in(rspi);
+       return 0;
 }
 
 static void rspi_dma_complete(void *arg)
@@ -644,13 +653,11 @@ static int rspi_is_dma(const struct rspi_data *rspi, struct spi_transfer *t)
 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;
+       int ret;
 
        spcr = rspi_read8(rspi, RSPI_SPCR);
-       if (rx_buf) {
+       if (xfer->rx_buf) {
                rspi_receive_init(rspi);
                spcr &= ~SPCR_TXMD;
        } else {
@@ -658,18 +665,9 @@ static int rspi_transfer_out_in(struct rspi_data *rspi,
        }
        rspi_write8(rspi, spcr, RSPI_SPCR);
 
-       while (remain > 0) {
-               ret = rspi_data_out(rspi, *tx_buf++);
-               if (ret < 0)
-                       return ret;
-               if (rx_buf) {
-                       ret = rspi_data_in(rspi);
-                       if (ret < 0)
-                               return ret;
-                       *rx_buf++ = ret;
-               }
-               remain--;
-       }
+       ret = rspi_pio_transfer(rspi, xfer->tx_buf, xfer->rx_buf, xfer->len);
+       if (ret < 0)
+               return ret;
 
        /* Wait for the last transmission */
        rspi_wait_for_tx_empty(rspi);
@@ -694,19 +692,13 @@ static int rspi_transfer_one(struct spi_master *master, struct spi_device *spi,
 static int rspi_rz_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;
+       int ret;
 
        rspi_rz_receive_init(rspi);
 
-       while (remain > 0) {
-               ret = rspi_data_out_in(rspi, *tx_buf++);
-               if (ret < 0)
-                       return ret;
-               *rx_buf++ = ret;
-               remain--;
-       }
+       ret = rspi_pio_transfer(rspi, xfer->tx_buf, xfer->rx_buf, xfer->len);
+       if (ret < 0)
+               return ret;
 
        /* Wait for the last transmission */
        rspi_wait_for_tx_empty(rspi);
@@ -726,19 +718,13 @@ static int rspi_rz_transfer_one(struct spi_master *master,
 static int qspi_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;
+       int ret;
 
        qspi_receive_init(rspi);
 
-       while (remain > 0) {
-               ret = rspi_data_out_in(rspi, *tx_buf++);
-               if (ret < 0)
-                       return ret;
-               *rx_buf++ = ret;
-               remain--;
-       }
+       ret = rspi_pio_transfer(rspi, xfer->tx_buf, xfer->rx_buf, xfer->len);
+       if (ret < 0)
+               return ret;
 
        /* Wait for the last transmission */
        rspi_wait_for_tx_empty(rspi);
@@ -748,15 +734,11 @@ static int qspi_transfer_out_in(struct rspi_data *rspi,
 
 static int qspi_transfer_out(struct rspi_data *rspi, struct spi_transfer *xfer)
 {
-       const u8 *buf = xfer->tx_buf;
-       unsigned int i;
        int ret;
 
-       for (i = 0; i < xfer->len; i++) {
-               ret = rspi_data_out(rspi, *buf++);
-               if (ret < 0)
-                       return ret;
-       }
+       ret = rspi_pio_transfer(rspi, xfer->tx_buf, NULL, xfer->len);
+       if (ret < 0)
+               return ret;
 
        /* Wait for the last transmission */
        rspi_wait_for_tx_empty(rspi);
@@ -766,18 +748,7 @@ static int qspi_transfer_out(struct rspi_data *rspi, struct spi_transfer *xfer)
 
 static int qspi_transfer_in(struct rspi_data *rspi, struct spi_transfer *xfer)
 {
-       u8 *buf = xfer->rx_buf;
-       unsigned int i;
-       int ret;
-
-       for (i = 0; i < xfer->len; i++) {
-               ret = rspi_data_in(rspi);
-               if (ret < 0)
-                       return ret;
-               *buf++ = ret;
-       }
-
-       return 0;
+       return rspi_pio_transfer(rspi, NULL, xfer->rx_buf, xfer->len);
 }
 
 static int qspi_transfer_one(struct spi_master *master, struct spi_device *spi,