spi: microchip-core: Refactor FIFO read and write handlers

Make both handlers to be shorter and easier to understand.
While at it, unify their style.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Prajna Rajendra Kumar <prajna.rajendrakumar@microchip.com>
Link: https://patch.msgid.link/20251127190031.2998705-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-microchip-core-spi.c b/drivers/spi/spi-microchip-core-spi.c
index 892f066f0074bc0c1e1c13883f09e546b7b04dde..98bf0e6cd00e18df808b8815b33b53286dea842b 100644 (file)
--- a/drivers/spi/spi-microchip-core-spi.c
+++ b/drivers/spi/spi-microchip-core-spi.c
@@ -97,15 +97,12 @@ static inline void mchp_corespi_read_fifo(struct mchp_corespi *spi, u32 fifo_max
                       MCHP_CORESPI_STATUS_RXFIFO_EMPTY)
                        ;
 
+               /* On TX-only transfers always perform a dummy read */
                data = readb(spi->regs + MCHP_CORESPI_REG_RXDATA);
+               if (spi->rx_buf)
+                       *spi->rx_buf++ = data;
 
                spi->rx_len--;
-               if (!spi->rx_buf)
-                       continue;
-
-               *spi->rx_buf = data;
-
-               spi->rx_buf++;
        }
 }
 
@@ -127,23 +124,19 @@ static void mchp_corespi_disable_ints(struct mchp_corespi *spi)
 
 static inline void mchp_corespi_write_fifo(struct mchp_corespi *spi, u32 fifo_max)
 {
-       int i = 0;
-
-       while ((i < fifo_max) &&
-              !(readb(spi->regs + MCHP_CORESPI_REG_STAT) &
-                MCHP_CORESPI_STATUS_TXFIFO_FULL)) {
-               u32 word;
-
-               word = spi->tx_buf ? *spi->tx_buf : 0xaa;
-               writeb(word, spi->regs + MCHP_CORESPI_REG_TXDATA);
+       for (int i = 0; i < fifo_max; i++) {
+               if (readb(spi->regs + MCHP_CORESPI_REG_STAT) &
+                   MCHP_CORESPI_STATUS_TXFIFO_FULL)
+                       break;
 
+               /* On RX-only transfers always perform a dummy write */
                if (spi->tx_buf)
-                       spi->tx_buf++;
+                       writeb(*spi->tx_buf++, spi->regs + MCHP_CORESPI_REG_TXDATA);
+               else
+                       writeb(0xaa, spi->regs + MCHP_CORESPI_REG_TXDATA);
 
-               i++;
+               spi->tx_len--;
        }
-
-       spi->tx_len -= i;
 }
 
 static void mchp_corespi_set_cs(struct spi_device *spi, bool disable)