spi: img-spfi: Select FIFO based on transfer length

Since the 32-bit FIFO is deeper (64 bytes) than the 8-bit FIFO (16 bytes),
use the 32-bit FIFO when there are at least 32 bits remaining to be
transferred in PIO mode or when the transfer length is 32-bit aligned
in DMA mode.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 19 insertions, 30 deletions

diff --git a/drivers/spi/spi-img-spfi.c b/drivers/spi/spi-img-spfi.c
index aad6683db81b..c01567d53581 100644
--- a/drivers/spi/spi-img-spfi.c
+++ b/drivers/spi/spi-img-spfi.c
@@ -160,16 +160,16 @@ static unsigned int spfi_pio_write32(struct img_spfi *spfi, const u32 *buf,
         unsigned int count = 0;
         u32 status;
 
-        while (count < max) {
+        while (count < max / 4) {
                 spfi_writel(spfi, SPFI_INTERRUPT_SDFUL, SPFI_INTERRUPT_CLEAR);
                 status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
                 if (status & SPFI_INTERRUPT_SDFUL)
                         break;
-                spfi_writel(spfi, buf[count / 4], SPFI_TX_32BIT_VALID_DATA);
-                count += 4;
+                spfi_writel(spfi, buf[count], SPFI_TX_32BIT_VALID_DATA);
+                count++;
         }
 
-        return count;
+        return count * 4;
 }
 
 static unsigned int spfi_pio_write8(struct img_spfi *spfi, const u8 *buf,
@@ -196,17 +196,17 @@ static unsigned int spfi_pio_read32(struct img_spfi *spfi, u32 *buf,
         unsigned int count = 0;
         u32 status;
 
-        while (count < max) {
+        while (count < max / 4) {
                 spfi_writel(spfi, SPFI_INTERRUPT_GDEX32BIT,
                             SPFI_INTERRUPT_CLEAR);
                 status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
                 if (!(status & SPFI_INTERRUPT_GDEX32BIT))
                         break;
-                buf[count / 4] = spfi_readl(spfi, SPFI_RX_32BIT_VALID_DATA);
-                count += 4;
+                buf[count] = spfi_readl(spfi, SPFI_RX_32BIT_VALID_DATA);
+                count++;
         }
 
-        return count;
+        return count * 4;
 }
 
 static unsigned int spfi_pio_read8(struct img_spfi *spfi, u8 *buf,
@@ -251,17 +251,15 @@ static int img_spfi_start_pio(struct spi_master *master,
                time_before(jiffies, timeout)) {
                 unsigned int tx_count, rx_count;
 
-                switch (xfer->bits_per_word) {
-                case 32:
+                if (tx_bytes >= 4)
                         tx_count = spfi_pio_write32(spfi, tx_buf, tx_bytes);
-                        rx_count = spfi_pio_read32(spfi, rx_buf, rx_bytes);
-                        break;
-                case 8:
-                default:
+                else
                         tx_count = spfi_pio_write8(spfi, tx_buf, tx_bytes);
+
+                if (rx_bytes >= 4)
+                        rx_count = spfi_pio_read32(spfi, rx_buf, rx_bytes);
+                else
                         rx_count = spfi_pio_read8(spfi, rx_buf, rx_bytes);
-                        break;
-                }
 
                 tx_buf += tx_count;
                 rx_buf += rx_count;
@@ -331,14 +329,11 @@ static int img_spfi_start_dma(struct spi_master *master,
 
         if (xfer->rx_buf) {
                 rxconf.direction = DMA_DEV_TO_MEM;
-                switch (xfer->bits_per_word) {
-                case 32:
+                if (xfer->len % 4 == 0) {
                         rxconf.src_addr = spfi->phys + SPFI_RX_32BIT_VALID_DATA;
                         rxconf.src_addr_width = 4;
                         rxconf.src_maxburst = 4;
-                        break;
-                case 8:
-                default:
+                } else {
                         rxconf.src_addr = spfi->phys + SPFI_RX_8BIT_VALID_DATA;
                         rxconf.src_addr_width = 1;
                         rxconf.src_maxburst = 4;
@@ -358,18 +353,14 @@ static int img_spfi_start_dma(struct spi_master *master,
 
         if (xfer->tx_buf) {
                 txconf.direction = DMA_MEM_TO_DEV;
-                switch (xfer->bits_per_word) {
-                case 32:
+                if (xfer->len % 4 == 0) {
                         txconf.dst_addr = spfi->phys + SPFI_TX_32BIT_VALID_DATA;
                         txconf.dst_addr_width = 4;
                         txconf.dst_maxburst = 4;
-                        break;
-                case 8:
-                default:
+                } else {
                         txconf.dst_addr = spfi->phys + SPFI_TX_8BIT_VALID_DATA;
                         txconf.dst_addr_width = 1;
                         txconf.dst_maxburst = 4;
-                        break;
                 }
                 dmaengine_slave_config(spfi->tx_ch, &txconf);
 
@@ -508,9 +499,7 @@ static void img_spfi_set_cs(struct spi_device *spi, bool enable)
 static bool img_spfi_can_dma(struct spi_master *master, struct spi_device *spi,
                              struct spi_transfer *xfer)
 {
-        if (xfer->bits_per_word == 8 && xfer->len > SPFI_8BIT_FIFO_SIZE)
-                return true;
-        if (xfer->bits_per_word == 32 && xfer->len > SPFI_32BIT_FIFO_SIZE)
+        if (xfer->len > SPFI_32BIT_FIFO_SIZE)
                 return true;
         return false;
 }