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>

diff --git a/drivers/spi/spi-img-spfi.c b/drivers/spi/spi-img-spfi.c
index aad6683db81b9a0154d12d3fc71fd5d45fb8bfc3..c01567d53581c0dcdfc6fcb61e7f6e821d0e0b39 100644 (file)
--- 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;
 }