1 files changed, 33 insertions, 4 deletions

diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index 899d7a8f0889..278867a31950 100644
--- a/drivers/spi/spi-mt65xx.c
+++ b/drivers/spi/spi-mt65xx.c
@@ -73,7 +73,7 @@
 #define MTK_SPI_IDLE 0
 #define MTK_SPI_PAUSED 1
 
-#define MTK_SPI_MAX_FIFO_SIZE 32
+#define MTK_SPI_MAX_FIFO_SIZE 32U
 #define MTK_SPI_PACKET_SIZE 1024
 
 struct mtk_spi_compatible {
@@ -333,7 +333,7 @@ static int mtk_spi_fifo_transfer(struct spi_master *master,
 	struct mtk_spi *mdata = spi_master_get_devdata(master);
 
 	mdata->cur_transfer = xfer;
-	mdata->xfer_len = xfer->len;
+	mdata->xfer_len = min(MTK_SPI_MAX_FIFO_SIZE, xfer->len);
 	mtk_spi_prepare_transfer(master, xfer);
 	mtk_spi_setup_packet(master);
 
@@ -410,7 +410,10 @@ static bool mtk_spi_can_dma(struct spi_master *master,
 			    struct spi_device *spi,
 			    struct spi_transfer *xfer)
 {
-	return xfer->len > MTK_SPI_MAX_FIFO_SIZE;
+	/* Buffers for DMA transactions must be 4-byte aligned */
+	return (xfer->len > MTK_SPI_MAX_FIFO_SIZE &&
+		(unsigned long)xfer->tx_buf % 4 == 0 &&
+		(unsigned long)xfer->rx_buf % 4 == 0);
 }
 
 static int mtk_spi_setup(struct spi_device *spi)
@@ -451,7 +454,33 @@ static irqreturn_t mtk_spi_interrupt(int irq, void *dev_id)
 					&reg_val, remainder);
 			}
 		}
-		spi_finalize_current_transfer(master);
+
+		trans->len -= mdata->xfer_len;
+		if (!trans->len) {
+			spi_finalize_current_transfer(master);
+			return IRQ_HANDLED;
+		}
+
+		if (trans->tx_buf)
+			trans->tx_buf += mdata->xfer_len;
+		if (trans->rx_buf)
+			trans->rx_buf += mdata->xfer_len;
+
+		mdata->xfer_len = min(MTK_SPI_MAX_FIFO_SIZE, trans->len);
+		mtk_spi_setup_packet(master);
+
+		cnt = trans->len / 4;
+		iowrite32_rep(mdata->base + SPI_TX_DATA_REG, trans->tx_buf, cnt);
+
+		remainder = trans->len % 4;
+		if (remainder > 0) {
+			reg_val = 0;
+			memcpy(&reg_val, trans->tx_buf + (cnt * 4), remainder);
+			writel(reg_val, mdata->base + SPI_TX_DATA_REG);
+		}
+
+		mtk_spi_enable_transfer(master);
+
 		return IRQ_HANDLED;
 	}