Thread (4 messages) 4 messages, 3 authors, 2021-07-23
STALE1769d LANDED

[PATCH] spi: mediatek: fix fifo rx mode

From: Frank Wunderlich <hidden>
Date: 2021-07-06 12:41:53
Also in: linux-mediatek, linux-spi, lkml
Subsystem: spi subsystem, the rest · Maintainers: Mark Brown, Linus Torvalds

From: Peter Hess <redacted>

In FIFO mode were two problems:
- RX mode was never handled and
- in this case the tx_buf pointer was NULL and caused an exception

fix this by handling RX mode in mtk_spi_fifo_transfer

Fixes: a568231f4632 ("spi: mediatek: Add spi bus for Mediatek MT8173")
Signed-off-by: Peter Hess <redacted>
Signed-off-by: Frank Wunderlich <redacted>
---
 drivers/spi/spi-mt65xx.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index 976f73b9e299..8d5fa7f1e506 100644
--- a/drivers/spi/spi-mt65xx.c
+++ b/drivers/spi/spi-mt65xx.c
@@ -427,13 +427,23 @@ static int mtk_spi_fifo_transfer(struct spi_master *master,
 	mtk_spi_setup_packet(master);
 
 	cnt = xfer->len / 4;
-	iowrite32_rep(mdata->base + SPI_TX_DATA_REG, xfer->tx_buf, cnt);
+	if (xfer->tx_buf)
+		iowrite32_rep(mdata->base + SPI_TX_DATA_REG, xfer->tx_buf, cnt);
+
+	if (xfer->rx_buf)
+		ioread32_rep(mdata->base + SPI_RX_DATA_REG, xfer->rx_buf, cnt);
 
 	remainder = xfer->len % 4;
 	if (remainder > 0) {
 		reg_val = 0;
-		memcpy(&reg_val, xfer->tx_buf + (cnt * 4), remainder);
-		writel(reg_val, mdata->base + SPI_TX_DATA_REG);
+		if (xfer->tx_buf) {
+			memcpy(&reg_val, xfer->tx_buf + (cnt * 4), remainder);
+			writel(reg_val, mdata->base + SPI_TX_DATA_REG);
+		}
+		if (xfer->rx_buf) {
+			reg_val = readl(mdata->base + SPI_RX_DATA_REG);
+			memcpy(xfer->rx_buf + (cnt * 4), &reg_val, remainder);
+		}
 	}
 
 	mtk_spi_enable_transfer(master);
-- 
2.25.1


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