[PATCH v2 1/4] spi: mediatek: fix spi incorrect endian usage

From: Leilk Liu
Date: Thu Aug 20 2015 - 05:20:14 EST


TX_ENDIAN/RX_ENDIAN bits define whether to reverse the endian
order of the data DMA from/to memory. The endian order should
keep the same with cpu endian.

Signed-off-by: Leilk Liu <leilk.liu@xxxxxxxxxxxx>
---
drivers/spi/spi-mt65xx.c | 38 ++++++++++++++------------------
include/linux/platform_data/spi-mt65xx.h | 2 --
2 files changed, 16 insertions(+), 24 deletions(-)

diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index 321b820..79286c8 100644
--- a/drivers/spi/spi-mt65xx.c
+++ b/drivers/spi/spi-mt65xx.c
@@ -122,8 +122,6 @@ static const struct mtk_spi_compatible mt8173_compat = {
static const struct mtk_chip_config mtk_default_chip_info = {
.rx_mlsb = 1,
.tx_mlsb = 1,
- .tx_endian = 0,
- .rx_endian = 0,
};

static const struct of_device_id mtk_spi_of_match[] = {
@@ -161,9 +159,13 @@ static void mtk_spi_config(struct mtk_spi *mdata,
reg_val |= (chip_config->rx_mlsb << SPI_CMD_RXMSBF_OFFSET);

/* set the tx/rx endian */
- reg_val &= ~(SPI_CMD_TX_ENDIAN | SPI_CMD_RX_ENDIAN);
- reg_val |= (chip_config->tx_endian << SPI_CMD_TX_ENDIAN_OFFSET);
- reg_val |= (chip_config->rx_endian << SPI_CMD_RX_ENDIAN_OFFSET);
+#ifdef __LITTLE_ENDIAN
+ reg_val &= ~SPI_CMD_TX_ENDIAN;
+ reg_val &= ~SPI_CMD_RX_ENDIAN;
+#else
+ reg_val |= SPI_CMD_TX_ENDIAN;
+ reg_val |= SPI_CMD_RX_ENDIAN;
+#endif

/* set finish and pause interrupt always enable */
reg_val |= SPI_CMD_FINISH_IE | SPI_CMD_PAUSE_EN;
@@ -352,7 +354,7 @@ static int mtk_spi_fifo_transfer(struct spi_master *master,
struct spi_device *spi,
struct spi_transfer *xfer)
{
- int cnt, i;
+ int cnt;
struct mtk_spi *mdata = spi_master_get_devdata(master);

mdata->cur_transfer = xfer;
@@ -364,10 +366,7 @@ static int mtk_spi_fifo_transfer(struct spi_master *master,
cnt = xfer->len / 4 + 1;
else
cnt = xfer->len / 4;
-
- for (i = 0; i < cnt; i++)
- writel(*((u32 *)xfer->tx_buf + i),
- mdata->base + SPI_TX_DATA_REG);
+ iowrite32_rep(mdata->base + SPI_TX_DATA_REG, xfer->tx_buf, cnt);

mtk_spi_enable_transfer(master);

@@ -437,7 +436,7 @@ static bool mtk_spi_can_dma(struct spi_master *master,

static irqreturn_t mtk_spi_interrupt(int irq, void *dev_id)
{
- u32 cmd, reg_val, i;
+ u32 cmd, reg_val, cnt;
struct spi_master *master = dev_id;
struct mtk_spi *mdata = spi_master_get_devdata(master);
struct spi_transfer *trans = mdata->cur_transfer;
@@ -449,18 +448,13 @@ static irqreturn_t mtk_spi_interrupt(int irq, void *dev_id)
mdata->state = MTK_SPI_IDLE;

if (!master->can_dma(master, master->cur_msg->spi, trans)) {
- /* xfer len is not N*4 bytes every time in a transfer,
- * but SPI_RX_DATA_REG must reads 4 bytes once,
- * so rx buffer byte by byte.
- */
if (trans->rx_buf) {
- for (i = 0; i < mdata->xfer_len; i++) {
- if (i % 4 == 0)
- reg_val =
- readl(mdata->base + SPI_RX_DATA_REG);
- *((u8 *)(trans->rx_buf + i)) =
- (reg_val >> ((i % 4) * 8)) & 0xff;
- }
+ if (mdata->xfer_len % 4)
+ cnt = mdata->xfer_len / 4 + 1;
+ else
+ cnt = mdata->xfer_len / 4;
+ ioread32_rep(mdata->base + SPI_RX_DATA_REG,
+ trans->rx_buf, cnt);
}
spi_finalize_current_transfer(master);
return IRQ_HANDLED;
diff --git a/include/linux/platform_data/spi-mt65xx.h b/include/linux/platform_data/spi-mt65xx.h
index 7512255..54b0448 100644
--- a/include/linux/platform_data/spi-mt65xx.h
+++ b/include/linux/platform_data/spi-mt65xx.h
@@ -16,7 +16,5 @@
struct mtk_chip_config {
u32 tx_mlsb;
u32 rx_mlsb;
- u32 tx_endian;
- u32 rx_endian;
};
#endif
--
1.8.1.1.dirty

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