Mediatek spi HW can't set cs inactive(keep cs high) directly.
Instead, it supplies pause mode to do it indirectly. If driver
unsets SPI_CMD_PAUSE_MODE in CMD_REG, it also needs to reset
internal state machine to let cs inactive at once.
Signed-off-by: Leilk Liu <leilk.liu@xxxxxxxxxxxx>
---
drivers/spi/spi-mt65xx.c | 27 +++++++--------------------
1 file changed, 7 insertions(+), 20 deletions(-)
diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index 401e2e0..ba0fc10 100644
--- a/drivers/spi/spi-mt65xx.c
+++ b/drivers/spi/spi-mt65xx.c
@@ -173,22 +173,6 @@ static void mtk_spi_config(struct mtk_spi *mdata,
writel(mdata->pad_sel, mdata->base + SPI_PAD_SEL_REG);
}
-static int mtk_spi_prepare_hardware(struct spi_master *master)
-{
- struct spi_transfer *trans;
- struct mtk_spi *mdata = spi_master_get_devdata(master);
- struct spi_message *msg = master->cur_msg;
-
- trans = list_first_entry(&msg->transfers, struct spi_transfer,
- transfer_list);
- if (!trans->cs_change) {
- mdata->state = MTK_SPI_IDLE;
- mtk_spi_reset(mdata);
- }
-
- return 0;
-}
-
static int mtk_spi_prepare_message(struct spi_master *master,
struct spi_message *msg)
{
@@ -228,11 +212,15 @@ static void mtk_spi_set_cs(struct spi_device *spi, bool enable)
struct mtk_spi *mdata = spi_master_get_devdata(spi->master);
reg_val = readl(mdata->base + SPI_CMD_REG);
- if (!enable)
+ if (!enable) {
reg_val |= SPI_CMD_PAUSE_EN;
- else
+ writel(reg_val, mdata->base + SPI_CMD_REG);
+ } else {
reg_val &= ~SPI_CMD_PAUSE_EN;
- writel(reg_val, mdata->base + SPI_CMD_REG);
+ writel(reg_val, mdata->base + SPI_CMD_REG);
+ mdata->state = MTK_SPI_IDLE;
+ mtk_spi_reset(mdata);
+ }
}
static void mtk_spi_prepare_transfer(struct spi_master *master,
@@ -509,7 +497,6 @@ static int mtk_spi_probe(struct platform_device *pdev)
master->mode_bits = SPI_CPOL | SPI_CPHA;
master->set_cs = mtk_spi_set_cs;
- master->prepare_transfer_hardware = mtk_spi_prepare_hardware;
master->prepare_message = mtk_spi_prepare_message;
master->transfer_one = mtk_spi_transfer_one;
master->can_dma = mtk_spi_can_dma;
--
1.8.1.1.dirty
--
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