4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Clark Wang <xiaoning.wang@xxxxxxx>
[ Upstream commit cf86874bb9bdb99ba3620428b59b0408fbc703d0 ]
Configure watermark to change with the length of the sent data.
Support LPSPI sending message shorter than tx/rxfifosize.
Signed-off-by: Clark Wang <xiaoning.wang@xxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Stable-dep-of: 730bbfaf7d48 ("spi: spi-fsl-lpspi: Fix scldiv calculation")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/spi/spi-fsl-lpspi.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c
index cbf165e7bd17b..08dcc3c22e883 100644
--- a/drivers/spi/spi-fsl-lpspi.c
+++ b/drivers/spi/spi-fsl-lpspi.c
@@ -89,6 +89,7 @@ struct fsl_lpspi_data {
void (*rx)(struct fsl_lpspi_data *);
u32 remain;
+ u8 watermark;
u8 txfifosize;
u8 rxfifosize;
@@ -235,7 +236,7 @@ static void fsl_lpspi_set_watermark(struct fsl_lpspi_data *fsl_lpspi)
{
u32 temp;
- temp = fsl_lpspi->txfifosize >> 1 | (fsl_lpspi->rxfifosize >> 1) << 16;
+ temp = fsl_lpspi->watermark >> 1 | (fsl_lpspi->watermark >> 1) << 16;
writel(temp, fsl_lpspi->base + IMX7ULP_FCR);
@@ -261,7 +262,8 @@ static int fsl_lpspi_set_bitrate(struct fsl_lpspi_data *fsl_lpspi)
if (prescale == 8 && scldiv >= 256)
return -EINVAL;
- writel(scldiv, fsl_lpspi->base + IMX7ULP_CCR);
+ writel(scldiv | (scldiv << 8) | ((scldiv >> 1) << 16),
+ fsl_lpspi->base + IMX7ULP_CCR);
dev_dbg(fsl_lpspi->dev, "perclk=%d, speed=%d, prescale =%d, scldiv=%d\n",
perclk_rate, config.speed_hz, prescale, scldiv);
@@ -329,6 +331,11 @@ static void fsl_lpspi_setup_transfer(struct spi_device *spi,
fsl_lpspi->tx = fsl_lpspi_buf_tx_u32;
}
+ if (t->len <= fsl_lpspi->txfifosize)
+ fsl_lpspi->watermark = t->len;
+ else
+ fsl_lpspi->watermark = fsl_lpspi->txfifosize;
+
fsl_lpspi_config(fsl_lpspi);
}
--
2.43.0
