From cf86874bb9bdb99ba3620428b59b0408fbc703d0 Mon Sep 17 00:00:00 2001 From: Clark Wang Date: Fri, 7 Dec 2018 02:50:38 +0000 Subject: [PATCH] spi: lpspi: Let watermark change with send data length Configure watermark to change with the length of the sent data. Support LPSPI sending message shorter than tx/rxfifosize. Signed-off-by: Clark Wang Signed-off-by: Mark Brown --- 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 cbf165e7bd17..08dcc3c22e88 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); } -- 2.30.2