From: Clark Wang <xiaoning.wang@nxp.com>
To: "broonie@kernel.org" <broonie@kernel.org>
Cc: "linux-spi@vger.kernel.org" <linux-spi@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Clark Wang <xiaoning.wang@nxp.com>
Subject: [PATCH V3 3/4] spi: lpspi: Let watermark change with send data length
Date: Fri, 7 Dec 2018 02:50:38 +0000 [thread overview]
Message-ID: <20181207024924.6315-4-xiaoning.wang@nxp.com> (raw)
In-Reply-To: <20181207024924.6315-1-xiaoning.wang@nxp.com>
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@nxp.com>
---
Change log:
V2/V3:
- No change.
---
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);
}
--
2.17.1
next prev parent reply other threads:[~2018-12-07 2:50 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-07 2:50 [PATCH V3 0/4] spi: lpspi: Add Slave Mode support for LPSPI Clark Wang
2018-12-07 2:50 ` [PATCH V3 1/4] spi: lpspi: Replace all "master" with "controller" Clark Wang
2018-12-08 5:14 ` Joe Perches
2018-12-08 5:42 ` Clark Wang
2018-12-07 2:50 ` [PATCH V3 2/4] spi: lpspi: Add slave mode support Clark Wang
2018-12-07 2:50 ` Clark Wang [this message]
2018-12-07 2:50 ` [PATCH V3 4/4] doc: lpspi: Document DT bindings for LPSPI slave mode Clark Wang
2018-12-13 12:09 ` Applied "doc: lpspi: Document DT bindings for LPSPI slave mode" to the spi tree Mark Brown
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