From mboxrd@z Thu Jan 1 00:00:00 1970 From: Clark Wang Subject: [PATCH V3 3/4] spi: lpspi: Let watermark change with send data length Date: Fri, 7 Dec 2018 02:50:38 +0000 Message-ID: <20181207024924.6315-4-xiaoning.wang@nxp.com> References: <20181207024924.6315-1-xiaoning.wang@nxp.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Cc: "linux-spi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Clark Wang To: "broonie@kernel.org" Return-path: In-Reply-To: <20181207024924.6315-1-xiaoning.wang@nxp.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-spi.vger.kernel.org Configure watermark to change with the length of the sent data. Support LPSPI sending message shorter than tx/rxfifosize. Signed-off-by: Clark Wang --- 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 *); =20 u32 remain; + u8 watermark; u8 txfifosize; u8 rxfifosize; =20 @@ -235,7 +236,7 @@ static void fsl_lpspi_set_watermark(struct fsl_lpspi_da= ta *fsl_lpspi) { u32 temp; =20 - temp =3D fsl_lpspi->txfifosize >> 1 | (fsl_lpspi->rxfifosize >> 1) << 16; + temp =3D fsl_lpspi->watermark >> 1 | (fsl_lpspi->watermark >> 1) << 16; =20 writel(temp, fsl_lpspi->base + IMX7ULP_FCR); =20 @@ -261,7 +262,8 @@ static int fsl_lpspi_set_bitrate(struct fsl_lpspi_data = *fsl_lpspi) if (prescale =3D=3D 8 && scldiv >=3D 256) return -EINVAL; =20 - writel(scldiv, fsl_lpspi->base + IMX7ULP_CCR); + writel(scldiv | (scldiv << 8) | ((scldiv >> 1) << 16), + fsl_lpspi->base + IMX7ULP_CCR); =20 dev_dbg(fsl_lpspi->dev, "perclk=3D%d, speed=3D%d, prescale =3D%d, scldiv= =3D%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 =3D fsl_lpspi_buf_tx_u32; } =20 + if (t->len <=3D fsl_lpspi->txfifosize) + fsl_lpspi->watermark =3D t->len; + else + fsl_lpspi->watermark =3D fsl_lpspi->txfifosize; + fsl_lpspi_config(fsl_lpspi); } =20 --=20 2.17.1