linux-spi.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Esben Haabendal <esben.haabendal@gmail.com>
To: Mark Brown <broonie@kernel.org>, linux-spi@vger.kernel.org
Cc: "Kurt Kanzenbach" <kurt@linutronix.de>,
	"Angelo Dureghello" <angelo@sysam.it>,
	"Nikita Yushchenko" <nikita.yoush@cogentembedded.com>,
	"Sanchayan Maity" <maitysanchayan@gmail.com>,
	"Yuan Yao" <yao.yuan@nxp.com>,
	linux-kernel@vger.kernel.org, "Esben Haabendal" <eha@deif.com>,
	"Martin Hundebøll" <martin@geanix.com>
Subject: [PATCH 07/12] spi: spi-fsl-dspi: Fix MCR register handling
Date: Wed, 20 Jun 2018 09:34:37 +0200	[thread overview]
Message-ID: <20180620073442.20913-8-esben.haabendal@gmail.com> (raw)
In-Reply-To: <20180620073442.20913-1-esben.haabendal@gmail.com>

From: Esben Haabendal <eha@deif.com>

The MCR register is not changed, so initialize it in dspi_init().

The exception is the CLR_TXF and CLR_RXF bits, which should be written to
before each transfer to make sure we start with empty FIFOs.  With MCR
register now configured as volatile, the regmap_update_bits will do a real
read-modify-write cycle.

Signed-off-by: Esben Haabendal <eha@deif.com>
Cc: Martin Hundebøll <martin@geanix.com>
---
 drivers/spi/spi-fsl-dspi.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index 5c5905b6509f..d83d3496d538 100644
--- a/drivers/spi/spi-fsl-dspi.c
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -120,7 +120,6 @@
 #define DMA_COMPLETION_TIMEOUT	msecs_to_jiffies(3000)
 
 struct chip_data {
-	u32 mcr_val;
 	u32 ctar_val;
 	u16 void_write_data;
 };
@@ -644,10 +643,9 @@ static int dspi_transfer_one_message(struct spi_master *master,
 		else
 			dspi->bytes_per_word = 2;
 
-		regmap_write(dspi->regmap, SPI_MCR, dspi->cur_chip->mcr_val);
 		regmap_update_bits(dspi->regmap, SPI_MCR,
-				SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF,
-				SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF);
+				   SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF,
+				   SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF);
 		regmap_write(dspi->regmap, SPI_CTAR(0),
 			     dspi->cur_chip->ctar_val |
 			     SPI_FRAME_BITS(transfer->bits_per_word));
@@ -725,9 +723,6 @@ static int dspi_setup(struct spi_device *spi)
 		sck_cs_delay = pdata->sck_cs_delay;
 	}
 
-	chip->mcr_val = SPI_MCR_MASTER | SPI_MCR_PCSIS |
-		SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF;
-
 	chip->void_write_data = 0;
 
 	clkrate = clk_get_rate(dspi->clk);
@@ -883,6 +878,7 @@ static const struct regmap_config dspi_regmap_config = {
 
 static void dspi_init(struct fsl_dspi *dspi)
 {
+	regmap_write(dspi->regmap, SPI_MCR, SPI_MCR_MASTER | SPI_MCR_PCSIS);
 	regmap_write(dspi->regmap, SPI_SR, SPI_SR_CLEAR);
 }
 
-- 
2.17.1

  parent reply	other threads:[~2018-06-20  7:34 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-20  7:34 [PATCH 00/12] XSPI mode for LS1021A DSPI Esben Haabendal
2018-06-20  7:34 ` [PATCH 01/12] spi: spi-fsl-dspi: Drop unreachable else if statement Esben Haabendal
2018-06-20  8:40   ` Martin Hundebøll
2018-06-20  7:34 ` [PATCH 02/12] spi: spi-fsl-dspi: Drop unneeded use of dataflags bits Esben Haabendal
2018-06-20  7:34 ` [PATCH 03/12] spi: spi-fsl-dspi: Fix per transfer cs_change handling Esben Haabendal
2018-06-20 13:27   ` Mark Brown
2018-06-20 13:40     ` Esben Haabendal
2018-06-20  7:34 ` [PATCH 04/12] spi: spi-fsl-dspi: Simplify transfer counter handling Esben Haabendal
2018-06-20  7:34 ` [PATCH 05/12] spi: spi-fsl-dspi: Support 4 to 16 bits per word transfers Esben Haabendal
2018-06-20  7:34 ` [PATCH 06/12] spi: spi-fsl-dspi: Fixup regmap configuration Esben Haabendal
2018-06-20  7:34 ` Esben Haabendal [this message]
2018-06-20  7:34 ` [PATCH 08/12] spi: spi-fsl-dspi: Add support for XSPI mode registers Esben Haabendal
2018-06-20  7:34 ` [PATCH 09/12] spi: spi-fsl-dspi: Framesize control for XSPI mode Esben Haabendal
2018-06-20  7:34 ` [PATCH 10/12] spi: spi-fsl-dspi: XSPI FIFO handling (in TCFQ mode) Esben Haabendal
2018-06-20  7:34 ` [PATCH 11/12] spi: spi-fsl-dspi: Advertise 32 bit for XSPI mode Esben Haabendal
2018-06-20  7:34 ` [PATCH 12/12] spi: spi-fsl-dspi: Enable extended SPI mode Esben Haabendal

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180620073442.20913-8-esben.haabendal@gmail.com \
    --to=esben.haabendal@gmail.com \
    --cc=angelo@sysam.it \
    --cc=broonie@kernel.org \
    --cc=eha@deif.com \
    --cc=kurt@linutronix.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-spi@vger.kernel.org \
    --cc=maitysanchayan@gmail.com \
    --cc=martin@geanix.com \
    --cc=nikita.yoush@cogentembedded.com \
    --cc=yao.yuan@nxp.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).