linux-kernel - [PATCH v3 1/3] spi: spi-omap2-mcspi.c: revert "Toggle CS after each word"

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Date: Wed, 27 Mar 2024 09:43:36 +0100
From: Louis Chauvet <louis.chauvet@...tlin.com>
To: Mark Brown <broonie@...nel.org>
Cc: linux-spi@...r.kernel.org, linux-kernel@...r.kernel.org, 
 thomas.petazzoni@...tlin.com, Miquel Raynal <miquel.raynal@...tlin.com>, 
 yen-mei.goh@...sight.com, koon-kee.lie@...sight.com, 
 jeremie.dautheribes@...tlin.com, Louis Chauvet <louis.chauvet@...tlin.com>
Subject: [PATCH v3 1/3] spi: spi-omap2-mcspi.c: revert "Toggle CS after
 each word"

Commit 5cbc7ca987fb ("spi: spi-omap2-mcspi.c: Toggle CS after each
word") introduced the toggling of CS after each word for the omap2-mcspi
controller.

The implementation is not respectful of the actual spi_message
content, so the CS can be raised after each word even if the
transfer structure asks to keep the CS active for the whole operation.

As it is not used anyway in the current Linux tree, it can be safely
removed.

Signed-off-by: Louis Chauvet <louis.chauvet@...tlin.com>
---
 drivers/spi/spi-omap2-mcspi.c                 | 15 ---------------
 include/linux/platform_data/spi-omap2-mcspi.h |  3 ---
 2 files changed, 18 deletions(-)

diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index ddf1c684bcc7..601acec37eca 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -1175,13 +1175,6 @@ static int omap2_mcspi_transfer_one(struct spi_controller *ctlr,
 		    t->bits_per_word == spi->bits_per_word)
 			par_override = 0;
 	}
-	if (cd && cd->cs_per_word) {
-		chconf = mcspi->ctx.modulctrl;
-		chconf &= ~OMAP2_MCSPI_MODULCTRL_SINGLE;
-		mcspi_write_reg(ctlr, OMAP2_MCSPI_MODULCTRL, chconf);
-		mcspi->ctx.modulctrl =
-			mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
-	}
 
 	chconf = mcspi_cached_chconf0(spi);
 	chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
@@ -1240,14 +1233,6 @@ static int omap2_mcspi_transfer_one(struct spi_controller *ctlr,
 		status = omap2_mcspi_setup_transfer(spi, NULL);
 	}
 
-	if (cd && cd->cs_per_word) {
-		chconf = mcspi->ctx.modulctrl;
-		chconf |= OMAP2_MCSPI_MODULCTRL_SINGLE;
-		mcspi_write_reg(ctlr, OMAP2_MCSPI_MODULCTRL, chconf);
-		mcspi->ctx.modulctrl =
-			mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
-	}
-
 	omap2_mcspi_set_enable(spi, 0);
 
 	if (spi_get_csgpiod(spi, 0))
diff --git a/include/linux/platform_data/spi-omap2-mcspi.h b/include/linux/platform_data/spi-omap2-mcspi.h
index 3b400b1919a9..9e3c15b4ac91 100644
--- a/include/linux/platform_data/spi-omap2-mcspi.h
+++ b/include/linux/platform_data/spi-omap2-mcspi.h
@@ -16,9 +16,6 @@ struct omap2_mcspi_platform_config {
 
 struct omap2_mcspi_device_config {
 	unsigned turbo_mode:1;
-
-	/* toggle chip select after every word */
-	unsigned cs_per_word:1;
 };
 
 #endif

-- 
2.43.0