spi: imx: fix the burst length at DMA mode and CPU mode

[ Upstream commit c712c05e46c8ce550842951e9e2606e24dbf0475 ]

For DMA mode, the bus width of the DMA is equal to the size of data
word, so burst length should be configured as bits per word.

For CPU mode, because of the spi transfer len is in byte, so calculate
the total number of words according to spi transfer len and bits per
word, burst length should be configured as total data bits.

Signed-off-by: Carlos Song <carlos.song@nxp.com>
Reviewed-by: Clark Wang <xiaoning.wang@nxp.com>
Fixes: e9b220aeacf1 ("spi: spi-imx: correctly configure burst length when using dma")
Fixes: 5f66db08cbd3 ("spi: imx: Take in account bits per word instead of assuming 8-bits")
Link: https://lore.kernel.org/r/20240204091912.36488-1-carlos.song@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 272bc871a848b833e6e673740f4be5f8f3a16294..e2d3e3ec137890d66791581599be563780dea906 100644 (file)
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -2,6 +2,7 @@
 // Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
 // Copyright (C) 2008 Juergen Beisert
 
+#include <linux/bits.h>
 #include <linux/clk.h>
 #include <linux/completion.h>
 #include <linux/delay.h>
@@ -660,15 +661,15 @@ static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx,
                        << MX51_ECSPI_CTRL_BL_OFFSET;
        else {
                if (spi_imx->usedma) {
-                       ctrl |= (spi_imx->bits_per_word *
-                               spi_imx_bytes_per_word(spi_imx->bits_per_word) - 1)
+                       ctrl |= (spi_imx->bits_per_word - 1)
                                << MX51_ECSPI_CTRL_BL_OFFSET;
                } else {
                        if (spi_imx->count >= MX51_ECSPI_CTRL_MAX_BURST)
-                               ctrl |= (MX51_ECSPI_CTRL_MAX_BURST - 1)
+                               ctrl |= (MX51_ECSPI_CTRL_MAX_BURST * BITS_PER_BYTE - 1)
                                                << MX51_ECSPI_CTRL_BL_OFFSET;
                        else
-                               ctrl |= (spi_imx->count * spi_imx->bits_per_word - 1)
+                               ctrl |= spi_imx->count / DIV_ROUND_UP(spi_imx->bits_per_word,
+                                               BITS_PER_BYTE) * spi_imx->bits_per_word
                                                << MX51_ECSPI_CTRL_BL_OFFSET;
                }
        }