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

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>

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 546cdce525fc5b1b49b305b872e81d2b0aed0cb5..833a1bb7a91438e02c2d5a176e1afdaba4159552 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;
                }
        }