spi: Increase imx51 ecspi burst length based on transfer length

IMX51 supports 4096 bit burst lengths. Using the spi transfer length
instead of bits_per_word increases performance significantly.

Signed-off-by: Stefan Moring <stefan.moring@technolution.nl>
Link: https://lore.kernel.org/r/20230628125406.237949-1-stefan.moring@technolution.nl
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 528ae46..169d158 100644 (file)
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -659,9 +659,13 @@ static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx,
        if (spi_imx->slave_mode && is_imx53_ecspi(spi_imx))
                ctrl |= (spi_imx->slave_burst * 8 - 1)
                        << MX51_ECSPI_CTRL_BL_OFFSET;
-       else
-               ctrl |= (spi_imx->bits_per_word - 1)
-                       << MX51_ECSPI_CTRL_BL_OFFSET;
+       else {
+               if (spi_imx->count >= 512)
+                       ctrl |= 0xFFF << MX51_ECSPI_CTRL_BL_OFFSET;
+               else
+                       ctrl |= (spi_imx->count*8 - 1)
+                               << MX51_ECSPI_CTRL_BL_OFFSET;
+       }
 
        /* set clock speed */
        ctrl &= ~(0xf << MX51_ECSPI_CTRL_POSTDIV_OFFSET |
@@ -1258,6 +1262,7 @@ static int spi_imx_setupxfer(struct spi_device *spi,
                spi_imx->spi_bus_clk = t->speed_hz;
 
        spi_imx->bits_per_word = t->bits_per_word;
+       spi_imx->count = t->len;
 
        /*
         * Initialize the functions for transfer. To transfer non byte-aligned