spi: spi-fsl-lpspi: Read chip-select amount from hardware for i.MX93

PARAM.PCSNUM register on i.MX93 indicates the number of supported
(hw) chip-selects. LPSPI4 has 3 while others have only 2.
Still allow overwriting from DT.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/20230717085934.409476-3-alexander.stein@ew.tq-group.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c
index f3b7bb1..e32e8ca 100644 (file)
--- a/drivers/spi/spi-fsl-lpspi.c
+++ b/drivers/spi/spi-fsl-lpspi.c
@@ -896,8 +896,12 @@ static int fsl_lpspi_probe(struct platform_device *pdev)
        fsl_lpspi->txfifosize = 1 << (temp & 0x0f);
        fsl_lpspi->rxfifosize = 1 << ((temp >> 8) & 0x0f);
        if (of_property_read_u32((&pdev->dev)->of_node, "num-cs",
-                                &num_cs))
-               num_cs = 1;
+                                &num_cs)) {
+               if (of_device_is_compatible(pdev->dev.of_node, "fsl,imx93-spi"))
+                       num_cs = ((temp >> 16) & 0xf);
+               else
+                       num_cs = 1;
+       }
 
        controller->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 32);
        controller->transfer_one = fsl_lpspi_transfer_one;