spi: bcm-qspi: Avoid setting MSPI_CDRAM_PCS for spi-nor master

commit 5eb9a07a4ae1008b67d8bcd47bddb3dae97456b7 upstream.

Added fix for probing of spi-nor device non-zero chip selects. Set
MSPI_CDRAM_PCS (peripheral chip select) with spi master for MSPI
controller and not for MSPI/BSPI spi-nor master controller. Ensure
setting of cs bit in chip select register on chip select change.

Fixes: fa236a7ef24048 ("spi: bcm-qspi: Add Broadcom MSPI driver")
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/spi/spi-bcm-qspi.c b/drivers/spi/spi-bcm-qspi.c
index 7d629b4..77966e2 100644 (file)
--- a/drivers/spi/spi-bcm-qspi.c
+++ b/drivers/spi/spi-bcm-qspi.c
@@ -543,16 +543,19 @@ static void bcm_qspi_disable_bspi(struct bcm_qspi *qspi)
 
 static void bcm_qspi_chip_select(struct bcm_qspi *qspi, int cs)
 {
-       u32 data = 0;
+       u32 rd = 0;
+       u32 wr = 0;
 
-       if (qspi->curr_cs == cs)
-               return;
        if (qspi->base[CHIP_SELECT]) {
-               data = bcm_qspi_read(qspi, CHIP_SELECT, 0);
-               data = (data & ~0xff) | (1 << cs);
-               bcm_qspi_write(qspi, CHIP_SELECT, 0, data);
+               rd = bcm_qspi_read(qspi, CHIP_SELECT, 0);
+               wr = (rd & ~0xff) | (1 << cs);
+               if (rd == wr)
+                       return;
+               bcm_qspi_write(qspi, CHIP_SELECT, 0, wr);
                usleep_range(10, 20);
        }
+
+       dev_dbg(&qspi->pdev->dev, "using cs:%d\n", cs);
        qspi->curr_cs = cs;
 }
 
@@ -770,8 +773,13 @@ static int write_to_hw(struct bcm_qspi *qspi, struct spi_device *spi)
                        dev_dbg(&qspi->pdev->dev, "WR %04x\n", val);
                }
                mspi_cdram = MSPI_CDRAM_CONT_BIT;
-               mspi_cdram |= (~(1 << spi->chip_select) &
-                              MSPI_CDRAM_PCS);
+
+               if (has_bspi(qspi))
+                       mspi_cdram &= ~1;
+               else
+                       mspi_cdram |= (~(1 << spi->chip_select) &
+                                      MSPI_CDRAM_PCS);
+
                mspi_cdram |= ((tp.trans->bits_per_word <= 8) ? 0 :
                                MSPI_CDRAM_BITSE_BIT);