Merge tag 'spi-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi updates from Mark Brown:
 "Not much going on in the core for SPI this time but a reasonable
  amount of change in the drivers:

   - Removal of dmal_request_slave_channel() from Peter Ujfalusi.

   - More conversions of drivers to GPIO descriptors from Linus Walleij.

   - A big rework of the sh-msiof driver from Geert Uytterhoeven moving
     it over to the generic native chipselect support.

   - DMA support for the uniphier driver from Kunihiko Hayashi.

   - New driver support for HiSilcon v3xx SPI NOR controllers from John
     Garry"

* tag 'spi-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (52 commits)
  dt-binding: spi: add NPCM PSPI reset binding
  spi: pxa2xx: Avoid touching SSCR0_SSE on MMP2
  spi: spi-fsl-qspi: Ensure width is respected in spi-mem operations
  spi: npcm-pspi: modify reset support
  spi: npcm-pspi: improve spi transfer performance
  spi: spi-ti-qspi: fix warning
  spi: npcm-pspi: fix 16 bit send and receive support
  spi: pxa2xx: Add support for Intel Comet Lake PCH-V
  spi: fsl: simplify error path in of_fsl_spi_probe()
  spi: fsl-lpspi: fix only one cs-gpio working
  spi: spi-ti-qspi: optimize byte-transfers
  spi: spi-ti-qspi: support large flash devices
  spi: spi-qcom-qspi: Use device managed memory for clk_bulk_data
  MAINTAINERS: Add a maintainer for the HiSilicon v3xx SFC driver
  spi: Add HiSilicon v3xx SPI NOR flash controller driver
  dt-bindings: spi_atmel: add microchip,sam9x60-spi
  spi: bcm2835: Raise maximum number of slaves to 4
  spi: sh-msiof: Do not redefine STR while compile testing
  spi: rspi: Add support for GPIO chip selects
  spi: rspi: Add support for multiple native chip selects
  ...

1 files changed, 19 insertions, 2 deletions

diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c
index d84e22dd6f9f..68491a8bf7b5 100644
--- a/drivers/spi/spi-bitbang.c
+++ b/drivers/spi/spi-bitbang.c
@@ -329,8 +329,20 @@ static void spi_bitbang_set_cs(struct spi_device *spi, bool enable)
 int spi_bitbang_init(struct spi_bitbang *bitbang)
 {
 	struct spi_master *master = bitbang->master;
+	bool custom_cs;
 
-	if (!master || !bitbang->chipselect)
+	if (!master)
+		return -EINVAL;
+	/*
+	 * We only need the chipselect callback if we are actually using it.
+	 * If we just use GPIO descriptors, it is surplus. If the
+	 * SPI_MASTER_GPIO_SS flag is set, we always need to call the
+	 * driver-specific chipselect routine.
+	 */
+	custom_cs = (!master->use_gpio_descriptors ||
+		     (master->flags & SPI_MASTER_GPIO_SS));
+
+	if (custom_cs && !bitbang->chipselect)
 		return -EINVAL;
 
 	mutex_init(&bitbang->lock);
@@ -344,7 +356,12 @@ int spi_bitbang_init(struct spi_bitbang *bitbang)
 	master->prepare_transfer_hardware = spi_bitbang_prepare_hardware;
 	master->unprepare_transfer_hardware = spi_bitbang_unprepare_hardware;
 	master->transfer_one = spi_bitbang_transfer_one;
-	master->set_cs = spi_bitbang_set_cs;
+	/*
+	 * When using GPIO descriptors, the ->set_cs() callback doesn't even
+	 * get called unless SPI_MASTER_GPIO_SS is set.
+	 */
+	if (custom_cs)
+		master->set_cs = spi_bitbang_set_cs;
 
 	if (!bitbang->txrx_bufs) {
 		bitbang->use_dma = 0;