Merge tag 'spi-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi updates from Mark Brown:
 "The main thing this release has been a lot of work on the integration
  with SPI NOR flashes, there's been some specific support for a while
  for controller features designed to make them perform better but it's
  not worked out as well as hoped so the interface has been redesigned
  in a way that will hopefully do better - it's already been adopted by
  a number of additional controllers so things are looking good.

  Otherwise most of the work has been driver specific:

   - Support for better integration with NOR flashes from Boris
     Brezillon and Yogesh Narayan Gaur plus usage of it in several
     drivers.

   - A big cleanup of the Rockchip driver from Emil Renner Berthing.

   - Lots of performance improvements for bcm2835 from Lukas Wunner.

   - Slave mode support for pxa2xx from Lubomir Rintel.

   - Support for Macronix MXIC, Mediatek MT7629 and MT8183, NPCM PSPI,
     and Renesas r8a77470"

* tag 'spi-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (90 commits)
  spi: sh-msiof: Reduce the number of times write to and perform the transmission from FIFO
  spi: sh-msiof: Add r8a774c0 support
  doc: lpspi: Document DT bindings for LPSPI slave mode
  spi: lpspi: Let watermark change with send data length
  spi: lpspi: Add slave mode support
  spi: lpspi: Replace all "master" with "controller"
  spi: imx: drop useless member speed_hz from driver data struct
  spi: imx: rename config callback and add useful parameters
  spi: imx: style fixes
  spi: imx: mx51-ecspi: Move some initialisation to prepare_message hook.
  spi: imx: add a device specific prepare_message callback
  mtd: atmel-quadspi: disallow building on ebsa110
  spi: Update NPCM PSPI controller documentation
  spi: npcm: Modify pspi send function
  spi: Use of_node_name_eq for node name comparisons
  spi: dw-mmio: add ACPI support
  spi: bcm2835: Synchronize with callback on DMA termination
  spi: bcm2835: Speed up FIFO access if fill level is known
  spi: bcm2835: Polish transfer of DMA prologue
  spi: spi-mem: add support for octal mode I/O data transfer
  ...

1 files changed, 21 insertions, 3 deletions

diff --git a/drivers/spi/spi-gpio.c b/drivers/spi/spi-gpio.c
index 45973ee3ae11..a4aee26028cd 100644
--- a/drivers/spi/spi-gpio.c
+++ b/drivers/spi/spi-gpio.c
@@ -256,11 +256,29 @@ static int spi_gpio_setup(struct spi_device *spi)
 static int spi_gpio_set_direction(struct spi_device *spi, bool output)
 {
 	struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);
+	int ret;
 
 	if (output)
 		return gpiod_direction_output(spi_gpio->mosi, 1);
-	else
-		return gpiod_direction_input(spi_gpio->mosi);
+
+	ret = gpiod_direction_input(spi_gpio->mosi);
+	if (ret)
+		return ret;
+	/*
+	 * Send a turnaround high impedance cycle when switching
+	 * from output to input. Theoretically there should be
+	 * a clock delay here, but as has been noted above, the
+	 * nsec delay function for bit-banged GPIO is simply
+	 * {} because bit-banging just doesn't get fast enough
+	 * anyway.
+	 */
+	if (spi->mode & SPI_3WIRE_HIZ) {
+		gpiod_set_value_cansleep(spi_gpio->sck,
+					 !(spi->mode & SPI_CPOL));
+		gpiod_set_value_cansleep(spi_gpio->sck,
+					 !!(spi->mode & SPI_CPOL));
+	}
+	return 0;
 }
 
 static void spi_gpio_cleanup(struct spi_device *spi)
@@ -410,7 +428,7 @@ static int spi_gpio_probe(struct platform_device *pdev)
 		return status;
 
 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
-	master->mode_bits = SPI_3WIRE | SPI_CPHA | SPI_CPOL;
+	master->mode_bits = SPI_3WIRE | SPI_3WIRE_HIZ | SPI_CPHA | SPI_CPOL;
 	master->flags = master_flags;
 	master->bus_num = pdev->id;
 	/* The master needs to think there is a chipselect even if not connected */