X-Git-Url: https://repo.jachan.dev/linux.git/blobdiff_plain/8ad4b6fa0f874ec8ec6e92a90116e3ab43cded6c..e12ff2876493:/drivers/spi/spi-gpio.c

diff --git a/drivers/spi/spi-gpio.c b/drivers/spi/spi-gpio.c
index 4b12c4964a66..092afc7679d4 100644
--- a/drivers/spi/spi-gpio.c
+++ b/drivers/spi/spi-gpio.c
@@ -230,7 +230,7 @@ static void spi_gpio_chipselect(struct spi_device *spi, int is_active)
 
 	/* Drive chip select line, if we have one */
 	if (spi_gpio->cs_gpios) {
-		struct gpio_desc *cs = spi_gpio->cs_gpios[spi->chip_select];
+		struct gpio_desc *cs = spi_gpio->cs_gpios[spi_get_chipselect(spi, 0)];
 
 		/* SPI chip selects are normally active-low */
 		gpiod_set_value_cansleep(cs, (spi->mode & SPI_CS_HIGH) ? is_active : !is_active);
@@ -248,7 +248,7 @@ static int spi_gpio_setup(struct spi_device *spi)
 	 * initialized from the descriptor lookup.
 	 */
 	if (spi_gpio->cs_gpios) {
-		cs = spi_gpio->cs_gpios[spi->chip_select];
+		cs = spi_gpio->cs_gpios[spi_get_chipselect(spi, 0)];
 		if (!spi->controller_state && cs)
 			status = gpiod_direction_output(cs,
 						  !(spi->mode & SPI_CS_HIGH));
@@ -268,9 +268,19 @@ static int spi_gpio_set_direction(struct spi_device *spi, bool output)
 	if (output)
 		return gpiod_direction_output(spi_gpio->mosi, 1);
 
-	ret = gpiod_direction_input(spi_gpio->mosi);
-	if (ret)
-		return ret;
+	/*
+	 * Only change MOSI to an input if using 3WIRE mode.
+	 * Otherwise, MOSI could be left floating if there is
+	 * no pull resistor connected to the I/O pin, or could
+	 * be left logic high if there is a pull-up. Transmitting
+	 * logic high when only clocking MISO data in can put some
+	 * SPI devices in to a bad state.
+	 */
+	if (spi->mode & SPI_3WIRE) {
+		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