Update Linux to v5.10.109

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz

Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c
index 7d61a3b..3d8948a 100644
--- a/drivers/spi/spi-bitbang.c
+++ b/drivers/spi/spi-bitbang.c
@@ -174,7 +174,7 @@
 }
 EXPORT_SYMBOL_GPL(spi_bitbang_setup_transfer);
 
-/**
+/*
  * spi_bitbang_setup - default setup for per-word I/O loops
  */
 int spi_bitbang_setup(struct spi_device *spi)
@@ -218,7 +218,7 @@
 }
 EXPORT_SYMBOL_GPL(spi_bitbang_setup);
 
-/**
+/*
  * spi_bitbang_cleanup - default cleanup for per-word I/O loops
  */
 void spi_bitbang_cleanup(struct spi_device *spi)
@@ -339,8 +339,20 @@
 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);
@@ -354,7 +366,12 @@
 	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;
@@ -420,7 +437,7 @@
 }
 EXPORT_SYMBOL_GPL(spi_bitbang_start);
 
-/**
+/*
  * spi_bitbang_stop - stops the task providing spi communication
  */
 void spi_bitbang_stop(struct spi_bitbang *bitbang)