Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c
index f291760..d84e22d 100644
--- a/drivers/spi/spi-bitbang.c
+++ b/drivers/spi/spi-bitbang.c
@@ -1,15 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * polling/bitbanging SPI master controller driver utilities
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
  */
 
 #include <linux/spinlock.h>
@@ -213,19 +204,6 @@
 
 	dev_dbg(&spi->dev, "%s, %u nsec/bit\n", __func__, 2 * cs->nsecs);
 
-	/* NOTE we _need_ to call chipselect() early, ideally with adapter
-	 * setup, unless the hardware defaults cooperate to avoid confusion
-	 * between normal (active low) and inverted chipselects.
-	 */
-
-	/* deselect chip (low or high) */
-	mutex_lock(&bitbang->lock);
-	if (!bitbang->busy) {
-		bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
-		ndelay(cs->nsecs);
-	}
-	mutex_unlock(&bitbang->lock);
-
 	return 0;
 }
 EXPORT_SYMBOL_GPL(spi_bitbang_setup);
@@ -348,6 +326,42 @@
 
 /*----------------------------------------------------------------------*/
 
+int spi_bitbang_init(struct spi_bitbang *bitbang)
+{
+	struct spi_master *master = bitbang->master;
+
+	if (!master || !bitbang->chipselect)
+		return -EINVAL;
+
+	mutex_init(&bitbang->lock);
+
+	if (!master->mode_bits)
+		master->mode_bits = SPI_CPOL | SPI_CPHA | bitbang->flags;
+
+	if (master->transfer || master->transfer_one_message)
+		return -EINVAL;
+
+	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;
+
+	if (!bitbang->txrx_bufs) {
+		bitbang->use_dma = 0;
+		bitbang->txrx_bufs = spi_bitbang_bufs;
+		if (!master->setup) {
+			if (!bitbang->setup_transfer)
+				bitbang->setup_transfer =
+					 spi_bitbang_setup_transfer;
+			master->setup = spi_bitbang_setup;
+			master->cleanup = spi_bitbang_cleanup;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(spi_bitbang_init);
+
 /**
  * spi_bitbang_start - start up a polled/bitbanging SPI master driver
  * @bitbang: driver handle
@@ -381,33 +395,9 @@
 	struct spi_master *master = bitbang->master;
 	int ret;
 
-	if (!master || !bitbang->chipselect)
-		return -EINVAL;
-
-	mutex_init(&bitbang->lock);
-
-	if (!master->mode_bits)
-		master->mode_bits = SPI_CPOL | SPI_CPHA | bitbang->flags;
-
-	if (master->transfer || master->transfer_one_message)
-		return -EINVAL;
-
-	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;
-
-	if (!bitbang->txrx_bufs) {
-		bitbang->use_dma = 0;
-		bitbang->txrx_bufs = spi_bitbang_bufs;
-		if (!master->setup) {
-			if (!bitbang->setup_transfer)
-				bitbang->setup_transfer =
-					 spi_bitbang_setup_transfer;
-			master->setup = spi_bitbang_setup;
-			master->cleanup = spi_bitbang_cleanup;
-		}
-	}
+	ret = spi_bitbang_init(bitbang);
+	if (ret)
+		return ret;
 
 	/* driver may get busy before register() returns, especially
 	 * if someone registered boardinfo for devices
@@ -416,7 +406,7 @@
 	if (ret)
 		spi_master_put(master);
 
-	return 0;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(spi_bitbang_start);