spi: bitbang: Use typedef for txrx_*() callbacks

With a typedef for the txrx_*() callbacks the code looks neater.
Note that typedef for a function is okay to have.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://msgid.link/r/20240517194104.747328-2-andriy.shevchenko@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-bitbang.c

@@ -38,26 +38,19 @@
  * working quickly, or testing for differences that aren't speed related.
  */
 
+typedef unsigned int (*spi_bb_txrx_bufs_fn)(struct spi_device *, spi_bb_txrx_word_fn,
+					    unsigned int, struct spi_transfer *,
+					    unsigned int);
+
 struct spi_bitbang_cs {
 	unsigned	nsecs;	/* (clock cycle time)/2 */
-	u32		(*txrx_word)(struct spi_device *spi, unsigned nsecs,
-					u32 word, u8 bits, unsigned flags);
-	unsigned	(*txrx_bufs)(struct spi_device *,
-					u32 (*txrx_word)(
-						struct spi_device *spi,
-						unsigned nsecs,
-						u32 word, u8 bits,
-						unsigned flags),
-					unsigned, struct spi_transfer *,
-					unsigned);
+	spi_bb_txrx_word_fn txrx_word;
+	spi_bb_txrx_bufs_fn txrx_bufs;
 };
 
 static unsigned bitbang_txrx_8(
 	struct spi_device	*spi,
-	u32			(*txrx_word)(struct spi_device *spi,
-					unsigned nsecs,
-					u32 word, u8 bits,
-					unsigned flags),
+	spi_bb_txrx_word_fn txrx_word,
 	unsigned		ns,
 	struct spi_transfer	*t,
 	unsigned flags
@@ -83,10 +76,7 @@ static unsigned bitbang_txrx_8(
 
 static unsigned bitbang_txrx_16(
 	struct spi_device	*spi,
-	u32			(*txrx_word)(struct spi_device *spi,
-					unsigned nsecs,
-					u32 word, u8 bits,
-					unsigned flags),
+	spi_bb_txrx_word_fn txrx_word,
 	unsigned		ns,
 	struct spi_transfer	*t,
 	unsigned flags
@@ -112,10 +102,7 @@ static unsigned bitbang_txrx_16(
 
 static unsigned bitbang_txrx_32(
 	struct spi_device	*spi,
-	u32			(*txrx_word)(struct spi_device *spi,
-					unsigned nsecs,
-					u32 word, u8 bits,
-					unsigned flags),
+	spi_bb_txrx_word_fn txrx_word,
 	unsigned		ns,
 	struct spi_transfer	*t,
 	unsigned flags

include/linux/spi/spi_bitbang.h

@@ -4,6 +4,8 @@
 
 #include <linux/workqueue.h>
 
+typedef u32 (*spi_bb_txrx_word_fn)(struct spi_device *, unsigned int, u32, u8, unsigned int);
+
 struct spi_bitbang {
 	struct mutex		lock;
 	u8			busy;
@@ -28,9 +30,8 @@ struct spi_bitbang {
 	int	(*txrx_bufs)(struct spi_device *spi, struct spi_transfer *t);
 
 	/* txrx_word[SPI_MODE_*]() just looks like a shift register */
-	u32	(*txrx_word[4])(struct spi_device *spi,
-			unsigned nsecs,
-			u32 word, u8 bits, unsigned flags);
+	spi_bb_txrx_word_fn txrx_word[4];
+
 	int	(*set_line_direction)(struct spi_device *spi, bool output);
 };