[PATCH 11/12] spi: bitbang: Introduce spi_bitbang_init()

From: Andrey Smirnov
Date: Wed Apr 03 2019 - 00:02:15 EST


Move all of the code doing struct spi_bitbang initialization, so that
it can be paired with devm_spi_register_master() in order to avoid
having to call spi_bitbang_stop() explicitly.

Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
Cc: Mark Brown <broonie@xxxxxxxxxx>
Cc: Chris Healy <cphealy@xxxxxxxxx>
Cc: linux-spi@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
drivers/spi/spi-bitbang.c | 66 +++++++++++++++++++--------------
include/linux/spi/spi_bitbang.h | 1 +
2 files changed, 40 insertions(+), 27 deletions(-)

diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c
index dd9a8c54a693..4243e53f9f7b 100644
--- a/drivers/spi/spi-bitbang.c
+++ b/drivers/spi/spi-bitbang.c
@@ -335,6 +335,42 @@ static void spi_bitbang_set_cs(struct spi_device *spi, bool enable)

/*----------------------------------------------------------------------*/

+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
@@ -368,33 +404,9 @@ int spi_bitbang_start(struct spi_bitbang *bitbang)
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
diff --git a/include/linux/spi/spi_bitbang.h b/include/linux/spi/spi_bitbang.h
index b7e021b274dc..4444c2a992cb 100644
--- a/include/linux/spi/spi_bitbang.h
+++ b/include/linux/spi/spi_bitbang.h
@@ -44,6 +44,7 @@ extern int spi_bitbang_setup_transfer(struct spi_device *spi,

/* start or stop queue processing */
extern int spi_bitbang_start(struct spi_bitbang *spi);
+extern int spi_bitbang_init(struct spi_bitbang *spi);
extern void spi_bitbang_stop(struct spi_bitbang *spi);

#endif /* __SPI_BITBANG_H */
--
2.20.1