diff options
Diffstat (limited to 'drivers/spi/spi-bitbang.c')
| -rw-r--r-- | drivers/spi/spi-bitbang.c | 79 |
1 files changed, 41 insertions, 38 deletions
diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c index dd9a8c54a693..d84e22dd6f9f 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> @@ -335,6 +326,42 @@ 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 +395,9 @@ 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 @@ -403,7 +406,7 @@ int spi_bitbang_start(struct spi_bitbang *bitbang) if (ret) spi_master_put(master); - return 0; + return ret; } EXPORT_SYMBOL_GPL(spi_bitbang_start); |