diff options
Diffstat (limited to 'drivers/spi/spi_bitbang.c')
| -rw-r--r-- | drivers/spi/spi_bitbang.c | 40 |
1 files changed, 18 insertions, 22 deletions
diff --git a/drivers/spi/spi_bitbang.c b/drivers/spi/spi_bitbang.c index 85e61f451218..f1db395dd889 100644 --- a/drivers/spi/spi_bitbang.c +++ b/drivers/spi/spi_bitbang.c @@ -188,12 +188,6 @@ int spi_bitbang_setup(struct spi_device *spi) bitbang = spi_master_get_devdata(spi->master); - /* Bitbangers can support SPI_CS_HIGH, SPI_3WIRE, and so on; - * add those to master->flags, and provide the other support. - */ - if ((spi->mode & ~(SPI_CPOL|SPI_CPHA|bitbang->flags)) != 0) - return -EINVAL; - if (!cs) { cs = kzalloc(sizeof *cs, GFP_KERNEL); if (!cs) @@ -201,9 +195,6 @@ int spi_bitbang_setup(struct spi_device *spi) spi->controller_state = cs; } - if (!spi->bits_per_word) - spi->bits_per_word = 8; - /* per-word shift register access, in hardware or bitbanging */ cs->txrx_word = bitbang->txrx_word[spi->mode & (SPI_CPOL|SPI_CPHA)]; if (!cs->txrx_word) @@ -213,9 +204,7 @@ int spi_bitbang_setup(struct spi_device *spi) if (retval < 0) return retval; - dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec/bit\n", - __func__, spi->mode & (SPI_CPOL | SPI_CPHA), - spi->bits_per_word, 2 * cs->nsecs); + 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 @@ -269,6 +258,11 @@ static void bitbang_work(struct work_struct *work) struct spi_bitbang *bitbang = container_of(work, struct spi_bitbang, work); unsigned long flags; + int do_setup = -1; + int (*setup_transfer)(struct spi_device *, + struct spi_transfer *); + + setup_transfer = bitbang->setup_transfer; spin_lock_irqsave(&bitbang->lock, flags); bitbang->busy = 1; @@ -280,8 +274,6 @@ static void bitbang_work(struct work_struct *work) unsigned tmp; unsigned cs_change; int status; - int (*setup_transfer)(struct spi_device *, - struct spi_transfer *); m = container_of(bitbang->queue.next, struct spi_message, queue); @@ -298,19 +290,19 @@ static void bitbang_work(struct work_struct *work) tmp = 0; cs_change = 1; status = 0; - setup_transfer = NULL; list_for_each_entry (t, &m->transfers, transfer_list) { - /* override or restore speed and wordsize */ - if (t->speed_hz || t->bits_per_word) { - setup_transfer = bitbang->setup_transfer; + /* override speed or wordsize? */ + if (t->speed_hz || t->bits_per_word) + do_setup = 1; + + /* init (-1) or override (1) transfer params */ + if (do_setup != 0) { if (!setup_transfer) { status = -ENOPROTOOPT; break; } - } - if (setup_transfer) { status = setup_transfer(spi, t); if (status < 0) break; @@ -374,9 +366,10 @@ static void bitbang_work(struct work_struct *work) m->status = status; m->complete(m->context); - /* restore speed and wordsize */ - if (setup_transfer) + /* restore speed and wordsize if it was overridden */ + if (do_setup == 1) setup_transfer(spi, NULL); + do_setup = 0; /* normally deactivate chipselect ... unless no error and * cs_change has hinted that the next message will probably @@ -457,6 +450,9 @@ int spi_bitbang_start(struct spi_bitbang *bitbang) spin_lock_init(&bitbang->lock); INIT_LIST_HEAD(&bitbang->queue); + if (!bitbang->master->mode_bits) + bitbang->master->mode_bits = SPI_CPOL | SPI_CPHA | bitbang->flags; + if (!bitbang->master->transfer) bitbang->master->transfer = spi_bitbang_transfer; if (!bitbang->txrx_bufs) { |