return t->len - count;
}
-static int
-bitbang_transfer_setup(struct spi_device *spi, struct spi_transfer *t)
+int spi_bitbang_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
{
struct spi_bitbang_cs *cs = spi->controller_state;
u8 bits_per_word;
/* nsecs = (clock period)/2 */
if (!hz)
hz = spi->max_speed_hz;
- cs->nsecs = (1000000000/2) / hz;
- if (cs->nsecs > MAX_UDELAY_MS * 1000)
- return -EINVAL;
+ if (hz) {
+ cs->nsecs = (1000000000/2) / hz;
+ if (cs->nsecs > (MAX_UDELAY_MS * 1000 * 1000))
+ return -EINVAL;
+ }
return 0;
}
+EXPORT_SYMBOL_GPL(spi_bitbang_setup_transfer);
/**
* spi_bitbang_setup - default setup for per-word I/O loops
struct spi_bitbang *bitbang;
int retval;
- if (!spi->max_speed_hz)
+ bitbang = spi_master_get_devdata(spi->master);
+
+ /* REVISIT: some systems will want to support devices using lsb-first
+ * bit encodings on the wire. In pure software that would be trivial,
+ * just bitbang_txrx_le_cphaX() routines shifting the other way, and
+ * some hardware controllers also have this support.
+ */
+ if ((spi->mode & SPI_LSB_FIRST) != 0)
return -EINVAL;
if (!cs) {
return -ENOMEM;
spi->controller_state = cs;
}
- bitbang = spi_master_get_devdata(spi->master);
if (!spi->bits_per_word)
spi->bits_per_word = 8;
if (!cs->txrx_word)
return -EINVAL;
- retval = bitbang_transfer_setup(spi, NULL);
+ retval = spi_bitbang_setup_transfer(spi, NULL);
if (retval < 0)
return retval;
- dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec\n",
+ dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec/bit\n",
__FUNCTION__, spi->mode & (SPI_CPOL | SPI_CPHA),
spi->bits_per_word, 2 * cs->nsecs);
{
struct spi_bitbang *bitbang;
unsigned long flags;
+ int status = 0;
m->actual_length = 0;
m->status = -EINPROGRESS;
return -ESHUTDOWN;
spin_lock_irqsave(&bitbang->lock, flags);
- list_add_tail(&m->queue, &bitbang->queue);
- queue_work(bitbang->workqueue, &bitbang->work);
+ if (!spi->max_speed_hz)
+ status = -ENETDOWN;
+ else {
+ list_add_tail(&m->queue, &bitbang->queue);
+ queue_work(bitbang->workqueue, &bitbang->work);
+ }
spin_unlock_irqrestore(&bitbang->lock, flags);
- return 0;
+ return status;
}
EXPORT_SYMBOL_GPL(spi_bitbang_transfer);
bitbang->use_dma = 0;
bitbang->txrx_bufs = spi_bitbang_bufs;
if (!bitbang->master->setup) {
- bitbang->setup_transfer = bitbang_transfer_setup;
+ if (!bitbang->setup_transfer)
+ bitbang->setup_transfer =
+ spi_bitbang_setup_transfer;
bitbang->master->setup = spi_bitbang_setup;
bitbang->master->cleanup = spi_bitbang_cleanup;
}