* Drivers can provide word-at-a-time i/o primitives, or provide
* transfer-at-a-time ones to leverage dma or fifo hardware.
*/
-static void bitbang_work(struct work_struct *work)
+
+static int spi_bitbang_prepare_hardware(struct spi_master *spi)
{
- struct spi_bitbang *bitbang =
- container_of(work, struct spi_bitbang, work);
+ struct spi_bitbang *bitbang;
unsigned long flags;
- struct spi_message *m, *_m;
+
+ bitbang = spi_master_get_devdata(spi);
spin_lock_irqsave(&bitbang->lock, flags);
bitbang->busy = 1;
- list_for_each_entry_safe(m, _m, &bitbang->queue, queue) {
- struct spi_device *spi;
- unsigned nsecs;
- struct spi_transfer *t = NULL;
- unsigned tmp;
- unsigned cs_change;
- int status;
- int do_setup = -1;
-
- list_del(&m->queue);
- spin_unlock_irqrestore(&bitbang->lock, flags);
-
- /* FIXME this is made-up ... the correct value is known to
- * word-at-a-time bitbang code, and presumably chipselect()
- * should enforce these requirements too?
- */
- nsecs = 100;
+ spin_unlock_irqrestore(&bitbang->lock, flags);
- spi = m->spi;
- tmp = 0;
- cs_change = 1;
- status = 0;
+ return 0;
+}
- list_for_each_entry (t, &m->transfers, transfer_list) {
-
- /* 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) {
- status = bitbang->setup_transfer(spi, t);
- if (status < 0)
- break;
- if (do_setup == -1)
- do_setup = 0;
- }
-
- /* set up default clock polarity, and activate chip;
- * this implicitly updates clock and spi modes as
- * previously recorded for this device via setup().
- * (and also deselects any other chip that might be
- * selected ...)
- */
- if (cs_change) {
- bitbang->chipselect(spi, BITBANG_CS_ACTIVE);
- ndelay(nsecs);
- }
- cs_change = t->cs_change;
- if (!t->tx_buf && !t->rx_buf && t->len) {
- status = -EINVAL;
- break;
- }
+static int spi_bitbang_transfer_one(struct spi_master *master,
+ struct spi_message *m)
+{
+ struct spi_bitbang *bitbang;
+ unsigned nsecs;
+ struct spi_transfer *t = NULL;
+ unsigned cs_change;
+ int status;
+ int do_setup = -1;
+ struct spi_device *spi = m->spi;
+
+ bitbang = spi_master_get_devdata(master);
+
+ /* FIXME this is made-up ... the correct value is known to
+ * word-at-a-time bitbang code, and presumably chipselect()
+ * should enforce these requirements too?
+ */
+ nsecs = 100;
- /* transfer data. the lower level code handles any
- * new dma mappings it needs. our caller always gave
- * us dma-safe buffers.
- */
- if (t->len) {
- /* REVISIT dma API still needs a designated
- * DMA_ADDR_INVALID; ~0 might be better.
- */
- if (!m->is_dma_mapped)
- t->rx_dma = t->tx_dma = 0;
- status = bitbang->txrx_bufs(spi, t);
- }
- if (status > 0)
- m->actual_length += status;
- if (status != t->len) {
- /* always report some kind of error */
- if (status >= 0)
- status = -EREMOTEIO;
+ cs_change = 1;
+ status = 0;
+
+ list_for_each_entry (t, &m->transfers, transfer_list) {
+
+ /* 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) {
+ status = bitbang->setup_transfer(spi, t);
+ if (status < 0)
break;
- }
- status = 0;
-
- /* protocol tweaks before next transfer */
- if (t->delay_usecs)
- udelay(t->delay_usecs);
-
- if (cs_change && !list_is_last(&t->transfer_list, &m->transfers)) {
- /* sometimes a short mid-message deselect of the chip
- * may be needed to terminate a mode or command
- */
- ndelay(nsecs);
- bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
- ndelay(nsecs);
- }
+ if (do_setup == -1)
+ do_setup = 0;
}
- m->status = status;
- m->complete(m->context);
+ /* set up default clock polarity, and activate chip;
+ * this implicitly updates clock and spi modes as
+ * previously recorded for this device via setup().
+ * (and also deselects any other chip that might be
+ * selected ...)
+ */
+ if (cs_change) {
+ bitbang->chipselect(spi, BITBANG_CS_ACTIVE);
+ ndelay(nsecs);
+ }
+ cs_change = t->cs_change;
+ if (!t->tx_buf && !t->rx_buf && t->len) {
+ status = -EINVAL;
+ break;
+ }
- /* normally deactivate chipselect ... unless no error and
- * cs_change has hinted that the next message will probably
- * be for this chip too.
+ /* transfer data. the lower level code handles any
+ * new dma mappings it needs. our caller always gave
+ * us dma-safe buffers.
*/
- if (!(status == 0 && cs_change)) {
+ if (t->len) {
+ /* REVISIT dma API still needs a designated
+ * DMA_ADDR_INVALID; ~0 might be better.
+ */
+ if (!m->is_dma_mapped)
+ t->rx_dma = t->tx_dma = 0;
+ status = bitbang->txrx_bufs(spi, t);
+ }
+ if (status > 0)
+ m->actual_length += status;
+ if (status != t->len) {
+ /* always report some kind of error */
+ if (status >= 0)
+ status = -EREMOTEIO;
+ break;
+ }
+ status = 0;
+
+ /* protocol tweaks before next transfer */
+ if (t->delay_usecs)
+ udelay(t->delay_usecs);
+
+ if (cs_change && !list_is_last(&t->transfer_list, &m->transfers)) {
+ /* sometimes a short mid-message deselect of the chip
+ * may be needed to terminate a mode or command
+ */
ndelay(nsecs);
bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
ndelay(nsecs);
}
+ }
+
+ m->status = status;
- spin_lock_irqsave(&bitbang->lock, flags);
+ /* normally deactivate chipselect ... unless no error and
+ * cs_change has hinted that the next message will probably
+ * be for this chip too.
+ */
+ if (!(status == 0 && cs_change)) {
+ ndelay(nsecs);
+ bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
+ ndelay(nsecs);
}
- bitbang->busy = 0;
- spin_unlock_irqrestore(&bitbang->lock, flags);
+
+ spi_finalize_current_message(master);
+
+ return status;
}
-/**
- * spi_bitbang_transfer - default submit to transfer queue
- */
-int spi_bitbang_transfer(struct spi_device *spi, struct spi_message *m)
+static int spi_bitbang_unprepare_hardware(struct spi_master *spi)
{
- struct spi_bitbang *bitbang;
+ struct spi_bitbang *bitbang;
unsigned long flags;
- int status = 0;
- m->actual_length = 0;
- m->status = -EINPROGRESS;
-
- bitbang = spi_master_get_devdata(spi->master);
+ bitbang = spi_master_get_devdata(spi);
spin_lock_irqsave(&bitbang->lock, flags);
- if (!spi->max_speed_hz)
- status = -ENETDOWN;
- else {
- list_add_tail(&m->queue, &bitbang->queue);
- queue_work(bitbang->workqueue, &bitbang->work);
- }
+ bitbang->busy = 0;
spin_unlock_irqrestore(&bitbang->lock, flags);
- return status;
+ return 0;
}
-EXPORT_SYMBOL_GPL(spi_bitbang_transfer);
/*----------------------------------------------------------------------*/
int spi_bitbang_start(struct spi_bitbang *bitbang)
{
struct spi_master *master = bitbang->master;
- int status;
if (!master || !bitbang->chipselect)
return -EINVAL;
- INIT_WORK(&bitbang->work, bitbang_work);
spin_lock_init(&bitbang->lock);
- INIT_LIST_HEAD(&bitbang->queue);
if (!master->mode_bits)
master->mode_bits = SPI_CPOL | SPI_CPHA | bitbang->flags;
- if (!master->transfer)
- master->transfer = spi_bitbang_transfer;
+ 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_message = spi_bitbang_transfer_one;
+
if (!bitbang->txrx_bufs) {
bitbang->use_dma = 0;
bitbang->txrx_bufs = spi_bitbang_bufs;
master->setup = spi_bitbang_setup;
master->cleanup = spi_bitbang_cleanup;
}
- } else if (!master->setup)
- return -EINVAL;
- if (master->transfer == spi_bitbang_transfer &&
- !bitbang->setup_transfer)
- return -EINVAL;
-
- /* this task is the only thing to touch the SPI bits */
- bitbang->busy = 0;
- bitbang->workqueue = create_singlethread_workqueue(
- dev_name(master->dev.parent));
- if (bitbang->workqueue == NULL) {
- status = -EBUSY;
- goto err1;
}
/* driver may get busy before register() returns, especially
* if someone registered boardinfo for devices
*/
- status = spi_register_master(master);
- if (status < 0)
- goto err2;
-
- return status;
-
-err2:
- destroy_workqueue(bitbang->workqueue);
-err1:
- return status;
+ return spi_register_master(master);
}
EXPORT_SYMBOL_GPL(spi_bitbang_start);
{
spi_unregister_master(bitbang->master);
- WARN_ON(!list_empty(&bitbang->queue));
-
- destroy_workqueue(bitbang->workqueue);
-
return 0;
}
EXPORT_SYMBOL_GPL(spi_bitbang_stop);
projects / karo-tx-linux.git / blobdiff