struct spi_bitbang_cs *cs = spi->controller_state;
struct spi_bitbang *bitbang;
int retval;
+ unsigned long flags;
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) {
- cs = kzalloc(sizeof *cs, SLAB_KERNEL);
+ cs = kzalloc(sizeof *cs, GFP_KERNEL);
if (!cs)
return -ENOMEM;
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)
return -EINVAL;
- retval = spi_bitbang_setup_transfer(spi, NULL);
+ retval = bitbang->setup_transfer(spi, NULL);
if (retval < 0)
return retval;
- 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);
+ 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
*/
/* deselect chip (low or high) */
- spin_lock(&bitbang->lock);
+ spin_lock_irqsave(&bitbang->lock, flags);
if (!bitbang->busy) {
bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
ndelay(cs->nsecs);
}
- spin_unlock(&bitbang->lock);
+ spin_unlock_irqrestore(&bitbang->lock, flags);
return 0;
}
/**
* spi_bitbang_cleanup - default cleanup for per-word I/O loops
*/
-void spi_bitbang_cleanup(const struct spi_device *spi)
+void spi_bitbang_cleanup(struct spi_device *spi)
{
kfree(spi->controller_state);
}
* 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(void *_bitbang)
+static void bitbang_work(struct work_struct *work)
{
- struct spi_bitbang *bitbang = _bitbang;
+ 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;
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);
tmp = 0;
cs_change = 1;
status = 0;
- setup_transfer = NULL;
list_for_each_entry (t, &m->transfers, transfer_list) {
- if (bitbang->shutdown) {
- status = -ESHUTDOWN;
- break;
- }
- /* 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;
t->rx_dma = t->tx_dma = 0;
status = bitbang->txrx_bufs(spi, t);
}
+ if (status > 0)
+ m->actual_length += status;
if (status != t->len) {
- if (status > 0)
- status = -EMSGSIZE;
+ /* always report some kind of error */
+ if (status >= 0)
+ status = -EREMOTEIO;
break;
}
- m->actual_length += status;
status = 0;
/* protocol tweaks before next transfer */
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
m->status = -EINPROGRESS;
bitbang = spi_master_get_devdata(spi->master);
- if (bitbang->shutdown)
- return -ESHUTDOWN;
spin_lock_irqsave(&bitbang->lock, flags);
if (!spi->max_speed_hz)
* hardware that basically exposes a shift register) or per-spi_transfer
* (which takes better advantage of hardware like fifos or DMA engines).
*
- * Drivers using per-word I/O loops should use (or call) spi_bitbang_setup and
- * spi_bitbang_cleanup to handle those spi master methods. Those methods are
- * the defaults if the bitbang->txrx_bufs routine isn't initialized.
+ * Drivers using per-word I/O loops should use (or call) spi_bitbang_setup,
+ * spi_bitbang_cleanup and spi_bitbang_setup_transfer to handle those spi
+ * master methods. Those methods are the defaults if the bitbang->txrx_bufs
+ * routine isn't initialized.
*
* This routine registers the spi_master, which will process requests in a
* dedicated task, keeping IRQs unblocked most of the time. To stop
if (!bitbang->master || !bitbang->chipselect)
return -EINVAL;
- INIT_WORK(&bitbang->work, bitbang_work, bitbang);
+ INIT_WORK(&bitbang->work, bitbang_work);
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) {
/* this task is the only thing to touch the SPI bits */
bitbang->busy = 0;
bitbang->workqueue = create_singlethread_workqueue(
- bitbang->master->cdev.dev->bus_id);
+ dev_name(bitbang->master->dev.parent));
if (bitbang->workqueue == NULL) {
status = -EBUSY;
goto err1;
*/
int spi_bitbang_stop(struct spi_bitbang *bitbang)
{
- unsigned limit = 500;
-
- spin_lock_irq(&bitbang->lock);
- bitbang->shutdown = 0;
- while (!list_empty(&bitbang->queue) && limit--) {
- spin_unlock_irq(&bitbang->lock);
-
- dev_dbg(bitbang->master->cdev.dev, "wait for queue\n");
- msleep(10);
+ spi_unregister_master(bitbang->master);
- spin_lock_irq(&bitbang->lock);
- }
- spin_unlock_irq(&bitbang->lock);
- if (!list_empty(&bitbang->queue)) {
- dev_err(bitbang->master->cdev.dev, "queue didn't empty\n");
- return -EBUSY;
- }
+ WARN_ON(!list_empty(&bitbang->queue));
destroy_workqueue(bitbang->workqueue);
- spi_unregister_master(bitbang->master);
-
return 0;
}
EXPORT_SYMBOL_GPL(spi_bitbang_stop);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff