* 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.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/kernel.h>
struct spi_transfer *xfer;
bool keep_cs = false;
int ret = 0;
- int ms = 1;
+ unsigned long ms = 1;
spi_set_cs(msg->spi, true);
EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
/**
- * spi_pump_messages - kthread work function which processes spi message queue
- * @work: pointer to kthread work struct contained in the master struct
+ * __spi_pump_messages - function which processes spi message queue
+ * @master: master to process queue for
+ * @in_kthread: true if we are in the context of the message pump thread
*
* This function checks if there is any spi message in the queue that
* needs processing and if so call out to the driver to initialize hardware
* and transfer each message.
*
+ * Note that it is called both from the kthread itself and also from
+ * inside spi_sync(); the queue extraction handling at the top of the
+ * function should deal with this safely.
*/
-static void spi_pump_messages(struct kthread_work *work)
+static void __spi_pump_messages(struct spi_master *master, bool in_kthread)
{
- struct spi_master *master =
- container_of(work, struct spi_master, pump_messages);
unsigned long flags;
bool was_busy = false;
int ret;
- /* Lock queue and check for queue work */
+ /* Lock queue */
spin_lock_irqsave(&master->queue_lock, flags);
+
+ /* Make sure we are not already running a message */
+ if (master->cur_msg) {
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+ return;
+ }
+
+ /* If another context is idling the device then defer */
+ if (master->idling) {
+ queue_kthread_work(&master->kworker, &master->pump_messages);
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+ return;
+ }
+
+ /* Check if the queue is idle */
if (list_empty(&master->queue) || !master->running) {
if (!master->busy) {
spin_unlock_irqrestore(&master->queue_lock, flags);
return;
}
+
+ /* Only do teardown in the thread */
+ if (!in_kthread) {
+ queue_kthread_work(&master->kworker,
+ &master->pump_messages);
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+ return;
+ }
+
master->busy = false;
+ master->idling = true;
spin_unlock_irqrestore(&master->queue_lock, flags);
+
kfree(master->dummy_rx);
master->dummy_rx = NULL;
kfree(master->dummy_tx);
pm_runtime_put_autosuspend(master->dev.parent);
}
trace_spi_master_idle(master);
- return;
- }
- /* Make sure we are not already running a message */
- if (master->cur_msg) {
+ spin_lock_irqsave(&master->queue_lock, flags);
+ master->idling = false;
spin_unlock_irqrestore(&master->queue_lock, flags);
return;
}
+
/* Extract head of queue */
master->cur_msg =
list_first_entry(&master->queue, struct spi_message, queue);
}
}
+/**
+ * spi_pump_messages - kthread work function which processes spi message queue
+ * @work: pointer to kthread work struct contained in the master struct
+ */
+static void spi_pump_messages(struct kthread_work *work)
+{
+ struct spi_master *master =
+ container_of(work, struct spi_master, pump_messages);
+
+ __spi_pump_messages(master, true);
+}
+
static int spi_init_queue(struct spi_master *master)
{
struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
- INIT_LIST_HEAD(&master->queue);
- spin_lock_init(&master->queue_lock);
-
master->running = false;
master->busy = false;
dev_name(&master->dev));
if (IS_ERR(master->kworker_task)) {
dev_err(&master->dev, "failed to create message pump task\n");
- return -ENOMEM;
+ return PTR_ERR(master->kworker_task);
}
init_kthread_work(&master->pump_messages, spi_pump_messages);
return 0;
}
-/**
- * spi_queued_transfer - transfer function for queued transfers
- * @spi: spi device which is requesting transfer
- * @msg: spi message which is to handled is queued to driver queue
- */
-static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
+static int __spi_queued_transfer(struct spi_device *spi,
+ struct spi_message *msg,
+ bool need_pump)
{
struct spi_master *master = spi->master;
unsigned long flags;
msg->status = -EINPROGRESS;
list_add_tail(&msg->queue, &master->queue);
- if (!master->busy)
+ if (!master->busy && need_pump)
queue_kthread_work(&master->kworker, &master->pump_messages);
spin_unlock_irqrestore(&master->queue_lock, flags);
return 0;
}
+/**
+ * spi_queued_transfer - transfer function for queued transfers
+ * @spi: spi device which is requesting transfer
+ * @msg: spi message which is to handled is queued to driver queue
+ */
+static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
+{
+ return __spi_queued_transfer(spi, msg, true);
+}
+
static int spi_master_initialize_queue(struct spi_master *master)
{
int ret;
/*-------------------------------------------------------------------------*/
#if defined(CONFIG_OF)
+static struct spi_device *
+of_register_spi_device(struct spi_master *master, struct device_node *nc)
+{
+ struct spi_device *spi;
+ int rc;
+ u32 value;
+
+ /* Alloc an spi_device */
+ spi = spi_alloc_device(master);
+ if (!spi) {
+ dev_err(&master->dev, "spi_device alloc error for %s\n",
+ nc->full_name);
+ rc = -ENOMEM;
+ goto err_out;
+ }
+
+ /* Select device driver */
+ rc = of_modalias_node(nc, spi->modalias,
+ sizeof(spi->modalias));
+ if (rc < 0) {
+ dev_err(&master->dev, "cannot find modalias for %s\n",
+ nc->full_name);
+ goto err_out;
+ }
+
+ /* Device address */
+ rc = of_property_read_u32(nc, "reg", &value);
+ if (rc) {
+ dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
+ nc->full_name, rc);
+ goto err_out;
+ }
+ spi->chip_select = value;
+
+ /* Mode (clock phase/polarity/etc.) */
+ if (of_find_property(nc, "spi-cpha", NULL))
+ spi->mode |= SPI_CPHA;
+ if (of_find_property(nc, "spi-cpol", NULL))
+ spi->mode |= SPI_CPOL;
+ if (of_find_property(nc, "spi-cs-high", NULL))
+ spi->mode |= SPI_CS_HIGH;
+ if (of_find_property(nc, "spi-3wire", NULL))
+ spi->mode |= SPI_3WIRE;
+ if (of_find_property(nc, "spi-lsb-first", NULL))
+ spi->mode |= SPI_LSB_FIRST;
+
+ /* Device DUAL/QUAD mode */
+ if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
+ switch (value) {
+ case 1:
+ break;
+ case 2:
+ spi->mode |= SPI_TX_DUAL;
+ break;
+ case 4:
+ spi->mode |= SPI_TX_QUAD;
+ break;
+ default:
+ dev_warn(&master->dev,
+ "spi-tx-bus-width %d not supported\n",
+ value);
+ break;
+ }
+ }
+
+ if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
+ switch (value) {
+ case 1:
+ break;
+ case 2:
+ spi->mode |= SPI_RX_DUAL;
+ break;
+ case 4:
+ spi->mode |= SPI_RX_QUAD;
+ break;
+ default:
+ dev_warn(&master->dev,
+ "spi-rx-bus-width %d not supported\n",
+ value);
+ break;
+ }
+ }
+
+ /* Device speed */
+ rc = of_property_read_u32(nc, "spi-max-frequency", &value);
+ if (rc) {
+ dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
+ nc->full_name, rc);
+ goto err_out;
+ }
+ spi->max_speed_hz = value;
+
+ /* IRQ */
+ spi->irq = irq_of_parse_and_map(nc, 0);
+
+ /* Store a pointer to the node in the device structure */
+ of_node_get(nc);
+ spi->dev.of_node = nc;
+
+ /* Register the new device */
+ request_module("%s%s", SPI_MODULE_PREFIX, spi->modalias);
+ rc = spi_add_device(spi);
+ if (rc) {
+ dev_err(&master->dev, "spi_device register error %s\n",
+ nc->full_name);
+ goto err_out;
+ }
+
+ return spi;
+
+err_out:
+ spi_dev_put(spi);
+ return ERR_PTR(rc);
+}
+
/**
* of_register_spi_devices() - Register child devices onto the SPI bus
* @master: Pointer to spi_master device
{
struct spi_device *spi;
struct device_node *nc;
- int rc;
- u32 value;
if (!master->dev.of_node)
return;
for_each_available_child_of_node(master->dev.of_node, nc) {
- /* Alloc an spi_device */
- spi = spi_alloc_device(master);
- if (!spi) {
- dev_err(&master->dev, "spi_device alloc error for %s\n",
- nc->full_name);
- spi_dev_put(spi);
- continue;
- }
-
- /* Select device driver */
- if (of_modalias_node(nc, spi->modalias,
- sizeof(spi->modalias)) < 0) {
- dev_err(&master->dev, "cannot find modalias for %s\n",
- nc->full_name);
- spi_dev_put(spi);
- continue;
- }
-
- /* Device address */
- rc = of_property_read_u32(nc, "reg", &value);
- if (rc) {
- dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
- nc->full_name, rc);
- spi_dev_put(spi);
- continue;
- }
- spi->chip_select = value;
-
- /* Mode (clock phase/polarity/etc.) */
- if (of_find_property(nc, "spi-cpha", NULL))
- spi->mode |= SPI_CPHA;
- if (of_find_property(nc, "spi-cpol", NULL))
- spi->mode |= SPI_CPOL;
- if (of_find_property(nc, "spi-cs-high", NULL))
- spi->mode |= SPI_CS_HIGH;
- if (of_find_property(nc, "spi-3wire", NULL))
- spi->mode |= SPI_3WIRE;
- if (of_find_property(nc, "spi-lsb-first", NULL))
- spi->mode |= SPI_LSB_FIRST;
-
- /* Device DUAL/QUAD mode */
- if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
- switch (value) {
- case 1:
- break;
- case 2:
- spi->mode |= SPI_TX_DUAL;
- break;
- case 4:
- spi->mode |= SPI_TX_QUAD;
- break;
- default:
- dev_warn(&master->dev,
- "spi-tx-bus-width %d not supported\n",
- value);
- break;
- }
- }
-
- if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
- switch (value) {
- case 1:
- break;
- case 2:
- spi->mode |= SPI_RX_DUAL;
- break;
- case 4:
- spi->mode |= SPI_RX_QUAD;
- break;
- default:
- dev_warn(&master->dev,
- "spi-rx-bus-width %d not supported\n",
- value);
- break;
- }
- }
-
- /* Device speed */
- rc = of_property_read_u32(nc, "spi-max-frequency", &value);
- if (rc) {
- dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
- nc->full_name, rc);
- spi_dev_put(spi);
- continue;
- }
- spi->max_speed_hz = value;
-
- /* IRQ */
- spi->irq = irq_of_parse_and_map(nc, 0);
-
- /* Store a pointer to the node in the device structure */
- of_node_get(nc);
- spi->dev.of_node = nc;
-
- /* Register the new device */
- request_module("%s%s", SPI_MODULE_PREFIX, spi->modalias);
- rc = spi_add_device(spi);
- if (rc) {
- dev_err(&master->dev, "spi_device register error %s\n",
+ spi = of_register_spi_device(master, nc);
+ if (IS_ERR(spi))
+ dev_warn(&master->dev, "Failed to create SPI device for %s\n",
nc->full_name);
- spi_dev_put(spi);
- }
-
}
}
#else
dynamic = 1;
}
+ INIT_LIST_HEAD(&master->queue);
+ spin_lock_init(&master->queue_lock);
spin_lock_init(&master->bus_lock_spinlock);
mutex_init(&master->bus_lock_mutex);
master->bus_lock_flag = 0;
DECLARE_COMPLETION_ONSTACK(done);
int status;
struct spi_master *master = spi->master;
+ unsigned long flags;
+
+ status = __spi_validate(spi, message);
+ if (status != 0)
+ return status;
message->complete = spi_complete;
message->context = &done;
+ message->spi = spi;
if (!bus_locked)
mutex_lock(&master->bus_lock_mutex);
- status = spi_async_locked(spi, message);
+ /* If we're not using the legacy transfer method then we will
+ * try to transfer in the calling context so special case.
+ * This code would be less tricky if we could remove the
+ * support for driver implemented message queues.
+ */
+ if (master->transfer == spi_queued_transfer) {
+ spin_lock_irqsave(&master->bus_lock_spinlock, flags);
+
+ trace_spi_message_submit(message);
+
+ status = __spi_queued_transfer(spi, message, false);
+
+ spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
+ } else {
+ status = spi_async_locked(spi, message);
+ }
if (!bus_locked)
mutex_unlock(&master->bus_lock_mutex);
if (status == 0) {
+ /* Push out the messages in the calling context if we
+ * can.
+ */
+ if (master->transfer == spi_queued_transfer)
+ __spi_pump_messages(master, false);
+
wait_for_completion(&done);
status = message->status;
}
/*-------------------------------------------------------------------------*/
+#if IS_ENABLED(CONFIG_OF_DYNAMIC)
+static int __spi_of_device_match(struct device *dev, void *data)
+{
+ return dev->of_node == data;
+}
+
+/* must call put_device() when done with returned spi_device device */
+static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
+{
+ struct device *dev = bus_find_device(&spi_bus_type, NULL, node,
+ __spi_of_device_match);
+ return dev ? to_spi_device(dev) : NULL;
+}
+
+static int __spi_of_master_match(struct device *dev, const void *data)
+{
+ return dev->of_node == data;
+}
+
+/* the spi masters are not using spi_bus, so we find it with another way */
+static struct spi_master *of_find_spi_master_by_node(struct device_node *node)
+{
+ struct device *dev;
+
+ dev = class_find_device(&spi_master_class, NULL, node,
+ __spi_of_master_match);
+ if (!dev)
+ return NULL;
+
+ /* reference got in class_find_device */
+ return container_of(dev, struct spi_master, dev);
+}
+
+static int of_spi_notify(struct notifier_block *nb, unsigned long action,
+ void *arg)
+{
+ struct of_reconfig_data *rd = arg;
+ struct spi_master *master;
+ struct spi_device *spi;
+
+ switch (of_reconfig_get_state_change(action, arg)) {
+ case OF_RECONFIG_CHANGE_ADD:
+ master = of_find_spi_master_by_node(rd->dn->parent);
+ if (master == NULL)
+ return NOTIFY_OK; /* not for us */
+
+ spi = of_register_spi_device(master, rd->dn);
+ put_device(&master->dev);
+
+ if (IS_ERR(spi)) {
+ pr_err("%s: failed to create for '%s'\n",
+ __func__, rd->dn->full_name);
+ return notifier_from_errno(PTR_ERR(spi));
+ }
+ break;
+
+ case OF_RECONFIG_CHANGE_REMOVE:
+ /* find our device by node */
+ spi = of_find_spi_device_by_node(rd->dn);
+ if (spi == NULL)
+ return NOTIFY_OK; /* no? not meant for us */
+
+ /* unregister takes one ref away */
+ spi_unregister_device(spi);
+
+ /* and put the reference of the find */
+ put_device(&spi->dev);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block spi_of_notifier = {
+ .notifier_call = of_spi_notify,
+};
+#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
+extern struct notifier_block spi_of_notifier;
+#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
+
static int __init spi_init(void)
{
int status;
status = class_register(&spi_master_class);
if (status < 0)
goto err2;
+
+ if (IS_ENABLED(CONFIG_OF_DYNAMIC))
+ WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
+
return 0;
err2:
projects / cascardo / linux.git / blobdiff