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Diffstat (limited to 'include/linux/spi/spi.h')
-rw-r--r--include/linux/spi/spi.h53
1 files changed, 52 insertions, 1 deletions
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 176fce9cc6b1..98679b061b63 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -22,6 +22,7 @@
#include <linux/device.h>
#include <linux/mod_devicetable.h>
#include <linux/slab.h>
+#include <linux/kthread.h>
/*
* INTERFACES between SPI master-side drivers and SPI infrastructure.
@@ -235,6 +236,27 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
* the device whose settings are being modified.
* @transfer: adds a message to the controller's transfer queue.
* @cleanup: frees controller-specific state
+ * @queued: whether this master is providing an internal message queue
+ * @kworker: thread struct for message pump
+ * @kworker_task: pointer to task for message pump kworker thread
+ * @pump_messages: work struct for scheduling work to the message pump
+ * @queue_lock: spinlock to syncronise access to message queue
+ * @queue: message queue
+ * @cur_msg: the currently in-flight message
+ * @busy: message pump is busy
+ * @running: message pump is running
+ * @rt: whether this queue is set to run as a realtime task
+ * @prepare_transfer_hardware: a message will soon arrive from the queue
+ * so the subsystem requests the driver to prepare the transfer hardware
+ * by issuing this call
+ * @transfer_one_message: the subsystem calls the driver to transfer a single
+ * message while queuing transfers that arrive in the meantime. When the
+ * driver is finished with this message, it must call
+ * spi_finalize_current_message() so the subsystem can issue the next
+ * transfer
+ * @prepare_transfer_hardware: there are currently no more messages on the
+ * queue so the subsystem notifies the driver that it may relax the
+ * hardware by issuing this call
*
* Each SPI master controller can communicate with one or more @spi_device
* children. These make a small bus, sharing MOSI, MISO and SCK signals
@@ -318,6 +340,28 @@ struct spi_master {
/* called on release() to free memory provided by spi_master */
void (*cleanup)(struct spi_device *spi);
+
+ /*
+ * These hooks are for drivers that want to use the generic
+ * master transfer queueing mechanism. If these are used, the
+ * transfer() function above must NOT be specified by the driver.
+ * Over time we expect SPI drivers to be phased over to this API.
+ */
+ bool queued;
+ struct kthread_worker kworker;
+ struct task_struct *kworker_task;
+ struct kthread_work pump_messages;
+ spinlock_t queue_lock;
+ struct list_head queue;
+ struct spi_message *cur_msg;
+ bool busy;
+ bool running;
+ bool rt;
+
+ int (*prepare_transfer_hardware)(struct spi_master *master);
+ int (*transfer_one_message)(struct spi_master *master,
+ struct spi_message *mesg);
+ int (*unprepare_transfer_hardware)(struct spi_master *master);
};
static inline void *spi_master_get_devdata(struct spi_master *master)
@@ -343,6 +387,13 @@ static inline void spi_master_put(struct spi_master *master)
put_device(&master->dev);
}
+/* PM calls that need to be issued by the driver */
+extern int spi_master_suspend(struct spi_master *master);
+extern int spi_master_resume(struct spi_master *master);
+
+/* Calls the driver make to interact with the message queue */
+extern struct spi_message *spi_get_next_queued_message(struct spi_master *master);
+extern void spi_finalize_current_message(struct spi_master *master);
/* the spi driver core manages memory for the spi_master classdev */
extern struct spi_master *
@@ -549,7 +600,7 @@ static inline struct spi_message *spi_message_alloc(unsigned ntrans, gfp_t flags
+ ntrans * sizeof(struct spi_transfer),
flags);
if (m) {
- int i;
+ unsigned i;
struct spi_transfer *t = (struct spi_transfer *)(m + 1);
INIT_LIST_HEAD(&m->transfers);