diff options
Diffstat (limited to 'include/linux/spi/spi.h')
| -rw-r--r-- | include/linux/spi/spi.h | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 176fce9cc6b1..f9e30a5b3543 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 * |