From 56ec1978ff07380bbdc0a942c8779ec9fd9e02ee Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Mon, 7 Oct 2013 19:33:53 +0100 Subject: spi: Provide trace points for message processing Provide tracepoints for the lifecycle of a message from submission to completion and for the active time for masters to help with performance analysis of SPI I/O. Signed-off-by: Mark Brown --- drivers/spi/spi.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) (limited to 'drivers/spi/spi.c') diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 9e039c60c068..8bef0c9a7233 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -39,6 +39,9 @@ #include #include +#define CREATE_TRACE_POINTS +#include + static void spidev_release(struct device *dev) { struct spi_device *spi = to_spi_device(dev); @@ -557,6 +560,7 @@ static void spi_pump_messages(struct kthread_work *work) pm_runtime_mark_last_busy(master->dev.parent); pm_runtime_put_autosuspend(master->dev.parent); } + trace_spi_master_idle(master); return; } @@ -585,6 +589,9 @@ static void spi_pump_messages(struct kthread_work *work) } } + if (!was_busy) + trace_spi_master_busy(master); + if (!was_busy && master->prepare_transfer_hardware) { ret = master->prepare_transfer_hardware(master); if (ret) { @@ -597,6 +604,8 @@ static void spi_pump_messages(struct kthread_work *work) } } + trace_spi_message_start(master->cur_msg); + ret = master->transfer_one_message(master, master->cur_msg); if (ret) { dev_err(&master->dev, @@ -689,6 +698,8 @@ void spi_finalize_current_message(struct spi_master *master) mesg->state = NULL; if (mesg->complete) mesg->complete(mesg->context); + + trace_spi_message_done(mesg); } EXPORT_SYMBOL_GPL(spi_finalize_current_message); @@ -1421,6 +1432,10 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message) struct spi_master *master = spi->master; struct spi_transfer *xfer; + message->spi = spi; + + trace_spi_message_submit(message); + if (list_empty(&message->transfers)) return -EINVAL; if (!message->complete) @@ -1520,7 +1535,6 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message) } } - message->spi = spi; message->status = -EINPROGRESS; return master->transfer(spi, message); } -- cgit v1.2.3 From 2841a5fc375e9c573d10b82db30fa8a4cc25301c Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Sat, 5 Oct 2013 00:23:12 +0100 Subject: spi: Provide per-message prepare and unprepare operations Many SPI drivers perform setup and tear down on every message, usually doing things like DMA mapping the message. Provide hooks for them to use to provide such operations. This is of limited value for drivers that implement transfer_one_message() but will be of much greater utility with future factoring out of standard implementations of that function. Signed-off-by: Mark Brown --- drivers/spi/spi.c | 22 ++++++++++++++++++++++ include/linux/spi/spi.h | 11 +++++++++++ 2 files changed, 33 insertions(+) (limited to 'drivers/spi/spi.c') diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 8bef0c9a7233..8a30c6b66a64 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -606,6 +606,18 @@ static void spi_pump_messages(struct kthread_work *work) trace_spi_message_start(master->cur_msg); + if (master->prepare_message) { + ret = master->prepare_message(master, master->cur_msg); + if (ret) { + dev_err(&master->dev, + "failed to prepare message: %d\n", ret); + master->cur_msg->status = ret; + spi_finalize_current_message(master); + return; + } + master->cur_msg_prepared = true; + } + ret = master->transfer_one_message(master, master->cur_msg); if (ret) { dev_err(&master->dev, @@ -687,6 +699,7 @@ void spi_finalize_current_message(struct spi_master *master) { struct spi_message *mesg; unsigned long flags; + int ret; spin_lock_irqsave(&master->queue_lock, flags); mesg = master->cur_msg; @@ -695,6 +708,15 @@ void spi_finalize_current_message(struct spi_master *master) queue_kthread_work(&master->kworker, &master->pump_messages); spin_unlock_irqrestore(&master->queue_lock, flags); + if (master->cur_msg_prepared && master->unprepare_message) { + ret = master->unprepare_message(master, mesg); + if (ret) { + dev_err(&master->dev, + "failed to unprepare message: %d\n", ret); + } + } + master->cur_msg_prepared = false; + mesg->state = NULL; if (mesg->complete) mesg->complete(mesg->context); diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 887116dbce2c..000b50bee6c0 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -257,6 +257,8 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) * @queue_lock: spinlock to syncronise access to message queue * @queue: message queue * @cur_msg: the currently in-flight message + * @cur_msg_prepared: spi_prepare_message was called for 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 @@ -274,6 +276,10 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) * @unprepare_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 + * @prepare_message: set up the controller to transfer a single message, + * for example doing DMA mapping. Called from threaded + * context. + * @unprepare_message: undo any work done by prepare_message(). * @cs_gpios: Array of GPIOs to use as chip select lines; one per CS * number. Any individual value may be -ENOENT for CS lines that * are not GPIOs (driven by the SPI controller itself). @@ -388,11 +394,16 @@ struct spi_master { bool running; bool rt; bool auto_runtime_pm; + bool cur_msg_prepared; 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); + int (*prepare_message)(struct spi_master *master, + struct spi_message *message); + int (*unprepare_message)(struct spi_master *master, + struct spi_message *message); /* gpio chip select */ int *cs_gpios; -- cgit v1.2.3 From b158935f70b9c156903338053216dd0adf7ce31c Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Sat, 5 Oct 2013 11:50:40 +0100 Subject: spi: Provide common spi_message processing loop The loops which SPI controller drivers use to process the list of transfers in a spi_message are typically very similar and have some error prone areas such as the handling of /CS. Help simplify drivers by factoring this code out into the core - if drivers provide a transfer_one() function instead of a transfer_one_message() function the core will handle processing at the message level. /CS can be controlled by either setting cs_gpio or providing a set_cs function. If this is not possible for hardware reasons then both can be omitted and the driver should continue to implement manual /CS handling. This is a first step in refactoring and it is expected that there will be further enhancements, for example factoring out of the mapping of transfers for DMA and the initiation and completion of interrupt driven transfers. Signed-off-by: Mark Brown --- drivers/spi/spi.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/spi/spi.h | 21 ++++++++++- include/trace/events/spi.h | 42 +++++++++++++++++++++ 3 files changed, 153 insertions(+), 2 deletions(-) (limited to 'drivers/spi/spi.c') diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 8a30c6b66a64..85c18d8a86b3 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -526,6 +526,95 @@ int spi_register_board_info(struct spi_board_info const *info, unsigned n) /*-------------------------------------------------------------------------*/ +static void spi_set_cs(struct spi_device *spi, bool enable) +{ + if (spi->mode & SPI_CS_HIGH) + enable = !enable; + + if (spi->cs_gpio >= 0) + gpio_set_value(spi->cs_gpio, !enable); + else if (spi->master->set_cs) + spi->master->set_cs(spi, !enable); +} + +/* + * spi_transfer_one_message - Default implementation of transfer_one_message() + * + * This is a standard implementation of transfer_one_message() for + * drivers which impelment a transfer_one() operation. It provides + * standard handling of delays and chip select management. + */ +static int spi_transfer_one_message(struct spi_master *master, + struct spi_message *msg) +{ + struct spi_transfer *xfer; + bool cur_cs = true; + bool keep_cs = false; + int ret = 0; + + spi_set_cs(msg->spi, true); + + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + trace_spi_transfer_start(msg, xfer); + + INIT_COMPLETION(master->xfer_completion); + + ret = master->transfer_one(master, msg->spi, xfer); + if (ret < 0) { + dev_err(&msg->spi->dev, + "SPI transfer failed: %d\n", ret); + goto out; + } + + if (ret > 0) + wait_for_completion(&master->xfer_completion); + + trace_spi_transfer_stop(msg, xfer); + + if (msg->status != -EINPROGRESS) + goto out; + + if (xfer->delay_usecs) + udelay(xfer->delay_usecs); + + if (xfer->cs_change) { + if (list_is_last(&xfer->transfer_list, + &msg->transfers)) { + keep_cs = true; + } else { + cur_cs = !cur_cs; + spi_set_cs(msg->spi, cur_cs); + } + } + + msg->actual_length += xfer->len; + } + +out: + if (ret != 0 || !keep_cs) + spi_set_cs(msg->spi, false); + + if (msg->status == -EINPROGRESS) + msg->status = ret; + + spi_finalize_current_message(master); + + return ret; +} + +/** + * spi_finalize_current_transfer - report completion of a transfer + * + * Called by SPI drivers using the core transfer_one_message() + * implementation to notify it that the current interrupt driven + * transfer has finised and the next one may be scheduled. + */ +void spi_finalize_current_transfer(struct spi_master *master) +{ + complete(&master->xfer_completion); +} +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 @@ -836,6 +925,8 @@ static int spi_master_initialize_queue(struct spi_master *master) master->queued = true; master->transfer = spi_queued_transfer; + if (!master->transfer_one_message) + master->transfer_one_message = spi_transfer_one_message; /* Initialize and start queue */ ret = spi_init_queue(master); @@ -1242,6 +1333,7 @@ int spi_register_master(struct spi_master *master) spin_lock_init(&master->bus_lock_spinlock); mutex_init(&master->bus_lock_mutex); master->bus_lock_flag = 0; + init_completion(&master->xfer_completion); /* register the device, then userspace will see it. * registration fails if the bus ID is in use. diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 000b50bee6c0..da371ab5ebeb 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -23,6 +23,7 @@ #include #include #include +#include /* * INTERFACES between SPI master-side drivers and SPI infrastructure. @@ -150,8 +151,7 @@ static inline void *spi_get_drvdata(struct spi_device *spi) } struct spi_message; - - +struct spi_transfer; /** * struct spi_driver - Host side "protocol" driver @@ -259,6 +259,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) * @cur_msg: the currently in-flight message * @cur_msg_prepared: spi_prepare_message was called for the currently * in-flight message + * @xfer_completion: used by core tranfer_one_message() * @busy: message pump is busy * @running: message pump is running * @rt: whether this queue is set to run as a realtime task @@ -276,9 +277,15 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) * @unprepare_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 + * @set_cs: assert or deassert chip select, true to assert. May be called + * from interrupt context. * @prepare_message: set up the controller to transfer a single message, * for example doing DMA mapping. Called from threaded * context. + * @transfer_one: transfer a single spi_transfer. When the + * driver is finished with this transfer it must call + * spi_finalize_current_transfer() so the subsystem can issue + * the next transfer * @unprepare_message: undo any work done by prepare_message(). * @cs_gpios: Array of GPIOs to use as chip select lines; one per CS * number. Any individual value may be -ENOENT for CS lines that @@ -395,6 +402,7 @@ struct spi_master { bool rt; bool auto_runtime_pm; bool cur_msg_prepared; + struct completion xfer_completion; int (*prepare_transfer_hardware)(struct spi_master *master); int (*transfer_one_message)(struct spi_master *master, @@ -405,6 +413,14 @@ struct spi_master { int (*unprepare_message)(struct spi_master *master, struct spi_message *message); + /* + * These hooks are for drivers that use a generic implementation + * of transfer_one_message() provied by the core. + */ + void (*set_cs)(struct spi_device *spi, bool enable); + int (*transfer_one)(struct spi_master *master, struct spi_device *spi, + struct spi_transfer *transfer); + /* gpio chip select */ int *cs_gpios; }; @@ -439,6 +455,7 @@ 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); +extern void spi_finalize_current_transfer(struct spi_master *master); /* the spi driver core manages memory for the spi_master classdev */ extern struct spi_master * diff --git a/include/trace/events/spi.h b/include/trace/events/spi.h index 5e77e21f885a..7e02c983bbe2 100644 --- a/include/trace/events/spi.h +++ b/include/trace/events/spi.h @@ -108,6 +108,48 @@ TRACE_EVENT(spi_message_done, (unsigned)__entry->actual, (unsigned)__entry->frame) ); +DECLARE_EVENT_CLASS(spi_transfer, + + TP_PROTO(struct spi_message *msg, struct spi_transfer *xfer), + + TP_ARGS(msg, xfer), + + TP_STRUCT__entry( + __field( int, bus_num ) + __field( int, chip_select ) + __field( struct spi_transfer *, xfer ) + __field( int, len ) + ), + + TP_fast_assign( + __entry->bus_num = msg->spi->master->bus_num; + __entry->chip_select = msg->spi->chip_select; + __entry->xfer = xfer; + __entry->len = xfer->len; + ), + + TP_printk("spi%d.%d %p len=%d", (int)__entry->bus_num, + (int)__entry->chip_select, + (struct spi_message *)__entry->xfer, + (int)__entry->len) +); + +DEFINE_EVENT(spi_transfer, spi_transfer_start, + + TP_PROTO(struct spi_message *msg, struct spi_transfer *xfer), + + TP_ARGS(msg, xfer) + +); + +DEFINE_EVENT(spi_transfer, spi_transfer_stop, + + TP_PROTO(struct spi_message *msg, struct spi_transfer *xfer), + + TP_ARGS(msg, xfer) + +); + #endif /* _TRACE_POWER_H */ /* This part must be outside protection */ -- cgit v1.2.3