@@ -311,10 +311,10 @@ static void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
spin_unlock_irqrestore(&stats->lock, flags);
}
-/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
+/*
+ * modalias support makes "modprobe $MODALIAS" new-style hotplug work,
* and the sysfs version makes coldplug work too.
*/
-
static const struct spi_device_id *spi_match_id(const struct spi_device_id *id, const char *name)
{
while (id->name[0]) {
@@ -492,7 +492,8 @@ EXPORT_SYMBOL_GPL(__spi_register_driver);
/*-------------------------------------------------------------------------*/
-/* SPI devices should normally not be created by SPI device drivers; that
+/*
+ * SPI devices should normally not be created by SPI device drivers; that
* would make them board-specific. Similarly with SPI controller drivers.
* Device registration normally goes into like arch/.../mach.../board-YYY.c
* with other readonly (flashable) information about mainboard devices.
@@ -508,8 +509,8 @@ static LIST_HEAD(spi_controller_list);
/*
* Used to protect add/del operation for board_info list and
- * spi_controller list, and their matching process
- * also used to protect object of type struct idr
+ * spi_controller list, and their matching process also used
+ * to protect object of type struct idr.
*/
static DEFINE_MUTEX(board_lock);
@@ -616,7 +617,8 @@ static int __spi_add_device(struct spi_device *spi)
else if (ctlr->cs_gpios)
spi->cs_gpio = ctlr->cs_gpios[spi->chip_select];
- /* Drivers may modify this initial i/o setup, but will
+ /*
+ * Drivers may modify this initial i/o setup, but will
* normally rely on the device being setup. Devices
* using SPI_CS_HIGH can't coexist well otherwise...
*/
@@ -710,7 +712,8 @@ struct spi_device *spi_new_device(struct spi_controller *ctlr,
struct spi_device *proxy;
int status;
- /* NOTE: caller did any chip->bus_num checks necessary.
+ /*
+ * NOTE: caller did any chip->bus_num checks necessary.
*
* Also, unless we change the return value convention to use
* error-or-pointer (not NULL-or-pointer), troubleshootability
@@ -878,7 +881,6 @@ static void *spi_res_alloc(struct spi_device *spi, spi_res_release_t release,
/**
* spi_res_free - free an spi resource
* @res: pointer to the custom data of a resource
- *
*/
static void spi_res_free(void *res)
{
@@ -973,7 +975,7 @@ static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
gpiod_set_value_cansleep(spi->cs_gpiod, activate);
} else {
/*
- * invert the enable line, as active low is
+ * Invert the enable line, as active low is
* default for SPI.
*/
gpio_set_value_cansleep(spi->cs_gpio, !enable);
@@ -1711,16 +1713,7 @@ static void spi_pump_messages(struct kthread_work *work)
}
/**
- * spi_take_timestamp_pre - helper for drivers to collect the beginning of the
- * TX timestamp for the requested byte from the SPI
- * transfer. The frequency with which this function
- * must be called (once per word, once for the whole
- * transfer, once per batch of words etc) is arbitrary
- * as long as the @tx buffer offset is greater than or
- * equal to the requested byte at the time of the
- * call. The timestamp is only taken once, at the
- * first such call. It is assumed that the driver
- * advances its @tx buffer pointer monotonically.
+ * spi_take_timestamp_pre - helper to collect the beginning of the TX timestamp
* @ctlr: Pointer to the spi_controller structure of the driver
* @xfer: Pointer to the transfer being timestamped
* @progress: How many words (not bytes) have been transferred so far
@@ -1730,6 +1723,14 @@ static void spi_pump_messages(struct kthread_work *work)
* spi_take_timestamp_post or otherwise system will crash.
* WARNING: for fully predictable results, the CPU frequency must
* also be under control (governor).
+ *
+ * This is a helper for drivers to collect the beginning of the TX timestamp
+ * for the requested byte from the SPI transfer. The frequency with which this
+ * function must be called (once per word, once for the whole transfer, once
+ * per batch of words etc) is arbitrary as long as the @tx buffer offset is
+ * greater than or equal to the requested byte at the time of the call. The
+ * timestamp is only taken once, at the first such call. It is assumed that
+ * the driver advances its @tx buffer pointer monotonically.
*/
void spi_take_timestamp_pre(struct spi_controller *ctlr,
struct spi_transfer *xfer,
@@ -1757,16 +1758,16 @@ void spi_take_timestamp_pre(struct spi_controller *ctlr,
EXPORT_SYMBOL_GPL(spi_take_timestamp_pre);
/**
- * spi_take_timestamp_post - helper for drivers to collect the end of the
- * TX timestamp for the requested byte from the SPI
- * transfer. Can be called with an arbitrary
- * frequency: only the first call where @tx exceeds
- * or is equal to the requested word will be
- * timestamped.
+ * spi_take_timestamp_post - helper to collect the end of the TX timestamp
* @ctlr: Pointer to the spi_controller structure of the driver
* @xfer: Pointer to the transfer being timestamped
* @progress: How many words (not bytes) have been transferred so far
* @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.
+ *
+ * This is a helper for drivers to collect the end of the TX timestamp for
+ * the requested byte from the SPI transfer. Can be called with an arbitrary
+ * frequency: only the first call where @tx exceeds or is equal to the
+ * requested word will be timestamped.
*/
void spi_take_timestamp_post(struct spi_controller *ctlr,
struct spi_transfer *xfer,
@@ -1899,10 +1900,12 @@ void spi_finalize_current_message(struct spi_controller *ctlr)
spi_unmap_msg(ctlr, mesg);
- /* In the prepare_messages callback the spi bus has the opportunity to
- * split a transfer to smaller chunks.
- * Release splited transfers here since spi_map_msg is done on the
- * splited transfers.
+ /*
+ * In the prepare_messages callback the SPI bus has the opportunity
+ * to split a transfer to smaller chunks.
+ *
+ * Release the split transfers here since spi_map_msg() is done on
+ * the split transfers.
*/
spi_res_release(ctlr, mesg);
@@ -2944,8 +2947,9 @@ int spi_register_controller(struct spi_controller *ctlr)
if (!ctlr->max_dma_len)
ctlr->max_dma_len = INT_MAX;
- /* register the device, then userspace will see it.
- * registration fails if the bus ID is in use.
+ /*
+ * Register the device, then userspace will see it.
+ * Registration fails if the bus ID is in use.
*/
dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
@@ -3211,16 +3215,18 @@ static struct spi_replaced_transfers *spi_replace_transfers(
/* init the replaced_transfers list */
INIT_LIST_HEAD(&rxfer->replaced_transfers);
- /* assign the list_entry after which we should reinsert
+ /*
+ * Assign the list_entry after which we should reinsert
* the @replaced_transfers - it may be spi_message.messages!
*/
rxfer->replaced_after = xfer_first->transfer_list.prev;
/* remove the requested number of transfers */
for (i = 0; i < remove; i++) {
- /* if the entry after replaced_after it is msg->transfers
+ /*
+ * If the entry after replaced_after it is msg->transfers
* then we have been requested to remove more transfers
- * than are in the list
+ * than are in the list.
*/
if (rxfer->replaced_after->next == &msg->transfers) {
dev_err(&msg->spi->dev,
@@ -3236,15 +3242,17 @@ static struct spi_replaced_transfers *spi_replace_transfers(
return ERR_PTR(-EINVAL);
}
- /* remove the entry after replaced_after from list of
- * transfers and add it to list of replaced_transfers
+ /*
+ * Remove the entry after replaced_after from list of
+ * transfers and add it to list of replaced_transfers.
*/
list_move_tail(rxfer->replaced_after->next,
&rxfer->replaced_transfers);
}
- /* create copy of the given xfer with identical settings
- * based on the first transfer to get removed
+ /*
+ * Create copy of the given xfer with identical settings
+ * based on the first transfer to get removed.
*/
for (i = 0; i < insert; i++) {
/* we need to run in reverse order */
@@ -3292,18 +3300,20 @@ static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
return PTR_ERR(srt);
xfers = srt->inserted_transfers;
- /* now handle each of those newly inserted spi_transfers
- * note that the replacements spi_transfers all are preset
+ /*
+ * Now handle each of those newly inserted spi_transfers.
+ * Note that the replacements spi_transfers all are preset
* to the same values as *xferp, so tx_buf, rx_buf and len
* are all identical (as well as most others)
* so we just have to fix up len and the pointers.
*
- * this also includes support for the depreciated
- * spi_message.is_dma_mapped interface
+ * This also includes support for the depreciated
+ * spi_message.is_dma_mapped interface.
*/
- /* the first transfer just needs the length modified, so we
- * run it outside the loop
+ /*
+ * The first transfer just needs the length modified, so we
+ * run it outside the loop.
*/
xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
@@ -3323,8 +3333,9 @@ static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
xfers[i].len = min(maxsize, xfers[i].len - offset);
}
- /* we set up xferp to the last entry we have inserted,
- * so that we skip those already split transfers
+ /*
+ * We set up xferp to the last entry we have inserted,
+ * so that we skip those already split transfers.
*/
*xferp = &xfers[count - 1];
@@ -3356,11 +3367,12 @@ int spi_split_transfers_maxsize(struct spi_controller *ctlr,
struct spi_transfer *xfer;
int ret;
- /* iterate over the transfer_list,
+ /*
+ * Iterate over the transfer_list,
* but note that xfer is advanced to the last transfer inserted
* to avoid checking sizes again unnecessarily (also xfer does
- * potentiall belong to a different list by the time the
- * replacement has happened
+ * potentially belong to a different list by the time the
+ * replacement has happened).
*/
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
if (xfer->len > maxsize) {
@@ -3421,8 +3433,8 @@ int spi_setup(struct spi_device *spi)
int status;
/*
- * check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO
- * are set at the same time
+ * Check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO
+ * are set at the same time.
*/
if ((hweight_long(spi->mode &
(SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) ||
@@ -3432,20 +3444,21 @@ int spi_setup(struct spi_device *spi)
"setup: can not select any two of dual, quad and no-rx/tx at the same time\n");
return -EINVAL;
}
- /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
- */
+ /* If it is SPI_3WIRE mode, DUAL and QUAD should be forbidden */
if ((spi->mode & SPI_3WIRE) && (spi->mode &
(SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
return -EINVAL;
- /* help drivers fail *cleanly* when they need options
- * that aren't supported with their current controller
+ /*
+ * Help drivers fail *cleanly* when they need options
+ * that aren't supported with their current controller.
* SPI_CS_WORD has a fallback software implementation,
* so it is ignored here.
*/
bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD |
SPI_NO_TX | SPI_NO_RX);
- /* nothing prevents from working with active-high CS in case if it
+ /*
+ * Nothing prevents from working with active-high CS in case if it
* is driven by GPIO.
*/
if (gpio_is_valid(spi->cs_gpio))
@@ -3567,7 +3580,8 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
if (list_empty(&message->transfers))
return -EINVAL;
- /* If an SPI controller does not support toggling the CS line on each
+ /*
+ * If an SPI controller does not support toggling the CS line on each
* transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
* for the CS line, we can emulate the CS-per-word hardware function by
* splitting transfers into one-word transfers and ensuring that
@@ -3597,7 +3611,8 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
}
}
- /* Half-duplex links include original MicroWire, and ones with
+ /*
+ * Half-duplex links include original MicroWire, and ones with
* only one data pin like SPI_3WIRE (switches direction) or where
* either MOSI or MISO is missing. They can also be caused by
* software limitations.
@@ -3616,7 +3631,7 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
}
}
- /**
+ /*
* Set transfer bits_per_word and max speed as spi device default if
* it is not set for this transfer.
* Set transfer tx_nbits and rx_nbits as single transfer default
@@ -3642,7 +3657,7 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
/*
* SPI transfer length should be multiple of SPI word size
- * where SPI word size should be power-of-two multiple
+ * where SPI word size should be power-of-two multiple.
*/
if (xfer->bits_per_word <= 8)
w_size = 1;
@@ -3663,7 +3678,8 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
xfer->tx_nbits = SPI_NBITS_SINGLE;
if (xfer->rx_buf && !xfer->rx_nbits)
xfer->rx_nbits = SPI_NBITS_SINGLE;
- /* check transfer tx/rx_nbits:
+ /*
+ * Check transfer tx/rx_nbits:
* 1. check the value matches one of single, dual and quad
* 2. check tx/rx_nbits match the mode in spi_device
*/
@@ -3842,7 +3858,8 @@ static int spi_async_locked(struct spi_device *spi, struct spi_message *message)
/*-------------------------------------------------------------------------*/
-/* Utility methods for SPI protocol drivers, layered on
+/*
+ * Utility methods for SPI protocol drivers, layered on
* top of the core. Some other utility methods are defined as
* inline functions.
*/
@@ -3870,7 +3887,8 @@ static int __spi_sync(struct spi_device *spi, struct spi_message *message)
SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync);
SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
- /* If we're not using the legacy transfer method then we will
+ /*
+ * 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.
@@ -3888,9 +3906,7 @@ static int __spi_sync(struct spi_device *spi, struct spi_message *message)
}
if (status == 0) {
- /* Push out the messages in the calling context if we
- * can.
- */
+ /* Push out the messages in the calling context if we can */
if (ctlr->transfer == spi_queued_transfer) {
SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
spi_sync_immediate);
@@ -4051,7 +4067,8 @@ int spi_write_then_read(struct spi_device *spi,
struct spi_transfer x[2];
u8 *local_buf;
- /* Use preallocated DMA-safe buffer if we can. We can't avoid
+ /*
+ * Use preallocated DMA-safe buffer if we can. We can't avoid
* copying here, (as a pure convenience thing), but we can
* keep heap costs out of the hot path unless someone else is
* using the pre-allocated buffer or the transfer is too large.
@@ -4287,11 +4304,12 @@ static int __init spi_init(void)
return status;
}
-/* board_info is normally registered in arch_initcall(),
- * but even essential drivers wait till later
+/*
+ * A board_info is normally registered in arch_initcall(),
+ * but even essential drivers wait till later.
*
- * REVISIT only boardinfo really needs static linking. the rest (device and
- * driver registration) _could_ be dynamically linked (modular) ... costs
+ * REVISIT only boardinfo really needs static linking. The rest (device and
+ * driver registration) _could_ be dynamically linked (modular) ... Costs
* include needing to have boardinfo data structures be much more public.
*/
postcore_initcall(spi_init);
/* * Fix multi-line comment style as in this short example. Pay attention * to the capitalization, period and starting line of the text. */ While at it, split the (supposedly short) description of couple of functions to summary (short description) and (long) description. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- v3: no changes drivers/spi/spi.c | 160 ++++++++++++++++++++++++++-------------------- 1 file changed, 89 insertions(+), 71 deletions(-)