* @spi: spi_device to register
*
* Companion function to spi_alloc_device. Devices allocated with
- * spi_alloc_device can be added onto the spi bus with this function.
+ * spi_alloc_device can be added onto the SPI bus with this function.
*
* Return: 0 on success; negative errno on failure
*/
* spi_res_alloc - allocate a spi resource that is life-cycle managed
* during the processing of a spi_message while using
* spi_transfer_one
- * @spi: the spi device for which we allocate memory
+ * @spi: the SPI device for which we allocate memory
* @release: the release code to execute for this resource
* @size: size to alloc and return
* @gfp: GFP allocation flags
}
/**
- * spi_res_free - free an spi resource
+ * spi_res_free - free an SPI resource
* @res: pointer to the custom data of a resource
*/
static void spi_res_free(void *res)
/**
* spi_res_add - add a spi_res to the spi_message
- * @message: the spi message
+ * @message: the SPI message
* @res: the spi_resource
*/
static void spi_res_add(struct spi_message *message, void *res)
}
/**
- * spi_res_release - release all spi resources for this message
+ * spi_res_release - release all SPI resources for this message
* @ctlr: the @spi_controller
* @message: the @spi_message
*/
return -EINVAL;
/*
* If there is unknown effective speed, approximate it
- * by underestimating with half of the requested hz.
+ * by underestimating with half of the requested Hz.
*/
hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2;
if (!hz)
}
/**
- * __spi_pump_messages - function which processes spi message queue
+ * __spi_pump_messages - function which processes SPI message queue
* @ctlr: controller 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
+ * 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.
*
unsigned long flags;
int ret;
- /* Take the IO mutex */
+ /* Take the I/O mutex */
mutex_lock(&ctlr->io_mutex);
/* Lock queue */
/**
* 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
+ * @spi: SPI device which is requesting transfer
+ * @msg: SPI message which is to handled is queued to driver queue
*
* Return: zero on success, else a negative error code.
*/
* acpi_spi_count_resources - Count the number of SpiSerialBus resources
* @adev: ACPI device
*
- * Returns the number of SpiSerialBus resources in the ACPI-device's
+ * Return: the number of SpiSerialBus resources in the ACPI-device's
* resource-list; or a negative error code.
*/
int acpi_spi_count_resources(struct acpi_device *adev)
* @adev: ACPI Device for the spi device
* @index: Index of the spi resource inside the ACPI Node
*
- * This should be used to allocate a new spi device from and ACPI Node.
- * The caller is responsible for calling spi_add_device to register the spi device.
+ * This should be used to allocate a new SPI device from and ACPI Device node.
+ * The caller is responsible for calling spi_add_device to register the SPI device.
*
- * If ctlr is set to NULL, the Controller for the spi device will be looked up
+ * If ctlr is set to NULL, the Controller for the SPI device will be looked up
* using the resource.
* If index is set to -1, index is not used.
* Note: If index is -1, ctlr must be set.
if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
mutex_unlock(&ctlr->add_lock);
- /* Release the last reference on the controller if its driver
+ /*
+ * Release the last reference on the controller if its driver
* has not yet been converted to devm_spi_alloc_master/slave().
*/
if (!ctlr->devm_allocated)
/* All the others need rx_buf/tx_buf also set */
for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
- /* Update rx_buf, tx_buf and dma */
+ /* Update rx_buf, tx_buf and DMA */
if (xfers[i].rx_buf)
xfers[i].rx_buf += offset;
if (xfers[i].rx_dma)
/**
- * spi_split_transfers_maxwords - split spi transfers into multiple transfers
+ * spi_split_transfers_maxwords - split SPI transfers into multiple transfers
* when an individual transfer exceeds a
* certain number of SPI words
* @ctlr: the @spi_controller for this transfer
/*-------------------------------------------------------------------------*/
-/* Core methods for SPI controller protocol drivers. Some of the
+/*
+ * Core methods for SPI controller protocol drivers. Some of the
* other core methods are currently defined as inline functions.
*/
* changes those settings, and must be called from a context that can sleep.
* Except for SPI_CS_HIGH, which takes effect immediately, the changes take
* effect the next time the device is selected and data is transferred to
- * or from it. When this function returns, the spi device is deselected.
+ * or from it. When this function returns, the SPI device is deselected.
*
* Note that this call will fail if the protocol driver specifies an option
* that the underlying controller or its driver does not support. For
* spi_async - asynchronous SPI transfer
* @spi: device with which data will be exchanged
* @message: describes the data transfers, including completion callback
- * Context: any (irqs may be blocked, etc)
+ * Context: any (IRQs may be blocked, etc)
*
* This call may be used in_irq and other contexts which can't sleep,
* as well as from task contexts which can sleep.
* spi_async_locked - version of spi_async with exclusive bus usage
* @spi: device with which data will be exchanged
* @message: describes the data transfers, including completion callback
- * Context: any (irqs may be blocked, etc)
+ * Context: any (IRQs may be blocked, etc)
*
* This call may be used in_irq and other contexts which can't sleep,
* as well as from task contexts which can sleep.
/**
* spi_write_then_read - SPI synchronous write followed by read
* @spi: device with which data will be exchanged
- * @txbuf: data to be written (need not be dma-safe)
+ * @txbuf: data to be written (need not be DMA-safe)
* @n_tx: size of txbuf, in bytes
- * @rxbuf: buffer into which data will be read (need not be dma-safe)
+ * @rxbuf: buffer into which data will be read (need not be DMA-safe)
* @n_rx: size of rxbuf, in bytes
* Context: can sleep
*
*
* Parameters to this routine are always copied using a small buffer.
* Performance-sensitive or bulk transfer code should instead use
- * spi_{async,sync}() calls with dma-safe buffers.
+ * spi_{async,sync}() calls with DMA-safe buffers.
*
* Return: zero on success, else a negative error code.
*/
x[0].tx_buf = local_buf;
x[1].rx_buf = local_buf + n_tx;
- /* Do the i/o */
+ /* Do the I/O */
status = spi_sync(spi, &message);
if (status == 0)
memcpy(rxbuf, x[1].rx_buf, n_rx);
/**
* struct spi_statistics - statistics for spi transfers
- * @syncp: seqcount to protect members in this struct for per-cpu udate
+ * @syncp: seqcount to protect members in this struct for per-cpu update
* on 32-bit systems
*
* @messages: number of spi-messages handled
* @bytes_rx: number of bytes received from device
*
* @transfer_bytes_histo:
- * transfer bytes histogramm
+ * transfer bytes histogram
*
* @transfers_split_maxsize:
* number of transfers that have been split because of
* the device will bind to the named driver and only the named driver.
* Do not set directly, because core frees it; use driver_set_override() to
* set or clear it.
- * @cs_gpiod: gpio descriptor of the chipselect line (optional, NULL when
+ * @cs_gpiod: GPIO descriptor of the chipselect line (optional, NULL when
* not using a GPIO line)
* @word_delay: delay to be inserted between consecutive
* words of a transfer
void *controller_data;
char modalias[SPI_NAME_SIZE];
const char *driver_override;
- struct gpio_desc *cs_gpiod; /* Chip select gpio desc */
+ struct gpio_desc *cs_gpiod; /* Chip select GPIO descriptor */
struct spi_delay word_delay; /* Inter-word delay */
/* CS delays */
struct spi_delay cs_setup;
struct spi_statistics __percpu *pcpu_statistics;
/*
- * likely need more hooks for more protocol options affecting how
+ * Likely need more hooks for more protocol options affecting how
* the controller talks to each chip, like:
* - memory packing (12 bit samples into low bits, others zeroed)
* - priority
/**
* struct spi_driver - Host side "protocol" driver
* @id_table: List of SPI devices supported by this driver
- * @probe: Binds this driver to the spi device. Drivers can verify
+ * @probe: Binds this driver to the SPI device. Drivers can verify
* that the device is actually present, and may need to configure
* characteristics (such as bits_per_word) which weren't needed for
* the initial configuration done during system setup.
- * @remove: Unbinds this driver from the spi device
+ * @remove: Unbinds this driver from the SPI device
* @shutdown: Standard shutdown callback used during system state
* transitions such as powerdown/halt and kexec
* @driver: SPI device drivers should initialize the name and owner
* @queued: whether this controller is providing an internal message queue
* @kworker: pointer to thread struct for message pump
* @pump_messages: work struct for scheduling work to the message pump
- * @queue_lock: spinlock to syncronise access to message queue
+ * @queue_lock: spinlock to synchronise access to message queue
* @queue: message queue
* @cur_msg: the currently in-flight message
* @cur_msg_completion: a completion for the current in-flight message
* @unprepare_message: undo any work done by prepare_message().
* @slave_abort: abort the ongoing transfer request on an SPI slave controller
* @target_abort: abort the ongoing transfer request on an SPI target controller
- * @cs_gpiods: Array of GPIO descs to use as chip select lines; one per CS
+ * @cs_gpiods: Array of GPIO descriptors to use as chip select lines; one per CS
* number. Any individual value may be NULL for CS lines that
* are not GPIOs (driven by the SPI controller itself).
* @use_gpio_descriptors: Turns on the code in the SPI core to parse and grab
* If the driver does not set this, the SPI core takes the snapshot as
* close to the driver hand-over as possible.
* @irq_flags: Interrupt enable state during PTP system timestamping
- * @fallback: fallback to pio if dma transfer return failure with
+ * @fallback: fallback to PIO if DMA transfer return failure with
* SPI_TRANS_FAIL_NO_START.
* @queue_empty: signal green light for opportunistically skipping the queue
* for spi_sync transfers.
struct list_head list;
- /* Other than negative (== assign one dynamically), bus_num is fully
- * board-specific. usually that simplifies to being SOC-specific.
- * example: one SOC has three SPI controllers, numbered 0..2,
- * and one board's schematics might show it using SPI-2. software
+ /*
+ * Other than negative (== assign one dynamically), bus_num is fully
+ * board-specific. Usually that simplifies to being SoC-specific.
+ * example: one SoC has three SPI controllers, numbered 0..2,
+ * and one board's schematics might show it using SPI-2. Software
* would normally use bus_num=2 for that controller.
*/
s16 bus_num;
- /* chipselects will be integral to many controllers; some others
+ /*
+ * Chipselects will be integral to many controllers; some others
* might use board-specific GPIOs.
*/
u16 num_chipselect;
};
/*
- * on some hardware transfer / message size may be constrained
- * the limit may depend on device transfer settings
+ * On some hardware transfer / message size may be constrained
+ * the limit may depend on device transfer settings.
*/
size_t (*max_transfer_size)(struct spi_device *spi);
size_t (*max_message_size)(struct spi_device *spi);
/* Flag indicating that the SPI bus is locked for exclusive use */
bool bus_lock_flag;
- /* Setup mode and clock, etc (spi driver may call many times).
+ /*
+ * Setup mode and clock, etc (SPI driver may call many times).
*
* IMPORTANT: this may be called when transfers to another
* device are active. DO NOT UPDATE SHARED REGISTERS in ways
*/
int (*set_cs_timing)(struct spi_device *spi);
- /* Bidirectional bulk transfers
+ /*
+ * Bidirectional bulk transfers
*
* + The transfer() method may not sleep; its main role is
* just to add the message to the queue.
* + For now there's no remove-from-queue operation, or
* any other request management
- * + To a given spi_device, message queueing is pure fifo
+ * + To a given spi_device, message queueing is pure FIFO
*
* + The controller's main job is to process its message queue,
* selecting a chip (for masters), then transferring data
* + If there are multiple spi_device children, the i/o queue
- * arbitration algorithm is unspecified (round robin, fifo,
+ * arbitration algorithm is unspecified (round robin, FIFO,
* priority, reservations, preemption, etc)
*
* + Chipselect stays active during the entire message
const struct spi_controller_mem_ops *mem_ops;
const struct spi_controller_mem_caps *mem_caps;
- /* gpio chip select */
+ /* GPIO chip select */
struct gpio_desc **cs_gpiods;
bool use_gpio_descriptors;
s8 unused_native_cs;
struct spi_transfer *xfer,
size_t progress, bool irqs_off);
-/* The spi driver core manages memory for the spi_controller classdev */
+/* The SPI driver core manages memory for the spi_controller classdev */
extern struct spi_controller *__spi_alloc_controller(struct device *host,
unsigned int size, bool slave);
void *res);
/**
- * struct spi_res - spi resource management structure
+ * struct spi_res - SPI resource management structure
* @entry: list entry
* @release: release code called prior to freeing this resource
* @data: extra data allocated for the specific use-case
*
- * this is based on ideas from devres, but focused on life-cycle
- * management during spi_message processing
+ * This is based on ideas from devres, but focused on life-cycle
+ * management during spi_message processing.
*/
struct spi_res {
struct list_head entry;
*
* The spi_messages themselves consist of a series of read+write transfer
* segments. Those segments always read the same number of bits as they
- * write; but one or the other is easily ignored by passing a null buffer
+ * write; but one or the other is easily ignored by passing a NULL buffer
* pointer. (This is unlike most types of I/O API, because SPI hardware
* is full duplex.)
*
/**
* struct spi_transfer - a read/write buffer pair
- * @tx_buf: data to be written (dma-safe memory), or NULL
- * @rx_buf: data to be read (dma-safe memory), or NULL
+ * @tx_buf: data to be written (DMA-safe memory), or NULL
+ * @rx_buf: data to be read (DMA-safe memory), or NULL
* @tx_dma: DMA address of tx_buf, if @spi_message.is_dma_mapped
* @rx_dma: DMA address of rx_buf, if @spi_message.is_dma_mapped
* @tx_nbits: number of bits used for writing. If 0 the default
* @word_delay: inter word delay to be introduced after each word size
* (set by bits_per_word) transmission.
* @effective_speed_hz: the effective SCK-speed that was used to
- * transfer this transfer. Set to 0 if the spi bus driver does
+ * transfer this transfer. Set to 0 if the SPI bus driver does
* not support it.
* @transfer_list: transfers are sequenced through @spi_message.transfers
* @tx_sg: Scatterlist for transmit, currently not for client use
* transmitting the "pre" word, and the "post" timestamp after receiving
* transmit confirmation from the controller for the "post" word.
* @timestamped: true if the transfer has been timestamped
- * @error: Error status logged by spi controller driver.
+ * @error: Error status logged by SPI controller driver.
*
* SPI transfers always write the same number of bytes as they read.
* Protocol drivers should always provide @rx_buf and/or @tx_buf.
* In some cases, they may also want to provide DMA addresses for
* the data being transferred; that may reduce overhead, when the
- * underlying driver uses dma.
+ * underlying driver uses DMA.
*
- * If the transmit buffer is null, zeroes will be shifted out
- * while filling @rx_buf. If the receive buffer is null, the data
+ * If the transmit buffer is NULL, zeroes will be shifted out
+ * while filling @rx_buf. If the receive buffer is NULL, the data
* shifted in will be discarded. Only "len" bytes shift out (or in).
* It's an error to try to shift out a partial word. (For example, by
* shifting out three bytes with word size of sixteen or twenty bits;
* Some devices need protocol transactions to be built from a series of
* spi_message submissions, where the content of one message is determined
* by the results of previous messages and where the whole transaction
- * ends when the chipselect goes intactive.
+ * ends when the chipselect goes inactive.
*
* When SPI can transfer in 1x,2x or 4x. It can get this transfer information
* from device through @tx_nbits and @rx_nbits. In Bi-direction, these
* and its transfers, ignore them until its completion callback.
*/
struct spi_transfer {
- /* It's ok if tx_buf == rx_buf (right?)
- * for MicroWire, one buffer must be null
- * buffers must work with dma_*map_single() calls, unless
- * spi_message.is_dma_mapped reports a pre-existing mapping
+ /*
+ * It's okay if tx_buf == rx_buf (right?).
+ * For MicroWire, one buffer must be NULL.
+ * Buffers must work with dma_*map_single() calls, unless
+ * spi_message.is_dma_mapped reports a pre-existing mapping.
*/
const void *tx_buf;
void *rx_buf;
unsigned tx_nbits:3;
unsigned rx_nbits:3;
unsigned timestamped:1;
-#define SPI_NBITS_SINGLE 0x01 /* 1bit transfer */
-#define SPI_NBITS_DUAL 0x02 /* 2bits transfer */
-#define SPI_NBITS_QUAD 0x04 /* 4bits transfer */
+#define SPI_NBITS_SINGLE 0x01 /* 1-bit transfer */
+#define SPI_NBITS_DUAL 0x02 /* 2-bit transfer */
+#define SPI_NBITS_QUAD 0x04 /* 4-bit transfer */
u8 bits_per_word;
struct spi_delay delay;
struct spi_delay cs_change_delay;
* struct spi_message - one multi-segment SPI transaction
* @transfers: list of transfer segments in this transaction
* @spi: SPI device to which the transaction is queued
- * @is_dma_mapped: if true, the caller provided both dma and cpu virtual
+ * @is_dma_mapped: if true, the caller provided both DMA and CPU virtual
* addresses for each transfer buffer
* @complete: called to report transaction completions
* @context: the argument to complete() when it's called
* @status: zero for success, else negative errno
* @queue: for use by whichever driver currently owns the message
* @state: for use by whichever driver currently owns the message
- * @resources: for resource management when the spi message is processed
+ * @resources: for resource management when the SPI message is processed
* @prepared: spi_prepare_message was called for the this message
*
* A @spi_message is used to execute an atomic sequence of data transfers,
/* spi_prepare_message() was called for this message */
bool prepared;
- /* REVISIT: we might want a flag affecting the behavior of the
+ /*
+ * REVISIT: we might want a flag affecting the behavior of the
* last transfer ... allowing things like "read 16 bit length L"
* immediately followed by "read L bytes". Basically imposing
* a specific message scheduling algorithm.
unsigned frame_length;
unsigned actual_length;
- /* For optional use by whatever driver currently owns the
+ /*
+ * For optional use by whatever driver currently owns the
* spi_message ... between calls to spi_async and then later
* complete(), that's the spi_controller controller driver.
*/
struct list_head queue;
void *state;
- /* List of spi_res reources when the spi message is processed */
+ /* List of spi_res resources when the SPI message is processed */
struct list_head resources;
};
/**
* spi_message_init_with_transfers - Initialize spi_message and append transfers
* @m: spi_message to be initialized
- * @xfers: An array of spi transfers
+ * @xfers: An array of SPI transfers
* @num_xfers: Number of items in the xfer array
*
* This function initializes the given spi_message and adds each spi_transfer in
spi_message_add_tail(&xfers[i], m);
}
-/* It's fine to embed message and transaction structures in other data
+/*
+ * It's fine to embed message and transaction structures in other data
* structures so long as you don't free them while they're in use.
*/
-
static inline struct spi_message *spi_message_alloc(unsigned ntrans, gfp_t flags)
{
struct spi_message *m;
* replacements that have occurred
* so that they can get reverted
* @release: some extra release code to get executed prior to
- * relasing this structure
+ * releasing this structure
* @extradata: pointer to some extra data if requested or NULL
* @replaced_transfers: transfers that have been replaced and which need
* to get restored
* @inserted_transfers: array of spi_transfers of array-size @inserted,
* that have been replacing replaced_transfers
*
- * note: that @extradata will point to @inserted_transfers[@inserted]
+ * Note: that @extradata will point to @inserted_transfers[@inserted]
* if some extra allocation is requested, so alignment will be the same
- * as for spi_transfers
+ * as for spi_transfers.
*/
struct spi_replaced_transfers {
spi_replaced_release_t release;
/*---------------------------------------------------------------------------*/
-/* All these synchronous SPI transfer routines are utilities layered
+/*
+ * All these synchronous SPI transfer routines are utilities layered
* over the core async transfer primitive. Here, "synchronous" means
* they will sleep uninterruptibly until the async transfer completes.
*/
*
* Callable only from contexts that can sleep.
*
- * Return: the (unsigned) sixteen bit number returned by the device in cpu
+ * Return: the (unsigned) sixteen bit number returned by the device in CPU
* endianness, or else a negative error code.
*/
static inline ssize_t spi_w8r16be(struct spi_device *spi, u8 cmd)
* As a rule, SPI devices can't be probed. Instead, board init code
* provides a table listing the devices which are present, with enough
* information to bind and set up the device's driver. There's basic
- * support for nonstatic configurations too; enough to handle adding
+ * support for non-static configurations too; enough to handle adding
* parport adapters, or microcontrollers acting as USB-to-SPI bridges.
*/
* are active in some dynamic board configuration models.
*/
struct spi_board_info {
- /* The device name and module name are coupled, like platform_bus;
+ /*
+ * The device name and module name are coupled, like platform_bus;
* "modalias" is normally the driver name.
*
* platform_data goes to spi_device.dev.platform_data,
* controller_data goes to spi_device.controller_data,
- * irq is copied too
+ * IRQ is copied too.
*/
char modalias[SPI_NAME_SIZE];
const void *platform_data;
u32 max_speed_hz;
- /* bus_num is board specific and matches the bus_num of some
+ /*
+ * bus_num is board specific and matches the bus_num of some
* spi_controller that will probably be registered later.
*
* chip_select reflects how this chip is wired to that master;
u16 bus_num;
u16 chip_select;
- /* mode becomes spi_device.mode, and is essential for chips
+ /*
+ * mode becomes spi_device.mode, and is essential for chips
* where the default of SPI_CS_HIGH = 0 is wrong.
*/
u32 mode;
- /* ... may need additional spi_device chip config data here.
+ /*
+ * ... may need additional spi_device chip config data here.
* avoid stuff protocol drivers can set; but include stuff
* needed to behave without being bound to a driver:
* - quirks like clock rate mattering when not selected
{ return 0; }
#endif
-/* If you're hotplugging an adapter with devices (parport, usb, etc)
+/*
+ * If you're hotplugging an adapter with devices (parport, USB, etc)
* use spi_new_device() to describe each device. You can also call
* spi_unregister_device() to start making that device vanish, but
* normally that would be handled by spi_unregister_controller().
projects / platform / kernel / linux-starfive.git / commitdiff