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-rw-r--r--include/linux/spi/spi.h171
1 files changed, 91 insertions, 80 deletions
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 32c94eae8926..7f8b478fdeb3 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -6,18 +6,19 @@
#ifndef __LINUX_SPI_H
#define __LINUX_SPI_H
+#include <linux/acpi.h>
#include <linux/bits.h>
+#include <linux/completion.h>
#include <linux/device.h>
-#include <linux/mod_devicetable.h>
-#include <linux/slab.h>
+#include <linux/gpio/consumer.h>
#include <linux/kthread.h>
-#include <linux/completion.h>
+#include <linux/mod_devicetable.h>
+#include <linux/overflow.h>
#include <linux/scatterlist.h>
-#include <linux/gpio/consumer.h>
+#include <linux/slab.h>
+#include <linux/u64_stats_sync.h>
#include <uapi/linux/spi/spi.h>
-#include <linux/acpi.h>
-#include <linux/u64_stats_sync.h>
struct dma_chan;
struct software_node;
@@ -36,7 +37,7 @@ extern struct bus_type spi_bus_type;
/**
* 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
@@ -55,7 +56,7 @@ extern struct bus_type spi_bus_type;
* @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
@@ -156,7 +157,7 @@ extern void spi_transfer_cs_change_delay_exec(struct spi_message *msg,
* 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
@@ -212,7 +213,7 @@ struct spi_device {
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;
@@ -223,7 +224,7 @@ struct spi_device {
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
@@ -299,11 +300,11 @@ static inline void spi_set_csgpiod(struct spi_device *spi, u8 idx, struct gpio_d
/**
* 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
@@ -415,7 +416,7 @@ extern struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 ch
* @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
@@ -473,7 +474,7 @@ extern struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 ch
* @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
@@ -500,7 +501,7 @@ extern struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 ch
* 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.
@@ -522,15 +523,17 @@ struct spi_controller {
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;
@@ -562,8 +565,7 @@ struct spi_controller {
#define SPI_CONTROLLER_NO_TX BIT(2) /* Can't do buffer write */
#define SPI_CONTROLLER_MUST_RX BIT(3) /* Requires rx */
#define SPI_CONTROLLER_MUST_TX BIT(4) /* Requires tx */
-
-#define SPI_MASTER_GPIO_SS BIT(5) /* GPIO CS must select slave */
+#define SPI_CONTROLLER_GPIO_SS BIT(5) /* GPIO CS must select slave */
/* Flag indicating if the allocation of this struct is devres-managed */
bool devm_allocated;
@@ -576,8 +578,8 @@ struct spi_controller {
};
/*
- * 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);
@@ -595,7 +597,8 @@ struct spi_controller {
/* 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
@@ -613,18 +616,19 @@ struct spi_controller {
*/
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
@@ -705,7 +709,7 @@ struct spi_controller {
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;
@@ -789,7 +793,7 @@ void spi_take_timestamp_post(struct spi_controller *ctlr,
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);
@@ -878,13 +882,13 @@ typedef void (*spi_res_release_t)(struct spi_controller *ctlr,
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;
@@ -902,7 +906,7 @@ struct spi_res {
*
* 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.)
*
@@ -913,8 +917,8 @@ struct spi_res {
/**
* 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
@@ -937,7 +941,7 @@ struct spi_res {
* @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
@@ -966,16 +970,16 @@ struct spi_res {
* 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;
@@ -1009,7 +1013,7 @@ struct spi_res {
* 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
@@ -1023,10 +1027,11 @@ struct spi_res {
* 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;
@@ -1046,9 +1051,9 @@ struct spi_transfer {
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;
@@ -1069,7 +1074,7 @@ struct spi_transfer {
* 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
@@ -1079,8 +1084,10 @@ struct spi_transfer {
* @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
+ * @t: for use with spi_message_alloc() when message and transfers have
+ * been allocated together
*
* A @spi_message is used to execute an atomic sequence of data transfers,
* each represented by a struct spi_transfer. The sequence is "atomic"
@@ -1106,7 +1113,8 @@ struct spi_message {
/* 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.
@@ -1124,15 +1132,19 @@ struct spi_message {
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;
+
+ /* For embedding transfers into the memory of the message */
+ struct spi_transfer t[];
};
static inline void spi_message_init_no_memset(struct spi_message *m)
@@ -1168,7 +1180,7 @@ spi_transfer_delay_exec(struct spi_transfer *t)
/**
* 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
@@ -1185,24 +1197,21 @@ struct spi_transfer *xfers, unsigned int num_xfers)
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;
- m = kzalloc(sizeof(struct spi_message)
- + ntrans * sizeof(struct spi_transfer),
- flags);
+ m = kzalloc(struct_size(m, t, ntrans), flags);
if (m) {
unsigned i;
- struct spi_transfer *t = (struct spi_transfer *)(m + 1);
spi_message_init_no_memset(m);
- for (i = 0; i < ntrans; i++, t++)
- spi_message_add_tail(t, m);
+ for (i = 0; i < ntrans; i++)
+ spi_message_add_tail(&m->t[i], m);
}
return m;
}
@@ -1291,7 +1300,7 @@ typedef void (*spi_replaced_release_t)(struct spi_controller *ctlr,
* 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
@@ -1301,9 +1310,9 @@ typedef void (*spi_replaced_release_t)(struct spi_controller *ctlr,
* @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;
@@ -1329,7 +1338,8 @@ extern int spi_split_transfers_maxwords(struct spi_controller *ctlr,
/*---------------------------------------------------------------------------*/
-/* 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.
*/
@@ -1472,7 +1482,7 @@ static inline ssize_t spi_w8r16(struct spi_device *spi, u8 cmd)
*
* 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)
@@ -1500,7 +1510,7 @@ 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.
*/
@@ -1537,12 +1547,13 @@ static inline ssize_t spi_w8r16be(struct spi_device *spi, u8 cmd)
* 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;
@@ -1554,7 +1565,8 @@ struct spi_board_info {
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;
@@ -1563,12 +1575,14 @@ struct spi_board_info {
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
@@ -1585,7 +1599,8 @@ spi_register_board_info(struct spi_board_info const *info, unsigned n)
{ 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().
@@ -1623,10 +1638,6 @@ spi_transfer_is_last(struct spi_controller *ctlr, struct spi_transfer *xfer)
#define spi_master spi_controller
#define SPI_MASTER_HALF_DUPLEX SPI_CONTROLLER_HALF_DUPLEX
-#define SPI_MASTER_NO_RX SPI_CONTROLLER_NO_RX
-#define SPI_MASTER_NO_TX SPI_CONTROLLER_NO_TX
-#define SPI_MASTER_MUST_RX SPI_CONTROLLER_MUST_RX
-#define SPI_MASTER_MUST_TX SPI_CONTROLLER_MUST_TX
#define spi_master_get_devdata(_ctlr) spi_controller_get_devdata(_ctlr)
#define spi_master_set_devdata(_ctlr, _data) \