staging: nvec: Document public and private API (bdf034d9) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/staging/nvec/nvec.c

+107 −2

Original line number	Diff line number	Diff line
		@@ -71,6 +71,15 @@ static struct mfd_cell nvec_devices[] = {
		},
		};

		/**
		* nvec_register_notifier - Register a notifier with nvec
		* @nvec: A &struct nvec_chip
		* @nb: The notifier block to register
		*
		* Registers a notifier with @nvec. The notifier will be added to an atomic
		* notifier chain that is called for all received messages except those that
		* correspond to a request initiated by nvec_write_sync().
		*/
		int nvec_register_notifier(struct nvec_chip nvec, struct notifier_block nb,
		unsigned int events)
		{
		@@ -78,6 +87,12 @@ int nvec_register_notifier(struct nvec_chip nvec, struct notifier_block nb,
		}
		EXPORT_SYMBOL_GPL(nvec_register_notifier);

		/**
		* nvec_status_notifier - The final notifier
		*
		* Prints a message about control events not handled in the notifier
		* chain.
		*/
		static int nvec_status_notifier(struct notifier_block *nb,
		unsigned long event_type, void *data)
		{
		@@ -93,6 +108,14 @@ static int nvec_status_notifier(struct notifier_block *nb,
		return NOTIFY_OK;
		}

		/**
		* nvec_msg_alloc:
		* @nvec: A &struct nvec_chip
		*
		* Allocate a single &struct nvec_msg object from the message pool of
		* @nvec. The result shall be passed to nvec_msg_free() if no longer
		* used.
		*/
		static struct nvec_msg nvec_msg_alloc(struct nvec_chip nvec)
		{
		int i;
		@@ -109,6 +132,13 @@ static struct nvec_msg nvec_msg_alloc(struct nvec_chip nvec)
		return NULL;
		}

		/**
		* nvec_msg_free:
		* @nvec: A &struct nvec_chip
		* @msg: A message (must be allocated by nvec_msg_alloc() and belong to @nvec)
		*
		* Free the given message
		*/
		static void nvec_msg_free(struct nvec_chip nvec, struct nvec_msg msg)
		{
		if (msg != &nvec->tx_scratch)
		@@ -147,6 +177,13 @@ static size_t nvec_msg_size(struct nvec_msg *msg)
		return 0;
		}

		/**
		* nvec_gpio_set_value - Set the GPIO value
		* @nvec: A &struct nvec_chip
		* @value: The value to write (0 or 1)
		*
		* Like gpio_set_value(), but generating debugging information
		*/
		static void nvec_gpio_set_value(struct nvec_chip *nvec, int value)
		{
		dev_dbg(nvec->dev, "GPIO changed from %u to %u\n",
		@@ -154,6 +191,18 @@ static void nvec_gpio_set_value(struct nvec_chip *nvec, int value)
		gpio_set_value(nvec->gpio, value);
		}

		/**
		* nvec_write_async - Asynchronously write a message to NVEC
		* @nvec: An nvec_chip instance
		* @data: The message data, starting with the request type
		* @size: The size of @data
		*
		* Queue a single message to be transferred to the embedded controller
		* and return immediately.
		*
		* Returns: 0 on success, a negative error code on failure. If a failure
		* occured, the nvec driver may print an error.
		*/
		int nvec_write_async(struct nvec_chip nvec, const unsigned char data,
		short size)
		{
		@@ -178,6 +227,20 @@ int nvec_write_async(struct nvec_chip nvec, const unsigned char data,
		}
		EXPORT_SYMBOL(nvec_write_async);

		/**
		* nvec_write_sync - Write a message to nvec and read the response
		* @nvec: An &struct nvec_chip
		* @data: The data to write
		* @size: The size of @data
		*
		* This is similar to nvec_write_async(), but waits for the
		* request to be answered before returning. This function
		* uses a mutex and can thus not be called from e.g.
		* interrupt handlers.
		*
		* Returns: A pointer to the response message on success,
		* %NULL on failure.
		*/
		struct nvec_msg nvec_write_sync(struct nvec_chip nvec,
		const unsigned char *data, short size)
		{
		@@ -209,7 +272,14 @@ struct nvec_msg nvec_write_sync(struct nvec_chip nvec,
		}
		EXPORT_SYMBOL(nvec_write_sync);

		/* TX worker */
		/**
		* nvec_request_master - Process outgoing messages
		* @work: A &struct work_struct (the tx_worker member of &struct nvec_chip)
		*
		* Processes all outgoing requests by sending the request and awaiting the
		* response, then continuing with the next request. Once a request has a
		* matching response, it will be freed and removed from the list.
		*/
		static void nvec_request_master(struct work_struct *work)
		{
		struct nvec_chip *nvec = container_of(work, struct nvec_chip, tx_work);
		@@ -241,6 +311,14 @@ static void nvec_request_master(struct work_struct *work)
		spin_unlock_irqrestore(&nvec->tx_lock, flags);
		}

		/**
		* parse_msg - Print some information and call the notifiers on an RX message
		* @nvec: A &struct nvec_chip
		* @msg: A message received by @nvec
		*
		* Paarse some pieces of the message and then call the chain of notifiers
		* registered via nvec_register_notifier.
		*/
		static int parse_msg(struct nvec_chip nvec, struct nvec_msg msg)
		{
		if ((msg->data[0] & 1 << 7) == 0 && msg->data[3]) {
		@@ -260,7 +338,13 @@ static int parse_msg(struct nvec_chip nvec, struct nvec_msg msg)
		return 0;
		}

		/* RX worker */
		/**
		* nvec_dispatch - Process messages received from the EC
		* @work: A &struct work_struct (the tx_worker member of &struct nvec_chip)
		*
		* Process messages previously received from the EC and put into the RX
		* queue of the &struct nvec_chip instance associated with @work.
		*/
		static void nvec_dispatch(struct work_struct *work)
		{
		struct nvec_chip *nvec = container_of(work, struct nvec_chip, rx_work);
		@@ -288,6 +372,12 @@ static void nvec_dispatch(struct work_struct *work)
		spin_unlock_irqrestore(&nvec->rx_lock, flags);
		}

		/**
		* nvec_tx_completed - Complete the current transfer
		* @nvec: A &struct nvec_chip
		*
		* This is called when we have received an END_TRANS on a TX transfer.
		*/
		static void nvec_tx_completed(struct nvec_chip *nvec)
		{
		/* We got an END_TRANS, let's skip this, maybe there's an event */
		@@ -300,6 +390,12 @@ static void nvec_tx_completed(struct nvec_chip *nvec)
		}
		}

		/**
		* nvec_rx_completed - Complete the current transfer
		* @nvec: A &struct nvec_chip
		*
		* This is called when we have received an END_TRANS on a RX transfer.
		*/
		static void nvec_rx_completed(struct nvec_chip *nvec)
		{
		if (nvec->rx->pos != nvec_msg_size(nvec->rx))
		@@ -340,6 +436,11 @@ static void nvec_invalid_flags(struct nvec_chip *nvec, unsigned int status,

		/**
		* nvec_tx_set - Set the message to transfer (nvec->tx)
		* @nvec: A &struct nvec_chip
		*
		* Gets the first entry from the tx_data list of @nvec and sets the
		* tx member to it. If the tx_data list is empty, this uses the
		* tx_scratch message to send a no operation message.
		*/
		static void nvec_tx_set(struct nvec_chip *nvec)
		{
		@@ -366,6 +467,10 @@ static void nvec_tx_set(struct nvec_chip *nvec)
		* nvec_interrupt - Interrupt handler
		* @irq: The IRQ
		* @dev: The nvec device
		*
		* Interrupt handler that fills our RX buffers and empties our TX
		* buffers. This uses a finite state machine with ridiculous amounts
		* of error checking, in order to be fairly reliable.
		*/
		static irqreturn_t nvec_interrupt(int irq, void *dev)
		{

drivers/staging/nvec/nvec.h

+84 −2

Original line number	Diff line number	Diff line
		@@ -6,6 +6,7 @@
		* Authors: Pierre-Hugues Husson <phhusson@free.fr>
		* Ilya Petrov <ilya.muromec@gmail.com>
		* Marc Dietrich <marvin24@gmx.de>
		* Julian Andres Klode <jak@jak-linux.org>
		*
		* This file is subject to the terms and conditions of the GNU General Public
		* License. See the file "COPYING" in the main directory of this archive
		@@ -32,13 +33,37 @@
		*/
		#define NVEC_MSG_SIZE 34

		enum {
		/**
		* enum nvec_event_size - The size of an event message
		* @NVEC_2BYTES: The message has one command byte and one data byte
		* @NVEC_3BYTES: The message has one command byte and two data bytes
		* @NVEC_VAR_SIZE: The message has one command byte, one count byte, and as
		* up to as many bytes as the number in the count byte. The
		* maximum is 32
		*
		* Events can be fixed or variable sized. This is useless on other message
		* types, which are always variable sized.
		*/
		enum nvec_event_size {
		NVEC_2BYTES,
		NVEC_3BYTES,
		NVEC_VAR_SIZE,
		};

		enum {
		/**
		* enum nvec_msg_type - The type of a message
		* @NVEC_SYS: A system request/response
		* @NVEC_BAT: A battery request/response
		* @NVEC_KBD: A keyboard request/response
		* @NVEC_PS2: A mouse request/response
		* @NVEC_CNTL: A EC control request/response
		* @NVEC_KB_EVT: An event from the keyboard
		* @NVEC_PS2_EVT: An event from the mouse
		*
		* Events can be fixed or variable sized. This is useless on other message
		* types, which are always variable sized.
		*/
		enum nvec_msg_type {
		NVEC_SYS = 1,
		NVEC_BAT,
		NVEC_KBD = 5,
		@@ -48,6 +73,19 @@ enum {
		NVEC_PS2_EVT,
		};

		/**
		* struct nvec_msg - A buffer for a single message
		* @node: Messages are part of various lists in a &struct nvec_chip
		* @data: The data of the message
		* @size: For TX messages, the number of bytes used in @data
		* @pos: For RX messages, the current position to write to. For TX messages,
		* the position to read from.
		* @used: Used for the message pool to mark a message as free/allocated.
		*
		* This structure is used to hold outgoing and incoming messages. Outgoing
		* messages have a different format than incoming messages, and that is not
		* documented yet.
		*/
		struct nvec_msg {
		struct list_head node;
		unsigned char data[NVEC_MSG_SIZE];
		@@ -56,17 +94,61 @@ struct nvec_msg {
		atomic_t used;
		};

		/**
		* struct nvec_subdev - A subdevice of nvec, such as nvec_kbd
		* @name: The name of the sub device
		* @platform_data: Platform data
		* @id: Identifier of the sub device
		*/
		struct nvec_subdev {
		const char *name;
		void *platform_data;
		int id;
		};

		/**
		* struct nvec_platform_data - platform data for a tegra slave controller
		* @i2c_addr: number of i2c slave adapter the ec is connected to
		* @gpio: gpio number for the ec request line
		*
		* Platform data, to be used in board definitions. For an example, take a
		* look at the paz00 board in arch/arm/mach-tegra/board-paz00.c
		*/
		struct nvec_platform_data {
		int i2c_addr;
		int gpio;
		};

		/**
		* struct nvec_chip - A single connection to an NVIDIA Embedded controller
		* @dev: The device
		* @gpio: The same as for &struct nvec_platform_data
		* @irq: The IRQ of the I2C device
		* @i2c_addr: The address of the I2C slave
		* @base: The base of the memory mapped region of the I2C device
		* @clk: The clock of the I2C device
		* @notifier_list: Notifiers to be called on received messages, see
		* nvec_register_notifier()
		* @rx_data: Received messages that have to be processed
		* @tx_data: Messages waiting to be sent to the controller
		* @nvec_status_notifier: Internal notifier (see nvec_status_notifier())
		* @rx_work: A work structure for the RX worker nvec_dispatch()
		* @tx_work: A work structure for the TX worker nvec_request_master()
		* @wq: The work queue in which @rx_work and @tx_work are executed
		* @rx: The message currently being retrieved or %NULL
		* @msg_pool: A pool of messages for allocation
		* @tx: The message currently being transferred
		* @tx_scratch: Used for building pseudo messages
		* @ec_transfer: A completion that will be completed once a message has been
		* received (see nvec_rx_completed())
		* @tx_lock: Spinlock for modifications on @tx_data
		* @rx_lock: Spinlock for modifications on @rx_data
		* @sync_write_mutex: A mutex for nvec_write_sync()
		* @sync_write: A completion to signal that a synchronous message is complete
		* @sync_write_pending: The first two bytes of the request (type and subtype)
		* @last_sync_msg: The last synchronous message.
		* @state: State of our finite state machine used in nvec_interrupt()
		*/
		struct nvec_chip {
		struct device *dev;
		int gpio;