/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) ST-Ericsson AB 2010
* Author: Sjur Brendeland
*/
#ifndef CAIF_LAYER_H_
#define CAIF_LAYER_H_
#include <linux/list.h>
struct cflayer;
struct cfpkt;
struct caif_payload_info;
#define CAIF_LAYER_NAME_SZ 16
/**
* caif_assert() - Assert function for CAIF.
* @assert: expression to evaluate.
*
* This function will print a error message and a do WARN_ON if the
* assertion fails. Normally this will do a stack up at the current location.
*/
#define caif_assert(assert) \
do { \
if (!(assert)) { \
pr_err("caif:Assert detected:'%s'\n", #assert); \
WARN_ON(!(assert)); \
} \
} while (0)
/**
* enum caif_ctrlcmd - CAIF Stack Control Signaling sent in layer.ctrlcmd().
*
* @CAIF_CTRLCMD_FLOW_OFF_IND: Flow Control is OFF, transmit function
* should stop sending data
*
* @CAIF_CTRLCMD_FLOW_ON_IND: Flow Control is ON, transmit function
* can start sending data
*
* @CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND: Remote end modem has decided to close
* down channel
*
* @CAIF_CTRLCMD_INIT_RSP: Called initially when the layer below
* has finished initialization
*
* @CAIF_CTRLCMD_DEINIT_RSP: Called when de-initialization is
* complete
*
* @CAIF_CTRLCMD_INIT_FAIL_RSP: Called if initialization fails
*
* @_CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND: CAIF Link layer temporarily cannot
* send more packets.
* @_CAIF_CTRLCMD_PHYIF_FLOW_ON_IND: Called if CAIF Link layer is able
* to send packets again.
* @_CAIF_CTRLCMD_PHYIF_DOWN_IND: Called if CAIF Link layer is going
* down.
*
* These commands are sent upwards in the CAIF stack to the CAIF Client.
* They are used for signaling originating from the modem or CAIF Link Layer.
* These are either responses (*_RSP) or events (*_IND).
*/
enum caif_ctrlcmd {
CAIF_CTRLCMD_FLOW_OFF_IND,
CAIF_CTRLCMD_FLOW_ON_IND,
CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND,
CAIF_CTRLCMD_INIT_RSP,
CAIF_CTRLCMD_DEINIT_RSP,
CAIF_CTRLCMD_INIT_FAIL_RSP,
_CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND,
_CAIF_CTRLCMD_PHYIF_FLOW_ON_IND,
_CAIF_CTRLCMD_PHYIF_DOWN_IND,
};
/**
* enum caif_modemcmd - Modem Control Signaling, sent from CAIF Client
* to the CAIF Link Layer or modem.
*
* @CAIF_MODEMCMD_FLOW_ON_REQ: Flow Control is ON, transmit function
* can start sending data.
*
* @CAIF_MODEMCMD_FLOW_OFF_REQ: Flow Control is OFF, transmit function
* should stop sending data.
*
* @_CAIF_MODEMCMD_PHYIF_USEFULL: Notify physical layer that it is in use
*
* @_CAIF_MODEMCMD_PHYIF_USELESS: Notify physical layer that it is
* no longer in use.
*
* These are requests sent 'downwards' in the stack.
* Flow ON, OFF can be indicated to the modem.
*/
enum caif_modemcmd {
CAIF_MODEMCMD_FLOW_ON_REQ = 0,
CAIF_MODEMCMD_FLOW_OFF_REQ = 1,
_CAIF_MODEMCMD_PHYIF_USEFULL = 3,
_CAIF_MODEMCMD_PHYIF_USELESS = 4
};
/**
* enum caif_direction - CAIF Packet Direction.
* Indicate if a packet is to be sent out or to be received in.
* @CAIF_DIR_IN: Incoming packet received.
* @CAIF_DIR_OUT: Outgoing packet to be transmitted.
*/
enum caif_direction {
CAIF_DIR_IN = 0,
CAIF_DIR_OUT = 1
};
/**
* struct cflayer - CAIF Stack layer.
* Defines the framework for the CAIF Core Stack.
* @up: Pointer up to the layer above.
* @dn: Pointer down to the layer below.
* @node: List node used when layer participate in a list.
* @receive: Packet receive function.
* @transmit: Packet transmit function.
* @ctrlcmd: Used for control signalling upwards in the stack.
* @modemcmd: Used for control signaling downwards in the stack.
* @id: The identity of this layer
* @name: Name of the layer.
*
* This structure defines the layered structure in CAIF.
*
* It defines CAIF layering structure, used by all CAIF Layers and the
* layers interfacing CAIF.
*
* In order to integrate with CAIF an adaptation layer on top of the CAIF stack
* and PHY layer below the CAIF stack
* must be implemented. These layer must follow the design principles below.
*
* Principles for layering of protocol layers:
* - All layers must use this structure. If embedding it, then place this
* structure first in the layer specific structure.
*
* - Each layer should not depend on any others layer's private data.
*
* - In order to send data upwards do
* layer->up->receive(layer->up, packet);
*
* - In order to send data downwards do
* layer->dn->transmit(layer->dn, info, packet);
*/
struct cflayer {
struct cflayer *up;
struct cflayer *dn;
struct list_head node;
/*
* receive() - Receive Function (non-blocking).
* Contract: Each layer must implement a receive function passing the
* CAIF packets upwards in the stack.
* Packet handling rules:
* - The CAIF packet (cfpkt) ownership is passed to the
* called receive function. This means that the
* packet cannot be accessed after passing it to the
* above layer using up->receive().
*
* - If parsing of the packet fails, the packet must be
* destroyed and negative error code returned
* from the function.
* EXCEPTION: If the framing layer (cffrml) returns
* -EILSEQ, the packet is not freed.
*
* - If parsing succeeds (and above layers return OK) then
* the function must return a value >= 0.
*
* Returns result < 0 indicates an error, 0 or positive value
* indicates success.
*
* @layr: Pointer to the current layer the receive function is
* implemented for (this pointer).
* @cfpkt: Pointer to CaifPacket to be handled.
*/
int (*receive)(struct cflayer *layr, struct cfpkt *cfpkt);
/*
* transmit() - Transmit Function (non-blocking).
* Contract: Each layer must implement a transmit function passing the
* CAIF packet downwards in the stack.
* Packet handling rules:
* - The CAIF packet (cfpkt) ownership is passed to the
* transmit function. This means that the packet
* cannot be accessed after passing it to the below
* layer using dn->transmit().
*
* - Upon error the packet ownership is still passed on,
* so the packet shall be freed where error is detected.
* Callers of the transmit function shall not free packets,
* but errors shall be returned.
*
* - Return value less than zero means error, zero or
* greater than zero means OK.
*
* Returns result < 0 indicates an error, 0 or positive value
* indicates success.
*
* @layr: Pointer to the current layer the receive function
* isimplemented for (this pointer).
* @cfpkt: Pointer to CaifPacket to be handled.
*/
int (*transmit) (struct cflayer *layr, struct cfpkt *cfpkt);
/*
* cttrlcmd() - Control Function upwards in CAIF Stack (non-blocking).
* Used for signaling responses (CAIF_CTRLCMD_*_RSP)
* and asynchronous events from the modem (CAIF_CTRLCMD_*_IND)
*
* @layr: Pointer to the current layer the receive function
* is implemented for (this pointer).
* @ctrl: Control Command.
*/
void (*ctrlcmd) (struct cflayer *layr, enum caif_ctrlcmd ctrl,
int phyid);
/*
* modemctrl() - Control Function used for controlling the modem.
* Used to signal down-wards in the CAIF stack.
* Returns 0 on success, < 0 upon failure.
*
* @layr: Pointer to the current layer the receive function
* is implemented for (this pointer).
* @ctrl: Control Command.
*/
int (*modemcmd) (struct cflayer *layr, enum caif_modemcmd ctrl);
unsigned int id;
char name[CAIF_LAYER_NAME_SZ];
};
/**
* layer_set_up() - Set the up pointer for a specified layer.
* @layr: Layer where up pointer shall be set.
* @above: Layer above.
*/
#define layer_set_up(layr, above) ((layr)->up = (struct cflayer *)(above))
/**
* layer_set_dn() - Set the down pointer for a specified layer.
* @layr: Layer where down pointer shall be set.
* @below: Layer below.
*/
#define layer_set_dn(layr, below) ((layr)->dn = (struct cflayer *)(below))
/**
* struct dev_info - Physical Device info information about physical layer.
* @dev: Pointer to native physical device.
* @id: Physical ID of the physical connection used by the
* logical CAIF connection. Used by service layers to
* identify their physical id to Caif MUX (CFMUXL)so
* that the MUX can add the correct physical ID to the
* packet.
*/
struct dev_info {
void *dev;
unsigned int id;
};
/**
* struct caif_payload_info - Payload information embedded in packet (sk_buff).
*
* @dev_info: Information about the receiving device.
*
* @hdr_len: Header length, used to align pay load on 32bit boundary.
*
* @channel_id: Channel ID of the logical CAIF connection.
* Used by mux to insert channel id into the caif packet.
*/
struct caif_payload_info {
struct dev_info *dev_info;
unsigned short hdr_len;
unsigned short channel_id;
};
#endif /* CAIF_LAYER_H_ */
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