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| -rw-r--r-- | include/net/caif/caif_layer.h | 279 |
1 files changed, 279 insertions, 0 deletions
diff --git a/include/net/caif/caif_layer.h b/include/net/caif/caif_layer.h new file mode 100644 index 000000000..51f7bb42a --- /dev/null +++ b/include/net/caif/caif_layer.h @@ -0,0 +1,279 @@ +/* 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 cfpktq; +struct caif_payload_info; +struct caif_packet_funcs; + +#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 failes. 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 funciton. + * @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_ */ |