kernel_optimize_test/include/linux/ti_wilink_st.h
Gustavo A. R. Silva 4ea19ecf32 ti_wilink_st.h: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
2020-04-18 15:44:56 -05:00

440 lines
14 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Shared Transport Header file
* To be included by the protocol stack drivers for
* Texas Instruments BT,FM and GPS combo chip drivers
* and also serves the sub-modules of the shared transport driver.
*
* Copyright (C) 2009-2010 Texas Instruments
* Author: Pavan Savoy <pavan_savoy@ti.com>
*/
#ifndef TI_WILINK_ST_H
#define TI_WILINK_ST_H
#include <linux/skbuff.h>
/**
* enum proto-type - The protocol on WiLink chips which share a
* common physical interface like UART.
*/
enum proto_type {
ST_BT,
ST_FM,
ST_GPS,
ST_MAX_CHANNELS = 16,
};
/**
* struct st_proto_s - Per Protocol structure from BT/FM/GPS to ST
* @type: type of the protocol being registered among the
* available proto_type(BT, FM, GPS the protocol which share TTY).
* @recv: the receiver callback pointing to a function in the
* protocol drivers called by the ST driver upon receiving
* relevant data.
* @match_packet: reserved for future use, to make ST more generic
* @reg_complete_cb: callback handler pointing to a function in protocol
* handler called by ST when the pending registrations are complete.
* The registrations are marked pending, in situations when fw
* download is in progress.
* @write: pointer to function in ST provided to protocol drivers from ST,
* to be made use when protocol drivers have data to send to TTY.
* @priv_data: privdate data holder for the protocol drivers, sent
* from the protocol drivers during registration, and sent back on
* reg_complete_cb and recv.
* @chnl_id: channel id the protocol driver is interested in, the channel
* id is nothing but the 1st byte of the packet in UART frame.
* @max_frame_size: size of the largest frame the protocol can receive.
* @hdr_len: length of the header structure of the protocol.
* @offset_len_in_hdr: this provides the offset of the length field in the
* header structure of the protocol header, to assist ST to know
* how much to receive, if the data is split across UART frames.
* @len_size: whether the length field inside the header is 2 bytes
* or 1 byte.
* @reserve: the number of bytes ST needs to reserve in the skb being
* prepared for the protocol driver.
*/
struct st_proto_s {
enum proto_type type;
long (*recv) (void *, struct sk_buff *);
unsigned char (*match_packet) (const unsigned char *data);
void (*reg_complete_cb) (void *, int data);
long (*write) (struct sk_buff *skb);
void *priv_data;
unsigned char chnl_id;
unsigned short max_frame_size;
unsigned char hdr_len;
unsigned char offset_len_in_hdr;
unsigned char len_size;
unsigned char reserve;
};
extern long st_register(struct st_proto_s *);
extern long st_unregister(struct st_proto_s *);
/*
* header information used by st_core.c
*/
/* states of protocol list */
#define ST_NOTEMPTY 1
#define ST_EMPTY 0
/*
* possible st_states
*/
#define ST_INITIALIZING 1
#define ST_REG_IN_PROGRESS 2
#define ST_REG_PENDING 3
#define ST_WAITING_FOR_RESP 4
/**
* struct st_data_s - ST core internal structure
* @st_state: different states of ST like initializing, registration
* in progress, this is mainly used to return relevant err codes
* when protocol drivers are registering. It is also used to track
* the recv function, as in during fw download only HCI events
* can occur , where as during other times other events CH8, CH9
* can occur.
* @tty: tty provided by the TTY core for line disciplines.
* @tx_skb: If for some reason the tty's write returns lesser bytes written
* then to maintain the rest of data to be written on next instance.
* This needs to be protected, hence the lock inside wakeup func.
* @tx_state: if the data is being written onto the TTY and protocol driver
* wants to send more, queue up data and mark that there is
* more data to send.
* @list: the list of protocols registered, only MAX can exist, one protocol
* can register only once.
* @rx_state: states to be maintained inside st's tty receive
* @rx_count: count to be maintained inside st's tty receieve
* @rx_skb: the skb where all data for a protocol gets accumulated,
* since tty might not call receive when a complete event packet
* is received, the states, count and the skb needs to be maintained.
* @rx_chnl: the channel ID for which the data is getting accumalated for.
* @txq: the list of skbs which needs to be sent onto the TTY.
* @tx_waitq: if the chip is not in AWAKE state, the skbs needs to be queued
* up in here, PM(WAKEUP_IND) data needs to be sent and then the skbs
* from waitq can be moved onto the txq.
* Needs locking too.
* @lock: the lock to protect skbs, queues, and ST states.
* @protos_registered: count of the protocols registered, also when 0 the
* chip enable gpio can be toggled, and when it changes to 1 the fw
* needs to be downloaded to initialize chip side ST.
* @ll_state: the various PM states the chip can be, the states are notified
* to us, when the chip sends relevant PM packets(SLEEP_IND, WAKE_IND).
* @kim_data: reference to the parent encapsulating structure.
*
*/
struct st_data_s {
unsigned long st_state;
struct sk_buff *tx_skb;
#define ST_TX_SENDING 1
#define ST_TX_WAKEUP 2
unsigned long tx_state;
struct st_proto_s *list[ST_MAX_CHANNELS];
bool is_registered[ST_MAX_CHANNELS];
unsigned long rx_state;
unsigned long rx_count;
struct sk_buff *rx_skb;
unsigned char rx_chnl;
struct sk_buff_head txq, tx_waitq;
spinlock_t lock;
unsigned char protos_registered;
unsigned long ll_state;
void *kim_data;
struct tty_struct *tty;
struct work_struct work_write_wakeup;
};
/*
* wrapper around tty->ops->write_room to check
* availability during firmware download
*/
int st_get_uart_wr_room(struct st_data_s *st_gdata);
/**
* st_int_write -
* point this to tty->driver->write or tty->ops->write
* depending upon the kernel version
*/
int st_int_write(struct st_data_s*, const unsigned char*, int);
/**
* st_write -
* internal write function, passed onto protocol drivers
* via the write function ptr of protocol struct
*/
long st_write(struct sk_buff *);
/* function to be called from ST-LL */
void st_ll_send_frame(enum proto_type, struct sk_buff *);
/* internal wake up function */
void st_tx_wakeup(struct st_data_s *st_data);
/* init, exit entry funcs called from KIM */
int st_core_init(struct st_data_s **);
void st_core_exit(struct st_data_s *);
/* ask for reference from KIM */
void st_kim_ref(struct st_data_s **, int);
#define GPS_STUB_TEST
#ifdef GPS_STUB_TEST
int gps_chrdrv_stub_write(const unsigned char*, int);
void gps_chrdrv_stub_init(void);
#endif
/*
* header information used by st_kim.c
*/
/* time in msec to wait for
* line discipline to be installed
*/
#define LDISC_TIME 1000
#define CMD_RESP_TIME 800
#define CMD_WR_TIME 5000
#define MAKEWORD(a, b) ((unsigned short)(((unsigned char)(a)) \
| ((unsigned short)((unsigned char)(b))) << 8))
#define GPIO_HIGH 1
#define GPIO_LOW 0
/* the Power-On-Reset logic, requires to attempt
* to download firmware onto chip more than once
* since the self-test for chip takes a while
*/
#define POR_RETRY_COUNT 5
/**
* struct chip_version - save the chip version
*/
struct chip_version {
unsigned short full;
unsigned short chip;
unsigned short min_ver;
unsigned short maj_ver;
};
#define UART_DEV_NAME_LEN 32
/**
* struct kim_data_s - the KIM internal data, embedded as the
* platform's drv data. One for each ST device in the system.
* @uim_pid: KIM needs to communicate with UIM to request to install
* the ldisc by opening UART when protocol drivers register.
* @kim_pdev: the platform device added in one of the board-XX.c file
* in arch/XX/ directory, 1 for each ST device.
* @kim_rcvd: completion handler to notify when data was received,
* mainly used during fw download, which involves multiple send/wait
* for each of the HCI-VS commands.
* @ldisc_installed: completion handler to notify that the UIM accepted
* the request to install ldisc, notify from tty_open which suggests
* the ldisc was properly installed.
* @resp_buffer: data buffer for the .bts fw file name.
* @fw_entry: firmware class struct to request/release the fw.
* @rx_state: the rx state for kim's receive func during fw download.
* @rx_count: the rx count for the kim's receive func during fw download.
* @rx_skb: all of fw data might not come at once, and hence data storage for
* whole of the fw response, only HCI_EVENTs and hence diff from ST's
* response.
* @core_data: ST core's data, which mainly is the tty's disc_data
* @version: chip version available via a sysfs entry.
*
*/
struct kim_data_s {
long uim_pid;
struct platform_device *kim_pdev;
struct completion kim_rcvd, ldisc_installed;
char resp_buffer[30];
const struct firmware *fw_entry;
unsigned nshutdown;
unsigned long rx_state;
unsigned long rx_count;
struct sk_buff *rx_skb;
struct st_data_s *core_data;
struct chip_version version;
unsigned char ldisc_install;
unsigned char dev_name[UART_DEV_NAME_LEN + 1];
unsigned flow_cntrl;
unsigned baud_rate;
};
/**
* functions called when 1 of the protocol drivers gets
* registered, these need to communicate with UIM to request
* ldisc installed, read chip_version, download relevant fw
*/
long st_kim_start(void *);
long st_kim_stop(void *);
void st_kim_complete(void *);
void kim_st_list_protocols(struct st_data_s *, void *);
void st_kim_recv(void *, const unsigned char *, long);
/*
* BTS headers
*/
#define ACTION_SEND_COMMAND 1
#define ACTION_WAIT_EVENT 2
#define ACTION_SERIAL 3
#define ACTION_DELAY 4
#define ACTION_RUN_SCRIPT 5
#define ACTION_REMARKS 6
/**
* struct bts_header - the fw file is NOT binary which can
* be sent onto TTY as is. The .bts is more a script
* file which has different types of actions.
* Each such action needs to be parsed by the KIM and
* relevant procedure to be called.
*/
struct bts_header {
u32 magic;
u32 version;
u8 future[24];
u8 actions[];
} __attribute__ ((packed));
/**
* struct bts_action - Each .bts action has its own type of
* data.
*/
struct bts_action {
u16 type;
u16 size;
u8 data[];
} __attribute__ ((packed));
struct bts_action_send {
u8 data[0];
} __attribute__ ((packed));
struct bts_action_wait {
u32 msec;
u32 size;
u8 data[];
} __attribute__ ((packed));
struct bts_action_delay {
u32 msec;
} __attribute__ ((packed));
struct bts_action_serial {
u32 baud;
u32 flow_control;
} __attribute__ ((packed));
/**
* struct hci_command - the HCI-VS for intrepreting
* the change baud rate of host-side UART, which
* needs to be ignored, since UIM would do that
* when it receives request from KIM for ldisc installation.
*/
struct hci_command {
u8 prefix;
u16 opcode;
u8 plen;
u32 speed;
} __attribute__ ((packed));
/*
* header information used by st_ll.c
*/
/* ST LL receiver states */
#define ST_W4_PACKET_TYPE 0
#define ST_W4_HEADER 1
#define ST_W4_DATA 2
/* ST LL state machines */
#define ST_LL_ASLEEP 0
#define ST_LL_ASLEEP_TO_AWAKE 1
#define ST_LL_AWAKE 2
#define ST_LL_AWAKE_TO_ASLEEP 3
#define ST_LL_INVALID 4
/* different PM notifications coming from chip */
#define LL_SLEEP_IND 0x30
#define LL_SLEEP_ACK 0x31
#define LL_WAKE_UP_IND 0x32
#define LL_WAKE_UP_ACK 0x33
/* initialize and de-init ST LL */
long st_ll_init(struct st_data_s *);
long st_ll_deinit(struct st_data_s *);
/**
* enable/disable ST LL along with KIM start/stop
* called by ST Core
*/
void st_ll_enable(struct st_data_s *);
void st_ll_disable(struct st_data_s *);
/**
* various funcs used by ST core to set/get the various PM states
* of the chip.
*/
unsigned long st_ll_getstate(struct st_data_s *);
unsigned long st_ll_sleep_state(struct st_data_s *, unsigned char);
void st_ll_wakeup(struct st_data_s *);
/*
* header information used by st_core.c for FM and GPS
* packet parsing, the bluetooth headers are already available
* at net/bluetooth/
*/
struct fm_event_hdr {
u8 plen;
} __attribute__ ((packed));
#define FM_MAX_FRAME_SIZE 0xFF /* TODO: */
#define FM_EVENT_HDR_SIZE 1 /* size of fm_event_hdr */
#define ST_FM_CH8_PKT 0x8
/* gps stuff */
struct gps_event_hdr {
u8 opcode;
u16 plen;
} __attribute__ ((packed));
/**
* struct ti_st_plat_data - platform data shared between ST driver and
* platform specific board file which adds the ST device.
* @nshutdown_gpio: Host's GPIO line to which chip's BT_EN is connected.
* @dev_name: The UART/TTY name to which chip is interfaced. (eg: /dev/ttyS1)
* @flow_cntrl: Should always be 1, since UART's CTS/RTS is used for PM
* purposes.
* @baud_rate: The baud rate supported by the Host UART controller, this will
* be shared across with the chip via a HCI VS command from User-Space Init
* Mgr application.
* @suspend:
* @resume: legacy PM routines hooked to platform specific board file, so as
* to take chip-host interface specific action.
* @chip_enable:
* @chip_disable: Platform/Interface specific mux mode setting, GPIO
* configuring, Host side PM disabling etc.. can be done here.
* @chip_asleep:
* @chip_awake: Chip specific deep sleep states is communicated to Host
* specific board-xx.c to take actions such as cut UART clocks when chip
* asleep or run host faster when chip awake etc..
*
*/
struct ti_st_plat_data {
u32 nshutdown_gpio;
unsigned char dev_name[UART_DEV_NAME_LEN]; /* uart name */
u32 flow_cntrl; /* flow control flag */
u32 baud_rate;
int (*suspend)(struct platform_device *, pm_message_t);
int (*resume)(struct platform_device *);
int (*chip_enable) (struct kim_data_s *);
int (*chip_disable) (struct kim_data_s *);
int (*chip_asleep) (struct kim_data_s *);
int (*chip_awake) (struct kim_data_s *);
};
#endif /* TI_WILINK_ST_H */