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linux-next/drivers/usb/serial/garmin_gps.c
Mathieu OTHACEHE 0f3083af5f USB: serial: fix returnvar.cocci warnings 
Remove unneeded variables when "0" can be returned.

Generated by: scripts/coccinelle/misc/returnvar.cocci

Signed-off-by: Mathieu OTHACEHE <m.othacehe@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
2016-02-28 14:36:53 +01:00

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/*
* Garmin GPS driver
*
* Copyright (C) 2006-2011 Hermann Kneissel herkne@gmx.de
*
* The latest version of the driver can be found at
* http://sourceforge.net/projects/garmin-gps/
*
* This driver has been derived from v2.1 of the visor driver.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111 USA
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/timer.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <linux/atomic.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
/* the mode to be set when the port ist opened */
static int initial_mode = 1;
#define GARMIN_VENDOR_ID 0x091E
/*
* Version Information
*/
#define VERSION_MAJOR 0
#define VERSION_MINOR 36
#define _STR(s) #s
#define _DRIVER_VERSION(a, b) "v" _STR(a) "." _STR(b)
#define DRIVER_VERSION _DRIVER_VERSION(VERSION_MAJOR, VERSION_MINOR)
#define DRIVER_AUTHOR "hermann kneissel"
#define DRIVER_DESC "garmin gps driver"
/* error codes returned by the driver */
#define EINVPKT 1000 /* invalid packet structure */
/* size of the header of a packet using the usb protocol */
#define GARMIN_PKTHDR_LENGTH 12
/* max. possible size of a packet using the serial protocol */
#define MAX_SERIAL_PKT_SIZ (3 + 255 + 3)
/* max. possible size of a packet with worst case stuffing */
#define MAX_SERIAL_PKT_SIZ_STUFFED (MAX_SERIAL_PKT_SIZ + 256)
/* size of a buffer able to hold a complete (no stuffing) packet
* (the document protocol does not contain packets with a larger
* size, but in theory a packet may be 64k+12 bytes - if in
* later protocol versions larger packet sizes occur, this value
* should be increased accordingly, so the input buffer is always
* large enough the store a complete packet inclusive header) */
#define GPS_IN_BUFSIZ (GARMIN_PKTHDR_LENGTH+MAX_SERIAL_PKT_SIZ)
/* size of a buffer able to hold a complete (incl. stuffing) packet */
#define GPS_OUT_BUFSIZ (GARMIN_PKTHDR_LENGTH+MAX_SERIAL_PKT_SIZ_STUFFED)
/* where to place the packet id of a serial packet, so we can
* prepend the usb-packet header without the need to move the
* packets data */
#define GSP_INITIAL_OFFSET (GARMIN_PKTHDR_LENGTH-2)
/* max. size of incoming private packets (header+1 param) */
#define PRIVPKTSIZ (GARMIN_PKTHDR_LENGTH+4)
#define GARMIN_LAYERID_TRANSPORT 0
#define GARMIN_LAYERID_APPL 20
/* our own layer-id to use for some control mechanisms */
#define GARMIN_LAYERID_PRIVATE 0x01106E4B
#define GARMIN_PKTID_PVT_DATA 51
#define GARMIN_PKTID_L001_COMMAND_DATA 10
#define CMND_ABORT_TRANSFER 0
/* packet ids used in private layer */
#define PRIV_PKTID_SET_DEBUG 1
#define PRIV_PKTID_SET_MODE 2
#define PRIV_PKTID_INFO_REQ 3
#define PRIV_PKTID_INFO_RESP 4
#define PRIV_PKTID_RESET_REQ 5
#define PRIV_PKTID_SET_DEF_MODE 6
#define ETX 0x03
#define DLE 0x10
#define ACK 0x06
#define NAK 0x15
/* structure used to queue incoming packets */
struct garmin_packet {
struct list_head list;
int seq;
/* the real size of the data array, always > 0 */
int size;
__u8 data[1];
};
/* structure used to keep the current state of the driver */
struct garmin_data {
__u8 state;
__u16 flags;
__u8 mode;
__u8 count;
__u8 pkt_id;
__u32 serial_num;
struct timer_list timer;
struct usb_serial_port *port;
int seq_counter;
int insize;
int outsize;
__u8 inbuffer [GPS_IN_BUFSIZ]; /* tty -> usb */
__u8 outbuffer[GPS_OUT_BUFSIZ]; /* usb -> tty */
__u8 privpkt[4*6];
spinlock_t lock;
struct list_head pktlist;
};
#define STATE_NEW 0
#define STATE_INITIAL_DELAY 1
#define STATE_TIMEOUT 2
#define STATE_SESSION_REQ1 3
#define STATE_SESSION_REQ2 4
#define STATE_ACTIVE 5
#define STATE_RESET 8
#define STATE_DISCONNECTED 9
#define STATE_WAIT_TTY_ACK 10
#define STATE_GSP_WAIT_DATA 11
#define MODE_NATIVE 0
#define MODE_GARMIN_SERIAL 1
/* Flags used in garmin_data.flags: */
#define FLAGS_SESSION_REPLY_MASK 0x00C0
#define FLAGS_SESSION_REPLY1_SEEN 0x0080
#define FLAGS_SESSION_REPLY2_SEEN 0x0040
#define FLAGS_BULK_IN_ACTIVE 0x0020
#define FLAGS_BULK_IN_RESTART 0x0010
#define FLAGS_THROTTLED 0x0008
#define APP_REQ_SEEN 0x0004
#define APP_RESP_SEEN 0x0002
#define CLEAR_HALT_REQUIRED 0x0001
#define FLAGS_QUEUING 0x0100
#define FLAGS_DROP_DATA 0x0800
#define FLAGS_GSP_SKIP 0x1000
#define FLAGS_GSP_DLESEEN 0x2000
/* function prototypes */
static int gsp_next_packet(struct garmin_data *garmin_data_p);
static int garmin_write_bulk(struct usb_serial_port *port,
const unsigned char *buf, int count,
int dismiss_ack);
/* some special packets to be send or received */
static unsigned char const GARMIN_START_SESSION_REQ[]
= { 0, 0, 0, 0, 5, 0, 0, 0, 0, 0, 0, 0 };
static unsigned char const GARMIN_START_SESSION_REPLY[]
= { 0, 0, 0, 0, 6, 0, 0, 0, 4, 0, 0, 0 };
static unsigned char const GARMIN_BULK_IN_AVAIL_REPLY[]
= { 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0 };
static unsigned char const GARMIN_APP_LAYER_REPLY[]
= { 0x14, 0, 0, 0 };
static unsigned char const GARMIN_START_PVT_REQ[]
= { 20, 0, 0, 0, 10, 0, 0, 0, 2, 0, 0, 0, 49, 0 };
static unsigned char const GARMIN_STOP_PVT_REQ[]
= { 20, 0, 0, 0, 10, 0, 0, 0, 2, 0, 0, 0, 50, 0 };
static unsigned char const GARMIN_STOP_TRANSFER_REQ[]
= { 20, 0, 0, 0, 10, 0, 0, 0, 2, 0, 0, 0, 0, 0 };
static unsigned char const GARMIN_STOP_TRANSFER_REQ_V2[]
= { 20, 0, 0, 0, 10, 0, 0, 0, 1, 0, 0, 0, 0 };
static unsigned char const PRIVATE_REQ[]
= { 0x4B, 0x6E, 0x10, 0x01, 0xFF, 0, 0, 0, 0xFF, 0, 0, 0 };
static const struct usb_device_id id_table[] = {
/* the same device id seems to be used by all
usb enabled GPS devices */
{ USB_DEVICE(GARMIN_VENDOR_ID, 3) },
{ } /* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, id_table);
static inline int getLayerId(const __u8 *usbPacket)
{
return __le32_to_cpup((__le32 *)(usbPacket));
}
static inline int getPacketId(const __u8 *usbPacket)
{
return __le32_to_cpup((__le32 *)(usbPacket+4));
}
static inline int getDataLength(const __u8 *usbPacket)
{
return __le32_to_cpup((__le32 *)(usbPacket+8));
}
/*
* check if the usb-packet in buf contains an abort-transfer command.
* (if yes, all queued data will be dropped)
*/
static inline int isAbortTrfCmnd(const unsigned char *buf)
{
if (memcmp(buf, GARMIN_STOP_TRANSFER_REQ,
sizeof(GARMIN_STOP_TRANSFER_REQ)) == 0 ||
memcmp(buf, GARMIN_STOP_TRANSFER_REQ_V2,
sizeof(GARMIN_STOP_TRANSFER_REQ_V2)) == 0)
return 1;
else
return 0;
}
static void send_to_tty(struct usb_serial_port *port,
char *data, unsigned int actual_length)
{
if (actual_length) {
usb_serial_debug_data(&port->dev, __func__, actual_length, data);
tty_insert_flip_string(&port->port, data, actual_length);
tty_flip_buffer_push(&port->port);
}
}
/******************************************************************************
* packet queue handling
******************************************************************************/
/*
* queue a received (usb-)packet for later processing
*/
static int pkt_add(struct garmin_data *garmin_data_p,
unsigned char *data, unsigned int data_length)
{
int state = 0;
int result = 0;
unsigned long flags;
struct garmin_packet *pkt;
/* process only packets containing data ... */
if (data_length) {
pkt = kmalloc(sizeof(struct garmin_packet)+data_length,
GFP_ATOMIC);
if (!pkt)
return 0;
pkt->size = data_length;
memcpy(pkt->data, data, data_length);
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->flags |= FLAGS_QUEUING;
result = list_empty(&garmin_data_p->pktlist);
pkt->seq = garmin_data_p->seq_counter++;
list_add_tail(&pkt->list, &garmin_data_p->pktlist);
state = garmin_data_p->state;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
dev_dbg(&garmin_data_p->port->dev,
"%s - added: pkt: %d - %d bytes\n", __func__,
pkt->seq, data_length);
/* in serial mode, if someone is waiting for data from
the device, convert and send the next packet to tty. */
if (result && (state == STATE_GSP_WAIT_DATA))
gsp_next_packet(garmin_data_p);
}
return result;
}
/* get the next pending packet */
static struct garmin_packet *pkt_pop(struct garmin_data *garmin_data_p)
{
unsigned long flags;
struct garmin_packet *result = NULL;
spin_lock_irqsave(&garmin_data_p->lock, flags);
if (!list_empty(&garmin_data_p->pktlist)) {
result = (struct garmin_packet *)garmin_data_p->pktlist.next;
list_del(&result->list);
}
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
return result;
}
/* free up all queued data */
static void pkt_clear(struct garmin_data *garmin_data_p)
{
unsigned long flags;
struct garmin_packet *result = NULL;
spin_lock_irqsave(&garmin_data_p->lock, flags);
while (!list_empty(&garmin_data_p->pktlist)) {
result = (struct garmin_packet *)garmin_data_p->pktlist.next;
list_del(&result->list);
kfree(result);
}
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
}
/******************************************************************************
* garmin serial protocol handling handling
******************************************************************************/
/* send an ack packet back to the tty */
static int gsp_send_ack(struct garmin_data *garmin_data_p, __u8 pkt_id)
{
__u8 pkt[10];
__u8 cksum = 0;
__u8 *ptr = pkt;
unsigned l = 0;
dev_dbg(&garmin_data_p->port->dev, "%s - pkt-id: 0x%X.\n", __func__,
pkt_id);
*ptr++ = DLE;
*ptr++ = ACK;
cksum += ACK;
*ptr++ = 2;
cksum += 2;
*ptr++ = pkt_id;
cksum += pkt_id;
if (pkt_id == DLE)
*ptr++ = DLE;
*ptr++ = 0;
*ptr++ = (-cksum) & 0xFF;
*ptr++ = DLE;
*ptr++ = ETX;
l = ptr-pkt;
send_to_tty(garmin_data_p->port, pkt, l);
return 0;
}
/*
* called for a complete packet received from tty layer
*
* the complete packet (pktid ... cksum) is in garmin_data_p->inbuf starting
* at GSP_INITIAL_OFFSET.
*
* count - number of bytes in the input buffer including space reserved for
* the usb header: GSP_INITIAL_OFFSET + number of bytes in packet
* (including pkt-id, data-length a. cksum)
*/
static int gsp_rec_packet(struct garmin_data *garmin_data_p, int count)
{
struct device *dev = &garmin_data_p->port->dev;
unsigned long flags;
const __u8 *recpkt = garmin_data_p->inbuffer+GSP_INITIAL_OFFSET;
__le32 *usbdata = (__le32 *) garmin_data_p->inbuffer;
int cksum = 0;
int n = 0;
int pktid = recpkt[0];
int size = recpkt[1];
usb_serial_debug_data(&garmin_data_p->port->dev, __func__,
count-GSP_INITIAL_OFFSET, recpkt);
if (size != (count-GSP_INITIAL_OFFSET-3)) {
dev_dbg(dev, "%s - invalid size, expected %d bytes, got %d\n",
__func__, size, (count-GSP_INITIAL_OFFSET-3));
return -EINVPKT;
}
cksum += *recpkt++;
cksum += *recpkt++;
/* sanity check, remove after test ... */
if ((__u8 *)&(usbdata[3]) != recpkt) {
dev_dbg(dev, "%s - ptr mismatch %p - %p\n", __func__,
&(usbdata[4]), recpkt);
return -EINVPKT;
}
while (n < size) {
cksum += *recpkt++;
n++;
}
if (((cksum + *recpkt) & 0xff) != 0) {
dev_dbg(dev, "%s - invalid checksum, expected %02x, got %02x\n",
__func__, -cksum & 0xff, *recpkt);
return -EINVPKT;
}
usbdata[0] = __cpu_to_le32(GARMIN_LAYERID_APPL);
usbdata[1] = __cpu_to_le32(pktid);
usbdata[2] = __cpu_to_le32(size);
garmin_write_bulk(garmin_data_p->port, garmin_data_p->inbuffer,
GARMIN_PKTHDR_LENGTH+size, 0);
/* if this was an abort-transfer command, flush all
queued data. */
if (isAbortTrfCmnd(garmin_data_p->inbuffer)) {
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->flags |= FLAGS_DROP_DATA;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
pkt_clear(garmin_data_p);
}
return count;
}
/*
* Called for data received from tty
*
* buf contains the data read, it may span more than one packet or even
* incomplete packets
*
* input record should be a serial-record, but it may not be complete.
* Copy it into our local buffer, until an etx is seen (or an error
* occurs).
* Once the record is complete, convert into a usb packet and send it
* to the bulk pipe, send an ack back to the tty.
*
* If the input is an ack, just send the last queued packet to the
* tty layer.
*
* if the input is an abort command, drop all queued data.
*/
static int gsp_receive(struct garmin_data *garmin_data_p,
const unsigned char *buf, int count)
{
struct device *dev = &garmin_data_p->port->dev;
unsigned long flags;
int offs = 0;
int ack_or_nak_seen = 0;
__u8 *dest;
int size;
/* dleSeen: set if last byte read was a DLE */
int dleSeen;
/* skip: if set, skip incoming data until possible start of
* new packet
*/
int skip;
__u8 data;
spin_lock_irqsave(&garmin_data_p->lock, flags);
dest = garmin_data_p->inbuffer;
size = garmin_data_p->insize;
dleSeen = garmin_data_p->flags & FLAGS_GSP_DLESEEN;
skip = garmin_data_p->flags & FLAGS_GSP_SKIP;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
/* dev_dbg(dev, "%s - dle=%d skip=%d size=%d count=%d\n",
__func__, dleSeen, skip, size, count); */
if (size == 0)
size = GSP_INITIAL_OFFSET;
while (offs < count) {
data = *(buf+offs);
offs++;
if (data == DLE) {
if (skip) { /* start of a new pkt */
skip = 0;
size = GSP_INITIAL_OFFSET;
dleSeen = 1;
} else if (dleSeen) {
dest[size++] = data;
dleSeen = 0;
} else {
dleSeen = 1;
}
} else if (data == ETX) {
if (dleSeen) {
/* packet complete */
data = dest[GSP_INITIAL_OFFSET];
if (data == ACK) {
ack_or_nak_seen = ACK;
dev_dbg(dev, "ACK packet complete.\n");
} else if (data == NAK) {
ack_or_nak_seen = NAK;
dev_dbg(dev, "NAK packet complete.\n");
} else {
dev_dbg(dev, "packet complete - id=0x%X.\n",
data);
gsp_rec_packet(garmin_data_p, size);
}
skip = 1;
size = GSP_INITIAL_OFFSET;
dleSeen = 0;
} else {
dest[size++] = data;
}
} else if (!skip) {
if (dleSeen) {
size = GSP_INITIAL_OFFSET;
dleSeen = 0;
}
dest[size++] = data;
}
if (size >= GPS_IN_BUFSIZ) {
dev_dbg(dev, "%s - packet too large.\n", __func__);
skip = 1;
size = GSP_INITIAL_OFFSET;
dleSeen = 0;
}
}
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->insize = size;
/* copy flags back to structure */
if (skip)
garmin_data_p->flags |= FLAGS_GSP_SKIP;
else
garmin_data_p->flags &= ~FLAGS_GSP_SKIP;
if (dleSeen)
garmin_data_p->flags |= FLAGS_GSP_DLESEEN;
else
garmin_data_p->flags &= ~FLAGS_GSP_DLESEEN;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
if (ack_or_nak_seen) {
if (gsp_next_packet(garmin_data_p) > 0)
garmin_data_p->state = STATE_ACTIVE;
else
garmin_data_p->state = STATE_GSP_WAIT_DATA;
}
return count;
}
/*
* Sends a usb packet to the tty
*
* Assumes, that all packages and at an usb-packet boundary.
*
* return <0 on error, 0 if packet is incomplete or > 0 if packet was sent
*/
static int gsp_send(struct garmin_data *garmin_data_p,
const unsigned char *buf, int count)
{
struct device *dev = &garmin_data_p->port->dev;
const unsigned char *src;
unsigned char *dst;
int pktid = 0;
int datalen = 0;
int cksum = 0;
int i = 0;
int k;
dev_dbg(dev, "%s - state %d - %d bytes.\n", __func__,
garmin_data_p->state, count);
k = garmin_data_p->outsize;
if ((k+count) > GPS_OUT_BUFSIZ) {
dev_dbg(dev, "packet too large\n");
garmin_data_p->outsize = 0;
return -4;
}
memcpy(garmin_data_p->outbuffer+k, buf, count);
k += count;
garmin_data_p->outsize = k;
if (k >= GARMIN_PKTHDR_LENGTH) {
pktid = getPacketId(garmin_data_p->outbuffer);
datalen = getDataLength(garmin_data_p->outbuffer);
i = GARMIN_PKTHDR_LENGTH + datalen;
if (k < i)
return 0;
} else {
return 0;
}
dev_dbg(dev, "%s - %d bytes in buffer, %d bytes in pkt.\n", __func__, k, i);
/* garmin_data_p->outbuffer now contains a complete packet */
usb_serial_debug_data(&garmin_data_p->port->dev, __func__, k,
garmin_data_p->outbuffer);
garmin_data_p->outsize = 0;
if (getLayerId(garmin_data_p->outbuffer) != GARMIN_LAYERID_APPL) {
dev_dbg(dev, "not an application packet (%d)\n",
getLayerId(garmin_data_p->outbuffer));
return -1;
}
if (pktid > 255) {
dev_dbg(dev, "packet-id %d too large\n", pktid);
return -2;
}
if (datalen > 255) {
dev_dbg(dev, "packet-size %d too large\n", datalen);
return -3;
}
/* the serial protocol should be able to handle this packet */
k = 0;
src = garmin_data_p->outbuffer+GARMIN_PKTHDR_LENGTH;
for (i = 0; i < datalen; i++) {
if (*src++ == DLE)
k++;
}
src = garmin_data_p->outbuffer+GARMIN_PKTHDR_LENGTH;
if (k > (GARMIN_PKTHDR_LENGTH-2)) {
/* can't add stuffing DLEs in place, move data to end
of buffer ... */
dst = garmin_data_p->outbuffer+GPS_OUT_BUFSIZ-datalen;
memcpy(dst, src, datalen);
src = dst;
}
dst = garmin_data_p->outbuffer;
*dst++ = DLE;
*dst++ = pktid;
cksum += pktid;
*dst++ = datalen;
cksum += datalen;
if (datalen == DLE)
*dst++ = DLE;
for (i = 0; i < datalen; i++) {
__u8 c = *src++;
*dst++ = c;
cksum += c;
if (c == DLE)
*dst++ = DLE;
}
cksum = -cksum & 0xFF;
*dst++ = cksum;
if (cksum == DLE)
*dst++ = DLE;
*dst++ = DLE;
*dst++ = ETX;
i = dst-garmin_data_p->outbuffer;
send_to_tty(garmin_data_p->port, garmin_data_p->outbuffer, i);
garmin_data_p->pkt_id = pktid;
garmin_data_p->state = STATE_WAIT_TTY_ACK;
return i;
}
/*
* Process the next pending data packet - if there is one
*/
static int gsp_next_packet(struct garmin_data *garmin_data_p)
{
int result = 0;
struct garmin_packet *pkt = NULL;
while ((pkt = pkt_pop(garmin_data_p)) != NULL) {
dev_dbg(&garmin_data_p->port->dev, "%s - next pkt: %d\n", __func__, pkt->seq);
result = gsp_send(garmin_data_p, pkt->data, pkt->size);
if (result > 0) {
kfree(pkt);
return result;
}
kfree(pkt);
}
return result;
}
/******************************************************************************
* garmin native mode
******************************************************************************/
/*
* Called for data received from tty
*
* The input data is expected to be in garmin usb-packet format.
*
* buf contains the data read, it may span more than one packet
* or even incomplete packets
*/
static int nat_receive(struct garmin_data *garmin_data_p,
const unsigned char *buf, int count)
{
unsigned long flags;
__u8 *dest;
int offs = 0;
int result = count;
int len;
while (offs < count) {
/* if buffer contains header, copy rest of data */
if (garmin_data_p->insize >= GARMIN_PKTHDR_LENGTH)
len = GARMIN_PKTHDR_LENGTH
+getDataLength(garmin_data_p->inbuffer);
else
len = GARMIN_PKTHDR_LENGTH;
if (len >= GPS_IN_BUFSIZ) {
/* seems to be an invalid packet, ignore rest
of input */
dev_dbg(&garmin_data_p->port->dev,
"%s - packet size too large: %d\n",
__func__, len);
garmin_data_p->insize = 0;
count = 0;
result = -EINVPKT;
} else {
len -= garmin_data_p->insize;
if (len > (count-offs))
len = (count-offs);
if (len > 0) {
dest = garmin_data_p->inbuffer
+ garmin_data_p->insize;
memcpy(dest, buf+offs, len);
garmin_data_p->insize += len;
offs += len;
}
}
/* do we have a complete packet ? */
if (garmin_data_p->insize >= GARMIN_PKTHDR_LENGTH) {
len = GARMIN_PKTHDR_LENGTH+
getDataLength(garmin_data_p->inbuffer);
if (garmin_data_p->insize >= len) {
garmin_write_bulk(garmin_data_p->port,
garmin_data_p->inbuffer,
len, 0);
garmin_data_p->insize = 0;
/* if this was an abort-transfer command,
flush all queued data. */
if (isAbortTrfCmnd(garmin_data_p->inbuffer)) {
spin_lock_irqsave(&garmin_data_p->lock,
flags);
garmin_data_p->flags |= FLAGS_DROP_DATA;
spin_unlock_irqrestore(
&garmin_data_p->lock, flags);
pkt_clear(garmin_data_p);
}
}
}
}
return result;
}
/******************************************************************************
* private packets
******************************************************************************/
static void priv_status_resp(struct usb_serial_port *port)
{
struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
__le32 *pkt = (__le32 *)garmin_data_p->privpkt;
pkt[0] = __cpu_to_le32(GARMIN_LAYERID_PRIVATE);
pkt[1] = __cpu_to_le32(PRIV_PKTID_INFO_RESP);
pkt[2] = __cpu_to_le32(12);
pkt[3] = __cpu_to_le32(VERSION_MAJOR << 16 | VERSION_MINOR);
pkt[4] = __cpu_to_le32(garmin_data_p->mode);
pkt[5] = __cpu_to_le32(garmin_data_p->serial_num);
send_to_tty(port, (__u8 *)pkt, 6 * 4);
}
/******************************************************************************
* Garmin specific driver functions
******************************************************************************/
static int process_resetdev_request(struct usb_serial_port *port)
{
unsigned long flags;
int status;
struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->flags &= ~(CLEAR_HALT_REQUIRED);
garmin_data_p->state = STATE_RESET;
garmin_data_p->serial_num = 0;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
usb_kill_urb(port->interrupt_in_urb);
dev_dbg(&port->dev, "%s - usb_reset_device\n", __func__);
status = usb_reset_device(port->serial->dev);
if (status)
dev_dbg(&port->dev, "%s - usb_reset_device failed: %d\n",
__func__, status);
return status;
}
/*
* clear all cached data
*/
static int garmin_clear(struct garmin_data *garmin_data_p)
{
unsigned long flags;
/* flush all queued data */
pkt_clear(garmin_data_p);
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->insize = 0;
garmin_data_p->outsize = 0;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
return 0;
}
static int garmin_init_session(struct usb_serial_port *port)
{
struct usb_serial *serial = port->serial;
struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
int status = 0;
int i = 0;
if (status == 0) {
usb_kill_urb(port->interrupt_in_urb);
dev_dbg(&serial->dev->dev, "%s - adding interrupt input\n", __func__);
status = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
if (status)
dev_err(&serial->dev->dev,
"%s - failed submitting interrupt urb, error %d\n",
__func__, status);
}
/*
* using the initialization method from gpsbabel. See comments in
* gpsbabel/jeeps/gpslibusb.c gusb_reset_toggles()
*/
if (status == 0) {
dev_dbg(&serial->dev->dev, "%s - starting session ...\n", __func__);
garmin_data_p->state = STATE_ACTIVE;
for (i = 0; i < 3; i++) {
status = garmin_write_bulk(port,
GARMIN_START_SESSION_REQ,
sizeof(GARMIN_START_SESSION_REQ), 0);
if (status < 0)
break;
}
if (status > 0)
status = 0;
}
return status;
}
static int garmin_open(struct tty_struct *tty, struct usb_serial_port *port)
{
unsigned long flags;
int status = 0;
struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->mode = initial_mode;
garmin_data_p->count = 0;
garmin_data_p->flags &= FLAGS_SESSION_REPLY1_SEEN;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
/* shutdown any bulk reads that might be going on */
usb_kill_urb(port->write_urb);
usb_kill_urb(port->read_urb);
if (garmin_data_p->state == STATE_RESET)
status = garmin_init_session(port);
garmin_data_p->state = STATE_ACTIVE;
return status;
}
static void garmin_close(struct usb_serial_port *port)
{
struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
dev_dbg(&port->dev, "%s - mode=%d state=%d flags=0x%X\n",
__func__, garmin_data_p->mode, garmin_data_p->state,
garmin_data_p->flags);
garmin_clear(garmin_data_p);
/* shutdown our urbs */
usb_kill_urb(port->read_urb);
usb_kill_urb(port->write_urb);
/* keep reset state so we know that we must start a new session */
if (garmin_data_p->state != STATE_RESET)
garmin_data_p->state = STATE_DISCONNECTED;
}
static void garmin_write_bulk_callback(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
if (port) {
struct garmin_data *garmin_data_p =
usb_get_serial_port_data(port);
if (getLayerId(urb->transfer_buffer) == GARMIN_LAYERID_APPL) {
if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
gsp_send_ack(garmin_data_p,
((__u8 *)urb->transfer_buffer)[4]);
}
}
usb_serial_port_softint(port);
}
/* Ignore errors that resulted from garmin_write_bulk with
dismiss_ack = 1 */
/* free up the transfer buffer, as usb_free_urb() does not do this */
kfree(urb->transfer_buffer);
}
static int garmin_write_bulk(struct usb_serial_port *port,
const unsigned char *buf, int count,
int dismiss_ack)
{
unsigned long flags;
struct usb_serial *serial = port->serial;
struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
struct urb *urb;
unsigned char *buffer;
int status;
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->flags &= ~FLAGS_DROP_DATA;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
buffer = kmalloc(count, GFP_ATOMIC);
if (!buffer)
return -ENOMEM;
urb = usb_alloc_urb(0, GFP_ATOMIC);
if (!urb) {
kfree(buffer);
return -ENOMEM;
}
memcpy(buffer, buf, count);
usb_serial_debug_data(&port->dev, __func__, count, buffer);
usb_fill_bulk_urb(urb, serial->dev,
usb_sndbulkpipe(serial->dev,
port->bulk_out_endpointAddress),
buffer, count,
garmin_write_bulk_callback,
dismiss_ack ? NULL : port);
urb->transfer_flags |= URB_ZERO_PACKET;
if (getLayerId(buffer) == GARMIN_LAYERID_APPL) {
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->flags |= APP_REQ_SEEN;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
pkt_clear(garmin_data_p);
garmin_data_p->state = STATE_GSP_WAIT_DATA;
}
}
/* send it down the pipe */
status = usb_submit_urb(urb, GFP_ATOMIC);
if (status) {
dev_err(&port->dev,
"%s - usb_submit_urb(write bulk) failed with status = %d\n",
__func__, status);
count = status;
}
/* we are done with this urb, so let the host driver
* really free it when it is finished with it */
usb_free_urb(urb);
return count;
}
static int garmin_write(struct tty_struct *tty, struct usb_serial_port *port,
const unsigned char *buf, int count)
{
struct device *dev = &port->dev;
int pktid, pktsiz, len;
struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
__le32 *privpkt = (__le32 *)garmin_data_p->privpkt;
usb_serial_debug_data(dev, __func__, count, buf);
if (garmin_data_p->state == STATE_RESET)
return -EIO;
/* check for our private packets */
if (count >= GARMIN_PKTHDR_LENGTH) {
len = PRIVPKTSIZ;
if (count < len)
len = count;
memcpy(garmin_data_p->privpkt, buf, len);
pktsiz = getDataLength(garmin_data_p->privpkt);
pktid = getPacketId(garmin_data_p->privpkt);
if (count == (GARMIN_PKTHDR_LENGTH + pktsiz) &&
getLayerId(garmin_data_p->privpkt) ==
GARMIN_LAYERID_PRIVATE) {
dev_dbg(dev, "%s - processing private request %d\n",
__func__, pktid);
/* drop all unfinished transfers */
garmin_clear(garmin_data_p);
switch (pktid) {
case PRIV_PKTID_SET_MODE:
if (pktsiz != 4)
return -EINVPKT;
garmin_data_p->mode = __le32_to_cpu(privpkt[3]);
dev_dbg(dev, "%s - mode set to %d\n",
__func__, garmin_data_p->mode);
break;
case PRIV_PKTID_INFO_REQ:
priv_status_resp(port);
break;
case PRIV_PKTID_RESET_REQ:
process_resetdev_request(port);
break;
case PRIV_PKTID_SET_DEF_MODE:
if (pktsiz != 4)
return -EINVPKT;
initial_mode = __le32_to_cpu(privpkt[3]);
dev_dbg(dev, "%s - initial_mode set to %d\n",
__func__,
garmin_data_p->mode);
break;
}
return count;
}
}
if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
return gsp_receive(garmin_data_p, buf, count);
} else { /* MODE_NATIVE */
return nat_receive(garmin_data_p, buf, count);
}
}
static int garmin_write_room(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
/*
* Report back the bytes currently available in the output buffer.
*/
struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
return GPS_OUT_BUFSIZ-garmin_data_p->outsize;
}
static void garmin_read_process(struct garmin_data *garmin_data_p,
unsigned char *data, unsigned data_length,
int bulk_data)
{
unsigned long flags;
if (garmin_data_p->flags & FLAGS_DROP_DATA) {
/* abort-transfer cmd is active */
dev_dbg(&garmin_data_p->port->dev, "%s - pkt dropped\n", __func__);
} else if (garmin_data_p->state != STATE_DISCONNECTED &&
garmin_data_p->state != STATE_RESET) {
/* if throttling is active or postprecessing is required
put the received data in the input queue, otherwise
send it directly to the tty port */
if (garmin_data_p->flags & FLAGS_QUEUING) {
pkt_add(garmin_data_p, data, data_length);
} else if (bulk_data ||
getLayerId(data) == GARMIN_LAYERID_APPL) {
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->flags |= APP_RESP_SEEN;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
pkt_add(garmin_data_p, data, data_length);
} else {
send_to_tty(garmin_data_p->port, data,
data_length);
}
}
/* ignore system layer packets ... */
}
}
static void garmin_read_bulk_callback(struct urb *urb)
{
unsigned long flags;
struct usb_serial_port *port = urb->context;
struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
unsigned char *data = urb->transfer_buffer;
int status = urb->status;
int retval;
if (status) {
dev_dbg(&urb->dev->dev, "%s - nonzero read bulk status received: %d\n",
__func__, status);
return;
}
usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
garmin_read_process(garmin_data_p, data, urb->actual_length, 1);
if (urb->actual_length == 0 &&
(garmin_data_p->flags & FLAGS_BULK_IN_RESTART) != 0) {
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->flags &= ~FLAGS_BULK_IN_RESTART;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
retval = usb_submit_urb(port->read_urb, GFP_ATOMIC);
if (retval)
dev_err(&port->dev,
"%s - failed resubmitting read urb, error %d\n",
__func__, retval);
} else if (urb->actual_length > 0) {
/* Continue trying to read until nothing more is received */
if ((garmin_data_p->flags & FLAGS_THROTTLED) == 0) {
retval = usb_submit_urb(port->read_urb, GFP_ATOMIC);
if (retval)
dev_err(&port->dev,
"%s - failed resubmitting read urb, error %d\n",
__func__, retval);
}
} else {
dev_dbg(&port->dev, "%s - end of bulk data\n", __func__);
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->flags &= ~FLAGS_BULK_IN_ACTIVE;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
}
}
static void garmin_read_int_callback(struct urb *urb)
{
unsigned long flags;
int retval;
struct usb_serial_port *port = urb->context;
struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
unsigned char *data = urb->transfer_buffer;
int status = urb->status;
switch (status) {
case 0:
/* success */
break;
case -ECONNRESET:
case -ENOENT:
case -ESHUTDOWN:
/* this urb is terminated, clean up */
dev_dbg(&urb->dev->dev, "%s - urb shutting down with status: %d\n",
__func__, status);
return;
default:
dev_dbg(&urb->dev->dev, "%s - nonzero urb status received: %d\n",
__func__, status);
return;
}
usb_serial_debug_data(&port->dev, __func__, urb->actual_length,
urb->transfer_buffer);
if (urb->actual_length == sizeof(GARMIN_BULK_IN_AVAIL_REPLY) &&
memcmp(data, GARMIN_BULK_IN_AVAIL_REPLY,
sizeof(GARMIN_BULK_IN_AVAIL_REPLY)) == 0) {
dev_dbg(&port->dev, "%s - bulk data available.\n", __func__);
if ((garmin_data_p->flags & FLAGS_BULK_IN_ACTIVE) == 0) {
/* bulk data available */
retval = usb_submit_urb(port->read_urb, GFP_ATOMIC);
if (retval) {
dev_err(&port->dev,
"%s - failed submitting read urb, error %d\n",
__func__, retval);
} else {
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->flags |= FLAGS_BULK_IN_ACTIVE;
spin_unlock_irqrestore(&garmin_data_p->lock,
flags);
}
} else {
/* bulk-in transfer still active */
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->flags |= FLAGS_BULK_IN_RESTART;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
}
} else if (urb->actual_length == (4+sizeof(GARMIN_START_SESSION_REPLY))
&& memcmp(data, GARMIN_START_SESSION_REPLY,
sizeof(GARMIN_START_SESSION_REPLY)) == 0) {
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->flags |= FLAGS_SESSION_REPLY1_SEEN;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
/* save the serial number */
garmin_data_p->serial_num = __le32_to_cpup(
(__le32 *)(data+GARMIN_PKTHDR_LENGTH));
dev_dbg(&port->dev, "%s - start-of-session reply seen - serial %u.\n",
__func__, garmin_data_p->serial_num);
}
garmin_read_process(garmin_data_p, data, urb->actual_length, 0);
retval = usb_submit_urb(urb, GFP_ATOMIC);
if (retval)
dev_err(&urb->dev->dev,
"%s - Error %d submitting interrupt urb\n",
__func__, retval);
}
/*
* Sends the next queued packt to the tty port (garmin native mode only)
* and then sets a timer to call itself again until all queued data
* is sent.
*/
static int garmin_flush_queue(struct garmin_data *garmin_data_p)
{
unsigned long flags;
struct garmin_packet *pkt;
if ((garmin_data_p->flags & FLAGS_THROTTLED) == 0) {
pkt = pkt_pop(garmin_data_p);
if (pkt != NULL) {
send_to_tty(garmin_data_p->port, pkt->data, pkt->size);
kfree(pkt);
mod_timer(&garmin_data_p->timer, (1)+jiffies);
} else {
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->flags &= ~FLAGS_QUEUING;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
}
}
return 0;
}
static void garmin_throttle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
/* set flag, data received will be put into a queue
for later processing */
spin_lock_irq(&garmin_data_p->lock);
garmin_data_p->flags |= FLAGS_QUEUING|FLAGS_THROTTLED;
spin_unlock_irq(&garmin_data_p->lock);
}
static void garmin_unthrottle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
int status;
spin_lock_irq(&garmin_data_p->lock);
garmin_data_p->flags &= ~FLAGS_THROTTLED;
spin_unlock_irq(&garmin_data_p->lock);
/* in native mode send queued data to tty, in
serial mode nothing needs to be done here */
if (garmin_data_p->mode == MODE_NATIVE)
garmin_flush_queue(garmin_data_p);
if ((garmin_data_p->flags & FLAGS_BULK_IN_ACTIVE) != 0) {
status = usb_submit_urb(port->read_urb, GFP_KERNEL);
if (status)
dev_err(&port->dev,
"%s - failed resubmitting read urb, error %d\n",
__func__, status);
}
}
/*
* The timer is currently only used to send queued packets to
* the tty in cases where the protocol provides no own handshaking
* to initiate the transfer.
*/
static void timeout_handler(unsigned long data)
{
struct garmin_data *garmin_data_p = (struct garmin_data *) data;
/* send the next queued packet to the tty port */
if (garmin_data_p->mode == MODE_NATIVE)
if (garmin_data_p->flags & FLAGS_QUEUING)
garmin_flush_queue(garmin_data_p);
}
static int garmin_port_probe(struct usb_serial_port *port)
{
int status;
struct garmin_data *garmin_data_p;
garmin_data_p = kzalloc(sizeof(struct garmin_data), GFP_KERNEL);
if (!garmin_data_p)
return -ENOMEM;
init_timer(&garmin_data_p->timer);
spin_lock_init(&garmin_data_p->lock);
INIT_LIST_HEAD(&garmin_data_p->pktlist);
/* garmin_data_p->timer.expires = jiffies + session_timeout; */
garmin_data_p->timer.data = (unsigned long)garmin_data_p;
garmin_data_p->timer.function = timeout_handler;
garmin_data_p->port = port;
garmin_data_p->state = 0;
garmin_data_p->flags = 0;
garmin_data_p->count = 0;
usb_set_serial_port_data(port, garmin_data_p);
status = garmin_init_session(port);
return status;
}
static int garmin_port_remove(struct usb_serial_port *port)
{
struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
usb_kill_urb(port->interrupt_in_urb);
del_timer_sync(&garmin_data_p->timer);
kfree(garmin_data_p);
return 0;
}
/* All of the device info needed */
static struct usb_serial_driver garmin_device = {
.driver = {
.owner = THIS_MODULE,
.name = "garmin_gps",
},
.description = "Garmin GPS usb/tty",
.id_table = id_table,
.num_ports = 1,
.open = garmin_open,
.close = garmin_close,
.throttle = garmin_throttle,
.unthrottle = garmin_unthrottle,
.port_probe = garmin_port_probe,
.port_remove = garmin_port_remove,
.write = garmin_write,
.write_room = garmin_write_room,
.write_bulk_callback = garmin_write_bulk_callback,
.read_bulk_callback = garmin_read_bulk_callback,
.read_int_callback = garmin_read_int_callback,
};
static struct usb_serial_driver * const serial_drivers[] = {
&garmin_device, NULL
};
module_usb_serial_driver(serial_drivers, id_table);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
module_param(initial_mode, int, S_IRUGO);
MODULE_PARM_DESC(initial_mode, "Initial mode");
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