linux/drivers/hsi/clients/ssi_protocol.c
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   1/*
   2 * ssi_protocol.c
   3 *
   4 * Implementation of the SSI McSAAB improved protocol.
   5 *
   6 * Copyright (C) 2010 Nokia Corporation. All rights reserved.
   7 * Copyright (C) 2013 Sebastian Reichel <sre@kernel.org>
   8 *
   9 * Contact: Carlos Chinea <carlos.chinea@nokia.com>
  10 *
  11 * This program is free software; you can redistribute it and/or
  12 * modify it under the terms of the GNU General Public License
  13 * version 2 as published by the Free Software Foundation.
  14 *
  15 * This program is distributed in the hope that it will be useful, but
  16 * WITHOUT ANY WARRANTY; without even the implied warranty of
  17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18 * General Public License for more details.
  19 *
  20 * You should have received a copy of the GNU General Public License
  21 * along with this program; if not, write to the Free Software
  22 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  23 * 02110-1301 USA
  24 */
  25
  26#include <linux/atomic.h>
  27#include <linux/clk.h>
  28#include <linux/device.h>
  29#include <linux/err.h>
  30#include <linux/gpio.h>
  31#include <linux/if_ether.h>
  32#include <linux/if_arp.h>
  33#include <linux/if_phonet.h>
  34#include <linux/init.h>
  35#include <linux/irq.h>
  36#include <linux/list.h>
  37#include <linux/module.h>
  38#include <linux/netdevice.h>
  39#include <linux/notifier.h>
  40#include <linux/scatterlist.h>
  41#include <linux/skbuff.h>
  42#include <linux/slab.h>
  43#include <linux/spinlock.h>
  44#include <linux/timer.h>
  45#include <linux/hsi/hsi.h>
  46#include <linux/hsi/ssi_protocol.h>
  47
  48void ssi_waketest(struct hsi_client *cl, unsigned int enable);
  49
  50#define SSIP_TXQUEUE_LEN        100
  51#define SSIP_MAX_MTU            65535
  52#define SSIP_DEFAULT_MTU        4000
  53#define PN_MEDIA_SOS            21
  54#define SSIP_MIN_PN_HDR         6       /* FIXME: Revisit */
  55#define SSIP_WDTOUT             2000    /* FIXME: has to be 500 msecs */
  56#define SSIP_KATOUT             15      /* 15 msecs */
  57#define SSIP_MAX_CMDS           5 /* Number of pre-allocated commands buffers */
  58#define SSIP_BYTES_TO_FRAMES(x) ((((x) - 1) >> 2) + 1)
  59#define SSIP_CMT_LOADER_SYNC    0x11223344
  60/*
  61 * SSI protocol command definitions
  62 */
  63#define SSIP_COMMAND(data)      ((data) >> 28)
  64#define SSIP_PAYLOAD(data)      ((data) & 0xfffffff)
  65/* Commands */
  66#define SSIP_SW_BREAK           0
  67#define SSIP_BOOTINFO_REQ       1
  68#define SSIP_BOOTINFO_RESP      2
  69#define SSIP_WAKETEST_RESULT    3
  70#define SSIP_START_TRANS        4
  71#define SSIP_READY              5
  72/* Payloads */
  73#define SSIP_DATA_VERSION(data) ((data) & 0xff)
  74#define SSIP_LOCAL_VERID        1
  75#define SSIP_WAKETEST_OK        0
  76#define SSIP_WAKETEST_FAILED    1
  77#define SSIP_PDU_LENGTH(data)   (((data) >> 8) & 0xffff)
  78#define SSIP_MSG_ID(data)       ((data) & 0xff)
  79/* Generic Command */
  80#define SSIP_CMD(cmd, payload)  (((cmd) << 28) | ((payload) & 0xfffffff))
  81/* Commands for the control channel */
  82#define SSIP_BOOTINFO_REQ_CMD(ver) \
  83                SSIP_CMD(SSIP_BOOTINFO_REQ, SSIP_DATA_VERSION(ver))
  84#define SSIP_BOOTINFO_RESP_CMD(ver) \
  85                SSIP_CMD(SSIP_BOOTINFO_RESP, SSIP_DATA_VERSION(ver))
  86#define SSIP_START_TRANS_CMD(pdulen, id) \
  87                SSIP_CMD(SSIP_START_TRANS, (((pdulen) << 8) | SSIP_MSG_ID(id)))
  88#define SSIP_READY_CMD          SSIP_CMD(SSIP_READY, 0)
  89#define SSIP_SWBREAK_CMD        SSIP_CMD(SSIP_SW_BREAK, 0)
  90
  91/* Main state machine states */
  92enum {
  93        INIT,
  94        HANDSHAKE,
  95        ACTIVE,
  96};
  97
  98/* Send state machine states */
  99enum {
 100        SEND_IDLE,
 101        WAIT4READY,
 102        SEND_READY,
 103        SENDING,
 104        SENDING_SWBREAK,
 105};
 106
 107/* Receive state machine states */
 108enum {
 109        RECV_IDLE,
 110        RECV_READY,
 111        RECEIVING,
 112};
 113
 114/**
 115 * struct ssi_protocol - SSI protocol (McSAAB) data
 116 * @main_state: Main state machine
 117 * @send_state: TX state machine
 118 * @recv_state: RX state machine
 119 * @waketest: Flag to follow wake line test
 120 * @rxid: RX data id
 121 * @txid: TX data id
 122 * @txqueue_len: TX queue length
 123 * @tx_wd: TX watchdog
 124 * @rx_wd: RX watchdog
 125 * @keep_alive: Workaround for SSI HW bug
 126 * @lock: To serialize access to this struct
 127 * @netdev: Phonet network device
 128 * @txqueue: TX data queue
 129 * @cmdqueue: Queue of free commands
 130 * @cl: HSI client own reference
 131 * @link: Link for ssip_list
 132 * @tx_usecount: Refcount to keep track the slaves that use the wake line
 133 * @channel_id_cmd: HSI channel id for command stream
 134 * @channel_id_data: HSI channel id for data stream
 135 */
 136struct ssi_protocol {
 137        unsigned int            main_state;
 138        unsigned int            send_state;
 139        unsigned int            recv_state;
 140        unsigned int            waketest:1;
 141        u8                      rxid;
 142        u8                      txid;
 143        unsigned int            txqueue_len;
 144        struct timer_list       tx_wd;
 145        struct timer_list       rx_wd;
 146        struct timer_list       keep_alive; /* wake-up workaround */
 147        spinlock_t              lock;
 148        struct net_device       *netdev;
 149        struct list_head        txqueue;
 150        struct list_head        cmdqueue;
 151        struct hsi_client       *cl;
 152        struct list_head        link;
 153        atomic_t                tx_usecnt;
 154        int                     channel_id_cmd;
 155        int                     channel_id_data;
 156};
 157
 158/* List of ssi protocol instances */
 159static LIST_HEAD(ssip_list);
 160
 161static void ssip_rxcmd_complete(struct hsi_msg *msg);
 162
 163static inline void ssip_set_cmd(struct hsi_msg *msg, u32 cmd)
 164{
 165        u32 *data;
 166
 167        data = sg_virt(msg->sgt.sgl);
 168        *data = cmd;
 169}
 170
 171static inline u32 ssip_get_cmd(struct hsi_msg *msg)
 172{
 173        u32 *data;
 174
 175        data = sg_virt(msg->sgt.sgl);
 176
 177        return *data;
 178}
 179
 180static void ssip_skb_to_msg(struct sk_buff *skb, struct hsi_msg *msg)
 181{
 182        skb_frag_t *frag;
 183        struct scatterlist *sg;
 184        int i;
 185
 186        BUG_ON(msg->sgt.nents != (unsigned int)(skb_shinfo(skb)->nr_frags + 1));
 187
 188        sg = msg->sgt.sgl;
 189        sg_set_buf(sg, skb->data, skb_headlen(skb));
 190        for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
 191                sg = sg_next(sg);
 192                BUG_ON(!sg);
 193                frag = &skb_shinfo(skb)->frags[i];
 194                sg_set_page(sg, frag->page.p, frag->size, frag->page_offset);
 195        }
 196}
 197
 198static void ssip_free_data(struct hsi_msg *msg)
 199{
 200        struct sk_buff *skb;
 201
 202        skb = msg->context;
 203        pr_debug("free data: msg %p context %p skb %p\n", msg, msg->context,
 204                                                                skb);
 205        msg->destructor = NULL;
 206        dev_kfree_skb(skb);
 207        hsi_free_msg(msg);
 208}
 209
 210static struct hsi_msg *ssip_alloc_data(struct ssi_protocol *ssi,
 211                                        struct sk_buff *skb, gfp_t flags)
 212{
 213        struct hsi_msg *msg;
 214
 215        msg = hsi_alloc_msg(skb_shinfo(skb)->nr_frags + 1, flags);
 216        if (!msg)
 217                return NULL;
 218        ssip_skb_to_msg(skb, msg);
 219        msg->destructor = ssip_free_data;
 220        msg->channel = ssi->channel_id_data;
 221        msg->context = skb;
 222
 223        return msg;
 224}
 225
 226static inline void ssip_release_cmd(struct hsi_msg *msg)
 227{
 228        struct ssi_protocol *ssi = hsi_client_drvdata(msg->cl);
 229
 230        dev_dbg(&msg->cl->device, "Release cmd 0x%08x\n", ssip_get_cmd(msg));
 231        spin_lock_bh(&ssi->lock);
 232        list_add_tail(&msg->link, &ssi->cmdqueue);
 233        spin_unlock_bh(&ssi->lock);
 234}
 235
 236static struct hsi_msg *ssip_claim_cmd(struct ssi_protocol *ssi)
 237{
 238        struct hsi_msg *msg;
 239
 240        BUG_ON(list_empty(&ssi->cmdqueue));
 241
 242        spin_lock_bh(&ssi->lock);
 243        msg = list_first_entry(&ssi->cmdqueue, struct hsi_msg, link);
 244        list_del(&msg->link);
 245        spin_unlock_bh(&ssi->lock);
 246        msg->destructor = ssip_release_cmd;
 247
 248        return msg;
 249}
 250
 251static void ssip_free_cmds(struct ssi_protocol *ssi)
 252{
 253        struct hsi_msg *msg, *tmp;
 254
 255        list_for_each_entry_safe(msg, tmp, &ssi->cmdqueue, link) {
 256                list_del(&msg->link);
 257                msg->destructor = NULL;
 258                kfree(sg_virt(msg->sgt.sgl));
 259                hsi_free_msg(msg);
 260        }
 261}
 262
 263static int ssip_alloc_cmds(struct ssi_protocol *ssi)
 264{
 265        struct hsi_msg *msg;
 266        u32 *buf;
 267        unsigned int i;
 268
 269        for (i = 0; i < SSIP_MAX_CMDS; i++) {
 270                msg = hsi_alloc_msg(1, GFP_KERNEL);
 271                if (!msg)
 272                        goto out;
 273                buf = kmalloc(sizeof(*buf), GFP_KERNEL);
 274                if (!buf) {
 275                        hsi_free_msg(msg);
 276                        goto out;
 277                }
 278                sg_init_one(msg->sgt.sgl, buf, sizeof(*buf));
 279                msg->channel = ssi->channel_id_cmd;
 280                list_add_tail(&msg->link, &ssi->cmdqueue);
 281        }
 282
 283        return 0;
 284out:
 285        ssip_free_cmds(ssi);
 286
 287        return -ENOMEM;
 288}
 289
 290static void ssip_set_rxstate(struct ssi_protocol *ssi, unsigned int state)
 291{
 292        ssi->recv_state = state;
 293        switch (state) {
 294        case RECV_IDLE:
 295                del_timer(&ssi->rx_wd);
 296                if (ssi->send_state == SEND_IDLE)
 297                        del_timer(&ssi->keep_alive);
 298                break;
 299        case RECV_READY:
 300                /* CMT speech workaround */
 301                if (atomic_read(&ssi->tx_usecnt))
 302                        break;
 303                /* Otherwise fall through */
 304        case RECEIVING:
 305                mod_timer(&ssi->keep_alive, jiffies +
 306                                                msecs_to_jiffies(SSIP_KATOUT));
 307                mod_timer(&ssi->rx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
 308                break;
 309        default:
 310                break;
 311        }
 312}
 313
 314static void ssip_set_txstate(struct ssi_protocol *ssi, unsigned int state)
 315{
 316        ssi->send_state = state;
 317        switch (state) {
 318        case SEND_IDLE:
 319        case SEND_READY:
 320                del_timer(&ssi->tx_wd);
 321                if (ssi->recv_state == RECV_IDLE)
 322                        del_timer(&ssi->keep_alive);
 323                break;
 324        case WAIT4READY:
 325        case SENDING:
 326        case SENDING_SWBREAK:
 327                mod_timer(&ssi->keep_alive,
 328                                jiffies + msecs_to_jiffies(SSIP_KATOUT));
 329                mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
 330                break;
 331        default:
 332                break;
 333        }
 334}
 335
 336struct hsi_client *ssip_slave_get_master(struct hsi_client *slave)
 337{
 338        struct hsi_client *master = ERR_PTR(-ENODEV);
 339        struct ssi_protocol *ssi;
 340
 341        list_for_each_entry(ssi, &ssip_list, link)
 342                if (slave->device.parent == ssi->cl->device.parent) {
 343                        master = ssi->cl;
 344                        break;
 345                }
 346
 347        return master;
 348}
 349EXPORT_SYMBOL_GPL(ssip_slave_get_master);
 350
 351int ssip_slave_start_tx(struct hsi_client *master)
 352{
 353        struct ssi_protocol *ssi = hsi_client_drvdata(master);
 354
 355        dev_dbg(&master->device, "start TX %d\n", atomic_read(&ssi->tx_usecnt));
 356        spin_lock_bh(&ssi->lock);
 357        if (ssi->send_state == SEND_IDLE) {
 358                ssip_set_txstate(ssi, WAIT4READY);
 359                hsi_start_tx(master);
 360        }
 361        spin_unlock_bh(&ssi->lock);
 362        atomic_inc(&ssi->tx_usecnt);
 363
 364        return 0;
 365}
 366EXPORT_SYMBOL_GPL(ssip_slave_start_tx);
 367
 368int ssip_slave_stop_tx(struct hsi_client *master)
 369{
 370        struct ssi_protocol *ssi = hsi_client_drvdata(master);
 371
 372        WARN_ON_ONCE(atomic_read(&ssi->tx_usecnt) == 0);
 373
 374        if (atomic_dec_and_test(&ssi->tx_usecnt)) {
 375                spin_lock_bh(&ssi->lock);
 376                if ((ssi->send_state == SEND_READY) ||
 377                        (ssi->send_state == WAIT4READY)) {
 378                        ssip_set_txstate(ssi, SEND_IDLE);
 379                        hsi_stop_tx(master);
 380                }
 381                spin_unlock_bh(&ssi->lock);
 382        }
 383        dev_dbg(&master->device, "stop TX %d\n", atomic_read(&ssi->tx_usecnt));
 384
 385        return 0;
 386}
 387EXPORT_SYMBOL_GPL(ssip_slave_stop_tx);
 388
 389int ssip_slave_running(struct hsi_client *master)
 390{
 391        struct ssi_protocol *ssi = hsi_client_drvdata(master);
 392        return netif_running(ssi->netdev);
 393}
 394EXPORT_SYMBOL_GPL(ssip_slave_running);
 395
 396static void ssip_reset(struct hsi_client *cl)
 397{
 398        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 399        struct list_head *head, *tmp;
 400        struct hsi_msg *msg;
 401
 402        if (netif_running(ssi->netdev))
 403                netif_carrier_off(ssi->netdev);
 404        hsi_flush(cl);
 405        spin_lock_bh(&ssi->lock);
 406        if (ssi->send_state != SEND_IDLE)
 407                hsi_stop_tx(cl);
 408        if (ssi->waketest)
 409                ssi_waketest(cl, 0);
 410        del_timer(&ssi->rx_wd);
 411        del_timer(&ssi->tx_wd);
 412        del_timer(&ssi->keep_alive);
 413        ssi->main_state = 0;
 414        ssi->send_state = 0;
 415        ssi->recv_state = 0;
 416        ssi->waketest = 0;
 417        ssi->rxid = 0;
 418        ssi->txid = 0;
 419        list_for_each_safe(head, tmp, &ssi->txqueue) {
 420                msg = list_entry(head, struct hsi_msg, link);
 421                dev_dbg(&cl->device, "Pending TX data\n");
 422                list_del(head);
 423                ssip_free_data(msg);
 424        }
 425        ssi->txqueue_len = 0;
 426        spin_unlock_bh(&ssi->lock);
 427}
 428
 429static void ssip_dump_state(struct hsi_client *cl)
 430{
 431        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 432        struct hsi_msg *msg;
 433
 434        spin_lock_bh(&ssi->lock);
 435        dev_err(&cl->device, "Main state: %d\n", ssi->main_state);
 436        dev_err(&cl->device, "Recv state: %d\n", ssi->recv_state);
 437        dev_err(&cl->device, "Send state: %d\n", ssi->send_state);
 438        dev_err(&cl->device, "CMT %s\n", (ssi->main_state == ACTIVE) ?
 439                                                        "Online" : "Offline");
 440        dev_err(&cl->device, "Wake test %d\n", ssi->waketest);
 441        dev_err(&cl->device, "Data RX id: %d\n", ssi->rxid);
 442        dev_err(&cl->device, "Data TX id: %d\n", ssi->txid);
 443
 444        list_for_each_entry(msg, &ssi->txqueue, link)
 445                dev_err(&cl->device, "pending TX data (%p)\n", msg);
 446        spin_unlock_bh(&ssi->lock);
 447}
 448
 449static void ssip_error(struct hsi_client *cl)
 450{
 451        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 452        struct hsi_msg *msg;
 453
 454        ssip_dump_state(cl);
 455        ssip_reset(cl);
 456        msg = ssip_claim_cmd(ssi);
 457        msg->complete = ssip_rxcmd_complete;
 458        hsi_async_read(cl, msg);
 459}
 460
 461static void ssip_keep_alive(unsigned long data)
 462{
 463        struct hsi_client *cl = (struct hsi_client *)data;
 464        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 465
 466        dev_dbg(&cl->device, "Keep alive kick in: m(%d) r(%d) s(%d)\n",
 467                ssi->main_state, ssi->recv_state, ssi->send_state);
 468
 469        spin_lock(&ssi->lock);
 470        if (ssi->recv_state == RECV_IDLE)
 471                switch (ssi->send_state) {
 472                case SEND_READY:
 473                        if (atomic_read(&ssi->tx_usecnt) == 0)
 474                                break;
 475                        /*
 476                         * Fall through. Workaround for cmt-speech
 477                         * in that case we relay on audio timers.
 478                         */
 479                case SEND_IDLE:
 480                        spin_unlock(&ssi->lock);
 481                        return;
 482                }
 483        mod_timer(&ssi->keep_alive, jiffies + msecs_to_jiffies(SSIP_KATOUT));
 484        spin_unlock(&ssi->lock);
 485}
 486
 487static void ssip_wd(unsigned long data)
 488{
 489        struct hsi_client *cl = (struct hsi_client *)data;
 490
 491        dev_err(&cl->device, "Watchdog trigerred\n");
 492        ssip_error(cl);
 493}
 494
 495static void ssip_send_bootinfo_req_cmd(struct hsi_client *cl)
 496{
 497        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 498        struct hsi_msg *msg;
 499
 500        dev_dbg(&cl->device, "Issuing BOOT INFO REQ command\n");
 501        msg = ssip_claim_cmd(ssi);
 502        ssip_set_cmd(msg, SSIP_BOOTINFO_REQ_CMD(SSIP_LOCAL_VERID));
 503        msg->complete = ssip_release_cmd;
 504        hsi_async_write(cl, msg);
 505        dev_dbg(&cl->device, "Issuing RX command\n");
 506        msg = ssip_claim_cmd(ssi);
 507        msg->complete = ssip_rxcmd_complete;
 508        hsi_async_read(cl, msg);
 509}
 510
 511static void ssip_start_rx(struct hsi_client *cl)
 512{
 513        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 514        struct hsi_msg *msg;
 515
 516        dev_dbg(&cl->device, "RX start M(%d) R(%d)\n", ssi->main_state,
 517                                                ssi->recv_state);
 518        spin_lock(&ssi->lock);
 519        /*
 520         * We can have two UP events in a row due to a short low
 521         * high transition. Therefore we need to ignore the sencond UP event.
 522         */
 523        if ((ssi->main_state != ACTIVE) || (ssi->recv_state == RECV_READY)) {
 524                spin_unlock(&ssi->lock);
 525                return;
 526        }
 527        ssip_set_rxstate(ssi, RECV_READY);
 528        spin_unlock(&ssi->lock);
 529
 530        msg = ssip_claim_cmd(ssi);
 531        ssip_set_cmd(msg, SSIP_READY_CMD);
 532        msg->complete = ssip_release_cmd;
 533        dev_dbg(&cl->device, "Send READY\n");
 534        hsi_async_write(cl, msg);
 535}
 536
 537static void ssip_stop_rx(struct hsi_client *cl)
 538{
 539        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 540
 541        dev_dbg(&cl->device, "RX stop M(%d)\n", ssi->main_state);
 542        spin_lock(&ssi->lock);
 543        if (likely(ssi->main_state == ACTIVE))
 544                ssip_set_rxstate(ssi, RECV_IDLE);
 545        spin_unlock(&ssi->lock);
 546}
 547
 548static void ssip_free_strans(struct hsi_msg *msg)
 549{
 550        ssip_free_data(msg->context);
 551        ssip_release_cmd(msg);
 552}
 553
 554static void ssip_strans_complete(struct hsi_msg *msg)
 555{
 556        struct hsi_client *cl = msg->cl;
 557        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 558        struct hsi_msg *data;
 559
 560        data = msg->context;
 561        ssip_release_cmd(msg);
 562        spin_lock(&ssi->lock);
 563        ssip_set_txstate(ssi, SENDING);
 564        spin_unlock(&ssi->lock);
 565        hsi_async_write(cl, data);
 566}
 567
 568static int ssip_xmit(struct hsi_client *cl)
 569{
 570        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 571        struct hsi_msg *msg, *dmsg;
 572        struct sk_buff *skb;
 573
 574        spin_lock_bh(&ssi->lock);
 575        if (list_empty(&ssi->txqueue)) {
 576                spin_unlock_bh(&ssi->lock);
 577                return 0;
 578        }
 579        dmsg = list_first_entry(&ssi->txqueue, struct hsi_msg, link);
 580        list_del(&dmsg->link);
 581        ssi->txqueue_len--;
 582        spin_unlock_bh(&ssi->lock);
 583
 584        msg = ssip_claim_cmd(ssi);
 585        skb = dmsg->context;
 586        msg->context = dmsg;
 587        msg->complete = ssip_strans_complete;
 588        msg->destructor = ssip_free_strans;
 589
 590        spin_lock_bh(&ssi->lock);
 591        ssip_set_cmd(msg, SSIP_START_TRANS_CMD(SSIP_BYTES_TO_FRAMES(skb->len),
 592                                                                ssi->txid));
 593        ssi->txid++;
 594        ssip_set_txstate(ssi, SENDING);
 595        spin_unlock_bh(&ssi->lock);
 596
 597        dev_dbg(&cl->device, "Send STRANS (%d frames)\n",
 598                                                SSIP_BYTES_TO_FRAMES(skb->len));
 599
 600        return hsi_async_write(cl, msg);
 601}
 602
 603/* In soft IRQ context */
 604static void ssip_pn_rx(struct sk_buff *skb)
 605{
 606        struct net_device *dev = skb->dev;
 607
 608        if (unlikely(!netif_running(dev))) {
 609                dev_dbg(&dev->dev, "Drop RX packet\n");
 610                dev->stats.rx_dropped++;
 611                dev_kfree_skb(skb);
 612                return;
 613        }
 614        if (unlikely(!pskb_may_pull(skb, SSIP_MIN_PN_HDR))) {
 615                dev_dbg(&dev->dev, "Error drop RX packet\n");
 616                dev->stats.rx_errors++;
 617                dev->stats.rx_length_errors++;
 618                dev_kfree_skb(skb);
 619                return;
 620        }
 621        dev->stats.rx_packets++;
 622        dev->stats.rx_bytes += skb->len;
 623
 624        /* length field is exchanged in network byte order */
 625        ((u16 *)skb->data)[2] = ntohs(((u16 *)skb->data)[2]);
 626        dev_dbg(&dev->dev, "RX length fixed (%04x -> %u)\n",
 627                        ((u16 *)skb->data)[2], ntohs(((u16 *)skb->data)[2]));
 628
 629        skb->protocol = htons(ETH_P_PHONET);
 630        skb_reset_mac_header(skb);
 631        __skb_pull(skb, 1);
 632        netif_rx(skb);
 633}
 634
 635static void ssip_rx_data_complete(struct hsi_msg *msg)
 636{
 637        struct hsi_client *cl = msg->cl;
 638        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 639        struct sk_buff *skb;
 640
 641        if (msg->status == HSI_STATUS_ERROR) {
 642                dev_err(&cl->device, "RX data error\n");
 643                ssip_free_data(msg);
 644                ssip_error(cl);
 645                return;
 646        }
 647        del_timer(&ssi->rx_wd); /* FIXME: Revisit */
 648        skb = msg->context;
 649        ssip_pn_rx(skb);
 650        hsi_free_msg(msg);
 651}
 652
 653static void ssip_rx_bootinforeq(struct hsi_client *cl, u32 cmd)
 654{
 655        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 656        struct hsi_msg *msg;
 657
 658        /* Workaroud: Ignore CMT Loader message leftover */
 659        if (cmd == SSIP_CMT_LOADER_SYNC)
 660                return;
 661
 662        switch (ssi->main_state) {
 663        case ACTIVE:
 664                dev_err(&cl->device, "Boot info req on active state\n");
 665                ssip_error(cl);
 666                /* Fall through */
 667        case INIT:
 668        case HANDSHAKE:
 669                spin_lock(&ssi->lock);
 670                ssi->main_state = HANDSHAKE;
 671                if (!ssi->waketest) {
 672                        ssi->waketest = 1;
 673                        ssi_waketest(cl, 1); /* FIXME: To be removed */
 674                }
 675                /* Start boot handshake watchdog */
 676                mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
 677                spin_unlock(&ssi->lock);
 678                dev_dbg(&cl->device, "Send BOOTINFO_RESP\n");
 679                if (SSIP_DATA_VERSION(cmd) != SSIP_LOCAL_VERID)
 680                        dev_warn(&cl->device, "boot info req verid mismatch\n");
 681                msg = ssip_claim_cmd(ssi);
 682                ssip_set_cmd(msg, SSIP_BOOTINFO_RESP_CMD(SSIP_LOCAL_VERID));
 683                msg->complete = ssip_release_cmd;
 684                hsi_async_write(cl, msg);
 685                break;
 686        default:
 687                dev_dbg(&cl->device, "Wrong state M(%d)\n", ssi->main_state);
 688                break;
 689        }
 690}
 691
 692static void ssip_rx_bootinforesp(struct hsi_client *cl, u32 cmd)
 693{
 694        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 695
 696        if (SSIP_DATA_VERSION(cmd) != SSIP_LOCAL_VERID)
 697                dev_warn(&cl->device, "boot info resp verid mismatch\n");
 698
 699        spin_lock(&ssi->lock);
 700        if (ssi->main_state != ACTIVE)
 701                /* Use tx_wd as a boot watchdog in non ACTIVE state */
 702                mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
 703        else
 704                dev_dbg(&cl->device, "boot info resp ignored M(%d)\n",
 705                                                        ssi->main_state);
 706        spin_unlock(&ssi->lock);
 707}
 708
 709static void ssip_rx_waketest(struct hsi_client *cl, u32 cmd)
 710{
 711        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 712        unsigned int wkres = SSIP_PAYLOAD(cmd);
 713
 714        spin_lock(&ssi->lock);
 715        if (ssi->main_state != HANDSHAKE) {
 716                dev_dbg(&cl->device, "wake lines test ignored M(%d)\n",
 717                                                        ssi->main_state);
 718                spin_unlock(&ssi->lock);
 719                return;
 720        }
 721        if (ssi->waketest) {
 722                ssi->waketest = 0;
 723                ssi_waketest(cl, 0); /* FIXME: To be removed */
 724        }
 725        ssi->main_state = ACTIVE;
 726        del_timer(&ssi->tx_wd); /* Stop boot handshake timer */
 727        spin_unlock(&ssi->lock);
 728
 729        dev_notice(&cl->device, "WAKELINES TEST %s\n",
 730                                wkres & SSIP_WAKETEST_FAILED ? "FAILED" : "OK");
 731        if (wkres & SSIP_WAKETEST_FAILED) {
 732                ssip_error(cl);
 733                return;
 734        }
 735        dev_dbg(&cl->device, "CMT is ONLINE\n");
 736        netif_wake_queue(ssi->netdev);
 737        netif_carrier_on(ssi->netdev);
 738}
 739
 740static void ssip_rx_ready(struct hsi_client *cl)
 741{
 742        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 743
 744        spin_lock(&ssi->lock);
 745        if (unlikely(ssi->main_state != ACTIVE)) {
 746                dev_dbg(&cl->device, "READY on wrong state: S(%d) M(%d)\n",
 747                                        ssi->send_state, ssi->main_state);
 748                spin_unlock(&ssi->lock);
 749                return;
 750        }
 751        if (ssi->send_state != WAIT4READY) {
 752                dev_dbg(&cl->device, "Ignore spurious READY command\n");
 753                spin_unlock(&ssi->lock);
 754                return;
 755        }
 756        ssip_set_txstate(ssi, SEND_READY);
 757        spin_unlock(&ssi->lock);
 758        ssip_xmit(cl);
 759}
 760
 761static void ssip_rx_strans(struct hsi_client *cl, u32 cmd)
 762{
 763        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 764        struct sk_buff *skb;
 765        struct hsi_msg *msg;
 766        int len = SSIP_PDU_LENGTH(cmd);
 767
 768        dev_dbg(&cl->device, "RX strans: %d frames\n", len);
 769        spin_lock(&ssi->lock);
 770        if (unlikely(ssi->main_state != ACTIVE)) {
 771                dev_err(&cl->device, "START TRANS wrong state: S(%d) M(%d)\n",
 772                                        ssi->send_state, ssi->main_state);
 773                spin_unlock(&ssi->lock);
 774                return;
 775        }
 776        ssip_set_rxstate(ssi, RECEIVING);
 777        if (unlikely(SSIP_MSG_ID(cmd) != ssi->rxid)) {
 778                dev_err(&cl->device, "START TRANS id %d expected %d\n",
 779                                        SSIP_MSG_ID(cmd), ssi->rxid);
 780                spin_unlock(&ssi->lock);
 781                goto out1;
 782        }
 783        ssi->rxid++;
 784        spin_unlock(&ssi->lock);
 785        skb = netdev_alloc_skb(ssi->netdev, len * 4);
 786        if (unlikely(!skb)) {
 787                dev_err(&cl->device, "No memory for rx skb\n");
 788                goto out1;
 789        }
 790        skb->dev = ssi->netdev;
 791        skb_put(skb, len * 4);
 792        msg = ssip_alloc_data(ssi, skb, GFP_ATOMIC);
 793        if (unlikely(!msg)) {
 794                dev_err(&cl->device, "No memory for RX data msg\n");
 795                goto out2;
 796        }
 797        msg->complete = ssip_rx_data_complete;
 798        hsi_async_read(cl, msg);
 799
 800        return;
 801out2:
 802        dev_kfree_skb(skb);
 803out1:
 804        ssip_error(cl);
 805}
 806
 807static void ssip_rxcmd_complete(struct hsi_msg *msg)
 808{
 809        struct hsi_client *cl = msg->cl;
 810        u32 cmd = ssip_get_cmd(msg);
 811        unsigned int cmdid = SSIP_COMMAND(cmd);
 812
 813        if (msg->status == HSI_STATUS_ERROR) {
 814                dev_err(&cl->device, "RX error detected\n");
 815                ssip_release_cmd(msg);
 816                ssip_error(cl);
 817                return;
 818        }
 819        hsi_async_read(cl, msg);
 820        dev_dbg(&cl->device, "RX cmd: 0x%08x\n", cmd);
 821        switch (cmdid) {
 822        case SSIP_SW_BREAK:
 823                /* Ignored */
 824                break;
 825        case SSIP_BOOTINFO_REQ:
 826                ssip_rx_bootinforeq(cl, cmd);
 827                break;
 828        case SSIP_BOOTINFO_RESP:
 829                ssip_rx_bootinforesp(cl, cmd);
 830                break;
 831        case SSIP_WAKETEST_RESULT:
 832                ssip_rx_waketest(cl, cmd);
 833                break;
 834        case SSIP_START_TRANS:
 835                ssip_rx_strans(cl, cmd);
 836                break;
 837        case SSIP_READY:
 838                ssip_rx_ready(cl);
 839                break;
 840        default:
 841                dev_warn(&cl->device, "command 0x%08x not supported\n", cmd);
 842                break;
 843        }
 844}
 845
 846static void ssip_swbreak_complete(struct hsi_msg *msg)
 847{
 848        struct hsi_client *cl = msg->cl;
 849        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 850
 851        ssip_release_cmd(msg);
 852        spin_lock(&ssi->lock);
 853        if (list_empty(&ssi->txqueue)) {
 854                if (atomic_read(&ssi->tx_usecnt)) {
 855                        ssip_set_txstate(ssi, SEND_READY);
 856                } else {
 857                        ssip_set_txstate(ssi, SEND_IDLE);
 858                        hsi_stop_tx(cl);
 859                }
 860                spin_unlock(&ssi->lock);
 861        } else {
 862                spin_unlock(&ssi->lock);
 863                ssip_xmit(cl);
 864        }
 865        netif_wake_queue(ssi->netdev);
 866}
 867
 868static void ssip_tx_data_complete(struct hsi_msg *msg)
 869{
 870        struct hsi_client *cl = msg->cl;
 871        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 872        struct hsi_msg *cmsg;
 873
 874        if (msg->status == HSI_STATUS_ERROR) {
 875                dev_err(&cl->device, "TX data error\n");
 876                ssip_error(cl);
 877                goto out;
 878        }
 879        spin_lock(&ssi->lock);
 880        if (list_empty(&ssi->txqueue)) {
 881                ssip_set_txstate(ssi, SENDING_SWBREAK);
 882                spin_unlock(&ssi->lock);
 883                cmsg = ssip_claim_cmd(ssi);
 884                ssip_set_cmd(cmsg, SSIP_SWBREAK_CMD);
 885                cmsg->complete = ssip_swbreak_complete;
 886                dev_dbg(&cl->device, "Send SWBREAK\n");
 887                hsi_async_write(cl, cmsg);
 888        } else {
 889                spin_unlock(&ssi->lock);
 890                ssip_xmit(cl);
 891        }
 892out:
 893        ssip_free_data(msg);
 894}
 895
 896static void ssip_port_event(struct hsi_client *cl, unsigned long event)
 897{
 898        switch (event) {
 899        case HSI_EVENT_START_RX:
 900                ssip_start_rx(cl);
 901                break;
 902        case HSI_EVENT_STOP_RX:
 903                ssip_stop_rx(cl);
 904                break;
 905        default:
 906                return;
 907        }
 908}
 909
 910static int ssip_pn_open(struct net_device *dev)
 911{
 912        struct hsi_client *cl = to_hsi_client(dev->dev.parent);
 913        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 914        int err;
 915
 916        err = hsi_claim_port(cl, 1);
 917        if (err < 0) {
 918                dev_err(&cl->device, "SSI port already claimed\n");
 919                return err;
 920        }
 921        err = hsi_register_port_event(cl, ssip_port_event);
 922        if (err < 0) {
 923                dev_err(&cl->device, "Register HSI port event failed (%d)\n",
 924                        err);
 925                return err;
 926        }
 927        dev_dbg(&cl->device, "Configuring SSI port\n");
 928        hsi_setup(cl);
 929        spin_lock_bh(&ssi->lock);
 930        if (!ssi->waketest) {
 931                ssi->waketest = 1;
 932                ssi_waketest(cl, 1); /* FIXME: To be removed */
 933        }
 934        ssi->main_state = HANDSHAKE;
 935        spin_unlock_bh(&ssi->lock);
 936
 937        ssip_send_bootinfo_req_cmd(cl);
 938
 939        return 0;
 940}
 941
 942static int ssip_pn_stop(struct net_device *dev)
 943{
 944        struct hsi_client *cl = to_hsi_client(dev->dev.parent);
 945
 946        ssip_reset(cl);
 947        hsi_unregister_port_event(cl);
 948        hsi_release_port(cl);
 949
 950        return 0;
 951}
 952
 953static int ssip_pn_set_mtu(struct net_device *dev, int new_mtu)
 954{
 955        if (new_mtu > SSIP_MAX_MTU || new_mtu < PHONET_MIN_MTU)
 956                return -EINVAL;
 957        dev->mtu = new_mtu;
 958
 959        return 0;
 960}
 961
 962static int ssip_pn_xmit(struct sk_buff *skb, struct net_device *dev)
 963{
 964        struct hsi_client *cl = to_hsi_client(dev->dev.parent);
 965        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 966        struct hsi_msg *msg;
 967
 968        if ((skb->protocol != htons(ETH_P_PHONET)) ||
 969                                        (skb->len < SSIP_MIN_PN_HDR))
 970                goto drop;
 971        /* Pad to 32-bits - FIXME: Revisit*/
 972        if ((skb->len & 3) && skb_pad(skb, 4 - (skb->len & 3)))
 973                goto drop;
 974
 975        /*
 976         * Modem sends Phonet messages over SSI with its own endianess...
 977         * Assume that modem has the same endianess as we do.
 978         */
 979        if (skb_cow_head(skb, 0))
 980                goto drop;
 981
 982        /* length field is exchanged in network byte order */
 983        ((u16 *)skb->data)[2] = htons(((u16 *)skb->data)[2]);
 984
 985        msg = ssip_alloc_data(ssi, skb, GFP_ATOMIC);
 986        if (!msg) {
 987                dev_dbg(&cl->device, "Dropping tx data: No memory\n");
 988                goto drop;
 989        }
 990        msg->complete = ssip_tx_data_complete;
 991
 992        spin_lock_bh(&ssi->lock);
 993        if (unlikely(ssi->main_state != ACTIVE)) {
 994                spin_unlock_bh(&ssi->lock);
 995                dev_dbg(&cl->device, "Dropping tx data: CMT is OFFLINE\n");
 996                goto drop2;
 997        }
 998        list_add_tail(&msg->link, &ssi->txqueue);
 999        ssi->txqueue_len++;
1000        if (dev->tx_queue_len < ssi->txqueue_len) {
1001                dev_info(&cl->device, "TX queue full %d\n", ssi->txqueue_len);
1002                netif_stop_queue(dev);
1003        }
1004        if (ssi->send_state == SEND_IDLE) {
1005                ssip_set_txstate(ssi, WAIT4READY);
1006                spin_unlock_bh(&ssi->lock);
1007                dev_dbg(&cl->device, "Start TX qlen %d\n", ssi->txqueue_len);
1008                hsi_start_tx(cl);
1009        } else if (ssi->send_state == SEND_READY) {
1010                /* Needed for cmt-speech workaround */
1011                dev_dbg(&cl->device, "Start TX on SEND READY qlen %d\n",
1012                                                        ssi->txqueue_len);
1013                spin_unlock_bh(&ssi->lock);
1014                ssip_xmit(cl);
1015        } else {
1016                spin_unlock_bh(&ssi->lock);
1017        }
1018        dev->stats.tx_packets++;
1019        dev->stats.tx_bytes += skb->len;
1020
1021        return 0;
1022drop2:
1023        hsi_free_msg(msg);
1024drop:
1025        dev->stats.tx_dropped++;
1026        dev_kfree_skb(skb);
1027
1028        return 0;
1029}
1030
1031/* CMT reset event handler */
1032void ssip_reset_event(struct hsi_client *master)
1033{
1034        struct ssi_protocol *ssi = hsi_client_drvdata(master);
1035        dev_err(&ssi->cl->device, "CMT reset detected!\n");
1036        ssip_error(ssi->cl);
1037}
1038EXPORT_SYMBOL_GPL(ssip_reset_event);
1039
1040static const struct net_device_ops ssip_pn_ops = {
1041        .ndo_open       = ssip_pn_open,
1042        .ndo_stop       = ssip_pn_stop,
1043        .ndo_start_xmit = ssip_pn_xmit,
1044        .ndo_change_mtu = ssip_pn_set_mtu,
1045};
1046
1047static void ssip_pn_setup(struct net_device *dev)
1048{
1049        dev->features           = 0;
1050        dev->netdev_ops         = &ssip_pn_ops;
1051        dev->type               = ARPHRD_PHONET;
1052        dev->flags              = IFF_POINTOPOINT | IFF_NOARP;
1053        dev->mtu                = SSIP_DEFAULT_MTU;
1054        dev->hard_header_len    = 1;
1055        dev->dev_addr[0]        = PN_MEDIA_SOS;
1056        dev->addr_len           = 1;
1057        dev->tx_queue_len       = SSIP_TXQUEUE_LEN;
1058
1059        dev->destructor         = free_netdev;
1060        dev->header_ops         = &phonet_header_ops;
1061}
1062
1063static int ssi_protocol_probe(struct device *dev)
1064{
1065        static const char ifname[] = "phonet%d";
1066        struct hsi_client *cl = to_hsi_client(dev);
1067        struct ssi_protocol *ssi;
1068        int err;
1069
1070        ssi = kzalloc(sizeof(*ssi), GFP_KERNEL);
1071        if (!ssi) {
1072                dev_err(dev, "No memory for ssi protocol\n");
1073                return -ENOMEM;
1074        }
1075
1076        spin_lock_init(&ssi->lock);
1077        init_timer_deferrable(&ssi->rx_wd);
1078        init_timer_deferrable(&ssi->tx_wd);
1079        init_timer(&ssi->keep_alive);
1080        ssi->rx_wd.data = (unsigned long)cl;
1081        ssi->rx_wd.function = ssip_wd;
1082        ssi->tx_wd.data = (unsigned long)cl;
1083        ssi->tx_wd.function = ssip_wd;
1084        ssi->keep_alive.data = (unsigned long)cl;
1085        ssi->keep_alive.function = ssip_keep_alive;
1086        INIT_LIST_HEAD(&ssi->txqueue);
1087        INIT_LIST_HEAD(&ssi->cmdqueue);
1088        atomic_set(&ssi->tx_usecnt, 0);
1089        hsi_client_set_drvdata(cl, ssi);
1090        ssi->cl = cl;
1091
1092        ssi->channel_id_cmd = hsi_get_channel_id_by_name(cl, "mcsaab-control");
1093        if (ssi->channel_id_cmd < 0) {
1094                err = ssi->channel_id_cmd;
1095                dev_err(dev, "Could not get cmd channel (%d)\n", err);
1096                goto out;
1097        }
1098
1099        ssi->channel_id_data = hsi_get_channel_id_by_name(cl, "mcsaab-data");
1100        if (ssi->channel_id_data < 0) {
1101                err = ssi->channel_id_data;
1102                dev_err(dev, "Could not get data channel (%d)\n", err);
1103                goto out;
1104        }
1105
1106        err = ssip_alloc_cmds(ssi);
1107        if (err < 0) {
1108                dev_err(dev, "No memory for commands\n");
1109                goto out;
1110        }
1111
1112        ssi->netdev = alloc_netdev(0, ifname, NET_NAME_UNKNOWN, ssip_pn_setup);
1113        if (!ssi->netdev) {
1114                dev_err(dev, "No memory for netdev\n");
1115                err = -ENOMEM;
1116                goto out1;
1117        }
1118
1119        SET_NETDEV_DEV(ssi->netdev, dev);
1120        netif_carrier_off(ssi->netdev);
1121        err = register_netdev(ssi->netdev);
1122        if (err < 0) {
1123                dev_err(dev, "Register netdev failed (%d)\n", err);
1124                goto out2;
1125        }
1126
1127        list_add(&ssi->link, &ssip_list);
1128
1129        dev_dbg(dev, "channel configuration: cmd=%d, data=%d\n",
1130                ssi->channel_id_cmd, ssi->channel_id_data);
1131
1132        return 0;
1133out2:
1134        free_netdev(ssi->netdev);
1135out1:
1136        ssip_free_cmds(ssi);
1137out:
1138        kfree(ssi);
1139
1140        return err;
1141}
1142
1143static int ssi_protocol_remove(struct device *dev)
1144{
1145        struct hsi_client *cl = to_hsi_client(dev);
1146        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
1147
1148        list_del(&ssi->link);
1149        unregister_netdev(ssi->netdev);
1150        ssip_free_cmds(ssi);
1151        hsi_client_set_drvdata(cl, NULL);
1152        kfree(ssi);
1153
1154        return 0;
1155}
1156
1157static struct hsi_client_driver ssip_driver = {
1158        .driver = {
1159                .name   = "ssi-protocol",
1160                .owner  = THIS_MODULE,
1161                .probe  = ssi_protocol_probe,
1162                .remove = ssi_protocol_remove,
1163        },
1164};
1165
1166static int __init ssip_init(void)
1167{
1168        pr_info("SSI protocol aka McSAAB added\n");
1169
1170        return hsi_register_client_driver(&ssip_driver);
1171}
1172module_init(ssip_init);
1173
1174static void __exit ssip_exit(void)
1175{
1176        hsi_unregister_client_driver(&ssip_driver);
1177        pr_info("SSI protocol driver removed\n");
1178}
1179module_exit(ssip_exit);
1180
1181MODULE_ALIAS("hsi:ssi-protocol");
1182MODULE_AUTHOR("Carlos Chinea <carlos.chinea@nokia.com>");
1183MODULE_AUTHOR("Remi Denis-Courmont <remi.denis-courmont@nokia.com>");
1184MODULE_DESCRIPTION("SSI protocol improved aka McSAAB");
1185MODULE_LICENSE("GPL");
1186