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                if (ssi->main_state == INIT) {
 525                        ssi->main_state = HANDSHAKE;
 526                        spin_unlock(&ssi->lock);
 527                        ssip_send_bootinfo_req_cmd(cl);
 528                } else {
 529                        spin_unlock(&ssi->lock);
 530                }
 531                return;
 532        }
 533        ssip_set_rxstate(ssi, RECV_READY);
 534        spin_unlock(&ssi->lock);
 535
 536        msg = ssip_claim_cmd(ssi);
 537        ssip_set_cmd(msg, SSIP_READY_CMD);
 538        msg->complete = ssip_release_cmd;
 539        dev_dbg(&cl->device, "Send READY\n");
 540        hsi_async_write(cl, msg);
 541}
 542
 543static void ssip_stop_rx(struct hsi_client *cl)
 544{
 545        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 546
 547        dev_dbg(&cl->device, "RX stop M(%d)\n", ssi->main_state);
 548        spin_lock(&ssi->lock);
 549        if (likely(ssi->main_state == ACTIVE))
 550                ssip_set_rxstate(ssi, RECV_IDLE);
 551        spin_unlock(&ssi->lock);
 552}
 553
 554static void ssip_free_strans(struct hsi_msg *msg)
 555{
 556        ssip_free_data(msg->context);
 557        ssip_release_cmd(msg);
 558}
 559
 560static void ssip_strans_complete(struct hsi_msg *msg)
 561{
 562        struct hsi_client *cl = msg->cl;
 563        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 564        struct hsi_msg *data;
 565
 566        data = msg->context;
 567        ssip_release_cmd(msg);
 568        spin_lock(&ssi->lock);
 569        ssip_set_txstate(ssi, SENDING);
 570        spin_unlock(&ssi->lock);
 571        hsi_async_write(cl, data);
 572}
 573
 574static int ssip_xmit(struct hsi_client *cl)
 575{
 576        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 577        struct hsi_msg *msg, *dmsg;
 578        struct sk_buff *skb;
 579
 580        spin_lock_bh(&ssi->lock);
 581        if (list_empty(&ssi->txqueue)) {
 582                spin_unlock_bh(&ssi->lock);
 583                return 0;
 584        }
 585        dmsg = list_first_entry(&ssi->txqueue, struct hsi_msg, link);
 586        list_del(&dmsg->link);
 587        ssi->txqueue_len--;
 588        spin_unlock_bh(&ssi->lock);
 589
 590        msg = ssip_claim_cmd(ssi);
 591        skb = dmsg->context;
 592        msg->context = dmsg;
 593        msg->complete = ssip_strans_complete;
 594        msg->destructor = ssip_free_strans;
 595
 596        spin_lock_bh(&ssi->lock);
 597        ssip_set_cmd(msg, SSIP_START_TRANS_CMD(SSIP_BYTES_TO_FRAMES(skb->len),
 598                                                                ssi->txid));
 599        ssi->txid++;
 600        ssip_set_txstate(ssi, SENDING);
 601        spin_unlock_bh(&ssi->lock);
 602
 603        dev_dbg(&cl->device, "Send STRANS (%d frames)\n",
 604                                                SSIP_BYTES_TO_FRAMES(skb->len));
 605
 606        return hsi_async_write(cl, msg);
 607}
 608
 609/* In soft IRQ context */
 610static void ssip_pn_rx(struct sk_buff *skb)
 611{
 612        struct net_device *dev = skb->dev;
 613
 614        if (unlikely(!netif_running(dev))) {
 615                dev_dbg(&dev->dev, "Drop RX packet\n");
 616                dev->stats.rx_dropped++;
 617                dev_kfree_skb(skb);
 618                return;
 619        }
 620        if (unlikely(!pskb_may_pull(skb, SSIP_MIN_PN_HDR))) {
 621                dev_dbg(&dev->dev, "Error drop RX packet\n");
 622                dev->stats.rx_errors++;
 623                dev->stats.rx_length_errors++;
 624                dev_kfree_skb(skb);
 625                return;
 626        }
 627        dev->stats.rx_packets++;
 628        dev->stats.rx_bytes += skb->len;
 629
 630        /* length field is exchanged in network byte order */
 631        ((u16 *)skb->data)[2] = ntohs(((u16 *)skb->data)[2]);
 632        dev_dbg(&dev->dev, "RX length fixed (%04x -> %u)\n",
 633                        ((u16 *)skb->data)[2], ntohs(((u16 *)skb->data)[2]));
 634
 635        skb->protocol = htons(ETH_P_PHONET);
 636        skb_reset_mac_header(skb);
 637        __skb_pull(skb, 1);
 638        netif_rx(skb);
 639}
 640
 641static void ssip_rx_data_complete(struct hsi_msg *msg)
 642{
 643        struct hsi_client *cl = msg->cl;
 644        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 645        struct sk_buff *skb;
 646
 647        if (msg->status == HSI_STATUS_ERROR) {
 648                dev_err(&cl->device, "RX data error\n");
 649                ssip_free_data(msg);
 650                ssip_error(cl);
 651                return;
 652        }
 653        del_timer(&ssi->rx_wd); /* FIXME: Revisit */
 654        skb = msg->context;
 655        ssip_pn_rx(skb);
 656        hsi_free_msg(msg);
 657}
 658
 659static void ssip_rx_bootinforeq(struct hsi_client *cl, u32 cmd)
 660{
 661        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 662        struct hsi_msg *msg;
 663
 664        /* Workaroud: Ignore CMT Loader message leftover */
 665        if (cmd == SSIP_CMT_LOADER_SYNC)
 666                return;
 667
 668        switch (ssi->main_state) {
 669        case ACTIVE:
 670                dev_err(&cl->device, "Boot info req on active state\n");
 671                ssip_error(cl);
 672                /* Fall through */
 673        case INIT:
 674                spin_lock(&ssi->lock);
 675                ssi->main_state = HANDSHAKE;
 676                if (!ssi->waketest) {
 677                        ssi->waketest = 1;
 678                        ssi_waketest(cl, 1); /* FIXME: To be removed */
 679                }
 680                /* Start boot handshake watchdog */
 681                mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
 682                spin_unlock(&ssi->lock);
 683                dev_dbg(&cl->device, "Send BOOTINFO_RESP\n");
 684                if (SSIP_DATA_VERSION(cmd) != SSIP_LOCAL_VERID)
 685                        dev_warn(&cl->device, "boot info req verid mismatch\n");
 686                msg = ssip_claim_cmd(ssi);
 687                ssip_set_cmd(msg, SSIP_BOOTINFO_RESP_CMD(SSIP_LOCAL_VERID));
 688                msg->complete = ssip_release_cmd;
 689                hsi_async_write(cl, msg);
 690                break;
 691        case HANDSHAKE:
 692                /* Ignore */
 693                break;
 694        default:
 695                dev_dbg(&cl->device, "Wrong state M(%d)\n", ssi->main_state);
 696                break;
 697        }
 698}
 699
 700static void ssip_rx_bootinforesp(struct hsi_client *cl, u32 cmd)
 701{
 702        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 703
 704        if (SSIP_DATA_VERSION(cmd) != SSIP_LOCAL_VERID)
 705                dev_warn(&cl->device, "boot info resp verid mismatch\n");
 706
 707        spin_lock(&ssi->lock);
 708        if (ssi->main_state != ACTIVE)
 709                /* Use tx_wd as a boot watchdog in non ACTIVE state */
 710                mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
 711        else
 712                dev_dbg(&cl->device, "boot info resp ignored M(%d)\n",
 713                                                        ssi->main_state);
 714        spin_unlock(&ssi->lock);
 715}
 716
 717static void ssip_rx_waketest(struct hsi_client *cl, u32 cmd)
 718{
 719        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 720        unsigned int wkres = SSIP_PAYLOAD(cmd);
 721
 722        spin_lock(&ssi->lock);
 723        if (ssi->main_state != HANDSHAKE) {
 724                dev_dbg(&cl->device, "wake lines test ignored M(%d)\n",
 725                                                        ssi->main_state);
 726                spin_unlock(&ssi->lock);
 727                return;
 728        }
 729        if (ssi->waketest) {
 730                ssi->waketest = 0;
 731                ssi_waketest(cl, 0); /* FIXME: To be removed */
 732        }
 733        ssi->main_state = ACTIVE;
 734        del_timer(&ssi->tx_wd); /* Stop boot handshake timer */
 735        spin_unlock(&ssi->lock);
 736
 737        dev_notice(&cl->device, "WAKELINES TEST %s\n",
 738                                wkres & SSIP_WAKETEST_FAILED ? "FAILED" : "OK");
 739        if (wkres & SSIP_WAKETEST_FAILED) {
 740                ssip_error(cl);
 741                return;
 742        }
 743        dev_dbg(&cl->device, "CMT is ONLINE\n");
 744        netif_wake_queue(ssi->netdev);
 745        netif_carrier_on(ssi->netdev);
 746}
 747
 748static void ssip_rx_ready(struct hsi_client *cl)
 749{
 750        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 751
 752        spin_lock(&ssi->lock);
 753        if (unlikely(ssi->main_state != ACTIVE)) {
 754                dev_dbg(&cl->device, "READY on wrong state: S(%d) M(%d)\n",
 755                                        ssi->send_state, ssi->main_state);
 756                spin_unlock(&ssi->lock);
 757                return;
 758        }
 759        if (ssi->send_state != WAIT4READY) {
 760                dev_dbg(&cl->device, "Ignore spurious READY command\n");
 761                spin_unlock(&ssi->lock);
 762                return;
 763        }
 764        ssip_set_txstate(ssi, SEND_READY);
 765        spin_unlock(&ssi->lock);
 766        ssip_xmit(cl);
 767}
 768
 769static void ssip_rx_strans(struct hsi_client *cl, u32 cmd)
 770{
 771        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 772        struct sk_buff *skb;
 773        struct hsi_msg *msg;
 774        int len = SSIP_PDU_LENGTH(cmd);
 775
 776        dev_dbg(&cl->device, "RX strans: %d frames\n", len);
 777        spin_lock(&ssi->lock);
 778        if (unlikely(ssi->main_state != ACTIVE)) {
 779                dev_err(&cl->device, "START TRANS wrong state: S(%d) M(%d)\n",
 780                                        ssi->send_state, ssi->main_state);
 781                spin_unlock(&ssi->lock);
 782                return;
 783        }
 784        ssip_set_rxstate(ssi, RECEIVING);
 785        if (unlikely(SSIP_MSG_ID(cmd) != ssi->rxid)) {
 786                dev_err(&cl->device, "START TRANS id %d expeceted %d\n",
 787                                        SSIP_MSG_ID(cmd), ssi->rxid);
 788                spin_unlock(&ssi->lock);
 789                goto out1;
 790        }
 791        ssi->rxid++;
 792        spin_unlock(&ssi->lock);
 793        skb = netdev_alloc_skb(ssi->netdev, len * 4);
 794        if (unlikely(!skb)) {
 795                dev_err(&cl->device, "No memory for rx skb\n");
 796                goto out1;
 797        }
 798        skb->dev = ssi->netdev;
 799        skb_put(skb, len * 4);
 800        msg = ssip_alloc_data(ssi, skb, GFP_ATOMIC);
 801        if (unlikely(!msg)) {
 802                dev_err(&cl->device, "No memory for RX data msg\n");
 803                goto out2;
 804        }
 805        msg->complete = ssip_rx_data_complete;
 806        hsi_async_read(cl, msg);
 807
 808        return;
 809out2:
 810        dev_kfree_skb(skb);
 811out1:
 812        ssip_error(cl);
 813}
 814
 815static void ssip_rxcmd_complete(struct hsi_msg *msg)
 816{
 817        struct hsi_client *cl = msg->cl;
 818        u32 cmd = ssip_get_cmd(msg);
 819        unsigned int cmdid = SSIP_COMMAND(cmd);
 820
 821        if (msg->status == HSI_STATUS_ERROR) {
 822                dev_err(&cl->device, "RX error detected\n");
 823                ssip_release_cmd(msg);
 824                ssip_error(cl);
 825                return;
 826        }
 827        hsi_async_read(cl, msg);
 828        dev_dbg(&cl->device, "RX cmd: 0x%08x\n", cmd);
 829        switch (cmdid) {
 830        case SSIP_SW_BREAK:
 831                /* Ignored */
 832                break;
 833        case SSIP_BOOTINFO_REQ:
 834                ssip_rx_bootinforeq(cl, cmd);
 835                break;
 836        case SSIP_BOOTINFO_RESP:
 837                ssip_rx_bootinforesp(cl, cmd);
 838                break;
 839        case SSIP_WAKETEST_RESULT:
 840                ssip_rx_waketest(cl, cmd);
 841                break;
 842        case SSIP_START_TRANS:
 843                ssip_rx_strans(cl, cmd);
 844                break;
 845        case SSIP_READY:
 846                ssip_rx_ready(cl);
 847                break;
 848        default:
 849                dev_warn(&cl->device, "command 0x%08x not supported\n", cmd);
 850                break;
 851        }
 852}
 853
 854static void ssip_swbreak_complete(struct hsi_msg *msg)
 855{
 856        struct hsi_client *cl = msg->cl;
 857        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 858
 859        ssip_release_cmd(msg);
 860        spin_lock(&ssi->lock);
 861        if (list_empty(&ssi->txqueue)) {
 862                if (atomic_read(&ssi->tx_usecnt)) {
 863                        ssip_set_txstate(ssi, SEND_READY);
 864                } else {
 865                        ssip_set_txstate(ssi, SEND_IDLE);
 866                        hsi_stop_tx(cl);
 867                }
 868                spin_unlock(&ssi->lock);
 869        } else {
 870                spin_unlock(&ssi->lock);
 871                ssip_xmit(cl);
 872        }
 873        netif_wake_queue(ssi->netdev);
 874}
 875
 876static void ssip_tx_data_complete(struct hsi_msg *msg)
 877{
 878        struct hsi_client *cl = msg->cl;
 879        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 880        struct hsi_msg *cmsg;
 881
 882        if (msg->status == HSI_STATUS_ERROR) {
 883                dev_err(&cl->device, "TX data error\n");
 884                ssip_error(cl);
 885                goto out;
 886        }
 887        spin_lock(&ssi->lock);
 888        if (list_empty(&ssi->txqueue)) {
 889                ssip_set_txstate(ssi, SENDING_SWBREAK);
 890                spin_unlock(&ssi->lock);
 891                cmsg = ssip_claim_cmd(ssi);
 892                ssip_set_cmd(cmsg, SSIP_SWBREAK_CMD);
 893                cmsg->complete = ssip_swbreak_complete;
 894                dev_dbg(&cl->device, "Send SWBREAK\n");
 895                hsi_async_write(cl, cmsg);
 896        } else {
 897                spin_unlock(&ssi->lock);
 898                ssip_xmit(cl);
 899        }
 900out:
 901        ssip_free_data(msg);
 902}
 903
 904static void ssip_port_event(struct hsi_client *cl, unsigned long event)
 905{
 906        switch (event) {
 907        case HSI_EVENT_START_RX:
 908                ssip_start_rx(cl);
 909                break;
 910        case HSI_EVENT_STOP_RX:
 911                ssip_stop_rx(cl);
 912                break;
 913        default:
 914                return;
 915        }
 916}
 917
 918static int ssip_pn_open(struct net_device *dev)
 919{
 920        struct hsi_client *cl = to_hsi_client(dev->dev.parent);
 921        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 922        int err;
 923
 924        err = hsi_claim_port(cl, 1);
 925        if (err < 0) {
 926                dev_err(&cl->device, "SSI port already claimed\n");
 927                return err;
 928        }
 929        err = hsi_register_port_event(cl, ssip_port_event);
 930        if (err < 0) {
 931                dev_err(&cl->device, "Register HSI port event failed (%d)\n",
 932                        err);
 933                return err;
 934        }
 935        dev_dbg(&cl->device, "Configuring SSI port\n");
 936        hsi_setup(cl);
 937        spin_lock_bh(&ssi->lock);
 938        if (!ssi->waketest) {
 939                ssi->waketest = 1;
 940                ssi_waketest(cl, 1); /* FIXME: To be removed */
 941        }
 942        ssi->main_state = INIT;
 943        spin_unlock_bh(&ssi->lock);
 944
 945        return 0;
 946}
 947
 948static int ssip_pn_stop(struct net_device *dev)
 949{
 950        struct hsi_client *cl = to_hsi_client(dev->dev.parent);
 951
 952        ssip_reset(cl);
 953        hsi_unregister_port_event(cl);
 954        hsi_release_port(cl);
 955
 956        return 0;
 957}
 958
 959static int ssip_pn_set_mtu(struct net_device *dev, int new_mtu)
 960{
 961        if (new_mtu > SSIP_MAX_MTU || new_mtu < PHONET_MIN_MTU)
 962                return -EINVAL;
 963        dev->mtu = new_mtu;
 964
 965        return 0;
 966}
 967
 968static int ssip_pn_xmit(struct sk_buff *skb, struct net_device *dev)
 969{
 970        struct hsi_client *cl = to_hsi_client(dev->dev.parent);
 971        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
 972        struct hsi_msg *msg;
 973
 974        if ((skb->protocol != htons(ETH_P_PHONET)) ||
 975                                        (skb->len < SSIP_MIN_PN_HDR))
 976                goto drop;
 977        /* Pad to 32-bits - FIXME: Revisit*/
 978        if ((skb->len & 3) && skb_pad(skb, 4 - (skb->len & 3)))
 979                goto drop;
 980
 981        /*
 982         * Modem sends Phonet messages over SSI with its own endianess...
 983         * Assume that modem has the same endianess as we do.
 984         */
 985        if (skb_cow_head(skb, 0))
 986                goto drop;
 987
 988        /* length field is exchanged in network byte order */
 989        ((u16 *)skb->data)[2] = htons(((u16 *)skb->data)[2]);
 990
 991        msg = ssip_alloc_data(ssi, skb, GFP_ATOMIC);
 992        if (!msg) {
 993                dev_dbg(&cl->device, "Dropping tx data: No memory\n");
 994                goto drop;
 995        }
 996        msg->complete = ssip_tx_data_complete;
 997
 998        spin_lock_bh(&ssi->lock);
 999        if (unlikely(ssi->main_state != ACTIVE)) {
1000                spin_unlock_bh(&ssi->lock);
1001                dev_dbg(&cl->device, "Dropping tx data: CMT is OFFLINE\n");
1002                goto drop2;
1003        }
1004        list_add_tail(&msg->link, &ssi->txqueue);
1005        ssi->txqueue_len++;
1006        if (dev->tx_queue_len < ssi->txqueue_len) {
1007                dev_info(&cl->device, "TX queue full %d\n", ssi->txqueue_len);
1008                netif_stop_queue(dev);
1009        }
1010        if (ssi->send_state == SEND_IDLE) {
1011                ssip_set_txstate(ssi, WAIT4READY);
1012                spin_unlock_bh(&ssi->lock);
1013                dev_dbg(&cl->device, "Start TX qlen %d\n", ssi->txqueue_len);
1014                hsi_start_tx(cl);
1015        } else if (ssi->send_state == SEND_READY) {
1016                /* Needed for cmt-speech workaround */
1017                dev_dbg(&cl->device, "Start TX on SEND READY qlen %d\n",
1018                                                        ssi->txqueue_len);
1019                spin_unlock_bh(&ssi->lock);
1020                ssip_xmit(cl);
1021        } else {
1022                spin_unlock_bh(&ssi->lock);
1023        }
1024        dev->stats.tx_packets++;
1025        dev->stats.tx_bytes += skb->len;
1026
1027        return 0;
1028drop2:
1029        hsi_free_msg(msg);
1030drop:
1031        dev->stats.tx_dropped++;
1032        dev_kfree_skb(skb);
1033
1034        return 0;
1035}
1036
1037/* CMT reset event handler */
1038void ssip_reset_event(struct hsi_client *master)
1039{
1040        struct ssi_protocol *ssi = hsi_client_drvdata(master);
1041        dev_err(&ssi->cl->device, "CMT reset detected!\n");
1042        ssip_error(ssi->cl);
1043}
1044EXPORT_SYMBOL_GPL(ssip_reset_event);
1045
1046static const struct net_device_ops ssip_pn_ops = {
1047        .ndo_open       = ssip_pn_open,
1048        .ndo_stop       = ssip_pn_stop,
1049        .ndo_start_xmit = ssip_pn_xmit,
1050        .ndo_change_mtu = ssip_pn_set_mtu,
1051};
1052
1053static void ssip_pn_setup(struct net_device *dev)
1054{
1055        dev->features           = 0;
1056        dev->netdev_ops         = &ssip_pn_ops;
1057        dev->type               = ARPHRD_PHONET;
1058        dev->flags              = IFF_POINTOPOINT | IFF_NOARP;
1059        dev->mtu                = SSIP_DEFAULT_MTU;
1060        dev->hard_header_len    = 1;
1061        dev->dev_addr[0]        = PN_MEDIA_SOS;
1062        dev->addr_len           = 1;
1063        dev->tx_queue_len       = SSIP_TXQUEUE_LEN;
1064
1065        dev->destructor         = free_netdev;
1066        dev->header_ops         = &phonet_header_ops;
1067}
1068
1069static int ssi_protocol_probe(struct device *dev)
1070{
1071        static const char ifname[] = "phonet%d";
1072        struct hsi_client *cl = to_hsi_client(dev);
1073        struct ssi_protocol *ssi;
1074        int err;
1075
1076        ssi = kzalloc(sizeof(*ssi), GFP_KERNEL);
1077        if (!ssi) {
1078                dev_err(dev, "No memory for ssi protocol\n");
1079                return -ENOMEM;
1080        }
1081
1082        spin_lock_init(&ssi->lock);
1083        init_timer_deferrable(&ssi->rx_wd);
1084        init_timer_deferrable(&ssi->tx_wd);
1085        init_timer(&ssi->keep_alive);
1086        ssi->rx_wd.data = (unsigned long)cl;
1087        ssi->rx_wd.function = ssip_wd;
1088        ssi->tx_wd.data = (unsigned long)cl;
1089        ssi->tx_wd.function = ssip_wd;
1090        ssi->keep_alive.data = (unsigned long)cl;
1091        ssi->keep_alive.function = ssip_keep_alive;
1092        INIT_LIST_HEAD(&ssi->txqueue);
1093        INIT_LIST_HEAD(&ssi->cmdqueue);
1094        atomic_set(&ssi->tx_usecnt, 0);
1095        hsi_client_set_drvdata(cl, ssi);
1096        ssi->cl = cl;
1097
1098        ssi->channel_id_cmd = hsi_get_channel_id_by_name(cl, "mcsaab-control");
1099        if (ssi->channel_id_cmd < 0) {
1100                err = ssi->channel_id_cmd;
1101                dev_err(dev, "Could not get cmd channel (%d)\n", err);
1102                goto out;
1103        }
1104
1105        ssi->channel_id_data = hsi_get_channel_id_by_name(cl, "mcsaab-data");
1106        if (ssi->channel_id_data < 0) {
1107                err = ssi->channel_id_data;
1108                dev_err(dev, "Could not get data channel (%d)\n", err);
1109                goto out;
1110        }
1111
1112        err = ssip_alloc_cmds(ssi);
1113        if (err < 0) {
1114                dev_err(dev, "No memory for commands\n");
1115                goto out;
1116        }
1117
1118        ssi->netdev = alloc_netdev(0, ifname, NET_NAME_UNKNOWN, ssip_pn_setup);
1119        if (!ssi->netdev) {
1120                dev_err(dev, "No memory for netdev\n");
1121                err = -ENOMEM;
1122                goto out1;
1123        }
1124
1125        SET_NETDEV_DEV(ssi->netdev, dev);
1126        netif_carrier_off(ssi->netdev);
1127        err = register_netdev(ssi->netdev);
1128        if (err < 0) {
1129                dev_err(dev, "Register netdev failed (%d)\n", err);
1130                goto out2;
1131        }
1132
1133        list_add(&ssi->link, &ssip_list);
1134
1135        dev_dbg(dev, "channel configuration: cmd=%d, data=%d\n",
1136                ssi->channel_id_cmd, ssi->channel_id_data);
1137
1138        return 0;
1139out2:
1140        free_netdev(ssi->netdev);
1141out1:
1142        ssip_free_cmds(ssi);
1143out:
1144        kfree(ssi);
1145
1146        return err;
1147}
1148
1149static int ssi_protocol_remove(struct device *dev)
1150{
1151        struct hsi_client *cl = to_hsi_client(dev);
1152        struct ssi_protocol *ssi = hsi_client_drvdata(cl);
1153
1154        list_del(&ssi->link);
1155        unregister_netdev(ssi->netdev);
1156        ssip_free_cmds(ssi);
1157        hsi_client_set_drvdata(cl, NULL);
1158        kfree(ssi);
1159
1160        return 0;
1161}
1162
1163static struct hsi_client_driver ssip_driver = {
1164        .driver = {
1165                .name   = "ssi-protocol",
1166                .owner  = THIS_MODULE,
1167                .probe  = ssi_protocol_probe,
1168                .remove = ssi_protocol_remove,
1169        },
1170};
1171
1172static int __init ssip_init(void)
1173{
1174        pr_info("SSI protocol aka McSAAB added\n");
1175
1176        return hsi_register_client_driver(&ssip_driver);
1177}
1178module_init(ssip_init);
1179
1180static void __exit ssip_exit(void)
1181{
1182        hsi_unregister_client_driver(&ssip_driver);
1183        pr_info("SSI protocol driver removed\n");
1184}
1185module_exit(ssip_exit);
1186
1187MODULE_ALIAS("hsi:ssi-protocol");
1188MODULE_AUTHOR("Carlos Chinea <carlos.chinea@nokia.com>");
1189MODULE_AUTHOR("Remi Denis-Courmont <remi.denis-courmont@nokia.com>");
1190MODULE_DESCRIPTION("SSI protocol improved aka McSAAB");
1191MODULE_LICENSE("GPL");
1192