HSI: Introduce driver for SSI Protocol
authorSebastian Reichel <sre@kernel.org>
Fri, 15 Nov 2013 10:50:32 +0000 (10:50 +0000)
committerSebastian Reichel <sre@kernel.org>
Thu, 15 May 2014 22:55:30 +0000 (00:55 +0200)
This adds a driver for the SSI McSAAB protocol as used in
the Nokia N900.

Signed-off-by: Carlos Chinea <carlos.chinea@nokia.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Tested-By: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
drivers/hsi/clients/Kconfig
drivers/hsi/clients/Makefile
drivers/hsi/clients/ssi_protocol.c [new file with mode: 0644]
include/linux/hsi/ssi_protocol.h [new file with mode: 0644]

index 3bacd27..1457cfb 100644 (file)
@@ -4,6 +4,14 @@
 
 comment "HSI clients"
 
+config SSI_PROTOCOL
+       tristate "SSI protocol"
+       depends on HSI && PHONET && (OMAP_SSI=y || OMAP_SSI=m)
+       help
+       If you say Y here, you will enable the SSI protocol aka McSAAB.
+
+       If unsure, say N.
+
 config HSI_CHAR
        tristate "HSI/SSI character driver"
        depends on HSI
index 327c0e2..ccbf768 100644 (file)
@@ -2,4 +2,5 @@
 # Makefile for HSI clients
 #
 
-obj-$(CONFIG_HSI_CHAR) += hsi_char.o
+obj-$(CONFIG_SSI_PROTOCOL)     += ssi_protocol.o
+obj-$(CONFIG_HSI_CHAR)         += hsi_char.o
diff --git a/drivers/hsi/clients/ssi_protocol.c b/drivers/hsi/clients/ssi_protocol.c
new file mode 100644 (file)
index 0000000..ce4be37
--- /dev/null
@@ -0,0 +1,1191 @@
+/*
+ * ssi_protocol.c
+ *
+ * Implementation of the SSI McSAAB improved protocol.
+ *
+ * Copyright (C) 2010 Nokia Corporation. All rights reserved.
+ * Copyright (C) 2013 Sebastian Reichel <sre@kernel.org>
+ *
+ * Contact: Carlos Chinea <carlos.chinea@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#include <linux/atomic.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/if_ether.h>
+#include <linux/if_arp.h>
+#include <linux/if_phonet.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/notifier.h>
+#include <linux/scatterlist.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/timer.h>
+#include <linux/hsi/hsi.h>
+#include <linux/hsi/ssi_protocol.h>
+
+void ssi_waketest(struct hsi_client *cl, unsigned int enable);
+
+#define SSIP_TXQUEUE_LEN       100
+#define SSIP_MAX_MTU           65535
+#define SSIP_DEFAULT_MTU       4000
+#define PN_MEDIA_SOS           21
+#define SSIP_MIN_PN_HDR                6       /* FIXME: Revisit */
+#define SSIP_WDTOUT            2000    /* FIXME: has to be 500 msecs */
+#define SSIP_KATOUT            15      /* 15 msecs */
+#define SSIP_MAX_CMDS          5 /* Number of pre-allocated commands buffers */
+#define SSIP_BYTES_TO_FRAMES(x) ((((x) - 1) >> 2) + 1)
+#define SSIP_CMT_LOADER_SYNC   0x11223344
+/*
+ * SSI protocol command definitions
+ */
+#define SSIP_COMMAND(data)     ((data) >> 28)
+#define SSIP_PAYLOAD(data)     ((data) & 0xfffffff)
+/* Commands */
+#define SSIP_SW_BREAK          0
+#define SSIP_BOOTINFO_REQ      1
+#define SSIP_BOOTINFO_RESP     2
+#define SSIP_WAKETEST_RESULT   3
+#define SSIP_START_TRANS       4
+#define SSIP_READY             5
+/* Payloads */
+#define SSIP_DATA_VERSION(data)        ((data) & 0xff)
+#define SSIP_LOCAL_VERID       1
+#define SSIP_WAKETEST_OK       0
+#define SSIP_WAKETEST_FAILED   1
+#define SSIP_PDU_LENGTH(data)  (((data) >> 8) & 0xffff)
+#define SSIP_MSG_ID(data)      ((data) & 0xff)
+/* Generic Command */
+#define SSIP_CMD(cmd, payload) (((cmd) << 28) | ((payload) & 0xfffffff))
+/* Commands for the control channel */
+#define SSIP_BOOTINFO_REQ_CMD(ver) \
+               SSIP_CMD(SSIP_BOOTINFO_REQ, SSIP_DATA_VERSION(ver))
+#define SSIP_BOOTINFO_RESP_CMD(ver) \
+               SSIP_CMD(SSIP_BOOTINFO_RESP, SSIP_DATA_VERSION(ver))
+#define SSIP_START_TRANS_CMD(pdulen, id) \
+               SSIP_CMD(SSIP_START_TRANS, (((pdulen) << 8) | SSIP_MSG_ID(id)))
+#define SSIP_READY_CMD         SSIP_CMD(SSIP_READY, 0)
+#define SSIP_SWBREAK_CMD       SSIP_CMD(SSIP_SW_BREAK, 0)
+
+/* Main state machine states */
+enum {
+       INIT,
+       HANDSHAKE,
+       ACTIVE,
+};
+
+/* Send state machine states */
+enum {
+       SEND_IDLE,
+       WAIT4READY,
+       SEND_READY,
+       SENDING,
+       SENDING_SWBREAK,
+};
+
+/* Receive state machine states */
+enum {
+       RECV_IDLE,
+       RECV_READY,
+       RECEIVING,
+};
+
+/**
+ * struct ssi_protocol - SSI protocol (McSAAB) data
+ * @main_state: Main state machine
+ * @send_state: TX state machine
+ * @recv_state: RX state machine
+ * @waketest: Flag to follow wake line test
+ * @rxid: RX data id
+ * @txid: TX data id
+ * @txqueue_len: TX queue length
+ * @tx_wd: TX watchdog
+ * @rx_wd: RX watchdog
+ * @keep_alive: Workaround for SSI HW bug
+ * @lock: To serialize access to this struct
+ * @netdev: Phonet network device
+ * @txqueue: TX data queue
+ * @cmdqueue: Queue of free commands
+ * @cl: HSI client own reference
+ * @link: Link for ssip_list
+ * @tx_usecount: Refcount to keep track the slaves that use the wake line
+ * @channel_id_cmd: HSI channel id for command stream
+ * @channel_id_data: HSI channel id for data stream
+ */
+struct ssi_protocol {
+       unsigned int            main_state;
+       unsigned int            send_state;
+       unsigned int            recv_state;
+       unsigned int            waketest:1;
+       u8                      rxid;
+       u8                      txid;
+       unsigned int            txqueue_len;
+       struct timer_list       tx_wd;
+       struct timer_list       rx_wd;
+       struct timer_list       keep_alive; /* wake-up workaround */
+       spinlock_t              lock;
+       struct net_device       *netdev;
+       struct list_head        txqueue;
+       struct list_head        cmdqueue;
+       struct hsi_client       *cl;
+       struct list_head        link;
+       atomic_t                tx_usecnt;
+       int                     channel_id_cmd;
+       int                     channel_id_data;
+};
+
+/* List of ssi protocol instances */
+static LIST_HEAD(ssip_list);
+
+static void ssip_rxcmd_complete(struct hsi_msg *msg);
+
+static inline void ssip_set_cmd(struct hsi_msg *msg, u32 cmd)
+{
+       u32 *data;
+
+       data = sg_virt(msg->sgt.sgl);
+       *data = cmd;
+}
+
+static inline u32 ssip_get_cmd(struct hsi_msg *msg)
+{
+       u32 *data;
+
+       data = sg_virt(msg->sgt.sgl);
+
+       return *data;
+}
+
+static void ssip_skb_to_msg(struct sk_buff *skb, struct hsi_msg *msg)
+{
+       skb_frag_t *frag;
+       struct scatterlist *sg;
+       int i;
+
+       BUG_ON(msg->sgt.nents != (unsigned int)(skb_shinfo(skb)->nr_frags + 1));
+
+       sg = msg->sgt.sgl;
+       sg_set_buf(sg, skb->data, skb_headlen(skb));
+       for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+               sg = sg_next(sg);
+               BUG_ON(!sg);
+               frag = &skb_shinfo(skb)->frags[i];
+               sg_set_page(sg, frag->page.p, frag->size, frag->page_offset);
+       }
+}
+
+static void ssip_free_data(struct hsi_msg *msg)
+{
+       struct sk_buff *skb;
+
+       skb = msg->context;
+       pr_debug("free data: msg %p context %p skb %p\n", msg, msg->context,
+                                                               skb);
+       msg->destructor = NULL;
+       dev_kfree_skb(skb);
+       hsi_free_msg(msg);
+}
+
+static struct hsi_msg *ssip_alloc_data(struct ssi_protocol *ssi,
+                                       struct sk_buff *skb, gfp_t flags)
+{
+       struct hsi_msg *msg;
+
+       msg = hsi_alloc_msg(skb_shinfo(skb)->nr_frags + 1, flags);
+       if (!msg)
+               return NULL;
+       ssip_skb_to_msg(skb, msg);
+       msg->destructor = ssip_free_data;
+       msg->channel = ssi->channel_id_data;
+       msg->context = skb;
+
+       return msg;
+}
+
+static inline void ssip_release_cmd(struct hsi_msg *msg)
+{
+       struct ssi_protocol *ssi = hsi_client_drvdata(msg->cl);
+
+       dev_dbg(&msg->cl->device, "Release cmd 0x%08x\n", ssip_get_cmd(msg));
+       spin_lock_bh(&ssi->lock);
+       list_add_tail(&msg->link, &ssi->cmdqueue);
+       spin_unlock_bh(&ssi->lock);
+}
+
+static struct hsi_msg *ssip_claim_cmd(struct ssi_protocol *ssi)
+{
+       struct hsi_msg *msg;
+
+       BUG_ON(list_empty(&ssi->cmdqueue));
+
+       spin_lock_bh(&ssi->lock);
+       msg = list_first_entry(&ssi->cmdqueue, struct hsi_msg, link);
+       list_del(&msg->link);
+       spin_unlock_bh(&ssi->lock);
+       msg->destructor = ssip_release_cmd;
+
+       return msg;
+}
+
+static void ssip_free_cmds(struct ssi_protocol *ssi)
+{
+       struct hsi_msg *msg, *tmp;
+
+       list_for_each_entry_safe(msg, tmp, &ssi->cmdqueue, link) {
+               list_del(&msg->link);
+               msg->destructor = NULL;
+               kfree(sg_virt(msg->sgt.sgl));
+               hsi_free_msg(msg);
+       }
+}
+
+static int ssip_alloc_cmds(struct ssi_protocol *ssi)
+{
+       struct hsi_msg *msg;
+       u32 *buf;
+       unsigned int i;
+
+       for (i = 0; i < SSIP_MAX_CMDS; i++) {
+               msg = hsi_alloc_msg(1, GFP_KERNEL);
+               if (!msg)
+                       goto out;
+               buf = kmalloc(sizeof(*buf), GFP_KERNEL);
+               if (!buf) {
+                       hsi_free_msg(msg);
+                       goto out;
+               }
+               sg_init_one(msg->sgt.sgl, buf, sizeof(*buf));
+               msg->channel = ssi->channel_id_cmd;
+               list_add_tail(&msg->link, &ssi->cmdqueue);
+       }
+
+       return 0;
+out:
+       ssip_free_cmds(ssi);
+
+       return -ENOMEM;
+}
+
+static void ssip_set_rxstate(struct ssi_protocol *ssi, unsigned int state)
+{
+       ssi->recv_state = state;
+       switch (state) {
+       case RECV_IDLE:
+               del_timer(&ssi->rx_wd);
+               if (ssi->send_state == SEND_IDLE)
+                       del_timer(&ssi->keep_alive);
+               break;
+       case RECV_READY:
+               /* CMT speech workaround */
+               if (atomic_read(&ssi->tx_usecnt))
+                       break;
+               /* Otherwise fall through */
+       case RECEIVING:
+               mod_timer(&ssi->keep_alive, jiffies +
+                                               msecs_to_jiffies(SSIP_KATOUT));
+               mod_timer(&ssi->rx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
+               break;
+       default:
+               break;
+       }
+}
+
+static void ssip_set_txstate(struct ssi_protocol *ssi, unsigned int state)
+{
+       ssi->send_state = state;
+       switch (state) {
+       case SEND_IDLE:
+       case SEND_READY:
+               del_timer(&ssi->tx_wd);
+               if (ssi->recv_state == RECV_IDLE)
+                       del_timer(&ssi->keep_alive);
+               break;
+       case WAIT4READY:
+       case SENDING:
+       case SENDING_SWBREAK:
+               mod_timer(&ssi->keep_alive,
+                               jiffies + msecs_to_jiffies(SSIP_KATOUT));
+               mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
+               break;
+       default:
+               break;
+       }
+}
+
+struct hsi_client *ssip_slave_get_master(struct hsi_client *slave)
+{
+       struct hsi_client *master = ERR_PTR(-ENODEV);
+       struct ssi_protocol *ssi;
+
+       list_for_each_entry(ssi, &ssip_list, link)
+               if (slave->device.parent == ssi->cl->device.parent) {
+                       master = ssi->cl;
+                       break;
+               }
+
+       return master;
+}
+EXPORT_SYMBOL_GPL(ssip_slave_get_master);
+
+int ssip_slave_start_tx(struct hsi_client *master)
+{
+       struct ssi_protocol *ssi = hsi_client_drvdata(master);
+
+       dev_dbg(&master->device, "start TX %d\n", atomic_read(&ssi->tx_usecnt));
+       spin_lock_bh(&ssi->lock);
+       if (ssi->send_state == SEND_IDLE) {
+               ssip_set_txstate(ssi, WAIT4READY);
+               hsi_start_tx(master);
+       }
+       spin_unlock_bh(&ssi->lock);
+       atomic_inc(&ssi->tx_usecnt);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(ssip_slave_start_tx);
+
+int ssip_slave_stop_tx(struct hsi_client *master)
+{
+       struct ssi_protocol *ssi = hsi_client_drvdata(master);
+
+       WARN_ON_ONCE(atomic_read(&ssi->tx_usecnt) == 0);
+
+       if (atomic_dec_and_test(&ssi->tx_usecnt)) {
+               spin_lock_bh(&ssi->lock);
+               if ((ssi->send_state == SEND_READY) ||
+                       (ssi->send_state == WAIT4READY)) {
+                       ssip_set_txstate(ssi, SEND_IDLE);
+                       hsi_stop_tx(master);
+               }
+               spin_unlock_bh(&ssi->lock);
+       }
+       dev_dbg(&master->device, "stop TX %d\n", atomic_read(&ssi->tx_usecnt));
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(ssip_slave_stop_tx);
+
+int ssip_slave_running(struct hsi_client *master)
+{
+       struct ssi_protocol *ssi = hsi_client_drvdata(master);
+       return netif_running(ssi->netdev);
+}
+EXPORT_SYMBOL_GPL(ssip_slave_running);
+
+static void ssip_reset(struct hsi_client *cl)
+{
+       struct ssi_protocol *ssi = hsi_client_drvdata(cl);
+       struct list_head *head, *tmp;
+       struct hsi_msg *msg;
+
+       if (netif_running(ssi->netdev))
+               netif_carrier_off(ssi->netdev);
+       hsi_flush(cl);
+       spin_lock_bh(&ssi->lock);
+       if (ssi->send_state != SEND_IDLE)
+               hsi_stop_tx(cl);
+       if (ssi->waketest)
+               ssi_waketest(cl, 0);
+       del_timer(&ssi->rx_wd);
+       del_timer(&ssi->tx_wd);
+       del_timer(&ssi->keep_alive);
+       ssi->main_state = 0;
+       ssi->send_state = 0;
+       ssi->recv_state = 0;
+       ssi->waketest = 0;
+       ssi->rxid = 0;
+       ssi->txid = 0;
+       list_for_each_safe(head, tmp, &ssi->txqueue) {
+               msg = list_entry(head, struct hsi_msg, link);
+               dev_dbg(&cl->device, "Pending TX data\n");
+               list_del(head);
+               ssip_free_data(msg);
+       }
+       ssi->txqueue_len = 0;
+       spin_unlock_bh(&ssi->lock);
+}
+
+static void ssip_dump_state(struct hsi_client *cl)
+{
+       struct ssi_protocol *ssi = hsi_client_drvdata(cl);
+       struct hsi_msg *msg;
+
+       spin_lock_bh(&ssi->lock);
+       dev_err(&cl->device, "Main state: %d\n", ssi->main_state);
+       dev_err(&cl->device, "Recv state: %d\n", ssi->recv_state);
+       dev_err(&cl->device, "Send state: %d\n", ssi->send_state);
+       dev_err(&cl->device, "CMT %s\n", (ssi->main_state == ACTIVE) ?
+                                                       "Online" : "Offline");
+       dev_err(&cl->device, "Wake test %d\n", ssi->waketest);
+       dev_err(&cl->device, "Data RX id: %d\n", ssi->rxid);
+       dev_err(&cl->device, "Data TX id: %d\n", ssi->txid);
+
+       list_for_each_entry(msg, &ssi->txqueue, link)
+               dev_err(&cl->device, "pending TX data (%p)\n", msg);
+       spin_unlock_bh(&ssi->lock);
+}
+
+static void ssip_error(struct hsi_client *cl)
+{
+       struct ssi_protocol *ssi = hsi_client_drvdata(cl);
+       struct hsi_msg *msg;
+
+       ssip_dump_state(cl);
+       ssip_reset(cl);
+       msg = ssip_claim_cmd(ssi);
+       msg->complete = ssip_rxcmd_complete;
+       hsi_async_read(cl, msg);
+}
+
+static void ssip_keep_alive(unsigned long data)
+{
+       struct hsi_client *cl = (struct hsi_client *)data;
+       struct ssi_protocol *ssi = hsi_client_drvdata(cl);
+
+       dev_dbg(&cl->device, "Keep alive kick in: m(%d) r(%d) s(%d)\n",
+               ssi->main_state, ssi->recv_state, ssi->send_state);
+
+       spin_lock(&ssi->lock);
+       if (ssi->recv_state == RECV_IDLE)
+               switch (ssi->send_state) {
+               case SEND_READY:
+                       if (atomic_read(&ssi->tx_usecnt) == 0)
+                               break;
+                       /*
+                        * Fall through. Workaround for cmt-speech
+                        * in that case we relay on audio timers.
+                        */
+               case SEND_IDLE:
+                       spin_unlock(&ssi->lock);
+                       return;
+               }
+       mod_timer(&ssi->keep_alive, jiffies + msecs_to_jiffies(SSIP_KATOUT));
+       spin_unlock(&ssi->lock);
+}
+
+static void ssip_wd(unsigned long data)
+{
+       struct hsi_client *cl = (struct hsi_client *)data;
+
+       dev_err(&cl->device, "Watchdog trigerred\n");
+       ssip_error(cl);
+}
+
+static void ssip_send_bootinfo_req_cmd(struct hsi_client *cl)
+{
+       struct ssi_protocol *ssi = hsi_client_drvdata(cl);
+       struct hsi_msg *msg;
+
+       dev_dbg(&cl->device, "Issuing BOOT INFO REQ command\n");
+       msg = ssip_claim_cmd(ssi);
+       ssip_set_cmd(msg, SSIP_BOOTINFO_REQ_CMD(SSIP_LOCAL_VERID));
+       msg->complete = ssip_release_cmd;
+       hsi_async_write(cl, msg);
+       dev_dbg(&cl->device, "Issuing RX command\n");
+       msg = ssip_claim_cmd(ssi);
+       msg->complete = ssip_rxcmd_complete;
+       hsi_async_read(cl, msg);
+}
+
+static void ssip_start_rx(struct hsi_client *cl)
+{
+       struct ssi_protocol *ssi = hsi_client_drvdata(cl);
+       struct hsi_msg *msg;
+
+       dev_dbg(&cl->device, "RX start M(%d) R(%d)\n", ssi->main_state,
+                                               ssi->recv_state);
+       spin_lock(&ssi->lock);
+       /*
+        * We can have two UP events in a row due to a short low
+        * high transition. Therefore we need to ignore the sencond UP event.
+        */
+       if ((ssi->main_state != ACTIVE) || (ssi->recv_state == RECV_READY)) {
+               if (ssi->main_state == INIT) {
+                       ssi->main_state = HANDSHAKE;
+                       spin_unlock(&ssi->lock);
+                       ssip_send_bootinfo_req_cmd(cl);
+               } else {
+                       spin_unlock(&ssi->lock);
+               }
+               return;
+       }
+       ssip_set_rxstate(ssi, RECV_READY);
+       spin_unlock(&ssi->lock);
+
+       msg = ssip_claim_cmd(ssi);
+       ssip_set_cmd(msg, SSIP_READY_CMD);
+       msg->complete = ssip_release_cmd;
+       dev_dbg(&cl->device, "Send READY\n");
+       hsi_async_write(cl, msg);
+}
+
+static void ssip_stop_rx(struct hsi_client *cl)
+{
+       struct ssi_protocol *ssi = hsi_client_drvdata(cl);
+
+       dev_dbg(&cl->device, "RX stop M(%d)\n", ssi->main_state);
+       spin_lock(&ssi->lock);
+       if (likely(ssi->main_state == ACTIVE))
+               ssip_set_rxstate(ssi, RECV_IDLE);
+       spin_unlock(&ssi->lock);
+}
+
+static void ssip_free_strans(struct hsi_msg *msg)
+{
+       ssip_free_data(msg->context);
+       ssip_release_cmd(msg);
+}
+
+static void ssip_strans_complete(struct hsi_msg *msg)
+{
+       struct hsi_client *cl = msg->cl;
+       struct ssi_protocol *ssi = hsi_client_drvdata(cl);
+       struct hsi_msg *data;
+
+       data = msg->context;
+       ssip_release_cmd(msg);
+       spin_lock(&ssi->lock);
+       ssip_set_txstate(ssi, SENDING);
+       spin_unlock(&ssi->lock);
+       hsi_async_write(cl, data);
+}
+
+static int ssip_xmit(struct hsi_client *cl)
+{
+       struct ssi_protocol *ssi = hsi_client_drvdata(cl);
+       struct hsi_msg *msg, *dmsg;
+       struct sk_buff *skb;
+
+       spin_lock_bh(&ssi->lock);
+       if (list_empty(&ssi->txqueue)) {
+               spin_unlock_bh(&ssi->lock);
+               return 0;
+       }
+       dmsg = list_first_entry(&ssi->txqueue, struct hsi_msg, link);
+       list_del(&dmsg->link);
+       ssi->txqueue_len--;
+       spin_unlock_bh(&ssi->lock);
+
+       msg = ssip_claim_cmd(ssi);
+       skb = dmsg->context;
+       msg->context = dmsg;
+       msg->complete = ssip_strans_complete;
+       msg->destructor = ssip_free_strans;
+
+       spin_lock_bh(&ssi->lock);
+       ssip_set_cmd(msg, SSIP_START_TRANS_CMD(SSIP_BYTES_TO_FRAMES(skb->len),
+                                                               ssi->txid));
+       ssi->txid++;
+       ssip_set_txstate(ssi, SENDING);
+       spin_unlock_bh(&ssi->lock);
+
+       dev_dbg(&cl->device, "Send STRANS (%d frames)\n",
+                                               SSIP_BYTES_TO_FRAMES(skb->len));
+
+       return hsi_async_write(cl, msg);
+}
+
+/* In soft IRQ context */
+static void ssip_pn_rx(struct sk_buff *skb)
+{
+       struct net_device *dev = skb->dev;
+
+       if (unlikely(!netif_running(dev))) {
+               dev_dbg(&dev->dev, "Drop RX packet\n");
+               dev->stats.rx_dropped++;
+               dev_kfree_skb(skb);
+               return;
+       }
+       if (unlikely(!pskb_may_pull(skb, SSIP_MIN_PN_HDR))) {
+               dev_dbg(&dev->dev, "Error drop RX packet\n");
+               dev->stats.rx_errors++;
+               dev->stats.rx_length_errors++;
+               dev_kfree_skb(skb);
+               return;
+       }
+       dev->stats.rx_packets++;
+       dev->stats.rx_bytes += skb->len;
+
+       /* length field is exchanged in network byte order */
+       ((u16 *)skb->data)[2] = ntohs(((u16 *)skb->data)[2]);
+       dev_dbg(&dev->dev, "RX length fixed (%04x -> %u)\n",
+                       ((u16 *)skb->data)[2], ntohs(((u16 *)skb->data)[2]));
+
+       skb->protocol = htons(ETH_P_PHONET);
+       skb_reset_mac_header(skb);
+       __skb_pull(skb, 1);
+       netif_rx(skb);
+}
+
+static void ssip_rx_data_complete(struct hsi_msg *msg)
+{
+       struct hsi_client *cl = msg->cl;
+       struct ssi_protocol *ssi = hsi_client_drvdata(cl);
+       struct sk_buff *skb;
+
+       if (msg->status == HSI_STATUS_ERROR) {
+               dev_err(&cl->device, "RX data error\n");
+               ssip_free_data(msg);
+               ssip_error(cl);
+               return;
+       }
+       del_timer(&ssi->rx_wd); /* FIXME: Revisit */
+       skb = msg->context;
+       ssip_pn_rx(skb);
+       hsi_free_msg(msg);
+}
+
+static void ssip_rx_bootinforeq(struct hsi_client *cl, u32 cmd)
+{
+       struct ssi_protocol *ssi = hsi_client_drvdata(cl);
+       struct hsi_msg *msg;
+
+       /* Workaroud: Ignore CMT Loader message leftover */
+       if (cmd == SSIP_CMT_LOADER_SYNC)
+               return;
+
+       switch (ssi->main_state) {
+       case ACTIVE:
+               dev_err(&cl->device, "Boot info req on active state\n");
+               ssip_error(cl);
+               /* Fall through */
+       case INIT:
+               spin_lock(&ssi->lock);
+               ssi->main_state = HANDSHAKE;
+               if (!ssi->waketest) {
+                       ssi->waketest = 1;
+                       ssi_waketest(cl, 1); /* FIXME: To be removed */
+               }
+               /* Start boot handshake watchdog */
+               mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
+               spin_unlock(&ssi->lock);
+               dev_dbg(&cl->device, "Send BOOTINFO_RESP\n");
+               if (SSIP_DATA_VERSION(cmd) != SSIP_LOCAL_VERID)
+                       dev_warn(&cl->device, "boot info req verid mismatch\n");
+               msg = ssip_claim_cmd(ssi);
+               ssip_set_cmd(msg, SSIP_BOOTINFO_RESP_CMD(SSIP_LOCAL_VERID));
+               msg->complete = ssip_release_cmd;
+               hsi_async_write(cl, msg);
+               break;
+       case HANDSHAKE:
+               /* Ignore */
+               break;
+       default:
+               dev_dbg(&cl->device, "Wrong state M(%d)\n", ssi->main_state);
+               break;
+       }
+}
+
+static void ssip_rx_bootinforesp(struct hsi_client *cl, u32 cmd)
+{
+       struct ssi_protocol *ssi = hsi_client_drvdata(cl);
+
+       if (SSIP_DATA_VERSION(cmd) != SSIP_LOCAL_VERID)
+               dev_warn(&cl->device, "boot info resp verid mismatch\n");
+
+       spin_lock(&ssi->lock);
+       if (ssi->main_state != ACTIVE)
+               /* Use tx_wd as a boot watchdog in non ACTIVE state */
+               mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
+       else
+               dev_dbg(&cl->device, "boot info resp ignored M(%d)\n",
+                                                       ssi->main_state);
+       spin_unlock(&ssi->lock);
+}
+
+static void ssip_rx_waketest(struct hsi_client *cl, u32 cmd)
+{
+       struct ssi_protocol *ssi = hsi_client_drvdata(cl);
+       unsigned int wkres = SSIP_PAYLOAD(cmd);
+
+       spin_lock(&ssi->lock);
+       if (ssi->main_state != HANDSHAKE) {
+               dev_dbg(&cl->device, "wake lines test ignored M(%d)\n",
+                                                       ssi->main_state);
+               spin_unlock(&ssi->lock);
+               return;
+       }
+       if (ssi->waketest) {
+               ssi->waketest = 0;
+               ssi_waketest(cl, 0); /* FIXME: To be removed */
+       }
+       ssi->main_state = ACTIVE;
+       del_timer(&ssi->tx_wd); /* Stop boot handshake timer */
+       spin_unlock(&ssi->lock);
+
+       dev_notice(&cl->device, "WAKELINES TEST %s\n",
+                               wkres & SSIP_WAKETEST_FAILED ? "FAILED" : "OK");
+       if (wkres & SSIP_WAKETEST_FAILED) {
+               ssip_error(cl);
+               return;
+       }
+       dev_dbg(&cl->device, "CMT is ONLINE\n");
+       netif_wake_queue(ssi->netdev);
+       netif_carrier_on(ssi->netdev);
+}
+
+static void ssip_rx_ready(struct hsi_client *cl)
+{
+       struct ssi_protocol *ssi = hsi_client_drvdata(cl);
+
+       spin_lock(&ssi->lock);
+       if (unlikely(ssi->main_state != ACTIVE)) {
+               dev_dbg(&cl->device, "READY on wrong state: S(%d) M(%d)\n",
+                                       ssi->send_state, ssi->main_state);
+               spin_unlock(&ssi->lock);
+               return;
+       }
+       if (ssi->send_state != WAIT4READY) {
+               dev_dbg(&cl->device, "Ignore spurious READY command\n");
+               spin_unlock(&ssi->lock);
+               return;
+       }
+       ssip_set_txstate(ssi, SEND_READY);
+       spin_unlock(&ssi->lock);
+       ssip_xmit(cl);
+}
+
+static void ssip_rx_strans(struct hsi_client *cl, u32 cmd)
+{
+       struct ssi_protocol *ssi = hsi_client_drvdata(cl);
+       struct sk_buff *skb;
+       struct hsi_msg *msg;
+       int len = SSIP_PDU_LENGTH(cmd);
+
+       dev_dbg(&cl->device, "RX strans: %d frames\n", len);
+       spin_lock(&ssi->lock);
+       if (unlikely(ssi->main_state != ACTIVE)) {
+               dev_err(&cl->device, "START TRANS wrong state: S(%d) M(%d)\n",
+                                       ssi->send_state, ssi->main_state);
+               spin_unlock(&ssi->lock);
+               return;
+       }
+       ssip_set_rxstate(ssi, RECEIVING);
+       if (unlikely(SSIP_MSG_ID(cmd) != ssi->rxid)) {
+               dev_err(&cl->device, "START TRANS id %d expeceted %d\n",
+                                       SSIP_MSG_ID(cmd), ssi->rxid);
+               spin_unlock(&ssi->lock);
+               goto out1;
+       }
+       ssi->rxid++;
+       spin_unlock(&ssi->lock);
+       skb = netdev_alloc_skb(ssi->netdev, len * 4);
+       if (unlikely(!skb)) {
+               dev_err(&cl->device, "No memory for rx skb\n");
+               goto out1;
+       }
+       skb->dev = ssi->netdev;
+       skb_put(skb, len * 4);
+       msg = ssip_alloc_data(ssi, skb, GFP_ATOMIC);
+       if (unlikely(!msg)) {
+               dev_err(&cl->device, "No memory for RX data msg\n");
+               goto out2;
+       }
+       msg->complete = ssip_rx_data_complete;
+       hsi_async_read(cl, msg);
+
+       return;
+out2:
+       dev_kfree_skb(skb);
+out1:
+       ssip_error(cl);
+}
+
+static void ssip_rxcmd_complete(struct hsi_msg *msg)
+{
+       struct hsi_client *cl = msg->cl;
+       u32 cmd = ssip_get_cmd(msg);
+       unsigned int cmdid = SSIP_COMMAND(cmd);
+
+       if (msg->status == HSI_STATUS_ERROR) {
+               dev_err(&cl->device, "RX error detected\n");
+               ssip_release_cmd(msg);
+               ssip_error(cl);
+               return;
+       }
+       hsi_async_read(cl, msg);
+       dev_dbg(&cl->device, "RX cmd: 0x%08x\n", cmd);
+       switch (cmdid) {
+       case SSIP_SW_BREAK:
+               /* Ignored */
+               break;
+       case SSIP_BOOTINFO_REQ:
+               ssip_rx_bootinforeq(cl, cmd);
+               break;
+       case SSIP_BOOTINFO_RESP:
+               ssip_rx_bootinforesp(cl, cmd);
+               break;
+       case SSIP_WAKETEST_RESULT:
+               ssip_rx_waketest(cl, cmd);
+               break;
+       case SSIP_START_TRANS:
+               ssip_rx_strans(cl, cmd);
+               break;
+       case SSIP_READY:
+               ssip_rx_ready(cl);
+               break;
+       default:
+               dev_warn(&cl->device, "command 0x%08x not supported\n", cmd);
+               break;
+       }
+}
+
+static void ssip_swbreak_complete(struct hsi_msg *msg)
+{
+       struct hsi_client *cl = msg->cl;
+       struct ssi_protocol *ssi = hsi_client_drvdata(cl);
+
+       ssip_release_cmd(msg);
+       spin_lock(&ssi->lock);
+       if (list_empty(&ssi->txqueue)) {
+               if (atomic_read(&ssi->tx_usecnt)) {
+                       ssip_set_txstate(ssi, SEND_READY);
+               } else {
+                       ssip_set_txstate(ssi, SEND_IDLE);
+                       hsi_stop_tx(cl);
+               }
+               spin_unlock(&ssi->lock);
+       } else {
+               spin_unlock(&ssi->lock);
+               ssip_xmit(cl);
+       }
+       netif_wake_queue(ssi->netdev);
+}
+
+static void ssip_tx_data_complete(struct hsi_msg *msg)
+{
+       struct hsi_client *cl = msg->cl;
+       struct ssi_protocol *ssi = hsi_client_drvdata(cl);
+       struct hsi_msg *cmsg;
+
+       if (msg->status == HSI_STATUS_ERROR) {
+               dev_err(&cl->device, "TX data error\n");
+               ssip_error(cl);
+               goto out;
+       }
+       spin_lock(&ssi->lock);
+       if (list_empty(&ssi->txqueue)) {
+               ssip_set_txstate(ssi, SENDING_SWBREAK);
+               spin_unlock(&ssi->lock);
+               cmsg = ssip_claim_cmd(ssi);
+               ssip_set_cmd(cmsg, SSIP_SWBREAK_CMD);
+               cmsg->complete = ssip_swbreak_complete;
+               dev_dbg(&cl->device, "Send SWBREAK\n");
+               hsi_async_write(cl, cmsg);
+       } else {
+               spin_unlock(&ssi->lock);
+               ssip_xmit(cl);
+       }
+out:
+       ssip_free_data(msg);
+}
+
+void ssip_port_event(struct hsi_client *cl, unsigned long event)
+{
+       switch (event) {
+       case HSI_EVENT_START_RX:
+               ssip_start_rx(cl);
+               break;
+       case HSI_EVENT_STOP_RX:
+               ssip_stop_rx(cl);
+               break;
+       default:
+               return;
+       }
+}
+
+static int ssip_pn_open(struct net_device *dev)
+{
+       struct hsi_client *cl = to_hsi_client(dev->dev.parent);
+       struct ssi_protocol *ssi = hsi_client_drvdata(cl);
+       int err;
+
+       err = hsi_claim_port(cl, 1);
+       if (err < 0) {
+               dev_err(&cl->device, "SSI port already claimed\n");
+               return err;
+       }
+       err = hsi_register_port_event(cl, ssip_port_event);
+       if (err < 0) {
+               dev_err(&cl->device, "Register HSI port event failed (%d)\n",
+                       err);
+               return err;
+       }
+       dev_dbg(&cl->device, "Configuring SSI port\n");
+       hsi_setup(cl);
+       spin_lock_bh(&ssi->lock);
+       if (!ssi->waketest) {
+               ssi->waketest = 1;
+               ssi_waketest(cl, 1); /* FIXME: To be removed */
+       }
+       ssi->main_state = INIT;
+       spin_unlock_bh(&ssi->lock);
+
+       return 0;
+}
+
+static int ssip_pn_stop(struct net_device *dev)
+{
+       struct hsi_client *cl = to_hsi_client(dev->dev.parent);
+
+       ssip_reset(cl);
+       hsi_unregister_port_event(cl);
+       hsi_release_port(cl);
+
+       return 0;
+}
+
+static int ssip_pn_set_mtu(struct net_device *dev, int new_mtu)
+{
+       if (new_mtu > SSIP_MAX_MTU || new_mtu < PHONET_MIN_MTU)
+               return -EINVAL;
+       dev->mtu = new_mtu;
+
+       return 0;
+}
+
+static int ssip_pn_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+       struct hsi_client *cl = to_hsi_client(dev->dev.parent);
+       struct ssi_protocol *ssi = hsi_client_drvdata(cl);
+       struct hsi_msg *msg;
+
+       if ((skb->protocol != htons(ETH_P_PHONET)) ||
+                                       (skb->len < SSIP_MIN_PN_HDR))
+               goto drop;
+       /* Pad to 32-bits - FIXME: Revisit*/
+       if ((skb->len & 3) && skb_pad(skb, 4 - (skb->len & 3)))
+               goto drop;
+
+       /*
+        * Modem sends Phonet messages over SSI with its own endianess...
+        * Assume that modem has the same endianess as we do.
+        */
+       if (skb_cow_head(skb, 0))
+               goto drop;
+
+       /* length field is exchanged in network byte order */
+       ((u16 *)skb->data)[2] = htons(((u16 *)skb->data)[2]);
+
+       msg = ssip_alloc_data(ssi, skb, GFP_ATOMIC);
+       if (!msg) {
+               dev_dbg(&cl->device, "Dropping tx data: No memory\n");
+               goto drop;
+       }
+       msg->complete = ssip_tx_data_complete;
+
+       spin_lock_bh(&ssi->lock);
+       if (unlikely(ssi->main_state != ACTIVE)) {
+               spin_unlock_bh(&ssi->lock);
+               dev_dbg(&cl->device, "Dropping tx data: CMT is OFFLINE\n");
+               goto drop2;
+       }
+       list_add_tail(&msg->link, &ssi->txqueue);
+       ssi->txqueue_len++;
+       if (dev->tx_queue_len < ssi->txqueue_len) {
+               dev_info(&cl->device, "TX queue full %d\n", ssi->txqueue_len);
+               netif_stop_queue(dev);
+       }
+       if (ssi->send_state == SEND_IDLE) {
+               ssip_set_txstate(ssi, WAIT4READY);
+               spin_unlock_bh(&ssi->lock);
+               dev_dbg(&cl->device, "Start TX qlen %d\n", ssi->txqueue_len);
+               hsi_start_tx(cl);
+       } else if (ssi->send_state == SEND_READY) {
+               /* Needed for cmt-speech workaround */
+               dev_dbg(&cl->device, "Start TX on SEND READY qlen %d\n",
+                                                       ssi->txqueue_len);
+               spin_unlock_bh(&ssi->lock);
+               ssip_xmit(cl);
+       } else {
+               spin_unlock_bh(&ssi->lock);
+       }
+       dev->stats.tx_packets++;
+       dev->stats.tx_bytes += skb->len;
+
+       return 0;
+drop2:
+       hsi_free_msg(msg);
+drop:
+       dev->stats.tx_dropped++;
+       dev_kfree_skb(skb);
+
+       return 0;
+}
+
+/* CMT reset event handler */
+void ssip_reset_event(struct hsi_client *master)
+{
+       struct ssi_protocol *ssi = hsi_client_drvdata(master);
+       dev_err(&ssi->cl->device, "CMT reset detected!\n");
+       ssip_error(ssi->cl);
+}
+EXPORT_SYMBOL_GPL(ssip_reset_event);
+
+static const struct net_device_ops ssip_pn_ops = {
+       .ndo_open       = ssip_pn_open,
+       .ndo_stop       = ssip_pn_stop,
+       .ndo_start_xmit = ssip_pn_xmit,
+       .ndo_change_mtu = ssip_pn_set_mtu,
+};
+
+static void ssip_pn_setup(struct net_device *dev)
+{
+       dev->features           = 0;
+       dev->netdev_ops         = &ssip_pn_ops;
+       dev->type               = ARPHRD_PHONET;
+       dev->flags              = IFF_POINTOPOINT | IFF_NOARP;
+       dev->mtu                = SSIP_DEFAULT_MTU;
+       dev->hard_header_len    = 1;
+       dev->dev_addr[0]        = PN_MEDIA_SOS;
+       dev->addr_len           = 1;
+       dev->tx_queue_len       = SSIP_TXQUEUE_LEN;
+
+       dev->destructor         = free_netdev;
+       dev->header_ops         = &phonet_header_ops;
+}
+
+static int ssi_protocol_probe(struct device *dev)
+{
+       static const char ifname[] = "phonet%d";
+       struct hsi_client *cl = to_hsi_client(dev);
+       struct ssi_protocol *ssi;
+       int err;
+
+       ssi = kzalloc(sizeof(*ssi), GFP_KERNEL);
+       if (!ssi) {
+               dev_err(dev, "No memory for ssi protocol\n");
+               return -ENOMEM;
+       }
+
+       spin_lock_init(&ssi->lock);
+       init_timer_deferrable(&ssi->rx_wd);
+       init_timer_deferrable(&ssi->tx_wd);
+       init_timer(&ssi->keep_alive);
+       ssi->rx_wd.data = (unsigned long)cl;
+       ssi->rx_wd.function = ssip_wd;
+       ssi->tx_wd.data = (unsigned long)cl;
+       ssi->tx_wd.function = ssip_wd;
+       ssi->keep_alive.data = (unsigned long)cl;
+       ssi->keep_alive.function = ssip_keep_alive;
+       INIT_LIST_HEAD(&ssi->txqueue);
+       INIT_LIST_HEAD(&ssi->cmdqueue);
+       atomic_set(&ssi->tx_usecnt, 0);
+       hsi_client_set_drvdata(cl, ssi);
+       ssi->cl = cl;
+
+       ssi->channel_id_cmd = hsi_get_channel_id_by_name(cl, "mcsaab-control");
+       if (ssi->channel_id_cmd < 0) {
+               err = ssi->channel_id_cmd;
+               dev_err(dev, "Could not get cmd channel (%d)\n", err);
+               goto out;
+       }
+
+       ssi->channel_id_data = hsi_get_channel_id_by_name(cl, "mcsaab-data");
+       if (ssi->channel_id_data < 0) {
+               err = ssi->channel_id_data;
+               dev_err(dev, "Could not get data channel (%d)\n", err);
+               goto out;
+       }
+
+       err = ssip_alloc_cmds(ssi);
+       if (err < 0) {
+               dev_err(dev, "No memory for commands\n");
+               goto out;
+       }
+
+       ssi->netdev = alloc_netdev(0, ifname, ssip_pn_setup);
+       if (!ssi->netdev) {
+               dev_err(dev, "No memory for netdev\n");
+               err = -ENOMEM;
+               goto out1;
+       }
+
+       SET_NETDEV_DEV(ssi->netdev, dev);
+       netif_carrier_off(ssi->netdev);
+       err = register_netdev(ssi->netdev);
+       if (err < 0) {
+               dev_err(dev, "Register netdev failed (%d)\n", err);
+               goto out2;
+       }
+
+       list_add(&ssi->link, &ssip_list);
+
+       dev_dbg(dev, "channel configuration: cmd=%d, data=%d\n",
+               ssi->channel_id_cmd, ssi->channel_id_data);
+
+       return 0;
+out2:
+       free_netdev(ssi->netdev);
+out1:
+       ssip_free_cmds(ssi);
+out:
+       kfree(ssi);
+
+       return err;
+}
+
+static int ssi_protocol_remove(struct device *dev)
+{
+       struct hsi_client *cl = to_hsi_client(dev);
+       struct ssi_protocol *ssi = hsi_client_drvdata(cl);
+
+       list_del(&ssi->link);
+       unregister_netdev(ssi->netdev);
+       ssip_free_cmds(ssi);
+       hsi_client_set_drvdata(cl, NULL);
+       kfree(ssi);
+
+       return 0;
+}
+
+static struct hsi_client_driver ssip_driver = {
+       .driver = {
+               .name   = "ssi-protocol",
+               .owner  = THIS_MODULE,
+               .probe  = ssi_protocol_probe,
+               .remove = ssi_protocol_remove,
+       },
+};
+
+static int __init ssip_init(void)
+{
+       pr_info("SSI protocol aka McSAAB added\n");
+
+       return hsi_register_client_driver(&ssip_driver);
+}
+module_init(ssip_init);
+
+static void __exit ssip_exit(void)
+{
+       hsi_unregister_client_driver(&ssip_driver);
+       pr_info("SSI protocol driver removed\n");
+}
+module_exit(ssip_exit);
+
+MODULE_ALIAS("hsi:ssi-protocol");
+MODULE_AUTHOR("Carlos Chinea <carlos.chinea@nokia.com>");
+MODULE_AUTHOR("Remi Denis-Courmont <remi.denis-courmont@nokia.com>");
+MODULE_DESCRIPTION("SSI protocol improved aka McSAAB");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/hsi/ssi_protocol.h b/include/linux/hsi/ssi_protocol.h
new file mode 100644 (file)
index 0000000..1433651
--- /dev/null
@@ -0,0 +1,42 @@
+/*
+ * ssip_slave.h
+ *
+ * SSIP slave support header file
+ *
+ * Copyright (C) 2010 Nokia Corporation. All rights reserved.
+ *
+ * Contact: Carlos Chinea <carlos.chinea@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#ifndef __LINUX_SSIP_SLAVE_H__
+#define __LINUX_SSIP_SLAVE_H__
+
+#include <linux/hsi/hsi.h>
+
+static inline void ssip_slave_put_master(struct hsi_client *master)
+{
+}
+
+struct hsi_client *ssip_slave_get_master(struct hsi_client *slave);
+int ssip_slave_start_tx(struct hsi_client *master);
+int ssip_slave_stop_tx(struct hsi_client *master);
+void ssip_reset_event(struct hsi_client *master);
+
+int ssip_slave_running(struct hsi_client *master);
+
+#endif /* __LINUX_SSIP_SLAVE_H__ */
+