/* arch/arm/mach-msm/smd.c
   *
   * Copyright (C) 2007 Google, Inc.
   * Author: Brian Swetland <swetland@google.com>
   *
   * This software is licensed under the terms of the GNU General Public
   * License version 2, as published by the Free Software Foundation, and
   * may be copied, distributed, and modified under those terms.
   *
   * 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.
   *
   */
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #include <linux/platform_device.h>
  #include <linux/module.h>
  #include <linux/fs.h>
  #include <linux/cdev.h>
  #include <linux/device.h>
  #include <linux/wait.h>
  #include <linux/interrupt.h>
  #include <linux/irq.h>
  #include <linux/list.h>
  #include <linux/slab.h>
  #include <linux/debugfs.h>
  #include <linux/delay.h>
  
  #include <mach/msm_smd.h>
  
  #include "smd_private.h"
  #include "proc_comm.h"
  
  #if defined(CONFIG_ARCH_QSD8X50)
  #define CONFIG_QDSP6 1
  #endif
  
  #define MODULE_NAME "msm_smd"
  
  enum {
  	MSM_SMD_DEBUG = 1U << 0,
  	MSM_SMSM_DEBUG = 1U << 0,
  };
  
  static int msm_smd_debug_mask;
  
  struct shared_info {
  	int ready;
  	void __iomem *state;
  };
  
  static unsigned dummy_state[SMSM_STATE_COUNT];
  
  static struct shared_info smd_info = {
  	/* FIXME: not a real __iomem pointer */
  	.state = &dummy_state,
  };
  
  module_param_named(debug_mask, msm_smd_debug_mask,
  		   int, S_IRUGO | S_IWUSR | S_IWGRP);
  
  static unsigned last_heap_free = 0xffffffff;
  
  static inline void notify_other_smsm(void)
  {
  	msm_a2m_int(5);
  #ifdef CONFIG_QDSP6
  	msm_a2m_int(8);
  #endif
  }
  
  static inline void notify_modem_smd(void)
  {
  	msm_a2m_int(0);
  }
  
  static inline void notify_dsp_smd(void)
  {
  	msm_a2m_int(8);
  }
  
  static void smd_diag(void)
  {
  	char *x;
  
  	x = smem_find(ID_DIAG_ERR_MSG, SZ_DIAG_ERR_MSG);
  	if (x != 0) {
  		x[SZ_DIAG_ERR_MSG - 1] = 0;
  		pr_debug("DIAG '%s'
  ", x);
  	}
  }
  
  /* call when SMSM_RESET flag is set in the A9's smsm_state */
  static void handle_modem_crash(void)
  {
  	pr_err("ARM9 has CRASHED
  ");
  	smd_diag();
  
  	/* in this case the modem or watchdog should reboot us */
  	for (;;)
  		;
  }
  
  uint32_t raw_smsm_get_state(enum smsm_state_item item)
  {
  	return readl(smd_info.state + item * 4);
  }
  
  static int check_for_modem_crash(void)
  {
  	if (raw_smsm_get_state(SMSM_STATE_MODEM) & SMSM_RESET) {
  		handle_modem_crash();
  		return -1;
  	}
  	return 0;
  }
  
  /* the spinlock is used to synchronize between the
   * irq handler and code that mutates the channel
   * list or fiddles with channel state
   */
  DEFINE_SPINLOCK(smd_lock);
  DEFINE_SPINLOCK(smem_lock);
  
  /* the mutex is used during open() and close()
   * operations to avoid races while creating or
   * destroying smd_channel structures
   */
  static DEFINE_MUTEX(smd_creation_mutex);
  
  static int smd_initialized;
  
  LIST_HEAD(smd_ch_closed_list);
  LIST_HEAD(smd_ch_list_modem);
  LIST_HEAD(smd_ch_list_dsp);
  
  static unsigned char smd_ch_allocated[64];
  static struct work_struct probe_work;
  
  /* how many bytes are available for reading */
  static int smd_stream_read_avail(struct smd_channel *ch)
  {
  	return (ch->recv->head - ch->recv->tail) & ch->fifo_mask;
  }
  
  /* how many bytes we are free to write */
  static int smd_stream_write_avail(struct smd_channel *ch)
  {
  	return ch->fifo_mask -
  		((ch->send->head - ch->send->tail) & ch->fifo_mask);
  }
  
  static int smd_packet_read_avail(struct smd_channel *ch)
  {
  	if (ch->current_packet) {
  		int n = smd_stream_read_avail(ch);
  		if (n > ch->current_packet)
  			n = ch->current_packet;
  		return n;
  	} else {
  		return 0;
  	}
  }
  
  static int smd_packet_write_avail(struct smd_channel *ch)
  {
  	int n = smd_stream_write_avail(ch);
  	return n > SMD_HEADER_SIZE ? n - SMD_HEADER_SIZE : 0;
  }
  
  static int ch_is_open(struct smd_channel *ch)
  {
  	return (ch->recv->state == SMD_SS_OPENED) &&
  		(ch->send->state == SMD_SS_OPENED);
  }
  
  /* provide a pointer and length to readable data in the fifo */
  static unsigned ch_read_buffer(struct smd_channel *ch, void **ptr)
  {
  	unsigned head = ch->recv->head;
  	unsigned tail = ch->recv->tail;
  	*ptr = (void *) (ch->recv_data + tail);
  
  	if (tail <= head)
  		return head - tail;
  	else
  		return ch->fifo_size - tail;
  }
  
  /* advance the fifo read pointer after data from ch_read_buffer is consumed */
  static void ch_read_done(struct smd_channel *ch, unsigned count)
  {
  	BUG_ON(count > smd_stream_read_avail(ch));
  	ch->recv->tail = (ch->recv->tail + count) & ch->fifo_mask;
  	ch->send->fTAIL = 1;
  }
  
  /* basic read interface to ch_read_{buffer,done} used
   * by smd_*_read() and update_packet_state()
   * will read-and-discard if the _data pointer is null
   */
  static int ch_read(struct smd_channel *ch, void *_data, int len)
  {
  	void *ptr;
  	unsigned n;
  	unsigned char *data = _data;
  	int orig_len = len;
  
  	while (len > 0) {
  		n = ch_read_buffer(ch, &ptr);
  		if (n == 0)
  			break;
  
  		if (n > len)
  			n = len;
  		if (_data)
  			memcpy(data, ptr, n);
  
  		data += n;
  		len -= n;
  		ch_read_done(ch, n);
  	}
  
  	return orig_len - len;
  }
  
  static void update_stream_state(struct smd_channel *ch)
  {
  	/* streams have no special state requiring updating */
  }
  
  static void update_packet_state(struct smd_channel *ch)
  {
  	unsigned hdr[5];
  	int r;
  
  	/* can't do anything if we're in the middle of a packet */
  	if (ch->current_packet != 0)
  		return;
  
  	/* don't bother unless we can get the full header */
  	if (smd_stream_read_avail(ch) < SMD_HEADER_SIZE)
  		return;
  
  	r = ch_read(ch, hdr, SMD_HEADER_SIZE);
  	BUG_ON(r != SMD_HEADER_SIZE);
  
  	ch->current_packet = hdr[0];
  }
  
  /* provide a pointer and length to next free space in the fifo */
  static unsigned ch_write_buffer(struct smd_channel *ch, void **ptr)
  {
  	unsigned head = ch->send->head;
  	unsigned tail = ch->send->tail;
  	*ptr = (void *) (ch->send_data + head);
  
  	if (head < tail) {
  		return tail - head - 1;
  	} else {
  		if (tail == 0)
  			return ch->fifo_size - head - 1;
  		else
  			return ch->fifo_size - head;
  	}
  }
  
  /* advace the fifo write pointer after freespace
   * from ch_write_buffer is filled
   */
  static void ch_write_done(struct smd_channel *ch, unsigned count)
  {
  	BUG_ON(count > smd_stream_write_avail(ch));
  	ch->send->head = (ch->send->head + count) & ch->fifo_mask;
  	ch->send->fHEAD = 1;
  }
  
  static void ch_set_state(struct smd_channel *ch, unsigned n)
  {
  	if (n == SMD_SS_OPENED) {
  		ch->send->fDSR = 1;
  		ch->send->fCTS = 1;
  		ch->send->fCD = 1;
  	} else {
  		ch->send->fDSR = 0;
  		ch->send->fCTS = 0;
  		ch->send->fCD = 0;
  	}
  	ch->send->state = n;
  	ch->send->fSTATE = 1;
  	ch->notify_other_cpu();
  }
  
  static void do_smd_probe(void)
  {
  	struct smem_shared *shared = (void *) MSM_SHARED_RAM_BASE;
  	if (shared->heap_info.free_offset != last_heap_free) {
  		last_heap_free = shared->heap_info.free_offset;
  		schedule_work(&probe_work);
  	}
  }
  
  static void smd_state_change(struct smd_channel *ch,
  			     unsigned last, unsigned next)
  {
  	ch->last_state = next;
  
  	pr_debug("ch %d %d -> %d
  ", ch->n, last, next);
  
  	switch (next) {
  	case SMD_SS_OPENING:
  		ch->recv->tail = 0;
  	case SMD_SS_OPENED:
  		if (ch->send->state != SMD_SS_OPENED)
  			ch_set_state(ch, SMD_SS_OPENED);
  		ch->notify(ch->priv, SMD_EVENT_OPEN);
  		break;
  	case SMD_SS_FLUSHING:
  	case SMD_SS_RESET:
  		/* we should force them to close? */
  	default:
  		ch->notify(ch->priv, SMD_EVENT_CLOSE);
  	}
  }
  
  static void handle_smd_irq(struct list_head *list, void (*notify)(void))
  {
  	unsigned long flags;
  	struct smd_channel *ch;
  	int do_notify = 0;
  	unsigned ch_flags;
  	unsigned tmp;
  
  	spin_lock_irqsave(&smd_lock, flags);
  	list_for_each_entry(ch, list, ch_list) {
  		ch_flags = 0;
  		if (ch_is_open(ch)) {
  			if (ch->recv->fHEAD) {
  				ch->recv->fHEAD = 0;
  				ch_flags |= 1;
  				do_notify |= 1;
  			}
  			if (ch->recv->fTAIL) {
  				ch->recv->fTAIL = 0;
  				ch_flags |= 2;
  				do_notify |= 1;
  			}
  			if (ch->recv->fSTATE) {
  				ch->recv->fSTATE = 0;
  				ch_flags |= 4;
  				do_notify |= 1;
  			}
  		}
  		tmp = ch->recv->state;
  		if (tmp != ch->last_state)
  			smd_state_change(ch, ch->last_state, tmp);
  		if (ch_flags) {
  			ch->update_state(ch);
  			ch->notify(ch->priv, SMD_EVENT_DATA);
  		}
  	}
  	if (do_notify)
  		notify();
  	spin_unlock_irqrestore(&smd_lock, flags);
  	do_smd_probe();
  }
  
  static irqreturn_t smd_modem_irq_handler(int irq, void *data)
  {
  	handle_smd_irq(&smd_ch_list_modem, notify_modem_smd);
  	return IRQ_HANDLED;
  }
  
  #if defined(CONFIG_QDSP6)
  static irqreturn_t smd_dsp_irq_handler(int irq, void *data)
  {
  	handle_smd_irq(&smd_ch_list_dsp, notify_dsp_smd);
  	return IRQ_HANDLED;
  }
  #endif
  
  static void smd_fake_irq_handler(unsigned long arg)
  {
  	handle_smd_irq(&smd_ch_list_modem, notify_modem_smd);
  	handle_smd_irq(&smd_ch_list_dsp, notify_dsp_smd);
  }
  
  static DECLARE_TASKLET(smd_fake_irq_tasklet, smd_fake_irq_handler, 0);
  
  static inline int smd_need_int(struct smd_channel *ch)
  {
  	if (ch_is_open(ch)) {
  		if (ch->recv->fHEAD || ch->recv->fTAIL || ch->recv->fSTATE)
  			return 1;
  		if (ch->recv->state != ch->last_state)
  			return 1;
  	}
  	return 0;
  }
  
  void smd_sleep_exit(void)
  {
  	unsigned long flags;
  	struct smd_channel *ch;
  	int need_int = 0;
  
  	spin_lock_irqsave(&smd_lock, flags);
  	list_for_each_entry(ch, &smd_ch_list_modem, ch_list) {
  		if (smd_need_int(ch)) {
  			need_int = 1;
  			break;
  		}
  	}
  	list_for_each_entry(ch, &smd_ch_list_dsp, ch_list) {
  		if (smd_need_int(ch)) {
  			need_int = 1;
  			break;
  		}
  	}
  	spin_unlock_irqrestore(&smd_lock, flags);
  	do_smd_probe();
  
  	if (need_int) {
  		if (msm_smd_debug_mask & MSM_SMD_DEBUG)
  			pr_info("smd_sleep_exit need interrupt
  ");
  		tasklet_schedule(&smd_fake_irq_tasklet);
  	}
  }
  
  
  void smd_kick(smd_channel_t *ch)
  {
  	unsigned long flags;
  	unsigned tmp;
  
  	spin_lock_irqsave(&smd_lock, flags);
  	ch->update_state(ch);
  	tmp = ch->recv->state;
  	if (tmp != ch->last_state) {
  		ch->last_state = tmp;
  		if (tmp == SMD_SS_OPENED)
  			ch->notify(ch->priv, SMD_EVENT_OPEN);
  		else
  			ch->notify(ch->priv, SMD_EVENT_CLOSE);
  	}
  	ch->notify(ch->priv, SMD_EVENT_DATA);
  	ch->notify_other_cpu();
  	spin_unlock_irqrestore(&smd_lock, flags);
  }
  
  static int smd_is_packet(int chn, unsigned type)
  {
  	type &= SMD_KIND_MASK;
  	if (type == SMD_KIND_PACKET)
  		return 1;
  	if (type == SMD_KIND_STREAM)
  		return 0;
  
  	/* older AMSS reports SMD_KIND_UNKNOWN always */
  	if ((chn > 4) || (chn == 1))
  		return 1;
  	else
  		return 0;
  }
  
  static int smd_stream_write(smd_channel_t *ch, const void *_data, int len)
  {
  	void *ptr;
  	const unsigned char *buf = _data;
  	unsigned xfer;
  	int orig_len = len;
  
  	if (len < 0)
  		return -EINVAL;
  
  	while ((xfer = ch_write_buffer(ch, &ptr)) != 0) {
  		if (!ch_is_open(ch))
  			break;
  		if (xfer > len)
  			xfer = len;
  		memcpy(ptr, buf, xfer);
  		ch_write_done(ch, xfer);
  		len -= xfer;
  		buf += xfer;
  		if (len == 0)
  			break;
  	}
  
  	ch->notify_other_cpu();
  
  	return orig_len - len;
  }
  
  static int smd_packet_write(smd_channel_t *ch, const void *_data, int len)
  {
  	unsigned hdr[5];
  
  	if (len < 0)
  		return -EINVAL;
  
  	if (smd_stream_write_avail(ch) < (len + SMD_HEADER_SIZE))
  		return -ENOMEM;
  
  	hdr[0] = len;
  	hdr[1] = hdr[2] = hdr[3] = hdr[4] = 0;
  
  	smd_stream_write(ch, hdr, sizeof(hdr));
  	smd_stream_write(ch, _data, len);
  
  	return len;
  }
  
  static int smd_stream_read(smd_channel_t *ch, void *data, int len)
  {
  	int r;
  
  	if (len < 0)
  		return -EINVAL;
  
  	r = ch_read(ch, data, len);
  	if (r > 0)
  		ch->notify_other_cpu();
  
  	return r;
  }
  
  static int smd_packet_read(smd_channel_t *ch, void *data, int len)
  {
  	unsigned long flags;
  	int r;
  
  	if (len < 0)
  		return -EINVAL;
  
  	if (len > ch->current_packet)
  		len = ch->current_packet;
  
  	r = ch_read(ch, data, len);
  	if (r > 0)
  		ch->notify_other_cpu();
  
  	spin_lock_irqsave(&smd_lock, flags);
  	ch->current_packet -= r;
  	update_packet_state(ch);
  	spin_unlock_irqrestore(&smd_lock, flags);
  
  	return r;
  }
  
  static int smd_alloc_channel(const char *name, uint32_t cid, uint32_t type)
  {
  	struct smd_channel *ch;
  
  	ch = kzalloc(sizeof(struct smd_channel), GFP_KERNEL);
  	if (ch == 0) {
  		pr_err("smd_alloc_channel() out of memory
  ");
  		return -1;
  	}
  	ch->n = cid;
  
  	if (_smd_alloc_channel(ch)) {
  		kfree(ch);
  		return -1;
  	}
  
  	ch->fifo_mask = ch->fifo_size - 1;
  	ch->type = type;
  
  	if ((type & SMD_TYPE_MASK) == SMD_TYPE_APPS_MODEM)
  		ch->notify_other_cpu = notify_modem_smd;
  	else
  		ch->notify_other_cpu = notify_dsp_smd;
  
  	if (smd_is_packet(cid, type)) {
  		ch->read = smd_packet_read;
  		ch->write = smd_packet_write;
  		ch->read_avail = smd_packet_read_avail;
  		ch->write_avail = smd_packet_write_avail;
  		ch->update_state = update_packet_state;
  	} else {
  		ch->read = smd_stream_read;
  		ch->write = smd_stream_write;
  		ch->read_avail = smd_stream_read_avail;
  		ch->write_avail = smd_stream_write_avail;
  		ch->update_state = update_stream_state;
  	}
  
  	if ((type & 0xff) == 0)
  		memcpy(ch->name, "SMD_", 4);
  	else
  		memcpy(ch->name, "DSP_", 4);
  	memcpy(ch->name + 4, name, 20);
  	ch->name[23] = 0;
  	ch->pdev.name = ch->name;
  	ch->pdev.id = -1;
  
  	pr_debug("smd_alloc_channel() cid=%02d size=%05d '%s'
  ",
  		ch->n, ch->fifo_size, ch->name);
  
  	mutex_lock(&smd_creation_mutex);
  	list_add(&ch->ch_list, &smd_ch_closed_list);
  	mutex_unlock(&smd_creation_mutex);
  
  	platform_device_register(&ch->pdev);
  	return 0;
  }
  
  static void smd_channel_probe_worker(struct work_struct *work)
  {
  	struct smd_alloc_elm *shared;
  	unsigned ctype;
  	unsigned type;
  	unsigned n;
  
  	shared = smem_find(ID_CH_ALLOC_TBL, sizeof(*shared) * 64);
  	if (!shared) {
  		pr_err("cannot find allocation table
  ");
  		return;
  	}
  	for (n = 0; n < 64; n++) {
  		if (smd_ch_allocated[n])
  			continue;
  		if (!shared[n].ref_count)
  			continue;
  		if (!shared[n].name[0])
  			continue;
  		ctype = shared[n].ctype;
  		type = ctype & SMD_TYPE_MASK;
  
  		/* DAL channels are stream but neither the modem,
  		 * nor the DSP correctly indicate this.  Fixup manually.
  		 */
  		if (!memcmp(shared[n].name, "DAL", 3))
  			ctype = (ctype & (~SMD_KIND_MASK)) | SMD_KIND_STREAM;
  
  		type = shared[n].ctype & SMD_TYPE_MASK;
  		if ((type == SMD_TYPE_APPS_MODEM) ||
  		    (type == SMD_TYPE_APPS_DSP))
  			if (!smd_alloc_channel(shared[n].name, shared[n].cid, ctype))
  				smd_ch_allocated[n] = 1;
  	}
  }
  
  static void do_nothing_notify(void *priv, unsigned flags)
  {
  }
  
  struct smd_channel *smd_get_channel(const char *name)
  {
  	struct smd_channel *ch;
  
  	mutex_lock(&smd_creation_mutex);
  	list_for_each_entry(ch, &smd_ch_closed_list, ch_list) {
  		if (!strcmp(name, ch->name)) {
  			list_del(&ch->ch_list);
  			mutex_unlock(&smd_creation_mutex);
  			return ch;
  		}
  	}
  	mutex_unlock(&smd_creation_mutex);
  
  	return NULL;
  }
  
  int smd_open(const char *name, smd_channel_t **_ch,
  	     void *priv, void (*notify)(void *, unsigned))
  {
  	struct smd_channel *ch;
  	unsigned long flags;
  
  	if (smd_initialized == 0) {
  		pr_info("smd_open() before smd_init()
  ");
  		return -ENODEV;
  	}
  
  	ch = smd_get_channel(name);
  	if (!ch)
  		return -ENODEV;
  
  	if (notify == 0)
  		notify = do_nothing_notify;
  
  	ch->notify = notify;
  	ch->current_packet = 0;
  	ch->last_state = SMD_SS_CLOSED;
  	ch->priv = priv;
  
  	*_ch = ch;
  
  	spin_lock_irqsave(&smd_lock, flags);
  
  	if ((ch->type & SMD_TYPE_MASK) == SMD_TYPE_APPS_MODEM)
  		list_add(&ch->ch_list, &smd_ch_list_modem);
  	else
  		list_add(&ch->ch_list, &smd_ch_list_dsp);
  
  	/* If the remote side is CLOSING, we need to get it to
  	 * move to OPENING (which we'll do by moving from CLOSED to
  	 * OPENING) and then get it to move from OPENING to
  	 * OPENED (by doing the same state change ourselves).
  	 *
  	 * Otherwise, it should be OPENING and we can move directly
  	 * to OPENED so that it will follow.
  	 */
  	if (ch->recv->state == SMD_SS_CLOSING) {
  		ch->send->head = 0;
  		ch_set_state(ch, SMD_SS_OPENING);
  	} else {
  		ch_set_state(ch, SMD_SS_OPENED);
  	}
  	spin_unlock_irqrestore(&smd_lock, flags);
  	smd_kick(ch);
  
  	return 0;
  }
  
  int smd_close(smd_channel_t *ch)
  {
  	unsigned long flags;
  
  	if (ch == 0)
  		return -1;
  
  	spin_lock_irqsave(&smd_lock, flags);
  	ch->notify = do_nothing_notify;
  	list_del(&ch->ch_list);
  	ch_set_state(ch, SMD_SS_CLOSED);
  	spin_unlock_irqrestore(&smd_lock, flags);
  
  	mutex_lock(&smd_creation_mutex);
  	list_add(&ch->ch_list, &smd_ch_closed_list);
  	mutex_unlock(&smd_creation_mutex);
  
  	return 0;
  }
  
  int smd_read(smd_channel_t *ch, void *data, int len)
  {
  	return ch->read(ch, data, len);
  }
  
  int smd_write(smd_channel_t *ch, const void *data, int len)
  {
  	return ch->write(ch, data, len);
  }
  
  int smd_write_atomic(smd_channel_t *ch, const void *data, int len)
  {
  	unsigned long flags;
  	int res;
  	spin_lock_irqsave(&smd_lock, flags);
  	res = ch->write(ch, data, len);
  	spin_unlock_irqrestore(&smd_lock, flags);
  	return res;
  }
  
  int smd_read_avail(smd_channel_t *ch)
  {
  	return ch->read_avail(ch);
  }
  
  int smd_write_avail(smd_channel_t *ch)
  {
  	return ch->write_avail(ch);
  }
  
  int smd_wait_until_readable(smd_channel_t *ch, int bytes)
  {
  	return -1;
  }
  
  int smd_wait_until_writable(smd_channel_t *ch, int bytes)
  {
  	return -1;
  }
  
  int smd_cur_packet_size(smd_channel_t *ch)
  {
  	return ch->current_packet;
  }
  
  
  /* ------------------------------------------------------------------------- */
  
  void *smem_alloc(unsigned id, unsigned size)
  {
  	return smem_find(id, size);
  }
  
  void __iomem *smem_item(unsigned id, unsigned *size)
  {
  	struct smem_shared *shared = (void *) MSM_SHARED_RAM_BASE;
  	struct smem_heap_entry *toc = shared->heap_toc;
  
  	if (id >= SMEM_NUM_ITEMS)
  		return NULL;
  
  	if (toc[id].allocated) {
  		*size = toc[id].size;
  		return (MSM_SHARED_RAM_BASE + toc[id].offset);
  	} else {
  		*size = 0;
  	}
  
  	return NULL;
  }
  
  void *smem_find(unsigned id, unsigned size_in)
  {
  	unsigned size;
  	void *ptr;
  
  	ptr = smem_item(id, &size);
  	if (!ptr)
  		return 0;
  
  	size_in = ALIGN(size_in, 8);
  	if (size_in != size) {
  		pr_err("smem_find(%d, %d): wrong size %d
  ",
  		       id, size_in, size);
  		return 0;
  	}
  
  	return ptr;
  }
  
  static irqreturn_t smsm_irq_handler(int irq, void *data)
  {
  	unsigned long flags;
  	unsigned apps, modm;
  
  	spin_lock_irqsave(&smem_lock, flags);
  
  	apps = raw_smsm_get_state(SMSM_STATE_APPS);
  	modm = raw_smsm_get_state(SMSM_STATE_MODEM);
  
  	if (msm_smd_debug_mask & MSM_SMSM_DEBUG)
  		pr_info("<SM %08x %08x>
  ", apps, modm);
  	if (modm & SMSM_RESET)
  		handle_modem_crash();
  
  	do_smd_probe();
  
  	spin_unlock_irqrestore(&smem_lock, flags);
  	return IRQ_HANDLED;
  }
  
  int smsm_change_state(enum smsm_state_item item,
  		      uint32_t clear_mask, uint32_t set_mask)
  {
  	void __iomem *addr = smd_info.state + item * 4;
  	unsigned long flags;
  	unsigned state;
  
  	if (!smd_info.ready)
  		return -EIO;
  
  	spin_lock_irqsave(&smem_lock, flags);
  
  	if (raw_smsm_get_state(SMSM_STATE_MODEM) & SMSM_RESET)
  		handle_modem_crash();
  
  	state = (readl(addr) & ~clear_mask) | set_mask;
  	writel(state, addr);
  
  	if (msm_smd_debug_mask & MSM_SMSM_DEBUG)
  		pr_info("smsm_change_state %d %x
  ", item, state);
  	notify_other_smsm();
  
  	spin_unlock_irqrestore(&smem_lock, flags);
  
  	return 0;
  }
  
  uint32_t smsm_get_state(enum smsm_state_item item)
  {
  	unsigned long flags;
  	uint32_t rv;
  
  	spin_lock_irqsave(&smem_lock, flags);
  
  	rv = readl(smd_info.state + item * 4);
  
  	if (item == SMSM_STATE_MODEM && (rv & SMSM_RESET))
  		handle_modem_crash();
  
  	spin_unlock_irqrestore(&smem_lock, flags);
  
  	return rv;
  }
  
  #ifdef CONFIG_ARCH_MSM_SCORPION
  
  int smsm_set_sleep_duration(uint32_t delay)
  {
  	struct msm_dem_slave_data *ptr;
  
  	ptr = smem_find(SMEM_APPS_DEM_SLAVE_DATA, sizeof(*ptr));
  	if (ptr == NULL) {
  		pr_err("smsm_set_sleep_duration <SM NO APPS_DEM_SLAVE_DATA>
  ");
  		return -EIO;
  	}
  	if (msm_smd_debug_mask & MSM_SMSM_DEBUG)
  		pr_info("smsm_set_sleep_duration %d -> %d
  ",
  		       ptr->sleep_time, delay);
  	ptr->sleep_time = delay;
  	return 0;
  }
  
  #else
  
  int smsm_set_sleep_duration(uint32_t delay)
  {
  	uint32_t *ptr;
  
  	ptr = smem_find(SMEM_SMSM_SLEEP_DELAY, sizeof(*ptr));
  	if (ptr == NULL) {
  		pr_err("smsm_set_sleep_duration <SM NO SLEEP_DELAY>
  ");
  		return -EIO;
  	}
  	if (msm_smd_debug_mask & MSM_SMSM_DEBUG)
  		pr_info("smsm_set_sleep_duration %d -> %d
  ",
  		       *ptr, delay);
  	*ptr = delay;
  	return 0;
  }
  
  #endif
  
  int smd_core_init(void)
  {
  	int r;
  
  	/* wait for essential items to be initialized */
  	for (;;) {
  		unsigned size;
  		void __iomem *state;
  		state = smem_item(SMEM_SMSM_SHARED_STATE, &size);
  		if (size == SMSM_V1_SIZE || size == SMSM_V2_SIZE) {
  			smd_info.state = state;
  			break;
  		}
  	}
  
  	smd_info.ready = 1;
  
  	r = request_irq(INT_A9_M2A_0, smd_modem_irq_handler,
  			IRQF_TRIGGER_RISING, "smd_dev", 0);
  	if (r < 0)
  		return r;
  	r = enable_irq_wake(INT_A9_M2A_0);
  	if (r < 0)
  		pr_err("smd_core_init: enable_irq_wake failed for A9_M2A_0
  ");
  
  	r = request_irq(INT_A9_M2A_5, smsm_irq_handler,
  			IRQF_TRIGGER_RISING, "smsm_dev", 0);
  	if (r < 0) {
  		free_irq(INT_A9_M2A_0, 0);
  		return r;
  	}
  	r = enable_irq_wake(INT_A9_M2A_5);
  	if (r < 0)
  		pr_err("smd_core_init: enable_irq_wake failed for A9_M2A_5
  ");
  
  #if defined(CONFIG_QDSP6)
  	r = request_irq(INT_ADSP_A11, smd_dsp_irq_handler,
  			IRQF_TRIGGER_RISING, "smd_dsp", 0);
  	if (r < 0) {
  		free_irq(INT_A9_M2A_0, 0);
  		free_irq(INT_A9_M2A_5, 0);
  		return r;
  	}
  #endif
  
  	/* check for any SMD channels that may already exist */
  	do_smd_probe();
  
  	/* indicate that we're up and running */
  	smsm_change_state(SMSM_STATE_APPS,
  			  ~0, SMSM_INIT | SMSM_SMDINIT | SMSM_RPCINIT | SMSM_RUN);
  #ifdef CONFIG_ARCH_MSM_SCORPION
  	smsm_change_state(SMSM_STATE_APPS_DEM, ~0, 0);
  #endif
  
  	return 0;
  }
  
  static int msm_smd_probe(struct platform_device *pdev)
  {
  	/*
  	 * If we haven't waited for the ARM9 to boot up till now,
  	 * then we need to wait here. Otherwise this should just
  	 * return immediately.
  	 */
  	proc_comm_boot_wait();
  
  	INIT_WORK(&probe_work, smd_channel_probe_worker);
  
  	if (smd_core_init()) {
  		pr_err("smd_core_init() failed
  ");
  		return -1;
  	}
  
  	do_smd_probe();
  
  	msm_check_for_modem_crash = check_for_modem_crash;
  
  	msm_init_last_radio_log(THIS_MODULE);
  
  	smd_initialized = 1;
  
  	return 0;
  }
  
  static struct platform_driver msm_smd_driver = {
  	.probe = msm_smd_probe,
  	.driver = {
  		.name = MODULE_NAME,
  		.owner = THIS_MODULE,
  	},
  };
  
  static int __init msm_smd_init(void)
  {
  	return platform_driver_register(&msm_smd_driver);
  }
  
  module_init(msm_smd_init);
  
  MODULE_DESCRIPTION("MSM Shared Memory Core");
  MODULE_AUTHOR("Brian Swetland <swetland@google.com>");
  MODULE_LICENSE("GPL");