[ARM] msm: shared memory interface for baseband processor ipc

This code provides the low level interface to the "shared memory
state machine" (smsm), and the virtual serial channels (smd), used
to communicate with the baseband processor.  Higher level transports
(rpc, ethernet, AT command channel, etc) ride on top of this.

Signed-off-by: Brian Swetland <swetland@google.com>

1 files changed, 1330 insertions, 0 deletions

diff --git a/arch/arm/mach-msm/smd.c b/arch/arm/mach-msm/smd.c
new file mode 100644
index 000000000000..64d12323995e
--- /dev/null
+++ b/arch/arm/mach-msm/smd.c
@@ -0,0 +1,1330 @@
+/* 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.
+ *
+ */
+
+#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 <linux/io.h>
+
+#include <mach/msm_smd.h>
+#include <mach/msm_iomap.h>
+#include <mach/system.h>
+
+#include "smd_private.h"
+#include "proc_comm.h"
+
+void (*msm_hw_reset_hook)(void);
+
+#define MODULE_NAME "msm_smd"
+
+enum {
+	MSM_SMD_DEBUG = 1U << 0,
+	MSM_SMSM_DEBUG = 1U << 0,
+};
+
+static int msm_smd_debug_mask;
+
+module_param_named(debug_mask, msm_smd_debug_mask,
+		   int, S_IRUGO | S_IWUSR | S_IWGRP);
+
+void *smem_find(unsigned id, unsigned size);
+static void smd_diag(void);
+
+static unsigned last_heap_free = 0xffffffff;
+
+#define MSM_A2M_INT(n) (MSM_CSR_BASE + 0x400 + (n) * 4)
+
+static inline void notify_other_smsm(void)
+{
+	writel(1, MSM_A2M_INT(5));
+}
+
+static inline void notify_other_smd(void)
+{
+	writel(1, MSM_A2M_INT(0));
+}
+
+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_info("smem: DIAG '%s'\n", 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\n");
+	smd_diag();
+
+	/* hard reboot if possible */
+	if (msm_hw_reset_hook)
+		msm_hw_reset_hook();
+
+	/* in this case the modem or watchdog should reboot us */
+	for (;;)
+		;
+}
+
+extern int (*msm_check_for_modem_crash)(void);
+
+static int check_for_modem_crash(void)
+{
+	struct smsm_shared *smsm;
+
+	smsm = smem_find(ID_SHARED_STATE, 2 * sizeof(struct smsm_shared));
+
+	/* if the modem's not ready yet, we have to hope for the best */
+	if (!smsm)
+		return 0;
+
+	if (smsm[1].state & SMSM_RESET) {
+		handle_modem_crash();
+		return -1;
+	} else {
+		return 0;
+	}
+}
+
+#define SMD_SS_CLOSED            0x00000000
+#define SMD_SS_OPENING           0x00000001
+#define SMD_SS_OPENED            0x00000002
+#define SMD_SS_FLUSHING          0x00000003
+#define SMD_SS_CLOSING           0x00000004
+#define SMD_SS_RESET             0x00000005
+#define SMD_SS_RESET_OPENING     0x00000006
+
+#define SMD_BUF_SIZE 8192
+#define SMD_CHANNELS 64
+
+#define SMD_HEADER_SIZE 20
+
+
+/* the spinlock is used to synchronize between the
+** irq handler and code that mutates the channel
+** list or fiddles with channel state
+*/
+static DEFINE_SPINLOCK(smd_lock);
+static 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;
+
+struct smd_alloc_elm {
+	char name[20];
+	uint32_t cid;
+	uint32_t ctype;
+	uint32_t ref_count;
+};
+
+struct smd_half_channel {
+	unsigned state;
+	unsigned char fDSR;
+	unsigned char fCTS;
+	unsigned char fCD;
+	unsigned char fRI;
+	unsigned char fHEAD;
+	unsigned char fTAIL;
+	unsigned char fSTATE;
+	unsigned char fUNUSED;
+	unsigned tail;
+	unsigned head;
+	unsigned char data[SMD_BUF_SIZE];
+};
+
+struct smd_shared {
+	struct smd_half_channel ch0;
+	struct smd_half_channel ch1;
+};
+
+struct smd_channel {
+	volatile struct smd_half_channel *send;
+	volatile struct smd_half_channel *recv;
+	struct list_head ch_list;
+
+	unsigned current_packet;
+	unsigned n;
+	void *priv;
+	void (*notify)(void *priv, unsigned flags);
+
+	int (*read)(smd_channel_t *ch, void *data, int len);
+	int (*write)(smd_channel_t *ch, const void *data, int len);
+	int (*read_avail)(smd_channel_t *ch);
+	int (*write_avail)(smd_channel_t *ch);
+
+	void (*update_state)(smd_channel_t *ch);
+	unsigned last_state;
+
+	char name[32];
+	struct platform_device pdev;
+};
+
+static LIST_HEAD(smd_ch_closed_list);
+static LIST_HEAD(smd_ch_list);
+
+static unsigned char smd_ch_allocated[64];
+static struct work_struct probe_work;
+
+static void smd_alloc_channel(const char *name, uint32_t cid, uint32_t type);
+
+static void smd_channel_probe_worker(struct work_struct *work)
+{
+	struct smd_alloc_elm *shared;
+	unsigned n;
+
+	shared = smem_find(ID_CH_ALLOC_TBL, sizeof(*shared) * 64);
+
+	for (n = 0; n < 64; n++) {
+		if (smd_ch_allocated[n])
+			continue;
+		if (!shared[n].ref_count)
+			continue;
+		if (!shared[n].name[0])
+			continue;
+		smd_alloc_channel(shared[n].name,
+				  shared[n].cid,
+				  shared[n].ctype);
+		smd_ch_allocated[n] = 1;
+	}
+}
+
+static char *chstate(unsigned n)
+{
+	switch (n) {
+	case SMD_SS_CLOSED:
+		return "CLOSED";
+	case SMD_SS_OPENING:
+		return "OPENING";
+	case SMD_SS_OPENED:
+		return "OPENED";
+	case SMD_SS_FLUSHING:
+		return "FLUSHING";
+	case SMD_SS_CLOSING:
+		return "CLOSING";
+	case SMD_SS_RESET:
+		return "RESET";
+	case SMD_SS_RESET_OPENING:
+		return "ROPENING";
+	default:
+		return "UNKNOWN";
+	}
+}
+
+/* how many bytes are available for reading */
+static int smd_stream_read_avail(struct smd_channel *ch)
+{
+	return (ch->recv->head - ch->recv->tail) & (SMD_BUF_SIZE - 1);
+}
+
+/* how many bytes we are free to write */
+static int smd_stream_write_avail(struct smd_channel *ch)
+{
+	return (SMD_BUF_SIZE - 1) -
+		((ch->send->head - ch->send->tail) & (SMD_BUF_SIZE - 1));
+}
+
+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 SMD_BUF_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) & (SMD_BUF_SIZE - 1);
+	ch->recv->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 SMD_BUF_SIZE - head - 1;
+		else
+			return SMD_BUF_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) & (SMD_BUF_SIZE - 1);
+	ch->send->fHEAD = 1;
+}
+
+static void hc_set_state(volatile struct smd_half_channel *hc, unsigned n)
+{
+	if (n == SMD_SS_OPENED) {
+		hc->fDSR = 1;
+		hc->fCTS = 1;
+		hc->fCD = 1;
+	} else {
+		hc->fDSR = 0;
+		hc->fCTS = 0;
+		hc->fCD = 0;
+	}
+	hc->state = n;
+	hc->fSTATE = 1;
+	notify_other_smd();
+}
+
+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_info("SMD: ch %d %s -> %s\n", ch->n,
+		chstate(last), chstate(next));
+
+	switch (next) {
+	case SMD_SS_OPENING:
+		ch->recv->tail = 0;
+	case SMD_SS_OPENED:
+		if (ch->send->state != SMD_SS_OPENED)
+			hc_set_state(ch->send, 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 irqreturn_t smd_irq_handler(int irq, void *data)
+{
+	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, &smd_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_other_smd();
+	spin_unlock_irqrestore(&smd_lock, flags);
+	do_smd_probe();
+	return IRQ_HANDLED;
+}
+
+static void smd_fake_irq_handler(unsigned long arg)
+{
+	smd_irq_handler(0, NULL);
+}
+
+static DECLARE_TASKLET(smd_fake_irq_tasklet, smd_fake_irq_handler, 0);
+
+void smd_sleep_exit(void)
+{
+	unsigned long flags;
+	struct smd_channel *ch;
+	unsigned tmp;
+	int need_int = 0;
+
+	spin_lock_irqsave(&smd_lock, flags);
+	list_for_each_entry(ch, &smd_ch_list, ch_list) {
+		if (ch_is_open(ch)) {
+			if (ch->recv->fHEAD) {
+				if (msm_smd_debug_mask & MSM_SMD_DEBUG)
+					pr_info("smd_sleep_exit ch %d fHEAD "
+						"%x %x %x\n",
+						ch->n, ch->recv->fHEAD,
+						ch->recv->head, ch->recv->tail);
+				need_int = 1;
+				break;
+			}
+			if (ch->recv->fTAIL) {
+				if (msm_smd_debug_mask & MSM_SMD_DEBUG)
+					pr_info("smd_sleep_exit ch %d fTAIL "
+						"%x %x %x\n",
+						ch->n, ch->recv->fTAIL,
+						ch->send->head, ch->send->tail);
+				need_int = 1;
+				break;
+			}
+			if (ch->recv->fSTATE) {
+				if (msm_smd_debug_mask & MSM_SMD_DEBUG)
+					pr_info("smd_sleep_exit ch %d fSTATE %x"
+						"\n", ch->n, ch->recv->fSTATE);
+				need_int = 1;
+				break;
+			}
+			tmp = ch->recv->state;
+			if (tmp != ch->last_state) {
+				if (msm_smd_debug_mask & MSM_SMD_DEBUG)
+					pr_info("smd_sleep_exit ch %d "
+						"state %x != %x\n",
+						ch->n, tmp, ch->last_state);
+				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\n");
+		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);
+	notify_other_smd();
+	spin_unlock_irqrestore(&smd_lock, flags);
+}
+
+static int smd_is_packet(int chn)
+{
+	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;
+	}
+
+	notify_other_smd();
+
+	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)
+		notify_other_smd();
+
+	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)
+		notify_other_smd();
+
+	spin_lock_irqsave(&smd_lock, flags);
+	ch->current_packet -= r;
+	update_packet_state(ch);
+	spin_unlock_irqrestore(&smd_lock, flags);
+
+	return r;
+}
+
+static void smd_alloc_channel(const char *name, uint32_t cid, uint32_t type)
+{
+	struct smd_channel *ch;
+	struct smd_shared *shared;
+
+	shared = smem_alloc(ID_SMD_CHANNELS + cid, sizeof(*shared));
+	if (!shared) {
+		pr_err("smd_alloc_channel() cid %d does not exist\n", cid);
+		return;
+	}
+
+	ch = kzalloc(sizeof(struct smd_channel), GFP_KERNEL);
+	if (ch == 0) {
+		pr_err("smd_alloc_channel() out of memory\n");
+		return;
+	}
+
+	ch->send = &shared->ch0;
+	ch->recv = &shared->ch1;
+	ch->n = cid;
+
+	if (smd_is_packet(cid)) {
+		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;
+	}
+
+	memcpy(ch->name, "SMD_", 4);
+	memcpy(ch->name + 4, name, 20);
+	ch->name[23] = 0;
+	ch->pdev.name = ch->name;
+	ch->pdev.id = -1;
+
+	pr_info("smd_alloc_channel() '%s' cid=%d, shared=%p\n",
+		ch->name, ch->n, shared);
+
+	mutex_lock(&smd_creation_mutex);
+	list_add(&ch->ch_list, &smd_ch_closed_list);
+	mutex_unlock(&smd_creation_mutex);
+
+	platform_device_register(&ch->pdev);
+}
+
+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()\n");
+		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);
+	list_add(&ch->ch_list, &smd_ch_list);
+
+	/* 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;
+		hc_set_state(ch->send, SMD_SS_OPENING);
+	} else {
+		hc_set_state(ch->send, SMD_SS_OPENED);
+	}
+	spin_unlock_irqrestore(&smd_lock, flags);
+	smd_kick(ch);
+
+	return 0;
+}
+
+int smd_close(smd_channel_t *ch)
+{
+	unsigned long flags;
+
+	pr_info("smd_close(%p)\n", ch);
+
+	if (ch == 0)
+		return -1;
+
+	spin_lock_irqsave(&smd_lock, flags);
+	ch->notify = do_nothing_notify;
+	list_del(&ch->ch_list);
+	hc_set_state(ch->send, 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_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);
+}
+
+static void *_smem_find(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 0;
+
+	if (toc[id].allocated) {
+		*size = toc[id].size;
+		return (void *) (MSM_SHARED_RAM_BASE + toc[id].offset);
+	}
+
+	return 0;
+}
+
+void *smem_find(unsigned id, unsigned size_in)
+{
+	unsigned size;
+	void *ptr;
+
+	ptr = _smem_find(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\n",
+		       id, size_in, size);
+		return 0;
+	}
+
+	return ptr;
+}
+
+static irqreturn_t smsm_irq_handler(int irq, void *data)
+{
+	unsigned long flags;
+	struct smsm_shared *smsm;
+
+	spin_lock_irqsave(&smem_lock, flags);
+	smsm = smem_alloc(ID_SHARED_STATE,
+			  2 * sizeof(struct smsm_shared));
+
+	if (smsm == 0) {
+		pr_info("<SM NO STATE>\n");
+	} else {
+		unsigned apps = smsm[0].state;
+		unsigned modm = smsm[1].state;
+
+		if (msm_smd_debug_mask & MSM_SMSM_DEBUG)
+			pr_info("<SM %08x %08x>\n", apps, modm);
+		if (modm & SMSM_RESET) {
+			handle_modem_crash();
+		} else {
+			apps |= SMSM_INIT;
+			if (modm & SMSM_SMDINIT)
+				apps |= SMSM_SMDINIT;
+			if (modm & SMSM_RPCINIT)
+				apps |= SMSM_RPCINIT;
+		}
+
+		if (smsm[0].state != apps) {
+			if (msm_smd_debug_mask & MSM_SMSM_DEBUG)
+				pr_info("<SM %08x NOTIFY>\n", apps);
+			smsm[0].state = apps;
+			do_smd_probe();
+			notify_other_smsm();
+		}
+	}
+	spin_unlock_irqrestore(&smem_lock, flags);
+	return IRQ_HANDLED;
+}
+
+int smsm_change_state(uint32_t clear_mask, uint32_t set_mask)
+{
+	unsigned long flags;
+	struct smsm_shared *smsm;
+
+	spin_lock_irqsave(&smem_lock, flags);
+
+	smsm = smem_alloc(ID_SHARED_STATE,
+			  2 * sizeof(struct smsm_shared));
+
+	if (smsm) {
+		if (smsm[1].state & SMSM_RESET)
+			handle_modem_crash();
+		smsm[0].state = (smsm[0].state & ~clear_mask) | set_mask;
+		if (msm_smd_debug_mask & MSM_SMSM_DEBUG)
+			pr_info("smsm_change_state %x\n",
+			       smsm[0].state);
+		notify_other_smsm();
+	}
+
+	spin_unlock_irqrestore(&smem_lock, flags);
+
+	if (smsm == NULL) {
+		pr_err("smsm_change_state <SM NO STATE>\n");
+		return -EIO;
+	}
+	return 0;
+}
+
+uint32_t smsm_get_state(void)
+{
+	unsigned long flags;
+	struct smsm_shared *smsm;
+	uint32_t rv;
+
+	spin_lock_irqsave(&smem_lock, flags);
+
+	smsm = smem_alloc(ID_SHARED_STATE,
+			  2 * sizeof(struct smsm_shared));
+
+	if (smsm)
+		rv = smsm[1].state;
+	else
+		rv = 0;
+
+	if (rv & SMSM_RESET)
+		handle_modem_crash();
+
+	spin_unlock_irqrestore(&smem_lock, flags);
+
+	if (smsm == NULL)
+		pr_err("smsm_get_state <SM NO STATE>\n");
+	return rv;
+}
+
+int smsm_set_sleep_duration(uint32_t delay)
+{
+	uint32_t *ptr;
+
+	ptr = smem_alloc(SMEM_SMSM_SLEEP_DELAY, sizeof(*ptr));
+	if (ptr == NULL) {
+		pr_err("smsm_set_sleep_duration <SM NO SLEEP_DELAY>\n");
+		return -EIO;
+	}
+	if (msm_smd_debug_mask & MSM_SMSM_DEBUG)
+		pr_info("smsm_set_sleep_duration %d -> %d\n",
+		       *ptr, delay);
+	*ptr = delay;
+	return 0;
+}
+
+int smsm_set_interrupt_info(struct smsm_interrupt_info *info)
+{
+	struct smsm_interrupt_info *ptr;
+
+	ptr = smem_alloc(SMEM_SMSM_INT_INFO, sizeof(*ptr));
+	if (ptr == NULL) {
+		pr_err("smsm_set_sleep_duration <SM NO INT_INFO>\n");
+		return -EIO;
+	}
+	if (msm_smd_debug_mask & MSM_SMSM_DEBUG)
+		pr_info("smsm_set_interrupt_info %x %x -> %x %x\n",
+		       ptr->aArm_en_mask, ptr->aArm_interrupts_pending,
+		       info->aArm_en_mask, info->aArm_interrupts_pending);
+	*ptr = *info;
+	return 0;
+}
+
+#define MAX_NUM_SLEEP_CLIENTS		64
+#define MAX_SLEEP_NAME_LEN		8
+
+#define NUM_GPIO_INT_REGISTERS		6
+#define GPIO_SMEM_NUM_GROUPS		2
+#define GPIO_SMEM_MAX_PC_INTERRUPTS	8
+
+struct tramp_gpio_save {
+	unsigned int enable;
+	unsigned int detect;
+	unsigned int polarity;
+};
+
+struct tramp_gpio_smem {
+	uint16_t num_fired[GPIO_SMEM_NUM_GROUPS];
+	uint16_t fired[GPIO_SMEM_NUM_GROUPS][GPIO_SMEM_MAX_PC_INTERRUPTS];
+	uint32_t enabled[NUM_GPIO_INT_REGISTERS];
+	uint32_t detection[NUM_GPIO_INT_REGISTERS];
+	uint32_t polarity[NUM_GPIO_INT_REGISTERS];
+};
+
+
+void smsm_print_sleep_info(void)
+{
+	unsigned long flags;
+	uint32_t *ptr;
+	struct tramp_gpio_smem *gpio;
+	struct smsm_interrupt_info *int_info;
+
+
+	spin_lock_irqsave(&smem_lock, flags);
+
+	ptr = smem_alloc(SMEM_SMSM_SLEEP_DELAY, sizeof(*ptr));
+	if (ptr)
+		pr_info("SMEM_SMSM_SLEEP_DELAY: %x\n", *ptr);
+
+	ptr = smem_alloc(SMEM_SMSM_LIMIT_SLEEP, sizeof(*ptr));
+	if (ptr)
+		pr_info("SMEM_SMSM_LIMIT_SLEEP: %x\n", *ptr);
+
+	ptr = smem_alloc(SMEM_SLEEP_POWER_COLLAPSE_DISABLED, sizeof(*ptr));
+	if (ptr)
+		pr_info("SMEM_SLEEP_POWER_COLLAPSE_DISABLED: %x\n", *ptr);
+
+	int_info = smem_alloc(SMEM_SMSM_INT_INFO, sizeof(*int_info));
+	if (int_info)
+		pr_info("SMEM_SMSM_INT_INFO %x %x %x\n",
+			int_info->aArm_en_mask,
+			int_info->aArm_interrupts_pending,
+			int_info->aArm_wakeup_reason);
+
+	gpio = smem_alloc(SMEM_GPIO_INT, sizeof(*gpio));
+	if (gpio) {
+		int i;
+		for (i = 0; i < NUM_GPIO_INT_REGISTERS; i++)
+			pr_info("SMEM_GPIO_INT: %d: e %x d %x p %x\n",
+				i, gpio->enabled[i], gpio->detection[i],
+				gpio->polarity[i]);
+
+		for (i = 0; i < GPIO_SMEM_NUM_GROUPS; i++)
+			pr_info("SMEM_GPIO_INT: %d: f %d: %d %d...\n",
+				i, gpio->num_fired[i], gpio->fired[i][0],
+				gpio->fired[i][1]);
+	}
+
+	spin_unlock_irqrestore(&smem_lock, flags);
+}
+
+int smd_core_init(void)
+{
+	int r;
+	pr_info("smd_core_init()\n");
+
+	r = request_irq(INT_A9_M2A_0, smd_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\n");
+
+	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\n");
+
+	/* we may have missed a signal while booting -- fake
+	 * an interrupt to make sure we process any existing
+	 * state
+	 */
+	smsm_irq_handler(0, 0);
+
+	pr_info("smd_core_init() done\n");
+
+	return 0;
+}
+
+#if defined(CONFIG_DEBUG_FS)
+
+static int dump_ch(char *buf, int max, int n,
+		  struct smd_half_channel *s,
+		  struct smd_half_channel *r)
+{
+	return scnprintf(
+		buf, max,
+		"ch%02d:"
+		" %8s(%04d/%04d) %c%c%c%c%c%c%c <->"
+		" %8s(%04d/%04d) %c%c%c%c%c%c%c\n", n,
+		chstate(s->state), s->tail, s->head,
+		s->fDSR ? 'D' : 'd',
+		s->fCTS ? 'C' : 'c',
+		s->fCD ? 'C' : 'c',
+		s->fRI ? 'I' : 'i',
+		s->fHEAD ? 'W' : 'w',
+		s->fTAIL ? 'R' : 'r',
+		s->fSTATE ? 'S' : 's',
+		chstate(r->state), r->tail, r->head,
+		r->fDSR ? 'D' : 'd',
+		r->fCTS ? 'R' : 'r',
+		r->fCD ? 'C' : 'c',
+		r->fRI ? 'I' : 'i',
+		r->fHEAD ? 'W' : 'w',
+		r->fTAIL ? 'R' : 'r',
+		r->fSTATE ? 'S' : 's'
+		);
+}
+
+static int debug_read_stat(char *buf, int max)
+{
+	struct smsm_shared *smsm;
+	char *msg;
+	int i = 0;
+
+	smsm = smem_find(ID_SHARED_STATE,
+			 2 * sizeof(struct smsm_shared));
+
+	msg = smem_find(ID_DIAG_ERR_MSG, SZ_DIAG_ERR_MSG);
+
+	if (smsm) {
+		if (smsm[1].state & SMSM_RESET)
+			i += scnprintf(buf + i, max - i,
+				       "smsm: ARM9 HAS CRASHED\n");
+		i += scnprintf(buf + i, max - i, "smsm: a9: %08x a11: %08x\n",
+			       smsm[0].state, smsm[1].state);
+	} else {
+		i += scnprintf(buf + i, max - i, "smsm: cannot find\n");
+	}
+	if (msg) {
+		msg[SZ_DIAG_ERR_MSG - 1] = 0;
+		i += scnprintf(buf + i, max - i, "diag: '%s'\n", msg);
+	}
+	return i;
+}
+
+static int debug_read_mem(char *buf, int max)
+{
+	unsigned n;
+	struct smem_shared *shared = (void *) MSM_SHARED_RAM_BASE;
+	struct smem_heap_entry *toc = shared->heap_toc;
+	int i = 0;
+
+	i += scnprintf(buf + i, max - i,
+		       "heap: init=%d free=%d remain=%d\n",
+		       shared->heap_info.initialized,
+		       shared->heap_info.free_offset,
+		       shared->heap_info.heap_remaining);
+
+	for (n = 0; n < SMEM_NUM_ITEMS; n++) {
+		if (toc[n].allocated == 0)
+			continue;
+		i += scnprintf(buf + i, max - i,
+			       "%04d: offsed %08x size %08x\n",
+			       n, toc[n].offset, toc[n].size);
+	}
+	return i;
+}
+
+static int debug_read_ch(char *buf, int max)
+{
+	struct smd_shared *shared;
+	int n, i = 0;
+
+	for (n = 0; n < SMD_CHANNELS; n++) {
+		shared = smem_find(ID_SMD_CHANNELS + n,
+				   sizeof(struct smd_shared));
+		if (shared == 0)
+			continue;
+		i += dump_ch(buf + i, max - i, n, &shared->ch0, &shared->ch1);
+	}
+
+	return i;
+}
+
+static int debug_read_version(char *buf, int max)
+{
+	struct smem_shared *shared = (void *) MSM_SHARED_RAM_BASE;
+	unsigned version = shared->version[VERSION_MODEM];
+	return sprintf(buf, "%d.%d\n", version >> 16, version & 0xffff);
+}
+
+static int debug_read_build_id(char *buf, int max)
+{
+	unsigned size;
+	void *data;
+
+	data = _smem_find(SMEM_HW_SW_BUILD_ID, &size);
+	if (!data)
+		return 0;
+
+	if (size >= max)
+		size = max;
+	memcpy(buf, data, size);
+
+	return size;
+}
+
+static int debug_read_alloc_tbl(char *buf, int max)
+{
+	struct smd_alloc_elm *shared;
+	int n, i = 0;
+
+	shared = smem_find(ID_CH_ALLOC_TBL, sizeof(*shared) * 64);
+
+	for (n = 0; n < 64; n++) {
+		if (shared[n].ref_count == 0)
+			continue;
+		i += scnprintf(buf + i, max - i,
+			       "%03d: %20s cid=%02d ctype=%d ref_count=%d\n",
+			       n, shared[n].name, shared[n].cid,
+			       shared[n].ctype, shared[n].ref_count);
+	}
+
+	return i;
+}
+
+static int debug_boom(char *buf, int max)
+{
+	unsigned ms = 5000;
+	msm_proc_comm(PCOM_RESET_MODEM, &ms, 0);
+	return 0;
+}
+
+#define DEBUG_BUFMAX 4096
+static char debug_buffer[DEBUG_BUFMAX];
+
+static ssize_t debug_read(struct file *file, char __user *buf,
+			  size_t count, loff_t *ppos)
+{
+	int (*fill)(char *buf, int max) = file->private_data;
+	int bsize = fill(debug_buffer, DEBUG_BUFMAX);
+	return simple_read_from_buffer(buf, count, ppos, debug_buffer, bsize);
+}
+
+static int debug_open(struct inode *inode, struct file *file)
+{
+	file->private_data = inode->i_private;
+	return 0;
+}
+
+static const struct file_operations debug_ops = {
+	.read = debug_read,
+	.open = debug_open,
+};
+
+static void debug_create(const char *name, mode_t mode,
+			 struct dentry *dent,
+			 int (*fill)(char *buf, int max))
+{
+	debugfs_create_file(name, mode, dent, fill, &debug_ops);
+}
+
+static void smd_debugfs_init(void)
+{
+	struct dentry *dent;
+
+	dent = debugfs_create_dir("smd", 0);
+	if (IS_ERR(dent))
+		return;
+
+	debug_create("ch", 0444, dent, debug_read_ch);
+	debug_create("stat", 0444, dent, debug_read_stat);
+	debug_create("mem", 0444, dent, debug_read_mem);
+	debug_create("version", 0444, dent, debug_read_version);
+	debug_create("tbl", 0444, dent, debug_read_alloc_tbl);
+	debug_create("build", 0444, dent, debug_read_build_id);
+	debug_create("boom", 0444, dent, debug_boom);
+}
+#else
+static void smd_debugfs_init(void) {}
+#endif
+
+static int __init msm_smd_probe(struct platform_device *pdev)
+{
+	pr_info("smd_init()\n");
+
+	INIT_WORK(&probe_work, smd_channel_probe_worker);
+
+	if (smd_core_init()) {
+		pr_err("smd_core_init() failed\n");
+		return -1;
+	}
+
+	do_smd_probe();
+
+	msm_check_for_modem_crash = check_for_modem_crash;
+
+	smd_debugfs_init();
+	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");