path: root/arch/arm/mach-msm/smd.c

/* 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 <mach/system.h>

#include "smd_private.h"
#include "proc_comm.h"

#if defined(CONFIG_ARCH_QSD8X50)
#define CONFIG_QDSP6 1
#endif

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;

struct shared_info {
	int ready;
	unsigned state;
};

static unsigned dummy_state[SMSM_STATE_COUNT];

static struct shared_info smd_info = {
	.state = (unsigned) &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'\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 (;;)
		;
}

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 *