/* arch/arm/mach-msm/qdsp5/audmgr.c
 *
 * interface to "audmgr" service on the baseband cpu
 *
 * Copyright (C) 2008 Google, Inc.
 *
 * 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/module.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/wait.h>

#include <asm/atomic.h>
#include <mach/msm_rpcrouter.h>

#include "audmgr.h"

#define STATE_CLOSED    0
#define STATE_DISABLED  1
#define STATE_ENABLING  2
#define STATE_ENABLED   3
#define STATE_DISABLING 4
#define STATE_ERROR	5

static void rpc_ack(struct msm_rpc_endpoint *ept, uint32_t xid)
{
	uint32_t rep[6];

	rep[0] = cpu_to_be32(xid);
	rep[1] = cpu_to_be32(1);
	rep[2] = cpu_to_be32(RPCMSG_REPLYSTAT_ACCEPTED);
	rep[3] = cpu_to_be32(RPC_ACCEPTSTAT_SUCCESS);
	rep[4] = 0;
	rep[5] = 0;

	msm_rpc_write(ept, rep, sizeof(rep));
}

static void process_audmgr_callback(struct audmgr *am,
				   struct rpc_audmgr_cb_func_ptr *args,
				   int len)
{
	if (len < (sizeof(uint32_t) * 3))
		return;
	if (be32_to_cpu(args->set_to_one) != 1)
		return;

	switch (be32_to_cpu(args->status)) {
	case RPC_AUDMGR_STATUS_READY:
		if (len < sizeof(uint32_t) * 4)
			break;
		am->handle = be32_to_cpu(args->u.handle);
		pr_info("audmgr: rpc READY handle=0x%08x\n", am->handle);
		break;
	case RPC_AUDMGR_STATUS_CODEC_CONFIG: {
		uint32_t volume;
		if (len < sizeof(uint32_t) * 4)
			break;
		volume = be32_to_cpu(args->u.volume);
		pr_info("audmgr: rpc CODEC_CONFIG volume=0x%08x\n", volume);
		am->state = STATE_ENABLED;
		wake_up(&am->wait);
		break;
	}
	case RPC_AUDMGR_STATUS_PENDING:
		pr_err("audmgr: PENDING?\n");
		break;
	case RPC_AUDMGR_STATUS_SUSPEND:
		pr_err("audmgr: SUSPEND?\n");
		break;
	case RPC_AUDMGR_STATUS_FAILURE:
		pr_err("audmgr: FAILURE\n");
		break;
	case RPC_AUDMGR_STATUS_VOLUME_CHANGE:
		pr_err("audmgr: VOLUME_CHANGE?\n");
		break;
	case RPC_AUDMGR_STATUS_DISABLED:
		pr_err("audmgr: DISABLED\n");
		am->state = STATE_DISABLED;
		wake_up(&am->wait);
		break;
	case RPC_AUDMGR_STATUS_ERROR:
		pr_err("audmgr: ERROR?\n");
		am->state = STATE_ERROR;
		wake_up(&am->wait);
		break;
	default:
		break;
	}
}

static void process_rpc_request(uint32_t proc, uint32_t xid,
				void *data, int len, void *private)
{
	struct audmgr *am = private;
	uint32_t *x = data;

	if (0) {
		int n = len / 4;
		pr_info("rpc_call proc %d:", proc);
		while (n--)
			printk(" %08x", be32_to_cpu(*x++));
		printk("\n");
	}

	if (proc == AUDMGR_CB_FUNC_PTR)
		process_audmgr_callback(am, data, len);
	else
		pr_err("audmgr: unknown rpc proc %d\n", proc);
	rpc_ack(am->ept, xid);
}

#define RPC_TYPE_REQUEST 0
#define RPC_TYPE_REPLY 1

#define RPC_VERSION 2

#define RPC_COMMON_HDR_SZ  (sizeof(uint32_t) * 2)
#define RPC_REQUEST_HDR_SZ (sizeof(struct rpc_request_hdr))
#define RPC_REPLY_HDR_SZ   (sizeof(uint32_t) * 3)
#define RPC_REPLY_SZ       (sizeof(uint32_t) * 6)

static int audmgr_rpc_thread(void *data)
{
	struct audmgr *am = data;
	struct rpc_request_hdr *hdr = NULL;
	uint32_t type;
	int len;

	pr_info("audmgr_rpc_thread() start\n");

	while (!kthread_should_stop()) {
		if (hdr) {
			kfree(hdr);
			hdr = NULL;
		}
		len = msm_rpc_read(am->ept, (void **) &hdr, -1, -1);
		if (len < 0) {
			pr_err("audmgr: rpc read failed (%d)\n", len);
			break;
		}
		if (len < RPC_COMMON_HDR_SZ)
			continue;

		type = be32_to_cpu(hdr->type);
		if (type == RPC_TYPE_REPLY) {
			struct rpc_reply_hdr *rep = (void *) hdr;
			uint32_t status;
			if (len < RPC_REPLY_HDR_SZ)
				continue;
			status = be32_to_cpu(rep->reply_stat);
			if (status == RPCMSG_REPLYSTAT_ACCEPTED) {
				status = be32_to_cpu(rep->data.acc_hdr.accept_stat);
				pr_info("audmgr: rpc_reply status %d\n", status);
			} else {
				pr_info("audmgr: rpc_reply denied!\n");
			}
			/* process reply */
			continue;
		}

		if (len < RPC_REQUEST_HDR_SZ)
			continue;

		process_rpc_request(be32_to_cpu(hdr->procedure),
				    be32_to_cpu(hdr->xid),
				    (void *) (hdr + 1),
				    len - sizeof(*hdr),
				    data);
	}
	pr_info("audmgr_rpc_thread() exit\n");
	if (hdr) {
		kfree(hdr);
		hdr = NULL;
	}
	am->task = NULL;
	wake_up(&am->wait);
	return 0;
}

struct audmgr_enable_msg {
	struct rpc_request_hdr hdr;
	struct rpc_audmgr_enable_client_args args;
};

struct audmgr_disable_msg {
	struct rpc_request_hdr hdr;
	uint32_t handle;
};

int audmgr_open(struct audmgr *am)
{
	int rc;

	if (am->state != STATE_CLOSED)
		return 0;

	am->ept = msm_rpc_connect(AUDMGR_PROG,
				AUDMGR_VERS,
				MSM_RPC_UNINTERRUPTIBLE);

	init_waitqueue_head(&am->wait);

	if (IS_ERR(am->ept)) {
		rc = PTR_ERR(am->ept);
		am->ept = NULL;
		pr_err("audmgr: failed to connect to audmgr svc\n");
		return rc;
	}

	am->task = kthread_run(audmgr_rpc_thread, am, "audmgr_rpc");
	if (IS_ERR(am->task)) {
		rc = PTR_ERR(am->task);
		am->task = NULL;
		msm_rpc_close(am->ept);
		am->ept = NULL;
		return rc;
	}

	am->state = STATE_DISABLED;
	return 0;
}
EXPORT_SYMBOL(audmgr_open);

int audmgr_close(struct audmgr *am)
{
	return -EBUSY;
}
EXPORT_SYMBOL(audmgr_close);

int audmgr_enable(struct audmgr *am, struct audmgr_config *cfg)
{
	struct audmgr_enable_msg msg;
	int rc;

	if (am->state == STATE_ENABLED)
		return 0;

	if (am->state == STATE_DISABLING)
		pr_err("audmgr: state is DISABLING in enable?\n");
	am->state = STATE_ENABLING;

	msg.args.set_to_one = cpu_to_be32(1);
	msg.args.tx_sample_rate = cpu_to_be32(cfg->tx_rate);
	msg.args.rx_sample_rate = cpu_to_be32(cfg->rx_rate);
	msg.args.def_method = cpu_to_be32(cfg->def_method);
	msg.args.codec_type = cpu_to_be32(cfg->codec);
	msg.args.snd_method = cpu_to_be32(cfg->snd_method);
	msg.args.cb_func = cpu_to_be32(0x11111111);
	msg.args.client_data = cpu_to_be32(0x11223344);

	msm_rpc_setup_req(&msg.hdr, AUDMGR_PROG, msm_rpc_get_vers(am->ept),
			  AUDMGR_ENABLE_CLIENT);

	rc = msm_rpc_write(am->ept, &msg, sizeof(msg));
	if (rc < 0)
		return rc;

	rc = wait_event_timeout(am->wait, am->state != STATE_ENABLING, 15 * HZ);
	if (rc == 0) {
		pr_err("audmgr_enable: ARM9 did not reply to RPC am->state = %d\n", am->state);
		BUG();
	}
	if (am->state == STATE_ENABLED)
		return 0;

	pr_err("audmgr: unexpected state %d while enabling?!\n", am->state);
	return -ENODEV;
}
EXPORT_SYMBOL(audmgr_enable);

int audmgr_disable(struct audmgr *am)
{
	struct audmgr_disable_msg msg;
	int rc;

	if (am->state == STATE_DISABLED)
		return 0;

	msm_rpc_setup_req(&msg.hdr, AUDMGR_PROG, msm_rpc_get_vers(am->ept),
			  AUDMGR_DISABLE_CLIENT);
	msg.handle = cpu_to_be32(am->handle);

	am->state = STATE_DISABLING;

	rc = msm_rpc_write(am->ept, &msg, sizeof(msg));
	if (rc < 0)
		return rc;

	rc = wait_event_timeout(am->wait, am->state != STATE_DISABLING, 15 * HZ);
	if (rc == 0) {
		pr_err("audmgr_disable: ARM9 did not reply to RPC am->state = %d\n", am->state);
		BUG();
	}

	if (am->state == STATE_DISABLED)
		return 0;

	pr_err("audmgr: unexpected state %d while disabling?!\n", am->state);
	return -ENODEV;
}
EXPORT_SYMBOL(audmgr_disable);