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/*
* Intel SST generic IPC Support
*
* Copyright (C) 2015, Intel Corporation. All rights reserved.
*
* 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.
*
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/wait.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/kthread.h>
#include <sound/asound.h>
#include "sst-dsp.h"
#include "sst-dsp-priv.h"
#include "sst-ipc.h"
/* IPC message timeout (msecs) */
#define IPC_TIMEOUT_MSECS 300
#define IPC_EMPTY_LIST_SIZE 8
/* locks held by caller */
static struct ipc_message *msg_get_empty(struct sst_generic_ipc *ipc)
{
struct ipc_message *msg = NULL;
if (!list_empty(&ipc->empty_list)) {
msg = list_first_entry(&ipc->empty_list, struct ipc_message,
list);
list_del(&msg->list);
}
return msg;
}
static int tx_wait_done(struct sst_generic_ipc *ipc,
struct ipc_message *msg, void *rx_data)
{
unsigned long flags;
int ret;
/* wait for DSP completion (in all cases atm inc pending) */
ret = wait_event_timeout(msg->waitq, msg->complete,
msecs_to_jiffies(IPC_TIMEOUT_MSECS));
spin_lock_irqsave(&ipc->dsp->spinlock, flags);
if (ret == 0) {
if (ipc->ops.shim_dbg != NULL)
ipc->ops.shim_dbg(ipc, "message timeout");
list_del(&msg->list);
ret = -ETIMEDOUT;
} else {
/* copy the data returned from DSP */
if (msg->rx_size)
memcpy(rx_data, msg->rx_data, msg->rx_size);
ret = msg->errno;
}
list_add_tail(&msg->list, &ipc->empty_list);
spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
return ret;
}
static int ipc_tx_message(struct sst_generic_ipc *ipc, u64 header,
void *tx_data, size_t tx_bytes, void *rx_data,
size_t rx_bytes, int wait)
{
struct ipc_message *msg;
unsigned long flags;
spin_lock_irqsave(&ipc->dsp->spinlock, flags);
msg = msg_get_empty(ipc);
if (msg == NULL) {
spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
return -EBUSY;
}
msg->header = header;
msg->tx_size = tx_bytes;
msg->rx_size = rx_bytes;
msg->wait = wait;
msg->errno = 0;
msg->pending = false;
msg->complete = false;
if ((tx_bytes) && (ipc->ops.tx_data_copy != NULL))
ipc->ops.tx_data_copy(msg, tx_data, tx_bytes);
list_add_tail(&msg->list, &ipc->tx_list);
spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
queue_kthread_work(&ipc->kworker, &ipc->kwork);
if (wait)
return tx_wait_done(ipc, msg, rx_data);
else
return 0;
}
static int msg_empty_list_init(struct sst_generic_ipc *ipc)
{
int i;
ipc->msg = kzalloc(sizeof(struct ipc_message) *
IPC_EMPTY_LIST_SIZE, GFP_KERNEL);
if (ipc->msg == NULL)
return -ENOMEM;
for (i = 0; i < IPC_EMPTY_LIST_SIZE; i++) {
init_waitqueue_head(&ipc->msg[i].waitq);
list_add(&ipc->msg[i].list, &ipc->empty_list);
}
return 0;
}
static void ipc_tx_msgs(struct kthread_work *work)
{
struct sst_generic_ipc *ipc =
container_of(work, struct sst_generic_ipc, kwork);
struct ipc_message *msg;
unsigned long flags;
u64 ipcx;
spin_lock_irqsave(&ipc->dsp->spinlock, flags);
if (list_empty(&ipc->tx_list) || ipc->pending) {
spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
return;
}
/* if the DSP is busy, we will TX messages after IRQ.
* also postpone if we are in the middle of procesing completion irq*/
ipcx = sst_dsp_shim_read_unlocked(ipc->dsp, SST_IPCX);
if (ipcx & (SST_IPCX_BUSY | SST_IPCX_DONE)) {
spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
return;
}
msg = list_first_entry(&ipc->tx_list, struct ipc_message, list);
list_move(&msg->list, &ipc->rx_list);
if (ipc->ops.tx_msg != NULL)
ipc->ops.tx_msg(ipc, msg);
spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
}
int sst_ipc_tx_message_wait(struct sst_generic_ipc *ipc, u64 header,
void *tx_data, size_t tx_bytes, void *rx_data, size_t rx_bytes)
{
return ipc_tx_message(ipc, header, tx_data, tx_bytes,
rx_data, rx_bytes, 1);
}
EXPORT_SYMBOL_GPL(sst_ipc_tx_message_wait);
int sst_ipc_tx_message_nowait(struct sst_generic_ipc *ipc, u64 header,
void *tx_data, size_t tx_bytes)
{
return ipc_tx_message(ipc, header, tx_data, tx_bytes,
NULL, 0, 0);
}
EXPORT_SYMBOL_GPL(sst_ipc_tx_message_nowait);
struct ipc_message *sst_ipc_reply_find_msg(struct sst_generic_ipc *ipc,
u64 header)
{
struct ipc_message *msg;
u64 mask;
if (ipc->ops.reply_msg_match != NULL)
header = ipc->ops.reply_msg_match(header, &mask);
if (list_empty(&ipc->rx_list)) {
dev_err(ipc->dev, "error: rx list empty but received 0x%llx\n",
header);
return NULL;
}
list_for_each_entry(msg, &ipc->rx_list, list) {
if ((msg->header & mask) == header)
return msg;
}
return NULL;
}
EXPORT_SYMBOL_GPL(sst_ipc_reply_find_msg);
/* locks held by caller */
void sst_ipc_tx_msg_reply_complete(struct sst_generic_ipc *ipc,
struct ipc_message *msg)
{
msg->complete = true;
if (!msg->wait)
list_add_tail(&msg->list, &ipc->empty_list);
else
wake_up(&msg->waitq);
}
EXPORT_SYMBOL_GPL(sst_ipc_tx_msg_reply_complete);
void sst_ipc_drop_all(struct sst_generic_ipc *ipc)
{
struct ipc_message *msg, *tmp;
unsigned long flags;
int tx_drop_cnt = 0, rx_drop_cnt = 0;
/* drop all TX and Rx messages before we stall + reset DSP */
spin_lock_irqsave(&ipc->dsp->spinlock, flags);
list_for_each_entry_safe(msg, tmp, &ipc->tx_list, list) {
list_move(&msg->list, &ipc->empty_list);
tx_drop_cnt++;
}
list_for_each_entry_safe(msg, tmp, &ipc->rx_list, list) {
list_move(&msg->list, &ipc->empty_list);
rx_drop_cnt++;
}
spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
if (tx_drop_cnt || rx_drop_cnt)
dev_err(ipc->dev, "dropped IPC msg RX=%d, TX=%d\n",
tx_drop_cnt, rx_drop_cnt);
}
EXPORT_SYMBOL_GPL(sst_ipc_drop_all);
int sst_ipc_init(struct sst_generic_ipc *ipc)
{
int ret;
INIT_LIST_HEAD(&ipc->tx_list);
INIT_LIST_HEAD(&ipc->rx_list);
INIT_LIST_HEAD(&ipc->empty_list);
init_waitqueue_head(&ipc->wait_txq);
ret = msg_empty_list_init(ipc);
if (ret < 0)
return -ENOMEM;
/* start the IPC message thread */
init_kthread_worker(&ipc->kworker);
ipc->tx_thread = kthread_run(kthread_worker_fn,
&ipc->kworker, "%s",
dev_name(ipc->dev));
if (IS_ERR(ipc->tx_thread)) {
dev_err(ipc->dev, "error: failed to create message TX task\n");
ret = PTR_ERR(ipc->tx_thread);
kfree(ipc->msg);
return ret;
}
init_kthread_work(&ipc->kwork, ipc_tx_msgs);
return 0;
}
EXPORT_SYMBOL_GPL(sst_ipc_init);
void sst_ipc_fini(struct sst_generic_ipc *ipc)
{
if (ipc->tx_thread)
kthread_stop(ipc->tx_thread);
if (ipc->msg)
kfree(ipc->msg);
}
EXPORT_SYMBOL_GPL(sst_ipc_fini);
/* Module information */
MODULE_AUTHOR("Jin Yao");
MODULE_DESCRIPTION("Intel SST IPC generic");
MODULE_LICENSE("GPL v2");
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