/*
* Copyright (c) 2015, Sony Mobile Communications AB.
* Copyright (c) 2012-2013, The Linux Foundation. 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 and
* only 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/interrupt.h>
#include <linux/io.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/soc/qcom/smem.h>
#include <linux/wait.h>
#include <linux/rpmsg.h>
#include <linux/rpmsg/qcom_smd.h>
#include "rpmsg_internal.h"
/*
* The Qualcomm Shared Memory communication solution provides point-to-point
* channels for clients to send and receive streaming or packet based data.
*
* Each channel consists of a control item (channel info) and a ring buffer
* pair. The channel info carry information related to channel state, flow
* control and the offsets within the ring buffer.
*
* All allocated channels are listed in an allocation table, identifying the
* pair of items by name, type and remote processor.
*
* Upon creating a new channel the remote processor allocates channel info and
* ring buffer items from the smem heap and populate the allocation table. An
* interrupt is sent to the other end of the channel and a scan for new
* channels should be done. A channel never goes away, it will only change
* state.
*
* The remote processor signals it intent for bring up the communication
* channel by setting the state of its end of the channel to "opening" and
* sends out an interrupt. We detect this change and register a smd device to
* consume the channel. Upon finding a consumer we finish the handshake and the
* channel is up.
*
* Upon closing a channel, the remote processor will update the state of its
* end of the channel and signal us, we will then unregister any attached
* device and close our end of the channel.
*
* Devices attached to a channel can use the qcom_smd_send function to push
* data to the channel, this is done by copying the data into the tx ring
* buffer, updating the pointers in the channel info and signaling the remote
* processor.
*
* The remote processor does the equivalent when it transfer data and upon
* receiving the interrupt we check the channel info for new data and delivers
* this to the attached device. If the device is not ready to receive the data
* we leave it in the ring buffer for now.
*/
struct smd_channel_info;
struct smd_channel_info_pair;
struct smd_channel_info_word;
struct smd_channel_info_word_pair;
static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops;
#define SMD_ALLOC_TBL_COUNT 2
#define SMD_ALLOC_TBL_SIZE 64
/*
* This lists the various smem heap items relevant for the allocation table and
* smd channel entries.
*/
static const struct {
unsigned alloc_tbl_id;
unsigned info_base_id;
unsigned fifo_base_id;
} smem_items[SMD_ALLOC_TBL_COUNT] = {
{
.alloc_tbl_id = 13,
.info_base_id = 14,
.fifo_base_id = 338
},
{
.alloc_tbl_id = 266,
.info_base_id = 138,
.fifo_base_id = 202,
},
};
/**
* struct qcom_smd_edge - representing a remote processor
* @of_node: of_node handle for information related to this edge
* @edge_id: identifier of this edge
* @remote_pid: identifier of remote processor
* @irq: interrupt for signals on this edge
* @ipc_regmap: regmap handle holding the outgoing ipc register
* @ipc_offset: offset within @ipc_regmap of the register for ipc
* @ipc_bit: bit in the register at @ipc_offset of @ipc_regmap
* @channels: list of all channels detected on this edge
* @channels_lock: guard for modifications of @channels
* @allocated: array of bitmaps representing already allocated channels
* @smem_available: last available amount of smem triggering a channel scan
* @scan_work: work item for discovering new channels
* @state_work: work item for edge state changes
*/
struct qcom_smd_edge {
struct device dev;
const char *name;
struct device_node *of_node;
unsigned edge_id;
unsigned remote_pid;
int irq;
struct regmap *ipc_regmap;
int ipc_offset;
int ipc_bit;
struct list_head channels;
spinlock_t channels_lock;
DECLARE_BITMAP(allocated[SMD_ALLOC_TBL_COUNT], SMD_ALLOC_TBL_SIZE);
unsigned smem_available;
wait_queue_head_t new_channel_event;
struct work_struct scan_work;
struct work_struct state_work;
};
/*
* SMD channel states.
*/
enum smd_channel_state {
SMD_CHANNEL_CLOSED,
SMD_CHANNEL_OPENING,
SMD_CHANNEL_OPENED,
SMD_CHANNEL_FLUSHING,
SMD_CHANNEL_CLOSING,
SMD_CHANNEL_RESET,
SMD_CHANNEL_RESET_OPENING
};
struct qcom_smd_device {
struct rpmsg_device rpdev;
struct qcom_smd_edge *edge;
};
struct qcom_smd_endpoint {
struct rpmsg_endpoint ept;
struct qcom_smd_channel *qsch;
};
#define to_smd_device(_rpdev) container_of(_rpdev, struct qcom_smd_device, rpdev)
#define to_smd_edge(d) container_of(d, struct qcom_smd_edge, dev)
#define to_smd_endpoint(ept) container_of(ept, struct qcom_smd_endpoint, ept)
/**
* struct qcom_smd_channel - smd channel struct
* @edge: qcom_smd_edge this channel is living on
* @qsdev: reference to a associated smd client device
* @name: name of the channel
* @state: local state of the channel
* @remote_state: remote state of the channel
* @info: byte aligned outgoing/incoming channel info
* @info_word: word aligned outgoing/incoming channel info
* @tx_lock: lock to make writes to the channel mutually exclusive
* @fblockread_event: wakeup event tied to tx fBLOCKREADINTR
* @tx_fifo: pointer to the outgoing ring buffer
* @rx_fifo: pointer to the incoming ring buffer
* @fifo_size: size of each ring buffer
* @bounce_buffer: bounce buffer for reading wrapped packets
* @cb: callback function registered for this channel
* @recv_lock: guard for rx info modifications and cb pointer
* @pkt_size: size of the currently handled packet
* @list: lite entry for @channels in qcom_smd_edge
*/
struct qcom_smd_channel {
struct qcom_smd_edge *edge;
struct qcom_smd_endpoint *qsept;
bool registered;
char *name;
enum smd_channel_state state;
enum smd_channel_state remote_state;
struct smd_channel_info_pair *info;
struct smd_channel_info_word_pair *info_word;
struct mutex tx_lock;
wait_queue_head_t fblockread_event;
void *tx_fifo;
void *rx_fifo;
int fifo_size;
void *bounce_buffer;
spinlock_t recv_lock;
int pkt_size;
void *drvdata;
struct list_head list;
};
/*
* Format of the smd_info smem items, for byte aligned channels.
*/
struct smd_channel_info {
__le32 state;
u8 fDSR;
u8 fCTS;
u8 fCD;
u8 fRI;
u8 fHEAD;
u8 fTAIL;
u8 fSTATE;
u8 fBLOCKREADINTR;
__le32 tail;
__le32 head;
};
struct smd_channel_info_pair {
struct smd_channel_info tx;
struct smd_channel_info rx;
};
/*
* Format of the smd_info smem items, for word aligned channels.
*/
struct smd_channel_info_word {
__le32 state;
__le32 fDSR;
__le32 fCTS;
__le32 fCD;
__le32 fRI;
__le32 fHEAD;
__le32 fTAIL;
__le32 fSTATE;
__le32 fBLOCKREADINTR;
__le32 tail;
__le32 head;
};
struct smd_channel_info_word_pair {
struct smd_channel_info_word tx;
struct smd_channel_info_word rx;
};
#define GET_RX_CHANNEL_FLAG(channel, param) \
({ \
BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \
channel->info_word ? \
le32_to_cpu(channel->info_word->rx.param) : \
channel->info->rx.param; \
})
#define GET_RX_CHANNEL_INFO(channel, param) \
({ \
BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \
le32_to_cpu(channel->info_word ? \
channel->info_word->rx.param : \
channel->info->rx.param); \
})
#define SET_RX_CHANNEL_FLAG(channel, param, value) \
({ \
BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \
if (channel->info_word) \
channel->info_word->rx.param = cpu_to_le32(value); \
else \
channel->info->rx.param = value; \
})
#define SET_RX_CHANNEL_INFO(channel, param, value) \
({ \
BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \
if (channel->info_word) \
channel->info_word->rx.param = cpu_to_le32(value); \
else \
channel->info->rx.param = cpu_to_le32(value); \
})
#define GET_TX_CHANNEL_FLAG(channel, param) \
({ \
BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \
channel->info_word ? \
le32_to_cpu(channel->info_word->tx.param) : \
channel->info->tx.param; \
})
#define GET_TX_CHANNEL_INFO(channel, param) \
({ \
BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \
le32_to_cpu(channel->info_word ? \
channel->info_word->tx.param : \
channel->info->tx.param); \
})
#define SET_TX_CHANNEL_FLAG(channel, param, value) \
({ \
BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \
if (channel->info_word) \
channel->info_word->tx.param = cpu_to_le32(value); \
else \
channel->info->tx.param = value; \
})
#define SET_TX_CHANNEL_INFO(channel, param, value) \
({ \
BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \
if (channel->info_word) \
channel->info_word->tx.param = cpu_to_le32(value); \
else \
channel->info->tx.param = cpu_to_le32(value); \
})
/**
* struct qcom_smd_alloc_entry - channel allocation entry
* @name: channel name
* @cid: channel index
* @flags: channel flags and edge id
* @ref_count: reference count of the channel
*/
struct qcom_smd_alloc_entry {
u8 name[20];
__le32 cid;
__le32 flags;
__le32 ref_count;
} __packed;
#define SMD_CHANNEL_FLAGS_EDGE_MASK 0xff
#define SMD_CHANNEL_FLAGS_STREAM BIT(8)
#define SMD_CHANNEL_FLAGS_PACKET BIT(9)
/*
* Each smd packet contains a 20 byte header, with the first 4 being the length
* of the packet.
*/
#define SMD_PACKET_HEADER_LEN 20
/*
* Signal the remote processor associated with 'channel'.
*/
static void qcom_smd_signal_channel(struct qcom_smd_channel *channel)
{
struct qcom_smd_edge *edge = channel->edge;
regmap_write(edge->ipc_regmap, edge->ipc_offset, BIT(edge->ipc_bit));
}
/*
* Initialize the tx channel info
*/
static void qcom_smd_channel_reset(struct qcom_smd_channel *channel)
{
SET_TX_CHANNEL_INFO(channel, state, SMD_CHANNEL_CLOSED);
SET_TX_CHANNEL_FLAG(channel, fDSR, 0);
SET_TX_CHANNEL_FLAG(channel, fCTS, 0);
SET_TX_CHANNEL_FLAG(channel, fCD, 0);
SET_TX_CHANNEL_FLAG(channel, fRI, 0);
SET_TX_CHANNEL_FLAG(channel, fHEAD, 0);
SET_TX_CHANNEL_FLAG(channel, fTAIL, 0);
SET_TX_CHANNEL_FLAG(channel, fSTATE, 1);
SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1);
SET_TX_CHANNEL_INFO(channel, head, 0);
SET_RX_CHANNEL_INFO(channel, tail, 0);
qcom_smd_signal_channel(channel);
channel->state = SMD_CHANNEL_CLOSED;
channel->pkt_size = 0;
}
/*
* Set the callback for a channel, with appropriate locking
*/
static void qcom_smd_channel_set_callback(struct qcom_smd_channel *channel,
rpmsg_rx_cb_t cb)
{
struct rpmsg_endpoint *ept = &channel->qsept->ept;
unsigned long flags;
spin_lock_irqsave(&channel->recv_lock, flags);
ept->cb = cb;
spin_unlock_irqrestore(&channel->recv_lock, flags);
};
/*
* Calculate the amount of data available in the rx fifo
*/
static size_t qcom_smd_channel_get_rx_avail(struct qcom_smd_channel *channel)
{
unsigned head;
unsigned tail;
head = GET_RX_CHANNEL_INFO(channel, head);
tail = GET_RX_CHANNEL_INFO(channel, tail);
return (head - tail) & (channel->fifo_size - 1);
}
/*
* Set tx channel state and inform the remote processor
*/
static void qcom_smd_channel_set_state(struct qcom_smd_channel *channel,
int state)
{
struct qcom_smd_edge *edge = channel->edge;
bool is_open = state == SMD_CHANNEL_OPENED;
if (channel->state == state)
return;
dev_dbg(&edge->dev, "set_state(%s, %d)\n", channel->name, state);
SET_TX_CHANNEL_FLAG(channel, fDSR, is_open);
SET_TX_CHANNEL_FLAG(channel, fCTS, is_open);
SET_TX_CHANNEL_FLAG(channel, fCD, is_open);
SET_TX_CHANNEL_INFO(channel, state, state);
SET_TX_CHANNEL_FLAG(channel, fSTATE, 1);
channel->state = state;
qcom_smd_signal_channel(channel);
}
/*
* Copy count bytes of data using 32bit accesses, if that's required.
*/
static void smd_copy_to_fifo(void __iomem *dst,
const void *src,
size_t count,
bool word_aligned)
{
if (word_aligned) {
__iowrite32_copy(dst, src, count / sizeof(u32));
} else {
memcpy_toio(dst, src, count);
}
}
/*
* Copy count bytes of data using 32bit accesses, if that is required.
*/
static void smd_copy_from_fifo(void *dst,
const void __iomem *src,
size_t count,
bool word_aligned)
{
if (word_aligned) {
__ioread32_copy(dst, src, count / sizeof(u32));
} else {
memcpy_fromio(dst, src, count);
}
}
/*
* Read count bytes of data from the rx fifo into buf, but don't advance the
* tail.
*/
static size_t qcom_smd_channel_peek(struct qcom_smd_channel *channel,
void *buf, size_t count)
{
bool word_aligned;
unsigned tail;
size_t len;
word_aligned = channel->info_word;
tail = GET_RX_CHANNEL_INFO(channel, tail);
len = min_t(size_t, count, channel->fifo_size - tail);
if (len) {
smd_copy_from_fifo(buf,
channel->rx_fifo + tail,
len,
word_aligned);
}
if (len != count) {
smd_copy_from_fifo(buf + len,
channel->rx_fifo,
count - len,
word_aligned);
}
return count;
}
/*
* Advance the rx tail by count bytes.
*/
static void qcom_smd_channel_advance(struct qcom_smd_channel *channel,
size_t count)
{
unsigned tail;
tail = GET_RX_CHANNEL_INFO(channel, tail);
tail += count;
tail &= (channel->fifo_size - 1);
SET_RX_CHANNEL_INFO(channel, tail, tail);
}
/*
* Read out a single packet from the rx fifo and deliver it to the device
*/
static int qcom_smd_channel_recv_single(struct qcom_smd_channel *channel)
{
struct rpmsg_endpoint *ept = &channel->qsept->ept;
unsigned tail;
size_t len;
void *ptr;
int ret;
tail = GET_RX_CHANNEL_INFO(channel, tail);
/* Use bounce buffer if the data wraps */
if (tail + channel->pkt_size >= channel->fifo_size) {
ptr = channel->bounce_buffer;
len = qcom_smd_channel_peek(channel, ptr, channel->pkt_size);
} else {
ptr = channel->rx_fifo + tail;
len = channel->pkt_size;
}
ret = ept->cb(ept->rpdev, ptr, len, ept->priv, RPMSG_ADDR_ANY);
if (ret < 0)
return ret;
/* Only forward the tail if the client consumed the data */
qcom_smd_channel_advance(channel, len);
channel->pkt_size = 0;
return 0;
}
/*
* Per channel interrupt handling
*/
static bool qcom_smd_channel_intr(struct qcom_smd_channel *channel)
{
bool need_state_scan = false;
int remote_state;
__le32 pktlen;
int avail;
int ret;
/* Handle state changes */
remote_state = GET_RX_CHANNEL_INFO(channel, state);
if (remote_state != channel->remote_state) {
channel->remote_state = remote_state;
need_state_scan = true;
}
/* Indicate that we have seen any state change */
SET_RX_CHANNEL_FLAG(channel, fSTATE, 0);
/* Signal waiting qcom_smd_send() about the interrupt */
if (!GET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR))
wake_up_interruptible(&channel->fblockread_event);
/* Don't consume any data until we've opened the channel */
if (channel->state != SMD_CHANNEL_OPENED)
goto out;
/* Indicate that we've seen the new data */
SET_RX_CHANNEL_FLAG(channel, fHEAD, 0);
/* Consume data */
for (;;) {
avail = qcom_smd_channel_get_rx_avail(channel);
if (!channel->pkt_size && avail >= SMD_PACKET_HEADER_LEN) {
qcom_smd_channel_peek(channel, &pktlen, sizeof(pktlen));
qcom_smd_channel_advance(channel, SMD_PACKET_HEADER_LEN);
channel->pkt_size = le32_to_cpu(pktlen);
} else if (channel->pkt_size && avail >= channel->pkt_size) {
ret = qcom_smd_channel_recv_single(channel);
if (ret)
break;
} else {
break;
}
}
/* Indicate that we have seen and updated tail */
SET_RX_CHANNEL_FLAG(channel, fTAIL, 1);
/* Signal the remote that we've consumed the data (if requested) */
if (!GET_RX_CHANNEL_FLAG(channel, fBLOCKREADINTR)) {
/* Ensure ordering of channel info updates */
wmb();
qcom_smd_signal_channel(channel);
}
out:
return need_state_scan;
}
/*
* The edge interrupts are triggered by the remote processor on state changes,
* channel info updates or when new channels are created.
*/
static irqreturn_t qcom_smd_edge_intr(int irq, void *data)
{
struct qcom_smd_edge *edge = data;
struct qcom_smd_channel *channel;
unsigned available;
bool kick_scanner = false;
bool kick_state = false;
/*
* Handle state changes or data on each of the channels on this edge
*/
spin_lock(&edge->channels_lock);
list_for_each_entry(channel, &edge->channels, list) {
spin_lock(&channel->recv_lock);
kick_state |= qcom_smd_channel_intr(channel);
spin_unlock(&channel->recv_lock);
}
spin_unlock(&edge->channels_lock);
/*
* Creating a new channel requires allocating an smem entry, so we only
* have to scan if the amount of available space in smem have changed
* since last scan.
*/
available = qcom_smem_get_free_space(edge->remote_pid);
if (available != edge->smem_available) {
edge->smem_available = available;
kick_scanner = true;
}
if (kick_scanner)
schedule_work(&edge->scan_work);
if (kick_state)
schedule_work(&edge->state_work);
return IRQ_HANDLED;
}
/*
* Calculate how much space is available in the tx fifo.
*/
static size_t qcom_smd_get_tx_avail(struct qcom_smd_channel *channel)
{
unsigned head;
unsigned tail;
unsigned mask = channel->fifo_size - 1;
head = GET_TX_CHANNEL_INFO(channel, head);
tail = GET_TX_CHANNEL_INFO(channel, tail);
return mask - ((head - tail) & mask);
}
/*
* Write count bytes of data into channel, possibly wrapping in the ring buffer
*/
static int qcom_smd_write_fifo(struct qcom_smd_channel *channel,
const void *data,
size_t count)
{
bool word_aligned;
unsigned head;
size_t len;
word_aligned = channel->info_word;
head = GET_TX_CHANNEL_INFO(channel, head);
len = min_t(size_t, count, channel->fifo_size - head);
if (len) {
smd_copy_to_fifo(channel->tx_fifo + head,
data,
len,
word_aligned);
}
if (len != count) {
smd_copy_to_fifo(channel->tx_fifo,
data + len,
count - len,
word_aligned);
}
head += count;
head &= (channel->fifo_size - 1);
SET_TX_CHANNEL_INFO(channel, head, head);
return count;
}
/**
* qcom_smd_send - write data to smd channel
* @channel: channel handle
* @data: buffer of data to write
* @len: number of bytes to write
*
* This is a blocking write of len bytes into the channel's tx ring buffer and
* signal the remote end. It will sleep until there is enough space available
* in the tx buffer, utilizing the fBLOCKREADINTR signaling mechanism to avoid
* polling.
*/
static int __qcom_smd_send(struct qcom_smd_channel *channel, const void *data,
int len, bool wait)
{
__le32 hdr[5] = { cpu_to_le32(len), };
int tlen = sizeof(hdr) + len;
int ret;
/* Word aligned channels only accept word size aligned data */
if (channel->info_word && len % 4)
return -EINVAL;
/* Reject packets that are too big */
if (tlen >= channel->fifo_size)
return -EINVAL;
ret = mutex_lock_interruptible(&channel->tx_lock);
if (ret)
return ret;
while (qcom_smd_get_tx_avail(channel) < tlen) {
if (!wait) {
ret = -EAGAIN;
goto out;
}
if (channel->state != SMD_CHANNEL_OPENED) {
ret = -EPIPE;
goto out;
}
SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 0);
ret = wait_event_interruptible(channel->fblockread_event,
qcom_smd_get_tx_avail(channel) >= tlen ||
channel->state != SMD_CHANNEL_OPENED);
if (ret)
goto out;
SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1);
}
SET_TX_CHANNEL_FLAG(channel, fTAIL, 0);
qcom_smd_write_fifo(channel, hdr, sizeof(hdr));
qcom_smd_write_fifo(channel, data, len);
SET_TX_CHANNEL_FLAG(channel, fHEAD, 1);
/* Ensure ordering of channel info updates */
wmb();
qcom_smd_signal_channel(channel);
out:
mutex_unlock(&channel->tx_lock);
return ret;
}
/*
* Helper for opening a channel
*/
static int qcom_smd_channel_open(struct qcom_smd_channel *channel,
rpmsg_rx_cb_t cb)
{
size_t bb_size;
/*
* Packets are maximum 4k, but reduce if the fifo is smaller
*/
bb_size = min(channel->fifo_size, SZ_4K);
channel->bounce_buffer = kmalloc(bb_size, GFP_KERNEL);
if (!channel->bounce_buffer)
return -ENOMEM;
qcom_smd_channel_set_callback(channel, cb);
qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENING);
qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENED);
return 0;
}
/*
* Helper for closing and resetting a channel
*/
static void qcom_smd_channel_close(struct qcom_smd_channel *channel)
{
qcom_smd_channel_set_callback(channel, NULL);
kfree(channel->bounce_buffer);
channel->bounce_buffer = NULL;
qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED);
qcom_smd_channel_reset(channel);
}
static struct qcom_smd_channel *
qcom_smd_find_channel(struct qcom_smd_edge *edge, const char *name)
{
struct qcom_smd_channel *channel;
struct qcom_smd_channel *ret = NULL;
unsigned long flags;
spin_lock_irqsave(&edge->channels_lock, flags);
list_for_each_entry(channel, &edge->channels, list) {
if (!strcmp(channel->name, name)) {
ret = channel;
break;
}
}
spin_unlock_irqrestore(&edge->channels_lock, flags);
return ret;
}
static void __ept_release(struct kref *kref)
{
struct rpmsg_endpoint *ept = container_of(kref, struct rpmsg_endpoint,
refcount);
kfree(to_smd_endpoint(ept));
}
static struct rpmsg_endpoint *qcom_smd_create_ept(struct rpmsg_device *rpdev,
rpmsg_rx_cb_t cb, void *priv,
struct rpmsg_channel_info chinfo)
{
struct qcom_smd_endpoint *qsept;
struct qcom_smd_channel *channel;
struct qcom_smd_device *qsdev = to_smd_device(rpdev);
struct qcom_smd_edge *edge = qsdev->edge;
struct rpmsg_endpoint *ept;
const char *name = chinfo.name;
int ret;
/* Wait up to HZ for the channel to appear */
ret = wait_event_interruptible_timeout(edge->new_channel_event,
(channel = qcom_smd_find_channel(edge, name)) != NULL,
HZ);
if (!ret)
return NULL;
if (channel->state != SMD_CHANNEL_CLOSED) {
dev_err(&rpdev->dev, "channel %s is busy\n", channel->name);
return NULL;
}
qsept = kzalloc(sizeof(*qsept), GFP_KERNEL);
if (!qsept)
return NULL;
ept = &qsept->ept;
kref_init(&ept->refcount);
ept->rpdev = rpdev;
ept->cb = cb;
ept->priv = priv;
ept->ops = &qcom_smd_endpoint_ops;
channel->qsept = qsept;
qsept->qsch = channel;
ret = qcom_smd_channel_open(channel, cb);
if (ret)
goto free_ept;
return ept;
free_ept:
channel->qsept = NULL;
kref_put(&ept->refcount, __ept_release);
return NULL;
}
static void qcom_smd_destroy_ept(struct rpmsg_endpoint *ept)
{
struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
struct qcom_smd_channel *ch = qsept->qsch;
qcom_smd_channel_close(ch);
ch->qsept = NULL;
kref_put(&ept->refcount, __ept_release);
}
static int qcom_smd_send(struct rpmsg_endpoint *ept, void *data, int len)
{
struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
return __qcom_smd_send(qsept->qsch, data, len, true);
}
static int qcom_smd_trysend(struct rpmsg_endpoint *ept, void *data, int len)
{
struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
return __qcom_smd_send(qsept->qsch, data, len, false);
}
static unsigned int qcom_smd_poll(struct rpmsg_endpoint *ept,
struct file *filp, poll_table *wait)
{
struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
struct qcom_smd_channel *channel = qsept->qsch;
unsigned int mask = 0;
poll_wait(filp, &channel->fblockread_event, wait);
if (qcom_smd_get_tx_avail(channel) > 20)
mask |= POLLOUT | POLLWRNORM;
return mask;
}
/*
* Finds the device_node for the smd child interested in this channel.
*/
static struct device_node *qcom_smd_match_channel(struct device_node *edge_node,
const char *channel)
{
struct device_node *child;
const char *name;
const char *key;
int ret;
for_each_available_child_of_node(edge_node, child) {
key = "qcom,smd-channels";
ret = of_property_read_string(child, key, &name);
if (ret)
continue;
if (strcmp(name, channel) == 0)
return child;
}
return NULL;
}
static const struct rpmsg_device_ops qcom_smd_device_ops = {
.create_ept = qcom_smd_create_ept,
};
static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops = {
.destroy_ept = qcom_smd_destroy_ept,
.send = qcom_smd_send,
.trysend = qcom_smd_trysend,
.poll = qcom_smd_poll,
};
/*
* Create a smd client device for channel that is being opened.
*/
static int qcom_smd_create_device(struct qcom_smd_channel *channel)
{
struct qcom_smd_device *qsdev;
struct rpmsg_device *rpdev;
struct qcom_smd_edge *edge = channel->edge;
dev_dbg(&edge->dev, "registering '%s'\n", channel->name);
qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL);
if (!qsdev)
return -ENOMEM;
/* Link qsdev to our SMD edge */
qsdev->edge = edge;
/* Assign callbacks for rpmsg_device */
qsdev->rpdev.ops = &qcom_smd_device_ops;
/* Assign public information to the rpmsg_device */
rpdev = &qsdev->rpdev;
strncpy(rpdev->id.name, channel->name, RPMSG_NAME_SIZE);
rpdev->src = RPMSG_ADDR_ANY;
rpdev->dst = RPMSG_ADDR_ANY;
rpdev->dev.of_node = qcom_smd_match_channel(edge->of_node, channel->name);
rpdev->dev.parent = &edge->dev;
return rpmsg_register_device(rpdev);
}
static int qcom_smd_create_chrdev(struct qcom_smd_edge *edge)
{
struct qcom_smd_device *qsdev;
qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL);
if (!qsdev)
return -ENOMEM;
qsdev->edge = edge;
qsdev->rpdev.ops = &qcom_smd_device_ops;
qsdev->rpdev.dev.parent = &edge->dev;
return rpmsg_chrdev_register_device(&qsdev->rpdev);
}
/*
* Allocate the qcom_smd_channel object for a newly found smd channel,
* retrieving and validating the smem items involved.
*/
static struct qcom_smd_channel *qcom_smd_create_channel(struct qcom_smd_edge *edge,
unsigned smem_info_item,
unsigned smem_fifo_item,
char *name)
{
struct qcom_smd_channel *channel;
size_t fifo_size;
size_t info_size;
void *fifo_base;
void *info;
int ret;
channel = devm_kzalloc(&edge->dev, sizeof(*channel), GFP_KERNEL);
if (!channel)
return ERR_PTR(-ENOMEM);
channel->edge = edge;
channel->name = devm_kstrdup(&edge->dev, name, GFP_KERNEL);
if (!channel->name)
return ERR_PTR(-ENOMEM);
mutex_init(&channel->tx_lock);
spin_lock_init(&channel->recv_lock);
init_waitqueue_head(&channel->fblockread_event);
info = qcom_smem_get(edge->remote_pid, smem_info_item, &info_size);
if (IS_ERR(info)) {
ret = PTR_ERR(info);
goto free_name_and_channel;
}
/*
* Use the size of the item to figure out which channel info struct to
* use.
*/
if (info_size == 2 * sizeof(struct smd_channel_info_word)) {
channel->info_word = info;
} else if (info_size == 2 * sizeof(struct smd_channel_info)) {
channel->info = info;
} else {
dev_err(&edge->dev,
"channel info of size %zu not supported\n", info_size);
ret = -EINVAL;
goto free_name_and_channel;
}
fifo_base = qcom_smem_get(edge->remote_pid, smem_fifo_item, &fifo_size);
if (IS_ERR(fifo_base)) {
ret = PTR_ERR(fifo_base);
goto free_name_and_channel;
}
/* The channel consist of a rx and tx fifo of equal size */
fifo_size /= 2;
dev_dbg(&edge->dev, "new channel '%s' info-size: %zu fifo-size: %zu\n",
name, info_size, fifo_size);
channel->tx_fifo = fifo_base;
channel->rx_fifo = fifo_base + fifo_size;
channel->fifo_size = fifo_size;
qcom_smd_channel_reset(channel);
return channel;
free_name_and_channel:
devm_kfree(&edge->dev, channel->name);
devm_kfree(&edge->dev, channel);
return ERR_PTR(ret);
}
/*
* Scans the allocation table for any newly allocated channels, calls
* qcom_smd_create_channel() to create representations of these and add
* them to the edge's list of channels.
*/
static void qcom_channel_scan_worker(struct work_struct *work)
{
struct qcom_smd_edge *edge = container_of(work, struct qcom_smd_edge, scan_work);
struct qcom_smd_alloc_entry *alloc_tbl;
struct qcom_smd_alloc_entry *entry;
struct qcom_smd_channel *channel;
unsigned long flags;
unsigned fifo_id;
unsigned info_id;
int tbl;
int i;
u32 eflags, cid;
for (tbl = 0; tbl < SMD_ALLOC_TBL_COUNT; tbl++) {
alloc_tbl = qcom_smem_get(edge->remote_pid,
smem_items[tbl].alloc_tbl_id, NULL);
if (IS_ERR(alloc_tbl))
continue;
for (i = 0; i < SMD_ALLOC_TBL_SIZE; i++) {
entry = &alloc_tbl[i];
eflags = le32_to_cpu(entry->flags);
if (test_bit(i, edge->allocated[tbl]))
continue;
if (entry->ref_count == 0)
continue;
if (!entry->name[0])
continue;
if (!(eflags & SMD_CHANNEL_FLAGS_PACKET))
continue;
if ((eflags & SMD_CHANNEL_FLAGS_EDGE_MASK) != edge->edge_id)
continue;
cid = le32_to_cpu(entry->cid);
info_id = smem_items[tbl].info_base_id + cid;
fifo_id = smem_items[tbl].fifo_base_id + cid;
channel = qcom_smd_create_channel(edge, info_id, fifo_id, entry->name);
if (IS_ERR(channel))
continue;
spin_lock_irqsave(&edge->channels_lock, flags);
list_add(&channel->list, &edge->channels);
spin_unlock_irqrestore(&edge->channels_lock, flags);
dev_dbg(&edge->dev, "new channel found: '%s'\n", channel->name);
set_bit(i, edge->allocated[tbl]);
wake_up_interruptible(&edge->new_channel_event);
}
}
schedule_work(&edge->state_work);
}
/*
* This per edge worker scans smem for any new channels and register these. It
* then scans all registered channels for state changes that should be handled
* by creating or destroying smd client devices for the registered channels.
*
* LOCKING: edge->channels_lock only needs to cover the list operations, as the
* worker is killed before any channels are deallocated
*/
static void qcom_channel_state_worker(struct work_struct *work)
{
struct qcom_smd_channel *channel;
struct qcom_smd_edge *edge = container_of(work,
struct qcom_smd_edge,
state_work);
struct rpmsg_channel_info chinfo;
unsigned remote_state;
unsigned long flags;
/*
* Register a device for any closed channel where the remote processor
* is showing interest in opening the channel.
*/
spin_lock_irqsave(&edge->channels_lock, flags);
list_for_each_entry(channel, &edge->channels, list) {
if (channel->state != SMD_CHANNEL_CLOSED)
continue;
remote_state = GET_RX_CHANNEL_INFO(channel, state);
if (remote_state != SMD_CHANNEL_OPENING &&
remote_state != SMD_CHANNEL_OPENED)
continue;
if (channel->registered)
continue;
spin_unlock_irqrestore(&edge->channels_lock, flags);
qcom_smd_create_device(channel);
channel->registered = true;
spin_lock_irqsave(&edge->channels_lock, flags);
channel->registered = true;
}
/*
* Unregister the device for any channel that is opened where the
* remote processor is closing the channel.
*/
list_for_each_entry(channel, &edge->channels, list) {
if (channel->state != SMD_CHANNEL_OPENING &&
channel->state != SMD_CHANNEL_OPENED)
continue;
remote_state = GET_RX_CHANNEL_INFO(channel, state);
if (remote_state == SMD_CHANNEL_OPENING ||
remote_state == SMD_CHANNEL_OPENED)
continue;
spin_unlock_irqrestore(&edge->channels_lock, flags);
strncpy(chinfo.name, channel->name, sizeof(chinfo.name));
chinfo.src = RPMSG_ADDR_ANY;
chinfo.dst = RPMSG_ADDR_ANY;
rpmsg_unregister_device(&edge->dev, &chinfo);
channel->registered = false;
spin_lock_irqsave(&edge->channels_lock, flags);
}
spin_unlock_irqrestore(&edge->channels_lock, flags);
}
/*
* Parses an of_node describing an edge.
*/
static int qcom_smd_parse_edge(struct device *dev,
struct device_node *node,
struct qcom_smd_edge *edge)
{
struct device_node *syscon_np;
const char *key;
int irq;
int ret;
INIT_LIST_HEAD(&edge->channels);
spin_lock_init(&edge->channels_lock);
INIT_WORK(&edge->scan_work, qcom_channel_scan_worker);
INIT_WORK(&edge->state_work, qcom_channel_state_worker);
edge->of_node = of_node_get(node);
key = "qcom,smd-edge";
ret = of_property_read_u32(node, key, &edge->edge_id);
if (ret) {
dev_err(dev, "edge missing %s property\n", key);
return -EINVAL;
}
edge->remote_pid = QCOM_SMEM_HOST_ANY;
key = "qcom,remote-pid";
of_property_read_u32(node, key, &edge->remote_pid);
syscon_np = of_parse_phandle(node, "qcom,ipc", 0);
if (!syscon_np) {
dev_err(dev, "no qcom,ipc node\n");
return -ENODEV;
}
edge->ipc_regmap = syscon_node_to_regmap(syscon_np);
if (IS_ERR(edge->ipc_regmap))
return PTR_ERR(edge->ipc_regmap);
key = "qcom,ipc";
ret = of_property_read_u32_index(node, key, 1, &edge->ipc_offset);
if (ret < 0) {
dev_err(dev, "no offset in %s\n", key);
return -EINVAL;
}
ret = of_property_read_u32_index(node, key, 2, &edge->ipc_bit);
if (ret < 0) {
dev_err(dev, "no bit in %s\n", key);
return -EINVAL;
}
ret = of_property_read_string(node, "label", &edge->name);
if (ret < 0)
edge->name = node->name;
irq = irq_of_parse_and_map(node, 0);
if (irq < 0) {
dev_err(dev, "required smd interrupt missing\n");
return -EINVAL;
}
ret = devm_request_irq(dev, irq,
qcom_smd_edge_intr, IRQF_TRIGGER_RISING,
node->name, edge);
if (ret) {
dev_err(dev, "failed to request smd irq\n");
return ret;
}
edge->irq = irq;
return 0;
}
/*
* Release function for an edge.
* Reset the state of each associated channel and free the edge context.
*/
static void qcom_smd_edge_release(struct device *dev)
{
struct qcom_smd_channel *channel;
struct qcom_smd_edge *edge = to_smd_edge(dev);
list_for_each_entry(channel, &edge->channels, list) {
SET_RX_CHANNEL_INFO(channel, state, SMD_CHANNEL_CLOSED);
SET_RX_CHANNEL_INFO(channel, head, 0);
SET_RX_CHANNEL_INFO(channel, tail, 0);
}
kfree(edge);
}
static ssize_t rpmsg_name_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct qcom_smd_edge *edge = to_smd_edge(dev);
return sprintf(buf, "%s\n", edge->name);
}
static DEVICE_ATTR_RO(rpmsg_name);
static struct attribute *qcom_smd_edge_attrs[] = {
&dev_attr_rpmsg_name.attr,
NULL
};
ATTRIBUTE_GROUPS(qcom_smd_edge);
/**
* qcom_smd_register_edge() - register an edge based on an device_node
* @parent: parent device for the edge
* @node: device_node describing the edge
*
* Returns an edge reference, or negative ERR_PTR() on failure.
*/
struct qcom_smd_edge *qcom_smd_register_edge(struct device *parent,
struct device_node *node)
{
struct qcom_smd_edge *edge;
int ret;
edge = kzalloc(sizeof(*edge), GFP_KERNEL);
if (!edge)
return ERR_PTR(-ENOMEM);
init_waitqueue_head(&edge->new_channel_event);
edge->dev.parent = parent;
edge->dev.release = qcom_smd_edge_release;
edge->dev.groups = qcom_smd_edge_groups;
dev_set_name(&edge->dev, "%s:%s", dev_name(parent), node->name);
ret = device_register(&edge->dev);
if (ret) {
pr_err("failed to register smd edge\n");
return ERR_PTR(ret);
}
ret = qcom_smd_parse_edge(&edge->dev, node, edge);
if (ret) {
dev_err(&edge->dev, "failed to parse smd edge\n");
goto unregister_dev;
}
ret = qcom_smd_create_chrdev(edge);
if (ret) {
dev_err(&edge->dev, "failed to register chrdev for edge\n");
goto unregister_dev;
}
schedule_work(&edge->scan_work);
return edge;
unregister_dev:
put_device(&edge->dev);
return ERR_PTR(ret);
}
EXPORT_SYMBOL(qcom_smd_register_edge);
static int qcom_smd_remove_device(struct device *dev, void *data)
{
device_unregister(dev);
return 0;
}
/**
* qcom_smd_unregister_edge() - release an edge and its children
* @edge: edge reference acquired from qcom_smd_register_edge
*/
int qcom_smd_unregister_edge(struct qcom_smd_edge *edge)
{
int ret;
disable_irq(edge->irq);
cancel_work_sync(&edge->scan_work);
cancel_work_sync(&edge->state_work);
ret = device_for_each_child(&edge->dev, NULL, qcom_smd_remove_device);
if (ret)
dev_warn(&edge->dev, "can't remove smd device: %d\n", ret);
device_unregister(&edge->dev);
return 0;
}
EXPORT_SYMBOL(qcom_smd_unregister_edge);
static int qcom_smd_probe(struct platform_device *pdev)
{
struct device_node *node;
void *p;
/* Wait for smem */
p = qcom_smem_get(QCOM_SMEM_HOST_ANY, smem_items[0].alloc_tbl_id, NULL);
if (PTR_ERR(p) == -EPROBE_DEFER)
return PTR_ERR(p);
for_each_available_child_of_node(pdev->dev.of_node, node)
qcom_smd_register_edge(&pdev->dev, node);
return 0;
}
static int qcom_smd_remove_edge(struct device *dev, void *data)
{
struct qcom_smd_edge *edge = to_smd_edge(dev);
return qcom_smd_unregister_edge(edge);
}
/*
* Shut down all smd clients by making sure that each edge stops processing
* events and scanning for new channels, then call destroy on the devices.
*/
static int qcom_smd_remove(struct platform_device *pdev)
{
int ret;
ret = device_for_each_child(&pdev->dev, NULL, qcom_smd_remove_edge);
if (ret)
dev_warn(&pdev->dev, "can't remove smd device: %d\n", ret);
return ret;
}
static const struct of_device_id qcom_smd_of_match[] = {
{ .compatible = "qcom,smd" },
{}
};
MODULE_DEVICE_TABLE(of, qcom_smd_of_match);
static struct platform_driver qcom_smd_driver = {
.probe = qcom_smd_probe,
.remove = qcom_smd_remove,
.driver = {
.name = "qcom-smd",
.of_match_table = qcom_smd_of_match,
},
};
static int __init qcom_smd_init(void)
{
return platform_driver_register(&qcom_smd_driver);
}
subsys_initcall(qcom_smd_init);
static void __exit qcom_smd_exit(void)
{
platform_driver_unregister(&qcom_smd_driver);
}
module_exit(qcom_smd_exit);
MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>");
MODULE_DESCRIPTION("Qualcomm Shared Memory Driver");
MODULE_LICENSE("GPL v2");
