This patch implements the shared memory based communication system found on all
Qualcomm platforms. SMD was originally used to communicate with the modem but
has grown to be part of power management as well as the various DSPs etc found
in Qualcomm platforms.
The code depends on the SMEM implementation found here:
https://patchwork.kernel.org/patch/6160431/
Bjorn Andersson (2):
soc: qcom: Add device tree binding for Shared Memory Device
soc: qcom: Add Shared Memory Driver
.../devicetree/bindings/soc/qcom/qcom,smd.txt | 78 ++
drivers/soc/qcom/Kconfig | 8 +
drivers/soc/qcom/Makefile | 1 +
drivers/soc/qcom/smd.c | 1263 ++++++++++++++++++++
include/linux/soc/qcom/smd.h | 47 +
5 files changed, 1397 insertions(+)
create mode 100644 Documentation/devicetree/bindings/soc/qcom/qcom,smd.txt
create mode 100644 drivers/soc/qcom/smd.c
create mode 100644 include/linux/soc/qcom/smd.h
--
1.8.2.2
Add device tree binding documentation for the Qualcomm Shared Memory
Device, used for communication between the various CPUs in the Qualcomm
SoCs.
Signed-off-by: Bjorn Andersson <[email protected]>
---
.../devicetree/bindings/soc/qcom/qcom,smd.txt | 78 ++++++++++++++++++++++
1 file changed, 78 insertions(+)
create mode 100644 Documentation/devicetree/bindings/soc/qcom/qcom,smd.txt
diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,smd.txt b/Documentation/devicetree/bindings/soc/qcom/qcom,smd.txt
new file mode 100644
index 0000000..0fdb7f9d
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/qcom/qcom,smd.txt
@@ -0,0 +1,78 @@
+Qualcomm Shared Memory Driver (SMD) binding
+
+This binding describes the Qualcomm Shared Memory Driver, a fifo based
+communication channel for sending data between the various subsystems in
+Qualcomm platforms.
+
+- compatible:
+ Usage: required
+ Value type: <stringlist>
+ Definition: must be "qcom,smd"
+
+= EDGES
+
+Each subnode of the SMD node represents a remote subsystem or a remote
+processor of some sort - or in SMD language an "edge". The name of the
+edges are not important.
+
+- interrupts:
+ Usage: required
+ Value type: <prop-encoded-array>
+ Definition: should specify the IRQ used by the remote processor to
+ signal this processor about communication related updates
+
+- qcom,ipc:
+ Usage: required
+ Value type: <prop-encoded-array>
+ Definition: three entries specifying the outgoing ipc bit used for
+ signaling the remote processor:
+ - phandle to a syscon node representing the apcs registers
+ - u32 representing offset to the register within the syscon
+ - u32 representing the ipc bit within the register
+
+- qcom,smd-edge:
+ Usage: required
+ Value type: <u32>
+ Definition: the identifier representing the remote processor in the
+ smd channel allocation table
+
+= SMD DEVICES
+
+In turn, subnodes of the "edges" represent devices tied to SMD channels on that
+"edge". The names of the devices are not important. The properties of these
+nodes are defined by the individual bindings for the SMD devices - but must
+contain the following property:
+
+- qcom,smd-channels:
+ Usage: required
+ Value type: <stringlist>
+ Definition: a list of channels tied to this device, used for matching
+ the device to channels
+
+= EXAMPLE
+
+The following example represents a smd node, with one edge representing the
+"rpm" subsystem. For the "rpm" subsystem we have a device tied to the
+"rpm_request" channel.
+
+ apcs: syscon@f9011000 {
+ compatible = "syscon";
+ reg = <0xf9011000 0x1000>;
+ };
+
+ smd {
+ compatible = "qcom,smd";
+
+ rpm {
+ interrupts = <0 168 1>;
+ qcom,ipc = <&apcs 8 0>;
+ qcom,smd-edge = <15>;
+
+ rpm_requests {
+ compatible = "qcom,rpm-msm8974";
+ qcom,smd-channels = "rpm_requests";
+
+ ...
+ };
+ };
+ };
--
1.8.2.2
This adds the Qualcomm Shared Memory Driver (SMD) providing
communication channels to remote processors, ontop of SMEM.
Signed-off-by: Bjorn Andersson <[email protected]>
---
Note that this code depends on:
https://patchwork.kernel.org/patch/6160431/
drivers/soc/qcom/Kconfig | 8 +
drivers/soc/qcom/Makefile | 1 +
drivers/soc/qcom/smd.c | 1263 ++++++++++++++++++++++++++++++++++++++++++
include/linux/soc/qcom/smd.h | 47 ++
4 files changed, 1319 insertions(+)
create mode 100644 drivers/soc/qcom/smd.c
create mode 100644 include/linux/soc/qcom/smd.h
diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index b5783a4..8e83876 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -9,6 +9,14 @@ config QCOM_GSBI
functions for connecting the underlying serial UART, SPI, and I2C
devices to the output pins.
+config QCOM_SMD
+ tristate "Qualcomm Shared Memory Driver (SMD)"
+ depends on QCOM_SMEM
+ help
+ Say y here to enable support for the Qualcomm Shared Memory Driver
+ providing communication channels to remote processors in Qualcomm
+ platforms.
+
config QCOM_SMEM
tristate "Qualcomm Shared Memory Manager (SMEM)"
depends on ARCH_QCOM
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index 91a61fb..aff2264 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -1,2 +1,3 @@
obj-$(CONFIG_QCOM_GSBI) += qcom_gsbi.o
+obj-$(CONFIG_QCOM_SMD) += smd.o
obj-$(CONFIG_QCOM_SMEM) += smem.o
diff --git a/drivers/soc/qcom/smd.c b/drivers/soc/qcom/smd.c
new file mode 100644
index 0000000..e7d4891
--- /dev/null
+++ b/drivers/soc/qcom/smd.c
@@ -0,0 +1,1263 @@
+/*
+ * 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/delay.h>
+#include <linux/hwspinlock.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/memblock.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/soc/qcom/smd.h>
+#include <linux/soc/qcom/smem.h>
+#include <linux/wait.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_word;
+
+#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 = 14,
+ .info_base_id = 266,
+ .fifo_base_id = 202,
+ },
+};
+
+/**
+ * struct qcom_smd_edge - representing a remote processor
+ * @smd: handle to qcom_smd
+ * @of_node: of_node handle for information related to this edge
+ * @edge_id: identifier of this edge
+ * @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
+ * @need_rescan: flag that the @work needs to scan smem for new channels
+ * @smem_available: last available amount of smem triggering a channel scan
+ * @work: work item for edge house keeping
+ */
+struct qcom_smd_edge {
+ struct qcom_smd *smd;
+ struct device_node *of_node;
+ unsigned edge_id;
+
+ int irq;
+
+ struct regmap *ipc_regmap;
+ int ipc_offset;
+ int ipc_bit;
+
+ struct list_head channels;
+ spinlock_t channels_lock;
+
+ bool need_rescan;
+ unsigned smem_available;
+
+ struct work_struct 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_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
+ * @tx_info: byte aligned outgoing channel info
+ * @rx_info: byte aligned incoming channel info
+ * @tx_info_word: word aligned outgoing channel info
+ * @rx_info_word: word aligned 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_device *qsdev;
+
+ char *name;
+ enum smd_channel_state state;
+ enum smd_channel_state remote_state;
+
+ struct smd_channel_info *tx_info;
+ struct smd_channel_info *rx_info;
+
+ struct smd_channel_info_word *tx_info_word;
+ struct smd_channel_info_word *rx_info_word;
+
+ struct mutex tx_lock;
+ wait_queue_head_t fblockread_event;
+
+ void *tx_fifo;
+ void *rx_fifo;
+ int fifo_size;
+
+ void *bounce_buffer;
+ int (*cb)(struct qcom_smd_device *, const void *, size_t);
+
+ spinlock_t recv_lock;
+
+ int pkt_size;
+
+ struct list_head list;
+};
+
+/**
+ * struct qcom_smd - smd struct
+ * @dev: device struct
+ * @allocated: bitmap representing already allocated channels
+ * @alloc_tbl: pointer(s) to the allocation table(s)
+ * @alloc_tbl_entries: number of actual allocation entries found
+ * @num_edges: number of entries in @edges
+ * @edges: array of edges to be handled
+ */
+struct qcom_smd {
+ struct device *dev;
+
+ DECLARE_BITMAP(allocated, SMD_ALLOC_TBL_COUNT * SMD_ALLOC_TBL_SIZE);
+ struct qcom_smd_alloc_entry *alloc_tbl[SMD_ALLOC_TBL_COUNT];
+ unsigned alloc_tbl_entries;
+
+ unsigned num_edges;
+ struct qcom_smd_edge edges[0];
+};
+
+/*
+ * Format of the smd_info smem items, for byte aligned channels.
+ */
+struct smd_channel_info {
+ u32 state;
+ u8 fDSR;
+ u8 fCTS;
+ u8 fCD;
+ u8 fRI;
+ u8 fHEAD;
+ u8 fTAIL;
+ u8 fSTATE;
+ u8 fBLOCKREADINTR;
+ u32 tail;
+ u32 head;
+};
+
+/*
+ * Format of the smd_info smem items, for word aligned channels.
+ */
+struct smd_channel_info_word {
+ u32 state;
+ u32 fDSR;
+ u32 fCTS;
+ u32 fCD;
+ u32 fRI;
+ u32 fHEAD;
+ u32 fTAIL;
+ u32 fSTATE;
+ u32 fBLOCKREADINTR;
+ u32 tail;
+ u32 head;
+};
+
+#define GET_RX_CHANNEL_INFO(channel, param) \
+ (channel->rx_info_word ? \
+ channel->rx_info_word->param : \
+ channel->rx_info->param)
+
+#define SET_RX_CHANNEL_INFO(channel, param, value) \
+ (channel->rx_info_word ? \
+ (channel->rx_info_word->param = value) : \
+ (channel->rx_info->param = value))
+
+#define GET_TX_CHANNEL_INFO(channel, param) \
+ (channel->rx_info_word ? \
+ channel->tx_info_word->param : \
+ channel->tx_info->param)
+
+#define SET_TX_CHANNEL_INFO(channel, param, value) \
+ (channel->rx_info_word ? \
+ (channel->tx_info_word->param = value) : \
+ (channel->tx_info->param = 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];
+ u32 cid;
+ u32 flags;
+ u32 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_INFO(channel, fDSR, 0);
+ SET_TX_CHANNEL_INFO(channel, fCTS, 0);
+ SET_TX_CHANNEL_INFO(channel, fCD, 0);
+ SET_TX_CHANNEL_INFO(channel, fRI, 0);
+ SET_TX_CHANNEL_INFO(channel, fHEAD, 0);
+ SET_TX_CHANNEL_INFO(channel, fTAIL, 0);
+ SET_TX_CHANNEL_INFO(channel, fSTATE, 1);
+ SET_TX_CHANNEL_INFO(channel, fBLOCKREADINTR, 0);
+ SET_TX_CHANNEL_INFO(channel, head, 0);
+ SET_TX_CHANNEL_INFO(channel, tail, 0);
+
+ qcom_smd_signal_channel(channel);
+
+ channel->state = SMD_CHANNEL_CLOSED;
+ channel->pkt_size = 0;
+}
+
+/*
+ * 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->smd->dev, "set_state(%s, %d)\n", channel->name, state);
+
+ SET_TX_CHANNEL_INFO(channel, fDSR, is_open);
+ SET_TX_CHANNEL_INFO(channel, fCTS, is_open);
+ SET_TX_CHANNEL_INFO(channel, fCD, is_open);
+
+ SET_TX_CHANNEL_INFO(channel, state, state);
+ SET_TX_CHANNEL_INFO(channel, fSTATE, 1);
+
+ channel->state = state;
+ qcom_smd_signal_channel(channel);
+}
+
+/*
+ * 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)
+{
+ unsigned tail;
+ size_t len;
+
+ tail = GET_RX_CHANNEL_INFO(channel, tail);
+
+ len = min(count, channel->fifo_size - tail);
+ if (len)
+ memcpy(buf, channel->rx_fifo + tail, len);
+
+ if (len != count)
+ memcpy(buf + len, channel->rx_fifo, count - len);
+
+ 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 qcom_smd_device *qsdev = channel->qsdev;
+ unsigned tail;
+ size_t len;
+ void *ptr;
+ int ret;
+
+ if (!channel->cb)
+ return 0;
+
+ 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 = channel->cb(qsdev, ptr, len);
+ 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;
+ u32 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_INFO(channel, fSTATE, 0);
+
+ /* Signal waiting qcom_smd_send() about the interrupt */
+ if (!GET_TX_CHANNEL_INFO(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_INFO(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 = 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_INFO(channel, fTAIL, 1);
+
+ /* Signal the remote that we've consumed the data (if requested) */
+ if (!GET_RX_CHANNEL_INFO(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_worker = 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_worker |= 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->edge_id);
+ if (available != edge->smem_available) {
+ edge->smem_available = available;
+ edge->need_rescan = true;
+ kick_worker = true;
+ }
+
+ if (kick_worker)
+ schedule_work(&edge->work);
+
+ return IRQ_HANDLED;
+}
+
+/*
+ * Delivers any outstanding packets in the rx fifo, can be used after probe of
+ * the clients to deliver any packets that wasn't delivered before the client
+ * was setup.
+ */
+static void qcom_smd_channel_resume(struct qcom_smd_channel *channel)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&channel->recv_lock, flags);
+ qcom_smd_channel_intr(channel);
+ spin_unlock_irqrestore(&channel->recv_lock, flags);
+}
+
+/*
+ * 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)
+{
+ unsigned head;
+ size_t len;
+
+ head = GET_TX_CHANNEL_INFO(channel, head);
+
+ len = min(count, channel->fifo_size - head);
+ if (len)
+ memcpy(channel->tx_fifo + head, data, len);
+
+ if (len != count)
+ memcpy(channel->tx_fifo, data + len, count - len);
+
+ 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.
+ */
+int qcom_smd_send(struct qcom_smd_channel *channel, const void *data, int len)
+{
+ u32 hdr[5] = {len,};
+ int tlen = sizeof(hdr) + len;
+ int ret;
+
+ ret = mutex_lock_interruptible(&channel->tx_lock);
+ if (ret)
+ return ret;
+
+ while (qcom_smd_get_tx_avail(channel) < tlen) {
+ if (channel->state != SMD_CHANNEL_OPENED) {
+ ret = -EPIPE;
+ goto out;
+ }
+
+ SET_TX_CHANNEL_INFO(channel, fBLOCKREADINTR, 1);
+
+ 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_INFO(channel, fBLOCKREADINTR, 0);
+ }
+
+ SET_TX_CHANNEL_INFO(channel, fTAIL, 0);
+
+ qcom_smd_write_fifo(channel, hdr, sizeof(hdr));
+ qcom_smd_write_fifo(channel, data, len);
+
+ SET_TX_CHANNEL_INFO(channel, fHEAD, 1);
+
+ /* Ensure ordering of channel info updates */
+ wmb();
+
+ qcom_smd_signal_channel(channel);
+
+out:
+ mutex_unlock(&channel->tx_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL(qcom_smd_send);
+
+static struct qcom_smd_device *to_smd_device(struct device *dev)
+{
+ return container_of(dev, struct qcom_smd_device, dev);
+}
+
+static struct qcom_smd_driver *to_smd_driver(struct device *dev)
+{
+ struct qcom_smd_device *qsdev = to_smd_device(dev);
+
+ return container_of(qsdev->dev.driver, struct qcom_smd_driver, driver);
+}
+
+static int qcom_smd_dev_match(struct device *dev, struct device_driver *drv)
+{
+ return of_driver_match_device(dev, drv);
+}
+
+/*
+ * Probe the smd client.
+ *
+ * The remote side have indicated that it want the channel to be opened, so
+ * complete the state handshake and probe our client driver.
+ */
+static int qcom_smd_dev_probe(struct device *dev)
+{
+ struct qcom_smd_device *qsdev = to_smd_device(dev);
+ struct qcom_smd_driver *qsdrv = to_smd_driver(dev);
+ struct qcom_smd_channel *channel = qsdev->channel;
+ size_t bb_size;
+ int ret;
+
+ /*
+ * Packets are maximum 4k, but reduce if the fifo is smaller
+ */
+ bb_size = min(channel->fifo_size, 4096);
+ channel->bounce_buffer = kmalloc(bb_size, GFP_KERNEL);
+ if (!channel->bounce_buffer)
+ return -ENOMEM;
+
+ channel->cb = qsdrv->callback;
+
+ qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENING);
+
+ qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENED);
+
+ ret = qsdrv->probe(qsdev);
+ if (ret)
+ goto err;
+
+ qcom_smd_channel_resume(channel);
+
+ return 0;
+
+err:
+ dev_err(&qsdev->dev, "probe failed\n");
+
+ channel->cb = NULL;
+ kfree(channel->bounce_buffer);
+ channel->bounce_buffer = NULL;
+
+ qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED);
+ return ret;
+}
+
+/*
+ * Remove the smd client.
+ *
+ * The channel is going away, for some reason, so remove the smd client and
+ * reset the channel state.
+ */
+static int qcom_smd_dev_remove(struct device *dev)
+{
+ struct qcom_smd_device *qsdev = to_smd_device(dev);
+ struct qcom_smd_driver *qsdrv = to_smd_driver(dev);
+ struct qcom_smd_channel *channel = qsdev->channel;
+ unsigned long flags;
+
+ qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSING);
+
+ /*
+ * Make sure we don't race with the code receiving data.
+ */
+ spin_lock_irqsave(&channel->recv_lock, flags);
+ channel->cb = NULL;
+ spin_unlock_irqrestore(&channel->recv_lock, flags);
+
+ /* Wake up any sleepers in qcom_smd_send() */
+ wake_up_interruptible(&channel->fblockread_event);
+
+ /*
+ * We expect that the client might block in remove() waiting for any
+ * outstanding calls to qcom_smd_send() to wake up and finish.
+ */
+ if (qsdrv->remove)
+ qsdrv->remove(qsdev);
+
+ /*
+ * The client is now gone, cleanup and reset the channel state.
+ */
+ channel->qsdev = NULL;
+ kfree(channel->bounce_buffer);
+ channel->bounce_buffer = NULL;
+
+ qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED);
+
+ qcom_smd_channel_reset(channel);
+
+ return 0;
+}
+
+static struct bus_type qcom_smd_bus = {
+ .name = "qcom_smd",
+ .match = qcom_smd_dev_match,
+ .probe = qcom_smd_dev_probe,
+ .remove = qcom_smd_dev_remove,
+};
+
+/*
+ * Release function for the qcom_smd_device object.
+ */
+static void qcom_smd_release_device(struct device *dev)
+{
+ struct qcom_smd_device *qsdev = to_smd_device(dev);
+
+ kfree(qsdev);
+}
+
+/*
+ * 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) {
+ of_node_put(child);
+ continue;
+ }
+
+ if (strcmp(name, channel) == 0)
+ return child;
+ }
+
+ return NULL;
+}
+
+/*
+ * 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 qcom_smd_edge *edge = channel->edge;
+ struct device_node *node;
+ struct qcom_smd *smd = edge->smd;
+ int ret;
+
+ if (channel->qsdev)
+ return -EEXIST;
+
+ node = qcom_smd_match_channel(edge->of_node, channel->name);
+ if (!node) {
+ dev_dbg(smd->dev, "no match for '%s'\n", channel->name);
+ return -ENXIO;
+ }
+
+ dev_dbg(smd->dev, "registering '%s'\n", channel->name);
+
+ qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL);
+ if (!qsdev)
+ return -ENOMEM;
+
+ dev_set_name(&qsdev->dev, "%s.%s", edge->of_node->name, node->name);
+ qsdev->dev.parent = smd->dev;
+ qsdev->dev.bus = &qcom_smd_bus;
+ qsdev->dev.release = qcom_smd_release_device;
+ qsdev->dev.of_node = node;
+
+ qsdev->channel = channel;
+
+ channel->qsdev = qsdev;
+
+ ret = device_register(&qsdev->dev);
+ if (ret) {
+ dev_err(smd->dev, "device_register failed: %d\n", ret);
+ put_device(&qsdev->dev);
+ }
+
+ return ret;
+}
+
+/*
+ * Destroy a smd client device for a channel that's going away.
+ */
+static void qcom_smd_destroy_device(struct qcom_smd_channel *channel)
+{
+ struct device *dev;
+
+ BUG_ON(!channel->qsdev);
+
+ dev = &channel->qsdev->dev;
+
+ device_unregister(dev);
+ of_node_put(dev->of_node);
+ put_device(dev);
+}
+
+/**
+ * qcom_smd_driver_register - register a smd driver
+ * @qsdrv: qcom_smd_driver struct
+ */
+int qcom_smd_driver_register(struct qcom_smd_driver *qsdrv)
+{
+ qsdrv->driver.bus = &qcom_smd_bus;
+ return driver_register(&qsdrv->driver);
+}
+EXPORT_SYMBOL(qcom_smd_driver_register);
+
+/**
+ * qcom_smd_driver_unregister - unregister a smd driver
+ * @qsdrv: qcom_smd_driver struct
+ */
+void qcom_smd_driver_unregister(struct qcom_smd_driver *qsdrv)
+{
+ driver_unregister(&qsdrv->driver);
+}
+EXPORT_SYMBOL(qcom_smd_driver_unregister);
+
+/*
+ * 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;
+ struct qcom_smd *smd = edge->smd;
+ size_t fifo_size;
+ size_t info_size;
+ void *fifo_base;
+ void *info;
+ int ret;
+
+ channel = devm_kzalloc(smd->dev, sizeof(*channel), GFP_KERNEL);
+ if (!channel)
+ return ERR_PTR(-ENOMEM);
+
+ channel->edge = edge;
+ channel->name = devm_kstrdup(smd->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);
+
+ ret = qcom_smem_get(edge->edge_id, smem_info_item, (void **)&info, &info_size);
+ if (ret)
+ 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->tx_info_word = info;
+ channel->rx_info_word = info + sizeof(struct smd_channel_info_word);
+ } else if (info_size == 2 * sizeof(struct smd_channel_info)) {
+ channel->tx_info = info;
+ channel->rx_info = info + sizeof(struct smd_channel_info);
+ } else {
+ dev_err(smd->dev,
+ "channel info of size %d not supported\n", info_size);
+ ret = -EINVAL;
+ goto free_name_and_channel;
+ }
+
+ ret = qcom_smem_get(edge->edge_id, smem_fifo_item, &fifo_base, &fifo_size);
+ if (ret)
+ goto free_name_and_channel;
+
+ /* The channel consist of a rx and tx fifo of equal size */
+ fifo_size /= 2;
+
+ dev_dbg(smd->dev, "new channel '%s' info-size: %d fifo-size: %d\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(smd->dev, channel->name);
+ devm_kfree(smd->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_discover_channels(struct qcom_smd_edge *edge)
+{
+ struct qcom_smd_alloc_entry *entry;
+ struct qcom_smd_channel *channel;
+ struct qcom_smd *smd = edge->smd;
+ unsigned long flags;
+ unsigned fifo_id;
+ unsigned info_id;
+ int tbl;
+ int i;
+
+ for (i = 0; i < smd->alloc_tbl_entries; i++) {
+ tbl = i / SMD_ALLOC_TBL_SIZE;
+
+ entry = &smd->alloc_tbl[tbl][i];
+ if (test_bit(i, smd->allocated))
+ continue;
+
+ if (entry->ref_count == 0)
+ continue;
+
+ if (!entry->name[0])
+ continue;
+
+ if (!(entry->flags & SMD_CHANNEL_FLAGS_PACKET))
+ continue;
+
+ if ((entry->flags & SMD_CHANNEL_FLAGS_EDGE_MASK) != edge->edge_id)
+ continue;
+
+ info_id = smem_items[tbl].info_base_id + entry->cid;
+ fifo_id = smem_items[tbl].fifo_base_id + entry->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(smd->dev, "new channel found: '%s'\n", channel->name);
+ set_bit(i, smd->allocated);
+ }
+
+ schedule_work(&edge->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 is not needed to be held during the traversal
+ * of the channels list as it's done synchronously with the only writer.
+ */
+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,
+ work);
+ unsigned remote_state;
+
+ /*
+ * Rescan smem if we have reason to belive that there are new channels.
+ */
+ if (edge->need_rescan) {
+ edge->need_rescan = false;
+ qcom_discover_channels(edge);
+ }
+
+ /*
+ * Register a device for any closed channel where the remote processor
+ * is showing interest in opening the channel.
+ */
+ 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;
+
+ qcom_smd_create_device(channel);
+ }
+
+ /*
+ * 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;
+
+ qcom_smd_destroy_device(channel);
+ }
+}
+
+/*
+ * 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->work, qcom_channel_state_worker);
+
+ edge->of_node = of_node_get(node);
+
+ 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;
+
+ 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;
+ }
+
+ 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;
+ }
+
+ return 0;
+}
+
+static int qcom_smd_probe(struct platform_device *pdev)
+{
+ struct qcom_smd_edge *edge;
+ struct device_node *node;
+ struct qcom_smd *smd;
+ size_t array_size;
+ int num_edges;
+ int ret;
+ int i = 0;
+
+ num_edges = of_get_available_child_count(pdev->dev.of_node);
+ array_size = sizeof(*smd) + num_edges * sizeof(struct qcom_smd_edge);
+ smd = devm_kzalloc(&pdev->dev, array_size, GFP_KERNEL);
+ if (!smd)
+ return -ENOMEM;
+ smd->dev = &pdev->dev;
+
+ ret = qcom_smem_get(QCOM_SMEM_HOST_ANY, smem_items[0].alloc_tbl_id,
+ (void **)&smd->alloc_tbl[0], NULL);
+ if (ret < 0) {
+ dev_err(smd->dev, "primary allocation table not available\n");
+ return ret;
+ };
+
+ smd->alloc_tbl_entries = SMD_ALLOC_TBL_SIZE;
+
+ ret = qcom_smem_get(QCOM_SMEM_HOST_ANY, smem_items[1].alloc_tbl_id,
+ (void **)&smd->alloc_tbl[1], NULL);
+ if (ret >= 0)
+ smd->alloc_tbl_entries += SMD_ALLOC_TBL_SIZE;
+
+ smd->num_edges = num_edges;
+ for_each_available_child_of_node(pdev->dev.of_node, node) {
+ edge = &smd->edges[i++];
+ edge->smd = smd;
+
+ ret = qcom_smd_parse_edge(&pdev->dev, node, edge);
+ if (ret)
+ continue;
+
+ edge->need_rescan = true;
+ schedule_work(&edge->work);
+ }
+
+ platform_set_drvdata(pdev, smd);
+
+ return 0;
+}
+
+/*
+ * 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)
+{
+ struct qcom_smd_channel *channel;
+ struct qcom_smd_edge *edge;
+ struct qcom_smd *smd = platform_get_drvdata(pdev);
+ int i;
+
+ for (i = 0; i < smd->num_edges; i++) {
+ edge = &smd->edges[i];
+
+ disable_irq(edge->irq);
+ cancel_work_sync(&edge->work);
+
+ list_for_each_entry(channel, &edge->channels, list) {
+ if (!channel->qsdev)
+ continue;
+
+ qcom_smd_destroy_device(channel);
+ }
+ }
+
+ return 0;
+}
+
+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",
+ .owner = THIS_MODULE,
+ .of_match_table = qcom_smd_of_match,
+ },
+};
+
+static int __init qcom_smd_init(void)
+{
+ int ret;
+
+ ret = bus_register(&qcom_smd_bus);
+ if (ret) {
+ pr_err("failed to register smd bus: %d\n", ret);
+ return ret;
+ }
+
+ return platform_driver_register(&qcom_smd_driver);
+}
+arch_initcall(qcom_smd_init);
+
+static void __exit qcom_smd_exit(void)
+{
+ platform_driver_unregister(&qcom_smd_driver);
+ bus_unregister(&qcom_smd_bus);
+}
+module_exit(qcom_smd_exit);
+
+MODULE_AUTHOR("Bjorn Andersson <[email protected]>");
+MODULE_DESCRIPTION("Qualcomm Shared Memory Driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/soc/qcom/smd.h b/include/linux/soc/qcom/smd.h
new file mode 100644
index 0000000..581ec24
--- /dev/null
+++ b/include/linux/soc/qcom/smd.h
@@ -0,0 +1,47 @@
+#ifndef __LINUX_MSM_SMEM_H__
+#define __LINUX_MSM_SMEM_H__
+
+#include <linux/device.h>
+#include <linux/mod_devicetable.h>
+
+struct qcom_smd;
+struct qcom_smd_channel;
+struct qcom_smd_lookup;
+
+/**
+ * struct qcom_smd_device - smd device struct
+ * @dev: the device struct
+ * @channel: handle to the smd channel for this device
+ */
+struct qcom_smd_device {
+ struct device dev;
+ struct qcom_smd_channel *channel;
+};
+
+/**
+ * struct qcom_smd_driver - smd driver struct
+ * @driver: underlying device driver
+ * @probe: invoked when the smd channel is found
+ * @remove: invoked when the smd channel is closed
+ * @callback: invoked when an inbound message is received on the channel,
+ * should return 0 on success or -EBUSY if the data cannot be
+ * consumed at this time
+ */
+struct qcom_smd_driver {
+ struct device_driver driver;
+ int (*probe)(struct qcom_smd_device *dev);
+ void (*remove)(struct qcom_smd_device *dev);
+ int (*callback)(struct qcom_smd_device *, const void *, size_t);
+};
+
+int qcom_smd_driver_register(struct qcom_smd_driver *drv);
+void qcom_smd_driver_unregister(struct qcom_smd_driver *drv);
+
+#define module_qcom_smd_driver(__smd_driver) \
+ module_driver(__smd_driver, qcom_smd_driver_register, \
+ qcom_smd_driver_unregister)
+
+int qcom_smd_send(struct qcom_smd_channel *channel, const void *data, int len);
+
+#endif
+
--
1.8.2.2
Corrected spelling of the msm mailing list...
On Fri 10 Apr 17:16 PDT 2015, Bjorn Andersson wrote:
> Add device tree binding documentation for the Qualcomm Shared Memory
> Device, used for communication between the various CPUs in the Qualcomm
> SoCs.
>
> Signed-off-by: Bjorn Andersson <[email protected]>
> ---
> .../devicetree/bindings/soc/qcom/qcom,smd.txt | 78 ++++++++++++++++++++++
> 1 file changed, 78 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/soc/qcom/qcom,smd.txt
>
> diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,smd.txt b/Documentation/devicetree/bindings/soc/qcom/qcom,smd.txt
> new file mode 100644
> index 0000000..0fdb7f9d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/soc/qcom/qcom,smd.txt
> @@ -0,0 +1,78 @@
> +Qualcomm Shared Memory Driver (SMD) binding
> +
> +This binding describes the Qualcomm Shared Memory Driver, a fifo based
> +communication channel for sending data between the various subsystems in
> +Qualcomm platforms.
> +
> +- compatible:
> + Usage: required
> + Value type: <stringlist>
> + Definition: must be "qcom,smd"
> +
> += EDGES
> +
> +Each subnode of the SMD node represents a remote subsystem or a remote
> +processor of some sort - or in SMD language an "edge". The name of the
> +edges are not important.
> +
> +- interrupts:
> + Usage: required
> + Value type: <prop-encoded-array>
> + Definition: should specify the IRQ used by the remote processor to
> + signal this processor about communication related updates
> +
> +- qcom,ipc:
> + Usage: required
> + Value type: <prop-encoded-array>
> + Definition: three entries specifying the outgoing ipc bit used for
> + signaling the remote processor:
> + - phandle to a syscon node representing the apcs registers
> + - u32 representing offset to the register within the syscon
> + - u32 representing the ipc bit within the register
> +
> +- qcom,smd-edge:
> + Usage: required
> + Value type: <u32>
> + Definition: the identifier representing the remote processor in the
> + smd channel allocation table
> +
> += SMD DEVICES
> +
> +In turn, subnodes of the "edges" represent devices tied to SMD channels on that
> +"edge". The names of the devices are not important. The properties of these
> +nodes are defined by the individual bindings for the SMD devices - but must
> +contain the following property:
> +
> +- qcom,smd-channels:
> + Usage: required
> + Value type: <stringlist>
> + Definition: a list of channels tied to this device, used for matching
> + the device to channels
> +
> += EXAMPLE
> +
> +The following example represents a smd node, with one edge representing the
> +"rpm" subsystem. For the "rpm" subsystem we have a device tied to the
> +"rpm_request" channel.
> +
> + apcs: syscon@f9011000 {
> + compatible = "syscon";
> + reg = <0xf9011000 0x1000>;
> + };
> +
> + smd {
> + compatible = "qcom,smd";
> +
> + rpm {
> + interrupts = <0 168 1>;
> + qcom,ipc = <&apcs 8 0>;
> + qcom,smd-edge = <15>;
> +
> + rpm_requests {
> + compatible = "qcom,rpm-msm8974";
> + qcom,smd-channels = "rpm_requests";
> +
> + ...
> + };
> + };
> + };
> --
> 1.8.2.2
>