diff options
author | Bjorn Andersson <bjorn.andersson@linaro.org> | 2017-05-28 01:23:35 +0200 |
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committer | Bjorn Andersson <bjorn.andersson@linaro.org> | 2017-05-31 05:57:23 +0200 |
commit | b4f8e52b89f69f5563ac4cb9ffdacc4418917af1 (patch) | |
tree | fb7803e613c371fabfcc164bfc2c32a8e2955bc3 /drivers/rpmsg/qcom_glink_rpm.c | |
parent | soc: qcom: Add device tree binding for GLINK RPM (diff) | |
download | linux-b4f8e52b89f69f5563ac4cb9ffdacc4418917af1.tar.xz linux-b4f8e52b89f69f5563ac4cb9ffdacc4418917af1.zip |
rpmsg: Introduce Qualcomm RPM glink driver
This introduces a basic driver for communicating over "native glink"
with the RPM found in Qualcomm platforms.
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Diffstat (limited to 'drivers/rpmsg/qcom_glink_rpm.c')
-rw-r--r-- | drivers/rpmsg/qcom_glink_rpm.c | 1233 |
1 files changed, 1233 insertions, 0 deletions
diff --git a/drivers/rpmsg/qcom_glink_rpm.c b/drivers/rpmsg/qcom_glink_rpm.c new file mode 100644 index 000000000000..3559a3e84c1e --- /dev/null +++ b/drivers/rpmsg/qcom_glink_rpm.c @@ -0,0 +1,1233 @@ +/* + * Copyright (c) 2016-2017, Linaro Ltd + * + * 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/idr.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/list.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/rpmsg.h> +#include <linux/slab.h> +#include <linux/workqueue.h> +#include <linux/mailbox_client.h> + +#include "rpmsg_internal.h" + +#define RPM_TOC_SIZE 256 +#define RPM_TOC_MAGIC 0x67727430 /* grt0 */ +#define RPM_TOC_MAX_ENTRIES ((RPM_TOC_SIZE - sizeof(struct rpm_toc)) / \ + sizeof(struct rpm_toc_entry)) + +#define RPM_TX_FIFO_ID 0x61703272 /* ap2r */ +#define RPM_RX_FIFO_ID 0x72326170 /* r2ap */ + +#define GLINK_NAME_SIZE 32 + +#define RPM_GLINK_CID_MIN 1 +#define RPM_GLINK_CID_MAX 65536 + +struct rpm_toc_entry { + __le32 id; + __le32 offset; + __le32 size; +} __packed; + +struct rpm_toc { + __le32 magic; + __le32 count; + + struct rpm_toc_entry entries[]; +} __packed; + +struct glink_msg { + __le16 cmd; + __le16 param1; + __le32 param2; + u8 data[]; +} __packed; + +struct glink_rpm_pipe { + void __iomem *tail; + void __iomem *head; + + void __iomem *fifo; + + size_t length; +}; + +/** + * struct glink_defer_cmd - deferred incoming control message + * @node: list node + * @msg: message header + * data: payload of the message + * + * Copy of a received control message, to be added to @rx_queue and processed + * by @rx_work of @glink_rpm. + */ +struct glink_defer_cmd { + struct list_head node; + + struct glink_msg msg; + u8 data[]; +}; + +/** + * struct glink_rpm - driver context, relates to one remote subsystem + * @dev: reference to the associated struct device + * @doorbell: "rpm_hlos" ipc doorbell + * @rx_pipe: pipe object for receive FIFO + * @tx_pipe: pipe object for transmit FIFO + * @irq: IRQ for signaling incoming events + * @rx_work: worker for handling received control messages + * @rx_lock: protects the @rx_queue + * @rx_queue: queue of received control messages to be processed in @rx_work + * @tx_lock: synchronizes operations on the tx fifo + * @idr_lock: synchronizes @lcids and @rcids modifications + * @lcids: idr of all channels with a known local channel id + * @rcids: idr of all channels with a known remote channel id + */ +struct glink_rpm { + struct device *dev; + + struct mbox_client mbox_client; + struct mbox_chan *mbox_chan; + + struct glink_rpm_pipe rx_pipe; + struct glink_rpm_pipe tx_pipe; + + int irq; + + struct work_struct rx_work; + spinlock_t rx_lock; + struct list_head rx_queue; + + struct mutex tx_lock; + + struct mutex idr_lock; + struct idr lcids; + struct idr rcids; +}; + +enum { + GLINK_STATE_CLOSED, + GLINK_STATE_OPENING, + GLINK_STATE_OPEN, + GLINK_STATE_CLOSING, +}; + +/** + * struct glink_channel - internal representation of a channel + * @rpdev: rpdev reference, only used for primary endpoints + * @ept: rpmsg endpoint this channel is associated with + * @glink: glink_rpm context handle + * @refcount: refcount for the channel object + * @recv_lock: guard for @ept.cb + * @name: unique channel name/identifier + * @lcid: channel id, in local space + * @rcid: channel id, in remote space + * @buf: receive buffer, for gathering fragments + * @buf_offset: write offset in @buf + * @buf_size: size of current @buf + * @open_ack: completed once remote has acked the open-request + * @open_req: completed once open-request has been received + */ +struct glink_channel { + struct rpmsg_endpoint ept; + + struct rpmsg_device *rpdev; + struct glink_rpm *glink; + + struct kref refcount; + + spinlock_t recv_lock; + + char *name; + unsigned int lcid; + unsigned int rcid; + + void *buf; + int buf_offset; + int buf_size; + + struct completion open_ack; + struct completion open_req; +}; + +#define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept) + +static const struct rpmsg_endpoint_ops glink_endpoint_ops; + +#define RPM_CMD_VERSION 0 +#define RPM_CMD_VERSION_ACK 1 +#define RPM_CMD_OPEN 2 +#define RPM_CMD_CLOSE 3 +#define RPM_CMD_OPEN_ACK 4 +#define RPM_CMD_TX_DATA 9 +#define RPM_CMD_CLOSE_ACK 11 +#define RPM_CMD_TX_DATA_CONT 12 +#define RPM_CMD_READ_NOTIF 13 + +#define GLINK_FEATURE_INTENTLESS BIT(1) + +static struct glink_channel *glink_rpm_alloc_channel(struct glink_rpm *glink, + const char *name) +{ + struct glink_channel *channel; + + channel = kzalloc(sizeof(*channel), GFP_KERNEL); + if (!channel) + return ERR_PTR(-ENOMEM); + + /* Setup glink internal glink_channel data */ + spin_lock_init(&channel->recv_lock); + channel->glink = glink; + channel->name = kstrdup(name, GFP_KERNEL); + + init_completion(&channel->open_req); + init_completion(&channel->open_ack); + + kref_init(&channel->refcount); + + return channel; +} + +static void glink_rpm_channel_release(struct kref *ref) +{ + struct glink_channel *channel = container_of(ref, struct glink_channel, + refcount); + + kfree(channel->name); + kfree(channel); +} + +static size_t glink_rpm_rx_avail(struct glink_rpm *glink) +{ + struct glink_rpm_pipe *pipe = &glink->rx_pipe; + unsigned int head; + unsigned int tail; + + head = readl(pipe->head); + tail = readl(pipe->tail); + + if (head < tail) + return pipe->length - tail + head; + else + return head - tail; +} + +static void glink_rpm_rx_peak(struct glink_rpm *glink, + void *data, size_t count) +{ + struct glink_rpm_pipe *pipe = &glink->rx_pipe; + unsigned int tail; + size_t len; + + tail = readl(pipe->tail); + + len = min_t(size_t, count, pipe->length - tail); + if (len) { + __ioread32_copy(data, pipe->fifo + tail, + len / sizeof(u32)); + } + + if (len != count) { + __ioread32_copy(data + len, pipe->fifo, + (count - len) / sizeof(u32)); + } +} + +static void glink_rpm_rx_advance(struct glink_rpm *glink, + size_t count) +{ + struct glink_rpm_pipe *pipe = &glink->rx_pipe; + unsigned int tail; + + tail = readl(pipe->tail); + + tail += count; + if (tail >= pipe->length) + tail -= pipe->length; + + writel(tail, pipe->tail); +} + +static size_t glink_rpm_tx_avail(struct glink_rpm *glink) +{ + struct glink_rpm_pipe *pipe = &glink->tx_pipe; + unsigned int head; + unsigned int tail; + + head = readl(pipe->head); + tail = readl(pipe->tail); + + if (tail <= head) + return pipe->length - head + tail; + else + return tail - head; +} + +static unsigned int glink_rpm_tx_write(struct glink_rpm *glink, + unsigned int head, + const void *data, size_t count) +{ + struct glink_rpm_pipe *pipe = &glink->tx_pipe; + size_t len; + + len = min_t(size_t, count, pipe->length - head); + if (len) { + __iowrite32_copy(pipe->fifo + head, data, + len / sizeof(u32)); + } + + if (len != count) { + __iowrite32_copy(pipe->fifo, data + len, + (count - len) / sizeof(u32)); + } + + head += count; + if (head >= pipe->length) + head -= pipe->length; + + return head; +} + +static int glink_rpm_tx(struct glink_rpm *glink, + const void *hdr, size_t hlen, + const void *data, size_t dlen, bool wait) +{ + struct glink_rpm_pipe *pipe = &glink->tx_pipe; + unsigned int head; + unsigned int tlen = hlen + dlen; + int ret; + + /* Reject packets that are too big */ + if (tlen >= glink->tx_pipe.length) + return -EINVAL; + + if (WARN(tlen % 8, "Unaligned TX request")) + return -EINVAL; + + ret = mutex_lock_interruptible(&glink->tx_lock); + if (ret) + return ret; + + while (glink_rpm_tx_avail(glink) < tlen) { + if (!wait) { + ret = -ENOMEM; + goto out; + } + + msleep(10); + } + + head = readl(pipe->head); + head = glink_rpm_tx_write(glink, head, hdr, hlen); + head = glink_rpm_tx_write(glink, head, data, dlen); + writel(head, pipe->head); + + mbox_send_message(glink->mbox_chan, NULL); + mbox_client_txdone(glink->mbox_chan, 0); + +out: + mutex_unlock(&glink->tx_lock); + + return ret; +} + +static int glink_rpm_send_version(struct glink_rpm *glink) +{ + struct glink_msg msg; + + msg.cmd = cpu_to_le16(RPM_CMD_VERSION); + msg.param1 = cpu_to_le16(1); + msg.param2 = cpu_to_le32(GLINK_FEATURE_INTENTLESS); + + return glink_rpm_tx(glink, &msg, sizeof(msg), NULL, 0, true); +} + +static void glink_rpm_send_version_ack(struct glink_rpm *glink) +{ + struct glink_msg msg; + + msg.cmd = cpu_to_le16(RPM_CMD_VERSION_ACK); + msg.param1 = cpu_to_le16(1); + msg.param2 = cpu_to_le32(0); + + glink_rpm_tx(glink, &msg, sizeof(msg), NULL, 0, true); +} + +static void glink_rpm_send_open_ack(struct glink_rpm *glink, + struct glink_channel *channel) +{ + struct glink_msg msg; + + msg.cmd = cpu_to_le16(RPM_CMD_OPEN_ACK); + msg.param1 = cpu_to_le16(channel->rcid); + msg.param2 = cpu_to_le32(0); + + glink_rpm_tx(glink, &msg, sizeof(msg), NULL, 0, true); +} + +/** + * glink_rpm_send_open_req() - send a RPM_CMD_OPEN request to the remote + * @glink: + * @channel: + * + * Allocates a local channel id and sends a RPM_CMD_OPEN message to the remote. + * Will return with refcount held, regardless of outcome. + * + * Returns 0 on success, negative errno otherwise. + */ +static int glink_rpm_send_open_req(struct glink_rpm *glink, + struct glink_channel *channel) +{ + struct { + struct glink_msg msg; + u8 name[GLINK_NAME_SIZE]; + } __packed req; + int name_len = strlen(channel->name) + 1; + int req_len = ALIGN(sizeof(req.msg) + name_len, 8); + int ret; + + kref_get(&channel->refcount); + + mutex_lock(&glink->idr_lock); + ret = idr_alloc_cyclic(&glink->lcids, channel, + RPM_GLINK_CID_MIN, RPM_GLINK_CID_MAX, GFP_KERNEL); + mutex_unlock(&glink->idr_lock); + if (ret < 0) + return ret; + + channel->lcid = ret; + + req.msg.cmd = cpu_to_le16(RPM_CMD_OPEN); + req.msg.param1 = cpu_to_le16(channel->lcid); + req.msg.param2 = cpu_to_le32(name_len); + strcpy(req.name, channel->name); + + ret = glink_rpm_tx(glink, &req, req_len, NULL, 0, true); + if (ret) + goto remove_idr; + + return 0; + +remove_idr: + mutex_lock(&glink->idr_lock); + idr_remove(&glink->lcids, channel->lcid); + channel->lcid = 0; + mutex_unlock(&glink->idr_lock); + + return ret; +} + +static void glink_rpm_send_close_req(struct glink_rpm *glink, + struct glink_channel *channel) +{ + struct glink_msg req; + + req.cmd = cpu_to_le16(RPM_CMD_CLOSE); + req.param1 = cpu_to_le16(channel->lcid); + req.param2 = 0; + + glink_rpm_tx(glink, &req, sizeof(req), NULL, 0, true); +} + +static void glink_rpm_send_close_ack(struct glink_rpm *glink, unsigned int rcid) +{ + struct glink_msg req; + + req.cmd = cpu_to_le16(RPM_CMD_CLOSE_ACK); + req.param1 = cpu_to_le16(rcid); + req.param2 = 0; + + glink_rpm_tx(glink, &req, sizeof(req), NULL, 0, true); +} + +static int glink_rpm_rx_defer(struct glink_rpm *glink, size_t extra) +{ + struct glink_defer_cmd *dcmd; + + extra = ALIGN(extra, 8); + + if (glink_rpm_rx_avail(glink) < sizeof(struct glink_msg) + extra) { + dev_dbg(glink->dev, "Insufficient data in rx fifo"); + return -ENXIO; + } + + dcmd = kzalloc(sizeof(*dcmd) + extra, GFP_ATOMIC); + if (!dcmd) + return -ENOMEM; + + INIT_LIST_HEAD(&dcmd->node); + + glink_rpm_rx_peak(glink, &dcmd->msg, sizeof(dcmd->msg) + extra); + + spin_lock(&glink->rx_lock); + list_add_tail(&dcmd->node, &glink->rx_queue); + spin_unlock(&glink->rx_lock); + + schedule_work(&glink->rx_work); + glink_rpm_rx_advance(glink, sizeof(dcmd->msg) + extra); + + return 0; +} + +static int glink_rpm_rx_data(struct glink_rpm *glink, size_t avail) +{ + struct glink_channel *channel; + struct { + struct glink_msg msg; + __le32 chunk_size; + __le32 left_size; + } __packed hdr; + unsigned int chunk_size; + unsigned int left_size; + unsigned int rcid; + + if (avail < sizeof(hdr)) { + dev_dbg(glink->dev, "Not enough data in fifo\n"); + return -EAGAIN; + } + + glink_rpm_rx_peak(glink, &hdr, sizeof(hdr)); + chunk_size = le32_to_cpu(hdr.chunk_size); + left_size = le32_to_cpu(hdr.left_size); + + if (avail < sizeof(hdr) + chunk_size) { + dev_dbg(glink->dev, "Payload not yet in fifo\n"); + return -EAGAIN; + } + + if (WARN(chunk_size % 4, "Incoming data must be word aligned\n")) + return -EINVAL; + + rcid = le16_to_cpu(hdr.msg.param1); + channel = idr_find(&glink->rcids, rcid); + if (!channel) { + dev_dbg(glink->dev, "Data on non-existing channel\n"); + + /* Drop the message */ + glink_rpm_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8)); + return 0; + } + + /* Might have an ongoing, fragmented, message to append */ + if (!channel->buf) { + channel->buf = kmalloc(chunk_size + left_size, GFP_ATOMIC); + if (!channel->buf) + return -ENOMEM; + + channel->buf_size = chunk_size + left_size; + channel->buf_offset = 0; + } + + glink_rpm_rx_advance(glink, sizeof(hdr)); + + if (channel->buf_size - channel->buf_offset < chunk_size) { + dev_err(glink->dev, "Insufficient space in input buffer\n"); + + /* The packet header lied, drop payload */ + glink_rpm_rx_advance(glink, chunk_size); + return -ENOMEM; + } + + glink_rpm_rx_peak(glink, channel->buf + channel->buf_offset, chunk_size); + channel->buf_offset += chunk_size; + + /* Handle message when no fragments remain to be received */ + if (!left_size) { + spin_lock(&channel->recv_lock); + if (channel->ept.cb) { + channel->ept.cb(channel->ept.rpdev, + channel->buf, + channel->buf_offset, + channel->ept.priv, + RPMSG_ADDR_ANY); + } + spin_unlock(&channel->recv_lock); + + kfree(channel->buf); + channel->buf = NULL; + channel->buf_size = 0; + } + + /* Each message starts at 8 byte aligned address */ + glink_rpm_rx_advance(glink, ALIGN(chunk_size, 8)); + + return 0; +} + +static int glink_rpm_rx_open_ack(struct glink_rpm *glink, unsigned int lcid) +{ + struct glink_channel *channel; + + channel = idr_find(&glink->lcids, lcid); + if (!channel) { + dev_err(glink->dev, "Invalid open ack packet\n"); + return -EINVAL; + } + + complete(&channel->open_ack); + + return 0; +} + +static irqreturn_t glink_rpm_intr(int irq, void *data) +{ + struct glink_rpm *glink = data; + struct glink_msg msg; + unsigned int param1; + unsigned int param2; + unsigned int avail; + unsigned int cmd; + int ret; + + for (;;) { + avail = glink_rpm_rx_avail(glink); + if (avail < sizeof(msg)) + break; + + glink_rpm_rx_peak(glink, &msg, sizeof(msg)); + + cmd = le16_to_cpu(msg.cmd); + param1 = le16_to_cpu(msg.param1); + param2 = le32_to_cpu(msg.param2); + + switch (cmd) { + case RPM_CMD_VERSION: + case RPM_CMD_VERSION_ACK: + case RPM_CMD_CLOSE: + case RPM_CMD_CLOSE_ACK: + ret = glink_rpm_rx_defer(glink, 0); + break; + case RPM_CMD_OPEN_ACK: + ret = glink_rpm_rx_open_ack(glink, param1); + glink_rpm_rx_advance(glink, ALIGN(sizeof(msg), 8)); + break; + case RPM_CMD_OPEN: + ret = glink_rpm_rx_defer(glink, param2); + break; + case RPM_CMD_TX_DATA: + case RPM_CMD_TX_DATA_CONT: + ret = glink_rpm_rx_data(glink, avail); + break; + case RPM_CMD_READ_NOTIF: + glink_rpm_rx_advance(glink, ALIGN(sizeof(msg), 8)); + + mbox_send_message(glink->mbox_chan, NULL); + mbox_client_txdone(glink->mbox_chan, 0); + + ret = 0; + break; + default: + dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd); + ret = -EINVAL; + break; + } + + if (ret) + break; + } + + return IRQ_HANDLED; +} + +/* Locally initiated rpmsg_create_ept */ +static struct glink_channel *glink_rpm_create_local(struct glink_rpm *glink, + const char *name) +{ + struct glink_channel *channel; + int ret; + + channel = glink_rpm_alloc_channel(glink, name); + if (IS_ERR(channel)) + return ERR_CAST(channel); + + ret = glink_rpm_send_open_req(glink, channel); + if (ret) + goto release_channel; + + ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ); + if (!ret) + goto err_timeout; + + ret = wait_for_completion_timeout(&channel->open_req, 5 * HZ); + if (!ret) + goto err_timeout; + + glink_rpm_send_open_ack(glink, channel); + + return channel; + +err_timeout: + /* glink_rpm_send_open_req() did register the channel in lcids*/ + mutex_lock(&glink->idr_lock); + idr_remove(&glink->lcids, channel->lcid); + mutex_unlock(&glink->idr_lock); + +release_channel: + /* Release glink_rpm_send_open_req() reference */ + kref_put(&channel->refcount, glink_rpm_channel_release); + /* Release glink_rpm_alloc_channel() reference */ + kref_put(&channel->refcount, glink_rpm_channel_release); + + return ERR_PTR(-ETIMEDOUT); +} + +/* Remote initiated rpmsg_create_ept */ +static int glink_rpm_create_remote(struct glink_rpm *glink, + struct glink_channel *channel) +{ + int ret; + + glink_rpm_send_open_ack(glink, channel); + + ret = glink_rpm_send_open_req(glink, channel); + if (ret) + goto close_link; + + ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ); + if (!ret) { + ret = -ETIMEDOUT; + goto close_link; + } + + return 0; + +close_link: + /* + * Send a close request to "undo" our open-ack. The close-ack will + * release the last reference. + */ + glink_rpm_send_close_req(glink, channel); + + /* Release glink_rpm_send_open_req() reference */ + kref_put(&channel->refcount, glink_rpm_channel_release); + + return ret; +} + +static struct rpmsg_endpoint *glink_rpm_create_ept(struct rpmsg_device *rpdev, + rpmsg_rx_cb_t cb, void *priv, + struct rpmsg_channel_info chinfo) +{ + struct glink_channel *parent = to_glink_channel(rpdev->ept); + struct glink_channel *channel; + struct glink_rpm *glink = parent->glink; + struct rpmsg_endpoint *ept; + const char *name = chinfo.name; + int cid; + int ret; + + idr_for_each_entry(&glink->rcids, channel, cid) { + if (!strcmp(channel->name, name)) + break; + } + + if (!channel) { + channel = glink_rpm_create_local(glink, name); + if (IS_ERR(channel)) + return NULL; + } else { + ret = glink_rpm_create_remote(glink, channel); + if (ret) + return NULL; + } + + ept = &channel->ept; + ept->rpdev = rpdev; + ept->cb = cb; + ept->priv = priv; + ept->ops = &glink_endpoint_ops; + + return ept; +} + +static void glink_rpm_destroy_ept(struct rpmsg_endpoint *ept) +{ + struct glink_channel *channel = to_glink_channel(ept); + struct glink_rpm *glink = channel->glink; + unsigned long flags; + + spin_lock_irqsave(&channel->recv_lock, flags); + channel->ept.cb = NULL; + spin_unlock_irqrestore(&channel->recv_lock, flags); + + /* Decouple the potential rpdev from the channel */ + channel->rpdev = NULL; + + glink_rpm_send_close_req(glink, channel); +} + +static int __glink_rpm_send(struct glink_channel *channel, + void *data, int len, bool wait) +{ + struct glink_rpm *glink = channel->glink; + struct { + struct glink_msg msg; + __le32 chunk_size; + __le32 left_size; + } __packed req; + + if (WARN(len % 8, "RPM GLINK expects 8 byte aligned messages\n")) + return -EINVAL; + + req.msg.cmd = cpu_to_le16(RPM_CMD_TX_DATA); + req.msg.param1 = cpu_to_le16(channel->lcid); + req.msg.param2 = cpu_to_le32(channel->rcid); + req.chunk_size = cpu_to_le32(len); + req.left_size = cpu_to_le32(0); + + return glink_rpm_tx(glink, &req, sizeof(req), data, len, wait); +} + +static int glink_rpm_send(struct rpmsg_endpoint *ept, void *data, int len) +{ + struct glink_channel *channel = to_glink_channel(ept); + + return __glink_rpm_send(channel, data, len, true); +} + +static int glink_rpm_trysend(struct rpmsg_endpoint *ept, void *data, int len) +{ + struct glink_channel *channel = to_glink_channel(ept); + + return __glink_rpm_send(channel, data, len, false); +} + +/* + * Finds the device_node for the glink child interested in this channel. + */ +static struct device_node *glink_rpm_match_channel(struct device_node *node, + const char *channel) +{ + struct device_node *child; + const char *name; + const char *key; + int ret; + + for_each_available_child_of_node(node, child) { + key = "qcom,glink-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 glink_device_ops = { + .create_ept = glink_rpm_create_ept, +}; + +static const struct rpmsg_endpoint_ops glink_endpoint_ops = { + .destroy_ept = glink_rpm_destroy_ept, + .send = glink_rpm_send, + .trysend = glink_rpm_trysend, +}; + +static void glink_rpm_rpdev_release(struct device *dev) +{ + struct rpmsg_device *rpdev = to_rpmsg_device(dev); + struct glink_channel *channel = to_glink_channel(rpdev->ept); + + channel->rpdev = NULL; + kfree(rpdev); +} + +static int glink_rpm_rx_open(struct glink_rpm *glink, unsigned int rcid, + char *name) +{ + struct glink_channel *channel; + struct rpmsg_device *rpdev; + bool create_device = false; + int lcid; + int ret; + + idr_for_each_entry(&glink->lcids, channel, lcid) { + if (!strcmp(channel->name, name)) + break; + } + + if (!channel) { + channel = glink_rpm_alloc_channel(glink, name); + if (IS_ERR(channel)) + return PTR_ERR(channel); + + /* The opening dance was initiated by the remote */ + create_device = true; + } + + mutex_lock(&glink->idr_lock); + ret = idr_alloc(&glink->rcids, channel, rcid, rcid + 1, GFP_KERNEL); + if (ret < 0) { + dev_err(glink->dev, "Unable to insert channel into rcid list\n"); + mutex_unlock(&glink->idr_lock); + goto free_channel; + } + channel->rcid = ret; + mutex_unlock(&glink->idr_lock); + + complete(&channel->open_req); + + if (create_device) { + rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL); + if (!rpdev) { + ret = -ENOMEM; + goto rcid_remove; + } + + rpdev->ept = &channel->ept; + strncpy(rpdev->id.name, name, RPMSG_NAME_SIZE); + rpdev->src = RPMSG_ADDR_ANY; + rpdev->dst = RPMSG_ADDR_ANY; + rpdev->ops = &glink_device_ops; + + rpdev->dev.of_node = glink_rpm_match_channel(glink->dev->of_node, name); + rpdev->dev.parent = glink->dev; + rpdev->dev.release = glink_rpm_rpdev_release; + + ret = rpmsg_register_device(rpdev); + if (ret) + goto free_rpdev; + + channel->rpdev = rpdev; + } + + return 0; + +free_rpdev: + kfree(rpdev); +rcid_remove: + mutex_lock(&glink->idr_lock); + idr_remove(&glink->rcids, channel->rcid); + channel->rcid = 0; + mutex_unlock(&glink->idr_lock); +free_channel: + /* Release the reference, iff we took it */ + if (create_device) + kref_put(&channel->refcount, glink_rpm_channel_release); + + return ret; +} + +static void glink_rpm_rx_close(struct glink_rpm *glink, unsigned int rcid) +{ + struct rpmsg_channel_info chinfo; + struct glink_channel *channel; + + channel = idr_find(&glink->rcids, rcid); + if (WARN(!channel, "close request on unknown channel\n")) + return; + + if (channel->rpdev) { + strncpy(chinfo.name, channel->name, sizeof(chinfo.name)); + chinfo.src = RPMSG_ADDR_ANY; + chinfo.dst = RPMSG_ADDR_ANY; + + rpmsg_unregister_device(glink->dev, &chinfo); + } + + glink_rpm_send_close_ack(glink, channel->rcid); + + mutex_lock(&glink->idr_lock); + idr_remove(&glink->rcids, channel->rcid); + channel->rcid = 0; + mutex_unlock(&glink->idr_lock); + + kref_put(&channel->refcount, glink_rpm_channel_release); +} + +static void glink_rpm_rx_close_ack(struct glink_rpm *glink, unsigned int lcid) +{ + struct glink_channel *channel; + + channel = idr_find(&glink->lcids, lcid); + if (WARN(!channel, "close ack on unknown channel\n")) + return; + + mutex_lock(&glink->idr_lock); + idr_remove(&glink->lcids, channel->lcid); + channel->lcid = 0; + mutex_unlock(&glink->idr_lock); + + kref_put(&channel->refcount, glink_rpm_channel_release); +} + +static void glink_rpm_work(struct work_struct *work) +{ + struct glink_rpm *glink = container_of(work, struct glink_rpm, rx_work); + struct glink_defer_cmd *dcmd; + struct glink_msg *msg; + unsigned long flags; + unsigned int param1; + unsigned int param2; + unsigned int cmd; + + for (;;) { + spin_lock_irqsave(&glink->rx_lock, flags); + if (list_empty(&glink->rx_queue)) { + spin_unlock_irqrestore(&glink->rx_lock, flags); + break; + } + dcmd = list_first_entry(&glink->rx_queue, struct glink_defer_cmd, node); + list_del(&dcmd->node); + spin_unlock_irqrestore(&glink->rx_lock, flags); + + msg = &dcmd->msg; + cmd = le16_to_cpu(msg->cmd); + param1 = le16_to_cpu(msg->param1); + param2 = le32_to_cpu(msg->param2); + + switch (cmd) { + case RPM_CMD_VERSION: + glink_rpm_send_version_ack(glink); + break; + case RPM_CMD_VERSION_ACK: + break; + case RPM_CMD_OPEN: + glink_rpm_rx_open(glink, param1, msg->data); + break; + case RPM_CMD_CLOSE: + glink_rpm_rx_close(glink, param1); + break; + case RPM_CMD_CLOSE_ACK: + glink_rpm_rx_close_ack(glink, param1); + break; + default: + WARN(1, "Unknown defer object %d\n", cmd); + break; + } + + kfree(dcmd); + } +} + +static int glink_rpm_parse_toc(struct device *dev, + void __iomem *msg_ram, + size_t msg_ram_size, + struct glink_rpm_pipe *rx, + struct glink_rpm_pipe *tx) +{ + struct rpm_toc *toc; + int num_entries; + unsigned int id; + size_t offset; + size_t size; + void *buf; + int i; + + buf = kzalloc(RPM_TOC_SIZE, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + __ioread32_copy(buf, msg_ram + msg_ram_size - RPM_TOC_SIZE, + RPM_TOC_SIZE / sizeof(u32)); + + toc = buf; + + if (le32_to_cpu(toc->magic) != RPM_TOC_MAGIC) { + dev_err(dev, "RPM TOC has invalid magic\n"); + goto err_inval; + } + + num_entries = le32_to_cpu(toc->count); + if (num_entries > RPM_TOC_MAX_ENTRIES) { + dev_err(dev, "Invalid number of toc entries\n"); + goto err_inval; + } + + for (i = 0; i < num_entries; i++) { + id = le32_to_cpu(toc->entries[i].id); + offset = le32_to_cpu(toc->entries[i].offset); + size = le32_to_cpu(toc->entries[i].size); + + if (offset > msg_ram_size || offset + size > msg_ram_size) { + dev_err(dev, "TOC entry with invalid size\n"); + continue; + } + + switch (id) { + case RPM_RX_FIFO_ID: + rx->length = size; + + rx->tail = msg_ram + offset; + rx->head = msg_ram + offset + sizeof(u32); + rx->fifo = msg_ram + offset + 2 * sizeof(u32); + break; + case RPM_TX_FIFO_ID: + tx->length = size; + + tx->tail = msg_ram + offset; + tx->head = msg_ram + offset + sizeof(u32); + tx->fifo = msg_ram + offset + 2 * sizeof(u32); + break; + } + } + + if (!rx->fifo || !tx->fifo) { + dev_err(dev, "Unable to find rx and tx descriptors\n"); + goto err_inval; + } + + kfree(buf); + return 0; + +err_inval: + kfree(buf); + return -EINVAL; +} + +static int glink_rpm_probe(struct platform_device *pdev) +{ + struct glink_rpm *glink; + struct device_node *np; + void __iomem *msg_ram; + size_t msg_ram_size; + struct device *dev = &pdev->dev; + struct resource r; + int irq; + int ret; + + glink = devm_kzalloc(dev, sizeof(*glink), GFP_KERNEL); + if (!glink) + return -ENOMEM; + + glink->dev = dev; + + mutex_init(&glink->tx_lock); + spin_lock_init(&glink->rx_lock); + INIT_LIST_HEAD(&glink->rx_queue); + INIT_WORK(&glink->rx_work, glink_rpm_work); + + mutex_init(&glink->idr_lock); + idr_init(&glink->lcids); + idr_init(&glink->rcids); + + glink->mbox_client.dev = &pdev->dev; + glink->mbox_chan = mbox_request_channel(&glink->mbox_client, 0); + if (IS_ERR(glink->mbox_chan)) { + if (PTR_ERR(glink->mbox_chan) != -EPROBE_DEFER) + dev_err(&pdev->dev, "failed to acquire IPC channel\n"); + return PTR_ERR(glink->mbox_chan); + } + + np = of_parse_phandle(dev->of_node, "qcom,rpm-msg-ram", 0); + ret = of_address_to_resource(np, 0, &r); + of_node_put(np); + if (ret) + return ret; + + msg_ram = devm_ioremap(dev, r.start, resource_size(&r)); + msg_ram_size = resource_size(&r); + if (!msg_ram) + return -ENOMEM; + + ret = glink_rpm_parse_toc(dev, msg_ram, msg_ram_size, + &glink->rx_pipe, &glink->tx_pipe); + if (ret) + return ret; + + writel(0, glink->tx_pipe.head); + writel(0, glink->rx_pipe.tail); + + irq = platform_get_irq(pdev, 0); + ret = devm_request_irq(dev, irq, + glink_rpm_intr, + IRQF_NO_SUSPEND | IRQF_SHARED, + "glink-rpm", glink); + if (ret) { + dev_err(dev, "Failed to request IRQ\n"); + return ret; + } + + glink->irq = irq; + + ret = glink_rpm_send_version(glink); + if (ret) + return ret; + + platform_set_drvdata(pdev, glink); + + return 0; +} + +static int glink_rpm_remove_device(struct device *dev, void *data) +{ + device_unregister(dev); + + return 0; +} + +static int glink_rpm_remove(struct platform_device *pdev) +{ + struct glink_rpm *glink = platform_get_drvdata(pdev); + struct glink_channel *channel; + int cid; + int ret; + + disable_irq(glink->irq); + cancel_work_sync(&glink->rx_work); + + ret = device_for_each_child(glink->dev, NULL, glink_rpm_remove_device); + if (ret) + dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret); + + /* Release any defunct local channels, waiting for close-ack */ + idr_for_each_entry(&glink->lcids, channel, cid) + kref_put(&channel->refcount, glink_rpm_channel_release); + + idr_destroy(&glink->lcids); + idr_destroy(&glink->rcids); + + return 0; +} + +static const struct of_device_id glink_rpm_of_match[] = { + { .compatible = "qcom,glink-rpm" }, + {} +}; +MODULE_DEVICE_TABLE(of, glink_rpm_of_match); + +static struct platform_driver glink_rpm_driver = { + .probe = glink_rpm_probe, + .remove = glink_rpm_remove, + .driver = { + .name = "qcom_glink_rpm", + .of_match_table = glink_rpm_of_match, + }, +}; + +static int __init glink_rpm_init(void) +{ + return platform_driver_register(&glink_rpm_driver); +} +subsys_initcall(glink_rpm_init); + +static void __exit glink_rpm_exit(void) +{ + platform_driver_unregister(&glink_rpm_driver); +} +module_exit(glink_rpm_exit); + +MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@linaro.org>"); +MODULE_DESCRIPTION("Qualcomm GLINK RPM driver"); +MODULE_LICENSE("GPL v2"); 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