--- /dev/null
+/*
+ * Texas Instruments System Control Interface Protocol Driver
+ *
+ * Copyright (C) 2015-2016 Texas Instruments Incorporated - http://www.ti.com/
+ * Nishanth Menon
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+#include <linux/bitmap.h>
+#include <linux/debugfs.h>
+#include <linux/export.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_client.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/semaphore.h>
+#include <linux/slab.h>
+#include <linux/soc/ti/ti-msgmgr.h>
+#include <linux/soc/ti/ti_sci_protocol.h>
+
+#include "ti_sci.h"
+
+/* List of all TI SCI devices active in system */
+static LIST_HEAD(ti_sci_list);
+/* Protection for the entire list */
+static DEFINE_MUTEX(ti_sci_list_mutex);
+
+/**
+ * struct ti_sci_xfer - Structure representing a message flow
+ * @tx_message: Transmit message
+ * @rx_len: Receive message length
+ * @xfer_buf: Preallocated buffer to store receive message
+ * Since we work with request-ACK protocol, we can
+ * reuse the same buffer for the rx path as we
+ * use for the tx path.
+ * @done: completion event
+ */
+struct ti_sci_xfer {
+ struct ti_msgmgr_message tx_message;
+ u8 rx_len;
+ u8 *xfer_buf;
+ struct completion done;
+};
+
+/**
+ * struct ti_sci_xfers_info - Structure to manage transfer information
+ * @sem_xfer_count: Counting Semaphore for managing max simultaneous
+ * Messages.
+ * @xfer_block: Preallocated Message array
+ * @xfer_alloc_table: Bitmap table for allocated messages.
+ * Index of this bitmap table is also used for message
+ * sequence identifier.
+ * @xfer_lock: Protection for message allocation
+ */
+struct ti_sci_xfers_info {
+ struct semaphore sem_xfer_count;
+ struct ti_sci_xfer *xfer_block;
+ unsigned long *xfer_alloc_table;
+ /* protect transfer allocation */
+ spinlock_t xfer_lock;
+};
+
+/**
+ * struct ti_sci_desc - Description of SoC integration
+ * @host_id: Host identifier representing the compute entity
+ * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds)
+ * @max_msgs: Maximum number of messages that can be pending
+ * simultaneously in the system
+ * @max_msg_size: Maximum size of data per message that can be handled.
+ */
+struct ti_sci_desc {
+ u8 host_id;
+ int max_rx_timeout_ms;
+ int max_msgs;
+ int max_msg_size;
+};
+
+/**
+ * struct ti_sci_info - Structure representing a TI SCI instance
+ * @dev: Device pointer
+ * @desc: SoC description for this instance
+ * @d: Debugfs file entry
+ * @debug_region: Memory region where the debug message are available
+ * @debug_region_size: Debug region size
+ * @debug_buffer: Buffer allocated to copy debug messages.
+ * @handle: Instance of TI SCI handle to send to clients.
+ * @cl: Mailbox Client
+ * @chan_tx: Transmit mailbox channel
+ * @chan_rx: Receive mailbox channel
+ * @minfo: Message info
+ * @node: list head
+ * @users: Number of users of this instance
+ */
+struct ti_sci_info {
+ struct device *dev;
+ const struct ti_sci_desc *desc;
+ struct dentry *d;
+ void __iomem *debug_region;
+ char *debug_buffer;
+ size_t debug_region_size;
+ struct ti_sci_handle handle;
+ struct mbox_client cl;
+ struct mbox_chan *chan_tx;
+ struct mbox_chan *chan_rx;
+ struct ti_sci_xfers_info minfo;
+ struct list_head node;
+ /* protected by ti_sci_list_mutex */
+ int users;
+};
+
+#define cl_to_ti_sci_info(c) container_of(c, struct ti_sci_info, cl)
+#define handle_to_ti_sci_info(h) container_of(h, struct ti_sci_info, handle)
+
+#ifdef CONFIG_DEBUG_FS
+
+/**
+ * ti_sci_debug_show() - Helper to dump the debug log
+ * @s: sequence file pointer
+ * @unused: unused.
+ *
+ * Return: 0
+ */
+static int ti_sci_debug_show(struct seq_file *s, void *unused)
+{
+ struct ti_sci_info *info = s->private;
+
+ memcpy_fromio(info->debug_buffer, info->debug_region,
+ info->debug_region_size);
+ /*
+ * We don't trust firmware to leave NULL terminated last byte (hence
+ * we have allocated 1 extra 0 byte). Since we cannot guarantee any
+ * specific data format for debug messages, We just present the data
+ * in the buffer as is - we expect the messages to be self explanatory.
+ */
+ seq_puts(s, info->debug_buffer);
+ return 0;
+}
+
+/**
+ * ti_sci_debug_open() - debug file open
+ * @inode: inode pointer
+ * @file: file pointer
+ *
+ * Return: result of single_open
+ */
+static int ti_sci_debug_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, ti_sci_debug_show, inode->i_private);
+}
+
+/* log file operations */
+static const struct file_operations ti_sci_debug_fops = {
+ .open = ti_sci_debug_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+/**
+ * ti_sci_debugfs_create() - Create log debug file
+ * @pdev: platform device pointer
+ * @info: Pointer to SCI entity information
+ *
+ * Return: 0 if all went fine, else corresponding error.
+ */
+static int ti_sci_debugfs_create(struct platform_device *pdev,
+ struct ti_sci_info *info)
+{
+ struct device *dev = &pdev->dev;
+ struct resource *res;
+ char debug_name[50] = "ti_sci_debug@";
+
+ /* Debug region is optional */
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+ "debug_messages");
+ info->debug_region = devm_ioremap_resource(dev, res);
+ if (IS_ERR(info->debug_region))
+ return 0;
+ info->debug_region_size = resource_size(res);
+
+ info->debug_buffer = devm_kcalloc(dev, info->debug_region_size + 1,
+ sizeof(char), GFP_KERNEL);
+ if (!info->debug_buffer)
+ return -ENOMEM;
+ /* Setup NULL termination */
+ info->debug_buffer[info->debug_region_size] = 0;
+
+ info->d = debugfs_create_file(strncat(debug_name, dev_name(dev),
+ sizeof(debug_name)),
+ 0444, NULL, info, &ti_sci_debug_fops);
+ if (IS_ERR(info->d))
+ return PTR_ERR(info->d);
+
+ dev_dbg(dev, "Debug region => %p, size = %zu bytes, resource: %pr\n",
+ info->debug_region, info->debug_region_size, res);
+ return 0;
+}
+
+/**
+ * ti_sci_debugfs_destroy() - clean up log debug file
+ * @pdev: platform device pointer
+ * @info: Pointer to SCI entity information
+ */
+static void ti_sci_debugfs_destroy(struct platform_device *pdev,
+ struct ti_sci_info *info)
+{
+ if (IS_ERR(info->debug_region))
+ return;
+
+ debugfs_remove(info->d);
+}
+#else /* CONFIG_DEBUG_FS */
+static inline int ti_sci_debugfs_create(struct platform_device *dev,
+ struct ti_sci_info *info)
+{
+ return 0;
+}
+
+static inline void ti_sci_debugfs_destroy(struct platform_device *dev,
+ struct ti_sci_info *info)
+{
+}
+#endif /* CONFIG_DEBUG_FS */
+
+/**
+ * ti_sci_dump_header_dbg() - Helper to dump a message header.
+ * @dev: Device pointer corresponding to the SCI entity
+ * @hdr: pointer to header.
+ */
+static inline void ti_sci_dump_header_dbg(struct device *dev,
+ struct ti_sci_msg_hdr *hdr)
+{
+ dev_dbg(dev, "MSGHDR:type=0x%04x host=0x%02x seq=0x%02x flags=0x%08x\n",
+ hdr->type, hdr->host, hdr->seq, hdr->flags);
+}
+
+/**
+ * ti_sci_rx_callback() - mailbox client callback for receive messages
+ * @cl: client pointer
+ * @m: mailbox message
+ *
+ * Processes one received message to appropriate transfer information and
+ * signals completion of the transfer.
+ *
+ * NOTE: This function will be invoked in IRQ context, hence should be
+ * as optimal as possible.
+ */
+static void ti_sci_rx_callback(struct mbox_client *cl, void *m)
+{
+ struct ti_sci_info *info = cl_to_ti_sci_info(cl);
+ struct device *dev = info->dev;
+ struct ti_sci_xfers_info *minfo = &info->minfo;
+ struct ti_msgmgr_message *mbox_msg = m;
+ struct ti_sci_msg_hdr *hdr = (struct ti_sci_msg_hdr *)mbox_msg->buf;
+ struct ti_sci_xfer *xfer;
+ u8 xfer_id;
+
+ xfer_id = hdr->seq;
+
+ /*
+ * Are we even expecting this?
+ * NOTE: barriers were implicit in locks used for modifying the bitmap
+ */
+ if (!test_bit(xfer_id, minfo->xfer_alloc_table)) {
+ dev_err(dev, "Message for %d is not expected!\n", xfer_id);
+ return;
+ }
+
+ xfer = &minfo->xfer_block[xfer_id];
+
+ /* Is the message of valid length? */
+ if (mbox_msg->len > info->desc->max_msg_size) {
+ dev_err(dev, "Unable to handle %d xfer(max %d)\n",
+ mbox_msg->len, info->desc->max_msg_size);
+ ti_sci_dump_header_dbg(dev, hdr);
+ return;
+ }
+ if (mbox_msg->len < xfer->rx_len) {
+ dev_err(dev, "Recv xfer %d < expected %d length\n",
+ mbox_msg->len, xfer->rx_len);
+ ti_sci_dump_header_dbg(dev, hdr);
+ return;
+ }
+
+ ti_sci_dump_header_dbg(dev, hdr);
+ /* Take a copy to the rx buffer.. */
+ memcpy(xfer->xfer_buf, mbox_msg->buf, xfer->rx_len);
+ complete(&xfer->done);
+}
+
+/**
+ * ti_sci_get_one_xfer() - Allocate one message
+ * @info: Pointer to SCI entity information
+ * @msg_type: Message type
+ * @msg_flags: Flag to set for the message
+ * @tx_message_size: transmit message size
+ * @rx_message_size: receive message size
+ *
+ * Helper function which is used by various command functions that are
+ * exposed to clients of this driver for allocating a message traffic event.
+ *
+ * This function can sleep depending on pending requests already in the system
+ * for the SCI entity. Further, this also holds a spinlock to maintain integrity
+ * of internal data structures.
+ *
+ * Return: 0 if all went fine, else corresponding error.
+ */
+static struct ti_sci_xfer *ti_sci_get_one_xfer(struct ti_sci_info *info,
+ u16 msg_type, u32 msg_flags,
+ size_t tx_message_size,
+ size_t rx_message_size)
+{
+ struct ti_sci_xfers_info *minfo = &info->minfo;
+ struct ti_sci_xfer *xfer;
+ struct ti_sci_msg_hdr *hdr;
+ unsigned long flags;
+ unsigned long bit_pos;
+ u8 xfer_id;
+ int ret;
+ int timeout;
+
+ /* Ensure we have sane transfer sizes */
+ if (rx_message_size > info->desc->max_msg_size ||
+ tx_message_size > info->desc->max_msg_size ||
+ rx_message_size < sizeof(*hdr) || tx_message_size < sizeof(*hdr))
+ return ERR_PTR(-ERANGE);
+
+ /*
+ * Ensure we have only controlled number of pending messages.
+ * Ideally, we might just have to wait a single message, be
+ * conservative and wait 5 times that..
+ */
+ timeout = msecs_to_jiffies(info->desc->max_rx_timeout_ms) * 5;
+ ret = down_timeout(&minfo->sem_xfer_count, timeout);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ /* Keep the locked section as small as possible */
+ spin_lock_irqsave(&minfo->xfer_lock, flags);
+ bit_pos = find_first_zero_bit(minfo->xfer_alloc_table,
+ info->desc->max_msgs);
+ set_bit(bit_pos, minfo->xfer_alloc_table);
+ spin_unlock_irqrestore(&minfo->xfer_lock, flags);
+
+ /*
+ * We already ensured in probe that we can have max messages that can
+ * fit in hdr.seq - NOTE: this improves access latencies
+ * to predictable O(1) access, BUT, it opens us to risk if
+ * remote misbehaves with corrupted message sequence responses.
+ * If that happens, we are going to be messed up anyways..
+ */
+ xfer_id = (u8)bit_pos;
+
+ xfer = &minfo->xfer_block[xfer_id];
+
+ hdr = (struct ti_sci_msg_hdr *)xfer->tx_message.buf;
+ xfer->tx_message.len = tx_message_size;
+ xfer->rx_len = (u8)rx_message_size;
+
+ reinit_completion(&xfer->done);
+
+ hdr->seq = xfer_id;
+ hdr->type = msg_type;
+ hdr->host = info->desc->host_id;
+ hdr->flags = msg_flags;
+
+ return xfer;
+}
+
+/**
+ * ti_sci_put_one_xfer() - Release a message
+ * @minfo: transfer info pointer
+ * @xfer: message that was reserved by ti_sci_get_one_xfer
+ *
+ * This holds a spinlock to maintain integrity of internal data structures.
+ */
+static void ti_sci_put_one_xfer(struct ti_sci_xfers_info *minfo,
+ struct ti_sci_xfer *xfer)
+{
+ unsigned long flags;
+ struct ti_sci_msg_hdr *hdr;
+ u8 xfer_id;
+
+ hdr = (struct ti_sci_msg_hdr *)xfer->tx_message.buf;
+ xfer_id = hdr->seq;
+
+ /*
+ * Keep the locked section as small as possible
+ * NOTE: we might escape with smp_mb and no lock here..
+ * but just be conservative and symmetric.
+ */
+ spin_lock_irqsave(&minfo->xfer_lock, flags);
+ clear_bit(xfer_id, minfo->xfer_alloc_table);
+ spin_unlock_irqrestore(&minfo->xfer_lock, flags);
+
+ /* Increment the count for the next user to get through */
+ up(&minfo->sem_xfer_count);
+}
+
+/**
+ * ti_sci_do_xfer() - Do one transfer
+ * @info: Pointer to SCI entity information
+ * @xfer: Transfer to initiate and wait for response
+ *
+ * Return: -ETIMEDOUT in case of no response, if transmit error,
+ * return corresponding error, else if all goes well,
+ * return 0.
+ */
+static inline int ti_sci_do_xfer(struct ti_sci_info *info,
+ struct ti_sci_xfer *xfer)
+{
+ int ret;
+ int timeout;
+ struct device *dev = info->dev;
+
+ ret = mbox_send_message(info->chan_tx, &xfer->tx_message);
+ if (ret < 0)
+ return ret;
+
+ ret = 0;
+
+ /* And we wait for the response. */
+ timeout = msecs_to_jiffies(info->desc->max_rx_timeout_ms);
+ if (!wait_for_completion_timeout(&xfer->done, timeout)) {
+ dev_err(dev, "Mbox timedout in resp(caller: %pF)\n",
+ (void *)_RET_IP_);
+ ret = -ETIMEDOUT;
+ }
+ /*
+ * NOTE: we might prefer not to need the mailbox ticker to manage the
+ * transfer queueing since the protocol layer queues things by itself.
+ * Unfortunately, we have to kick the mailbox framework after we have
+ * received our message.
+ */
+ mbox_client_txdone(info->chan_tx, ret);
+
+ return ret;
+}
+
+/**
+ * ti_sci_cmd_get_revision() - command to get the revision of the SCI entity
+ * @info: Pointer to SCI entity information
+ *
+ * Updates the SCI information in the internal data structure.
+ *
+ * Return: 0 if all went fine, else return appropriate error.
+ */
+static int ti_sci_cmd_get_revision(struct ti_sci_info *info)
+{
+ struct device *dev = info->dev;
+ struct ti_sci_handle *handle = &info->handle;
+ struct ti_sci_version_info *ver = &handle->version;
+ struct ti_sci_msg_resp_version *rev_info;
+ struct ti_sci_xfer *xfer;
+ int ret;
+
+ /* No need to setup flags since it is expected to respond */
+ xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_VERSION,
+ 0x0, sizeof(struct ti_sci_msg_hdr),
+ sizeof(*rev_info));
+ if (IS_ERR(xfer)) {
+ ret = PTR_ERR(xfer);
+ dev_err(dev, "Message alloc failed(%d)\n", ret);
+ return ret;
+ }
+
+ rev_info = (struct ti_sci_msg_resp_version *)xfer->xfer_buf;
+
+ ret = ti_sci_do_xfer(info, xfer);
+ if (ret) {
+ dev_err(dev, "Mbox send fail %d\n", ret);
+ goto fail;
+ }
+
+ ver->abi_major = rev_info->abi_major;
+ ver->abi_minor = rev_info->abi_minor;
+ ver->firmware_revision = rev_info->firmware_revision;
+ strncpy(ver->firmware_description, rev_info->firmware_description,
+ sizeof(ver->firmware_description));
+
+fail:
+ ti_sci_put_one_xfer(&info->minfo, xfer);
+ return ret;
+}
+
+/**
+ * ti_sci_get_handle() - Get the TI SCI handle for a device
+ * @dev: Pointer to device for which we want SCI handle
+ *
+ * NOTE: The function does not track individual clients of the framework
+ * and is expected to be maintained by caller of TI SCI protocol library.
+ * ti_sci_put_handle must be balanced with successful ti_sci_get_handle
+ * Return: pointer to handle if successful, else:
+ * -EPROBE_DEFER if the instance is not ready
+ * -ENODEV if the required node handler is missing
+ * -EINVAL if invalid conditions are encountered.
+ */
+const struct ti_sci_handle *ti_sci_get_handle(struct device *dev)
+{
+ struct device_node *ti_sci_np;
+ struct list_head *p;
+ struct ti_sci_handle *handle = NULL;
+ struct ti_sci_info *info;
+
+ if (!dev) {
+ pr_err("I need a device pointer\n");
+ return ERR_PTR(-EINVAL);
+ }
+ ti_sci_np = of_get_parent(dev->of_node);
+ if (!ti_sci_np) {
+ dev_err(dev, "No OF information\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ mutex_lock(&ti_sci_list_mutex);
+ list_for_each(p, &ti_sci_list) {
+ info = list_entry(p, struct ti_sci_info, node);
+ if (ti_sci_np == info->dev->of_node) {
+ handle = &info->handle;
+ info->users++;
+ break;
+ }
+ }
+ mutex_unlock(&ti_sci_list_mutex);
+ of_node_put(ti_sci_np);
+
+ if (!handle)
+ return ERR_PTR(-EPROBE_DEFER);
+
+ return handle;
+}
+EXPORT_SYMBOL_GPL(ti_sci_get_handle);
+
+/**
+ * ti_sci_put_handle() - Release the handle acquired by ti_sci_get_handle
+ * @handle: Handle acquired by ti_sci_get_handle
+ *
+ * NOTE: The function does not track individual clients of the framework
+ * and is expected to be maintained by caller of TI SCI protocol library.
+ * ti_sci_put_handle must be balanced with successful ti_sci_get_handle
+ *
+ * Return: 0 is successfully released
+ * if an error pointer was passed, it returns the error value back,
+ * if null was passed, it returns -EINVAL;
+ */
+int ti_sci_put_handle(const struct ti_sci_handle *handle)
+{
+ struct ti_sci_info *info;
+
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+ if (!handle)
+ return -EINVAL;
+
+ info = handle_to_ti_sci_info(handle);
+ mutex_lock(&ti_sci_list_mutex);
+ if (!WARN_ON(!info->users))
+ info->users--;
+ mutex_unlock(&ti_sci_list_mutex);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(ti_sci_put_handle);
+
+static void devm_ti_sci_release(struct device *dev, void *res)
+{
+ const struct ti_sci_handle **ptr = res;
+ const struct ti_sci_handle *handle = *ptr;
+ int ret;
+
+ ret = ti_sci_put_handle(handle);
+ if (ret)
+ dev_err(dev, "failed to put handle %d\n", ret);
+}
+
+/**
+ * devm_ti_sci_get_handle() - Managed get handle
+ * @dev: device for which we want SCI handle for.
+ *
+ * NOTE: This releases the handle once the device resources are
+ * no longer needed. MUST NOT BE released with ti_sci_put_handle.
+ * The function does not track individual clients of the framework
+ * and is expected to be maintained by caller of TI SCI protocol library.
+ *
+ * Return: 0 if all went fine, else corresponding error.
+ */
+const struct ti_sci_handle *devm_ti_sci_get_handle(struct device *dev)
+{
+ const struct ti_sci_handle **ptr;
+ const struct ti_sci_handle *handle;
+
+ ptr = devres_alloc(devm_ti_sci_release, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+ handle = ti_sci_get_handle(dev);
+
+ if (!IS_ERR(handle)) {
+ *ptr = handle;
+ devres_add(dev, ptr);
+ } else {
+ devres_free(ptr);
+ }
+
+ return handle;
+}
+EXPORT_SYMBOL_GPL(devm_ti_sci_get_handle);
+
+/* Description for K2G */
+static const struct ti_sci_desc ti_sci_pmmc_k2g_desc = {
+ .host_id = 2,
+ /* Conservative duration */
+ .max_rx_timeout_ms = 1000,
+ /* Limited by MBOX_TX_QUEUE_LEN. K2G can handle upto 128 messages! */
+ .max_msgs = 20,
+ .max_msg_size = 64,
+};
+
+static const struct of_device_id ti_sci_of_match[] = {
+ {.compatible = "ti,k2g-sci", .data = &ti_sci_pmmc_k2g_desc},
+ { /* Sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, ti_sci_of_match);
+
+static int ti_sci_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ const struct of_device_id *of_id;
+ const struct ti_sci_desc *desc;
+ struct ti_sci_xfer *xfer;
+ struct ti_sci_info *info = NULL;
+ struct ti_sci_xfers_info *minfo;
+ struct mbox_client *cl;
+ int ret = -EINVAL;
+ int i;
+
+ of_id = of_match_device(ti_sci_of_match, dev);
+ if (!of_id) {
+ dev_err(dev, "OF data missing\n");
+ return -EINVAL;
+ }
+ desc = of_id->data;
+
+ info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+
+ info->dev = dev;
+ info->desc = desc;
+ INIT_LIST_HEAD(&info->node);
+ minfo = &info->minfo;
+
+ /*
+ * Pre-allocate messages
+ * NEVER allocate more than what we can indicate in hdr.seq
+ * if we have data description bug, force a fix..
+ */
+ if (WARN_ON(desc->max_msgs >=
+ 1 << 8 * sizeof(((struct ti_sci_msg_hdr *)0)->seq)))
+ return -EINVAL;
+
+ minfo->xfer_block = devm_kcalloc(dev,
+ desc->max_msgs,
+ sizeof(*minfo->xfer_block),
+ GFP_KERNEL);
+ if (!minfo->xfer_block)
+ return -ENOMEM;
+
+ minfo->xfer_alloc_table = devm_kzalloc(dev,
+ BITS_TO_LONGS(desc->max_msgs)
+ * sizeof(unsigned long),
+ GFP_KERNEL);
+ if (!minfo->xfer_alloc_table)
+ return -ENOMEM;
+ bitmap_zero(minfo->xfer_alloc_table, desc->max_msgs);
+
+ /* Pre-initialize the buffer pointer to pre-allocated buffers */
+ for (i = 0, xfer = minfo->xfer_block; i < desc->max_msgs; i++, xfer++) {
+ xfer->xfer_buf = devm_kcalloc(dev, 1, desc->max_msg_size,
+ GFP_KERNEL);
+ if (!xfer->xfer_buf)
+ return -ENOMEM;
+
+ xfer->tx_message.buf = xfer->xfer_buf;
+ init_completion(&xfer->done);
+ }
+
+ ret = ti_sci_debugfs_create(pdev, info);
+ if (ret)
+ dev_warn(dev, "Failed to create debug file\n");
+
+ platform_set_drvdata(pdev, info);
+
+ cl = &info->cl;
+ cl->dev = dev;
+ cl->tx_block = false;
+ cl->rx_callback = ti_sci_rx_callback;
+ cl->knows_txdone = true;
+
+ spin_lock_init(&minfo->xfer_lock);
+ sema_init(&minfo->sem_xfer_count, desc->max_msgs);
+
+ info->chan_rx = mbox_request_channel_byname(cl, "rx");
+ if (IS_ERR(info->chan_rx)) {
+ ret = PTR_ERR(info->chan_rx);
+ goto out;
+ }
+
+ info->chan_tx = mbox_request_channel_byname(cl, "tx");
+ if (IS_ERR(info->chan_tx)) {
+ ret = PTR_ERR(info->chan_tx);
+ goto out;
+ }
+ ret = ti_sci_cmd_get_revision(info);
+ if (ret) {
+ dev_err(dev, "Unable to communicate with TISCI(%d)\n", ret);
+ goto out;
+ }
+
+ dev_info(dev, "ABI: %d.%d (firmware rev 0x%04x '%s')\n",
+ info->handle.version.abi_major, info->handle.version.abi_minor,
+ info->handle.version.firmware_revision,
+ info->handle.version.firmware_description);
+
+ mutex_lock(&ti_sci_list_mutex);
+ list_add_tail(&info->node, &ti_sci_list);
+ mutex_unlock(&ti_sci_list_mutex);
+
+ return of_platform_populate(dev->of_node, NULL, NULL, dev);
+out:
+ if (!IS_ERR(info->chan_tx))
+ mbox_free_channel(info->chan_tx);
+ if (!IS_ERR(info->chan_rx))
+ mbox_free_channel(info->chan_rx);
+ debugfs_remove(info->d);
+ return ret;
+}
+
+static int ti_sci_remove(struct platform_device *pdev)
+{
+ struct ti_sci_info *info;
+ struct device *dev = &pdev->dev;
+ int ret = 0;
+
+ of_platform_depopulate(dev);
+
+ info = platform_get_drvdata(pdev);
+
+ mutex_lock(&ti_sci_list_mutex);
+ if (info->users)
+ ret = -EBUSY;
+ else
+ list_del(&info->node);
+ mutex_unlock(&ti_sci_list_mutex);
+
+ if (!ret) {
+ ti_sci_debugfs_destroy(pdev, info);
+
+ /* Safe to free channels since no more users */
+ mbox_free_channel(info->chan_tx);
+ mbox_free_channel(info->chan_rx);
+ }
+
+ return ret;
+}
+
+static struct platform_driver ti_sci_driver = {
+ .probe = ti_sci_probe,
+ .remove = ti_sci_remove,
+ .driver = {
+ .name = "ti-sci",
+ .of_match_table = of_match_ptr(ti_sci_of_match),
+ },
+};
+module_platform_driver(ti_sci_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("TI System Control Interface(SCI) driver");
+MODULE_AUTHOR("Nishanth Menon");
+MODULE_ALIAS("platform:ti-sci");
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff