/* * 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 #include #include #include #include #include #include #include #include #include #include #include #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");