diff options
Diffstat (limited to 'drivers/firmware/ti_sci.c')
| -rw-r--r-- | drivers/firmware/ti_sci.c | 790 |
1 files changed, 790 insertions, 0 deletions
diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c new file mode 100644 index 000000000000..5e99d7c18276 --- /dev/null +++ b/drivers/firmware/ti_sci.c @@ -0,0 +1,790 @@ +/* + * 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"); |