diff options
Diffstat (limited to 'drivers/firmware/arm_scmi/driver.c')
| -rw-r--r-- | drivers/firmware/arm_scmi/driver.c | 990 |
1 files changed, 990 insertions, 0 deletions
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c new file mode 100644 index 000000000..8d2408284 --- /dev/null +++ b/drivers/firmware/arm_scmi/driver.c @@ -0,0 +1,990 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * System Control and Management Interface (SCMI) Message Protocol driver + * + * SCMI Message Protocol is used between the System Control Processor(SCP) + * and the Application Processors(AP). The Message Handling Unit(MHU) + * provides a mechanism for inter-processor communication between SCP's + * Cortex M3 and AP. + * + * SCP offers control and management of the core/cluster power states, + * various power domain DVFS including the core/cluster, certain system + * clocks configuration, thermal sensors and many others. + * + * Copyright (C) 2018 ARM Ltd. + */ + +#include <linux/bitmap.h> +#include <linux/export.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/ktime.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/processor.h> +#include <linux/slab.h> + +#include "common.h" +#include "notify.h" + +#define CREATE_TRACE_POINTS +#include <trace/events/scmi.h> + +enum scmi_error_codes { + SCMI_SUCCESS = 0, /* Success */ + SCMI_ERR_SUPPORT = -1, /* Not supported */ + SCMI_ERR_PARAMS = -2, /* Invalid Parameters */ + SCMI_ERR_ACCESS = -3, /* Invalid access/permission denied */ + SCMI_ERR_ENTRY = -4, /* Not found */ + SCMI_ERR_RANGE = -5, /* Value out of range */ + SCMI_ERR_BUSY = -6, /* Device busy */ + SCMI_ERR_COMMS = -7, /* Communication Error */ + SCMI_ERR_GENERIC = -8, /* Generic Error */ + SCMI_ERR_HARDWARE = -9, /* Hardware Error */ + SCMI_ERR_PROTOCOL = -10,/* Protocol Error */ +}; + +/* List of all SCMI devices active in system */ +static LIST_HEAD(scmi_list); +/* Protection for the entire list */ +static DEFINE_MUTEX(scmi_list_mutex); +/* Track the unique id for the transfers for debug & profiling purpose */ +static atomic_t transfer_last_id; + +/** + * struct scmi_xfers_info - Structure to manage transfer information + * + * @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 scmi_xfers_info { + struct scmi_xfer *xfer_block; + unsigned long *xfer_alloc_table; + spinlock_t xfer_lock; +}; + +/** + * struct scmi_info - Structure representing a SCMI instance + * + * @dev: Device pointer + * @desc: SoC description for this instance + * @version: SCMI revision information containing protocol version, + * implementation version and (sub-)vendor identification. + * @handle: Instance of SCMI handle to send to clients + * @tx_minfo: Universal Transmit Message management info + * @rx_minfo: Universal Receive Message management info + * @tx_idr: IDR object to map protocol id to Tx channel info pointer + * @rx_idr: IDR object to map protocol id to Rx channel info pointer + * @protocols_imp: List of protocols implemented, currently maximum of + * MAX_PROTOCOLS_IMP elements allocated by the base protocol + * @node: List head + * @users: Number of users of this instance + */ +struct scmi_info { + struct device *dev; + const struct scmi_desc *desc; + struct scmi_revision_info version; + struct scmi_handle handle; + struct scmi_xfers_info tx_minfo; + struct scmi_xfers_info rx_minfo; + struct idr tx_idr; + struct idr rx_idr; + u8 *protocols_imp; + struct list_head node; + int users; +}; + +#define handle_to_scmi_info(h) container_of(h, struct scmi_info, handle) + +static const int scmi_linux_errmap[] = { + /* better than switch case as long as return value is continuous */ + 0, /* SCMI_SUCCESS */ + -EOPNOTSUPP, /* SCMI_ERR_SUPPORT */ + -EINVAL, /* SCMI_ERR_PARAM */ + -EACCES, /* SCMI_ERR_ACCESS */ + -ENOENT, /* SCMI_ERR_ENTRY */ + -ERANGE, /* SCMI_ERR_RANGE */ + -EBUSY, /* SCMI_ERR_BUSY */ + -ECOMM, /* SCMI_ERR_COMMS */ + -EIO, /* SCMI_ERR_GENERIC */ + -EREMOTEIO, /* SCMI_ERR_HARDWARE */ + -EPROTO, /* SCMI_ERR_PROTOCOL */ +}; + +static inline int scmi_to_linux_errno(int errno) +{ + int err_idx = -errno; + + if (err_idx >= SCMI_SUCCESS && err_idx < ARRAY_SIZE(scmi_linux_errmap)) + return scmi_linux_errmap[err_idx]; + return -EIO; +} + +/** + * scmi_dump_header_dbg() - Helper to dump a message header. + * + * @dev: Device pointer corresponding to the SCMI entity + * @hdr: pointer to header. + */ +static inline void scmi_dump_header_dbg(struct device *dev, + struct scmi_msg_hdr *hdr) +{ + dev_dbg(dev, "Message ID: %x Sequence ID: %x Protocol: %x\n", + hdr->id, hdr->seq, hdr->protocol_id); +} + +/** + * scmi_xfer_get() - Allocate one message + * + * @handle: Pointer to SCMI entity handle + * @minfo: Pointer to Tx/Rx Message management info based on channel type + * + * Helper function which is used by various message 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 SCMI 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 scmi_xfer *scmi_xfer_get(const struct scmi_handle *handle, + struct scmi_xfers_info *minfo) +{ + u16 xfer_id; + struct scmi_xfer *xfer; + unsigned long flags, bit_pos; + struct scmi_info *info = handle_to_scmi_info(handle); + + /* 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_msg); + if (bit_pos == info->desc->max_msg) { + spin_unlock_irqrestore(&minfo->xfer_lock, flags); + return ERR_PTR(-ENOMEM); + } + set_bit(bit_pos, minfo->xfer_alloc_table); + spin_unlock_irqrestore(&minfo->xfer_lock, flags); + + xfer_id = bit_pos; + + xfer = &minfo->xfer_block[xfer_id]; + xfer->hdr.seq = xfer_id; + reinit_completion(&xfer->done); + xfer->transfer_id = atomic_inc_return(&transfer_last_id); + + return xfer; +} + +/** + * __scmi_xfer_put() - Release a message + * + * @minfo: Pointer to Tx/Rx Message management info based on channel type + * @xfer: message that was reserved by scmi_xfer_get + * + * This holds a spinlock to maintain integrity of internal data structures. + */ +static void +__scmi_xfer_put(struct scmi_xfers_info *minfo, struct scmi_xfer *xfer) +{ + unsigned long flags; + + /* + * 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->hdr.seq, minfo->xfer_alloc_table); + spin_unlock_irqrestore(&minfo->xfer_lock, flags); +} + +static void scmi_handle_notification(struct scmi_chan_info *cinfo, u32 msg_hdr) +{ + struct scmi_xfer *xfer; + struct device *dev = cinfo->dev; + struct scmi_info *info = handle_to_scmi_info(cinfo->handle); + struct scmi_xfers_info *minfo = &info->rx_minfo; + ktime_t ts; + + ts = ktime_get_boottime(); + xfer = scmi_xfer_get(cinfo->handle, minfo); + if (IS_ERR(xfer)) { + dev_err(dev, "failed to get free message slot (%ld)\n", + PTR_ERR(xfer)); + info->desc->ops->clear_channel(cinfo); + return; + } + + unpack_scmi_header(msg_hdr, &xfer->hdr); + scmi_dump_header_dbg(dev, &xfer->hdr); + info->desc->ops->fetch_notification(cinfo, info->desc->max_msg_size, + xfer); + scmi_notify(cinfo->handle, xfer->hdr.protocol_id, + xfer->hdr.id, xfer->rx.buf, xfer->rx.len, ts); + + trace_scmi_rx_done(xfer->transfer_id, xfer->hdr.id, + xfer->hdr.protocol_id, xfer->hdr.seq, + MSG_TYPE_NOTIFICATION); + + __scmi_xfer_put(minfo, xfer); + + info->desc->ops->clear_channel(cinfo); +} + +static void scmi_handle_response(struct scmi_chan_info *cinfo, + u16 xfer_id, u8 msg_type) +{ + struct scmi_xfer *xfer; + struct device *dev = cinfo->dev; + struct scmi_info *info = handle_to_scmi_info(cinfo->handle); + struct scmi_xfers_info *minfo = &info->tx_minfo; + + /* Are we even expecting this? */ + if (!test_bit(xfer_id, minfo->xfer_alloc_table)) { + dev_err(dev, "message for %d is not expected!\n", xfer_id); + info->desc->ops->clear_channel(cinfo); + return; + } + + xfer = &minfo->xfer_block[xfer_id]; + /* + * Even if a response was indeed expected on this slot at this point, + * a buggy platform could wrongly reply feeding us an unexpected + * delayed response we're not prepared to handle: bail-out safely + * blaming firmware. + */ + if (unlikely(msg_type == MSG_TYPE_DELAYED_RESP && !xfer->async_done)) { + dev_err(dev, + "Delayed Response for %d not expected! Buggy F/W ?\n", + xfer_id); + info->desc->ops->clear_channel(cinfo); + /* It was unexpected, so nobody will clear the xfer if not us */ + __scmi_xfer_put(minfo, xfer); + return; + } + + /* rx.len could be shrunk in the sync do_xfer, so reset to maxsz */ + if (msg_type == MSG_TYPE_DELAYED_RESP) + xfer->rx.len = info->desc->max_msg_size; + + scmi_dump_header_dbg(dev, &xfer->hdr); + + info->desc->ops->fetch_response(cinfo, xfer); + + trace_scmi_rx_done(xfer->transfer_id, xfer->hdr.id, + xfer->hdr.protocol_id, xfer->hdr.seq, + msg_type); + + if (msg_type == MSG_TYPE_DELAYED_RESP) { + info->desc->ops->clear_channel(cinfo); + complete(xfer->async_done); + } else { + complete(&xfer->done); + } +} + +/** + * scmi_rx_callback() - callback for receiving messages + * + * @cinfo: SCMI channel info + * @msg_hdr: Message header + * + * 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. + */ +void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr) +{ + u16 xfer_id = MSG_XTRACT_TOKEN(msg_hdr); + u8 msg_type = MSG_XTRACT_TYPE(msg_hdr); + + switch (msg_type) { + case MSG_TYPE_NOTIFICATION: + scmi_handle_notification(cinfo, msg_hdr); + break; + case MSG_TYPE_COMMAND: + case MSG_TYPE_DELAYED_RESP: + scmi_handle_response(cinfo, xfer_id, msg_type); + break; + default: + WARN_ONCE(1, "received unknown msg_type:%d\n", msg_type); + break; + } +} + +/** + * scmi_xfer_put() - Release a transmit message + * + * @handle: Pointer to SCMI entity handle + * @xfer: message that was reserved by scmi_xfer_get + */ +void scmi_xfer_put(const struct scmi_handle *handle, struct scmi_xfer *xfer) +{ + struct scmi_info *info = handle_to_scmi_info(handle); + + __scmi_xfer_put(&info->tx_minfo, xfer); +} + +#define SCMI_MAX_POLL_TO_NS (100 * NSEC_PER_USEC) + +static bool scmi_xfer_done_no_timeout(struct scmi_chan_info *cinfo, + struct scmi_xfer *xfer, ktime_t stop) +{ + struct scmi_info *info = handle_to_scmi_info(cinfo->handle); + + return info->desc->ops->poll_done(cinfo, xfer) || + ktime_after(ktime_get(), stop); +} + +/** + * scmi_do_xfer() - Do one transfer + * + * @handle: Pointer to SCMI entity handle + * @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. + */ +int scmi_do_xfer(const struct scmi_handle *handle, struct scmi_xfer *xfer) +{ + int ret; + int timeout; + struct scmi_info *info = handle_to_scmi_info(handle); + struct device *dev = info->dev; + struct scmi_chan_info *cinfo; + + cinfo = idr_find(&info->tx_idr, xfer->hdr.protocol_id); + if (unlikely(!cinfo)) + return -EINVAL; + + trace_scmi_xfer_begin(xfer->transfer_id, xfer->hdr.id, + xfer->hdr.protocol_id, xfer->hdr.seq, + xfer->hdr.poll_completion); + + ret = info->desc->ops->send_message(cinfo, xfer); + if (ret < 0) { + dev_dbg(dev, "Failed to send message %d\n", ret); + return ret; + } + + if (xfer->hdr.poll_completion) { + ktime_t stop = ktime_add_ns(ktime_get(), SCMI_MAX_POLL_TO_NS); + + spin_until_cond(scmi_xfer_done_no_timeout(cinfo, xfer, stop)); + + if (ktime_before(ktime_get(), stop)) + info->desc->ops->fetch_response(cinfo, xfer); + else + ret = -ETIMEDOUT; + } else { + /* 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, "timed out in resp(caller: %pS)\n", + (void *)_RET_IP_); + ret = -ETIMEDOUT; + } + } + + if (!ret && xfer->hdr.status) + ret = scmi_to_linux_errno(xfer->hdr.status); + + if (info->desc->ops->mark_txdone) + info->desc->ops->mark_txdone(cinfo, ret); + + trace_scmi_xfer_end(xfer->transfer_id, xfer->hdr.id, + xfer->hdr.protocol_id, xfer->hdr.seq, ret); + + return ret; +} + +void scmi_reset_rx_to_maxsz(const struct scmi_handle *handle, + struct scmi_xfer *xfer) +{ + struct scmi_info *info = handle_to_scmi_info(handle); + + xfer->rx.len = info->desc->max_msg_size; +} + +#define SCMI_MAX_RESPONSE_TIMEOUT (2 * MSEC_PER_SEC) + +/** + * scmi_do_xfer_with_response() - Do one transfer and wait until the delayed + * response is received + * + * @handle: Pointer to SCMI entity handle + * @xfer: Transfer to initiate and wait for response + * + * Return: -ETIMEDOUT in case of no delayed response, if transmit error, + * return corresponding error, else if all goes well, return 0. + */ +int scmi_do_xfer_with_response(const struct scmi_handle *handle, + struct scmi_xfer *xfer) +{ + int ret, timeout = msecs_to_jiffies(SCMI_MAX_RESPONSE_TIMEOUT); + DECLARE_COMPLETION_ONSTACK(async_response); + + xfer->async_done = &async_response; + + ret = scmi_do_xfer(handle, xfer); + if (!ret) { + if (!wait_for_completion_timeout(xfer->async_done, timeout)) + ret = -ETIMEDOUT; + else if (xfer->hdr.status) + ret = scmi_to_linux_errno(xfer->hdr.status); + } + + xfer->async_done = NULL; + return ret; +} + +/** + * scmi_xfer_get_init() - Allocate and initialise one message for transmit + * + * @handle: Pointer to SCMI entity handle + * @msg_id: Message identifier + * @prot_id: Protocol identifier for the message + * @tx_size: transmit message size + * @rx_size: receive message size + * @p: pointer to the allocated and initialised message + * + * This function allocates the message using @scmi_xfer_get and + * initialise the header. + * + * Return: 0 if all went fine with @p pointing to message, else + * corresponding error. + */ +int scmi_xfer_get_init(const struct scmi_handle *handle, u8 msg_id, u8 prot_id, + size_t tx_size, size_t rx_size, struct scmi_xfer **p) +{ + int ret; + struct scmi_xfer *xfer; + struct scmi_info *info = handle_to_scmi_info(handle); + struct scmi_xfers_info *minfo = &info->tx_minfo; + struct device *dev = info->dev; + + /* Ensure we have sane transfer sizes */ + if (rx_size > info->desc->max_msg_size || + tx_size > info->desc->max_msg_size) + return -ERANGE; + + xfer = scmi_xfer_get(handle, minfo); + if (IS_ERR(xfer)) { + ret = PTR_ERR(xfer); + dev_err(dev, "failed to get free message slot(%d)\n", ret); + return ret; + } + + xfer->tx.len = tx_size; + xfer->rx.len = rx_size ? : info->desc->max_msg_size; + xfer->hdr.id = msg_id; + xfer->hdr.protocol_id = prot_id; + xfer->hdr.poll_completion = false; + + *p = xfer; + + return 0; +} + +/** + * scmi_version_get() - command to get the revision of the SCMI entity + * + * @handle: Pointer to SCMI entity handle + * @protocol: Protocol identifier for the message + * @version: Holds returned version of protocol. + * + * Updates the SCMI information in the internal data structure. + * + * Return: 0 if all went fine, else return appropriate error. + */ +int scmi_version_get(const struct scmi_handle *handle, u8 protocol, + u32 *version) +{ + int ret; + __le32 *rev_info; + struct scmi_xfer *t; + + ret = scmi_xfer_get_init(handle, PROTOCOL_VERSION, protocol, 0, + sizeof(*version), &t); + if (ret) + return ret; + + ret = scmi_do_xfer(handle, t); + if (!ret) { + rev_info = t->rx.buf; + *version = le32_to_cpu(*rev_info); + } + + scmi_xfer_put(handle, t); + return ret; +} + +void scmi_setup_protocol_implemented(const struct scmi_handle *handle, + u8 *prot_imp) +{ + struct scmi_info *info = handle_to_scmi_info(handle); + + info->protocols_imp = prot_imp; +} + +static bool +scmi_is_protocol_implemented(const struct scmi_handle *handle, u8 prot_id) +{ + int i; + struct scmi_info *info = handle_to_scmi_info(handle); + + if (!info->protocols_imp) + return false; + + for (i = 0; i < MAX_PROTOCOLS_IMP; i++) + if (info->protocols_imp[i] == prot_id) + return true; + return false; +} + +/** + * scmi_handle_get() - Get the SCMI handle for a device + * + * @dev: pointer to device for which we want SCMI handle + * + * NOTE: The function does not track individual clients of the framework + * and is expected to be maintained by caller of SCMI protocol library. + * scmi_handle_put must be balanced with successful scmi_handle_get + * + * Return: pointer to handle if successful, NULL on error + */ +struct scmi_handle *scmi_handle_get(struct device *dev) +{ + struct list_head *p; + struct scmi_info *info; + struct scmi_handle *handle = NULL; + + mutex_lock(&scmi_list_mutex); + list_for_each(p, &scmi_list) { + info = list_entry(p, struct scmi_info, node); + if (dev->parent == info->dev) { + handle = &info->handle; + info->users++; + break; + } + } + mutex_unlock(&scmi_list_mutex); + + return handle; +} + +/** + * scmi_handle_put() - Release the handle acquired by scmi_handle_get + * + * @handle: handle acquired by scmi_handle_get + * + * NOTE: The function does not track individual clients of the framework + * and is expected to be maintained by caller of SCMI protocol library. + * scmi_handle_put must be balanced with successful scmi_handle_get + * + * Return: 0 is successfully released + * if null was passed, it returns -EINVAL; + */ +int scmi_handle_put(const struct scmi_handle *handle) +{ + struct scmi_info *info; + + if (!handle) + return -EINVAL; + + info = handle_to_scmi_info(handle); + mutex_lock(&scmi_list_mutex); + if (!WARN_ON(!info->users)) + info->users--; + mutex_unlock(&scmi_list_mutex); + + return 0; +} + +static int __scmi_xfer_info_init(struct scmi_info *sinfo, + struct scmi_xfers_info *info) +{ + int i; + struct scmi_xfer *xfer; + struct device *dev = sinfo->dev; + const struct scmi_desc *desc = sinfo->desc; + + /* Pre-allocated messages, no more than what hdr.seq can support */ + if (WARN_ON(!desc->max_msg || desc->max_msg > MSG_TOKEN_MAX)) { + dev_err(dev, + "Invalid maximum messages %d, not in range [1 - %lu]\n", + desc->max_msg, MSG_TOKEN_MAX); + return -EINVAL; + } + + info->xfer_block = devm_kcalloc(dev, desc->max_msg, + sizeof(*info->xfer_block), GFP_KERNEL); + if (!info->xfer_block) + return -ENOMEM; + + info->xfer_alloc_table = devm_kcalloc(dev, BITS_TO_LONGS(desc->max_msg), + sizeof(long), GFP_KERNEL); + if (!info->xfer_alloc_table) + return -ENOMEM; + + /* Pre-initialize the buffer pointer to pre-allocated buffers */ + for (i = 0, xfer = info->xfer_block; i < desc->max_msg; i++, xfer++) { + xfer->rx.buf = devm_kcalloc(dev, sizeof(u8), desc->max_msg_size, + GFP_KERNEL); + if (!xfer->rx.buf) + return -ENOMEM; + + xfer->tx.buf = xfer->rx.buf; + init_completion(&xfer->done); + } + + spin_lock_init(&info->xfer_lock); + + return 0; +} + +static int scmi_xfer_info_init(struct scmi_info *sinfo) +{ + int ret = __scmi_xfer_info_init(sinfo, &sinfo->tx_minfo); + + if (!ret && idr_find(&sinfo->rx_idr, SCMI_PROTOCOL_BASE)) + ret = __scmi_xfer_info_init(sinfo, &sinfo->rx_minfo); + + return ret; +} + +static int scmi_chan_setup(struct scmi_info *info, struct device *dev, + int prot_id, bool tx) +{ + int ret, idx; + struct scmi_chan_info *cinfo; + struct idr *idr; + + /* Transmit channel is first entry i.e. index 0 */ + idx = tx ? 0 : 1; + idr = tx ? &info->tx_idr : &info->rx_idr; + + /* check if already allocated, used for multiple device per protocol */ + cinfo = idr_find(idr, prot_id); + if (cinfo) + return 0; + + if (!info->desc->ops->chan_available(dev, idx)) { + cinfo = idr_find(idr, SCMI_PROTOCOL_BASE); + if (unlikely(!cinfo)) /* Possible only if platform has no Rx */ + return -EINVAL; + goto idr_alloc; + } + + cinfo = devm_kzalloc(info->dev, sizeof(*cinfo), GFP_KERNEL); + if (!cinfo) + return -ENOMEM; + + cinfo->dev = dev; + + ret = info->desc->ops->chan_setup(cinfo, info->dev, tx); + if (ret) + return ret; + +idr_alloc: + ret = idr_alloc(idr, cinfo, prot_id, prot_id + 1, GFP_KERNEL); + if (ret != prot_id) { + dev_err(dev, "unable to allocate SCMI idr slot err %d\n", ret); + return ret; + } + + cinfo->handle = &info->handle; + return 0; +} + +static inline int +scmi_txrx_setup(struct scmi_info *info, struct device *dev, int prot_id) +{ + int ret = scmi_chan_setup(info, dev, prot_id, true); + + if (!ret) { + /* Rx is optional, report only memory errors */ + ret = scmi_chan_setup(info, dev, prot_id, false); + if (ret && ret != -ENOMEM) + ret = 0; + } + + return ret; +} + +static inline void +scmi_create_protocol_device(struct device_node *np, struct scmi_info *info, + int prot_id, const char *name) +{ + struct scmi_device *sdev; + + sdev = scmi_device_create(np, info->dev, prot_id, name); + if (!sdev) { + dev_err(info->dev, "failed to create %d protocol device\n", + prot_id); + return; + } + + if (scmi_txrx_setup(info, &sdev->dev, prot_id)) { + dev_err(&sdev->dev, "failed to setup transport\n"); + scmi_device_destroy(sdev); + return; + } + + /* setup handle now as the transport is ready */ + scmi_set_handle(sdev); +} + +#define MAX_SCMI_DEV_PER_PROTOCOL 2 +struct scmi_prot_devnames { + int protocol_id; + char *names[MAX_SCMI_DEV_PER_PROTOCOL]; +}; + +static struct scmi_prot_devnames devnames[] = { + { SCMI_PROTOCOL_POWER, { "genpd" },}, + { SCMI_PROTOCOL_SYSTEM, { "syspower" },}, + { SCMI_PROTOCOL_PERF, { "cpufreq" },}, + { SCMI_PROTOCOL_CLOCK, { "clocks" },}, + { SCMI_PROTOCOL_SENSOR, { "hwmon" },}, + { SCMI_PROTOCOL_RESET, { "reset" },}, +}; + +static inline void +scmi_create_protocol_devices(struct device_node *np, struct scmi_info *info, + int prot_id) +{ + int loop, cnt; + + for (loop = 0; loop < ARRAY_SIZE(devnames); loop++) { + if (devnames[loop].protocol_id != prot_id) + continue; + + for (cnt = 0; cnt < ARRAY_SIZE(devnames[loop].names); cnt++) { + const char *name = devnames[loop].names[cnt]; + + if (name) + scmi_create_protocol_device(np, info, prot_id, + name); + } + } +} + +static int scmi_probe(struct platform_device *pdev) +{ + int ret; + struct scmi_handle *handle; + const struct scmi_desc *desc; + struct scmi_info *info; + struct device *dev = &pdev->dev; + struct device_node *child, *np = dev->of_node; + + desc = of_device_get_match_data(dev); + if (!desc) + return -EINVAL; + + info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL); + if (!info) + return -ENOMEM; + + info->dev = dev; + info->desc = desc; + INIT_LIST_HEAD(&info->node); + + platform_set_drvdata(pdev, info); + idr_init(&info->tx_idr); + idr_init(&info->rx_idr); + + handle = &info->handle; + handle->dev = info->dev; + handle->version = &info->version; + + ret = scmi_txrx_setup(info, dev, SCMI_PROTOCOL_BASE); + if (ret) + return ret; + + ret = scmi_xfer_info_init(info); + if (ret) + return ret; + + if (scmi_notification_init(handle)) + dev_err(dev, "SCMI Notifications NOT available.\n"); + + ret = scmi_base_protocol_init(handle); + if (ret) { + dev_err(dev, "unable to communicate with SCMI(%d)\n", ret); + return ret; + } + + mutex_lock(&scmi_list_mutex); + list_add_tail(&info->node, &scmi_list); + mutex_unlock(&scmi_list_mutex); + + for_each_available_child_of_node(np, child) { + u32 prot_id; + + if (of_property_read_u32(child, "reg", &prot_id)) + continue; + + if (!FIELD_FIT(MSG_PROTOCOL_ID_MASK, prot_id)) + dev_err(dev, "Out of range protocol %d\n", prot_id); + + if (!scmi_is_protocol_implemented(handle, prot_id)) { + dev_err(dev, "SCMI protocol %d not implemented\n", + prot_id); + continue; + } + + scmi_create_protocol_devices(child, info, prot_id); + } + + return 0; +} + +void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id) +{ + idr_remove(idr, id); +} + +static int scmi_remove(struct platform_device *pdev) +{ + int ret = 0; + struct scmi_info *info = platform_get_drvdata(pdev); + struct idr *idr = &info->tx_idr; + + mutex_lock(&scmi_list_mutex); + if (info->users) + ret = -EBUSY; + else + list_del(&info->node); + mutex_unlock(&scmi_list_mutex); + + if (ret) + return ret; + + scmi_notification_exit(&info->handle); + + /* Safe to free channels since no more users */ + ret = idr_for_each(idr, info->desc->ops->chan_free, idr); + idr_destroy(&info->tx_idr); + + idr = &info->rx_idr; + ret = idr_for_each(idr, info->desc->ops->chan_free, idr); + idr_destroy(&info->rx_idr); + + return ret; +} + +static ssize_t protocol_version_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct scmi_info *info = dev_get_drvdata(dev); + + return sprintf(buf, "%u.%u\n", info->version.major_ver, + info->version.minor_ver); +} +static DEVICE_ATTR_RO(protocol_version); + +static ssize_t firmware_version_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct scmi_info *info = dev_get_drvdata(dev); + + return sprintf(buf, "0x%x\n", info->version.impl_ver); +} +static DEVICE_ATTR_RO(firmware_version); + +static ssize_t vendor_id_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct scmi_info *info = dev_get_drvdata(dev); + + return sprintf(buf, "%s\n", info->version.vendor_id); +} +static DEVICE_ATTR_RO(vendor_id); + +static ssize_t sub_vendor_id_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct scmi_info *info = dev_get_drvdata(dev); + + return sprintf(buf, "%s\n", info->version.sub_vendor_id); +} +static DEVICE_ATTR_RO(sub_vendor_id); + +static struct attribute *versions_attrs[] = { + &dev_attr_firmware_version.attr, + &dev_attr_protocol_version.attr, + &dev_attr_vendor_id.attr, + &dev_attr_sub_vendor_id.attr, + NULL, +}; +ATTRIBUTE_GROUPS(versions); + +/* Each compatible listed below must have descriptor associated with it */ +static const struct of_device_id scmi_of_match[] = { +#ifdef CONFIG_MAILBOX + { .compatible = "arm,scmi", .data = &scmi_mailbox_desc }, +#endif +#ifdef CONFIG_HAVE_ARM_SMCCC_DISCOVERY + { .compatible = "arm,scmi-smc", .data = &scmi_smc_desc}, +#endif + { /* Sentinel */ }, +}; + +MODULE_DEVICE_TABLE(of, scmi_of_match); + +static struct platform_driver scmi_driver = { + .driver = { + .name = "arm-scmi", + .suppress_bind_attrs = true, + .of_match_table = scmi_of_match, + .dev_groups = versions_groups, + }, + .probe = scmi_probe, + .remove = scmi_remove, +}; + +static int __init scmi_driver_init(void) +{ + scmi_bus_init(); + + scmi_clock_register(); + scmi_perf_register(); + scmi_power_register(); + scmi_reset_register(); + scmi_sensors_register(); + scmi_system_register(); + + return platform_driver_register(&scmi_driver); +} +subsys_initcall(scmi_driver_init); + +static void __exit scmi_driver_exit(void) +{ + scmi_bus_exit(); + + scmi_clock_unregister(); + scmi_perf_unregister(); + scmi_power_unregister(); + scmi_reset_unregister(); + scmi_sensors_unregister(); + scmi_system_unregister(); + + platform_driver_unregister(&scmi_driver); +} +module_exit(scmi_driver_exit); + +MODULE_ALIAS("platform:arm-scmi"); +MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>"); +MODULE_DESCRIPTION("ARM SCMI protocol driver"); +MODULE_LICENSE("GPL v2"); |