// SPDX-License-Identifier: GPL-2.0
/*
 * Texas Instruments System Control Interface Protocol Driver
 *
 * Copyright (C) 2015-2016 Texas Instruments Incorporated - http://www.ti.com/
 *      Nishanth Menon
 */

#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 <linux/reboot.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
 * @nb: Reboot Notifier block
 * @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;
        struct notifier_block nb;
        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)
#define reboot_to_ti_sci_info(n) container_of(n, struct ti_sci_info, nb)

#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) -
                                              sizeof("ti_sci_debug@")),
                                      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 %zu 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 %zu < 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: %pS)\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_is_response_ack() - Generic ACK/NACK message checkup
 * @r:  pointer to response buffer
 *
 * Return: true if the response was an ACK, else returns false.
 */
static inline bool ti_sci_is_response_ack(void *r)
{
        struct ti_sci_msg_hdr *hdr = r;

        return hdr->flags & TI_SCI_FLAG_RESP_GENERIC_ACK ? true : false;
}

/**
 * ti_sci_set_device_state() - Set device state helper
 * @handle:     pointer to TI SCI handle
 * @id:         Device identifier
 * @flags:      flags to setup for the device
 * @state:      State to move the device to
 *
 * Return: 0 if all went well, else returns appropriate error value.
 */
static int ti_sci_set_device_state(const struct ti_sci_handle *handle,
                                   u32 id, u32 flags, u8 state)
{
        struct ti_sci_info *info;
        struct ti_sci_msg_req_set_device_state *req;
        struct ti_sci_msg_hdr *resp;
        struct ti_sci_xfer *xfer;
        struct device *dev;
        int ret = 0;

        if (IS_ERR(handle))
                return PTR_ERR(handle);
        if (!handle)
                return -EINVAL;

        info = handle_to_ti_sci_info(handle);
        dev = info->dev;

        xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_SET_DEVICE_STATE,
                                   flags | TI_SCI_FLAG_REQ_ACK_ON_PROCESSED,
                                   sizeof(*req), sizeof(*resp));
        if (IS_ERR(xfer)) {
                ret = PTR_ERR(xfer);
                dev_err(dev, "Message alloc failed(%d)\n", ret);
                return ret;
        }
        req = (struct ti_sci_msg_req_set_device_state *)xfer->xfer_buf;
        req->id = id;
        req->state = state;

        ret = ti_sci_do_xfer(info, xfer);
        if (ret) {
                dev_err(dev, "Mbox send fail %d\n", ret);
                goto fail;
        }

        resp = (struct ti_sci_msg_hdr *)xfer->xfer_buf;

        ret = ti_sci_is_response_ack(resp) ? 0 : -ENODEV;

fail:
        ti_sci_put_one_xfer(&info->minfo, xfer);

        return ret;
}

/**
 * ti_sci_get_device_state() - Get device state helper
 * @handle:     Handle to the device
 * @id:         Device Identifier
 * @clcnt:      Pointer to Context Loss Count
 * @resets:     pointer to resets
 * @p_state:    pointer to p_state
 * @c_state:    pointer to c_state
 *
 * Return: 0 if all went fine, else return appropriate error.
 */
static int ti_sci_get_device_state(const struct ti_sci_handle *handle,
                                   u32 id,  u32 *clcnt,  u32 *resets,
                                    u8 *p_state,  u8 *c_state)
{
        struct ti_sci_info *info;
        struct ti_sci_msg_req_get_device_state *req;
        struct ti_sci_msg_resp_get_device_state *resp;
        struct ti_sci_xfer *xfer;
        struct device *dev;
        int ret = 0;

        if (IS_ERR(handle))
                return PTR_ERR(handle);
        if (!handle)
                return -EINVAL;

        if (!clcnt && !resets && !p_state && !c_state)
                return -EINVAL;

        info = handle_to_ti_sci_info(handle);
        dev = info->dev;

        /* Response is expected, so need of any flags */
        xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_GET_DEVICE_STATE,
                                   0, sizeof(*req), sizeof(*resp));
        if (IS_ERR(xfer)) {
                ret = PTR_ERR(xfer);
                dev_err(dev, "Message alloc failed(%d)\n", ret);
                return ret;
        }
        req = (struct ti_sci_msg_req_get_device_state *)xfer->xfer_buf;
        req->id = id;

        ret = ti_sci_do_xfer(info, xfer);
        if (ret) {
                dev_err(dev, "Mbox send fail %d\n", ret);
                goto fail;
        }

        resp = (struct ti_sci_msg_resp_get_device_state *)xfer->xfer_buf;
        if (!ti_sci_is_response_ack(resp)) {
                ret = -ENODEV;
                goto fail;
        }

        if (clcnt)
                *clcnt = resp->context_loss_count;
        if (resets)
                *resets = resp->resets;
        if (p_state)
                *p_state = resp->programmed_state;
        if (c_state)
                *c_state = resp->current_state;
fail:
        ti_sci_put_one_xfer(&info->minfo, xfer);

        return ret;
}

/**
 * ti_sci_cmd_get_device() - command to request for device managed by TISCI
 * @handle:     Pointer to TISCI handle as retrieved by *ti_sci_get_handle
 * @id:         Device Identifier
 *
 * Request for the device - NOTE: the client MUST maintain integrity of
 * usage count by balancing get_device with put_device. No refcounting is
 * managed by driver for that purpose.
 *
 * NOTE: The request is for exclusive access for the processor.
 *
 * Return: 0 if all went fine, else return appropriate error.
 */
static int ti_sci_cmd_get_device(const struct ti_sci_handle *handle, u32 id)
{
        return ti_sci_set_device_state(handle, id,
                                       MSG_FLAG_DEVICE_EXCLUSIVE,
                                       MSG_DEVICE_SW_STATE_ON);
}

/**
 * ti_sci_cmd_idle_device() - Command to idle a device managed by TISCI
 * @handle:     Pointer to TISCI handle as retrieved by *ti_sci_get_handle
 * @id:         Device Identifier
 *
 * Request for the device - NOTE: the client MUST maintain integrity of
 * usage count by balancing get_device with put_device. No refcounting is
 * managed by driver for that purpose.
 *
 * Return: 0 if all went fine, else return appropriate error.
 */
static int ti_sci_cmd_idle_device(const struct ti_sci_handle *handle, u32 id)
{
        return ti_sci_set_device_state(handle, id,
                                       MSG_FLAG_DEVICE_EXCLUSIVE,
                                       MSG_DEVICE_SW_STATE_RETENTION);
}

/**
 * ti_sci_cmd_put_device() - command to release a device managed by TISCI
 * @handle:     Pointer to TISCI handle as retrieved by *ti_sci_get_handle
 * @id:         Device Identifier
 *
 * Request for the device - NOTE: the client MUST maintain integrity of
 * usage count by balancing get_device with put_device. No refcounting is
 * managed by driver for that purpose.
 *
 * Return: 0 if all went fine, else return appropriate error.
 */
static int ti_sci_cmd_put_device(const struct ti_sci_handle *handle, u32 id)
{
        return ti_sci_set_device_state(handle, id,
                                       0, MSG_DEVICE_SW_STATE_AUTO_OFF);
}

/**
 * ti_sci_cmd_dev_is_valid() - Is the device valid
 * @handle:     Pointer to TISCI handle as retrieved by *ti_sci_get_handle
 * @id:         Device Identifier
 *
 * Return: 0 if all went fine and the device ID is valid, else return
 * appropriate error.
 */
static int ti_sci_cmd_dev_is_valid(const struct ti_sci_handle *handle, u32 id)
{
        u8 unused;

        /* check the device state which will also tell us if the ID is valid */
        return ti_sci_get_device_state(handle, id, NULL, NULL, NULL, &unused);
}

/**
 * ti_sci_cmd_dev_get_clcnt() - Get context loss counter
 * @handle:     Pointer to TISCI handle
 * @id:         Device Identifier
 * @count:      Pointer to Context Loss counter to populate
 *
 * Return: 0 if all went fine, else return appropriate error.
 */
static int ti_sci_cmd_dev_get_clcnt(const struct ti_sci_handle *handle, u32 id,
                                    u32 *count)
{
        return ti_sci_get_device_state(handle, id, count, NULL, NULL, NULL);
}

/**
 * ti_sci_cmd_dev_is_idle() - Check if the device is requested to be idle
 * @handle:     Pointer to TISCI handle
 * @id:         Device Identifier
 * @r_state:    true if requested to be idle
 *
 * Return: 0 if all went fine, else return appropriate error.
 */
static int ti_sci_cmd_dev_is_idle(const struct ti_sci_handle *handle, u32 id,
                                  bool *r_state)
{
        int ret;
        u8 state;

        if (!r_state)
                return -EINVAL;

        ret = ti_sci_get_device_state(handle, id, NULL, NULL, &state, NULL);
        if (ret)
                return ret;

        *r_state = (state == MSG_DEVICE_SW_STATE_RETENTION);

        return 0;
}

/**
 * ti_sci_cmd_dev_is_stop() - Check if the device is requested to be stopped
 * @handle:     Pointer to TISCI handle
 * @id:         Device Identifier
 * @r_state:    true if requested to be stopped
 * @curr_state: true if currently stopped.
 *
 * Return: 0 if all went fine, else return appropriate error.
 */
static int ti_sci_cmd_dev_is_stop(const struct ti_sci_handle *handle, u32 id,
                                  bool *r_state,  bool *curr_state)
{
        int ret;
        u8 p_state, c_state;

        if (!r_state && !curr_state)
                return -EINVAL;

        ret =
            ti_sci_get_device_state(handle, id, NULL, NULL, &p_state, &c_state);
        if (ret)
                return ret;

        if (r_state)
                *r_state = (p_state == MSG_DEVICE_SW_STATE_AUTO_OFF);
        if (curr_state)
                *curr_state = (c_state == MSG_DEVICE_HW_STATE_OFF);

        return 0;
}

/**
 * ti_sci_cmd_dev_is_on() - Check if the device is requested to be ON
 * @handle:     Pointer to TISCI handle
 * @id:         Device Identifier
 * @r_state:    true if requested to be ON
 * @curr_state: true if currently ON and active
 *
 * Return: 0 if all went fine, else return appropriate error.
 */
static int ti_sci_cmd_dev_is_on(const struct ti_sci_handle *handle, u32 id,
                                bool *r_state,  bool *curr_state)
{
        int ret;
        u8 p_state, c_state;

        if (!r_state && !curr_state)
                return -EINVAL;

        ret =
            ti_sci_get_device_state(handle, id, NULL, NULL, &p_state, &c_state);
        if (ret)
                return ret;

        if (r_state)
                *r_state = (p_state == MSG_DEVICE_SW_STATE_ON);
        if (curr_state)
                *curr_state = (c_state == MSG_DEVICE_HW_STATE_ON);

        return 0;
}

/**
 * ti_sci_cmd_dev_is_trans() - Check if the device is currently transitioning
 * @handle:     Pointer to TISCI handle
 * @id:         Device Identifier
 * @curr_state: true if currently transitioning.
 *
 * Return: 0 if all went fine, else return appropriate error.
 */
static int ti_sci_cmd_dev_is_trans(const struct ti_sci_handle *handle, u32 id,
                                   bool *curr_state)
{
        int ret;
        u8 state;

        if (!curr_state)
                return -EINVAL;

        ret = ti_sci_get_device_state(handle, id, NULL, NULL, NULL, &state);
        if (ret)
                return ret;

        *curr_state = (state == MSG_DEVICE_HW_STATE_TRANS);

        return 0;
}

/**
 * ti_sci_cmd_set_device_resets() - command to set resets for device managed
 *                                  by TISCI
 * @handle:     Pointer to TISCI handle as retrieved by *ti_sci_get_handle
 * @id:         Device Identifier
 * @reset_state: Device specific reset bit field
 *
 * Return: 0 if all went fine, else return appropriate error.
 */
static int ti_sci_cmd_set_device_resets(const struct ti_sci_handle *handle,
                                        u32 id, u32 reset_state)
{
        struct ti_sci_info *info;
        struct ti_sci_msg_req_set_device_resets *req;
        struct ti_sci_msg_hdr *resp;
        struct ti_sci_xfer *xfer;
        struct device *dev;
        int ret = 0;

        if (IS_ERR(handle))
                return PTR_ERR(handle);
        if (!handle)
                return -EINVAL;

        info = handle_to_ti_sci_info(handle);
        dev = info->dev;

        xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_SET_DEVICE_RESETS,
                                   TI_SCI_FLAG_REQ_ACK_ON_PROCESSED,
                                   sizeof(*req), sizeof(*resp));
        if (IS_ERR(xfer)) {
                ret = PTR_ERR(xfer);
                dev_err(dev, "Message alloc failed(%d)\n", ret);
                return ret;
        }
        req = (struct ti_sci_msg_req_set_device_resets *)xfer->xfer_buf;
        req->id = id;
        req->resets = reset_state;

        ret = ti_sci_do_xfer(info, xfer);
        if (ret) {
                dev_err(dev, "Mbox send fail %d\n", ret);
                goto fail;
        }

        resp = (struct ti_sci_msg_hdr *)xfer->xfer_buf;

        ret = ti_sci_is_response_ack(resp) ? 0 : -ENODEV;

fail:
        ti_sci_put_one_xfer(&info->minfo, xfer);

        return ret;
}

/**
 * ti_sci_cmd_get_device_resets() - Get reset state for device managed
 *                                  by TISCI
 * @handle:             Pointer to TISCI handle
 * @id:                 Device Identifier
 * @reset_state:        Pointer to reset state to populate
 *
 * Return: 0 if all went fine, else return appropriate error.
 */
static int ti_sci_cmd_get_device_resets(const struct ti_sci_handle *handle,
                                        u32 id, u32 *reset_state)
{
        return ti_sci_get_device_state(handle, id, NULL, reset_state, NULL,
                                       NULL);
}

/**
 * ti_sci_set_clock_state() - Set clock state helper
 * @handle:     pointer to TI SCI handle
 * @dev_id:     Device identifier this request is for
 * @clk_id:     Clock identifier for the device for this request.
 *              Each device has it's own set of clock inputs. This indexes
 *              which clock input to modify.
 * @flags:      Header flags as needed
 * @state:      State to request for the clock.
 *
 * Return: 0 if all went well, else returns appropriate error value.
 */
static int ti_sci_set_clock_state(const struct ti_sci_handle *handle,
                                  u32 dev_id, u8 clk_id,
                                  u32 flags, u8 state)
{
        struct ti_sci_info *info;
        struct ti_sci_msg_req_set_clock_state *req;
        struct ti_sci_msg_hdr *resp;
        struct ti_sci_xfer *xfer;
        struct device *dev;
        int ret = 0;

        if (IS_ERR(handle))
                return PTR_ERR(handle);
        if (!handle)
                return -EINVAL;

        info = handle_to_ti_sci_info(handle);
        dev = info->dev;

        xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_SET_CLOCK_STATE,
                                   flags | TI_SCI_FLAG_REQ_ACK_ON_PROCESSED,
                                   sizeof(*req), sizeof(*resp));
        if (IS_ERR(xfer)) {
                ret = PTR_ERR(xfer);
                dev_err(dev, "Message alloc failed(%d)\n", ret);
                return ret;
        }
        req = (struct ti_sci_msg_req_set_clock_state *)xfer->xfer_buf;
        req->dev_id = dev_id;
        req->clk_id = clk_id;
        req->request_state = state;

        ret = ti_sci_do_xfer(info, xfer);
        if (ret) {
                dev_err(dev, "Mbox send fail %d\n", ret);
                goto fail;
        }

        resp = (struct ti_sci_msg_hdr *)xfer->xfer_buf;

        ret = ti_sci_is_response_ack(resp) ? 0 : -ENODEV;

fail:
        ti_sci_put_one_xfer(&info->minfo, xfer);

        return ret;
}

/**
 * ti_sci_cmd_get_clock_state() - Get clock state helper
 * @handle:     pointer to TI SCI handle
 * @dev_id:     Device identifier this request is for
 * @clk_id:     Clock identifier for the device for this request.
 *              Each device has it's own set of clock inputs. This indexes
 *              which clock input to modify.
 * @programmed_state:   State requested for clock to move to
 * @current_state:      State that the clock is currently in
 *
 * Return: 0 if all went well, else returns appropriate error value.
 */
static int ti_sci_cmd_get_clock_state(const struct ti_sci_handle *handle,
                                      u32 dev_id, u8 clk_id,
                                      u8 *programmed_state, u8 *current_state)
{
        struct ti_sci_info *info;
        struct ti_sci_msg_req_get_clock_state *req;
        struct ti_sci_msg_resp_get_clock_state *resp;
        struct ti_sci_xfer *xfer;
        struct device *dev;
        int ret = 0;

        if (IS_ERR(handle))
                return PTR_ERR(handle);
        if (!handle)
                return -EINVAL;

        if (!programmed_state && !current_state)
                return -EINVAL;

        info = handle_to_ti_sci_info(handle);
        dev = info->dev;

        xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_GET_CLOCK_STATE,
                                   TI_SCI_FLAG_REQ_ACK_ON_PROCESSED,
                                   sizeof(*req), sizeof(*resp));
        if (IS_ERR(xfer)) {

                ret = PTR_ERR(xfer);
                dev_err(dev, "Message alloc failed(%d)\n", ret);
                return ret;
        }
        req = (struct ti_sci_msg_req_get_clock_state *)xfer->xfer_buf;
        req->dev_id = dev_id;
        req->clk_id = clk_id;

        ret = ti_sci_do_xfer(info, xfer);
        if (ret) {
                dev_err(dev, "Mbox send fail %d\n", ret);
                goto fail;
        }

        resp = (struct ti_sci_msg_resp_get_clock_state *)xfer->xfer_buf;

        if (!ti_sci_is_response_ack(resp)) {
                ret = -ENODEV;
                goto fail;
        }

        if (programmed_state)
                *programmed_state = resp->programmed_state;
        if (current_state)
                *current_state = resp->current_state;

fail:
        ti_sci_put_one_xfer(&info->minfo, xfer);

        return ret;
}

/**
 * ti_sci_cmd_get_clock() - Get control of a clock from TI SCI
 * @handle:     pointer to TI SCI handle
 * @dev_id:     Device identifier this request is for
 * @clk_id:     Clock identifier for the device for this request.
 *              Each device has it's own set of clock inputs. This indexes
 *              which clock input to modify.
 * @needs_ssc: 'true' if Spread Spectrum clock is desired, else 'false'
 * @can_change_freq: 'true' if frequency change is desired, else 'false'
 * @enable_input_term: 'true' if input termination is desired, else 'false'
 *
 * Return: 0 if all went well, else returns appropriate error value.
 */
static int ti_sci_cmd_get_clock(const struct ti_sci_handle *handle, u32 dev_id,
                                u8 clk_id, bool needs_ssc, bool can_change_freq,
                                bool enable_input_term)
{
        u32 flags = 0;

        flags |= needs_ssc ? MSG_FLAG_CLOCK_ALLOW_SSC : 0;
        flags |= can_change_freq ? MSG_FLAG_CLOCK_ALLOW_FREQ_CHANGE : 0;
        flags |= enable_input_term ? MSG_FLAG_CLOCK_INPUT_TERM : 0;

        return ti_sci_set_clock_state(handle, dev_id, clk_id, flags,
                                      MSG_CLOCK_SW_STATE_REQ);
}

/**
 * ti_sci_cmd_idle_clock() - Idle a clock which is in our control
 * @handle:     pointer to TI SCI handle
 * @dev_id:     Device identifier this request is for
 * @clk_id:     Clock identifier for the device for this request.
 *              Each device has it's own set of clock inputs. This indexes
 *              which clock input to modify.
 *
 * NOTE: This clock must have been requested by get_clock previously.
 *
 * Return: 0 if all went well, else returns appropriate error value.
 */
static int ti_sci_cmd_idle_clock(const struct ti_sci_handle *handle,
                                 u32 dev_id, u8 clk_id)
{
        return ti_sci_set_clock_state(handle, dev_id, clk_id, 0,
                                      MSG_CLOCK_SW_STATE_UNREQ);
}

/**
 * ti_sci_cmd_put_clock() - Release a clock from our control back to TISCI
 * @handle:     pointer to TI SCI handle
 * @dev_id:     Device identifier this request is for
 * @clk_id:     Clock identifier for the device for this request.
 *              Each device has it's own set of clock inputs. This indexes
 *              which clock input to modify.
 *
 * NOTE: This clock must have been requested by get_clock previously.
 *
 * Return: 0 if all went well, else returns appropriate error value.
 */
static int ti_sci_cmd_put_clock(const struct ti_sci_handle *handle,
                                u32 dev_id, u8 clk_id)
{
        return ti_sci_set_clock_state(handle, dev_id, clk_id, 0,
                                      MSG_CLOCK_SW_STATE_AUTO);
}

/**
 * ti_sci_cmd_clk_is_auto() - Is the clock being auto managed
 * @handle:     pointer to TI SCI handle
 * @dev_id:     Device identifier this request is for
 * @clk_id:     Clock identifier for the device for this request.
 *              Each device has it's own set of clock inputs. This indexes
 *              which clock input to modify.
 * @req_state: state indicating if the clock is auto managed
 *
 * Return: 0 if all went well, else returns appropriate error value.
 */
static int ti_sci_cmd_clk_is_auto(const struct ti_sci_handle *handle,
                                  u32 dev_id, u8 clk_id, bool *req_state)
{
        u8 state = 0;
        int ret;

        if (!req_state)
                return -EINVAL;

        ret = ti_sci_cmd_get_clock_state(handle, dev_id, clk_id, &state, NULL);
        if (ret)
                return ret;

        *req_state = (state == MSG_CLOCK_SW_STATE_AUTO);
        return 0;
}

/**
 * ti_sci_cmd_clk_is_on() - Is the clock ON
 * @handle:     pointer to TI SCI handle
 * @dev_id:     Device identifier this request is for
 * @clk_id:     Clock identifier for the device for this request.
 *              Each device has it's own set of clock inputs. This indexes
 *              which clock input to modify.
 * @req_state: state indicating if the clock is managed by us and enabled
 * @curr_state: state indicating if the clock is ready for operation
 *
 * Return: 0 if all went well, else returns appropriate error value.
 */
static int ti_sci_cmd_clk_is_on(const struct ti_sci_handle *handle, u32 dev_id,
                                u8 clk_id, bool *req_state, bool *curr_state)
{
        u8 c_state = 0, r_state = 0;
        int ret;

        if (!req_state && !curr_state)
                return -EINVAL;

        ret = ti_sci_cmd_get_clock_state(handle, dev_id, clk_id,
                                         &r_state, &c_state);
        if (ret)
                return ret;

        if (req_state)
                *req_state = (r_state == MSG_CLOCK_SW_STATE_REQ);
        if (curr_state)
                *curr_state = (c_state == MSG_CLOCK_HW_STATE_READY);
        return 0;
}

/**
 * ti_sci_cmd_clk_is_off() - Is the clock OFF
 * @handle:     pointer to TI SCI handle
 * @dev_id:     Device identifier this request is for
 * @clk_id:     Clock identifier for the device for this request.
 *              Each device has it's own set of clock inputs. This indexes
 *              which clock input to modify.
 * @req_state: state indicating if the clock is managed by us and disabled
 * @curr_state: state indicating if the clock is NOT ready for operation
 *
 * Return: 0 if all went well, else returns appropriate error value.
 */
static int ti_sci_cmd_clk_is_off(const struct ti_sci_handle *handle, u32 dev_id,
                                 u8 clk_id, bool *req_state, bool *curr_state)
{
        u8 c_state = 0, r_state = 0;
        int ret;

        if (!req_state && !curr_state)
                return -EINVAL;

        ret = ti_sci_cmd_get_clock_state(handle, dev_id, clk_id,
                                         &r_state, &c_state);
        if (ret)
                return ret;

        if (req_state)
                *req_state = (r_state == MSG_CLOCK_SW_STATE_UNREQ);
        if (curr_state)
                *curr_state = (c_state == MSG_CLOCK_HW_STATE_NOT_READY);
        return 0;
}

/**
 * ti_sci_cmd_clk_set_parent() - Set the clock source of a specific device clock
 * @handle:     pointer to TI SCI handle
 * @dev_id:     Device identifier this request is for
 * @clk_id:     Clock identifier for the device for this request.
 *              Each device has it's own set of clock inputs. This indexes
 *              which clock input to modify.
 * @parent_id:  Parent clock identifier to set
 *
 * Return: 0 if all went well, else returns appropriate error value.
 */
static int ti_sci_cmd_clk_set_parent(const struct ti_sci_handle *handle,
                                     u32 dev_id, u8 clk_id, u8 parent_id)
{
        struct ti_sci_info *info;
        struct ti_sci_msg_req_set_clock_parent *req;
        struct ti_sci_msg_hdr *resp;
        struct ti_sci_xfer *xfer;
        struct device *dev;
        int ret = 0;

        if (IS_ERR(handle))
                return PTR_ERR(handle);
        if (!handle)
                return -EINVAL;

        info = handle_to_ti_sci_info(handle);
        dev = info->dev;

        xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_SET_CLOCK_PARENT,
                                   TI_SCI_FLAG_REQ_ACK_ON_PROCESSED,
                                   sizeof(*req), sizeof(*resp));
        if (IS_ERR(xfer)) {
                ret = PTR_ERR(xfer);
                dev_err(dev, "Message alloc failed(%d)\n", ret);
                return ret;
        }
        req = (struct ti_sci_msg_req_set_clock_parent *)xfer->xfer_buf;
        req->dev_id = dev_id;
        req->clk_id = clk_id;
        req->parent_id = parent_id;

        ret = ti_sci_do_xfer(info, xfer);
        if (ret) {
                dev_err(dev, "Mbox send fail %d\n", ret);
                goto fail;
        }

        resp = (struct ti_sci_msg_hdr *)xfer->xfer_buf;

        ret = ti_sci_is_response_ack(resp) ? 0 : -ENODEV;

fail:
        ti_sci_put_one_xfer(&info->minfo, xfer);

        return ret;
}

/**
 * ti_sci_cmd_clk_get_parent() - Get current parent clock source
 * @handle:     pointer to TI SCI handle
 * @dev_id:     Device identifier this request is for
 * @clk_id:     Clock identifier for the device for this request.
 *              Each device has it's own set of clock inputs. This indexes
 *              which clock input to modify.
 * @parent_id:  Current clock parent
 *
 * Return: 0 if all went well, else returns appropriate error value.
 */
static int ti_sci_cmd_clk_get_parent(const struct ti_sci_handle *handle,
                                     u32 dev_id, u8 clk_id, u8 *parent_id)
{
        struct ti_sci_info *info;
        struct ti_sci_msg_req_get_clock_parent *req;
        struct ti_sci_msg_resp_get_clock_parent *resp;
        struct ti_sci_xfer *xfer;
        struct device *dev;
        int ret = 0;

        if (IS_ERR(handle))
                return PTR_ERR(handle);
        if (!handle || !parent_id)
                return -EINVAL;

        info = handle_to_ti_sci_info(handle);
        dev = info->dev;

        xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_GET_CLOCK_PARENT,
                                   TI_SCI_FLAG_REQ_ACK_ON_PROCESSED,
                                   sizeof(*req), sizeof(*resp));
        if (IS_ERR(xfer)) {
                ret = PTR_ERR(xfer);
                dev_err(dev, "Message alloc failed(%d)\n", ret);
                return ret;
        }
        req = (struct ti_sci_msg_req_get_clock_parent *)xfer->xfer_buf;
        req->dev_id = dev_id;
        req->clk_id = clk_id;

        ret = ti_sci_do_xfer(info, xfer);
        if (ret) {
                dev_err(dev, "Mbox send fail %d\n", ret);
                goto fail;
        }

        resp = (struct ti_sci_msg_resp_get_clock_parent *)xfer->xfer_buf;

        if (!ti_sci_is_response_ack(resp))
                ret = -ENODEV;
        else
                *parent_id = resp->parent_id;

fail:
        ti_sci_put_one_xfer(&info->minfo, xfer);

        return ret;
}

/**
 * ti_sci_cmd_clk_get_num_parents() - Get num parents of the current clk source
 * @handle:     pointer to TI SCI handle
 * @dev_id:     Device identifier this request is for
 * @clk_id:     Clock identifier for the device for this request.
 *              Each device has it's own set of clock inputs. This indexes
 *              which clock input to modify.
 * @num_parents: Returns he number of parents to the current clock.
 *
 * Return: 0 if all went well, else returns appropriate error value.
 */
static int ti_sci_cmd_clk_get_num_parents(const struct ti_sci_handle *handle,
                                          u32 dev_id, u8 clk_id,
                                          u8 *num_parents)
{
        struct ti_sci_info *info;
        struct ti_sci_msg_req_get_clock_num_parents *req;
        struct ti_sci_msg_resp_get_clock_num_parents *resp;
        struct ti_sci_xfer *xfer;
        struct device *dev;
        int ret = 0;

        if (IS_ERR(handle))
                return PTR_ERR(handle);
        if (!handle || !num_parents)
                return -EINVAL;

        info = handle_to_ti_sci_info(handle);
        dev = info->dev;

        xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_GET_NUM_CLOCK_PARENTS,
                                   TI_SCI_FLAG_REQ_ACK_ON_PROCESSED,
                                   sizeof(*req), sizeof(*resp));
        if (IS_ERR(xfer)) {
                ret = PTR_ERR(xfer);
                dev_err(dev, "Message alloc failed(%d)\n", ret);
                return ret;
        }
        req = (struct ti_sci_msg_req_get_clock_num_parents *)xfer->xfer_buf;
        req->dev_id = dev_id;
        req->clk_id = clk_id;

        ret = ti_sci_do_xfer(info, xfer);
        if (ret) {
                dev_err(dev, "Mbox send fail %d\n", ret);
                goto fail;
        }

        resp = (struct ti_sci_msg_resp_get_clock_num_parents *)xfer->xfer_buf;

        if (!ti_sci_is_response_ack(resp))
                ret = -ENODEV;
        else
                *num_parents = resp->num_parents;

fail:
        ti_sci_put_one_xfer(&info->minfo, xfer);

        return ret;
}

/**
 * ti_sci_cmd_clk_get_match_freq() - Find a good match for frequency
 * @handle:     pointer to TI SCI handle
 * @dev_id:     Device identifier this request is for
 * @clk_id:     Clock identifier for the device for this request.
 *              Each device has it's own set of clock inputs. This indexes
 *              which clock input to modify.
 * @min_freq:   The minimum allowable frequency in Hz. This is the minimum
 *              allowable programmed frequency and does not account for clock
 *              tolerances and jitter.
 * @target_freq: The target clock frequency in Hz. A frequency will be
 *              processed as close to this target frequency as possible.
 * @max_freq:   The maximum allowable frequency in Hz. This is the maximum
 *              allowable programmed frequency and does not account for clock
 *              tolerances and jitter.
 * @match_freq: Frequency match in Hz response.
 *
 * Return: 0 if all went well, else returns appropriate error value.
 */
static int ti_sci_cmd_clk_get_match_freq(const struct ti_sci_handle *handle,
                                         u32 dev_id, u8 clk_id, u64 min_freq,
                                         u64 target_freq, u64 max_freq,
                                         u64 *match_freq)
{
        struct ti_sci_info *info;
        struct ti_sci_msg_req_query_clock_freq *req;
        struct ti_sci_msg_resp_query_clock_freq *resp;
        struct ti_sci_xfer *xfer;
        struct device *dev;
        int ret = 0;

        if (IS_ERR(handle))
                return PTR_ERR(handle);
        if (!handle || !match_freq)
                return -EINVAL;

        info = handle_to_ti_sci_info(handle);
        dev = info->dev;

        xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_QUERY_CLOCK_FREQ,
                                   TI_SCI_FLAG_REQ_ACK_ON_PROCESSED,
                                   sizeof(*req), sizeof(*resp));
        if (IS_ERR(xfer)) {
                ret = PTR_ERR(xfer);
                dev_err(dev, "Message alloc failed(%d)\n", ret);
                return ret;
        }
        req = (struct ti_sci_msg_req_query_clock_freq *)xfer->xfer_buf;
        req->dev_id = dev_id;
        req->clk_id = clk_id;
        req->min_freq_hz = min_freq;
        req->target_freq_hz = target_freq;
        req->max_freq_hz = max_freq;

        ret = ti_sci_do_xfer(info, xfer);
        if (ret) {
                dev_err(dev, "Mbox send fail %d\n", ret);
                goto fail;
        }

        resp = (struct ti_sci_msg_resp_query_clock_freq *)xfer->xfer_buf;

        if (!ti_sci_is_response_ack(resp))
                ret = -ENODEV;
        else
                *match_freq = resp->freq_hz;

fail:
        ti_sci_put_one_xfer(&info->minfo, xfer);

        return ret;
}

/**
 * ti_sci_cmd_clk_set_freq() - Set a frequency for clock
 * @handle:     pointer to TI SCI handle
 * @dev_id:     Device identifier this request is for
 * @clk_id:     Clock identifier for the device for this request.
 *              Each device has it's own set of clock inputs. This indexes
 *              which clock input to modify.
 * @min_freq:   The minimum allowable frequency in Hz. This is the minimum
 *              allowable programmed frequency and does not account for clock
 *              tolerances and jitter.
 * @target_freq: The target clock frequency in Hz. A frequency will be
 *              processed as close to this target frequency as possible.
 * @max_freq:   The maximum allowable frequency in Hz. This is the maximum
 *              allowable programmed frequency and does not account for clock
 *              tolerances and jitter.
 *
 * Return: 0 if all went well, else returns appropriate error value.
 */
static int ti_sci_cmd_clk_set_freq(const struct ti_sci_handle *handle,
                                   u32 dev_id, u8 clk_id, u64 min_freq,
                                   u64 target_freq, u64 max_freq)
{
        struct ti_sci_info *info;
        struct ti_sci_msg_req_set_clock_freq *req;
        struct ti_sci_msg_hdr *resp;
        struct ti_sci_xfer *xfer;
        struct device *dev;
        int ret = 0;

        if (IS_ERR(handle))
                return PTR_ERR(handle);
        if (!handle)
                return -EINVAL;

        info = handle_to_ti_sci_info(handle);
        dev = info->dev;

        xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_SET_CLOCK_FREQ,
                                   TI_SCI_FLAG_REQ_ACK_ON_PROCESSED,
                                   sizeof(*req), sizeof(*resp));
        if (IS_ERR(xfer)) {
                ret = PTR_ERR(xfer);
                dev_err(dev, "Message alloc failed(%d)\n", ret);
                return ret;
        }
        req = (struct ti_sci_msg_req_set_clock_freq *)xfer->xfer_buf;
        req->dev_id = dev_id;
        req->clk_id = clk_id;
        req->min_freq_hz = min_freq;
        req->target_freq_hz = target_freq;
        req->max_freq_hz = max_freq;

        ret = ti_sci_do_xfer(info, xfer);
        if (ret) {
                dev_err(dev, "Mbox send fail %d\n", ret);
                goto fail;
        }

        resp = (struct ti_sci_msg_hdr *)xfer->xfer_buf;

        ret = ti_sci_is_response_ack(resp) ? 0 : -ENODEV;

fail:
        ti_sci_put_one_xfer(&info->minfo, xfer);

        return ret;
}

/**
 * ti_sci_cmd_clk_get_freq() - Get current frequency
 * @handle:     pointer to TI SCI handle
 * @dev_id:     Device identifier this request is for
 * @clk_id:     Clock identifier for the device for this request.
 *              Each device has it's own set of clock inputs. This indexes
 *              which clock input to modify.
 * @freq:       Currently frequency in Hz
 *
 * Return: 0 if all went well, else returns appropriate error value.
 */
static int ti_sci_cmd_clk_get_freq(const struct ti_sci_handle *handle,
                                   u32 dev_id, u8 clk_id, u64 *freq)
{
        struct ti_sci_info *info;
        struct ti_sci_msg_req_get_clock_freq *req;
        struct ti_sci_msg_resp_get_clock_freq *resp;
        struct ti_sci_xfer *xfer;
        struct device *dev;
        int ret = 0;

        if (IS_ERR(handle))
                return PTR_ERR(handle);
        if (!handle || !freq)
                return -EINVAL;

        info = handle_to_ti_sci_info(handle);
        dev = info->dev;

        xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_GET_CLOCK_FREQ,
                                   TI_SCI_FLAG_REQ_ACK_ON_PROCESSED,
                                   sizeof(*req), sizeof(*resp));
        if (IS_ERR(xfer)) {
                ret = PTR_ERR(xfer);
                dev_err(dev, "Message alloc failed(%d)\n", ret);
                return ret;
        }
        req = (struct ti_sci_msg_req_get_clock_freq *)xfer->xfer_buf;
        req->dev_id = dev_id;
        req->clk_id = clk_id;

        ret = ti_sci_do_xfer(info, xfer);
        if (ret) {
                dev_err(dev, "Mbox send fail %d\n", ret);
                goto fail;
        }

        resp = (struct ti_sci_msg_resp_get_clock_freq *)xfer->xfer_buf;

        if (!ti_sci_is_response_ack(resp))
                ret = -ENODEV;
        else
                *freq = resp->freq_hz;

fail:
        ti_sci_put_one_xfer(&info->minfo, xfer);

        return ret;
}

static int ti_sci_cmd_core_reboot(const struct ti_sci_handle *handle)
{
        struct ti_sci_info *info;
        struct ti_sci_msg_req_reboot *req;
        struct ti_sci_msg_hdr *resp;
        struct ti_sci_xfer *xfer;
        struct device *dev;
        int ret = 0;

        if (IS_ERR(handle))
                return PTR_ERR(handle);
        if (!handle)
                return -EINVAL;

        info = handle_to_ti_sci_info(handle);
        dev = info->dev;

        xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_SYS_RESET,
                                   TI_SCI_FLAG_REQ_ACK_ON_PROCESSED,
                                   sizeof(*req), sizeof(*resp));
        if (IS_ERR(xfer)) {
                ret = PTR_ERR(xfer);
                dev_err(dev, "Message alloc failed(%d)\n", ret);
                return ret;
        }
        req = (struct ti_sci_msg_req_reboot *)xfer->xfer_buf;

        ret = ti_sci_do_xfer(info, xfer);
        if (ret) {
                dev_err(dev, "Mbox send fail %d\n", ret);
                goto fail;
        }

        resp = (struct ti_sci_msg_hdr *)xfer->xfer_buf;

        if (!ti_sci_is_response_ack(resp))
                ret = -ENODEV;
        else
                ret = 0;

fail:
        ti_sci_put_one_xfer(&info->minfo, xfer);

        return ret;
}

/*
 * ti_sci_setup_ops() - Setup the operations structures
 * @info:       pointer to TISCI pointer
 */
static void ti_sci_setup_ops(struct ti_sci_info *info)
{
        struct ti_sci_ops *ops = &info->handle.ops;
        struct ti_sci_core_ops *core_ops = &ops->core_ops;
        struct ti_sci_dev_ops *dops = &ops->dev_ops;
        struct ti_sci_clk_ops *cops = &ops->clk_ops;

        core_ops->reboot_device = ti_sci_cmd_core_reboot;

        dops->get_device = ti_sci_cmd_get_device;
        dops->idle_device = ti_sci_cmd_idle_device;
        dops->put_device = ti_sci_cmd_put_device;

        dops->is_valid = ti_sci_cmd_dev_is_valid;
        dops->get_context_loss_count = ti_sci_cmd_dev_get_clcnt;
        dops->is_idle = ti_sci_cmd_dev_is_idle;
        dops->is_stop = ti_sci_cmd_dev_is_stop;
        dops->is_on = ti_sci_cmd_dev_is_on;
        dops->is_transitioning = ti_sci_cmd_dev_is_trans;
        dops->set_device_resets = ti_sci_cmd_set_device_resets;
        dops->get_device_resets = ti_sci_cmd_get_device_resets;

        cops->get_clock = ti_sci_cmd_get_clock;
        cops->idle_clock = ti_sci_cmd_idle_clock;
        cops->put_clock = ti_sci_cmd_put_clock;
        cops->is_auto = ti_sci_cmd_clk_is_auto;
        cops->is_on = ti_sci_cmd_clk_is_on;
        cops->is_off = ti_sci_cmd_clk_is_off;

        cops->set_parent = ti_sci_cmd_clk_set_parent;
        cops->get_parent = ti_sci_cmd_clk_get_parent;
        cops->get_num_parents = ti_sci_cmd_clk_get_num_parents;

        cops->get_best_match_freq = ti_sci_cmd_clk_get_match_freq;
        cops->set_freq = ti_sci_cmd_clk_set_freq;
        cops->get_freq = ti_sci_cmd_clk_get_freq;
}

/**
 * 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);

static int tisci_reboot_handler(struct notifier_block *nb, unsigned long mode,
                                void *cmd)
{
        struct ti_sci_info *info = reboot_to_ti_sci_info(nb);
        const struct ti_sci_handle *handle = &info->handle;

        ti_sci_cmd_core_reboot(handle);

        /* call fail OR pass, we should not be here in the first place */
        return NOTIFY_BAD;
}

/* 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;
        int reboot = 0;

        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;
        reboot = of_property_read_bool(dev->of_node,
                                       "ti,system-reboot-controller");
        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_kcalloc(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;
        }

        ti_sci_setup_ops(info);

        if (reboot) {
                info->nb.notifier_call = tisci_reboot_handler;
                info->nb.priority = 128;

                ret = register_restart_handler(&info->nb);
                if (ret) {
                        dev_err(dev, "reboot registration fail(%d)\n", ret);
                        return ret;
                }
        }

        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);

        if (info->nb.notifier_call)
                unregister_restart_handler(&info->nb);

        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");