/* Copyright 2013-2014 Freescale Semiconductor Inc.
 *
 * I/O services to send MC commands to the MC hardware
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the above-listed copyright holders nor the
 *       names of any contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 *
 * ALTERNATIVELY, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") as published by the Free Software
 * Foundation, either version 2 of that License or (at your option) any
 * later version.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "../include/mc-sys.h"
#include "../include/mc-cmd.h"
#include "../include/mc.h"
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/device.h>
#include "dpmcp.h"

/**
 * Timeout in milliseconds to wait for the completion of an MC command
 */
#define MC_CMD_COMPLETION_TIMEOUT_MS    500

/*
 * usleep_range() min and max values used to throttle down polling
 * iterations while waiting for MC command completion
 */
#define MC_CMD_COMPLETION_POLLING_MIN_SLEEP_USECS    10
#define MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS    500

static enum mc_cmd_status mc_cmd_hdr_read_status(struct mc_command *cmd)
{
        struct mc_cmd_header *hdr = (struct mc_cmd_header *)&cmd->header;

        return (enum mc_cmd_status)hdr->status;
}

static u16 mc_cmd_hdr_read_cmdid(struct mc_command *cmd)
{
        struct mc_cmd_header *hdr = (struct mc_cmd_header *)&cmd->header;
        u16 cmd_id = le16_to_cpu(hdr->cmd_id);

        return (cmd_id & MC_CMD_HDR_CMDID_MASK) >> MC_CMD_HDR_CMDID_SHIFT;
}

/**
 * Creates an MC I/O object
 *
 * @dev: device to be associated with the MC I/O object
 * @mc_portal_phys_addr: physical address of the MC portal to use
 * @mc_portal_size: size in bytes of the MC portal
 * @dpmcp-dev: Pointer to the DPMCP object associated with this MC I/O
 * object or NULL if none.
 * @flags: flags for the new MC I/O object
 * @new_mc_io: Area to return pointer to newly created MC I/O object
 *
 * Returns '0' on Success; Error code otherwise.
 */
int __must_check fsl_create_mc_io(struct device *dev,
                                  phys_addr_t mc_portal_phys_addr,
                                  u32 mc_portal_size,
                                  struct fsl_mc_device *dpmcp_dev,
                                  u32 flags, struct fsl_mc_io **new_mc_io)
{
        int error;
        struct fsl_mc_io *mc_io;
        void __iomem *mc_portal_virt_addr;
        struct resource *res;

        mc_io = devm_kzalloc(dev, sizeof(*mc_io), GFP_KERNEL);
        if (!mc_io)
                return -ENOMEM;

        mc_io->dev = dev;
        mc_io->flags = flags;
        mc_io->portal_phys_addr = mc_portal_phys_addr;
        mc_io->portal_size = mc_portal_size;
        if (flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)
                spin_lock_init(&mc_io->spinlock);
        else
                mutex_init(&mc_io->mutex);

        res = devm_request_mem_region(dev,
                                      mc_portal_phys_addr,
                                      mc_portal_size,
                                      "mc_portal");
        if (!res) {
                dev_err(dev,
                        "devm_request_mem_region failed for MC portal %#llx\n",
                        mc_portal_phys_addr);
                return -EBUSY;
        }

        mc_portal_virt_addr = devm_ioremap_nocache(dev,
                                                   mc_portal_phys_addr,
                                                   mc_portal_size);
        if (!mc_portal_virt_addr) {
                dev_err(dev,
                        "devm_ioremap_nocache failed for MC portal %#llx\n",
                        mc_portal_phys_addr);
                return -ENXIO;
        }

        mc_io->portal_virt_addr = mc_portal_virt_addr;
        if (dpmcp_dev) {
                error = fsl_mc_io_set_dpmcp(mc_io, dpmcp_dev);
                if (error < 0)
                        goto error_destroy_mc_io;
        }

        *new_mc_io = mc_io;
        return 0;

error_destroy_mc_io:
        fsl_destroy_mc_io(mc_io);
        return error;
}
EXPORT_SYMBOL_GPL(fsl_create_mc_io);

/**
 * Destroys an MC I/O object
 *
 * @mc_io: MC I/O object to destroy
 */
void fsl_destroy_mc_io(struct fsl_mc_io *mc_io)
{
        struct fsl_mc_device *dpmcp_dev = mc_io->dpmcp_dev;

        if (dpmcp_dev)
                fsl_mc_io_unset_dpmcp(mc_io);

        devm_iounmap(mc_io->dev, mc_io->portal_virt_addr);
        devm_release_mem_region(mc_io->dev,
                                mc_io->portal_phys_addr,
                                mc_io->portal_size);

        mc_io->portal_virt_addr = NULL;
        devm_kfree(mc_io->dev, mc_io);
}
EXPORT_SYMBOL_GPL(fsl_destroy_mc_io);

int fsl_mc_io_set_dpmcp(struct fsl_mc_io *mc_io,
                        struct fsl_mc_device *dpmcp_dev)
{
        int error;

        if (WARN_ON(!dpmcp_dev))
                return -EINVAL;

        if (WARN_ON(mc_io->dpmcp_dev))
                return -EINVAL;

        if (WARN_ON(dpmcp_dev->mc_io))
                return -EINVAL;

        error = dpmcp_open(mc_io,
                           0,
                           dpmcp_dev->obj_desc.id,
                           &dpmcp_dev->mc_handle);
        if (error < 0)
                return error;

        mc_io->dpmcp_dev = dpmcp_dev;
        dpmcp_dev->mc_io = mc_io;
        return 0;
}
EXPORT_SYMBOL_GPL(fsl_mc_io_set_dpmcp);

void fsl_mc_io_unset_dpmcp(struct fsl_mc_io *mc_io)
{
        int error;
        struct fsl_mc_device *dpmcp_dev = mc_io->dpmcp_dev;

        if (WARN_ON(!dpmcp_dev))
                return;

        if (WARN_ON(dpmcp_dev->mc_io != mc_io))
                return;

        error = dpmcp_close(mc_io,
                            0,
                            dpmcp_dev->mc_handle);
        if (error < 0) {
                dev_err(&dpmcp_dev->dev, "dpmcp_close() failed: %d\n",
                        error);
        }

        mc_io->dpmcp_dev = NULL;
        dpmcp_dev->mc_io = NULL;
}
EXPORT_SYMBOL_GPL(fsl_mc_io_unset_dpmcp);

static int mc_status_to_error(enum mc_cmd_status status)
{
        static const int mc_status_to_error_map[] = {
                [MC_CMD_STATUS_OK] = 0,
                [MC_CMD_STATUS_AUTH_ERR] = -EACCES,
                [MC_CMD_STATUS_NO_PRIVILEGE] = -EPERM,
                [MC_CMD_STATUS_DMA_ERR] = -EIO,
                [MC_CMD_STATUS_CONFIG_ERR] = -ENXIO,
                [MC_CMD_STATUS_TIMEOUT] = -ETIMEDOUT,
                [MC_CMD_STATUS_NO_RESOURCE] = -ENAVAIL,
                [MC_CMD_STATUS_NO_MEMORY] = -ENOMEM,
                [MC_CMD_STATUS_BUSY] = -EBUSY,
                [MC_CMD_STATUS_UNSUPPORTED_OP] = -ENOTSUPP,
                [MC_CMD_STATUS_INVALID_STATE] = -ENODEV,
        };

        if (WARN_ON((u32)status >= ARRAY_SIZE(mc_status_to_error_map)))
                return -EINVAL;

        return mc_status_to_error_map[status];
}

static const char *mc_status_to_string(enum mc_cmd_status status)
{
        static const char *const status_strings[] = {
                [MC_CMD_STATUS_OK] = "Command completed successfully",
                [MC_CMD_STATUS_READY] = "Command ready to be processed",
                [MC_CMD_STATUS_AUTH_ERR] = "Authentication error",
                [MC_CMD_STATUS_NO_PRIVILEGE] = "No privilege",
                [MC_CMD_STATUS_DMA_ERR] = "DMA or I/O error",
                [MC_CMD_STATUS_CONFIG_ERR] = "Configuration error",
                [MC_CMD_STATUS_TIMEOUT] = "Operation timed out",
                [MC_CMD_STATUS_NO_RESOURCE] = "No resources",
                [MC_CMD_STATUS_NO_MEMORY] = "No memory available",
                [MC_CMD_STATUS_BUSY] = "Device is busy",
                [MC_CMD_STATUS_UNSUPPORTED_OP] = "Unsupported operation",
                [MC_CMD_STATUS_INVALID_STATE] = "Invalid state"
        };

        if ((unsigned int)status >= ARRAY_SIZE(status_strings))
                return "Unknown MC error";

        return status_strings[status];
}

/**
 * mc_write_command - writes a command to a Management Complex (MC) portal
 *
 * @portal: pointer to an MC portal
 * @cmd: pointer to a filled command
 */
static inline void mc_write_command(struct mc_command __iomem *portal,
                                    struct mc_command *cmd)
{
        int i;

        /* copy command parameters into the portal */
        for (i = 0; i < MC_CMD_NUM_OF_PARAMS; i++)
                __raw_writeq(cmd->params[i], &portal->params[i]);
        __iowmb();

        /* submit the command by writing the header */
        __raw_writeq(cmd->header, &portal->header);
}

/**
 * mc_read_response - reads the response for the last MC command from a
 * Management Complex (MC) portal
 *
 * @portal: pointer to an MC portal
 * @resp: pointer to command response buffer
 *
 * Returns MC_CMD_STATUS_OK on Success; Error code otherwise.
 */
static inline enum mc_cmd_status mc_read_response(struct mc_command __iomem *
                                                  portal,
                                                  struct mc_command *resp)
{
        int i;
        enum mc_cmd_status status;

        /* Copy command response header from MC portal: */
        __iormb();
        resp->header = __raw_readq(&portal->header);
        __iormb();
        status = mc_cmd_hdr_read_status(resp);
        if (status != MC_CMD_STATUS_OK)
                return status;

        /* Copy command response data from MC portal: */
        for (i = 0; i < MC_CMD_NUM_OF_PARAMS; i++)
                resp->params[i] = __raw_readq(&portal->params[i]);
        __iormb();

        return status;
}

/**
 * Waits for the completion of an MC command doing preemptible polling.
 * uslepp_range() is called between polling iterations.
 *
 * @mc_io: MC I/O object to be used
 * @cmd: command buffer to receive MC response
 * @mc_status: MC command completion status
 */
static int mc_polling_wait_preemptible(struct fsl_mc_io *mc_io,
                                       struct mc_command *cmd,
                                       enum mc_cmd_status *mc_status)
{
        enum mc_cmd_status status;
        unsigned long jiffies_until_timeout =
                jiffies + msecs_to_jiffies(MC_CMD_COMPLETION_TIMEOUT_MS);

        /*
         * Wait for response from the MC hardware:
         */
        for (;;) {
                status = mc_read_response(mc_io->portal_virt_addr, cmd);
                if (status != MC_CMD_STATUS_READY)
                        break;

                /*
                 * TODO: When MC command completion interrupts are supported
                 * call wait function here instead of usleep_range()
                 */
                usleep_range(MC_CMD_COMPLETION_POLLING_MIN_SLEEP_USECS,
                             MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);

                if (time_after_eq(jiffies, jiffies_until_timeout)) {
                        dev_dbg(mc_io->dev,
                                "MC command timed out (portal: %#llx, obj handle: %#x, command: %#x)\n",
                                 mc_io->portal_phys_addr,
                                 (unsigned int)mc_cmd_hdr_read_token(cmd),
                                 (unsigned int)mc_cmd_hdr_read_cmdid(cmd));

                        return -ETIMEDOUT;
                }
        }

        *mc_status = status;
        return 0;
}

/**
 * Waits for the completion of an MC command doing atomic polling.
 * udelay() is called between polling iterations.
 *
 * @mc_io: MC I/O object to be used
 * @cmd: command buffer to receive MC response
 * @mc_status: MC command completion status
 */
static int mc_polling_wait_atomic(struct fsl_mc_io *mc_io,
                                  struct mc_command *cmd,
                                  enum mc_cmd_status *mc_status)
{
        enum mc_cmd_status status;
        unsigned long timeout_usecs = MC_CMD_COMPLETION_TIMEOUT_MS * 1000;

        BUILD_BUG_ON((MC_CMD_COMPLETION_TIMEOUT_MS * 1000) %
                     MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS != 0);

        for (;;) {
                status = mc_read_response(mc_io->portal_virt_addr, cmd);
                if (status != MC_CMD_STATUS_READY)
                        break;

                udelay(MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);
                timeout_usecs -= MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS;
                if (timeout_usecs == 0) {
                        dev_dbg(mc_io->dev,
                                "MC command timed out (portal: %#llx, obj handle: %#x, command: %#x)\n",
                                 mc_io->portal_phys_addr,
                                 (unsigned int)mc_cmd_hdr_read_token(cmd),
                                 (unsigned int)mc_cmd_hdr_read_cmdid(cmd));

                        return -ETIMEDOUT;
                }
        }

        *mc_status = status;
        return 0;
}

/**
 * Sends a command to the MC device using the given MC I/O object
 *
 * @mc_io: MC I/O object to be used
 * @cmd: command to be sent
 *
 * Returns '0' on Success; Error code otherwise.
 */
int mc_send_command(struct fsl_mc_io *mc_io, struct mc_command *cmd)
{
        int error;
        enum mc_cmd_status status;
        unsigned long irq_flags = 0;

        if (WARN_ON(in_irq() &&
                    !(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)))
                return -EINVAL;

        if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)
                spin_lock_irqsave(&mc_io->spinlock, irq_flags);
        else
                mutex_lock(&mc_io->mutex);

        /*
         * Send command to the MC hardware:
         */
        mc_write_command(mc_io->portal_virt_addr, cmd);

        /*
         * Wait for response from the MC hardware:
         */
        if (!(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL))
                error = mc_polling_wait_preemptible(mc_io, cmd, &status);
        else
                error = mc_polling_wait_atomic(mc_io, cmd, &status);

        if (error < 0)
                goto common_exit;

        if (status != MC_CMD_STATUS_OK) {
                dev_dbg(mc_io->dev,
                        "MC command failed: portal: %#llx, obj handle: %#x, command: %#x, status: %s (%#x)\n",
                         mc_io->portal_phys_addr,
                         (unsigned int)mc_cmd_hdr_read_token(cmd),
                         (unsigned int)mc_cmd_hdr_read_cmdid(cmd),
                         mc_status_to_string(status),
                         (unsigned int)status);

                error = mc_status_to_error(status);
                goto common_exit;
        }

        error = 0;
common_exit:
        if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)
                spin_unlock_irqrestore(&mc_io->spinlock, irq_flags);
        else
                mutex_unlock(&mc_io->mutex);

        return error;
}
EXPORT_SYMBOL(mc_send_command);