/*
 *
 * Intel Management Engine Interface (Intel MEI) Linux driver
 * Copyright (c) 2013-2014, Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/uuid.h>
#include <linux/jiffies.h>
#include <linux/interrupt.h>
#include <linux/workqueue.h>
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>

#include <linux/mei.h>


#include "mei_dev.h"
#include "hw-txe.h"

static const struct pci_device_id mei_txe_pci_tbl[] = {
        {PCI_VDEVICE(INTEL, 0x0F18)}, /* Baytrail */
        {PCI_VDEVICE(INTEL, 0x2298)}, /* Cherrytrail */

        {0, }
};
MODULE_DEVICE_TABLE(pci, mei_txe_pci_tbl);

#ifdef CONFIG_PM
static inline void mei_txe_set_pm_domain(struct mei_device *dev);
static inline void mei_txe_unset_pm_domain(struct mei_device *dev);
#else
static inline void mei_txe_set_pm_domain(struct mei_device *dev) {}
static inline void mei_txe_unset_pm_domain(struct mei_device *dev) {}
#endif /* CONFIG_PM */

static void mei_txe_pci_iounmap(struct pci_dev *pdev, struct mei_txe_hw *hw)
{
        int i;

        for (i = SEC_BAR; i < NUM_OF_MEM_BARS; i++) {
                if (hw->mem_addr[i]) {
                        pci_iounmap(pdev, hw->mem_addr[i]);
                        hw->mem_addr[i] = NULL;
                }
        }
}
/**
 * mei_txe_probe - Device Initialization Routine
 *
 * @pdev: PCI device structure
 * @ent: entry in mei_txe_pci_tbl
 *
 * Return: 0 on success, <0 on failure.
 */
static int mei_txe_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{
        struct mei_device *dev;
        struct mei_txe_hw *hw;
        int err;
        int i;

        /* enable pci dev */
        err = pci_enable_device(pdev);
        if (err) {
                dev_err(&pdev->dev, "failed to enable pci device.\n");
                goto end;
        }
        /* set PCI host mastering  */
        pci_set_master(pdev);
        /* pci request regions for mei driver */
        err = pci_request_regions(pdev, KBUILD_MODNAME);
        if (err) {
                dev_err(&pdev->dev, "failed to get pci regions.\n");
                goto disable_device;
        }

        err = pci_set_dma_mask(pdev, DMA_BIT_MASK(36));
        if (err) {
                err = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
                if (err) {
                        dev_err(&pdev->dev, "No suitable DMA available.\n");
                        goto release_regions;
                }
        }

        /* allocates and initializes the mei dev structure */
        dev = mei_txe_dev_init(pdev);
        if (!dev) {
                err = -ENOMEM;
                goto release_regions;
        }
        hw = to_txe_hw(dev);

        /* mapping  IO device memory */
        for (i = SEC_BAR; i < NUM_OF_MEM_BARS; i++) {
                hw->mem_addr[i] = pci_iomap(pdev, i, 0);
                if (!hw->mem_addr[i]) {
                        dev_err(&pdev->dev, "mapping I/O device memory failure.\n");
                        err = -ENOMEM;
                        goto free_device;
                }
        }


        pci_enable_msi(pdev);

        /* clear spurious interrupts */
        mei_clear_interrupts(dev);

        /* request and enable interrupt  */
        if (pci_dev_msi_enabled(pdev))
                err = request_threaded_irq(pdev->irq,
                        NULL,
                        mei_txe_irq_thread_handler,
                        IRQF_ONESHOT, KBUILD_MODNAME, dev);
        else
                err = request_threaded_irq(pdev->irq,
                        mei_txe_irq_quick_handler,
                        mei_txe_irq_thread_handler,
                        IRQF_SHARED, KBUILD_MODNAME, dev);
        if (err) {
                dev_err(&pdev->dev, "mei: request_threaded_irq failure. irq = %d\n",
                        pdev->irq);
                goto free_device;
        }

        if (mei_start(dev)) {
                dev_err(&pdev->dev, "init hw failure.\n");
                err = -ENODEV;
                goto release_irq;
        }

        pm_runtime_set_autosuspend_delay(&pdev->dev, MEI_TXI_RPM_TIMEOUT);
        pm_runtime_use_autosuspend(&pdev->dev);

        err = mei_register(dev, &pdev->dev);
        if (err)
                goto stop;

        pci_set_drvdata(pdev, dev);

        /*
        * For not wake-able HW runtime pm framework
        * can't be used on pci device level.
        * Use domain runtime pm callbacks instead.
        */
        if (!pci_dev_run_wake(pdev))
                mei_txe_set_pm_domain(dev);

        pm_runtime_put_noidle(&pdev->dev);

        return 0;

stop:
        mei_stop(dev);
release_irq:

        mei_cancel_work(dev);

        /* disable interrupts */
        mei_disable_interrupts(dev);

        free_irq(pdev->irq, dev);
        pci_disable_msi(pdev);

free_device:
        mei_txe_pci_iounmap(pdev, hw);

        kfree(dev);
release_regions:
        pci_release_regions(pdev);
disable_device:
        pci_disable_device(pdev);
end:
        dev_err(&pdev->dev, "initialization failed.\n");
        return err;
}

/**
 * mei_txe_remove - Device Removal Routine
 *
 * @pdev: PCI device structure
 *
 * mei_remove is called by the PCI subsystem to alert the driver
 * that it should release a PCI device.
 */
static void mei_txe_remove(struct pci_dev *pdev)
{
        struct mei_device *dev;
        struct mei_txe_hw *hw;

        dev = pci_get_drvdata(pdev);
        if (!dev) {
                dev_err(&pdev->dev, "mei: dev =NULL\n");
                return;
        }

        pm_runtime_get_noresume(&pdev->dev);

        hw = to_txe_hw(dev);

        mei_stop(dev);

        if (!pci_dev_run_wake(pdev))
                mei_txe_unset_pm_domain(dev);

        /* disable interrupts */
        mei_disable_interrupts(dev);
        free_irq(pdev->irq, dev);
        pci_disable_msi(pdev);

        pci_set_drvdata(pdev, NULL);

        mei_txe_pci_iounmap(pdev, hw);

        mei_deregister(dev);

        kfree(dev);

        pci_release_regions(pdev);
        pci_disable_device(pdev);
}


#ifdef CONFIG_PM_SLEEP
static int mei_txe_pci_suspend(struct device *device)
{
        struct pci_dev *pdev = to_pci_dev(device);
        struct mei_device *dev = pci_get_drvdata(pdev);

        if (!dev)
                return -ENODEV;

        dev_dbg(&pdev->dev, "suspend\n");

        mei_stop(dev);

        mei_disable_interrupts(dev);

        free_irq(pdev->irq, dev);
        pci_disable_msi(pdev);

        return 0;
}

static int mei_txe_pci_resume(struct device *device)
{
        struct pci_dev *pdev = to_pci_dev(device);
        struct mei_device *dev;
        int err;

        dev = pci_get_drvdata(pdev);
        if (!dev)
                return -ENODEV;

        pci_enable_msi(pdev);

        mei_clear_interrupts(dev);

        /* request and enable interrupt */
        if (pci_dev_msi_enabled(pdev))
                err = request_threaded_irq(pdev->irq,
                        NULL,
                        mei_txe_irq_thread_handler,
                        IRQF_ONESHOT, KBUILD_MODNAME, dev);
        else
                err = request_threaded_irq(pdev->irq,
                        mei_txe_irq_quick_handler,
                        mei_txe_irq_thread_handler,
                        IRQF_SHARED, KBUILD_MODNAME, dev);
        if (err) {
                dev_err(&pdev->dev, "request_threaded_irq failed: irq = %d.\n",
                                pdev->irq);
                return err;
        }

        err = mei_restart(dev);

        return err;
}
#endif /* CONFIG_PM_SLEEP */

#ifdef CONFIG_PM
static int mei_txe_pm_runtime_idle(struct device *device)
{
        struct pci_dev *pdev = to_pci_dev(device);
        struct mei_device *dev;

        dev_dbg(&pdev->dev, "rpm: txe: runtime_idle\n");

        dev = pci_get_drvdata(pdev);
        if (!dev)
                return -ENODEV;
        if (mei_write_is_idle(dev))
                pm_runtime_autosuspend(device);

        return -EBUSY;
}
static int mei_txe_pm_runtime_suspend(struct device *device)
{
        struct pci_dev *pdev = to_pci_dev(device);
        struct mei_device *dev;
        int ret;

        dev_dbg(&pdev->dev, "rpm: txe: runtime suspend\n");

        dev = pci_get_drvdata(pdev);
        if (!dev)
                return -ENODEV;

        mutex_lock(&dev->device_lock);

        if (mei_write_is_idle(dev))
                ret = mei_txe_aliveness_set_sync(dev, 0);
        else
                ret = -EAGAIN;

        /*
         * If everything is okay we're about to enter PCI low
         * power state (D3) therefor we need to disable the
         * interrupts towards host.
         * However if device is not wakeable we do not enter
         * D-low state and we need to keep the interrupt kicking
         */
        if (!ret && pci_dev_run_wake(pdev))
                mei_disable_interrupts(dev);

        dev_dbg(&pdev->dev, "rpm: txe: runtime suspend ret=%d\n", ret);

        mutex_unlock(&dev->device_lock);
        return ret;
}

static int mei_txe_pm_runtime_resume(struct device *device)
{
        struct pci_dev *pdev = to_pci_dev(device);
        struct mei_device *dev;
        int ret;

        dev_dbg(&pdev->dev, "rpm: txe: runtime resume\n");

        dev = pci_get_drvdata(pdev);
        if (!dev)
                return -ENODEV;

        mutex_lock(&dev->device_lock);

        mei_enable_interrupts(dev);

        ret = mei_txe_aliveness_set_sync(dev, 1);

        mutex_unlock(&dev->device_lock);

        dev_dbg(&pdev->dev, "rpm: txe: runtime resume ret = %d\n", ret);

        return ret;
}

/**
 * mei_txe_set_pm_domain - fill and set pm domain structure for device
 *
 * @dev: mei_device
 */
static inline void mei_txe_set_pm_domain(struct mei_device *dev)
{
        struct pci_dev *pdev  = to_pci_dev(dev->dev);

        if (pdev->dev.bus && pdev->dev.bus->pm) {
                dev->pg_domain.ops = *pdev->dev.bus->pm;

                dev->pg_domain.ops.runtime_suspend = mei_txe_pm_runtime_suspend;
                dev->pg_domain.ops.runtime_resume = mei_txe_pm_runtime_resume;
                dev->pg_domain.ops.runtime_idle = mei_txe_pm_runtime_idle;

                dev_pm_domain_set(&pdev->dev, &dev->pg_domain);
        }
}

/**
 * mei_txe_unset_pm_domain - clean pm domain structure for device
 *
 * @dev: mei_device
 */
static inline void mei_txe_unset_pm_domain(struct mei_device *dev)
{
        /* stop using pm callbacks if any */
        dev_pm_domain_set(dev->dev, NULL);
}

static const struct dev_pm_ops mei_txe_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(mei_txe_pci_suspend,
                                mei_txe_pci_resume)
        SET_RUNTIME_PM_OPS(
                mei_txe_pm_runtime_suspend,
                mei_txe_pm_runtime_resume,
                mei_txe_pm_runtime_idle)
};

#define MEI_TXE_PM_OPS  (&mei_txe_pm_ops)
#else
#define MEI_TXE_PM_OPS  NULL
#endif /* CONFIG_PM */

/*
 *  PCI driver structure
 */
static struct pci_driver mei_txe_driver = {
        .name = KBUILD_MODNAME,
        .id_table = mei_txe_pci_tbl,
        .probe = mei_txe_probe,
        .remove = mei_txe_remove,
        .shutdown = mei_txe_remove,
        .driver.pm = MEI_TXE_PM_OPS,
};

module_pci_driver(mei_txe_driver);

MODULE_AUTHOR("Intel Corporation");
MODULE_DESCRIPTION("Intel(R) Trusted Execution Environment Interface");
MODULE_LICENSE("GPL v2");