/*
 * PCI glue for ISHTP provider device (ISH) driver
 *
 * Copyright (c) 2014-2016, 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/moduleparam.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/sched.h>
#include <linux/interrupt.h>
#include <linux/workqueue.h>
#define CREATE_TRACE_POINTS
#include <trace/events/intel_ish.h>
#include "ishtp-dev.h"
#include "hw-ish.h"

static const struct pci_device_id ish_pci_tbl[] = {
        {PCI_DEVICE(PCI_VENDOR_ID_INTEL, CHV_DEVICE_ID)},
        {PCI_DEVICE(PCI_VENDOR_ID_INTEL, BXT_Ax_DEVICE_ID)},
        {PCI_DEVICE(PCI_VENDOR_ID_INTEL, BXT_Bx_DEVICE_ID)},
        {PCI_DEVICE(PCI_VENDOR_ID_INTEL, APL_Ax_DEVICE_ID)},
        {PCI_DEVICE(PCI_VENDOR_ID_INTEL, SPT_Ax_DEVICE_ID)},
        {PCI_DEVICE(PCI_VENDOR_ID_INTEL, CNL_Ax_DEVICE_ID)},
        {PCI_DEVICE(PCI_VENDOR_ID_INTEL, GLK_Ax_DEVICE_ID)},
        {PCI_DEVICE(PCI_VENDOR_ID_INTEL, CNL_H_DEVICE_ID)},
        {0, }
};
MODULE_DEVICE_TABLE(pci, ish_pci_tbl);

/**
 * ish_event_tracer() - Callback function to dump trace messages
 * @dev:        ishtp device
 * @format:     printf style format
 *
 * Callback to direct log messages to Linux trace buffers
 */
static __printf(2, 3)
void ish_event_tracer(struct ishtp_device *dev, const char *format, ...)
{
        if (trace_ishtp_dump_enabled()) {
                va_list args;
                char tmp_buf[100];

                va_start(args, format);
                vsnprintf(tmp_buf, sizeof(tmp_buf), format, args);
                va_end(args);

                trace_ishtp_dump(tmp_buf);
        }
}

/**
 * ish_init() - Init function
 * @dev:        ishtp device
 *
 * This function initialize wait queues for suspend/resume and call
 * calls hadware initialization function. This will initiate
 * startup sequence
 *
 * Return: 0 for success or error code for failure
 */
static int ish_init(struct ishtp_device *dev)
{
        int ret;

        /* Set the state of ISH HW to start */
        ret = ish_hw_start(dev);
        if (ret) {
                dev_err(dev->devc, "ISH: hw start failed.\n");
                return ret;
        }

        /* Start the inter process communication to ISH processor */
        ret = ishtp_start(dev);
        if (ret) {
                dev_err(dev->devc, "ISHTP: Protocol init failed.\n");
                return ret;
        }

        return 0;
}

/**
 * ish_probe() - PCI driver probe callback
 * @pdev:       pci device
 * @ent:        pci device id
 *
 * Initialize PCI function, setup interrupt and call for ISH initialization
 *
 * Return: 0 for success or error code for failure
 */
static int ish_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{
        struct ishtp_device *dev;
        struct ish_hw *hw;
        int     ret;

        /* enable pci dev */
        ret = pci_enable_device(pdev);
        if (ret) {
                dev_err(&pdev->dev, "ISH: Failed to enable PCI device\n");
                return ret;
        }

        /* set PCI host mastering */
        pci_set_master(pdev);

        /* pci request regions for ISH driver */
        ret = pci_request_regions(pdev, KBUILD_MODNAME);
        if (ret) {
                dev_err(&pdev->dev, "ISH: Failed to get PCI regions\n");
                goto disable_device;
        }

        /* allocates and initializes the ISH dev structure */
        dev = ish_dev_init(pdev);
        if (!dev) {
                ret = -ENOMEM;
                goto release_regions;
        }
        hw = to_ish_hw(dev);
        dev->print_log = ish_event_tracer;

        /* mapping IO device memory */
        hw->mem_addr = pci_iomap(pdev, 0, 0);
        if (!hw->mem_addr) {
                dev_err(&pdev->dev, "ISH: mapping I/O range failure\n");
                ret = -ENOMEM;
                goto free_device;
        }

        dev->pdev = pdev;

        pdev->dev_flags |= PCI_DEV_FLAGS_NO_D3;

        /* request and enable interrupt */
        ret = request_irq(pdev->irq, ish_irq_handler, IRQF_SHARED,
                          KBUILD_MODNAME, dev);
        if (ret) {
                dev_err(&pdev->dev, "ISH: request IRQ failure (%d)\n",
                        pdev->irq);
                goto free_device;
        }

        dev_set_drvdata(dev->devc, dev);

        init_waitqueue_head(&dev->suspend_wait);
        init_waitqueue_head(&dev->resume_wait);

        ret = ish_init(dev);
        if (ret)
                goto free_irq;

        return 0;

free_irq:
        free_irq(pdev->irq, dev);
free_device:
        pci_iounmap(pdev, hw->mem_addr);
        kfree(dev);
release_regions:
        pci_release_regions(pdev);
disable_device:
        pci_clear_master(pdev);
        pci_disable_device(pdev);
        dev_err(&pdev->dev, "ISH: PCI driver initialization failed.\n");

        return ret;
}

/**
 * ish_remove() - PCI driver remove callback
 * @pdev:       pci device
 *
 * This function does cleanup of ISH on pci remove callback
 */
static void ish_remove(struct pci_dev *pdev)
{
        struct ishtp_device *ishtp_dev = pci_get_drvdata(pdev);
        struct ish_hw *hw = to_ish_hw(ishtp_dev);

        ishtp_bus_remove_all_clients(ishtp_dev, false);
        ish_device_disable(ishtp_dev);

        free_irq(pdev->irq, ishtp_dev);
        pci_iounmap(pdev, hw->mem_addr);
        pci_release_regions(pdev);
        pci_clear_master(pdev);
        pci_disable_device(pdev);
        kfree(ishtp_dev);
}

#ifdef CONFIG_PM
static struct device *ish_resume_device;

/* 50ms to get resume response */
#define WAIT_FOR_RESUME_ACK_MS          50

/**
 * ish_resume_handler() - Work function to complete resume
 * @work:       work struct
 *
 * The resume work function to complete resume function asynchronously.
 * There are two resume paths, one where ISH is not powered off,
 * in that case a simple resume message is enough, others we need
 * a reset sequence.
 */
static void ish_resume_handler(struct work_struct *work)
{
        struct pci_dev *pdev = to_pci_dev(ish_resume_device);
        struct ishtp_device *dev = pci_get_drvdata(pdev);
        uint32_t fwsts;
        int ret;

        /* Get ISH FW status */
        fwsts = IPC_GET_ISH_FWSTS(dev->ops->get_fw_status(dev));

        /*
         * If currently, in ISH FW, sensor app is loaded or beyond that,
         * it means ISH isn't powered off, in this case, send a resume message.
         */
        if (fwsts >= FWSTS_SENSOR_APP_LOADED) {
                ishtp_send_resume(dev);

                /* Waiting to get resume response */
                if (dev->resume_flag)
                        ret = wait_event_interruptible_timeout(dev->resume_wait,
                                !dev->resume_flag,
                                msecs_to_jiffies(WAIT_FOR_RESUME_ACK_MS));
        }

        /*
         * If in ISH FW, sensor app isn't loaded yet, or no resume response.
         * That means this platform is not S0ix compatible, or something is
         * wrong with ISH FW. So on resume, full reboot of ISH processor will
         * happen, so need to go through init sequence again.
         */
        if (dev->resume_flag)
                ish_init(dev);
}

/**
 * ish_suspend() - ISH suspend callback
 * @device:     device pointer
 *
 * ISH suspend callback
 *
 * Return: 0 to the pm core
 */
static int ish_suspend(struct device *device)
{
        struct pci_dev *pdev = to_pci_dev(device);
        struct ishtp_device *dev = pci_get_drvdata(pdev);

        enable_irq_wake(pdev->irq);
        /*
         * If previous suspend hasn't been asnwered then ISH is likely dead,
         * don't attempt nested notification
         */
        if (dev->suspend_flag)
                return  0;

        dev->resume_flag = 0;
        dev->suspend_flag = 1;
        ishtp_send_suspend(dev);

        /* 25 ms should be enough for live ISH to flush all IPC buf */
        if (dev->suspend_flag)
                wait_event_interruptible_timeout(dev->suspend_wait,
                                                 !dev->suspend_flag,
                                                  msecs_to_jiffies(25));

        return 0;
}

static DECLARE_WORK(resume_work, ish_resume_handler);
/**
 * ish_resume() - ISH resume callback
 * @device:     device pointer
 *
 * ISH resume callback
 *
 * Return: 0 to the pm core
 */
static int ish_resume(struct device *device)
{
        struct pci_dev *pdev = to_pci_dev(device);
        struct ishtp_device *dev = pci_get_drvdata(pdev);

        ish_resume_device = device;
        dev->resume_flag = 1;

        disable_irq_wake(pdev->irq);
        schedule_work(&resume_work);

        return 0;
}

static const struct dev_pm_ops ish_pm_ops = {
        .suspend = ish_suspend,
        .resume = ish_resume,
};
#define ISHTP_ISH_PM_OPS        (&ish_pm_ops)
#else
#define ISHTP_ISH_PM_OPS        NULL
#endif /* CONFIG_PM */

static struct pci_driver ish_driver = {
        .name = KBUILD_MODNAME,
        .id_table = ish_pci_tbl,
        .probe = ish_probe,
        .remove = ish_remove,
        .driver.pm = ISHTP_ISH_PM_OPS,
};

module_pci_driver(ish_driver);

/* Original author */
MODULE_AUTHOR("Daniel Drubin <daniel.drubin@intel.com>");
/* Adoption to upstream Linux kernel */
MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");

MODULE_DESCRIPTION("Intel(R) Integrated Sensor Hub PCI Device Driver");
MODULE_LICENSE("GPL");