// SPDX-License-Identifier: GPL-2.0-only
/* intel_pch_thermal.c - Intel PCH Thermal driver
 *
 * Copyright (c) 2015, Intel Corporation.
 *
 * Authors:
 *     Tushar Dave <tushar.n.dave@intel.com>
 */

#include <linux/acpi.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/pm.h>
#include <linux/suspend.h>
#include <linux/thermal.h>
#include <linux/types.h>
#include <linux/units.h>

/* Intel PCH thermal Device IDs */
#define PCH_THERMAL_DID_HSW_1   0x9C24 /* Haswell PCH */
#define PCH_THERMAL_DID_HSW_2   0x8C24 /* Haswell PCH */
#define PCH_THERMAL_DID_WPT     0x9CA4 /* Wildcat Point */
#define PCH_THERMAL_DID_SKL     0x9D31 /* Skylake PCH */
#define PCH_THERMAL_DID_SKL_H   0xA131 /* Skylake PCH 100 series */
#define PCH_THERMAL_DID_CNL     0x9Df9 /* CNL PCH */
#define PCH_THERMAL_DID_CNL_H   0xA379 /* CNL-H PCH */
#define PCH_THERMAL_DID_CNL_LP  0x02F9 /* CNL-LP PCH */
#define PCH_THERMAL_DID_CML_H   0X06F9 /* CML-H PCH */
#define PCH_THERMAL_DID_LWB     0xA1B1 /* Lewisburg PCH */
#define PCH_THERMAL_DID_WBG     0x8D24 /* Wellsburg PCH */

/* Wildcat Point-LP  PCH Thermal registers */
#define WPT_TEMP        0x0000  /* Temperature */
#define WPT_TSC 0x04    /* Thermal Sensor Control */
#define WPT_TSS 0x06    /* Thermal Sensor Status */
#define WPT_TSEL        0x08    /* Thermal Sensor Enable and Lock */
#define WPT_TSREL       0x0A    /* Thermal Sensor Report Enable and Lock */
#define WPT_TSMIC       0x0C    /* Thermal Sensor SMI Control */
#define WPT_CTT 0x0010  /* Catastrophic Trip Point */
#define WPT_TSPM        0x001C  /* Thermal Sensor Power Management */
#define WPT_TAHV        0x0014  /* Thermal Alert High Value */
#define WPT_TALV        0x0018  /* Thermal Alert Low Value */
#define WPT_TL          0x00000040      /* Throttle Value */
#define WPT_PHL 0x0060  /* PCH Hot Level */
#define WPT_PHLC        0x62    /* PHL Control */
#define WPT_TAS 0x80    /* Thermal Alert Status */
#define WPT_TSPIEN      0x82    /* PCI Interrupt Event Enables */
#define WPT_TSGPEN      0x84    /* General Purpose Event Enables */

/*  Wildcat Point-LP  PCH Thermal Register bit definitions */
#define WPT_TEMP_TSR    0x01ff  /* Temp TS Reading */
#define WPT_TSC_CPDE    0x01    /* Catastrophic Power-Down Enable */
#define WPT_TSS_TSDSS   0x10    /* Thermal Sensor Dynamic Shutdown Status */
#define WPT_TSS_GPES    0x08    /* GPE status */
#define WPT_TSEL_ETS    0x01    /* Enable TS */
#define WPT_TSEL_PLDB   0x80    /* TSEL Policy Lock-Down Bit */
#define WPT_TL_TOL      0x000001FF      /* T0 Level */
#define WPT_TL_T1L      0x1ff00000      /* T1 Level */
#define WPT_TL_TTEN     0x20000000      /* TT Enable */

/* Resolution of 1/2 degree C and an offset of -50C */
#define PCH_TEMP_OFFSET (-50)
#define GET_WPT_TEMP(x) ((x) * MILLIDEGREE_PER_DEGREE / 2 + WPT_TEMP_OFFSET)
#define WPT_TEMP_OFFSET (PCH_TEMP_OFFSET * MILLIDEGREE_PER_DEGREE)
#define GET_PCH_TEMP(x) (((x) / 2) + PCH_TEMP_OFFSET)

#define PCH_MAX_TRIPS 3 /* critical, hot, passive */

/* Amount of time for each cooling delay, 100ms by default for now */
static unsigned int delay_timeout = 100;
module_param(delay_timeout, int, 0644);
MODULE_PARM_DESC(delay_timeout, "amount of time delay for each iteration.");

/* Number of iterations for cooling delay, 600 counts by default for now */
static unsigned int delay_cnt = 600;
module_param(delay_cnt, int, 0644);
MODULE_PARM_DESC(delay_cnt, "total number of iterations for time delay.");

static char driver_name[] = "Intel PCH thermal driver";

struct pch_thermal_device {
        void __iomem *hw_base;
        struct pci_dev *pdev;
        struct thermal_zone_device *tzd;
        bool bios_enabled;
};

#ifdef CONFIG_ACPI
/*
 * On some platforms, there is a companion ACPI device, which adds
 * passive trip temperature using _PSV method. There is no specific
 * passive temperature setting in MMIO interface of this PCI device.
 */
static int pch_wpt_add_acpi_psv_trip(struct pch_thermal_device *ptd,
                                     struct thermal_trip *trip)
{
        struct acpi_device *adev;
        int temp;

        adev = ACPI_COMPANION(&ptd->pdev->dev);
        if (!adev)
                return 0;

        if (thermal_acpi_passive_trip_temp(adev, &temp) || temp <= 0)
                return 0;

        trip->type = THERMAL_TRIP_PASSIVE;
        trip->temperature = temp;
        return 1;
}
#else
static int pch_wpt_add_acpi_psv_trip(struct pch_thermal_device *ptd,
                                     struct thermal_trip *trip)
{
        return 0;
}
#endif

static int pch_thermal_get_temp(struct thermal_zone_device *tzd, int *temp)
{
        struct pch_thermal_device *ptd = thermal_zone_device_priv(tzd);

        *temp = GET_WPT_TEMP(WPT_TEMP_TSR & readw(ptd->hw_base + WPT_TEMP));
        return 0;
}

static void pch_critical(struct thermal_zone_device *tzd)
{
        dev_dbg(thermal_zone_device(tzd), "%s: critical temperature reached\n",
                thermal_zone_device_type(tzd));
}

static const struct thermal_zone_device_ops tzd_ops = {
        .get_temp = pch_thermal_get_temp,
        .critical = pch_critical,
};

enum pch_board_ids {
        PCH_BOARD_HSW = 0,
        PCH_BOARD_WPT,
        PCH_BOARD_SKL,
        PCH_BOARD_CNL,
        PCH_BOARD_CML,
        PCH_BOARD_LWB,
        PCH_BOARD_WBG,
};

static const char *board_names[] = {
        [PCH_BOARD_HSW] = "pch_haswell",
        [PCH_BOARD_WPT] = "pch_wildcat_point",
        [PCH_BOARD_SKL] = "pch_skylake",
        [PCH_BOARD_CNL] = "pch_cannonlake",
        [PCH_BOARD_CML] = "pch_cometlake",
        [PCH_BOARD_LWB] = "pch_lewisburg",
        [PCH_BOARD_WBG] = "pch_wellsburg",
};

static int intel_pch_thermal_probe(struct pci_dev *pdev,
                                   const struct pci_device_id *id)
{
        struct thermal_trip ptd_trips[PCH_MAX_TRIPS] = { 0 };
        enum pch_board_ids board_id = id->driver_data;
        struct pch_thermal_device *ptd;
        int nr_trips = 0;
        u16 trip_temp;
        u8 tsel;
        int err;

        ptd = devm_kzalloc(&pdev->dev, sizeof(*ptd), GFP_KERNEL);
        if (!ptd)
                return -ENOMEM;

        pci_set_drvdata(pdev, ptd);
        ptd->pdev = pdev;

        err = pci_enable_device(pdev);
        if (err) {
                dev_err(&pdev->dev, "failed to enable pci device\n");
                return err;
        }

        err = pci_request_regions(pdev, driver_name);
        if (err) {
                dev_err(&pdev->dev, "failed to request pci region\n");
                goto error_disable;
        }

        ptd->hw_base = pci_ioremap_bar(pdev, 0);
        if (!ptd->hw_base) {
                err = -ENOMEM;
                dev_err(&pdev->dev, "failed to map mem base\n");
                goto error_release;
        }

        /* Check if BIOS has already enabled thermal sensor */
        if (WPT_TSEL_ETS & readb(ptd->hw_base + WPT_TSEL)) {
                ptd->bios_enabled = true;
                goto read_trips;
        }

        tsel = readb(ptd->hw_base + WPT_TSEL);
        /*
         * When TSEL's Policy Lock-Down bit is 1, TSEL become RO.
         * If so, thermal sensor cannot enable. Bail out.
         */
        if (tsel & WPT_TSEL_PLDB) {
                dev_err(&ptd->pdev->dev, "Sensor can't be enabled\n");
                err = -ENODEV;
                goto error_cleanup;
        }

        writeb(tsel|WPT_TSEL_ETS, ptd->hw_base + WPT_TSEL);
        if (!(WPT_TSEL_ETS & readb(ptd->hw_base + WPT_TSEL))) {
                dev_err(&ptd->pdev->dev, "Sensor can't be enabled\n");
                err = -ENODEV;
                goto error_cleanup;
        }

read_trips:
        trip_temp = readw(ptd->hw_base + WPT_CTT);
        trip_temp &= 0x1FF;
        if (trip_temp) {
                ptd_trips[nr_trips].temperature = GET_WPT_TEMP(trip_temp);
                ptd_trips[nr_trips++].type = THERMAL_TRIP_CRITICAL;
        }

        trip_temp = readw(ptd->hw_base + WPT_PHL);
        trip_temp &= 0x1FF;
        if (trip_temp) {
                ptd_trips[nr_trips].temperature = GET_WPT_TEMP(trip_temp);
                ptd_trips[nr_trips++].type = THERMAL_TRIP_HOT;
        }

        nr_trips += pch_wpt_add_acpi_psv_trip(ptd, &ptd_trips[nr_trips]);

        ptd->tzd = thermal_zone_device_register_with_trips(board_names[board_id],
                                                           ptd_trips, nr_trips,
                                                           ptd, &tzd_ops,
                                                           NULL, 0, 0);
        if (IS_ERR(ptd->tzd)) {
                dev_err(&pdev->dev, "Failed to register thermal zone %s\n",
                        board_names[board_id]);
                err = PTR_ERR(ptd->tzd);
                goto error_cleanup;
        }
        err = thermal_zone_device_enable(ptd->tzd);
        if (err)
                goto err_unregister;

        return 0;

err_unregister:
        thermal_zone_device_unregister(ptd->tzd);
error_cleanup:
        iounmap(ptd->hw_base);
error_release:
        pci_release_regions(pdev);
error_disable:
        pci_disable_device(pdev);
        dev_err(&pdev->dev, "pci device failed to probe\n");
        return err;
}

static void intel_pch_thermal_remove(struct pci_dev *pdev)
{
        struct pch_thermal_device *ptd = pci_get_drvdata(pdev);

        thermal_zone_device_unregister(ptd->tzd);
        iounmap(ptd->hw_base);
        pci_release_regions(pdev);
        pci_disable_device(pdev);
}

static int intel_pch_thermal_suspend_noirq(struct device *device)
{
        struct pch_thermal_device *ptd = dev_get_drvdata(device);
        u16 pch_thr_temp, pch_cur_temp;
        int pch_delay_cnt = 0;
        u8 tsel;

        /* Shutdown the thermal sensor if it is not enabled by BIOS */
        if (!ptd->bios_enabled) {
                tsel = readb(ptd->hw_base + WPT_TSEL);
                writeb(tsel & 0xFE, ptd->hw_base + WPT_TSEL);
                return 0;
        }

        /* Do not check temperature if it is not s2idle */
        if (pm_suspend_via_firmware())
                return 0;

        /* Get the PCH temperature threshold value */
        pch_thr_temp = GET_PCH_TEMP(WPT_TEMP_TSR & readw(ptd->hw_base + WPT_TSPM));

        /* Get the PCH current temperature value */
        pch_cur_temp = GET_PCH_TEMP(WPT_TEMP_TSR & readw(ptd->hw_base + WPT_TEMP));

        if (pch_cur_temp >= pch_thr_temp)
                dev_warn(&ptd->pdev->dev,
                        "CPU-PCH current temp [%dC] higher than the threshold temp [%dC], S0ix might fail. Start cooling...\n",
                        pch_cur_temp, pch_thr_temp);

        /*
         * If current PCH temperature is higher than configured PCH threshold
         * value, run some delay loop with sleep to let the current temperature
         * go down below the threshold value which helps to allow system enter
         * lower power S0ix suspend state. Even after delay loop if PCH current
         * temperature stays above threshold, notify the warning message
         * which helps to indentify the reason why S0ix entry was rejected.
         */
        while (pch_delay_cnt < delay_cnt) {
                if (pch_cur_temp < pch_thr_temp)
                        break;

                if (pm_wakeup_pending()) {
                        dev_warn(&ptd->pdev->dev, "Wakeup event detected, abort cooling\n");
                        return 0;
                }

                pch_delay_cnt++;
                dev_dbg(&ptd->pdev->dev,
                        "CPU-PCH current temp [%dC] higher than the threshold temp [%dC], sleep %d times for %d ms duration\n",
                        pch_cur_temp, pch_thr_temp, pch_delay_cnt, delay_timeout);
                msleep(delay_timeout);
                /* Read the PCH current temperature for next cycle. */
                pch_cur_temp = GET_PCH_TEMP(WPT_TEMP_TSR & readw(ptd->hw_base + WPT_TEMP));
        }

        if (pch_cur_temp >= pch_thr_temp)
                dev_warn(&ptd->pdev->dev,
                        "CPU-PCH is hot [%dC] after %d ms delay. S0ix might fail\n",
                        pch_cur_temp, pch_delay_cnt * delay_timeout);
        else {
                if (pch_delay_cnt)
                        dev_info(&ptd->pdev->dev,
                                "CPU-PCH is cool [%dC] after %d ms delay\n",
                                pch_cur_temp, pch_delay_cnt * delay_timeout);
                else
                        dev_info(&ptd->pdev->dev,
                                "CPU-PCH is cool [%dC]\n",
                                pch_cur_temp);
        }

        return 0;
}

static int intel_pch_thermal_resume(struct device *device)
{
        struct pch_thermal_device *ptd = dev_get_drvdata(device);
        u8 tsel;

        if (ptd->bios_enabled)
                return 0;

        tsel = readb(ptd->hw_base + WPT_TSEL);

        writeb(tsel | WPT_TSEL_ETS, ptd->hw_base + WPT_TSEL);

        return 0;
}

static const struct pci_device_id intel_pch_thermal_id[] = {
        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCH_THERMAL_DID_HSW_1),
                .driver_data = PCH_BOARD_HSW, },
        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCH_THERMAL_DID_HSW_2),
                .driver_data = PCH_BOARD_HSW, },
        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCH_THERMAL_DID_WPT),
                .driver_data = PCH_BOARD_WPT, },
        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCH_THERMAL_DID_SKL),
                .driver_data = PCH_BOARD_SKL, },
        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCH_THERMAL_DID_SKL_H),
                .driver_data = PCH_BOARD_SKL, },
        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCH_THERMAL_DID_CNL),
                .driver_data = PCH_BOARD_CNL, },
        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCH_THERMAL_DID_CNL_H),
                .driver_data = PCH_BOARD_CNL, },
        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCH_THERMAL_DID_CNL_LP),
                .driver_data = PCH_BOARD_CNL, },
        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCH_THERMAL_DID_CML_H),
                .driver_data = PCH_BOARD_CML, },
        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCH_THERMAL_DID_LWB),
                .driver_data = PCH_BOARD_LWB, },
        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCH_THERMAL_DID_WBG),
                .driver_data = PCH_BOARD_WBG, },
        { 0, },
};
MODULE_DEVICE_TABLE(pci, intel_pch_thermal_id);

static const struct dev_pm_ops intel_pch_pm_ops = {
        .suspend_noirq = intel_pch_thermal_suspend_noirq,
        .resume = intel_pch_thermal_resume,
};

static struct pci_driver intel_pch_thermal_driver = {
        .name           = "intel_pch_thermal",
        .id_table       = intel_pch_thermal_id,
        .probe          = intel_pch_thermal_probe,
        .remove         = intel_pch_thermal_remove,
        .driver.pm      = &intel_pch_pm_ops,
};

module_pci_driver(intel_pch_thermal_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Intel PCH Thermal driver");