/*
 * Copyright (c) 2015 MediaTek Inc.
 * Author: Hanyi Wu <hanyi.wu@mediatek.com>
 *         Sascha Hauer <s.hauer@pengutronix.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that 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/clk.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/nvmem-consumer.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/thermal.h>
#include <linux/reset.h>
#include <linux/types.h>

/* AUXADC Registers */
#define AUXADC_CON0_V           0x000
#define AUXADC_CON1_V           0x004
#define AUXADC_CON1_SET_V       0x008
#define AUXADC_CON1_CLR_V       0x00c
#define AUXADC_CON2_V           0x010
#define AUXADC_DATA(channel)    (0x14 + (channel) * 4)
#define AUXADC_MISC_V           0x094

#define AUXADC_CON1_CHANNEL(x)  BIT(x)

#define APMIXED_SYS_TS_CON1     0x604

/* Thermal Controller Registers */
#define TEMP_MONCTL0            0x000
#define TEMP_MONCTL1            0x004
#define TEMP_MONCTL2            0x008
#define TEMP_MONIDET0           0x014
#define TEMP_MONIDET1           0x018
#define TEMP_MSRCTL0            0x038
#define TEMP_AHBPOLL            0x040
#define TEMP_AHBTO              0x044
#define TEMP_ADCPNP0            0x048
#define TEMP_ADCPNP1            0x04c
#define TEMP_ADCPNP2            0x050
#define TEMP_ADCPNP3            0x0b4

#define TEMP_ADCMUX             0x054
#define TEMP_ADCEN              0x060
#define TEMP_PNPMUXADDR         0x064
#define TEMP_ADCMUXADDR         0x068
#define TEMP_ADCENADDR          0x074
#define TEMP_ADCVALIDADDR       0x078
#define TEMP_ADCVOLTADDR        0x07c
#define TEMP_RDCTRL             0x080
#define TEMP_ADCVALIDMASK       0x084
#define TEMP_ADCVOLTAGESHIFT    0x088
#define TEMP_ADCWRITECTRL       0x08c
#define TEMP_MSR0               0x090
#define TEMP_MSR1               0x094
#define TEMP_MSR2               0x098
#define TEMP_MSR3               0x0B8

#define TEMP_SPARE0             0x0f0

#define PTPCORESEL              0x400

#define TEMP_MONCTL1_PERIOD_UNIT(x)     ((x) & 0x3ff)

#define TEMP_MONCTL2_FILTER_INTERVAL(x) (((x) & 0x3ff) << 16)
#define TEMP_MONCTL2_SENSOR_INTERVAL(x) ((x) & 0x3ff)

#define TEMP_AHBPOLL_ADC_POLL_INTERVAL(x)       (x)

#define TEMP_ADCWRITECTRL_ADC_PNP_WRITE         BIT(0)
#define TEMP_ADCWRITECTRL_ADC_MUX_WRITE         BIT(1)

#define TEMP_ADCVALIDMASK_VALID_HIGH            BIT(5)
#define TEMP_ADCVALIDMASK_VALID_POS(bit)        (bit)

#define MT8173_TS1      0
#define MT8173_TS2      1
#define MT8173_TS3      2
#define MT8173_TS4      3
#define MT8173_TSABB    4

/* AUXADC channel 11 is used for the temperature sensors */
#define MT8173_TEMP_AUXADC_CHANNEL      11

/* The total number of temperature sensors in the MT8173 */
#define MT8173_NUM_SENSORS              5

/* The number of banks in the MT8173 */
#define MT8173_NUM_ZONES                4

/* The number of sensing points per bank */
#define MT8173_NUM_SENSORS_PER_ZONE     4

/* Layout of the fuses providing the calibration data */
#define MT8173_CALIB_BUF0_VALID         BIT(0)
#define MT8173_CALIB_BUF1_ADC_GE(x)     (((x) >> 22) & 0x3ff)
#define MT8173_CALIB_BUF0_VTS_TS1(x)    (((x) >> 17) & 0x1ff)
#define MT8173_CALIB_BUF0_VTS_TS2(x)    (((x) >> 8) & 0x1ff)
#define MT8173_CALIB_BUF1_VTS_TS3(x)    (((x) >> 0) & 0x1ff)
#define MT8173_CALIB_BUF2_VTS_TS4(x)    (((x) >> 23) & 0x1ff)
#define MT8173_CALIB_BUF2_VTS_TSABB(x)  (((x) >> 14) & 0x1ff)
#define MT8173_CALIB_BUF0_DEGC_CALI(x)  (((x) >> 1) & 0x3f)
#define MT8173_CALIB_BUF0_O_SLOPE(x)    (((x) >> 26) & 0x3f)

#define THERMAL_NAME    "mtk-thermal"

struct mtk_thermal;

struct mtk_thermal_bank {
        struct mtk_thermal *mt;
        int id;
};

struct mtk_thermal {
        struct device *dev;
        void __iomem *thermal_base;

        struct clk *clk_peri_therm;
        struct clk *clk_auxadc;

        struct mtk_thermal_bank banks[MT8173_NUM_ZONES];

        /* lock: for getting and putting banks */
        struct mutex lock;

        /* Calibration values */
        s32 adc_ge;
        s32 degc_cali;
        s32 o_slope;
        s32 vts[MT8173_NUM_SENSORS];

        struct thermal_zone_device *tzd;
};

struct mtk_thermal_bank_cfg {
        unsigned int num_sensors;
        unsigned int sensors[MT8173_NUM_SENSORS_PER_ZONE];
};

static const int sensor_mux_values[MT8173_NUM_SENSORS] = { 0, 1, 2, 3, 16 };

/*
 * The MT8173 thermal controller has four banks. Each bank can read up to
 * four temperature sensors simultaneously. The MT8173 has a total of 5
 * temperature sensors. We use each bank to measure a certain area of the
 * SoC. Since TS2 is located centrally in the SoC it is influenced by multiple
 * areas, hence is used in different banks.
 *
 * The thermal core only gets the maximum temperature of all banks, so
 * the bank concept wouldn't be necessary here. However, the SVS (Smart
 * Voltage Scaling) unit makes its decisions based on the same bank
 * data, and this indeed needs the temperatures of the individual banks
 * for making better decisions.
 */
static const struct mtk_thermal_bank_cfg bank_data[] = {
        {
                .num_sensors = 2,
                .sensors = { MT8173_TS2, MT8173_TS3 },
        }, {
                .num_sensors = 2,
                .sensors = { MT8173_TS2, MT8173_TS4 },
        }, {
                .num_sensors = 3,
                .sensors = { MT8173_TS1, MT8173_TS2, MT8173_TSABB },
        }, {
                .num_sensors = 1,
                .sensors = { MT8173_TS2 },
        },
};

struct mtk_thermal_sense_point {
        int msr;
        int adcpnp;
};

static const struct mtk_thermal_sense_point
                sensing_points[MT8173_NUM_SENSORS_PER_ZONE] = {
        {
                .msr = TEMP_MSR0,
                .adcpnp = TEMP_ADCPNP0,
        }, {
                .msr = TEMP_MSR1,
                .adcpnp = TEMP_ADCPNP1,
        }, {
                .msr = TEMP_MSR2,
                .adcpnp = TEMP_ADCPNP2,
        }, {
                .msr = TEMP_MSR3,
                .adcpnp = TEMP_ADCPNP3,
        },
};

/**
 * raw_to_mcelsius - convert a raw ADC value to mcelsius
 * @mt:         The thermal controller
 * @raw:        raw ADC value
 *
 * This converts the raw ADC value to mcelsius using the SoC specific
 * calibration constants
 */
static int raw_to_mcelsius(struct mtk_thermal *mt, int sensno, s32 raw)
{
        s32 tmp;

        raw &= 0xfff;

        tmp = 203450520 << 3;
        tmp /= 165 + mt->o_slope;
        tmp /= 10000 + mt->adc_ge;
        tmp *= raw - mt->vts[sensno] - 3350;
        tmp >>= 3;

        return mt->degc_cali * 500 - tmp;
}

/**
 * mtk_thermal_get_bank - get bank
 * @bank:       The bank
 *
 * The bank registers are banked, we have to select a bank in the
 * PTPCORESEL register to access it.
 */
static void mtk_thermal_get_bank(struct mtk_thermal_bank *bank)
{
        struct mtk_thermal *mt = bank->mt;
        u32 val;

        mutex_lock(&mt->lock);

        val = readl(mt->thermal_base + PTPCORESEL);
        val &= ~0xf;
        val |= bank->id;
        writel(val, mt->thermal_base + PTPCORESEL);
}

/**
 * mtk_thermal_put_bank - release bank
 * @bank:       The bank
 *
 * release a bank previously taken with mtk_thermal_get_bank,
 */
static void mtk_thermal_put_bank(struct mtk_thermal_bank *bank)
{
        struct mtk_thermal *mt = bank->mt;

        mutex_unlock(&mt->lock);
}

/**
 * mtk_thermal_bank_temperature - get the temperature of a bank
 * @bank:       The bank
 *
 * The temperature of a bank is considered the maximum temperature of
 * the sensors associated to the bank.
 */
static int mtk_thermal_bank_temperature(struct mtk_thermal_bank *bank)
{
        struct mtk_thermal *mt = bank->mt;
        int i, temp = INT_MIN, max = INT_MIN;
        u32 raw;

        for (i = 0; i < bank_data[bank->id].num_sensors; i++) {
                raw = readl(mt->thermal_base + sensing_points[i].msr);

                temp = raw_to_mcelsius(mt, bank_data[bank->id].sensors[i], raw);

                /*
                 * The first read of a sensor often contains very high bogus
                 * temperature value. Filter these out so that the system does
                 * not immediately shut down.
                 */
                if (temp > 200000)
                        temp = 0;

                if (temp > max)
                        max = temp;
        }

        return max;
}

static int mtk_read_temp(void *data, int *temperature)
{
        struct mtk_thermal *mt = data;
        int i;
        int tempmax = INT_MIN;

        for (i = 0; i < MT8173_NUM_ZONES; i++) {
                struct mtk_thermal_bank *bank = &mt->banks[i];

                mtk_thermal_get_bank(bank);

                tempmax = max(tempmax, mtk_thermal_bank_temperature(bank));

                mtk_thermal_put_bank(bank);
        }

        *temperature = tempmax;

        return 0;
}

static const struct thermal_zone_of_device_ops mtk_thermal_ops = {
        .get_temp = mtk_read_temp,
};

static void mtk_thermal_init_bank(struct mtk_thermal *mt, int num,
                                  u32 apmixed_phys_base, u32 auxadc_phys_base)
{
        struct mtk_thermal_bank *bank = &mt->banks[num];
        const struct mtk_thermal_bank_cfg *cfg = &bank_data[num];
        int i;

        bank->id = num;
        bank->mt = mt;

        mtk_thermal_get_bank(bank);

        /* bus clock 66M counting unit is 12 * 15.15ns * 256 = 46.540us */
        writel(TEMP_MONCTL1_PERIOD_UNIT(12), mt->thermal_base + TEMP_MONCTL1);

        /*
         * filt interval is 1 * 46.540us = 46.54us,
         * sen interval is 429 * 46.540us = 19.96ms
         */
        writel(TEMP_MONCTL2_FILTER_INTERVAL(1) |
                        TEMP_MONCTL2_SENSOR_INTERVAL(429),
                        mt->thermal_base + TEMP_MONCTL2);

        /* poll is set to 10u */
        writel(TEMP_AHBPOLL_ADC_POLL_INTERVAL(768),
               mt->thermal_base + TEMP_AHBPOLL);

        /* temperature sampling control, 1 sample */
        writel(0x0, mt->thermal_base + TEMP_MSRCTL0);

        /* exceed this polling time, IRQ would be inserted */
        writel(0xffffffff, mt->thermal_base + TEMP_AHBTO);

        /* number of interrupts per event, 1 is enough */
        writel(0x0, mt->thermal_base + TEMP_MONIDET0);
        writel(0x0, mt->thermal_base + TEMP_MONIDET1);

        /*
         * The MT8173 thermal controller does not have its own ADC. Instead it
         * uses AHB bus accesses to control the AUXADC. To do this the thermal
         * controller has to be programmed with the physical addresses of the
         * AUXADC registers and with the various bit positions in the AUXADC.
         * Also the thermal controller controls a mux in the APMIXEDSYS register
         * space.
         */

        /*
         * this value will be stored to TEMP_PNPMUXADDR (TEMP_SPARE0)
         * automatically by hw
         */
        writel(BIT(MT8173_TEMP_AUXADC_CHANNEL), mt->thermal_base + TEMP_ADCMUX);

        /* AHB address for auxadc mux selection */
        writel(auxadc_phys_base + AUXADC_CON1_CLR_V,
               mt->thermal_base + TEMP_ADCMUXADDR);

        /* AHB address for pnp sensor mux selection */
        writel(apmixed_phys_base + APMIXED_SYS_TS_CON1,
               mt->thermal_base + TEMP_PNPMUXADDR);

        /* AHB value for auxadc enable */
        writel(BIT(MT8173_TEMP_AUXADC_CHANNEL), mt->thermal_base + TEMP_ADCEN);

        /* AHB address for auxadc enable (channel 0 immediate mode selected) */
        writel(auxadc_phys_base + AUXADC_CON1_SET_V,
               mt->thermal_base + TEMP_ADCENADDR);

        /* AHB address for auxadc valid bit */
        writel(auxadc_phys_base + AUXADC_DATA(MT8173_TEMP_AUXADC_CHANNEL),
               mt->thermal_base + TEMP_ADCVALIDADDR);

        /* AHB address for auxadc voltage output */
        writel(auxadc_phys_base + AUXADC_DATA(MT8173_TEMP_AUXADC_CHANNEL),
               mt->thermal_base + TEMP_ADCVOLTADDR);

        /* read valid & voltage are at the same register */
        writel(0x0, mt->thermal_base + TEMP_RDCTRL);

        /* indicate where the valid bit is */
        writel(TEMP_ADCVALIDMASK_VALID_HIGH | TEMP_ADCVALIDMASK_VALID_POS(12),
               mt->thermal_base + TEMP_ADCVALIDMASK);

        /* no shift */
        writel(0x0, mt->thermal_base + TEMP_ADCVOLTAGESHIFT);

        /* enable auxadc mux write transaction */
        writel(TEMP_ADCWRITECTRL_ADC_MUX_WRITE,
               mt->thermal_base + TEMP_ADCWRITECTRL);

        for (i = 0; i < cfg->num_sensors; i++)
                writel(sensor_mux_values[cfg->sensors[i]],
                       mt->thermal_base + sensing_points[i].adcpnp);

        writel((1 << cfg->num_sensors) - 1, mt->thermal_base + TEMP_MONCTL0);

        writel(TEMP_ADCWRITECTRL_ADC_PNP_WRITE |
               TEMP_ADCWRITECTRL_ADC_MUX_WRITE,
               mt->thermal_base + TEMP_ADCWRITECTRL);

        mtk_thermal_put_bank(bank);
}

static u64 of_get_phys_base(struct device_node *np)
{
        u64 size64;
        const __be32 *regaddr_p;

        regaddr_p = of_get_address(np, 0, &size64, NULL);
        if (!regaddr_p)
                return OF_BAD_ADDR;

        return of_translate_address(np, regaddr_p);
}

static int mtk_thermal_get_calibration_data(struct device *dev,
                                            struct mtk_thermal *mt)
{
        struct nvmem_cell *cell;
        u32 *buf;
        size_t len;
        int i, ret = 0;

        /* Start with default values */
        mt->adc_ge = 512;
        for (i = 0; i < MT8173_NUM_SENSORS; i++)
                mt->vts[i] = 260;
        mt->degc_cali = 40;
        mt->o_slope = 0;

        cell = nvmem_cell_get(dev, "calibration-data");
        if (IS_ERR(cell)) {
                if (PTR_ERR(cell) == -EPROBE_DEFER)
                        return PTR_ERR(cell);
                return 0;
        }

        buf = (u32 *)nvmem_cell_read(cell, &len);

        nvmem_cell_put(cell);

        if (IS_ERR(buf))
                return PTR_ERR(buf);

        if (len < 3 * sizeof(u32)) {
                dev_warn(dev, "invalid calibration data\n");
                ret = -EINVAL;
                goto out;
        }

        if (buf[0] & MT8173_CALIB_BUF0_VALID) {
                mt->adc_ge = MT8173_CALIB_BUF1_ADC_GE(buf[1]);
                mt->vts[MT8173_TS1] = MT8173_CALIB_BUF0_VTS_TS1(buf[0]);
                mt->vts[MT8173_TS2] = MT8173_CALIB_BUF0_VTS_TS2(buf[0]);
                mt->vts[MT8173_TS3] = MT8173_CALIB_BUF1_VTS_TS3(buf[1]);
                mt->vts[MT8173_TS4] = MT8173_CALIB_BUF2_VTS_TS4(buf[2]);
                mt->vts[MT8173_TSABB] = MT8173_CALIB_BUF2_VTS_TSABB(buf[2]);
                mt->degc_cali = MT8173_CALIB_BUF0_DEGC_CALI(buf[0]);
                mt->o_slope = MT8173_CALIB_BUF0_O_SLOPE(buf[0]);
        } else {
                dev_info(dev, "Device not calibrated, using default calibration values\n");
        }

out:
        kfree(buf);

        return ret;
}

static int mtk_thermal_probe(struct platform_device *pdev)
{
        int ret, i;
        struct device_node *auxadc, *apmixedsys, *np = pdev->dev.of_node;
        struct mtk_thermal *mt;
        struct resource *res;
        u64 auxadc_phys_base, apmixed_phys_base;

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

        mt->clk_peri_therm = devm_clk_get(&pdev->dev, "therm");
        if (IS_ERR(mt->clk_peri_therm))
                return PTR_ERR(mt->clk_peri_therm);

        mt->clk_auxadc = devm_clk_get(&pdev->dev, "auxadc");
        if (IS_ERR(mt->clk_auxadc))
                return PTR_ERR(mt->clk_auxadc);

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        mt->thermal_base = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(mt->thermal_base))
                return PTR_ERR(mt->thermal_base);

        ret = mtk_thermal_get_calibration_data(&pdev->dev, mt);
        if (ret)
                return ret;

        mutex_init(&mt->lock);

        mt->dev = &pdev->dev;

        auxadc = of_parse_phandle(np, "mediatek,auxadc", 0);
        if (!auxadc) {
                dev_err(&pdev->dev, "missing auxadc node\n");
                return -ENODEV;
        }

        auxadc_phys_base = of_get_phys_base(auxadc);

        of_node_put(auxadc);

        if (auxadc_phys_base == OF_BAD_ADDR) {
                dev_err(&pdev->dev, "Can't get auxadc phys address\n");
                return -EINVAL;
        }

        apmixedsys = of_parse_phandle(np, "mediatek,apmixedsys", 0);
        if (!apmixedsys) {
                dev_err(&pdev->dev, "missing apmixedsys node\n");
                return -ENODEV;
        }

        apmixed_phys_base = of_get_phys_base(apmixedsys);

        of_node_put(apmixedsys);

        if (apmixed_phys_base == OF_BAD_ADDR) {
                dev_err(&pdev->dev, "Can't get auxadc phys address\n");
                return -EINVAL;
        }

        ret = clk_prepare_enable(mt->clk_auxadc);
        if (ret) {
                dev_err(&pdev->dev, "Can't enable auxadc clk: %d\n", ret);
                return ret;
        }

        ret = device_reset(&pdev->dev);
        if (ret)
                goto err_disable_clk_auxadc;

        ret = clk_prepare_enable(mt->clk_peri_therm);
        if (ret) {
                dev_err(&pdev->dev, "Can't enable peri clk: %d\n", ret);
                goto err_disable_clk_auxadc;
        }

        for (i = 0; i < MT8173_NUM_ZONES; i++)
                mtk_thermal_init_bank(mt, i, apmixed_phys_base,
                                      auxadc_phys_base);

        platform_set_drvdata(pdev, mt);

        mt->tzd = thermal_zone_of_sensor_register(&pdev->dev, 0, mt,
                                &mtk_thermal_ops);
        if (IS_ERR(mt->tzd))
                goto err_register;

        return 0;

err_register:
        clk_disable_unprepare(mt->clk_peri_therm);

err_disable_clk_auxadc:
        clk_disable_unprepare(mt->clk_auxadc);

        return ret;
}

static int mtk_thermal_remove(struct platform_device *pdev)
{
        struct mtk_thermal *mt = platform_get_drvdata(pdev);

        thermal_zone_of_sensor_unregister(&pdev->dev, mt->tzd);

        clk_disable_unprepare(mt->clk_peri_therm);
        clk_disable_unprepare(mt->clk_auxadc);

        return 0;
}

static const struct of_device_id mtk_thermal_of_match[] = {
        {
                .compatible = "mediatek,mt8173-thermal",
        }, {
        },
};

static struct platform_driver mtk_thermal_driver = {
        .probe = mtk_thermal_probe,
        .remove = mtk_thermal_remove,
        .driver = {
                .name = THERMAL_NAME,
                .of_match_table = mtk_thermal_of_match,
        },
};

module_platform_driver(mtk_thermal_driver);

MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
MODULE_AUTHOR("Hanyi Wu <hanyi.wu@mediatek.com>");
MODULE_DESCRIPTION("Mediatek thermal driver");
MODULE_LICENSE("GPL v2");