// SPDX-License-Identifier: GPL-2.0
/*
 * Thermal sensor driver for Allwinner SOC
 * Copyright (C) 2019 Yangtao Li
 *
 * Based on the work of Icenowy Zheng <icenowy@aosc.io>
 * Based on the work of Ondrej Jirman <megous@megous.com>
 * Based on the work of Josef Gajdusek <atx@atx.name>
 */

#include <linux/bitmap.h>
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/nvmem-consumer.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#include <linux/slab.h>
#include <linux/thermal.h>

#include "thermal_hwmon.h"

#define MAX_SENSOR_NUM  4

#define FT_TEMP_MASK                            GENMASK(11, 0)
#define TEMP_CALIB_MASK                         GENMASK(11, 0)
#define CALIBRATE_DEFAULT                       0x800

#define SUN8I_THS_CTRL0                         0x00
#define SUN8I_THS_CTRL2                         0x40
#define SUN8I_THS_IC                            0x44
#define SUN8I_THS_IS                            0x48
#define SUN8I_THS_MFC                           0x70
#define SUN8I_THS_TEMP_CALIB                    0x74
#define SUN8I_THS_TEMP_DATA                     0x80

#define SUN50I_THS_CTRL0                        0x00
#define SUN50I_H6_THS_ENABLE                    0x04
#define SUN50I_H6_THS_PC                        0x08
#define SUN50I_H6_THS_DIC                       0x10
#define SUN50I_H6_THS_DIS                       0x20
#define SUN50I_H6_THS_MFC                       0x30
#define SUN50I_H6_THS_TEMP_CALIB                0xa0
#define SUN50I_H6_THS_TEMP_DATA                 0xc0

#define SUN8I_THS_CTRL0_T_ACQ0(x)               (GENMASK(15, 0) & (x))
#define SUN8I_THS_CTRL2_T_ACQ1(x)               ((GENMASK(15, 0) & (x)) << 16)
#define SUN8I_THS_DATA_IRQ_STS(x)               BIT(x + 8)

#define SUN50I_THS_CTRL0_T_ACQ(x)               ((GENMASK(15, 0) & (x)) << 16)
#define SUN50I_THS_FILTER_EN                    BIT(2)
#define SUN50I_THS_FILTER_TYPE(x)               (GENMASK(1, 0) & (x))
#define SUN50I_H6_THS_PC_TEMP_PERIOD(x)         ((GENMASK(19, 0) & (x)) << 12)
#define SUN50I_H6_THS_DATA_IRQ_STS(x)           BIT(x)

/* millidegree celsius */

struct tsensor {
        struct ths_device               *tmdev;
        struct thermal_zone_device      *tzd;
        int                             id;
};

struct ths_thermal_chip {
        bool            has_mod_clk;
        bool            has_bus_clk_reset;
        int             sensor_num;
        int             offset;
        int             scale;
        int             ft_deviation;
        int             temp_data_base;
        int             (*calibrate)(struct ths_device *tmdev,
                                     u16 *caldata, int callen);
        int             (*init)(struct ths_device *tmdev);
        unsigned long   (*irq_ack)(struct ths_device *tmdev);
        int             (*calc_temp)(struct ths_device *tmdev,
                                     int id, int reg);
};

struct ths_device {
        const struct ths_thermal_chip           *chip;
        struct device                           *dev;
        struct regmap                           *regmap;
        struct reset_control                    *reset;
        struct clk                              *bus_clk;
        struct clk                              *mod_clk;
        struct tsensor                          sensor[MAX_SENSOR_NUM];
};

/* Temp Unit: millidegree Celsius */
static int sun8i_ths_calc_temp(struct ths_device *tmdev,
                               int id, int reg)
{
        return tmdev->chip->offset - (reg * tmdev->chip->scale / 10);
}

static int sun50i_h5_calc_temp(struct ths_device *tmdev,
                               int id, int reg)
{
        if (reg >= 0x500)
                return -1191 * reg / 10 + 223000;
        else if (!id)
                return -1452 * reg / 10 + 259000;
        else
                return -1590 * reg / 10 + 276000;
}

static int sun8i_ths_get_temp(void *data, int *temp)
{
        struct tsensor *s = data;
        struct ths_device *tmdev = s->tmdev;
        int val = 0;

        regmap_read(tmdev->regmap, tmdev->chip->temp_data_base +
                    0x4 * s->id, &val);

        /* ths have no data yet */
        if (!val)
                return -EAGAIN;

        *temp = tmdev->chip->calc_temp(tmdev, s->id, val);
        /*
         * According to the original sdk, there are some platforms(rarely)
         * that add a fixed offset value after calculating the temperature
         * value. We can't simply put it on the formula for calculating the
         * temperature above, because the formula for calculating the
         * temperature above is also used when the sensor is calibrated. If
         * do this, the correct calibration formula is hard to know.
         */
        *temp += tmdev->chip->ft_deviation;

        return 0;
}

static const struct thermal_zone_of_device_ops ths_ops = {
        .get_temp = sun8i_ths_get_temp,
};

static const struct regmap_config config = {
        .reg_bits = 32,
        .val_bits = 32,
        .reg_stride = 4,
        .fast_io = true,
        .max_register = 0xfc,
};

static unsigned long sun8i_h3_irq_ack(struct ths_device *tmdev)
{
        unsigned long irq_bitmap = 0;
        int i, state;

        regmap_read(tmdev->regmap, SUN8I_THS_IS, &state);

        for (i = 0; i < tmdev->chip->sensor_num; i++) {
                if (state & SUN8I_THS_DATA_IRQ_STS(i)) {
                        regmap_write(tmdev->regmap, SUN8I_THS_IS,
                                     SUN8I_THS_DATA_IRQ_STS(i));
                        bitmap_set(&irq_bitmap, i, 1);
                }
        }

        return irq_bitmap;
}

static unsigned long sun50i_h6_irq_ack(struct ths_device *tmdev)
{
        unsigned long irq_bitmap = 0;
        int i, state;

        regmap_read(tmdev->regmap, SUN50I_H6_THS_DIS, &state);

        for (i = 0; i < tmdev->chip->sensor_num; i++) {
                if (state & SUN50I_H6_THS_DATA_IRQ_STS(i)) {
                        regmap_write(tmdev->regmap, SUN50I_H6_THS_DIS,
                                     SUN50I_H6_THS_DATA_IRQ_STS(i));
                        bitmap_set(&irq_bitmap, i, 1);
                }
        }

        return irq_bitmap;
}

static irqreturn_t sun8i_irq_thread(int irq, void *data)
{
        struct ths_device *tmdev = data;
        unsigned long irq_bitmap = tmdev->chip->irq_ack(tmdev);
        int i;

        for_each_set_bit(i, &irq_bitmap, tmdev->chip->sensor_num) {
                thermal_zone_device_update(tmdev->sensor[i].tzd,
                                           THERMAL_EVENT_UNSPECIFIED);
        }

        return IRQ_HANDLED;
}

static int sun8i_h3_ths_calibrate(struct ths_device *tmdev,
                                  u16 *caldata, int callen)
{
        int i;

        if (!caldata[0] || callen < 2 * tmdev->chip->sensor_num)
                return -EINVAL;

        for (i = 0; i < tmdev->chip->sensor_num; i++) {
                int offset = (i % 2) << 4;

                regmap_update_bits(tmdev->regmap,
                                   SUN8I_THS_TEMP_CALIB + (4 * (i >> 1)),
                                   0xfff << offset,
                                   caldata[i] << offset);
        }

        return 0;
}

static int sun50i_h6_ths_calibrate(struct ths_device *tmdev,
                                   u16 *caldata, int callen)
{
        struct device *dev = tmdev->dev;
        int i, ft_temp;

        if (!caldata[0] || callen < 2 + 2 * tmdev->chip->sensor_num)
                return -EINVAL;

        /*
         * efuse layout:
         *
         *      0   11  16       32
         *      +-------+-------+-------+
         *      |temp|  |sensor0|sensor1|
         *      +-------+-------+-------+
         *
         * The calibration data on the H6 is the ambient temperature and
         * sensor values that are filled during the factory test stage.
         *
         * The unit of stored FT temperature is 0.1 degreee celusis.
         *
         * We need to calculate a delta between measured and caluclated
         * register values and this will become a calibration offset.
         */
        ft_temp = (caldata[0] & FT_TEMP_MASK) * 100;

        for (i = 0; i < tmdev->chip->sensor_num; i++) {
                int sensor_reg = caldata[i + 1] & TEMP_CALIB_MASK;
                int cdata, offset;
                int sensor_temp = tmdev->chip->calc_temp(tmdev, i, sensor_reg);

                /*
                 * Calibration data is CALIBRATE_DEFAULT - (calculated
                 * temperature from sensor reading at factory temperature
                 * minus actual factory temperature) * 14.88 (scale from
                 * temperature to register values)
                 */
                cdata = CALIBRATE_DEFAULT -
                        ((sensor_temp - ft_temp) * 10 / tmdev->chip->scale);
                if (cdata & ~TEMP_CALIB_MASK) {
                        /*
                         * Calibration value more than 12-bit, but calibration
                         * register is 12-bit. In this case, ths hardware can
                         * still work without calibration, although the data
                         * won't be so accurate.
                         */
                        dev_warn(dev, "sensor%d is not calibrated.\n", i);
                        continue;
                }

                offset = (i % 2) * 16;
                regmap_update_bits(tmdev->regmap,
                                   SUN50I_H6_THS_TEMP_CALIB + (i / 2 * 4),
                                   0xfff << offset,
                                   cdata << offset);
        }

        return 0;
}

static int sun8i_ths_calibrate(struct ths_device *tmdev)
{
        struct nvmem_cell *calcell;
        struct device *dev = tmdev->dev;
        u16 *caldata;
        size_t callen;
        int ret = 0;

        calcell = devm_nvmem_cell_get(dev, "calibration");
        if (IS_ERR(calcell)) {
                if (PTR_ERR(calcell) == -EPROBE_DEFER)
                        return -EPROBE_DEFER;
                /*
                 * Even if the external calibration data stored in sid is
                 * not accessible, the THS hardware can still work, although
                 * the data won't be so accurate.
                 *
                 * The default value of calibration register is 0x800 for
                 * every sensor, and the calibration value is usually 0x7xx
                 * or 0x8xx, so they won't be away from the default value
                 * for a lot.
                 *
                 * So here we do not return error if the calibration data is
                 * not available, except the probe needs deferring.
                 */
                goto out;
        }

        caldata = nvmem_cell_read(calcell, &callen);
        if (IS_ERR(caldata)) {
                ret = PTR_ERR(caldata);
                goto out;
        }

        tmdev->chip->calibrate(tmdev, caldata, callen);

        kfree(caldata);
out:
        return ret;
}

static int sun8i_ths_resource_init(struct ths_device *tmdev)
{
        struct device *dev = tmdev->dev;
        struct platform_device *pdev = to_platform_device(dev);
        void __iomem *base;
        int ret;

        base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(base))
                return PTR_ERR(base);

        tmdev->regmap = devm_regmap_init_mmio(dev, base, &config);
        if (IS_ERR(tmdev->regmap))
                return PTR_ERR(tmdev->regmap);

        if (tmdev->chip->has_bus_clk_reset) {
                tmdev->reset = devm_reset_control_get(dev, NULL);
                if (IS_ERR(tmdev->reset))
                        return PTR_ERR(tmdev->reset);

                tmdev->bus_clk = devm_clk_get(&pdev->dev, "bus");
                if (IS_ERR(tmdev->bus_clk))
                        return PTR_ERR(tmdev->bus_clk);
        }

        if (tmdev->chip->has_mod_clk) {
                tmdev->mod_clk = devm_clk_get(&pdev->dev, "mod");
                if (IS_ERR(tmdev->mod_clk))
                        return PTR_ERR(tmdev->mod_clk);
        }

        ret = reset_control_deassert(tmdev->reset);
        if (ret)
                return ret;

        ret = clk_prepare_enable(tmdev->bus_clk);
        if (ret)
                goto assert_reset;

        ret = clk_set_rate(tmdev->mod_clk, 24000000);
        if (ret)
                goto bus_disable;

        ret = clk_prepare_enable(tmdev->mod_clk);
        if (ret)
                goto bus_disable;

        ret = sun8i_ths_calibrate(tmdev);
        if (ret)
                goto mod_disable;

        return 0;

mod_disable:
        clk_disable_unprepare(tmdev->mod_clk);
bus_disable:
        clk_disable_unprepare(tmdev->bus_clk);
assert_reset:
        reset_control_assert(tmdev->reset);

        return ret;
}

static int sun8i_h3_thermal_init(struct ths_device *tmdev)
{
        int val;

        /* average over 4 samples */
        regmap_write(tmdev->regmap, SUN8I_THS_MFC,
                     SUN50I_THS_FILTER_EN |
                     SUN50I_THS_FILTER_TYPE(1));
        /*
         * clkin = 24MHz
         * filter_samples = 4
         * period = 0.25s
         *
         * x = period * clkin / 4096 / filter_samples - 1
         *   = 365
         */
        val = GENMASK(7 + tmdev->chip->sensor_num, 8);
        regmap_write(tmdev->regmap, SUN8I_THS_IC,
                     SUN50I_H6_THS_PC_TEMP_PERIOD(365) | val);
        /*
         * T_acq = 20us
         * clkin = 24MHz
         *
         * x = T_acq * clkin - 1
         *   = 479
         */
        regmap_write(tmdev->regmap, SUN8I_THS_CTRL0,
                     SUN8I_THS_CTRL0_T_ACQ0(479));
        val = GENMASK(tmdev->chip->sensor_num - 1, 0);
        regmap_write(tmdev->regmap, SUN8I_THS_CTRL2,
                     SUN8I_THS_CTRL2_T_ACQ1(479) | val);

        return 0;
}

/*
 * Without this undocumented value, the returned temperatures would
 * be higher than real ones by about 20C.
 */
#define SUN50I_H6_CTRL0_UNK 0x0000002f

static int sun50i_h6_thermal_init(struct ths_device *tmdev)
{
        int val;

        /*
         * T_acq = 20us
         * clkin = 24MHz
         *
         * x = T_acq * clkin - 1
         *   = 479
         */
        regmap_write(tmdev->regmap, SUN50I_THS_CTRL0,
                     SUN50I_H6_CTRL0_UNK | SUN50I_THS_CTRL0_T_ACQ(479));
        /* average over 4 samples */
        regmap_write(tmdev->regmap, SUN50I_H6_THS_MFC,
                     SUN50I_THS_FILTER_EN |
                     SUN50I_THS_FILTER_TYPE(1));
        /*
         * clkin = 24MHz
         * filter_samples = 4
         * period = 0.25s
         *
         * x = period * clkin / 4096 / filter_samples - 1
         *   = 365
         */
        regmap_write(tmdev->regmap, SUN50I_H6_THS_PC,
                     SUN50I_H6_THS_PC_TEMP_PERIOD(365));
        /* enable sensor */
        val = GENMASK(tmdev->chip->sensor_num - 1, 0);
        regmap_write(tmdev->regmap, SUN50I_H6_THS_ENABLE, val);
        /* thermal data interrupt enable */
        val = GENMASK(tmdev->chip->sensor_num - 1, 0);
        regmap_write(tmdev->regmap, SUN50I_H6_THS_DIC, val);

        return 0;
}

static int sun8i_ths_register(struct ths_device *tmdev)
{
        int i;

        for (i = 0; i < tmdev->chip->sensor_num; i++) {
                tmdev->sensor[i].tmdev = tmdev;
                tmdev->sensor[i].id = i;
                tmdev->sensor[i].tzd =
                        devm_thermal_zone_of_sensor_register(tmdev->dev,
                                                             i,
                                                             &tmdev->sensor[i],
                                                             &ths_ops);
                if (IS_ERR(tmdev->sensor[i].tzd))
                        return PTR_ERR(tmdev->sensor[i].tzd);

                if (devm_thermal_add_hwmon_sysfs(tmdev->sensor[i].tzd))
                        dev_warn(tmdev->dev,
                                 "Failed to add hwmon sysfs attributes\n");
        }

        return 0;
}

static int sun8i_ths_probe(struct platform_device *pdev)
{
        struct ths_device *tmdev;
        struct device *dev = &pdev->dev;
        int ret, irq;

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

        tmdev->dev = dev;
        tmdev->chip = of_device_get_match_data(&pdev->dev);
        if (!tmdev->chip)
                return -EINVAL;

        platform_set_drvdata(pdev, tmdev);

        ret = sun8i_ths_resource_init(tmdev);
        if (ret)
                return ret;

        irq = platform_get_irq(pdev, 0);
        if (irq < 0)
                return irq;

        ret = tmdev->chip->init(tmdev);
        if (ret)
                return ret;

        ret = sun8i_ths_register(tmdev);
        if (ret)
                return ret;

        /*
         * Avoid entering the interrupt handler, the thermal device is not
         * registered yet, we deffer the registration of the interrupt to
         * the end.
         */
        ret = devm_request_threaded_irq(dev, irq, NULL,
                                        sun8i_irq_thread,
                                        IRQF_ONESHOT, "ths", tmdev);
        if (ret)
                return ret;

        return 0;
}

static int sun8i_ths_remove(struct platform_device *pdev)
{
        struct ths_device *tmdev = platform_get_drvdata(pdev);

        clk_disable_unprepare(tmdev->mod_clk);
        clk_disable_unprepare(tmdev->bus_clk);
        reset_control_assert(tmdev->reset);

        return 0;
}

static const struct ths_thermal_chip sun8i_a83t_ths = {
        .sensor_num = 3,
        .scale = 705,
        .offset = 191668,
        .temp_data_base = SUN8I_THS_TEMP_DATA,
        .calibrate = sun8i_h3_ths_calibrate,
        .init = sun8i_h3_thermal_init,
        .irq_ack = sun8i_h3_irq_ack,
        .calc_temp = sun8i_ths_calc_temp,
};

static const struct ths_thermal_chip sun8i_h3_ths = {
        .sensor_num = 1,
        .scale = 1211,
        .offset = 217000,
        .has_mod_clk = true,
        .has_bus_clk_reset = true,
        .temp_data_base = SUN8I_THS_TEMP_DATA,
        .calibrate = sun8i_h3_ths_calibrate,
        .init = sun8i_h3_thermal_init,
        .irq_ack = sun8i_h3_irq_ack,
        .calc_temp = sun8i_ths_calc_temp,
};

static const struct ths_thermal_chip sun8i_r40_ths = {
        .sensor_num = 2,
        .offset = 251086,
        .scale = 1130,
        .has_mod_clk = true,
        .has_bus_clk_reset = true,
        .temp_data_base = SUN8I_THS_TEMP_DATA,
        .calibrate = sun8i_h3_ths_calibrate,
        .init = sun8i_h3_thermal_init,
        .irq_ack = sun8i_h3_irq_ack,
        .calc_temp = sun8i_ths_calc_temp,
};

static const struct ths_thermal_chip sun50i_a64_ths = {
        .sensor_num = 3,
        .offset = 260890,
        .scale = 1170,
        .has_mod_clk = true,
        .has_bus_clk_reset = true,
        .temp_data_base = SUN8I_THS_TEMP_DATA,
        .calibrate = sun8i_h3_ths_calibrate,
        .init = sun8i_h3_thermal_init,
        .irq_ack = sun8i_h3_irq_ack,
        .calc_temp = sun8i_ths_calc_temp,
};

static const struct ths_thermal_chip sun50i_a100_ths = {
        .sensor_num = 3,
        .has_bus_clk_reset = true,
        .ft_deviation = 8000,
        .offset = 187744,
        .scale = 672,
        .temp_data_base = SUN50I_H6_THS_TEMP_DATA,
        .calibrate = sun50i_h6_ths_calibrate,
        .init = sun50i_h6_thermal_init,
        .irq_ack = sun50i_h6_irq_ack,
        .calc_temp = sun8i_ths_calc_temp,
};

static const struct ths_thermal_chip sun50i_h5_ths = {
        .sensor_num = 2,
        .has_mod_clk = true,
        .has_bus_clk_reset = true,
        .temp_data_base = SUN8I_THS_TEMP_DATA,
        .calibrate = sun8i_h3_ths_calibrate,
        .init = sun8i_h3_thermal_init,
        .irq_ack = sun8i_h3_irq_ack,
        .calc_temp = sun50i_h5_calc_temp,
};

static const struct ths_thermal_chip sun50i_h6_ths = {
        .sensor_num = 2,
        .has_bus_clk_reset = true,
        .ft_deviation = 7000,
        .offset = 187744,
        .scale = 672,
        .temp_data_base = SUN50I_H6_THS_TEMP_DATA,
        .calibrate = sun50i_h6_ths_calibrate,
        .init = sun50i_h6_thermal_init,
        .irq_ack = sun50i_h6_irq_ack,
        .calc_temp = sun8i_ths_calc_temp,
};

static const struct of_device_id of_ths_match[] = {
        { .compatible = "allwinner,sun8i-a83t-ths", .data = &sun8i_a83t_ths },
        { .compatible = "allwinner,sun8i-h3-ths", .data = &sun8i_h3_ths },
        { .compatible = "allwinner,sun8i-r40-ths", .data = &sun8i_r40_ths },
        { .compatible = "allwinner,sun50i-a64-ths", .data = &sun50i_a64_ths },
        { .compatible = "allwinner,sun50i-a100-ths", .data = &sun50i_a100_ths },
        { .compatible = "allwinner,sun50i-h5-ths", .data = &sun50i_h5_ths },
        { .compatible = "allwinner,sun50i-h6-ths", .data = &sun50i_h6_ths },
        { /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, of_ths_match);

static struct platform_driver ths_driver = {
        .probe = sun8i_ths_probe,
        .remove = sun8i_ths_remove,
        .driver = {
                .name = "sun8i-thermal",
                .of_match_table = of_ths_match,
        },
};
module_platform_driver(ths_driver);

MODULE_DESCRIPTION("Thermal sensor driver for Allwinner SOC");
MODULE_LICENSE("GPL v2");