// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * ST Thermal Sensor Driver for memory mapped sensors.
 * Author: Ajit Pal Singh <ajitpal.singh@st.com>
 *
 * Copyright (C) 2003-2014 STMicroelectronics (R&D) Limited
 */

#include <linux/of.h>
#include <linux/module.h>

#include "st_thermal.h"

#define STIH416_MPE_CONF                        0x0
#define STIH416_MPE_STATUS                      0x4
#define STIH416_MPE_INT_THRESH                  0x8
#define STIH416_MPE_INT_EN                      0xC

/* Power control bits for the memory mapped thermal sensor */
#define THERMAL_PDN                             BIT(4)
#define THERMAL_SRSTN                           BIT(10)

static const struct reg_field st_mmap_thermal_regfields[MAX_REGFIELDS] = {
        /*
         * According to the STIH416 MPE temp sensor data sheet -
         * the PDN (Power Down Bit) and SRSTN (Soft Reset Bit) need to be
         * written simultaneously for powering on and off the temperature
         * sensor. regmap_update_bits() will be used to update the register.
         */
        [INT_THRESH_HI] = REG_FIELD(STIH416_MPE_INT_THRESH,     0,  7),
        [DCORRECT]      = REG_FIELD(STIH416_MPE_CONF,           5,  9),
        [OVERFLOW]      = REG_FIELD(STIH416_MPE_STATUS,         9,  9),
        [DATA]          = REG_FIELD(STIH416_MPE_STATUS,         11, 18),
        [INT_ENABLE]    = REG_FIELD(STIH416_MPE_INT_EN,         0,  0),
};

static irqreturn_t st_mmap_thermal_trip_handler(int irq, void *sdata)
{
        struct st_thermal_sensor *sensor = sdata;

        thermal_zone_device_update(sensor->thermal_dev,
                                   THERMAL_EVENT_UNSPECIFIED);

        return IRQ_HANDLED;
}

/* Private ops for the Memory Mapped based thermal sensors */
static int st_mmap_power_ctrl(struct st_thermal_sensor *sensor,
                              enum st_thermal_power_state power_state)
{
        const unsigned int mask = (THERMAL_PDN | THERMAL_SRSTN);
        const unsigned int val = power_state ? mask : 0;

        return regmap_update_bits(sensor->regmap, STIH416_MPE_CONF, mask, val);
}

static int st_mmap_alloc_regfields(struct st_thermal_sensor *sensor)
{
        struct device *dev = sensor->dev;
        struct regmap *regmap = sensor->regmap;
        const struct reg_field *reg_fields = sensor->cdata->reg_fields;

        sensor->int_thresh_hi = devm_regmap_field_alloc(dev, regmap,
                                                reg_fields[INT_THRESH_HI]);
        sensor->int_enable = devm_regmap_field_alloc(dev, regmap,
                                                reg_fields[INT_ENABLE]);

        if (IS_ERR(sensor->int_thresh_hi) || IS_ERR(sensor->int_enable)) {
                dev_err(dev, "failed to alloc mmap regfields\n");
                return -EINVAL;
        }

        return 0;
}

static int st_mmap_enable_irq(struct st_thermal_sensor *sensor)
{
        int ret;

        /* Set upper critical threshold */
        ret = regmap_field_write(sensor->int_thresh_hi,
                                 sensor->cdata->crit_temp -
                                 sensor->cdata->temp_adjust_val);
        if (ret)
                return ret;

        return regmap_field_write(sensor->int_enable, 1);
}

static int st_mmap_register_enable_irq(struct st_thermal_sensor *sensor)
{
        struct device *dev = sensor->dev;
        struct platform_device *pdev = to_platform_device(dev);
        int ret;

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

        ret = devm_request_threaded_irq(dev, sensor->irq,
                                        NULL, st_mmap_thermal_trip_handler,
                                        IRQF_TRIGGER_RISING | IRQF_ONESHOT,
                                        dev->driver->name, sensor);
        if (ret) {
                dev_err(dev, "failed to register IRQ %d\n", sensor->irq);
                return ret;
        }

        return st_mmap_enable_irq(sensor);
}

static const struct regmap_config st_416mpe_regmap_config = {
        .reg_bits = 32,
        .val_bits = 32,
        .reg_stride = 4,
};

static int st_mmap_regmap_init(struct st_thermal_sensor *sensor)
{
        struct device *dev = sensor->dev;
        struct platform_device *pdev = to_platform_device(dev);

        sensor->mmio_base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
        if (IS_ERR(sensor->mmio_base))
                return PTR_ERR(sensor->mmio_base);

        sensor->regmap = devm_regmap_init_mmio(dev, sensor->mmio_base,
                                &st_416mpe_regmap_config);
        if (IS_ERR(sensor->regmap)) {
                dev_err(dev, "failed to initialise regmap\n");
                return PTR_ERR(sensor->regmap);
        }

        return 0;
}

static const struct st_thermal_sensor_ops st_mmap_sensor_ops = {
        .power_ctrl             = st_mmap_power_ctrl,
        .alloc_regfields        = st_mmap_alloc_regfields,
        .regmap_init            = st_mmap_regmap_init,
        .register_enable_irq    = st_mmap_register_enable_irq,
        .enable_irq             = st_mmap_enable_irq,
};

/* Compatible device data stih407 thermal sensor */
static const struct st_thermal_compat_data st_407_cdata = {
        .reg_fields             = st_mmap_thermal_regfields,
        .ops                    = &st_mmap_sensor_ops,
        .calibration_val        = 16,
        .temp_adjust_val        = -95,
        .crit_temp              = 120,
};

static const struct of_device_id st_mmap_thermal_of_match[] = {
        { .compatible = "st,stih407-thermal",     .data = &st_407_cdata },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, st_mmap_thermal_of_match);

static int st_mmap_probe(struct platform_device *pdev)
{
        return st_thermal_register(pdev,  st_mmap_thermal_of_match);
}

static void st_mmap_remove(struct platform_device *pdev)
{
        st_thermal_unregister(pdev);
}

static struct platform_driver st_mmap_thermal_driver = {
        .driver = {
                .name   = "st_thermal_mmap",
                .pm     = pm_sleep_ptr(&st_thermal_pm_ops),
                .of_match_table = st_mmap_thermal_of_match,
        },
        .probe          = st_mmap_probe,
        .remove         = st_mmap_remove,
};

module_platform_driver(st_mmap_thermal_driver);

MODULE_AUTHOR("STMicroelectronics (R&D) Limited <ajitpal.singh@st.com>");
MODULE_DESCRIPTION("STMicroelectronics STi SoC Thermal Sensor Driver");
MODULE_LICENSE("GPL v2");