// SPDX-License-Identifier: GPL-2.0-only

/*
 * Copyright (C) 2021, Linaro Limited. All rights reserved.
 */
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqdesc.h>
#include <linux/irqdomain.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/of_platform.h>
#include <linux/slab.h>
#include <linux/firmware/qcom/qcom_scm.h>

#define LMH_NODE_DCVS                   0x44435653
#define LMH_CLUSTER0_NODE_ID            0x6370302D
#define LMH_CLUSTER1_NODE_ID            0x6370312D

#define LMH_SUB_FN_THERMAL              0x54484D4C
#define LMH_SUB_FN_CRNT                 0x43524E54
#define LMH_SUB_FN_REL                  0x52454C00
#define LMH_SUB_FN_BCL                  0x42434C00

#define LMH_ALGO_MODE_ENABLE            0x454E424C
#define LMH_TH_HI_THRESHOLD             0x48494748
#define LMH_TH_LOW_THRESHOLD            0x4C4F5700
#define LMH_TH_ARM_THRESHOLD            0x41524D00

#define LMH_REG_DCVS_INTR_CLR           0x8

#define LMH_ENABLE_ALGOS                1

struct lmh_hw_data {
        void __iomem *base;
        struct irq_domain *domain;
        int irq;
};

static irqreturn_t lmh_handle_irq(int hw_irq, void *data)
{
        struct lmh_hw_data *lmh_data = data;
        int irq = irq_find_mapping(lmh_data->domain, 0);

        /* Call the cpufreq driver to handle the interrupt */
        if (irq)
                generic_handle_irq(irq);

        return IRQ_HANDLED;
}

static void lmh_enable_interrupt(struct irq_data *d)
{
        struct lmh_hw_data *lmh_data = irq_data_get_irq_chip_data(d);

        /* Clear the existing interrupt */
        writel(0xff, lmh_data->base + LMH_REG_DCVS_INTR_CLR);
        enable_irq(lmh_data->irq);
}

static void lmh_disable_interrupt(struct irq_data *d)
{
        struct lmh_hw_data *lmh_data = irq_data_get_irq_chip_data(d);

        disable_irq_nosync(lmh_data->irq);
}

static struct irq_chip lmh_irq_chip = {
        .name           = "lmh",
        .irq_enable     = lmh_enable_interrupt,
        .irq_disable    = lmh_disable_interrupt
};

static int lmh_irq_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
{
        struct lmh_hw_data *lmh_data = d->host_data;
        static struct lock_class_key lmh_lock_key;
        static struct lock_class_key lmh_request_key;

        /*
         * This lock class tells lockdep that GPIO irqs are in a different
         * category than their parents, so it won't report false recursion.
         */
        irq_set_lockdep_class(irq, &lmh_lock_key, &lmh_request_key);
        irq_set_chip_and_handler(irq, &lmh_irq_chip, handle_simple_irq);
        irq_set_chip_data(irq, lmh_data);

        return 0;
}

static const struct irq_domain_ops lmh_irq_ops = {
        .map = lmh_irq_map,
        .xlate = irq_domain_xlate_onecell,
};

static int lmh_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct device_node *np = dev->of_node;
        struct device_node *cpu_node;
        struct lmh_hw_data *lmh_data;
        int temp_low, temp_high, temp_arm, cpu_id, ret;
        unsigned int enable_alg;
        u32 node_id;

        if (!qcom_scm_is_available())
                return -EPROBE_DEFER;

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

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

        cpu_node = of_parse_phandle(np, "cpus", 0);
        if (!cpu_node)
                return -EINVAL;
        cpu_id = of_cpu_node_to_id(cpu_node);
        of_node_put(cpu_node);

        ret = of_property_read_u32(np, "qcom,lmh-temp-high-millicelsius", &temp_high);
        if (ret) {
                dev_err(dev, "missing qcom,lmh-temp-high-millicelsius property\n");
                return ret;
        }

        ret = of_property_read_u32(np, "qcom,lmh-temp-low-millicelsius", &temp_low);
        if (ret) {
                dev_err(dev, "missing qcom,lmh-temp-low-millicelsius property\n");
                return ret;
        }

        ret = of_property_read_u32(np, "qcom,lmh-temp-arm-millicelsius", &temp_arm);
        if (ret) {
                dev_err(dev, "missing qcom,lmh-temp-arm-millicelsius property\n");
                return ret;
        }

        /*
         * Only sdm845 has lmh hardware currently enabled from hlos. If this is needed
         * for other platforms, revisit this to check if the <cpu-id, node-id> should be part
         * of a dt match table.
         */
        if (cpu_id == 0) {
                node_id = LMH_CLUSTER0_NODE_ID;
        } else if (cpu_id == 4) {
                node_id = LMH_CLUSTER1_NODE_ID;
        } else {
                dev_err(dev, "Wrong CPU id associated with LMh node\n");
                return -EINVAL;
        }

        if (!qcom_scm_lmh_dcvsh_available())
                return -EINVAL;

        enable_alg = (uintptr_t)of_device_get_match_data(dev);

        if (enable_alg) {
                ret = qcom_scm_lmh_dcvsh(LMH_SUB_FN_CRNT, LMH_ALGO_MODE_ENABLE, 1,
                                         LMH_NODE_DCVS, node_id, 0);
                if (ret)
                        dev_err(dev, "Error %d enabling current subfunction\n", ret);

                ret = qcom_scm_lmh_dcvsh(LMH_SUB_FN_REL, LMH_ALGO_MODE_ENABLE, 1,
                                         LMH_NODE_DCVS, node_id, 0);
                if (ret)
                        dev_err(dev, "Error %d enabling reliability subfunction\n", ret);

                ret = qcom_scm_lmh_dcvsh(LMH_SUB_FN_BCL, LMH_ALGO_MODE_ENABLE, 1,
                                         LMH_NODE_DCVS, node_id, 0);
                if (ret)
                        dev_err(dev, "Error %d enabling BCL subfunction\n", ret);

                ret = qcom_scm_lmh_dcvsh(LMH_SUB_FN_THERMAL, LMH_ALGO_MODE_ENABLE, 1,
                                         LMH_NODE_DCVS, node_id, 0);
                if (ret) {
                        dev_err(dev, "Error %d enabling thermal subfunction\n", ret);
                        return ret;
                }

                ret = qcom_scm_lmh_profile_change(0x1);
                if (ret) {
                        dev_err(dev, "Error %d changing profile\n", ret);
                        return ret;
                }
        }

        /* Set default thermal trips */
        ret = qcom_scm_lmh_dcvsh(LMH_SUB_FN_THERMAL, LMH_TH_ARM_THRESHOLD, temp_arm,
                                 LMH_NODE_DCVS, node_id, 0);
        if (ret) {
                dev_err(dev, "Error setting thermal ARM threshold%d\n", ret);
                return ret;
        }

        ret = qcom_scm_lmh_dcvsh(LMH_SUB_FN_THERMAL, LMH_TH_HI_THRESHOLD, temp_high,
                                 LMH_NODE_DCVS, node_id, 0);
        if (ret) {
                dev_err(dev, "Error setting thermal HI threshold%d\n", ret);
                return ret;
        }

        ret = qcom_scm_lmh_dcvsh(LMH_SUB_FN_THERMAL, LMH_TH_LOW_THRESHOLD, temp_low,
                                 LMH_NODE_DCVS, node_id, 0);
        if (ret) {
                dev_err(dev, "Error setting thermal LOW threshold%d\n", ret);
                return ret;
        }

        lmh_data->irq = platform_get_irq(pdev, 0);
        lmh_data->domain = irq_domain_create_linear(dev_fwnode(dev), 1, &lmh_irq_ops, lmh_data);
        if (!lmh_data->domain) {
                dev_err(dev, "Error adding irq_domain\n");
                return -EINVAL;
        }

        /* Disable the irq and let cpufreq enable it when ready to handle the interrupt */
        irq_set_status_flags(lmh_data->irq, IRQ_NOAUTOEN);
        ret = devm_request_irq(dev, lmh_data->irq, lmh_handle_irq,
                               IRQF_NO_THREAD | IRQF_NO_SUSPEND,
                               "lmh-irq", lmh_data);
        if (ret) {
                dev_err(dev, "Error %d registering irq %x\n", ret, lmh_data->irq);
                irq_domain_remove(lmh_data->domain);
                return ret;
        }

        return 0;
}

static const struct of_device_id lmh_table[] = {
        { .compatible = "qcom,sc8180x-lmh", },
        { .compatible = "qcom,sdm845-lmh", .data = (void *)LMH_ENABLE_ALGOS},
        { .compatible = "qcom,sm8150-lmh", },
        {}
};
MODULE_DEVICE_TABLE(of, lmh_table);

static struct platform_driver lmh_driver = {
        .probe = lmh_probe,
        .driver = {
                .name = "qcom-lmh",
                .of_match_table = lmh_table,
                .suppress_bind_attrs = true,
        },
};
module_platform_driver(lmh_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("QCOM LMh driver");