// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2016-2021, The Linux Foundation. All rights reserved.
 * Copyright (c) 2021-2022, Qualcomm Innovation Center, Inc. All rights reserved.
 */

#define pr_fmt(fmt) "%s:%s " fmt, KBUILD_MODNAME, __func__

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/thermal.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/timer.h>
#include <linux/pm_opp.h>
#include <linux/atomic.h>
#include <linux/regulator/consumer.h>

#include <asm/smp_plat.h>

#define LIMITS_DCVSH			0x10
#define LIMITS_NODE_DCVS		0x44435653

#define LIMITS_SUB_FN_THERMAL		0x54484D4C
#define LIMITS_HI_THRESHOLD		0x48494748
#define LIMITS_LOW_THRESHOLD		0x4C4F5700
#define LIMITS_ARM_THRESHOLD		0x41524D00

#define LIMITS_CLUSTER_0		0x6370302D
#define LIMITS_CLUSTER_1		0x6370312D

#define LIMITS_FREQ_CAP			0x46434150

#define LIMITS_TEMP_DEFAULT		75000
#define LIMITS_TEMP_HIGH_THRESH_MAX	120000
#define LIMITS_LOW_THRESHOLD_OFFSET	500
#define LIMITS_POLLING_DELAY_MS		10
#define LIMITS_CLUSTER_REQ_OFFSET	0x704
#define LIMITS_CLUSTER_INT_CLR_OFFSET	0x8
#define dcvsh_get_frequency(_val, _max) do { \
	_max = (_val) & 0x3FF; \
	_max *= 19200; \
} while (0)
#define FREQ_KHZ_TO_HZ(_val) ((_val) * 1000)
#define FREQ_HZ_TO_KHZ(_val) ((_val) / 1000)

enum lmh_hw_trips {
	LIMITS_TRIP_ARM,
	LIMITS_TRIP_HI,
	LIMITS_TRIP_MAX,
};

struct __limits_cdev_data {
	struct thermal_cooling_device *cdev;
	u32 max_freq;
};

struct limits_dcvs_hw {
	char sensor_name[THERMAL_NAME_LENGTH];
	uint32_t affinity;
	int irq_num;
	void *osm_hw_reg;
	void *int_clr_reg;
	cpumask_t core_map;
	struct delayed_work freq_poll_work;
	unsigned long max_freq[NR_CPUS];
	unsigned long hw_freq_limit;
	struct device_attribute lmh_freq_attr;
	struct list_head list;
	bool is_irq_enabled;
	struct mutex access_lock;
	struct __limits_cdev_data *cdev_data;
	uint32_t cdev_registered;
	struct regulator *isens_reg[2];
};

LIST_HEAD(lmh_dcvs_hw_list);
DEFINE_MUTEX(lmh_dcvs_list_access);

static void limits_dcvs_get_freq_limits(struct limits_dcvs_hw *hw)
{
	unsigned long freq_ceil = UINT_MAX, freq_floor = 0;
	struct device *cpu_dev = NULL;
	uint32_t cpu, idx = 0;

	for_each_cpu(cpu, &hw->core_map) {
		freq_ceil = UINT_MAX;
		freq_floor = 0;
		cpu_dev = get_cpu_device(cpu);
		if (!cpu_dev) {
			pr_err("Error in get CPU%d device\n", cpu);
			idx++;
			continue;
		}

		dev_pm_opp_find_freq_floor(cpu_dev, &freq_ceil);
		dev_pm_opp_find_freq_ceil(cpu_dev, &freq_floor);

		hw->max_freq[idx] = freq_ceil / 1000;
		idx++;
	}
}

static unsigned long limits_mitigation_notify(struct limits_dcvs_hw *hw)
{
	uint32_t val = 0, max_cpu_ct = 0, max_cpu_limit = 0, idx = 0, cpu = 0;
	struct device *cpu_dev = NULL;
	unsigned long freq_val, max_limit = 0;
	struct dev_pm_opp *opp_entry;

	val = readl_relaxed(hw->osm_hw_reg);
	dcvsh_get_frequency(val, max_limit);
	for_each_cpu(cpu, &hw->core_map) {
		cpu_dev = get_cpu_device(cpu);
		if (!cpu_dev) {
			pr_err("Error in get CPU%d device\n",
				cpumask_first(&hw->core_map));
			goto notify_exit;
		}

		pr_debug("CPU:%d max value read:%lu\n",
			cpumask_first(&hw->core_map),
			max_limit);
		freq_val = FREQ_KHZ_TO_HZ(max_limit);
		opp_entry = dev_pm_opp_find_freq_floor(cpu_dev, &freq_val);
		/*
		 * Hardware mitigation frequency can be lower than the lowest
		 * possible CPU frequency. In that case freq floor call will
		 * fail with -ERANGE and we need to match to the lowest
		 * frequency using freq_ceil.
		 */
		if (IS_ERR(opp_entry) && PTR_ERR(opp_entry) == -ERANGE) {
			opp_entry = dev_pm_opp_find_freq_ceil(cpu_dev,
								&freq_val);
			if (IS_ERR(opp_entry))
				dev_err(cpu_dev,
					"frequency:%lu. opp error:%ld\n",
					freq_val, PTR_ERR(opp_entry));
		}
		if (FREQ_HZ_TO_KHZ(freq_val) == hw->max_freq[idx]) {
			max_cpu_ct++;
			if (max_cpu_limit < hw->max_freq[idx])
				max_cpu_limit = hw->max_freq[idx];
			idx++;
			continue;
		}
		max_limit = FREQ_HZ_TO_KHZ(freq_val);
		break;
	}

	if (max_cpu_ct == cpumask_weight(&hw->core_map))
		max_limit = max_cpu_limit;

	pr_debug("CPU:%d max limit:%lu\n", cpumask_first(&hw->core_map),
			max_limit);

notify_exit:
	hw->hw_freq_limit = max_limit;
	return max_limit;
}

static void limits_dcvs_poll(struct work_struct *work)
{
	unsigned long max_limit = 0;
	struct limits_dcvs_hw *hw = container_of(work,
					struct limits_dcvs_hw,
					freq_poll_work.work);
	int cpu_ct = 0, cpu = 0, idx = 0;

	mutex_lock(&hw->access_lock);
	if (hw->max_freq[0] == U32_MAX)
		limits_dcvs_get_freq_limits(hw);
	max_limit = limits_mitigation_notify(hw);
	for_each_cpu(cpu, &hw->core_map) {
		if (max_limit >= hw->max_freq[idx])
			cpu_ct++;
		idx++;
	}
	if (cpu_ct >= cpumask_weight(&hw->core_map)) {
		writel_relaxed(0xFF, hw->int_clr_reg);
		hw->is_irq_enabled = true;
		enable_irq(hw->irq_num);
	} else {
		mod_delayed_work(system_highpri_wq, &hw->freq_poll_work,
			 msecs_to_jiffies(LIMITS_POLLING_DELAY_MS));
	}
	mutex_unlock(&hw->access_lock);
}

static void lmh_dcvs_notify(struct limits_dcvs_hw *hw)
{
	if (hw->is_irq_enabled) {
		hw->is_irq_enabled = false;
		disable_irq_nosync(hw->irq_num);
		limits_mitigation_notify(hw);
		mod_delayed_work(system_highpri_wq, &hw->freq_poll_work,
			 msecs_to_jiffies(LIMITS_POLLING_DELAY_MS));
	}
}

static irqreturn_t lmh_dcvs_handle_isr(int irq, void *data)
{
	struct limits_dcvs_hw *hw = data;

	mutex_lock(&hw->access_lock);
	lmh_dcvs_notify(hw);
	mutex_unlock(&hw->access_lock);

	return IRQ_HANDLED;
}

static void limits_isens_qref_init(struct platform_device *pdev,
					struct limits_dcvs_hw *hw,
					int idx, char *reg_name,
					char *reg_setting)
{
	int ret = 0;
	uint32_t settings[3];

	ret = of_property_read_u32_array(pdev->dev.of_node,
					reg_setting, settings, 3);
	if (ret) {
		if (ret == -EINVAL)
			return;

		pr_err("Regulator:isens_vref settings read error:%d\n",
				ret);
		return;
	}
	hw->isens_reg[idx] = devm_regulator_get(&pdev->dev, reg_name);
	if (IS_ERR_OR_NULL(hw->isens_reg[idx])) {
		pr_err("Regulator:isens_vref init error:%ld\n",
			PTR_ERR(hw->isens_reg[idx]));
		return;
	}
	ret = regulator_set_voltage(hw->isens_reg[idx], settings[0],
					settings[1]);
	if (ret) {
		pr_err("Regulator:isens_vref set voltage error:%d\n", ret);
		return;
	}
	ret = regulator_set_load(hw->isens_reg[idx], settings[2]);
	if (ret) {
		pr_err("Regulator:isens_vref set load error:%d\n", ret);
		return;
	}
	if (regulator_enable(hw->isens_reg[idx])) {
		pr_err("Failed to enable regulator:isens_vref\n");
		return;
	}
}

static void limits_isens_vref_ldo_init(struct platform_device *pdev,
					struct limits_dcvs_hw *hw)
{
	limits_isens_qref_init(pdev, hw, 0, "isens_vref_1p8",
				"isens-vref-1p8-settings");
	limits_isens_qref_init(pdev, hw, 1, "isens_vref_0p8",
				"isens-vref-0p8-settings");
}

static ssize_t
lmh_freq_limit_show(struct device *dev, struct device_attribute *devattr,
		       char *buf)
{
	struct limits_dcvs_hw *hw = container_of(devattr,
						struct limits_dcvs_hw,
						lmh_freq_attr);

	return scnprintf(buf, PAGE_SIZE, "%lu\n", hw->hw_freq_limit);
}

static int limits_dcvs_probe(struct platform_device *pdev)
{
	int ret;
	int affinity = -1;
	struct limits_dcvs_hw *hw;
	struct device_node *dn = pdev->dev.of_node;
	struct device_node *cpu_node, *lmh_node;
	uint32_t request_reg, clear_reg;
	int cpu, idx = 0;
	cpumask_t mask = { CPU_BITS_NONE };
	const __be32 *addr;

	for_each_possible_cpu(cpu) {
		cpu_node = of_cpu_device_node_get(cpu);
		if (!cpu_node)
			continue;
		lmh_node = of_parse_phandle(cpu_node, "qcom,lmh-dcvs", 0);
		if (lmh_node == dn) {
			/*set the cpumask*/
			cpumask_set_cpu(cpu, &(mask));
		}
		of_node_put(cpu_node);
		of_node_put(lmh_node);
	}

	hw = devm_kzalloc(&pdev->dev, sizeof(*hw), GFP_KERNEL);
	if (!hw)
		return -ENOMEM;
	/*
	 * We just init regulator if none of the CPUs have
	 * reference to our LMH node
	 */
	if (cpumask_empty(&mask)) {
		limits_isens_vref_ldo_init(pdev, hw);
		mutex_lock(&lmh_dcvs_list_access);
		INIT_LIST_HEAD(&hw->list);
		list_add_tail(&hw->list, &lmh_dcvs_hw_list);
		mutex_unlock(&lmh_dcvs_list_access);
		return 0;
	}

	hw->cdev_data = devm_kcalloc(&pdev->dev, cpumask_weight(&mask),
				   sizeof(*hw->cdev_data),
				   GFP_KERNEL);
	if (!hw->cdev_data)
		return -ENOMEM;

	cpumask_copy(&hw->core_map, &mask);
	hw->cdev_registered = 0;
	for_each_cpu(cpu, &hw->core_map) {
		hw->cdev_data[idx].cdev = NULL;
		hw->cdev_data[idx].max_freq = U32_MAX;
		hw->max_freq[idx] = U32_MAX;
		idx++;
	}
	ret = of_property_read_u32(dn, "qcom,affinity", &affinity);
	if (ret)
		return -ENODEV;
	switch (affinity) {
	case 0:
		hw->affinity = LIMITS_CLUSTER_0;
		break;
	case 1:
		hw->affinity = LIMITS_CLUSTER_1;
		break;
	default:
		return -EINVAL;
	}

	addr = of_get_address(dn, 0, NULL, NULL);
	if (!addr) {
		pr_err("Property llm-base-addr not found\n");
		return -EINVAL;
	}
	clear_reg = be32_to_cpu(addr[0]) + LIMITS_CLUSTER_INT_CLR_OFFSET;
	addr = of_get_address(dn, 1, NULL, NULL);
	if (!addr) {
		pr_err("Property osm-base-addr not found\n");
		return -EINVAL;
	}
	request_reg = be32_to_cpu(addr[0]) + LIMITS_CLUSTER_REQ_OFFSET;

	hw->hw_freq_limit = U32_MAX;
	snprintf(hw->sensor_name, sizeof(hw->sensor_name), "limits_sensor-%02d",
			affinity);

	mutex_init(&hw->access_lock);
	INIT_DEFERRABLE_WORK(&hw->freq_poll_work, limits_dcvs_poll);
	hw->osm_hw_reg = devm_ioremap(&pdev->dev, request_reg, 0x4);
	if (!hw->osm_hw_reg) {
		pr_err("register remap failed\n");
		goto probe_exit;
	}
	hw->int_clr_reg = devm_ioremap(&pdev->dev, clear_reg, 0x4);
	if (!hw->int_clr_reg) {
		pr_err("interrupt clear reg remap failed\n");
		goto probe_exit;
	}

	hw->irq_num = of_irq_get(pdev->dev.of_node, 0);
	if (hw->irq_num < 0) {
		pr_err("Error getting IRQ number. err:%d\n", hw->irq_num);
		goto probe_exit;
	}
	hw->is_irq_enabled = true;
	ret = devm_request_threaded_irq(&pdev->dev, hw->irq_num, NULL,
		lmh_dcvs_handle_isr, IRQF_TRIGGER_HIGH | IRQF_ONESHOT
		| IRQF_NO_SUSPEND | IRQF_SHARED, hw->sensor_name, hw);
	if (ret) {
		pr_err("Error registering for irq. err:%d\n", ret);
		ret = 0;
		goto probe_exit;
	}
	limits_isens_vref_ldo_init(pdev, hw);
	sysfs_attr_init(&hw->lmh_freq_attr.attr);
	hw->lmh_freq_attr.attr.name = "lmh_freq_limit";
	hw->lmh_freq_attr.show = lmh_freq_limit_show;
	hw->lmh_freq_attr.attr.mode = 0444;
	device_create_file(&pdev->dev, &hw->lmh_freq_attr);

probe_exit:
	mutex_lock(&lmh_dcvs_list_access);
	INIT_LIST_HEAD(&hw->list);
	list_add_tail(&hw->list, &lmh_dcvs_hw_list);
	mutex_unlock(&lmh_dcvs_list_access);

	return ret;
}

static const struct of_device_id limits_dcvs_match[] = {
	{ .compatible = "qcom,msm-hw-limits", },
	{},
};

static struct platform_driver limits_dcvs_driver = {
	.probe		= limits_dcvs_probe,
	.driver		= {
		.name = KBUILD_MODNAME,
		.of_match_table = limits_dcvs_match,
	},
};
builtin_platform_driver(limits_dcvs_driver);
MODULE_LICENSE("GPL");