// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2021 MediaTek Inc.
 * Author: Yuan Jung Kuo <yuan-jung.kuo@mediatek.com>
 */

#include <linux/io.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/regulator/consumer.h>
#include <linux/delay.h>
#include <linux/irqflags.h>

#define ISPDVFS_DBG
#ifdef ISPDVFS_DBG
#define ISP_LOGD(fmt, args...) \
	do { \
		if (mtk_ispdvfs_dbg_level) \
			pr_notice("[ISPDVFS] %s(): " fmt "\n",\
				__func__, ##args); \
	} while (0)
#else
#define ISPDVFS_DBG(fmt, args...)
#endif
#define ISP_LOGI(fmt, args...) \
	pr_notice("[ISPDVFS] %s(): " fmt "\n", \
		__func__, ##args)
#define ISP_LOGE(fmt, args...) \
	pr_notice("[ISPDVFS] error %s(),%d: " fmt "\n", \
		__func__, __LINE__, ##args)
#define ISP_LOGF(fmt, args...) \
	pr_notice("[ISPDVFS] fatal %s(),%d: " fmt "\n", \
		__func__, __LINE__, ##args)

#define SPM_VMM_HW_SEM_REG_OFST 0x6A8
#define SPM_VMM_ISO_REG_OFST 0xF30
#define SPM_VMM_ISO_REG_OFST_MT6886 0xF74
#define SPM_VMM_EXT_BUCK_ISO_BIT 16
#define SPM_AOC_VMM_SRAM_ISO_DIN_BIT 17
#define SPM_AOC_VMM_SRAM_LATCH_ENB 18
#define SPM_HW_SEM_TIMEOUT_RUN 5000
#define SPM_HW_SEM_SET_DELAY_US 10

#define SPM_VMM_HW_SEM_REG_OFST_M0 0x69C
#define SPM_VMM_HW_SEM_REG_OFST_M1 0x6A0
#define SPM_VMM_HW_SEM_REG_OFST_M2 0x6A4
#define SPM_VMM_HW_SEM_REG_OFST_M3 0x6A8
#define SPM_VMM_HW_SEM_REG_OFST_M4 0x6AC
#define SPM_VMM_HW_SEM_REG_OFST_M5 0x6B0
#define SPM_VMM_HW_SEM_REG_OFST_M6 0x6B4
#define SPM_VMM_HW_SEM_REG_OFST_M7 0x6B8

/* Buck ISO control for 7s */
#define SPM_VMM_EXT_BUCK_ISO_BIT_7S 20
#define SPM_AOC_VMM_SRAM_ISO_DIN_BIT_7S 21
#define SPM_AOC_VMM_SRAM_LATCH_ENB_7S 22
#define SOC_BUCK_ISO_CON_SET 0xF7C
#define SOC_BUCK_ISO_CON_CLR 0xF80

struct vmm_spm_drv_data {
	void __iomem *spm_reg;
	struct notifier_block nb;
};

static struct vmm_spm_drv_data g_drv_data;

static void vmm_dump_spm_sem_reg(void __iomem *base)
{
	ISP_LOGE("SPM_VMM_HW_SEM_REG_OFST_M0 0x(%x)\n",
			readl_relaxed(base + SPM_VMM_HW_SEM_REG_OFST_M0));
	ISP_LOGE("SPM_VMM_HW_SEM_REG_OFST_M1 0x(%x)\n",
			readl_relaxed(base + SPM_VMM_HW_SEM_REG_OFST_M1));
	ISP_LOGE("SPM_VMM_HW_SEM_REG_OFST_M2 0x(%x)\n",
			readl_relaxed(base + SPM_VMM_HW_SEM_REG_OFST_M2));
	ISP_LOGE("SPM_VMM_HW_SEM_REG_OFST_M3 0x(%x)\n",
			readl_relaxed(base + SPM_VMM_HW_SEM_REG_OFST_M3));
	ISP_LOGE("SPM_VMM_HW_SEM_REG_OFST_M4 0x(%x)\n",
			readl_relaxed(base + SPM_VMM_HW_SEM_REG_OFST_M4));
	ISP_LOGE("SPM_VMM_HW_SEM_REG_OFST_M5 0x(%x)\n",
			readl_relaxed(base + SPM_VMM_HW_SEM_REG_OFST_M5));
	ISP_LOGE("SPM_VMM_HW_SEM_REG_OFST_M6 0x(%x)\n",
			readl_relaxed(base + SPM_VMM_HW_SEM_REG_OFST_M6));
	ISP_LOGE("SPM_VMM_HW_SEM_REG_OFST_M7 0x(%x)\n",
			readl_relaxed(base + SPM_VMM_HW_SEM_REG_OFST_M7));
}

static int acquire_hw_semaphore(void __iomem *hw_sem_addr, unsigned long *pFlags)
{
	u32 hw_sem;
	int i = 1;
	unsigned long flags;

	ISP_LOGI("VMM will try to acquire hw sem");

	for (;;) {
		local_irq_save(flags);
		hw_sem = readl_relaxed(hw_sem_addr);
		hw_sem |= 0x1;
		writel_relaxed(hw_sem, hw_sem_addr);

		udelay(SPM_HW_SEM_SET_DELAY_US);

		/* *hw_sem_addr == 0x1 means acquire succeed */
		if (readl_relaxed(hw_sem_addr) & 0x1)
			break;

		local_irq_restore(flags);

		if (i++ > SPM_HW_SEM_TIMEOUT_RUN) {
			ISP_LOGE("Acquire HW SEM timeout");
			return -ETIMEDOUT;
		}
	}

	*pFlags = flags;

	return 0;
}

static void release_hw_semaphore(void __iomem *hw_sem_addr, unsigned long *pFlags)
{
	u32 hw_sem;

	hw_sem = readl_relaxed(hw_sem_addr);
	hw_sem |= 0x1;
	writel_relaxed(hw_sem, hw_sem_addr);

	udelay(SPM_HW_SEM_SET_DELAY_US);
	if (readl_relaxed(hw_sem_addr) & 0x1)
		goto error_out;

	local_irq_restore(*pFlags);

	return;

error_out:
	local_irq_restore(*pFlags);
	ISP_LOGE("Release HW SEM FAIL");
	BUG_ON(1);
}

static void vmm_buck_isolation_off(void __iomem *base)
{
	void __iomem *reg_buck_iso_addr = base + SPM_VMM_ISO_REG_OFST;
	void __iomem *hw_sem_addr = base + SPM_VMM_HW_SEM_REG_OFST;
	u32 reg_buck_iso_val;
	unsigned long flags;

	if (acquire_hw_semaphore(hw_sem_addr, &flags)) {
		vmm_dump_spm_sem_reg(base);
		BUG_ON(1);
		return;
	}

	reg_buck_iso_val = readl_relaxed(reg_buck_iso_addr);
	reg_buck_iso_val &= ~(1UL << SPM_VMM_EXT_BUCK_ISO_BIT);
	writel_relaxed(reg_buck_iso_val, reg_buck_iso_addr);

	reg_buck_iso_val = readl_relaxed(reg_buck_iso_addr);
	reg_buck_iso_val &= ~(1UL << SPM_AOC_VMM_SRAM_ISO_DIN_BIT);
	writel_relaxed(reg_buck_iso_val, reg_buck_iso_addr);

	reg_buck_iso_val = readl_relaxed(reg_buck_iso_addr);
	reg_buck_iso_val &= ~(1UL << SPM_AOC_VMM_SRAM_LATCH_ENB);
	writel_relaxed(reg_buck_iso_val, reg_buck_iso_addr);

	release_hw_semaphore(hw_sem_addr, &flags);
}

static void vmm_buck_isolation_on(void __iomem *base)
{
	void __iomem *reg_buck_iso_addr = base + SPM_VMM_ISO_REG_OFST;
	void __iomem *hw_sem_addr = base + SPM_VMM_HW_SEM_REG_OFST;
	u32 reg_buck_iso_val;
	unsigned long flags;

	if (acquire_hw_semaphore(hw_sem_addr, &flags)) {
		vmm_dump_spm_sem_reg(base);
		BUG_ON(1);
		return;
	}

	reg_buck_iso_val = readl_relaxed(reg_buck_iso_addr);
	reg_buck_iso_val |= (1UL << SPM_AOC_VMM_SRAM_LATCH_ENB);
	writel_relaxed(reg_buck_iso_val, reg_buck_iso_addr);

	reg_buck_iso_val = readl_relaxed(reg_buck_iso_addr);
	reg_buck_iso_val |= (1UL << SPM_AOC_VMM_SRAM_ISO_DIN_BIT);
	writel_relaxed(reg_buck_iso_val, reg_buck_iso_addr);

	reg_buck_iso_val = readl_relaxed(reg_buck_iso_addr);
	reg_buck_iso_val |= (1UL << SPM_VMM_EXT_BUCK_ISO_BIT);
	writel_relaxed(reg_buck_iso_val, reg_buck_iso_addr);

	release_hw_semaphore(hw_sem_addr, &flags);
}

static int regulator_event_notify(struct notifier_block *nb,
				  unsigned long event, void *data)
{
	struct vmm_spm_drv_data *drv_data = &g_drv_data;

	if (!drv_data->spm_reg) {
		ISP_LOGE("SPM_BASE is NULL");
		return -EINVAL;
	}

	if (event == REGULATOR_EVENT_ENABLE) {
		vmm_buck_isolation_off(drv_data->spm_reg);
		ISP_LOGI("VMM regulator enable done");
	} else if (event == REGULATOR_EVENT_PRE_DISABLE) {
		vmm_buck_isolation_on(drv_data->spm_reg);
		ISP_LOGI("VMM regulator before disable");
	}

	return 0;
}

static void vmm_buck_isolation_off_mt6886(void __iomem *base)
{
	void __iomem *reg_buck_iso_addr = base + SPM_VMM_ISO_REG_OFST_MT6886;
	void __iomem *hw_sem_addr = base + SPM_VMM_HW_SEM_REG_OFST;
	u32 reg_buck_iso_val;
	unsigned long flags;

	if (acquire_hw_semaphore(hw_sem_addr, &flags)) {
		vmm_dump_spm_sem_reg(base);
		BUG_ON(1);
		return;
	}

	reg_buck_iso_val = readl_relaxed(reg_buck_iso_addr);
	reg_buck_iso_val &= ~(1UL << SPM_VMM_EXT_BUCK_ISO_BIT_7S);
	writel_relaxed(reg_buck_iso_val, reg_buck_iso_addr);

	reg_buck_iso_val = readl_relaxed(reg_buck_iso_addr);
	reg_buck_iso_val &= ~(1UL << SPM_AOC_VMM_SRAM_ISO_DIN_BIT_7S);
	writel_relaxed(reg_buck_iso_val, reg_buck_iso_addr);

	reg_buck_iso_val = readl_relaxed(reg_buck_iso_addr);
	reg_buck_iso_val &= ~(1UL << SPM_AOC_VMM_SRAM_LATCH_ENB_7S);
	writel_relaxed(reg_buck_iso_val, reg_buck_iso_addr);

	release_hw_semaphore(hw_sem_addr, &flags);
}

static void vmm_buck_isolation_on_mt6886(void __iomem *base)
{
	void __iomem *reg_buck_iso_addr = base + SPM_VMM_ISO_REG_OFST_MT6886;
	void __iomem *hw_sem_addr = base + SPM_VMM_HW_SEM_REG_OFST;
	u32 reg_buck_iso_val;
	unsigned long flags;

	if (acquire_hw_semaphore(hw_sem_addr, &flags)) {
		vmm_dump_spm_sem_reg(base);
		BUG_ON(1);
		return;
	}

	reg_buck_iso_val = readl_relaxed(reg_buck_iso_addr);
	reg_buck_iso_val |= (1UL << SPM_AOC_VMM_SRAM_LATCH_ENB_7S);
	writel_relaxed(reg_buck_iso_val, reg_buck_iso_addr);

	reg_buck_iso_val = readl_relaxed(reg_buck_iso_addr);
	reg_buck_iso_val |= (1UL << SPM_AOC_VMM_SRAM_ISO_DIN_BIT_7S);
	writel_relaxed(reg_buck_iso_val, reg_buck_iso_addr);

	reg_buck_iso_val = readl_relaxed(reg_buck_iso_addr);
	reg_buck_iso_val |= (1UL << SPM_VMM_EXT_BUCK_ISO_BIT_7S);
	writel_relaxed(reg_buck_iso_val, reg_buck_iso_addr);

	release_hw_semaphore(hw_sem_addr, &flags);
}

static int regulator_event_notify_mt6886(struct notifier_block *nb,
				  unsigned long event, void *data)
{
	struct vmm_spm_drv_data *drv_data = &g_drv_data;

	if (!drv_data->spm_reg) {
		ISP_LOGE("SPM_BASE is NULL");
		return -EINVAL;
	}

	if (event == REGULATOR_EVENT_ENABLE) {
		vmm_buck_isolation_off_mt6886(drv_data->spm_reg);
		ISP_LOGI("VMM regulator enable done");
	} else if (event == REGULATOR_EVENT_PRE_DISABLE) {
		vmm_buck_isolation_on_mt6886(drv_data->spm_reg);
		ISP_LOGI("VMM regulator before disable");
	}

	return 0;
}

static void vmm_buck_isolation_off_7s(void __iomem *base)
{
	void __iomem *addr = base + SOC_BUCK_ISO_CON_CLR;

	writel_relaxed((1 << SPM_VMM_EXT_BUCK_ISO_BIT_7S), addr);
	writel_relaxed((1 << SPM_AOC_VMM_SRAM_ISO_DIN_BIT_7S), addr);
	writel_relaxed((1 << SPM_AOC_VMM_SRAM_LATCH_ENB_7S), addr);
}

static void vmm_buck_isolation_on_7s(void __iomem *base)
{
	void __iomem *addr = base + SOC_BUCK_ISO_CON_SET;

	writel_relaxed((1 << SPM_AOC_VMM_SRAM_LATCH_ENB_7S), addr);
	writel_relaxed((1 << SPM_AOC_VMM_SRAM_ISO_DIN_BIT_7S), addr);
	writel_relaxed((1 << SPM_VMM_EXT_BUCK_ISO_BIT_7S), addr);
}

static int regulator_event_notify_7s(struct notifier_block *nb,
				  unsigned long event, void *data)
{
	struct vmm_spm_drv_data *drv_data = &g_drv_data;

	if (!drv_data->spm_reg) {
		ISP_LOGE("SPM_BASE is NULL");
		return -EINVAL;
	}

	if (event == REGULATOR_EVENT_ENABLE) {
		vmm_buck_isolation_off_7s(drv_data->spm_reg);
		ISP_LOGI("VMM 7s regulator enable done");
	} else if (event == REGULATOR_EVENT_PRE_DISABLE) {
		vmm_buck_isolation_on_7s(drv_data->spm_reg);
		ISP_LOGI("VMM 7s regulator before disable");
	}

	return 0;
}

static int vmm_spm_probe(struct platform_device *pdev)
{
	struct vmm_spm_drv_data *drv_data = &g_drv_data;
	struct device *dev = &pdev->dev;
	struct resource *res;
	struct regulator *reg;
	s32 ret;

	/* SPM registers */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		ISP_LOGE("fail to get resource SPM_BASE");
		return -EINVAL;
	}

	drv_data->spm_reg = devm_ioremap(dev, res->start, resource_size(res));
	if (!(drv_data->spm_reg)) {
		ISP_LOGE("fail to ioremap SPM_BASE: 0x%llx", res->start);
		return -EINVAL;
	}

	reg = devm_regulator_get(dev, "vmm-pmic");
	if (IS_ERR(reg)) {
		ISP_LOGE("devm_regulator_get vmm-pmic fail");
		return PTR_ERR(reg);
	}

	if (of_device_is_compatible(dev->of_node, "mediatek,vmm_spm_7s"))
		drv_data->nb.notifier_call = regulator_event_notify_7s;
	else if (of_device_is_compatible(dev->of_node, "mediatek,vmm_spm_mt6886"))
		drv_data->nb.notifier_call = regulator_event_notify_mt6886;
	else
		drv_data->nb.notifier_call = regulator_event_notify;
	ret = devm_regulator_register_notifier(reg, &drv_data->nb);
	if (ret)
		ISP_LOGE("Failed to register notifier: %d\n", ret);

	return ret;
}

static const struct of_device_id of_vmm_spm_match_tbl[] = {
	{
		.compatible = "mediatek,vmm_spm",
	},
	{
		.compatible = "mediatek,vmm_spm_7s",
	},
	{
		.compatible = "mediatek,vmm_spm_mt6886",
	},
	{}
};

static struct platform_driver drv_vmm_spm = {
	.probe = vmm_spm_probe,
	.driver = {
		.name = "mtk-vmm-spm",
		.of_match_table = of_vmm_spm_match_tbl,
	},
};

static int __init mtk_vmm_spm_init(void)
{
	s32 status;

	status = platform_driver_register(&drv_vmm_spm);
	if (status) {
		pr_notice("Failed to register VMM SPM driver(%d)\n", status);
		return -ENODEV;
	}
	return 0;
}

static void __exit mtk_vmm_spm_exit(void)
{
	platform_driver_unregister(&drv_vmm_spm);
}

module_init(mtk_vmm_spm_init);
module_exit(mtk_vmm_spm_exit);
MODULE_DESCRIPTION("MTK VMM SPM driver");
MODULE_AUTHOR("Yuan Jung Kuo <yuan-jung.kuo@mediatek.com>");
MODULE_LICENSE("GPL v2");