// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2021 Western Digital Corporation or its affiliates.
 * Copyright (C) 2022 Ventana Micro Systems Inc.
 */

#include <linux/bitfield.h>
#include <linux/irqchip/riscv-aplic.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/printk.h>

#include "irq-riscv-aplic-main.h"

void aplic_irq_unmask(struct irq_data *d)
{
	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);

	writel(d->hwirq, priv->regs + APLIC_SETIENUM);
}

void aplic_irq_mask(struct irq_data *d)
{
	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);

	writel(d->hwirq, priv->regs + APLIC_CLRIENUM);
}

int aplic_irq_set_type(struct irq_data *d, unsigned int type)
{
	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
	void __iomem *sourcecfg;
	u32 val = 0;

	switch (type) {
	case IRQ_TYPE_NONE:
		val = APLIC_SOURCECFG_SM_INACTIVE;
		break;
	case IRQ_TYPE_LEVEL_LOW:
		val = APLIC_SOURCECFG_SM_LEVEL_LOW;
		break;
	case IRQ_TYPE_LEVEL_HIGH:
		val = APLIC_SOURCECFG_SM_LEVEL_HIGH;
		break;
	case IRQ_TYPE_EDGE_FALLING:
		val = APLIC_SOURCECFG_SM_EDGE_FALL;
		break;
	case IRQ_TYPE_EDGE_RISING:
		val = APLIC_SOURCECFG_SM_EDGE_RISE;
		break;
	default:
		return -EINVAL;
	}

	sourcecfg = priv->regs + APLIC_SOURCECFG_BASE;
	sourcecfg += (d->hwirq - 1) * sizeof(u32);
	writel(val, sourcecfg);

	return 0;
}

int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
			      unsigned long *hwirq, unsigned int *type)
{
	if (WARN_ON(fwspec->param_count < 2))
		return -EINVAL;
	if (WARN_ON(!fwspec->param[0]))
		return -EINVAL;

	/* For DT, gsi_base is always zero. */
	*hwirq = fwspec->param[0] - gsi_base;
	*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;

	WARN_ON(*type == IRQ_TYPE_NONE);

	return 0;
}

void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode)
{
	u32 val;
#ifdef CONFIG_RISCV_M_MODE
	u32 valh;

	if (msi_mode) {
		val = lower_32_bits(priv->msicfg.base_ppn);
		valh = FIELD_PREP(APLIC_xMSICFGADDRH_BAPPN, upper_32_bits(priv->msicfg.base_ppn));
		valh |= FIELD_PREP(APLIC_xMSICFGADDRH_LHXW, priv->msicfg.lhxw);
		valh |= FIELD_PREP(APLIC_xMSICFGADDRH_HHXW, priv->msicfg.hhxw);
		valh |= FIELD_PREP(APLIC_xMSICFGADDRH_LHXS, priv->msicfg.lhxs);
		valh |= FIELD_PREP(APLIC_xMSICFGADDRH_HHXS, priv->msicfg.hhxs);
		writel(val, priv->regs + APLIC_xMSICFGADDR);
		writel(valh, priv->regs + APLIC_xMSICFGADDRH);
	}
#endif

	/* Setup APLIC domaincfg register */
	val = readl(priv->regs + APLIC_DOMAINCFG);
	val |= APLIC_DOMAINCFG_IE;
	if (msi_mode)
		val |= APLIC_DOMAINCFG_DM;
	writel(val, priv->regs + APLIC_DOMAINCFG);
	if (readl(priv->regs + APLIC_DOMAINCFG) != val)
		dev_warn(priv->dev, "unable to write 0x%x in domaincfg\n", val);
}

static void aplic_init_hw_irqs(struct aplic_priv *priv)
{
	int i;

	/* Disable all interrupts */
	for (i = 0; i <= priv->nr_irqs; i += 32)
		writel(-1U, priv->regs + APLIC_CLRIE_BASE + (i / 32) * sizeof(u32));

	/* Set interrupt type and default priority for all interrupts */
	for (i = 1; i <= priv->nr_irqs; i++) {
		writel(0, priv->regs + APLIC_SOURCECFG_BASE + (i - 1) * sizeof(u32));
		writel(APLIC_DEFAULT_PRIORITY,
		       priv->regs + APLIC_TARGET_BASE + (i - 1) * sizeof(u32));
	}

	/* Clear APLIC domaincfg */
	writel(0, priv->regs + APLIC_DOMAINCFG);
}

int aplic_setup_priv(struct aplic_priv *priv, struct device *dev, void __iomem *regs)
{
	struct device_node *np = to_of_node(dev->fwnode);
	struct of_phandle_args parent;
	int rc;

	/*
	 * Currently, only OF fwnode is supported so extend this
	 * function for ACPI support.
	 */
	if (!np)
		return -EINVAL;

	/* Save device pointer and register base */
	priv->dev = dev;
	priv->regs = regs;

	/* Find out number of interrupt sources */
	rc = of_property_read_u32(np, "riscv,num-sources", &priv->nr_irqs);
	if (rc) {
		dev_err(dev, "failed to get number of interrupt sources\n");
		return rc;
	}

	/*
	 * Find out number of IDCs based on parent interrupts
	 *
	 * If "msi-parent" property is present then we ignore the
	 * APLIC IDCs which forces the APLIC driver to use MSI mode.
	 */
	if (!of_property_present(np, "msi-parent")) {
		while (!of_irq_parse_one(np, priv->nr_idcs, &parent))
			priv->nr_idcs++;
	}

	/* Setup initial state APLIC interrupts */
	aplic_init_hw_irqs(priv);

	return 0;
}

static int aplic_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	bool msi_mode = false;
	void __iomem *regs;
	int rc;

	/* Map the MMIO registers */
	regs = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(regs)) {
		dev_err(dev, "failed map MMIO registers\n");
		return PTR_ERR(regs);
	}

	/*
	 * If msi-parent property is present then setup APLIC MSI
	 * mode otherwise setup APLIC direct mode.
	 */
	msi_mode = of_property_present(to_of_node(dev->fwnode), "msi-parent");
	if (msi_mode)
		rc = aplic_msi_setup(dev, regs);
	else
		rc = aplic_direct_setup(dev, regs);
	if (rc)
		dev_err(dev, "failed to setup APLIC in %s mode\n", msi_mode ? "MSI" : "direct");

	return rc;
}

static const struct of_device_id aplic_match[] = {
	{ .compatible = "riscv,aplic" },
	{}
};

static struct platform_driver aplic_driver = {
	.driver = {
		.name		= "riscv-aplic",
		.of_match_table	= aplic_match,
	},
	.probe = aplic_probe,
};
builtin_platform_driver(aplic_driver);