// SPDX-License-Identifier: GPL-2.0+
/*
 * Ingenic JZ47xx remoteproc driver
 * Copyright 2019, Paul Cercueil <paul@crapouillou.net>
 */

#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/remoteproc.h>

#include "remoteproc_internal.h"

#define REG_AUX_CTRL            0x0
#define REG_AUX_MSG_ACK         0x10
#define REG_AUX_MSG             0x14
#define REG_CORE_MSG_ACK        0x18
#define REG_CORE_MSG            0x1C

#define AUX_CTRL_SLEEP          BIT(31)
#define AUX_CTRL_MSG_IRQ_EN     BIT(3)
#define AUX_CTRL_NMI_RESETS     BIT(2)
#define AUX_CTRL_NMI            BIT(1)
#define AUX_CTRL_SW_RESET       BIT(0)

static bool auto_boot;
module_param(auto_boot, bool, 0400);
MODULE_PARM_DESC(auto_boot,
                 "Auto-boot the remote processor [default=false]");

struct vpu_mem_map {
        const char *name;
        unsigned int da;
};

struct vpu_mem_info {
        const struct vpu_mem_map *map;
        unsigned long len;
        void __iomem *base;
};

static const struct vpu_mem_map vpu_mem_map[] = {
        { "tcsm0", 0x132b0000 },
        { "tcsm1", 0xf4000000 },
        { "sram",  0x132f0000 },
};

/**
 * struct vpu - Ingenic VPU remoteproc private structure
 * @irq: interrupt number
 * @clks: pointers to the VPU and AUX clocks
 * @aux_base: raw pointer to the AUX interface registers
 * @mem_info: array of struct vpu_mem_info, which contain the mapping info of
 *            each of the external memories
 * @dev: private pointer to the device
 */
struct vpu {
        int irq;
        struct clk_bulk_data clks[2];
        void __iomem *aux_base;
        struct vpu_mem_info mem_info[ARRAY_SIZE(vpu_mem_map)];
        struct device *dev;
};

static int ingenic_rproc_prepare(struct rproc *rproc)
{
        struct vpu *vpu = rproc->priv;
        int ret;

        /* The clocks must be enabled for the firmware to be loaded in TCSM */
        ret = clk_bulk_prepare_enable(ARRAY_SIZE(vpu->clks), vpu->clks);
        if (ret)
                dev_err(vpu->dev, "Unable to start clocks: %d\n", ret);

        return ret;
}

static int ingenic_rproc_unprepare(struct rproc *rproc)
{
        struct vpu *vpu = rproc->priv;

        clk_bulk_disable_unprepare(ARRAY_SIZE(vpu->clks), vpu->clks);

        return 0;
}

static int ingenic_rproc_start(struct rproc *rproc)
{
        struct vpu *vpu = rproc->priv;
        u32 ctrl;

        enable_irq(vpu->irq);

        /* Reset the AUX and enable message IRQ */
        ctrl = AUX_CTRL_NMI_RESETS | AUX_CTRL_NMI | AUX_CTRL_MSG_IRQ_EN;
        writel(ctrl, vpu->aux_base + REG_AUX_CTRL);

        return 0;
}

static int ingenic_rproc_stop(struct rproc *rproc)
{
        struct vpu *vpu = rproc->priv;

        disable_irq(vpu->irq);

        /* Keep AUX in reset mode */
        writel(AUX_CTRL_SW_RESET, vpu->aux_base + REG_AUX_CTRL);

        return 0;
}

static void ingenic_rproc_kick(struct rproc *rproc, int vqid)
{
        struct vpu *vpu = rproc->priv;

        writel(vqid, vpu->aux_base + REG_CORE_MSG);
}

static void *ingenic_rproc_da_to_va(struct rproc *rproc, u64 da, size_t len, bool *is_iomem)
{
        struct vpu *vpu = rproc->priv;
        void __iomem *va = NULL;
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(vpu_mem_map); i++) {
                const struct vpu_mem_info *info = &vpu->mem_info[i];
                const struct vpu_mem_map *map = info->map;

                if (da >= map->da && (da + len) < (map->da + info->len)) {
                        va = info->base + (da - map->da);
                        break;
                }
        }

        return (__force void *)va;
}

static const struct rproc_ops ingenic_rproc_ops = {
        .prepare = ingenic_rproc_prepare,
        .unprepare = ingenic_rproc_unprepare,
        .start = ingenic_rproc_start,
        .stop = ingenic_rproc_stop,
        .kick = ingenic_rproc_kick,
        .da_to_va = ingenic_rproc_da_to_va,
};

static irqreturn_t vpu_interrupt(int irq, void *data)
{
        struct rproc *rproc = data;
        struct vpu *vpu = rproc->priv;
        u32 vring;

        vring = readl(vpu->aux_base + REG_AUX_MSG);

        /* Ack the interrupt */
        writel(0, vpu->aux_base + REG_AUX_MSG_ACK);

        return rproc_vq_interrupt(rproc, vring);
}

static int ingenic_rproc_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct resource *mem;
        struct rproc *rproc;
        struct vpu *vpu;
        unsigned int i;
        int ret;

        rproc = devm_rproc_alloc(dev, "ingenic-vpu",
                                 &ingenic_rproc_ops, NULL, sizeof(*vpu));
        if (!rproc)
                return -ENOMEM;

        rproc->auto_boot = auto_boot;

        vpu = rproc->priv;
        vpu->dev = &pdev->dev;
        platform_set_drvdata(pdev, vpu);

        vpu->aux_base = devm_platform_ioremap_resource_byname(pdev, "aux");
        if (IS_ERR(vpu->aux_base)) {
                dev_err(dev, "Failed to ioremap\n");
                return PTR_ERR(vpu->aux_base);
        }

        for (i = 0; i < ARRAY_SIZE(vpu_mem_map); i++) {
                mem = platform_get_resource_byname(pdev, IORESOURCE_MEM,
                                                   vpu_mem_map[i].name);

                vpu->mem_info[i].base = devm_ioremap_resource(dev, mem);
                if (IS_ERR(vpu->mem_info[i].base)) {
                        ret = PTR_ERR(vpu->mem_info[i].base);
                        dev_err(dev, "Failed to ioremap\n");
                        return ret;
                }

                vpu->mem_info[i].len = resource_size(mem);
                vpu->mem_info[i].map = &vpu_mem_map[i];
        }

        vpu->clks[0].id = "vpu";
        vpu->clks[1].id = "aux";

        ret = devm_clk_bulk_get(dev, ARRAY_SIZE(vpu->clks), vpu->clks);
        if (ret) {
                dev_err(dev, "Failed to get clocks\n");
                return ret;
        }

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

        ret = devm_request_irq(dev, vpu->irq, vpu_interrupt, IRQF_NO_AUTOEN,
                               "VPU", rproc);
        if (ret < 0) {
                dev_err(dev, "Failed to request IRQ\n");
                return ret;
        }

        ret = devm_rproc_add(dev, rproc);
        if (ret) {
                dev_err(dev, "Failed to register remote processor\n");
                return ret;
        }

        return 0;
}

static const struct of_device_id ingenic_rproc_of_matches[] = {
        { .compatible = "ingenic,jz4770-vpu-rproc", },
        {}
};
MODULE_DEVICE_TABLE(of, ingenic_rproc_of_matches);

static struct platform_driver ingenic_rproc_driver = {
        .probe = ingenic_rproc_probe,
        .driver = {
                .name = "ingenic-vpu",
                .of_match_table = ingenic_rproc_of_matches,
        },
};
module_platform_driver(ingenic_rproc_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>");
MODULE_DESCRIPTION("Ingenic JZ47xx Remote Processor control driver");