// SPDX-License-Identifier: GPL-2.0-only
/*
 * TI AMx3 Wakeup M3 Remote Processor driver
 *
 * Copyright (C) 2014-2015 Texas Instruments, Inc.
 *
 * Dave Gerlach <d-gerlach@ti.com>
 * Suman Anna <s-anna@ti.com>
 */

#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/remoteproc.h>
#include <linux/reset.h>

#include <linux/platform_data/wkup_m3.h>

#include "remoteproc_internal.h"

#define WKUPM3_MEM_MAX  2

/**
 * struct wkup_m3_mem - WkupM3 internal memory structure
 * @cpu_addr: MPU virtual address of the memory region
 * @bus_addr: Bus address used to access the memory region
 * @dev_addr: Device address from Wakeup M3 view
 * @size: Size of the memory region
 */
struct wkup_m3_mem {
        void __iomem *cpu_addr;
        phys_addr_t bus_addr;
        u32 dev_addr;
        size_t size;
};

/**
 * struct wkup_m3_rproc - WkupM3 remote processor state
 * @rproc: rproc handle
 * @pdev: pointer to platform device
 * @mem: WkupM3 memory information
 * @rsts: reset control
 */
struct wkup_m3_rproc {
        struct rproc *rproc;
        struct platform_device *pdev;
        struct wkup_m3_mem mem[WKUPM3_MEM_MAX];
        struct reset_control *rsts;
};

static int wkup_m3_rproc_start(struct rproc *rproc)
{
        struct wkup_m3_rproc *wkupm3 = rproc->priv;
        struct platform_device *pdev = wkupm3->pdev;
        struct device *dev = &pdev->dev;
        struct wkup_m3_platform_data *pdata = dev_get_platdata(dev);
        int error = 0;

        error = reset_control_deassert(wkupm3->rsts);

        if (!wkupm3->rsts && pdata->deassert_reset(pdev, pdata->reset_name)) {
                dev_err(dev, "Unable to reset wkup_m3!\n");
                error = -ENODEV;
        }

        return error;
}

static int wkup_m3_rproc_stop(struct rproc *rproc)
{
        struct wkup_m3_rproc *wkupm3 = rproc->priv;
        struct platform_device *pdev = wkupm3->pdev;
        struct device *dev = &pdev->dev;
        struct wkup_m3_platform_data *pdata = dev_get_platdata(dev);
        int error = 0;

        error = reset_control_assert(wkupm3->rsts);

        if (!wkupm3->rsts && pdata->assert_reset(pdev, pdata->reset_name)) {
                dev_err(dev, "Unable to assert reset of wkup_m3!\n");
                error = -ENODEV;
        }

        return error;
}

static void *wkup_m3_rproc_da_to_va(struct rproc *rproc, u64 da, size_t len, bool *is_iomem)
{
        struct wkup_m3_rproc *wkupm3 = rproc->priv;
        void *va = NULL;
        int i;
        u32 offset;

        if (len == 0)
                return NULL;

        for (i = 0; i < WKUPM3_MEM_MAX; i++) {
                if (da >= wkupm3->mem[i].dev_addr && da + len <=
                    wkupm3->mem[i].dev_addr +  wkupm3->mem[i].size) {
                        offset = da -  wkupm3->mem[i].dev_addr;
                        /* __force to make sparse happy with type conversion */
                        va = (__force void *)(wkupm3->mem[i].cpu_addr + offset);
                        break;
                }
        }

        return va;
}

static const struct rproc_ops wkup_m3_rproc_ops = {
        .start          = wkup_m3_rproc_start,
        .stop           = wkup_m3_rproc_stop,
        .da_to_va       = wkup_m3_rproc_da_to_va,
};

static const struct of_device_id wkup_m3_rproc_of_match[] = {
        { .compatible = "ti,am3352-wkup-m3", },
        { .compatible = "ti,am4372-wkup-m3", },
        {},
};
MODULE_DEVICE_TABLE(of, wkup_m3_rproc_of_match);

static void wkup_m3_rproc_pm_runtime_put(void *data)
{
        struct device *dev = data;

        pm_runtime_put_sync(dev);
}

static int wkup_m3_rproc_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct wkup_m3_platform_data *pdata = dev->platform_data;
        /* umem always needs to be processed first */
        const char *mem_names[WKUPM3_MEM_MAX] = { "umem", "dmem" };
        struct wkup_m3_rproc *wkupm3;
        const char *fw_name;
        struct rproc *rproc;
        struct resource *res;
        const __be32 *addrp;
        u32 l4_offset = 0;
        u64 size;
        int ret;
        int i;

        ret = of_property_read_string(dev->of_node, "ti,pm-firmware",
                                      &fw_name);
        if (ret) {
                dev_err(dev, "No firmware filename given\n");
                return -ENODEV;
        }

        ret = devm_pm_runtime_enable(dev);
        if (ret < 0)
                return dev_err_probe(dev, ret, "Failed to enable runtime PM\n");
        ret = pm_runtime_get_sync(&pdev->dev);
        if (ret < 0)
                return dev_err_probe(dev, ret, "pm_runtime_get_sync() failed\n");
        ret = devm_add_action_or_reset(dev, wkup_m3_rproc_pm_runtime_put, dev);
        if (ret)
                return dev_err_probe(dev, ret, "failed to add disable pm devm action\n");

        rproc = devm_rproc_alloc(dev, "wkup_m3", &wkup_m3_rproc_ops,
                                 fw_name, sizeof(*wkupm3));
        if (!rproc)
                return -ENOMEM;

        rproc->auto_boot = false;
        rproc->sysfs_read_only = true;

        wkupm3 = rproc->priv;
        wkupm3->rproc = rproc;
        wkupm3->pdev = pdev;

        wkupm3->rsts = devm_reset_control_get_optional_shared(dev, "rstctrl");
        if (IS_ERR(wkupm3->rsts))
                return PTR_ERR(wkupm3->rsts);
        if (!wkupm3->rsts) {
                if (!(pdata && pdata->deassert_reset && pdata->assert_reset &&
                      pdata->reset_name)) {
                        return dev_err_probe(dev, -ENODEV, "Platform data missing!\n");
                }
        }

        for (i = 0; i < ARRAY_SIZE(mem_names); i++) {
                res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
                                                   mem_names[i]);
                wkupm3->mem[i].cpu_addr = devm_ioremap_resource(dev, res);
                if (IS_ERR(wkupm3->mem[i].cpu_addr))
                        return dev_err_probe(dev, PTR_ERR(wkupm3->mem[i].cpu_addr),
                                             "devm_ioremap_resource failed for resource %d\n", i);
                wkupm3->mem[i].bus_addr = res->start;
                wkupm3->mem[i].size = resource_size(res);
                addrp = of_get_address(dev->of_node, i, &size, NULL);
                /*
                 * The wkupm3 has umem at address 0 in its view, so the device
                 * addresses for each memory region is computed as a relative
                 * offset of the bus address for umem, and therefore needs to be
                 * processed first.
                 */
                if (!strcmp(mem_names[i], "umem"))
                        l4_offset = be32_to_cpu(*addrp);
                wkupm3->mem[i].dev_addr = be32_to_cpu(*addrp) - l4_offset;
        }

        dev_set_drvdata(dev, rproc);

        ret = devm_rproc_add(dev, rproc);
        if (ret)
                return dev_err_probe(dev, ret, "rproc_add failed\n");

        return 0;
}

#ifdef CONFIG_PM
static int wkup_m3_rpm_suspend(struct device *dev)
{
        return -EBUSY;
}

static int wkup_m3_rpm_resume(struct device *dev)
{
        return 0;
}
#endif

static const struct dev_pm_ops wkup_m3_rproc_pm_ops = {
        SET_RUNTIME_PM_OPS(wkup_m3_rpm_suspend, wkup_m3_rpm_resume, NULL)
};

static struct platform_driver wkup_m3_rproc_driver = {
        .probe = wkup_m3_rproc_probe,
        .driver = {
                .name = "wkup_m3_rproc",
                .of_match_table = wkup_m3_rproc_of_match,
                .pm = &wkup_m3_rproc_pm_ops,
        },
};

module_platform_driver(wkup_m3_rproc_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("TI Wakeup M3 remote processor control driver");
MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>");