// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2011-2015, The Linux Foundation. All rights reserved.
 *
 * Description: CoreSight Replicator driver
 */

#include <linux/acpi.h>
#include <linux/amba/bus.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/pm_runtime.h>
#include <linux/property.h>
#include <linux/clk.h>
#include <linux/of.h>
#include <linux/coresight.h>

#include "coresight-priv.h"

#define REPLICATOR_IDFILTER0            0x000
#define REPLICATOR_IDFILTER1            0x004

DEFINE_CORESIGHT_DEVLIST(replicator_devs, "replicator");

/**
 * struct replicator_drvdata - specifics associated to a replicator component
 * @base:       memory mapped base address for this component. Also indicates
 *              whether this one is programmable or not.
 * @atclk:      optional clock for the core parts of the replicator.
 * @pclk:       APB clock if present, otherwise NULL
 * @csdev:      component vitals needed by the framework
 * @spinlock:   serialize enable/disable operations.
 * @check_idfilter_val: check if the context is lost upon clock removal.
 */
struct replicator_drvdata {
        void __iomem            *base;
        struct clk              *atclk;
        struct clk              *pclk;
        struct coresight_device *csdev;
        raw_spinlock_t          spinlock;
        bool                    check_idfilter_val;
};

static void dynamic_replicator_reset(struct replicator_drvdata *drvdata)
{
        struct coresight_device *csdev = drvdata->csdev;

        CS_UNLOCK(drvdata->base);

        if (!coresight_claim_device_unlocked(csdev)) {
                writel_relaxed(0xff, drvdata->base + REPLICATOR_IDFILTER0);
                writel_relaxed(0xff, drvdata->base + REPLICATOR_IDFILTER1);
                coresight_disclaim_device_unlocked(csdev);
        }

        CS_LOCK(drvdata->base);
}

/*
 * replicator_reset : Reset the replicator configuration to sane values.
 */
static void replicator_reset(struct replicator_drvdata *drvdata)
{
        if (drvdata->base)
                dynamic_replicator_reset(drvdata);
}

static int dynamic_replicator_enable(struct replicator_drvdata *drvdata,
                                     int inport, int outport)
{
        int rc = 0;
        u32 id0val, id1val;
        struct coresight_device *csdev = drvdata->csdev;

        CS_UNLOCK(drvdata->base);

        id0val = readl_relaxed(drvdata->base + REPLICATOR_IDFILTER0);
        id1val = readl_relaxed(drvdata->base + REPLICATOR_IDFILTER1);

        /*
         * Some replicator designs lose context when AMBA clocks are removed,
         * so have a check for this.
         */
        if (drvdata->check_idfilter_val && id0val == 0x0 && id1val == 0x0)
                id0val = id1val = 0xff;

        if (id0val == 0xff && id1val == 0xff)
                rc = coresight_claim_device_unlocked(csdev);

        if (!rc) {
                switch (outport) {
                case 0:
                        id0val = 0x0;
                        break;
                case 1:
                        id1val = 0x0;
                        break;
                default:
                        WARN_ON(1);
                        rc = -EINVAL;
                }
        }

        /* Ensure that the outport is enabled. */
        if (!rc) {
                writel_relaxed(id0val, drvdata->base + REPLICATOR_IDFILTER0);
                writel_relaxed(id1val, drvdata->base + REPLICATOR_IDFILTER1);
        }

        CS_LOCK(drvdata->base);

        return rc;
}

static int replicator_enable(struct coresight_device *csdev,
                             struct coresight_connection *in,
                             struct coresight_connection *out)
{
        int rc = 0;
        struct replicator_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
        unsigned long flags;
        bool first_enable = false;

        raw_spin_lock_irqsave(&drvdata->spinlock, flags);
        if (out->src_refcnt == 0) {
                if (drvdata->base)
                        rc = dynamic_replicator_enable(drvdata, in->dest_port,
                                                       out->src_port);
                if (!rc)
                        first_enable = true;
        }
        if (!rc)
                out->src_refcnt++;
        raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);

        if (first_enable)
                dev_dbg(&csdev->dev, "REPLICATOR enabled\n");
        return rc;
}

static void dynamic_replicator_disable(struct replicator_drvdata *drvdata,
                                       int inport, int outport)
{
        u32 reg;
        struct coresight_device *csdev = drvdata->csdev;

        switch (outport) {
        case 0:
                reg = REPLICATOR_IDFILTER0;
                break;
        case 1:
                reg = REPLICATOR_IDFILTER1;
                break;
        default:
                WARN_ON(1);
                return;
        }

        CS_UNLOCK(drvdata->base);

        /* disable the flow of ATB data through port */
        writel_relaxed(0xff, drvdata->base + reg);

        if ((readl_relaxed(drvdata->base + REPLICATOR_IDFILTER0) == 0xff) &&
            (readl_relaxed(drvdata->base + REPLICATOR_IDFILTER1) == 0xff))
                coresight_disclaim_device_unlocked(csdev);
        CS_LOCK(drvdata->base);
}

static void replicator_disable(struct coresight_device *csdev,
                               struct coresight_connection *in,
                               struct coresight_connection *out)
{
        struct replicator_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
        unsigned long flags;
        bool last_disable = false;

        raw_spin_lock_irqsave(&drvdata->spinlock, flags);
        if (--out->src_refcnt == 0) {
                if (drvdata->base)
                        dynamic_replicator_disable(drvdata, in->dest_port,
                                                   out->src_port);
                last_disable = true;
        }
        raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);

        if (last_disable)
                dev_dbg(&csdev->dev, "REPLICATOR disabled\n");
}

static const struct coresight_ops_link replicator_link_ops = {
        .enable         = replicator_enable,
        .disable        = replicator_disable,
};

static const struct coresight_ops replicator_cs_ops = {
        .link_ops       = &replicator_link_ops,
};

static struct attribute *replicator_mgmt_attrs[] = {
        coresight_simple_reg32(idfilter0, REPLICATOR_IDFILTER0),
        coresight_simple_reg32(idfilter1, REPLICATOR_IDFILTER1),
        NULL,
};

static const struct attribute_group replicator_mgmt_group = {
        .attrs = replicator_mgmt_attrs,
        .name = "mgmt",
};

static const struct attribute_group *replicator_groups[] = {
        &replicator_mgmt_group,
        NULL,
};

static int replicator_probe(struct device *dev, struct resource *res)
{
        struct coresight_platform_data *pdata = NULL;
        struct replicator_drvdata *drvdata;
        struct coresight_desc desc = { 0 };
        void __iomem *base;
        int ret;

        if (is_of_node(dev_fwnode(dev)) &&
            of_device_is_compatible(dev->of_node, "arm,coresight-replicator"))
                dev_warn_once(dev,
                              "Uses OBSOLETE CoreSight replicator binding\n");

        desc.name = coresight_alloc_device_name(&replicator_devs, dev);
        if (!desc.name)
                return -ENOMEM;

        drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
        if (!drvdata)
                return -ENOMEM;

        ret = coresight_get_enable_clocks(dev, &drvdata->pclk, &drvdata->atclk);
        if (ret)
                return ret;

        /*
         * Map the device base for dynamic-replicator, which has been
         * validated by AMBA core
         */
        if (res) {
                base = devm_ioremap_resource(dev, res);
                if (IS_ERR(base))
                        return PTR_ERR(base);
                drvdata->base = base;
                desc.groups = replicator_groups;
                desc.access = CSDEV_ACCESS_IOMEM(base);
                coresight_clear_self_claim_tag(&desc.access);
        }

        if (fwnode_property_present(dev_fwnode(dev),
                                    "qcom,replicator-loses-context"))
                drvdata->check_idfilter_val = true;

        dev_set_drvdata(dev, drvdata);

        pdata = coresight_get_platform_data(dev);
        if (IS_ERR(pdata))
                return PTR_ERR(pdata);
        dev->platform_data = pdata;

        raw_spin_lock_init(&drvdata->spinlock);
        desc.type = CORESIGHT_DEV_TYPE_LINK;
        desc.subtype.link_subtype = CORESIGHT_DEV_SUBTYPE_LINK_SPLIT;
        desc.ops = &replicator_cs_ops;
        desc.pdata = dev->platform_data;
        desc.dev = dev;

        drvdata->csdev = coresight_register(&desc);
        if (IS_ERR(drvdata->csdev))
                return PTR_ERR(drvdata->csdev);

        replicator_reset(drvdata);
        return 0;
}

static int replicator_remove(struct device *dev)
{
        struct replicator_drvdata *drvdata = dev_get_drvdata(dev);

        coresight_unregister(drvdata->csdev);
        return 0;
}

static int replicator_platform_probe(struct platform_device *pdev)
{
        struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        int ret;

        pm_runtime_get_noresume(&pdev->dev);
        pm_runtime_set_active(&pdev->dev);
        pm_runtime_enable(&pdev->dev);

        ret = replicator_probe(&pdev->dev, res);
        pm_runtime_put(&pdev->dev);
        if (ret)
                pm_runtime_disable(&pdev->dev);

        return ret;
}

static void replicator_platform_remove(struct platform_device *pdev)
{
        struct replicator_drvdata *drvdata = dev_get_drvdata(&pdev->dev);

        if (WARN_ON(!drvdata))
                return;

        replicator_remove(&pdev->dev);
        pm_runtime_disable(&pdev->dev);
}

#ifdef CONFIG_PM
static int replicator_runtime_suspend(struct device *dev)
{
        struct replicator_drvdata *drvdata = dev_get_drvdata(dev);

        clk_disable_unprepare(drvdata->atclk);
        clk_disable_unprepare(drvdata->pclk);

        return 0;
}

static int replicator_runtime_resume(struct device *dev)
{
        struct replicator_drvdata *drvdata = dev_get_drvdata(dev);
        int ret;

        ret = clk_prepare_enable(drvdata->pclk);
        if (ret)
                return ret;

        ret = clk_prepare_enable(drvdata->atclk);
        if (ret)
                clk_disable_unprepare(drvdata->pclk);

        return ret;
}
#endif

static const struct dev_pm_ops replicator_dev_pm_ops = {
        SET_RUNTIME_PM_OPS(replicator_runtime_suspend,
                           replicator_runtime_resume, NULL)
};

static const struct of_device_id replicator_match[] = {
        {.compatible = "arm,coresight-replicator"},
        {.compatible = "arm,coresight-static-replicator"},
        {}
};

MODULE_DEVICE_TABLE(of, replicator_match);

#ifdef CONFIG_ACPI
static const struct acpi_device_id replicator_acpi_ids[] = {
        {"ARMHC985", 0, 0, 0}, /* ARM CoreSight Static Replicator */
        {"ARMHC98D", 0, 0, 0}, /* ARM CoreSight Dynamic Replicator */
        {}
};

MODULE_DEVICE_TABLE(acpi, replicator_acpi_ids);
#endif

static struct platform_driver replicator_driver = {
        .probe          = replicator_platform_probe,
        .remove         = replicator_platform_remove,
        .driver         = {
                .name   = "coresight-replicator",
                /* THIS_MODULE is taken care of by platform_driver_register() */
                .of_match_table = of_match_ptr(replicator_match),
                .acpi_match_table = ACPI_PTR(replicator_acpi_ids),
                .pm     = &replicator_dev_pm_ops,
                .suppress_bind_attrs = true,
        },
};

static int dynamic_replicator_probe(struct amba_device *adev,
                                    const struct amba_id *id)
{
        int ret;

        ret = replicator_probe(&adev->dev, &adev->res);
        if (!ret)
                pm_runtime_put(&adev->dev);

        return ret;
}

static void dynamic_replicator_remove(struct amba_device *adev)
{
        replicator_remove(&adev->dev);
}

static const struct amba_id dynamic_replicator_ids[] = {
        CS_AMBA_ID(0x000bb909),
        CS_AMBA_ID(0x000bb9ec),         /* Coresight SoC-600 */
        {},
};

MODULE_DEVICE_TABLE(amba, dynamic_replicator_ids);

static struct amba_driver dynamic_replicator_driver = {
        .drv = {
                .name   = "coresight-dynamic-replicator",
                .pm     = &replicator_dev_pm_ops,
                .suppress_bind_attrs = true,
        },
        .probe          = dynamic_replicator_probe,
        .remove         = dynamic_replicator_remove,
        .id_table       = dynamic_replicator_ids,
};

static int __init replicator_init(void)
{
        return coresight_init_driver("replicator", &dynamic_replicator_driver, &replicator_driver,
                                     THIS_MODULE);
}

static void __exit replicator_exit(void)
{
        coresight_remove_driver(&dynamic_replicator_driver, &replicator_driver);
}

module_init(replicator_init);
module_exit(replicator_exit);

MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");
MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
MODULE_DESCRIPTION("Arm CoreSight Replicator Driver");
MODULE_LICENSE("GPL v2");