// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
 *
 * Description: CoreSight Funnel driver
 */

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

#include "coresight-priv.h"

#define FUNNEL_FUNCTL           0x000
#define FUNNEL_PRICTL           0x004

#define FUNNEL_HOLDTIME_MASK    0xf00
#define FUNNEL_HOLDTIME_SHFT    0x8
#define FUNNEL_HOLDTIME         (0x7 << FUNNEL_HOLDTIME_SHFT)
#define FUNNEL_ENSx_MASK        0xff

DEFINE_CORESIGHT_DEVLIST(funnel_devs, "funnel");

/**
 * struct funnel_drvdata - specifics associated to a funnel component
 * @base:       memory mapped base address for this component.
 * @atclk:      optional clock for the core parts of the funnel.
 * @pclk:       APB clock if present, otherwise NULL
 * @csdev:      component vitals needed by the framework.
 * @priority:   port selection order.
 * @spinlock:   serialize enable/disable operations.
 */
struct funnel_drvdata {
        void __iomem            *base;
        struct clk              *atclk;
        struct clk              *pclk;
        struct coresight_device *csdev;
        unsigned long           priority;
        raw_spinlock_t          spinlock;
};

static int dynamic_funnel_enable_hw(struct funnel_drvdata *drvdata, int port)
{
        u32 functl;
        int rc = 0;
        struct coresight_device *csdev = drvdata->csdev;

        CS_UNLOCK(drvdata->base);

        functl = readl_relaxed(drvdata->base + FUNNEL_FUNCTL);
        /* Claim the device only when we enable the first slave */
        if (!(functl & FUNNEL_ENSx_MASK)) {
                rc = coresight_claim_device_unlocked(csdev);
                if (rc)
                        goto done;
        }

        functl &= ~FUNNEL_HOLDTIME_MASK;
        functl |= FUNNEL_HOLDTIME;
        functl |= (1 << port);
        writel_relaxed(functl, drvdata->base + FUNNEL_FUNCTL);
        writel_relaxed(drvdata->priority, drvdata->base + FUNNEL_PRICTL);
done:
        CS_LOCK(drvdata->base);
        return rc;
}

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

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

        if (first_enable)
                dev_dbg(&csdev->dev, "FUNNEL inport %d enabled\n",
                        in->dest_port);
        return rc;
}

static void dynamic_funnel_disable_hw(struct funnel_drvdata *drvdata,
                                      int inport)
{
        u32 functl;
        struct coresight_device *csdev = drvdata->csdev;

        CS_UNLOCK(drvdata->base);

        functl = readl_relaxed(drvdata->base + FUNNEL_FUNCTL);
        functl &= ~(1 << inport);
        writel_relaxed(functl, drvdata->base + FUNNEL_FUNCTL);

        /* Disclaim the device if none of the slaves are now active */
        if (!(functl & FUNNEL_ENSx_MASK))
                coresight_disclaim_device_unlocked(csdev);

        CS_LOCK(drvdata->base);
}

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

        raw_spin_lock_irqsave(&drvdata->spinlock, flags);
        if (--in->dest_refcnt == 0) {
                if (drvdata->base)
                        dynamic_funnel_disable_hw(drvdata, in->dest_port);
                last_disable = true;
        }
        raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);

        if (last_disable)
                dev_dbg(&csdev->dev, "FUNNEL inport %d disabled\n",
                        in->dest_port);
}

static const struct coresight_ops_link funnel_link_ops = {
        .enable         = funnel_enable,
        .disable        = funnel_disable,
};

static const struct coresight_ops funnel_cs_ops = {
        .link_ops       = &funnel_link_ops,
};

static ssize_t priority_show(struct device *dev,
                             struct device_attribute *attr, char *buf)
{
        struct funnel_drvdata *drvdata = dev_get_drvdata(dev->parent);
        unsigned long val = drvdata->priority;

        return sprintf(buf, "%#lx\n", val);
}

static ssize_t priority_store(struct device *dev,
                              struct device_attribute *attr,
                              const char *buf, size_t size)
{
        int ret;
        unsigned long val;
        struct funnel_drvdata *drvdata = dev_get_drvdata(dev->parent);

        ret = kstrtoul(buf, 16, &val);
        if (ret)
                return ret;

        drvdata->priority = val;
        return size;
}
static DEVICE_ATTR_RW(priority);

static u32 get_funnel_ctrl_hw(struct funnel_drvdata *drvdata)
{
        u32 functl;

        CS_UNLOCK(drvdata->base);
        functl = readl_relaxed(drvdata->base + FUNNEL_FUNCTL);
        CS_LOCK(drvdata->base);

        return functl;
}

static ssize_t funnel_ctrl_show(struct device *dev,
                             struct device_attribute *attr, char *buf)
{
        u32 val;
        struct funnel_drvdata *drvdata = dev_get_drvdata(dev->parent);

        pm_runtime_get_sync(dev->parent);

        val = get_funnel_ctrl_hw(drvdata);

        pm_runtime_put(dev->parent);

        return sprintf(buf, "%#x\n", val);
}
static DEVICE_ATTR_RO(funnel_ctrl);

static struct attribute *coresight_funnel_attrs[] = {
        &dev_attr_funnel_ctrl.attr,
        &dev_attr_priority.attr,
        NULL,
};
ATTRIBUTE_GROUPS(coresight_funnel);

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

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

        desc.name = coresight_alloc_device_name(&funnel_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-funnel, 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 = coresight_funnel_groups;
                desc.access = CSDEV_ACCESS_IOMEM(base);
                coresight_clear_self_claim_tag(&desc.access);
        }

        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_MERG;
        desc.ops = &funnel_cs_ops;
        desc.pdata = pdata;
        desc.dev = dev;
        drvdata->csdev = coresight_register(&desc);
        if (IS_ERR(drvdata->csdev))
                return PTR_ERR(drvdata->csdev);

        return 0;
}

static int funnel_remove(struct device *dev)
{
        struct funnel_drvdata *drvdata = dev_get_drvdata(dev);

        coresight_unregister(drvdata->csdev);

        return 0;
}

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

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

        return 0;
}

static int funnel_runtime_resume(struct device *dev)
{
        struct funnel_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 funnel_dev_pm_ops = {
        SET_RUNTIME_PM_OPS(funnel_runtime_suspend, funnel_runtime_resume, NULL)
};

static int funnel_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 = funnel_probe(&pdev->dev, res);
        pm_runtime_put(&pdev->dev);
        if (ret)
                pm_runtime_disable(&pdev->dev);

        return ret;
}

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

        if (WARN_ON(!drvdata))
                return;

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

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

MODULE_DEVICE_TABLE(of, funnel_match);

#ifdef CONFIG_ACPI
static const struct acpi_device_id funnel_acpi_ids[] = {
        {"ARMHC9FE", 0, 0, 0}, /* ARM Coresight Static Funnel */
        {"ARMHC9FF", 0, 0, 0}, /* ARM CoreSight Dynamic Funnel */
        {},
};

MODULE_DEVICE_TABLE(acpi, funnel_acpi_ids);
#endif

static struct platform_driver funnel_driver = {
        .probe          = funnel_platform_probe,
        .remove         = funnel_platform_remove,
        .driver         = {
                .name   = "coresight-funnel",
                /* THIS_MODULE is taken care of by platform_driver_register() */
                .of_match_table = funnel_match,
                .acpi_match_table = ACPI_PTR(funnel_acpi_ids),
                .pm     = &funnel_dev_pm_ops,
                .suppress_bind_attrs = true,
        },
};

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

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

        return ret;
}

static void dynamic_funnel_remove(struct amba_device *adev)
{
        funnel_remove(&adev->dev);
}

static const struct amba_id dynamic_funnel_ids[] = {
        {
                .id     = 0x000bb908,
                .mask   = 0x000fffff,
        },
        {
                /* Coresight SoC-600 */
                .id     = 0x000bb9eb,
                .mask   = 0x000fffff,
        },
        { 0, 0, NULL },
};

MODULE_DEVICE_TABLE(amba, dynamic_funnel_ids);

static struct amba_driver dynamic_funnel_driver = {
        .drv = {
                .name   = "coresight-dynamic-funnel",
                .pm     = &funnel_dev_pm_ops,
                .suppress_bind_attrs = true,
        },
        .probe          = dynamic_funnel_probe,
        .remove         = dynamic_funnel_remove,
        .id_table       = dynamic_funnel_ids,
};

static int __init funnel_init(void)
{
        return coresight_init_driver("funnel", &dynamic_funnel_driver, &funnel_driver,
                                     THIS_MODULE);
}

static void __exit funnel_exit(void)
{
        coresight_remove_driver(&dynamic_funnel_driver, &funnel_driver);
}

module_init(funnel_init);
module_exit(funnel_exit);

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