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

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

#include "coresight-priv.h"

#define TPIU_SUPP_PORTSZ        0x000
#define TPIU_CURR_PORTSZ        0x004
#define TPIU_SUPP_TRIGMODES     0x100
#define TPIU_TRIG_CNTRVAL       0x104
#define TPIU_TRIG_MULT          0x108
#define TPIU_SUPP_TESTPATM      0x200
#define TPIU_CURR_TESTPATM      0x204
#define TPIU_TEST_PATREPCNTR    0x208
#define TPIU_FFSR               0x300
#define TPIU_FFCR               0x304
#define TPIU_FSYNC_CNTR         0x308
#define TPIU_EXTCTL_INPORT      0x400
#define TPIU_EXTCTL_OUTPORT     0x404
#define TPIU_ITTRFLINACK        0xee4
#define TPIU_ITTRFLIN           0xee8
#define TPIU_ITATBDATA0         0xeec
#define TPIU_ITATBCTR2          0xef0
#define TPIU_ITATBCTR1          0xef4
#define TPIU_ITATBCTR0          0xef8

/** register definition **/
/* FFSR - 0x300 */
#define FFSR_FT_STOPPED_BIT     1
/* FFCR - 0x304 */
#define FFCR_FON_MAN_BIT        6
#define FFCR_FON_MAN            BIT(6)
#define FFCR_STOP_FI            BIT(12)

DEFINE_CORESIGHT_DEVLIST(tpiu_devs, "tpiu");

/*
 * @base:       memory mapped base address for this component.
 * @atclk:      optional clock for the core parts of the TPIU.
 * @pclk:       APB clock if present, otherwise NULL
 * @csdev:      component vitals needed by the framework.
 */
struct tpiu_drvdata {
        void __iomem            *base;
        struct clk              *atclk;
        struct clk              *pclk;
        struct coresight_device *csdev;
        spinlock_t              spinlock;
};

static void tpiu_enable_hw(struct csdev_access *csa)
{
        CS_UNLOCK(csa->base);

        /* TODO: fill this up */

        CS_LOCK(csa->base);
}

static int tpiu_enable(struct coresight_device *csdev, enum cs_mode mode,
                       struct coresight_path *path)
{
        struct tpiu_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);

        guard(spinlock)(&drvdata->spinlock);
        tpiu_enable_hw(&csdev->access);
        csdev->refcnt++;
        dev_dbg(&csdev->dev, "TPIU enabled\n");
        return 0;
}

static void tpiu_disable_hw(struct csdev_access *csa)
{
        CS_UNLOCK(csa->base);

        /* Clear formatter and stop on flush */
        csdev_access_relaxed_write32(csa, FFCR_STOP_FI, TPIU_FFCR);
        /* Generate manual flush */
        csdev_access_relaxed_write32(csa, FFCR_STOP_FI | FFCR_FON_MAN, TPIU_FFCR);
        /* Wait for flush to complete */
        coresight_timeout(csa, TPIU_FFCR, FFCR_FON_MAN_BIT, 0);
        /* Wait for formatter to stop */
        coresight_timeout(csa, TPIU_FFSR, FFSR_FT_STOPPED_BIT, 1);

        CS_LOCK(csa->base);
}

static int tpiu_disable(struct coresight_device *csdev)
{
        struct tpiu_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);

        guard(spinlock)(&drvdata->spinlock);
        csdev->refcnt--;
        if (csdev->refcnt)
                return -EBUSY;

        tpiu_disable_hw(&csdev->access);

        dev_dbg(&csdev->dev, "TPIU disabled\n");
        return 0;
}

static const struct coresight_ops_sink tpiu_sink_ops = {
        .enable         = tpiu_enable,
        .disable        = tpiu_disable,
};

static const struct coresight_ops tpiu_cs_ops = {
        .sink_ops       = &tpiu_sink_ops,
};

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

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

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

        spin_lock_init(&drvdata->spinlock);

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

        dev_set_drvdata(dev, drvdata);

        /* Validity for the resource is already checked by the AMBA core */
        base = devm_ioremap_resource(dev, res);
        if (IS_ERR(base))
                return PTR_ERR(base);

        drvdata->base = base;
        desc.access = CSDEV_ACCESS_IOMEM(base);

        /* Disable tpiu to support older devices */
        tpiu_disable_hw(&desc.access);

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

        desc.type = CORESIGHT_DEV_TYPE_SINK;
        desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_PORT;
        desc.ops = &tpiu_cs_ops;
        desc.pdata = pdata;
        desc.dev = dev;
        drvdata->csdev = coresight_register(&desc);

        if (!IS_ERR(drvdata->csdev))
                return 0;

        return PTR_ERR(drvdata->csdev);
}

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

        ret = __tpiu_probe(&adev->dev, &adev->res);
        if (!ret)
                pm_runtime_put(&adev->dev);
        return ret;
}

static void __tpiu_remove(struct device *dev)
{
        struct tpiu_drvdata *drvdata = dev_get_drvdata(dev);

        coresight_unregister(drvdata->csdev);
}

static void tpiu_remove(struct amba_device *adev)
{
        __tpiu_remove(&adev->dev);
}

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

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

        return 0;
}

static int tpiu_runtime_resume(struct device *dev)
{
        struct tpiu_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 tpiu_dev_pm_ops = {
        SET_RUNTIME_PM_OPS(tpiu_runtime_suspend, tpiu_runtime_resume, NULL)
};

static const struct amba_id tpiu_ids[] = {
        {
                .id     = 0x000bb912,
                .mask   = 0x000fffff,
        },
        {
                .id     = 0x0004b912,
                .mask   = 0x0007ffff,
        },
        {
                /* Coresight SoC-600 */
                .id     = 0x000bb9e7,
                .mask   = 0x000fffff,
        },
        { 0, 0, NULL },
};

MODULE_DEVICE_TABLE(amba, tpiu_ids);

static struct amba_driver tpiu_driver = {
        .drv = {
                .name   = "coresight-tpiu",
                .pm     = &tpiu_dev_pm_ops,
                .suppress_bind_attrs = true,
        },
        .probe          = tpiu_probe,
        .remove         = tpiu_remove,
        .id_table       = tpiu_ids,
};

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

        return ret;
}

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

        if (WARN_ON(!drvdata))
                return;

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

#ifdef CONFIG_ACPI
static const struct acpi_device_id tpiu_acpi_ids[] = {
        {"ARMHC979", 0, 0, 0}, /* ARM CoreSight TPIU */
        {}
};
MODULE_DEVICE_TABLE(acpi, tpiu_acpi_ids);
#endif

static struct platform_driver tpiu_platform_driver = {
        .probe  = tpiu_platform_probe,
        .remove = tpiu_platform_remove,
        .driver = {
                .name                   = "coresight-tpiu-platform",
                .acpi_match_table       = ACPI_PTR(tpiu_acpi_ids),
                .suppress_bind_attrs    = true,
                .pm                     = &tpiu_dev_pm_ops,
        },
};

static int __init tpiu_init(void)
{
        return coresight_init_driver("tpiu", &tpiu_driver, &tpiu_platform_driver, THIS_MODULE);
}

static void __exit tpiu_exit(void)
{
        coresight_remove_driver(&tpiu_driver, &tpiu_platform_driver);
}
module_init(tpiu_init);
module_exit(tpiu_exit);

MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");
MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
MODULE_DESCRIPTION("Arm CoreSight TPIU (Trace Port Interface Unit) driver");
MODULE_LICENSE("GPL v2");