/* Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/kernel.h>
#include <linux/module.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/clk.h>
#include <linux/coresight.h>
#include <linux/amba/bus.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)

/**
 * struct funnel_drvdata - specifics associated to a funnel component
 * @base:       memory mapped base address for this component.
 * @dev:        the device entity associated to this component.
 * @csdev:      component vitals needed by the framework.
 * @clk:        the clock this component is associated to.
 * @priority:   port selection order.
 */
struct funnel_drvdata {
        void __iomem            *base;
        struct device           *dev;
        struct coresight_device *csdev;
        struct clk              *clk;
        unsigned long           priority;
};

static void funnel_enable_hw(struct funnel_drvdata *drvdata, int port)
{
        u32 functl;

        CS_UNLOCK(drvdata->base);

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

        CS_LOCK(drvdata->base);
}

static int funnel_enable(struct coresight_device *csdev, int inport,
                         int outport)
{
        struct funnel_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
        int ret;

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

        funnel_enable_hw(drvdata, inport);

        dev_info(drvdata->dev, "FUNNEL inport %d enabled\n", inport);
        return 0;
}

static void funnel_disable_hw(struct funnel_drvdata *drvdata, int inport)
{
        u32 functl;

        CS_UNLOCK(drvdata->base);

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

        CS_LOCK(drvdata->base);
}

static void funnel_disable(struct coresight_device *csdev, int inport,
                           int outport)
{
        struct funnel_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);

        funnel_disable_hw(drvdata, inport);

        clk_disable_unprepare(drvdata->clk);

        dev_info(drvdata->dev, "FUNNEL inport %d disabled\n", inport);
}

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)
{
        int ret;
        u32 val;
        struct funnel_drvdata *drvdata = dev_get_drvdata(dev->parent);

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

        val = get_funnel_ctrl_hw(drvdata);
        clk_disable_unprepare(drvdata->clk);

        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 amba_device *adev, const struct amba_id *id)
{
        void __iomem *base;
        struct device *dev = &adev->dev;
        struct coresight_platform_data *pdata = NULL;
        struct funnel_drvdata *drvdata;
        struct resource *res = &adev->res;
        struct coresight_desc *desc;
        struct device_node *np = adev->dev.of_node;

        if (np) {
                pdata = of_get_coresight_platform_data(dev, np);
                if (IS_ERR(pdata))
                        return PTR_ERR(pdata);
                adev->dev.platform_data = pdata;
        }

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

        drvdata->dev = &adev->dev;
        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;

        drvdata->clk = adev->pclk;

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

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

        dev_info(dev, "FUNNEL initialized\n");
        return 0;
}

static int funnel_remove(struct amba_device *adev)
{
        struct funnel_drvdata *drvdata = amba_get_drvdata(adev);

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

static struct amba_id funnel_ids[] = {
        {
                .id     = 0x0003b908,
                .mask   = 0x0003ffff,
        },
        { 0, 0},
};

static struct amba_driver funnel_driver = {
        .drv = {
                .name   = "coresight-funnel",
                .owner  = THIS_MODULE,
        },
        .probe          = funnel_probe,
        .remove         = funnel_remove,
        .id_table       = funnel_ids,
};

module_amba_driver(funnel_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("CoreSight Funnel driver");