// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2018, NVIDIA CORPORATION.
 */

#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/platform_device.h>

#include <soc/tegra/bpmp.h>

#include "bpmp-private.h"

#define TRIGGER_OFFSET          0x000
#define RESULT_OFFSET(id)       (0xc00 + id * 4)
#define TRIGGER_ID_SHIFT        16
#define TRIGGER_CMD_GET         4

#define STA_OFFSET              0
#define SET_OFFSET              4
#define CLR_OFFSET              8

#define CH_MASK(ch)     (0x3 << ((ch) * 2))
#define SL_SIGL(ch)     (0x0 << ((ch) * 2))
#define SL_QUED(ch)     (0x1 << ((ch) * 2))
#define MA_FREE(ch)     (0x2 << ((ch) * 2))
#define MA_ACKD(ch)     (0x3 << ((ch) * 2))

struct tegra210_bpmp {
        void __iomem *atomics;
        void __iomem *arb_sema;
        struct irq_data *tx_irq_data;
};

static u32 bpmp_channel_status(struct tegra_bpmp *bpmp, unsigned int index)
{
        struct tegra210_bpmp *priv = bpmp->priv;

        return __raw_readl(priv->arb_sema + STA_OFFSET) & CH_MASK(index);
}

static bool tegra210_bpmp_is_response_ready(struct tegra_bpmp_channel *channel)
{
        unsigned int index = channel->index;

        return bpmp_channel_status(channel->bpmp, index) == MA_ACKD(index);
}

static bool tegra210_bpmp_is_request_ready(struct tegra_bpmp_channel *channel)
{
        unsigned int index = channel->index;

        return bpmp_channel_status(channel->bpmp, index) == SL_SIGL(index);
}

static bool
tegra210_bpmp_is_request_channel_free(struct tegra_bpmp_channel *channel)
{
        unsigned int index = channel->index;

        return bpmp_channel_status(channel->bpmp, index) == MA_FREE(index);
}

static bool
tegra210_bpmp_is_response_channel_free(struct tegra_bpmp_channel *channel)
{
        unsigned int index = channel->index;

        return bpmp_channel_status(channel->bpmp, index) == SL_QUED(index);
}

static int tegra210_bpmp_post_request(struct tegra_bpmp_channel *channel)
{
        struct tegra210_bpmp *priv = channel->bpmp->priv;

        __raw_writel(CH_MASK(channel->index), priv->arb_sema + CLR_OFFSET);

        return 0;
}

static int tegra210_bpmp_post_response(struct tegra_bpmp_channel *channel)
{
        struct tegra210_bpmp *priv = channel->bpmp->priv;

        __raw_writel(MA_ACKD(channel->index), priv->arb_sema + SET_OFFSET);

        return 0;
}

static int tegra210_bpmp_ack_response(struct tegra_bpmp_channel *channel)
{
        struct tegra210_bpmp *priv = channel->bpmp->priv;

        __raw_writel(MA_ACKD(channel->index) ^ MA_FREE(channel->index),
                     priv->arb_sema + CLR_OFFSET);

        return 0;
}

static int tegra210_bpmp_ack_request(struct tegra_bpmp_channel *channel)
{
        struct tegra210_bpmp *priv = channel->bpmp->priv;

        __raw_writel(SL_QUED(channel->index), priv->arb_sema + SET_OFFSET);

        return 0;
}

static int tegra210_bpmp_ring_doorbell(struct tegra_bpmp *bpmp)
{
        struct tegra210_bpmp *priv = bpmp->priv;
        struct irq_data *irq_data = priv->tx_irq_data;

        /*
         * Tegra Legacy Interrupt Controller (LIC) is used to notify BPMP of
         * available messages
         */
        if (irq_data->chip->irq_retrigger)
                return irq_data->chip->irq_retrigger(irq_data);

        return -EINVAL;
}

static irqreturn_t rx_irq(int irq, void *data)
{
        struct tegra_bpmp *bpmp = data;

        tegra_bpmp_handle_rx(bpmp);

        return IRQ_HANDLED;
}

static int tegra210_bpmp_channel_init(struct tegra_bpmp_channel *channel,
                                      struct tegra_bpmp *bpmp,
                                      unsigned int index)
{
        struct tegra210_bpmp *priv = bpmp->priv;
        void __iomem *p;
        u32 address;

        /* Retrieve channel base address from BPMP */
        writel(index << TRIGGER_ID_SHIFT | TRIGGER_CMD_GET,
               priv->atomics + TRIGGER_OFFSET);
        address = readl(priv->atomics + RESULT_OFFSET(index));

        p = devm_ioremap(bpmp->dev, address, 0x80);
        if (!p)
                return -ENOMEM;

        iosys_map_set_vaddr_iomem(&channel->ib, p);
        iosys_map_set_vaddr_iomem(&channel->ob, p);

        channel->index = index;
        init_completion(&channel->completion);
        channel->bpmp = bpmp;

        return 0;
}

static int tegra210_bpmp_init(struct tegra_bpmp *bpmp)
{
        struct platform_device *pdev = to_platform_device(bpmp->dev);
        struct tegra210_bpmp *priv;
        unsigned int i;
        int err;

        priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
        if (!priv)
                return -ENOMEM;

        bpmp->priv = priv;

        priv->atomics = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(priv->atomics))
                return PTR_ERR(priv->atomics);

        priv->arb_sema = devm_platform_ioremap_resource(pdev, 1);
        if (IS_ERR(priv->arb_sema))
                return PTR_ERR(priv->arb_sema);

        err = tegra210_bpmp_channel_init(bpmp->tx_channel, bpmp,
                                         bpmp->soc->channels.cpu_tx.offset);
        if (err < 0)
                return err;

        err = tegra210_bpmp_channel_init(bpmp->rx_channel, bpmp,
                                         bpmp->soc->channels.cpu_rx.offset);
        if (err < 0)
                return err;

        for (i = 0; i < bpmp->threaded.count; i++) {
                unsigned int index = bpmp->soc->channels.thread.offset + i;

                err = tegra210_bpmp_channel_init(&bpmp->threaded_channels[i],
                                                 bpmp, index);
                if (err < 0)
                        return err;
        }

        err = platform_get_irq_byname(pdev, "tx");
        if (err < 0)
                return err;

        priv->tx_irq_data = irq_get_irq_data(err);
        if (!priv->tx_irq_data) {
                dev_err(&pdev->dev, "failed to get IRQ data for TX IRQ\n");
                return -ENOENT;
        }

        err = platform_get_irq_byname(pdev, "rx");
        if (err < 0)
                return err;

        err = devm_request_irq(&pdev->dev, err, rx_irq,
                               IRQF_NO_SUSPEND, dev_name(&pdev->dev), bpmp);
        if (err < 0) {
                dev_err(&pdev->dev, "failed to request IRQ: %d\n", err);
                return err;
        }

        return 0;
}

const struct tegra_bpmp_ops tegra210_bpmp_ops = {
        .init = tegra210_bpmp_init,
        .is_response_ready = tegra210_bpmp_is_response_ready,
        .is_request_ready = tegra210_bpmp_is_request_ready,
        .ack_response = tegra210_bpmp_ack_response,
        .ack_request = tegra210_bpmp_ack_request,
        .is_response_channel_free = tegra210_bpmp_is_response_channel_free,
        .is_request_channel_free = tegra210_bpmp_is_request_channel_free,
        .post_response = tegra210_bpmp_post_response,
        .post_request = tegra210_bpmp_post_request,
        .ring_doorbell = tegra210_bpmp_ring_doorbell,
};