/*
 * Copyright (c) 2014, NVIDIA CORPORATION. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */
#include <core/tegra.h>
#ifdef CONFIG_NOUVEAU_PLATFORM_DRIVER
#include "priv.h"

#if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
#include <asm/dma-iommu.h>
#endif

static int
nvkm_device_tegra_power_up(struct nvkm_device_tegra *tdev)
{
        int ret;

        if (tdev->vdd) {
                ret = regulator_enable(tdev->vdd);
                if (ret)
                        goto err_power;
        }

        ret = clk_prepare_enable(tdev->clk);
        if (ret)
                goto err_clk;
        if (tdev->clk_ref) {
                ret = clk_prepare_enable(tdev->clk_ref);
                if (ret)
                        goto err_clk_ref;
        }
        ret = clk_prepare_enable(tdev->clk_pwr);
        if (ret)
                goto err_clk_pwr;
        clk_set_rate(tdev->clk_pwr, 204000000);
        udelay(10);

        if (!tdev->pdev->dev.pm_domain) {
                reset_control_assert(tdev->rst);
                udelay(10);

                ret = tegra_powergate_remove_clamping(TEGRA_POWERGATE_3D);
                if (ret)
                        goto err_clamp;
                udelay(10);

                reset_control_deassert(tdev->rst);
                udelay(10);
        }

        return 0;

err_clamp:
        clk_disable_unprepare(tdev->clk_pwr);
err_clk_pwr:
        if (tdev->clk_ref)
                clk_disable_unprepare(tdev->clk_ref);
err_clk_ref:
        clk_disable_unprepare(tdev->clk);
err_clk:
        if (tdev->vdd)
                regulator_disable(tdev->vdd);
err_power:
        return ret;
}

static int
nvkm_device_tegra_power_down(struct nvkm_device_tegra *tdev)
{
        int ret;

        clk_disable_unprepare(tdev->clk_pwr);
        if (tdev->clk_ref)
                clk_disable_unprepare(tdev->clk_ref);
        clk_disable_unprepare(tdev->clk);
        udelay(10);

        if (tdev->vdd) {
                ret = regulator_disable(tdev->vdd);
                if (ret)
                        return ret;
        }

        return 0;
}

static void
nvkm_device_tegra_probe_iommu(struct nvkm_device_tegra *tdev)
{
#if IS_ENABLED(CONFIG_IOMMU_API)
        struct device *dev = &tdev->pdev->dev;
        unsigned long pgsize_bitmap;
        int ret;

#if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
        if (dev->archdata.mapping) {
                struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);

                arm_iommu_detach_device(dev);
                arm_iommu_release_mapping(mapping);
        }
#endif

        if (!tdev->func->iommu_bit)
                return;

        mutex_init(&tdev->iommu.mutex);

        if (iommu_present(&platform_bus_type)) {
                tdev->iommu.domain = iommu_domain_alloc(&platform_bus_type);
                if (!tdev->iommu.domain)
                        goto error;

                /*
                 * A IOMMU is only usable if it supports page sizes smaller
                 * or equal to the system's PAGE_SIZE, with a preference if
                 * both are equal.
                 */
                pgsize_bitmap = tdev->iommu.domain->ops->pgsize_bitmap;
                if (pgsize_bitmap & PAGE_SIZE) {
                        tdev->iommu.pgshift = PAGE_SHIFT;
                } else {
                        tdev->iommu.pgshift = fls(pgsize_bitmap & ~PAGE_MASK);
                        if (tdev->iommu.pgshift == 0) {
                                dev_warn(dev, "unsupported IOMMU page size\n");
                                goto free_domain;
                        }
                        tdev->iommu.pgshift -= 1;
                }

                ret = iommu_attach_device(tdev->iommu.domain, dev);
                if (ret)
                        goto free_domain;

                ret = nvkm_mm_init(&tdev->iommu.mm, 0, 0,
                                   (1ULL << tdev->func->iommu_bit) >>
                                   tdev->iommu.pgshift, 1);
                if (ret)
                        goto detach_device;
        }

        return;

detach_device:
        iommu_detach_device(tdev->iommu.domain, dev);

free_domain:
        iommu_domain_free(tdev->iommu.domain);

error:
        tdev->iommu.domain = NULL;
        tdev->iommu.pgshift = 0;
        dev_err(dev, "cannot initialize IOMMU MM\n");
#endif
}

static void
nvkm_device_tegra_remove_iommu(struct nvkm_device_tegra *tdev)
{
#if IS_ENABLED(CONFIG_IOMMU_API)
        if (tdev->iommu.domain) {
                nvkm_mm_fini(&tdev->iommu.mm);
                iommu_detach_device(tdev->iommu.domain, tdev->device.dev);
                iommu_domain_free(tdev->iommu.domain);
        }
#endif
}

static struct nvkm_device_tegra *
nvkm_device_tegra(struct nvkm_device *device)
{
        return container_of(device, struct nvkm_device_tegra, device);
}

static struct resource *
nvkm_device_tegra_resource(struct nvkm_device *device, unsigned bar)
{
        struct nvkm_device_tegra *tdev = nvkm_device_tegra(device);
        return platform_get_resource(tdev->pdev, IORESOURCE_MEM, bar);
}

static resource_size_t
nvkm_device_tegra_resource_addr(struct nvkm_device *device, unsigned bar)
{
        struct resource *res = nvkm_device_tegra_resource(device, bar);
        return res ? res->start : 0;
}

static resource_size_t
nvkm_device_tegra_resource_size(struct nvkm_device *device, unsigned bar)
{
        struct resource *res = nvkm_device_tegra_resource(device, bar);
        return res ? resource_size(res) : 0;
}

static irqreturn_t
nvkm_device_tegra_intr(int irq, void *arg)
{
        struct nvkm_device_tegra *tdev = arg;
        struct nvkm_device *device = &tdev->device;
        bool handled = false;
        nvkm_mc_intr_unarm(device);
        nvkm_mc_intr(device, &handled);
        nvkm_mc_intr_rearm(device);
        return handled ? IRQ_HANDLED : IRQ_NONE;
}

static void
nvkm_device_tegra_fini(struct nvkm_device *device, bool suspend)
{
        struct nvkm_device_tegra *tdev = nvkm_device_tegra(device);
        if (tdev->irq) {
                free_irq(tdev->irq, tdev);
                tdev->irq = 0;
        }
}

static int
nvkm_device_tegra_init(struct nvkm_device *device)
{
        struct nvkm_device_tegra *tdev = nvkm_device_tegra(device);
        int irq, ret;

        irq = platform_get_irq_byname(tdev->pdev, "stall");
        if (irq < 0)
                return irq;

        ret = request_irq(irq, nvkm_device_tegra_intr,
                          IRQF_SHARED, "nvkm", tdev);
        if (ret)
                return ret;

        tdev->irq = irq;
        return 0;
}

static void *
nvkm_device_tegra_dtor(struct nvkm_device *device)
{
        struct nvkm_device_tegra *tdev = nvkm_device_tegra(device);
        nvkm_device_tegra_power_down(tdev);
        nvkm_device_tegra_remove_iommu(tdev);
        return tdev;
}

static const struct nvkm_device_func
nvkm_device_tegra_func = {
        .tegra = nvkm_device_tegra,
        .dtor = nvkm_device_tegra_dtor,
        .init = nvkm_device_tegra_init,
        .fini = nvkm_device_tegra_fini,
        .resource_addr = nvkm_device_tegra_resource_addr,
        .resource_size = nvkm_device_tegra_resource_size,
        .cpu_coherent = false,
};

int
nvkm_device_tegra_new(const struct nvkm_device_tegra_func *func,
                      struct platform_device *pdev,
                      const char *cfg, const char *dbg,
                      bool detect, bool mmio, u64 subdev_mask,
                      struct nvkm_device **pdevice)
{
        struct nvkm_device_tegra *tdev;
        unsigned long rate;
        int ret;

        if (!(tdev = kzalloc(sizeof(*tdev), GFP_KERNEL)))
                return -ENOMEM;

        tdev->func = func;
        tdev->pdev = pdev;

        if (func->require_vdd) {
                tdev->vdd = devm_regulator_get(&pdev->dev, "vdd");
                if (IS_ERR(tdev->vdd)) {
                        ret = PTR_ERR(tdev->vdd);
                        goto free;
                }
        }

        tdev->rst = devm_reset_control_get(&pdev->dev, "gpu");
        if (IS_ERR(tdev->rst)) {
                ret = PTR_ERR(tdev->rst);
                goto free;
        }

        tdev->clk = devm_clk_get(&pdev->dev, "gpu");
        if (IS_ERR(tdev->clk)) {
                ret = PTR_ERR(tdev->clk);
                goto free;
        }

        rate = clk_get_rate(tdev->clk);
        if (rate == 0) {
                ret = clk_set_rate(tdev->clk, ULONG_MAX);
                if (ret < 0)
                        goto free;

                rate = clk_get_rate(tdev->clk);

                dev_dbg(&pdev->dev, "GPU clock set to %lu\n", rate);
        }

        if (func->require_ref_clk)
                tdev->clk_ref = devm_clk_get(&pdev->dev, "ref");
        if (IS_ERR(tdev->clk_ref)) {
                ret = PTR_ERR(tdev->clk_ref);
                goto free;
        }

        tdev->clk_pwr = devm_clk_get(&pdev->dev, "pwr");
        if (IS_ERR(tdev->clk_pwr)) {
                ret = PTR_ERR(tdev->clk_pwr);
                goto free;
        }

        /**
         * The IOMMU bit defines the upper limit of the GPU-addressable space.
         */
        ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(tdev->func->iommu_bit));
        if (ret)
                goto free;

        nvkm_device_tegra_probe_iommu(tdev);

        ret = nvkm_device_tegra_power_up(tdev);
        if (ret)
                goto remove;

        tdev->gpu_speedo = tegra_sku_info.gpu_speedo_value;
        tdev->gpu_speedo_id = tegra_sku_info.gpu_speedo_id;
        ret = nvkm_device_ctor(&nvkm_device_tegra_func, NULL, &pdev->dev,
                               NVKM_DEVICE_TEGRA, pdev->id, NULL,
                               cfg, dbg, detect, mmio, subdev_mask,
                               &tdev->device);
        if (ret)
                goto powerdown;

        *pdevice = &tdev->device;

        return 0;

powerdown:
        nvkm_device_tegra_power_down(tdev);
remove:
        nvkm_device_tegra_remove_iommu(tdev);
free:
        kfree(tdev);
        return ret;
}
#else
int
nvkm_device_tegra_new(const struct nvkm_device_tegra_func *func,
                      struct platform_device *pdev,
                      const char *cfg, const char *dbg,
                      bool detect, bool mmio, u64 subdev_mask,
                      struct nvkm_device **pdevice)
{
        return -ENOSYS;
}
#endif