// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2014 NVIDIA CORPORATION.  All rights reserved.
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/export.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/sort.h>

#include <soc/tegra/fuse.h>

#include "mc.h"

static const struct of_device_id tegra_mc_of_match[] = {
#ifdef CONFIG_ARCH_TEGRA_2x_SOC
        { .compatible = "nvidia,tegra20-mc-gart", .data = &tegra20_mc_soc },
#endif
#ifdef CONFIG_ARCH_TEGRA_3x_SOC
        { .compatible = "nvidia,tegra30-mc", .data = &tegra30_mc_soc },
#endif
#ifdef CONFIG_ARCH_TEGRA_114_SOC
        { .compatible = "nvidia,tegra114-mc", .data = &tegra114_mc_soc },
#endif
#ifdef CONFIG_ARCH_TEGRA_124_SOC
        { .compatible = "nvidia,tegra124-mc", .data = &tegra124_mc_soc },
#endif
#ifdef CONFIG_ARCH_TEGRA_132_SOC
        { .compatible = "nvidia,tegra132-mc", .data = &tegra132_mc_soc },
#endif
#ifdef CONFIG_ARCH_TEGRA_210_SOC
        { .compatible = "nvidia,tegra210-mc", .data = &tegra210_mc_soc },
#endif
#ifdef CONFIG_ARCH_TEGRA_186_SOC
        { .compatible = "nvidia,tegra186-mc", .data = &tegra186_mc_soc },
#endif
#ifdef CONFIG_ARCH_TEGRA_194_SOC
        { .compatible = "nvidia,tegra194-mc", .data = &tegra194_mc_soc },
#endif
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, tegra_mc_of_match);

static void tegra_mc_devm_action_put_device(void *data)
{
        struct tegra_mc *mc = data;

        put_device(mc->dev);
}

/**
 * devm_tegra_memory_controller_get() - get Tegra Memory Controller handle
 * @dev: device pointer for the consumer device
 *
 * This function will search for the Memory Controller node in a device-tree
 * and retrieve the Memory Controller handle.
 *
 * Return: ERR_PTR() on error or a valid pointer to a struct tegra_mc.
 */
struct tegra_mc *devm_tegra_memory_controller_get(struct device *dev)
{
        struct platform_device *pdev;
        struct device_node *np;
        struct tegra_mc *mc;
        int err;

        np = of_parse_phandle(dev->of_node, "nvidia,memory-controller", 0);
        if (!np)
                return ERR_PTR(-ENOENT);

        pdev = of_find_device_by_node(np);
        of_node_put(np);
        if (!pdev)
                return ERR_PTR(-ENODEV);

        mc = platform_get_drvdata(pdev);
        if (!mc) {
                put_device(&pdev->dev);
                return ERR_PTR(-EPROBE_DEFER);
        }

        err = devm_add_action(dev, tegra_mc_devm_action_put_device, mc);
        if (err) {
                put_device(mc->dev);
                return ERR_PTR(err);
        }

        return mc;
}
EXPORT_SYMBOL_GPL(devm_tegra_memory_controller_get);

int tegra_mc_probe_device(struct tegra_mc *mc, struct device *dev)
{
        if (mc->soc->ops && mc->soc->ops->probe_device)
                return mc->soc->ops->probe_device(mc, dev);

        return 0;
}
EXPORT_SYMBOL_GPL(tegra_mc_probe_device);

static int tegra_mc_block_dma_common(struct tegra_mc *mc,
                                     const struct tegra_mc_reset *rst)
{
        unsigned long flags;
        u32 value;

        spin_lock_irqsave(&mc->lock, flags);

        value = mc_readl(mc, rst->control) | BIT(rst->bit);
        mc_writel(mc, value, rst->control);

        spin_unlock_irqrestore(&mc->lock, flags);

        return 0;
}

static bool tegra_mc_dma_idling_common(struct tegra_mc *mc,
                                       const struct tegra_mc_reset *rst)
{
        return (mc_readl(mc, rst->status) & BIT(rst->bit)) != 0;
}

static int tegra_mc_unblock_dma_common(struct tegra_mc *mc,
                                       const struct tegra_mc_reset *rst)
{
        unsigned long flags;
        u32 value;

        spin_lock_irqsave(&mc->lock, flags);

        value = mc_readl(mc, rst->control) & ~BIT(rst->bit);
        mc_writel(mc, value, rst->control);

        spin_unlock_irqrestore(&mc->lock, flags);

        return 0;
}

static int tegra_mc_reset_status_common(struct tegra_mc *mc,
                                        const struct tegra_mc_reset *rst)
{
        return (mc_readl(mc, rst->control) & BIT(rst->bit)) != 0;
}

const struct tegra_mc_reset_ops tegra_mc_reset_ops_common = {
        .block_dma = tegra_mc_block_dma_common,
        .dma_idling = tegra_mc_dma_idling_common,
        .unblock_dma = tegra_mc_unblock_dma_common,
        .reset_status = tegra_mc_reset_status_common,
};

static inline struct tegra_mc *reset_to_mc(struct reset_controller_dev *rcdev)
{
        return container_of(rcdev, struct tegra_mc, reset);
}

static const struct tegra_mc_reset *tegra_mc_reset_find(struct tegra_mc *mc,
                                                        unsigned long id)
{
        unsigned int i;

        for (i = 0; i < mc->soc->num_resets; i++)
                if (mc->soc->resets[i].id == id)
                        return &mc->soc->resets[i];

        return NULL;
}

static int tegra_mc_hotreset_assert(struct reset_controller_dev *rcdev,
                                    unsigned long id)
{
        struct tegra_mc *mc = reset_to_mc(rcdev);
        const struct tegra_mc_reset_ops *rst_ops;
        const struct tegra_mc_reset *rst;
        int retries = 500;
        int err;

        rst = tegra_mc_reset_find(mc, id);
        if (!rst)
                return -ENODEV;

        rst_ops = mc->soc->reset_ops;
        if (!rst_ops)
                return -ENODEV;

        /* DMA flushing will fail if reset is already asserted */
        if (rst_ops->reset_status) {
                /* check whether reset is asserted */
                if (rst_ops->reset_status(mc, rst))
                        return 0;
        }

        if (rst_ops->block_dma) {
                /* block clients DMA requests */
                err = rst_ops->block_dma(mc, rst);
                if (err) {
                        dev_err(mc->dev, "failed to block %s DMA: %d\n",
                                rst->name, err);
                        return err;
                }
        }

        if (rst_ops->dma_idling) {
                /* wait for completion of the outstanding DMA requests */
                while (!rst_ops->dma_idling(mc, rst)) {
                        if (!retries--) {
                                dev_err(mc->dev, "failed to flush %s DMA\n",
                                        rst->name);
                                return -EBUSY;
                        }

                        usleep_range(10, 100);
                }
        }

        if (rst_ops->hotreset_assert) {
                /* clear clients DMA requests sitting before arbitration */
                err = rst_ops->hotreset_assert(mc, rst);
                if (err) {
                        dev_err(mc->dev, "failed to hot reset %s: %d\n",
                                rst->name, err);
                        return err;
                }
        }

        return 0;
}

static int tegra_mc_hotreset_deassert(struct reset_controller_dev *rcdev,
                                      unsigned long id)
{
        struct tegra_mc *mc = reset_to_mc(rcdev);
        const struct tegra_mc_reset_ops *rst_ops;
        const struct tegra_mc_reset *rst;
        int err;

        rst = tegra_mc_reset_find(mc, id);
        if (!rst)
                return -ENODEV;

        rst_ops = mc->soc->reset_ops;
        if (!rst_ops)
                return -ENODEV;

        if (rst_ops->hotreset_deassert) {
                /* take out client from hot reset */
                err = rst_ops->hotreset_deassert(mc, rst);
                if (err) {
                        dev_err(mc->dev, "failed to deassert hot reset %s: %d\n",
                                rst->name, err);
                        return err;
                }
        }

        if (rst_ops->unblock_dma) {
                /* allow new DMA requests to proceed to arbitration */
                err = rst_ops->unblock_dma(mc, rst);
                if (err) {
                        dev_err(mc->dev, "failed to unblock %s DMA : %d\n",
                                rst->name, err);
                        return err;
                }
        }

        return 0;
}

static int tegra_mc_hotreset_status(struct reset_controller_dev *rcdev,
                                    unsigned long id)
{
        struct tegra_mc *mc = reset_to_mc(rcdev);
        const struct tegra_mc_reset_ops *rst_ops;
        const struct tegra_mc_reset *rst;

        rst = tegra_mc_reset_find(mc, id);
        if (!rst)
                return -ENODEV;

        rst_ops = mc->soc->reset_ops;
        if (!rst_ops)
                return -ENODEV;

        return rst_ops->reset_status(mc, rst);
}

static const struct reset_control_ops tegra_mc_reset_ops = {
        .assert = tegra_mc_hotreset_assert,
        .deassert = tegra_mc_hotreset_deassert,
        .status = tegra_mc_hotreset_status,
};

static int tegra_mc_reset_setup(struct tegra_mc *mc)
{
        int err;

        mc->reset.ops = &tegra_mc_reset_ops;
        mc->reset.owner = THIS_MODULE;
        mc->reset.of_node = mc->dev->of_node;
        mc->reset.of_reset_n_cells = 1;
        mc->reset.nr_resets = mc->soc->num_resets;

        err = reset_controller_register(&mc->reset);
        if (err < 0)
                return err;

        return 0;
}

int tegra_mc_write_emem_configuration(struct tegra_mc *mc, unsigned long rate)
{
        unsigned int i;
        struct tegra_mc_timing *timing = NULL;

        for (i = 0; i < mc->num_timings; i++) {
                if (mc->timings[i].rate == rate) {
                        timing = &mc->timings[i];
                        break;
                }
        }

        if (!timing) {
                dev_err(mc->dev, "no memory timing registered for rate %lu\n",
                        rate);
                return -EINVAL;
        }

        for (i = 0; i < mc->soc->num_emem_regs; ++i)
                mc_writel(mc, timing->emem_data[i], mc->soc->emem_regs[i]);

        return 0;
}
EXPORT_SYMBOL_GPL(tegra_mc_write_emem_configuration);

unsigned int tegra_mc_get_emem_device_count(struct tegra_mc *mc)
{
        u8 dram_count;

        dram_count = mc_readl(mc, MC_EMEM_ADR_CFG);
        dram_count &= MC_EMEM_ADR_CFG_EMEM_NUMDEV;
        dram_count++;

        return dram_count;
}
EXPORT_SYMBOL_GPL(tegra_mc_get_emem_device_count);

#if defined(CONFIG_ARCH_TEGRA_3x_SOC) || \
    defined(CONFIG_ARCH_TEGRA_114_SOC) || \
    defined(CONFIG_ARCH_TEGRA_124_SOC) || \
    defined(CONFIG_ARCH_TEGRA_132_SOC) || \
    defined(CONFIG_ARCH_TEGRA_210_SOC)
static int tegra_mc_setup_latency_allowance(struct tegra_mc *mc)
{
        unsigned long long tick;
        unsigned int i;
        u32 value;

        /* compute the number of MC clock cycles per tick */
        tick = (unsigned long long)mc->tick * clk_get_rate(mc->clk);
        do_div(tick, NSEC_PER_SEC);

        value = mc_readl(mc, MC_EMEM_ARB_CFG);
        value &= ~MC_EMEM_ARB_CFG_CYCLES_PER_UPDATE_MASK;
        value |= MC_EMEM_ARB_CFG_CYCLES_PER_UPDATE(tick);
        mc_writel(mc, value, MC_EMEM_ARB_CFG);

        /* write latency allowance defaults */
        for (i = 0; i < mc->soc->num_clients; i++) {
                const struct tegra_mc_client *client = &mc->soc->clients[i];
                u32 value;

                value = mc_readl(mc, client->regs.la.reg);
                value &= ~(client->regs.la.mask << client->regs.la.shift);
                value |= (client->regs.la.def & client->regs.la.mask) << client->regs.la.shift;
                mc_writel(mc, value, client->regs.la.reg);
        }

        /* latch new values */
        mc_writel(mc, MC_TIMING_UPDATE, MC_TIMING_CONTROL);

        return 0;
}

static int load_one_timing(struct tegra_mc *mc,
                           struct tegra_mc_timing *timing,
                           struct device_node *node)
{
        int err;
        u32 tmp;

        err = of_property_read_u32(node, "clock-frequency", &tmp);
        if (err) {
                dev_err(mc->dev,
                        "timing %pOFn: failed to read rate\n", node);
                return err;
        }

        timing->rate = tmp;
        timing->emem_data = devm_kcalloc(mc->dev, mc->soc->num_emem_regs,
                                         sizeof(u32), GFP_KERNEL);
        if (!timing->emem_data)
                return -ENOMEM;

        err = of_property_read_u32_array(node, "nvidia,emem-configuration",
                                         timing->emem_data,
                                         mc->soc->num_emem_regs);
        if (err) {
                dev_err(mc->dev,
                        "timing %pOFn: failed to read EMEM configuration\n",
                        node);
                return err;
        }

        return 0;
}

static int load_timings(struct tegra_mc *mc, struct device_node *node)
{
        struct device_node *child;
        struct tegra_mc_timing *timing;
        int child_count = of_get_child_count(node);
        int i = 0, err;

        mc->timings = devm_kcalloc(mc->dev, child_count, sizeof(*timing),
                                   GFP_KERNEL);
        if (!mc->timings)
                return -ENOMEM;

        mc->num_timings = child_count;

        for_each_child_of_node(node, child) {
                timing = &mc->timings[i++];

                err = load_one_timing(mc, timing, child);
                if (err) {
                        of_node_put(child);
                        return err;
                }
        }

        return 0;
}

static int tegra_mc_setup_timings(struct tegra_mc *mc)
{
        struct device_node *node;
        u32 ram_code, node_ram_code;
        int err;

        ram_code = tegra_read_ram_code();

        mc->num_timings = 0;

        for_each_child_of_node(mc->dev->of_node, node) {
                err = of_property_read_u32(node, "nvidia,ram-code",
                                           &node_ram_code);
                if (err || (node_ram_code != ram_code))
                        continue;

                err = load_timings(mc, node);
                of_node_put(node);
                if (err)
                        return err;
                break;
        }

        if (mc->num_timings == 0)
                dev_warn(mc->dev,
                         "no memory timings for RAM code %u registered\n",
                         ram_code);

        return 0;
}

int tegra30_mc_probe(struct tegra_mc *mc)
{
        int err;

        mc->clk = devm_clk_get_optional(mc->dev, "mc");
        if (IS_ERR(mc->clk)) {
                dev_err(mc->dev, "failed to get MC clock: %ld\n", PTR_ERR(mc->clk));
                return PTR_ERR(mc->clk);
        }

        /* ensure that debug features are disabled */
        mc_writel(mc, 0x00000000, MC_TIMING_CONTROL_DBG);

        err = tegra_mc_setup_latency_allowance(mc);
        if (err < 0) {
                dev_err(mc->dev, "failed to setup latency allowance: %d\n", err);
                return err;
        }

        err = tegra_mc_setup_timings(mc);
        if (err < 0) {
                dev_err(mc->dev, "failed to setup timings: %d\n", err);
                return err;
        }

        return 0;
}

static irqreturn_t tegra30_mc_handle_irq(int irq, void *data)
{
        struct tegra_mc *mc = data;
        unsigned long status;
        unsigned int bit;

        /* mask all interrupts to avoid flooding */
        status = mc_readl(mc, MC_INTSTATUS) & mc->soc->intmask;
        if (!status)
                return IRQ_NONE;

        for_each_set_bit(bit, &status, 32) {
                const char *error = tegra_mc_status_names[bit] ?: "unknown";
                const char *client = "unknown", *desc;
                const char *direction, *secure;
                phys_addr_t addr = 0;
                unsigned int i;
                char perm[7];
                u8 id, type;
                u32 value;

                value = mc_readl(mc, MC_ERR_STATUS);

#ifdef CONFIG_PHYS_ADDR_T_64BIT
                if (mc->soc->num_address_bits > 32) {
                        addr = ((value >> MC_ERR_STATUS_ADR_HI_SHIFT) &
                                MC_ERR_STATUS_ADR_HI_MASK);
                        addr <<= 32;
                }
#endif

                if (value & MC_ERR_STATUS_RW)
                        direction = "write";
                else
                        direction = "read";

                if (value & MC_ERR_STATUS_SECURITY)
                        secure = "secure ";
                else
                        secure = "";

                id = value & mc->soc->client_id_mask;

                for (i = 0; i < mc->soc->num_clients; i++) {
                        if (mc->soc->clients[i].id == id) {
                                client = mc->soc->clients[i].name;
                                break;
                        }
                }

                type = (value & MC_ERR_STATUS_TYPE_MASK) >>
                       MC_ERR_STATUS_TYPE_SHIFT;
                desc = tegra_mc_error_names[type];

                switch (value & MC_ERR_STATUS_TYPE_MASK) {
                case MC_ERR_STATUS_TYPE_INVALID_SMMU_PAGE:
                        perm[0] = ' ';
                        perm[1] = '[';

                        if (value & MC_ERR_STATUS_READABLE)
                                perm[2] = 'R';
                        else
                                perm[2] = '-';

                        if (value & MC_ERR_STATUS_WRITABLE)
                                perm[3] = 'W';
                        else
                                perm[3] = '-';

                        if (value & MC_ERR_STATUS_NONSECURE)
                                perm[4] = '-';
                        else
                                perm[4] = 'S';

                        perm[5] = ']';
                        perm[6] = '\0';
                        break;

                default:
                        perm[0] = '\0';
                        break;
                }

                value = mc_readl(mc, MC_ERR_ADR);
                addr |= value;

                dev_err_ratelimited(mc->dev, "%s: %s%s @%pa: %s (%s%s)\n",
                                    client, secure, direction, &addr, error,
                                    desc, perm);
        }

        /* clear interrupts */
        mc_writel(mc, status, MC_INTSTATUS);

        return IRQ_HANDLED;
}

const struct tegra_mc_ops tegra30_mc_ops = {
        .probe = tegra30_mc_probe,
        .handle_irq = tegra30_mc_handle_irq,
};
#endif

const char *const tegra_mc_status_names[32] = {
        [ 1] = "External interrupt",
        [ 6] = "EMEM address decode error",
        [ 7] = "GART page fault",
        [ 8] = "Security violation",
        [ 9] = "EMEM arbitration error",
        [10] = "Page fault",
        [11] = "Invalid APB ASID update",
        [12] = "VPR violation",
        [13] = "Secure carveout violation",
        [16] = "MTS carveout violation",
};

const char *const tegra_mc_error_names[8] = {
        [2] = "EMEM decode error",
        [3] = "TrustZone violation",
        [4] = "Carveout violation",
        [6] = "SMMU translation error",
};

/*
 * Memory Controller (MC) has few Memory Clients that are issuing memory
 * bandwidth allocation requests to the MC interconnect provider. The MC
 * provider aggregates the requests and then sends the aggregated request
 * up to the External Memory Controller (EMC) interconnect provider which
 * re-configures hardware interface to External Memory (EMEM) in accordance
 * to the required bandwidth. Each MC interconnect node represents an
 * individual Memory Client.
 *
 * Memory interconnect topology:
 *
 *               +----+
 * +--------+    |    |
 * | TEXSRD +--->+    |
 * +--------+    |    |
 *               |    |    +-----+    +------+
 *    ...        | MC +--->+ EMC +--->+ EMEM |
 *               |    |    +-----+    +------+
 * +--------+    |    |
 * | DISP.. +--->+    |
 * +--------+    |    |
 *               +----+
 */
static int tegra_mc_interconnect_setup(struct tegra_mc *mc)
{
        struct icc_node *node;
        unsigned int i;
        int err;

        /* older device-trees don't have interconnect properties */
        if (!device_property_present(mc->dev, "#interconnect-cells") ||
            !mc->soc->icc_ops)
                return 0;

        mc->provider.dev = mc->dev;
        mc->provider.data = &mc->provider;
        mc->provider.set = mc->soc->icc_ops->set;
        mc->provider.aggregate = mc->soc->icc_ops->aggregate;
        mc->provider.xlate_extended = mc->soc->icc_ops->xlate_extended;

        err = icc_provider_add(&mc->provider);
        if (err)
                return err;

        /* create Memory Controller node */
        node = icc_node_create(TEGRA_ICC_MC);
        if (IS_ERR(node)) {
                err = PTR_ERR(node);
                goto del_provider;
        }

        node->name = "Memory Controller";
        icc_node_add(node, &mc->provider);

        /* link Memory Controller to External Memory Controller */
        err = icc_link_create(node, TEGRA_ICC_EMC);
        if (err)
                goto remove_nodes;

        for (i = 0; i < mc->soc->num_clients; i++) {
                /* create MC client node */
                node = icc_node_create(mc->soc->clients[i].id);
                if (IS_ERR(node)) {
                        err = PTR_ERR(node);
                        goto remove_nodes;
                }

                node->name = mc->soc->clients[i].name;
                icc_node_add(node, &mc->provider);

                /* link Memory Client to Memory Controller */
                err = icc_link_create(node, TEGRA_ICC_MC);
                if (err)
                        goto remove_nodes;
        }

        /*
         * MC driver is registered too early, so early that generic driver
         * syncing doesn't work for the MC. But it doesn't really matter
         * since syncing works for the EMC drivers, hence we can sync the
         * MC driver by ourselves and then EMC will complete syncing of
         * the whole ICC state.
         */
        icc_sync_state(mc->dev);

        return 0;

remove_nodes:
        icc_nodes_remove(&mc->provider);
del_provider:
        icc_provider_del(&mc->provider);

        return err;
}

static int tegra_mc_probe(struct platform_device *pdev)
{
        struct resource *res;
        struct tegra_mc *mc;
        u64 mask;
        int err;

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

        platform_set_drvdata(pdev, mc);
        spin_lock_init(&mc->lock);
        mc->soc = of_device_get_match_data(&pdev->dev);
        mc->dev = &pdev->dev;

        mask = DMA_BIT_MASK(mc->soc->num_address_bits);

        err = dma_coerce_mask_and_coherent(&pdev->dev, mask);
        if (err < 0) {
                dev_err(&pdev->dev, "failed to set DMA mask: %d\n", err);
                return err;
        }

        /* length of MC tick in nanoseconds */
        mc->tick = 30;

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        mc->regs = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(mc->regs))
                return PTR_ERR(mc->regs);

        mc->debugfs.root = debugfs_create_dir("mc", NULL);

        if (mc->soc->ops && mc->soc->ops->probe) {
                err = mc->soc->ops->probe(mc);
                if (err < 0)
                        return err;
        }

        if (mc->soc->ops && mc->soc->ops->handle_irq) {
                mc->irq = platform_get_irq(pdev, 0);
                if (mc->irq < 0)
                        return mc->irq;

                WARN(!mc->soc->client_id_mask, "missing client ID mask for this SoC\n");

                mc_writel(mc, mc->soc->intmask, MC_INTMASK);

                err = devm_request_irq(&pdev->dev, mc->irq, mc->soc->ops->handle_irq, 0,
                                       dev_name(&pdev->dev), mc);
                if (err < 0) {
                        dev_err(&pdev->dev, "failed to request IRQ#%u: %d\n", mc->irq,
                                err);
                        return err;
                }
        }

        if (mc->soc->reset_ops) {
                err = tegra_mc_reset_setup(mc);
                if (err < 0)
                        dev_err(&pdev->dev, "failed to register reset controller: %d\n", err);
        }

        err = tegra_mc_interconnect_setup(mc);
        if (err < 0)
                dev_err(&pdev->dev, "failed to initialize interconnect: %d\n",
                        err);

        if (IS_ENABLED(CONFIG_TEGRA_IOMMU_SMMU) && mc->soc->smmu) {
                mc->smmu = tegra_smmu_probe(&pdev->dev, mc->soc->smmu, mc);
                if (IS_ERR(mc->smmu)) {
                        dev_err(&pdev->dev, "failed to probe SMMU: %ld\n",
                                PTR_ERR(mc->smmu));
                        mc->smmu = NULL;
                }
        }

        if (IS_ENABLED(CONFIG_TEGRA_IOMMU_GART) && !mc->soc->smmu) {
                mc->gart = tegra_gart_probe(&pdev->dev, mc);
                if (IS_ERR(mc->gart)) {
                        dev_err(&pdev->dev, "failed to probe GART: %ld\n",
                                PTR_ERR(mc->gart));
                        mc->gart = NULL;
                }
        }

        return 0;
}

static int __maybe_unused tegra_mc_suspend(struct device *dev)
{
        struct tegra_mc *mc = dev_get_drvdata(dev);

        if (mc->soc->ops && mc->soc->ops->suspend)
                return mc->soc->ops->suspend(mc);

        return 0;
}

static int __maybe_unused tegra_mc_resume(struct device *dev)
{
        struct tegra_mc *mc = dev_get_drvdata(dev);

        if (mc->soc->ops && mc->soc->ops->resume)
                return mc->soc->ops->resume(mc);

        return 0;
}

static const struct dev_pm_ops tegra_mc_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(tegra_mc_suspend, tegra_mc_resume)
};

static struct platform_driver tegra_mc_driver = {
        .driver = {
                .name = "tegra-mc",
                .of_match_table = tegra_mc_of_match,
                .pm = &tegra_mc_pm_ops,
                .suppress_bind_attrs = true,
        },
        .prevent_deferred_probe = true,
        .probe = tegra_mc_probe,
};

static int tegra_mc_init(void)
{
        return platform_driver_register(&tegra_mc_driver);
}
arch_initcall(tegra_mc_init);

MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
MODULE_DESCRIPTION("NVIDIA Tegra Memory Controller driver");
MODULE_LICENSE("GPL v2");