// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2020, NVIDIA CORPORATION.  All rights reserved.
 */

#include <linux/of_reserved_mem.h>

#include "tegra210-emc.h"

#define TEGRA_EMC_MAX_FREQS             16

static int tegra210_emc_table_device_init(struct reserved_mem *rmem,
                                          struct device *dev)
{
        struct tegra210_emc *emc = dev_get_drvdata(dev);
        struct tegra210_emc_timing *timings;
        unsigned int i, count = 0;

        timings = memremap(rmem->base, rmem->size, MEMREMAP_WB);
        if (!timings) {
                dev_err(dev, "failed to map EMC table\n");
                return -ENOMEM;
        }

        for (i = 0; i < TEGRA_EMC_MAX_FREQS; i++) {
                if (timings[i].revision == 0)
                        break;

                count++;
        }

        /* only the nominal and derated tables are expected */
        if (emc->derated) {
                dev_warn(dev, "excess EMC table '%s'\n", rmem->name);
                goto out;
        }

        if (emc->nominal) {
                if (count != emc->num_timings) {
                        dev_warn(dev, "%u derated vs. %u nominal entries\n",
                                 count, emc->num_timings);
                        memunmap(timings);
                        return -EINVAL;
                }

                emc->derated = timings;
        } else {
                emc->num_timings = count;
                emc->nominal = timings;
        }

out:
        /* keep track of which table this is */
        rmem->priv = timings;

        return 0;
}

static void tegra210_emc_table_device_release(struct reserved_mem *rmem,
                                              struct device *dev)
{
        struct tegra210_emc_timing *timings = rmem->priv;
        struct tegra210_emc *emc = dev_get_drvdata(dev);

        if ((emc->nominal && timings != emc->nominal) &&
            (emc->derated && timings != emc->derated))
                dev_warn(dev, "trying to release unassigned EMC table '%s'\n",
                         rmem->name);

        memunmap(timings);
}

static int tegra210_emc_table_init(unsigned long node,
                                   struct reserved_mem *rmem)
{
        pr_debug("Tegra210 EMC table at %pa, size %lu bytes\n", &rmem->base,
                 (unsigned long)rmem->size);

        return 0;
}

static const struct reserved_mem_ops tegra210_emc_table_ops = {
        .node_init = tegra210_emc_table_init,
        .device_init = tegra210_emc_table_device_init,
        .device_release = tegra210_emc_table_device_release,
};

RESERVEDMEM_OF_DECLARE(tegra210_emc_table, "nvidia,tegra210-emc-table",
                       &tegra210_emc_table_ops);