linux/drivers/memory/tegra/tegra210-emc-table.c

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// 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;
}
count = 0;
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 const struct reserved_mem_ops tegra210_emc_table_ops = {
.device_init = tegra210_emc_table_device_init,
.device_release = tegra210_emc_table_device_release,
};
static int tegra210_emc_table_init(struct reserved_mem *rmem)
{
pr_debug("Tegra210 EMC table at %pa, size %lu bytes\n", &rmem->base,
(unsigned long)rmem->size);
rmem->ops = &tegra210_emc_table_ops;
return 0;
}
RESERVEDMEM_OF_DECLARE(tegra210_emc_table, "nvidia,tegra210-emc-table",
tegra210_emc_table_init);