mirror of https://gitee.com/openkylin/linux.git
91 lines
2.1 KiB
C
91 lines
2.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (c) 2020, NVIDIA CORPORATION. All rights reserved.
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*/
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#include <linux/of_reserved_mem.h>
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#include "tegra210-emc.h"
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#define TEGRA_EMC_MAX_FREQS 16
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static int tegra210_emc_table_device_init(struct reserved_mem *rmem,
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struct device *dev)
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{
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struct tegra210_emc *emc = dev_get_drvdata(dev);
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struct tegra210_emc_timing *timings;
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unsigned int i, count = 0;
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timings = memremap(rmem->base, rmem->size, MEMREMAP_WB);
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if (!timings) {
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dev_err(dev, "failed to map EMC table\n");
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return -ENOMEM;
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}
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count = 0;
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for (i = 0; i < TEGRA_EMC_MAX_FREQS; i++) {
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if (timings[i].revision == 0)
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break;
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count++;
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}
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/* only the nominal and derated tables are expected */
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if (emc->derated) {
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dev_warn(dev, "excess EMC table '%s'\n", rmem->name);
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goto out;
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}
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if (emc->nominal) {
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if (count != emc->num_timings) {
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dev_warn(dev, "%u derated vs. %u nominal entries\n",
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count, emc->num_timings);
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memunmap(timings);
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return -EINVAL;
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}
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emc->derated = timings;
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} else {
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emc->num_timings = count;
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emc->nominal = timings;
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}
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out:
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/* keep track of which table this is */
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rmem->priv = timings;
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return 0;
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}
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static void tegra210_emc_table_device_release(struct reserved_mem *rmem,
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struct device *dev)
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{
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struct tegra210_emc_timing *timings = rmem->priv;
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struct tegra210_emc *emc = dev_get_drvdata(dev);
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if ((emc->nominal && timings != emc->nominal) &&
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(emc->derated && timings != emc->derated))
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dev_warn(dev, "trying to release unassigned EMC table '%s'\n",
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rmem->name);
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memunmap(timings);
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}
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static const struct reserved_mem_ops tegra210_emc_table_ops = {
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.device_init = tegra210_emc_table_device_init,
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.device_release = tegra210_emc_table_device_release,
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};
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static int tegra210_emc_table_init(struct reserved_mem *rmem)
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{
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pr_debug("Tegra210 EMC table at %pa, size %lu bytes\n", &rmem->base,
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(unsigned long)rmem->size);
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rmem->ops = &tegra210_emc_table_ops;
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return 0;
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}
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RESERVEDMEM_OF_DECLARE(tegra210_emc_table, "nvidia,tegra210-emc-table",
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tegra210_emc_table_init);
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