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Diffstat (limited to 'drivers/memory/tegra/tegra210-emc-table.c')
-rw-r--r--drivers/memory/tegra/tegra210-emc-table.c88
1 files changed, 88 insertions, 0 deletions
diff --git a/drivers/memory/tegra/tegra210-emc-table.c b/drivers/memory/tegra/tegra210-emc-table.c
new file mode 100644
index 0000000000..34a8785d28
--- /dev/null
+++ b/drivers/memory/tegra/tegra210-emc-table.c
@@ -0,0 +1,88 @@
+// 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 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);