1 files changed, 90 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 000000000..3e0598363
--- /dev/null
+++ b/drivers/memory/tegra/tegra210-emc-table.c
@@ -0,0 +1,90 @@
+// 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);