1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2020, NVIDIA CORPORATION. All rights reserved. 4 */ 5 6 #include <linux/of_reserved_mem.h> 7 8 #include "tegra210-emc.h" 9 10 #define TEGRA_EMC_MAX_FREQS 16 11 12 static int tegra210_emc_table_device_init(struct reserved_mem *rmem, 13 struct device *dev) 14 { 15 struct tegra210_emc *emc = dev_get_drvdata(dev); 16 struct tegra210_emc_timing *timings; 17 unsigned int i, count = 0; 18 19 timings = memremap(rmem->base, rmem->size, MEMREMAP_WB); 20 if (!timings) { 21 dev_err(dev, "failed to map EMC table\n"); 22 return -ENOMEM; 23 } 24 25 count = 0; 26 27 for (i = 0; i < TEGRA_EMC_MAX_FREQS; i++) { 28 if (timings[i].revision == 0) 29 break; 30 31 count++; 32 } 33 34 /* only the nominal and derated tables are expected */ 35 if (emc->derated) { 36 dev_warn(dev, "excess EMC table '%s'\n", rmem->name); 37 goto out; 38 } 39 40 if (emc->nominal) { 41 if (count != emc->num_timings) { 42 dev_warn(dev, "%u derated vs. %u nominal entries\n", 43 count, emc->num_timings); 44 memunmap(timings); 45 return -EINVAL; 46 } 47 48 emc->derated = timings; 49 } else { 50 emc->num_timings = count; 51 emc->nominal = timings; 52 } 53 54 out: 55 /* keep track of which table this is */ 56 rmem->priv = timings; 57 58 return 0; 59 } 60 61 static void tegra210_emc_table_device_release(struct reserved_mem *rmem, 62 struct device *dev) 63 { 64 struct tegra210_emc_timing *timings = rmem->priv; 65 struct tegra210_emc *emc = dev_get_drvdata(dev); 66 67 if ((emc->nominal && timings != emc->nominal) && 68 (emc->derated && timings != emc->derated)) 69 dev_warn(dev, "trying to release unassigned EMC table '%s'\n", 70 rmem->name); 71 72 memunmap(timings); 73 } 74 75 static const struct reserved_mem_ops tegra210_emc_table_ops = { 76 .device_init = tegra210_emc_table_device_init, 77 .device_release = tegra210_emc_table_device_release, 78 }; 79 80 static int tegra210_emc_table_init(struct reserved_mem *rmem) 81 { 82 pr_debug("Tegra210 EMC table at %pa, size %lu bytes\n", &rmem->base, 83 (unsigned long)rmem->size); 84 85 rmem->ops = &tegra210_emc_table_ops; 86 87 return 0; 88 } 89 RESERVEDMEM_OF_DECLARE(tegra210_emc_table, "nvidia,tegra210-emc-table", 90 tegra210_emc_table_init); 91