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 for (i = 0; i < TEGRA_EMC_MAX_FREQS; i++) { 26 if (timings[i].revision == 0) 27 break; 28 29 count++; 30 } 31 32 /* only the nominal and derated tables are expected */ 33 if (emc->derated) { 34 dev_warn(dev, "excess EMC table '%s'\n", rmem->name); 35 goto out; 36 } 37 38 if (emc->nominal) { 39 if (count != emc->num_timings) { 40 dev_warn(dev, "%u derated vs. %u nominal entries\n", 41 count, emc->num_timings); 42 memunmap(timings); 43 return -EINVAL; 44 } 45 46 emc->derated = timings; 47 } else { 48 emc->num_timings = count; 49 emc->nominal = timings; 50 } 51 52 out: 53 /* keep track of which table this is */ 54 rmem->priv = timings; 55 56 return 0; 57 } 58 59 static void tegra210_emc_table_device_release(struct reserved_mem *rmem, 60 struct device *dev) 61 { 62 struct tegra210_emc_timing *timings = rmem->priv; 63 struct tegra210_emc *emc = dev_get_drvdata(dev); 64 65 if ((emc->nominal && timings != emc->nominal) && 66 (emc->derated && timings != emc->derated)) 67 dev_warn(dev, "trying to release unassigned EMC table '%s'\n", 68 rmem->name); 69 70 memunmap(timings); 71 } 72 73 static const struct reserved_mem_ops tegra210_emc_table_ops = { 74 .device_init = tegra210_emc_table_device_init, 75 .device_release = tegra210_emc_table_device_release, 76 }; 77 78 static int tegra210_emc_table_init(struct reserved_mem *rmem) 79 { 80 pr_debug("Tegra210 EMC table at %pa, size %lu bytes\n", &rmem->base, 81 (unsigned long)rmem->size); 82 83 rmem->ops = &tegra210_emc_table_ops; 84 85 return 0; 86 } 87 RESERVEDMEM_OF_DECLARE(tegra210_emc_table, "nvidia,tegra210-emc-table", 88 tegra210_emc_table_init); 89