]> Git Repo - linux.git/blob - drivers/memory/tegra/tegra210-emc-table.c
Linux 6.14-rc3
[linux.git] / drivers / memory / tegra / tegra210-emc-table.c
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);
This page took 0.032015 seconds and 4 git commands to generate.