2 * arch/arm/mach-tegra/fuse.c
4 * Copyright (C) 2010 Google, Inc.
5 * Copyright (c) 2013, NVIDIA CORPORATION. All rights reserved.
8 * Colin Cross <ccross@android.com>
10 * This software is licensed under the terms of the GNU General Public
11 * License version 2, as published by the Free Software Foundation, and
12 * may be copied, distributed, and modified under those terms.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
21 #include <linux/clk.h>
22 #include <linux/export.h>
24 #include <linux/kernel.h>
25 #include <linux/random.h>
27 #include <soc/tegra/fuse.h>
34 #define FUSE_UID_LOW 0x108
35 #define FUSE_UID_HIGH 0x10c
37 /* Tegra30 and later */
38 #define FUSE_VENDOR_CODE 0x200
39 #define FUSE_FAB_CODE 0x204
40 #define FUSE_LOT_CODE_0 0x208
41 #define FUSE_LOT_CODE_1 0x20c
42 #define FUSE_WAFER_ID 0x210
43 #define FUSE_X_COORDINATE 0x214
44 #define FUSE_Y_COORDINATE 0x218
46 #define FUSE_SKU_INFO 0x110
48 #define TEGRA20_FUSE_SPARE_BIT 0x200
49 #define TEGRA30_FUSE_SPARE_BIT 0x244
52 int tegra_cpu_process_id;
53 int tegra_core_process_id;
55 int tegra_cpu_speedo_id; /* only exist in Tegra30 and later */
56 int tegra_soc_speedo_id;
57 enum tegra_revision tegra_revision;
59 static struct clk *fuse_clk;
60 static int tegra_fuse_spare_bit;
61 static void (*tegra_init_speedo_data)(void);
63 /* The BCT to use at boot is specified by board straps that can be read
64 * through a APB misc register and decoded. 2 bits, i.e. 4 possible BCTs.
66 int tegra_bct_strapping;
68 #define STRAP_OPT 0x008
69 #define GMI_AD0 (1 << 4)
70 #define GMI_AD1 (1 << 5)
71 #define RAM_ID_MASK (GMI_AD0 | GMI_AD1)
72 #define RAM_CODE_SHIFT 4
74 static const char *tegra_revision_name[TEGRA_REVISION_MAX] = {
75 [TEGRA_REVISION_UNKNOWN] = "unknown",
76 [TEGRA_REVISION_A01] = "A01",
77 [TEGRA_REVISION_A02] = "A02",
78 [TEGRA_REVISION_A03] = "A03",
79 [TEGRA_REVISION_A03p] = "A03 prime",
80 [TEGRA_REVISION_A04] = "A04",
83 static void tegra_fuse_enable_clk(void)
86 fuse_clk = clk_get_sys(NULL, "fuse");
89 clk_prepare_enable(fuse_clk);
92 static void tegra_fuse_disable_clk(void)
96 clk_disable_unprepare(fuse_clk);
99 u32 tegra_fuse_readl(unsigned long offset)
101 return tegra_apb_readl(TEGRA_FUSE_BASE + offset);
104 bool tegra_spare_fuse(int bit)
108 tegra_fuse_enable_clk();
110 ret = tegra_fuse_readl(tegra_fuse_spare_bit + bit * 4);
112 tegra_fuse_disable_clk();
117 static enum tegra_revision tegra_get_revision(u32 id)
119 u32 minor_rev = (id >> 16) & 0xf;
123 return TEGRA_REVISION_A01;
125 return TEGRA_REVISION_A02;
127 if (tegra_chip_id == TEGRA20 &&
128 (tegra_spare_fuse(18) || tegra_spare_fuse(19)))
129 return TEGRA_REVISION_A03p;
131 return TEGRA_REVISION_A03;
133 return TEGRA_REVISION_A04;
135 return TEGRA_REVISION_UNKNOWN;
139 static void tegra_get_process_id(void)
143 tegra_fuse_enable_clk();
145 reg = tegra_fuse_readl(tegra_fuse_spare_bit);
146 tegra_cpu_process_id = (reg >> 6) & 3;
147 reg = tegra_fuse_readl(tegra_fuse_spare_bit);
148 tegra_core_process_id = (reg >> 12) & 3;
150 tegra_fuse_disable_clk();
153 u32 tegra_read_chipid(void)
155 return readl_relaxed(IO_ADDRESS(TEGRA_APB_MISC_BASE) + 0x804);
158 static void __init tegra20_fuse_init_randomness(void)
162 randomness[0] = tegra_fuse_readl(FUSE_UID_LOW);
163 randomness[1] = tegra_fuse_readl(FUSE_UID_HIGH);
165 add_device_randomness(randomness, sizeof(randomness));
168 /* Applies to Tegra30 or later */
169 static void __init tegra30_fuse_init_randomness(void)
173 randomness[0] = tegra_fuse_readl(FUSE_VENDOR_CODE);
174 randomness[1] = tegra_fuse_readl(FUSE_FAB_CODE);
175 randomness[2] = tegra_fuse_readl(FUSE_LOT_CODE_0);
176 randomness[3] = tegra_fuse_readl(FUSE_LOT_CODE_1);
177 randomness[4] = tegra_fuse_readl(FUSE_WAFER_ID);
178 randomness[5] = tegra_fuse_readl(FUSE_X_COORDINATE);
179 randomness[6] = tegra_fuse_readl(FUSE_Y_COORDINATE);
181 add_device_randomness(randomness, sizeof(randomness));
184 void __init tegra_init_fuse(void)
189 u32 reg = readl(IO_ADDRESS(TEGRA_CLK_RESET_BASE + 0x48));
191 writel(reg, IO_ADDRESS(TEGRA_CLK_RESET_BASE + 0x48));
194 * Enable FUSE clock. This needs to be hardcoded because the clock
195 * subsystem is not active during early boot.
197 reg = readl(IO_ADDRESS(TEGRA_CLK_RESET_BASE + 0x14));
199 writel(reg, IO_ADDRESS(TEGRA_CLK_RESET_BASE + 0x14));
200 fuse_clk = ERR_PTR(-EINVAL);
202 reg = tegra_fuse_readl(FUSE_SKU_INFO);
204 tegra_sku_id = reg & 0xFF;
206 reg = tegra_apb_readl(TEGRA_APB_MISC_BASE + STRAP_OPT);
208 tegra_bct_strapping = (reg & RAM_ID_MASK) >> RAM_CODE_SHIFT;
210 id = tegra_read_chipid();
212 tegra_chip_id = (id >> 8) & 0xff;
214 switch (tegra_chip_id) {
216 tegra_fuse_spare_bit = TEGRA20_FUSE_SPARE_BIT;
217 tegra_init_speedo_data = &tegra20_init_speedo_data;
220 tegra_fuse_spare_bit = TEGRA30_FUSE_SPARE_BIT;
221 tegra_init_speedo_data = &tegra30_init_speedo_data;
224 tegra_init_speedo_data = &tegra114_init_speedo_data;
227 pr_warn("Tegra: unknown chip id %d\n", tegra_chip_id);
228 tegra_fuse_spare_bit = TEGRA20_FUSE_SPARE_BIT;
229 tegra_init_speedo_data = &tegra_get_process_id;
232 tegra_revision = tegra_get_revision(id);
233 tegra_init_speedo_data();
234 randomness[3] = (tegra_cpu_process_id << 16) | tegra_core_process_id;
235 randomness[4] = (tegra_cpu_speedo_id << 16) | tegra_soc_speedo_id;
237 add_device_randomness(randomness, sizeof(randomness));
238 switch (tegra_chip_id) {
240 tegra20_fuse_init_randomness();
245 tegra30_fuse_init_randomness();
249 pr_info("Tegra Revision: %s SKU: %d CPU Process: %d Core Process: %d\n",
250 tegra_revision_name[tegra_revision],
251 tegra_sku_id, tegra_cpu_process_id,
252 tegra_core_process_id);