1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2014, NVIDIA CORPORATION.  All rights reserved.
4  */
5 
6 #include <linux/kernel.h>
7 #include <linux/of.h>
8 #include <linux/of_address.h>
9 #include <linux/io.h>
10 
11 #include <soc/tegra/fuse.h>
12 #include <soc/tegra/common.h>
13 
14 #include "fuse.h"
15 
16 #define FUSE_SKU_INFO	0x10
17 
18 #define PMC_STRAPPING_OPT_A_RAM_CODE_SHIFT	4
19 #define PMC_STRAPPING_OPT_A_RAM_CODE_MASK_LONG	\
20 	(0xf << PMC_STRAPPING_OPT_A_RAM_CODE_SHIFT)
21 #define PMC_STRAPPING_OPT_A_RAM_CODE_MASK_SHORT	\
22 	(0x3 << PMC_STRAPPING_OPT_A_RAM_CODE_SHIFT)
23 
24 static bool long_ram_code;
25 static u32 strapping;
26 static u32 chipid;
27 
28 u32 tegra_read_chipid(void)
29 {
30 	WARN(!chipid, "Tegra APB MISC not yet available\n");
31 
32 	return chipid;
33 }
34 
35 u8 tegra_get_chip_id(void)
36 {
37 	return (tegra_read_chipid() >> 8) & 0xff;
38 }
39 
40 u8 tegra_get_major_rev(void)
41 {
42 	return (tegra_read_chipid() >> 4) & 0xf;
43 }
44 
45 u8 tegra_get_minor_rev(void)
46 {
47 	return (tegra_read_chipid() >> 16) & 0xf;
48 }
49 
50 u8 tegra_get_platform(void)
51 {
52 	return (tegra_read_chipid() >> 20) & 0xf;
53 }
54 
55 bool tegra_is_silicon(void)
56 {
57 	switch (tegra_get_chip_id()) {
58 	case TEGRA194:
59 	case TEGRA234:
60 		if (tegra_get_platform() == 0)
61 			return true;
62 
63 		return false;
64 	}
65 
66 	/*
67 	 * Chips prior to Tegra194 have a different way of determining whether
68 	 * they are silicon or not. Since we never supported simulation on the
69 	 * older Tegra chips, don't bother extracting the information and just
70 	 * report that we're running on silicon.
71 	 */
72 	return true;
73 }
74 
75 u32 tegra_read_straps(void)
76 {
77 	WARN(!chipid, "Tegra ABP MISC not yet available\n");
78 
79 	return strapping;
80 }
81 
82 u32 tegra_read_ram_code(void)
83 {
84 	u32 straps = tegra_read_straps();
85 
86 	if (long_ram_code)
87 		straps &= PMC_STRAPPING_OPT_A_RAM_CODE_MASK_LONG;
88 	else
89 		straps &= PMC_STRAPPING_OPT_A_RAM_CODE_MASK_SHORT;
90 
91 	return straps >> PMC_STRAPPING_OPT_A_RAM_CODE_SHIFT;
92 }
93 
94 static const struct of_device_id apbmisc_match[] __initconst = {
95 	{ .compatible = "nvidia,tegra20-apbmisc", },
96 	{ .compatible = "nvidia,tegra186-misc", },
97 	{ .compatible = "nvidia,tegra194-misc", },
98 	{ .compatible = "nvidia,tegra234-misc", },
99 	{},
100 };
101 
102 void __init tegra_init_revision(void)
103 {
104 	u8 chip_id, minor_rev;
105 
106 	chip_id = tegra_get_chip_id();
107 	minor_rev = tegra_get_minor_rev();
108 
109 	switch (minor_rev) {
110 	case 1:
111 		tegra_sku_info.revision = TEGRA_REVISION_A01;
112 		break;
113 	case 2:
114 		tegra_sku_info.revision = TEGRA_REVISION_A02;
115 		break;
116 	case 3:
117 		if (chip_id == TEGRA20 && (tegra_fuse_read_spare(18) ||
118 					   tegra_fuse_read_spare(19)))
119 			tegra_sku_info.revision = TEGRA_REVISION_A03p;
120 		else
121 			tegra_sku_info.revision = TEGRA_REVISION_A03;
122 		break;
123 	case 4:
124 		tegra_sku_info.revision = TEGRA_REVISION_A04;
125 		break;
126 	default:
127 		tegra_sku_info.revision = TEGRA_REVISION_UNKNOWN;
128 	}
129 
130 	tegra_sku_info.sku_id = tegra_fuse_read_early(FUSE_SKU_INFO);
131 }
132 
133 void __init tegra_init_apbmisc(void)
134 {
135 	void __iomem *apbmisc_base, *strapping_base;
136 	struct resource apbmisc, straps;
137 	struct device_node *np;
138 
139 	np = of_find_matching_node(NULL, apbmisc_match);
140 	if (!np) {
141 		/*
142 		 * Fall back to legacy initialization for 32-bit ARM only. All
143 		 * 64-bit ARM device tree files for Tegra are required to have
144 		 * an APBMISC node.
145 		 *
146 		 * This is for backwards-compatibility with old device trees
147 		 * that didn't contain an APBMISC node.
148 		 */
149 		if (IS_ENABLED(CONFIG_ARM) && soc_is_tegra()) {
150 			/* APBMISC registers (chip revision, ...) */
151 			apbmisc.start = 0x70000800;
152 			apbmisc.end = 0x70000863;
153 			apbmisc.flags = IORESOURCE_MEM;
154 
155 			/* strapping options */
156 			if (of_machine_is_compatible("nvidia,tegra124")) {
157 				straps.start = 0x7000e864;
158 				straps.end = 0x7000e867;
159 			} else {
160 				straps.start = 0x70000008;
161 				straps.end = 0x7000000b;
162 			}
163 
164 			straps.flags = IORESOURCE_MEM;
165 
166 			pr_warn("Using APBMISC region %pR\n", &apbmisc);
167 			pr_warn("Using strapping options registers %pR\n",
168 				&straps);
169 		} else {
170 			/*
171 			 * At this point we're not running on Tegra, so play
172 			 * nice with multi-platform kernels.
173 			 */
174 			return;
175 		}
176 	} else {
177 		/*
178 		 * Extract information from the device tree if we've found a
179 		 * matching node.
180 		 */
181 		if (of_address_to_resource(np, 0, &apbmisc) < 0) {
182 			pr_err("failed to get APBMISC registers\n");
183 			return;
184 		}
185 
186 		if (of_address_to_resource(np, 1, &straps) < 0) {
187 			pr_err("failed to get strapping options registers\n");
188 			return;
189 		}
190 	}
191 
192 	apbmisc_base = ioremap(apbmisc.start, resource_size(&apbmisc));
193 	if (!apbmisc_base) {
194 		pr_err("failed to map APBMISC registers\n");
195 	} else {
196 		chipid = readl_relaxed(apbmisc_base + 4);
197 		iounmap(apbmisc_base);
198 	}
199 
200 	strapping_base = ioremap(straps.start, resource_size(&straps));
201 	if (!strapping_base) {
202 		pr_err("failed to map strapping options registers\n");
203 	} else {
204 		strapping = readl_relaxed(strapping_base);
205 		iounmap(strapping_base);
206 	}
207 
208 	long_ram_code = of_property_read_bool(np, "nvidia,long-ram-code");
209 }
210