1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2014-2023, NVIDIA CORPORATION.  All rights reserved.
4  */
5 
6 #include <linux/export.h>
7 #include <linux/io.h>
8 #include <linux/kernel.h>
9 #include <linux/of.h>
10 #include <linux/of_address.h>
11 
12 #include <soc/tegra/common.h>
13 #include <soc/tegra/fuse.h>
14 
15 #include "fuse.h"
16 
17 #define FUSE_SKU_INFO	0x10
18 
19 #define ERD_ERR_CONFIG 0x120c
20 #define ERD_MASK_INBAND_ERR 0x1
21 
22 #define PMC_STRAPPING_OPT_A_RAM_CODE_SHIFT	4
23 #define PMC_STRAPPING_OPT_A_RAM_CODE_MASK_LONG	\
24 	(0xf << PMC_STRAPPING_OPT_A_RAM_CODE_SHIFT)
25 #define PMC_STRAPPING_OPT_A_RAM_CODE_MASK_SHORT	\
26 	(0x3 << PMC_STRAPPING_OPT_A_RAM_CODE_SHIFT)
27 
28 static void __iomem *apbmisc_base;
29 static bool long_ram_code;
30 static u32 strapping;
31 static u32 chipid;
32 
33 u32 tegra_read_chipid(void)
34 {
35 	WARN(!chipid, "Tegra APB MISC not yet available\n");
36 
37 	return chipid;
38 }
39 
40 u8 tegra_get_chip_id(void)
41 {
42 	return (tegra_read_chipid() >> 8) & 0xff;
43 }
44 
45 u8 tegra_get_major_rev(void)
46 {
47 	return (tegra_read_chipid() >> 4) & 0xf;
48 }
49 
50 u8 tegra_get_minor_rev(void)
51 {
52 	return (tegra_read_chipid() >> 16) & 0xf;
53 }
54 
55 u8 tegra_get_platform(void)
56 {
57 	return (tegra_read_chipid() >> 20) & 0xf;
58 }
59 
60 bool tegra_is_silicon(void)
61 {
62 	switch (tegra_get_chip_id()) {
63 	case TEGRA194:
64 	case TEGRA234:
65 	case TEGRA264:
66 		if (tegra_get_platform() == 0)
67 			return true;
68 
69 		return false;
70 	}
71 
72 	/*
73 	 * Chips prior to Tegra194 have a different way of determining whether
74 	 * they are silicon or not. Since we never supported simulation on the
75 	 * older Tegra chips, don't bother extracting the information and just
76 	 * report that we're running on silicon.
77 	 */
78 	return true;
79 }
80 
81 u32 tegra_read_straps(void)
82 {
83 	WARN(!chipid, "Tegra ABP MISC not yet available\n");
84 
85 	return strapping;
86 }
87 
88 u32 tegra_read_ram_code(void)
89 {
90 	u32 straps = tegra_read_straps();
91 
92 	if (long_ram_code)
93 		straps &= PMC_STRAPPING_OPT_A_RAM_CODE_MASK_LONG;
94 	else
95 		straps &= PMC_STRAPPING_OPT_A_RAM_CODE_MASK_SHORT;
96 
97 	return straps >> PMC_STRAPPING_OPT_A_RAM_CODE_SHIFT;
98 }
99 EXPORT_SYMBOL_GPL(tegra_read_ram_code);
100 
101 /*
102  * The function sets ERD(Error Response Disable) bit.
103  * This allows to mask inband errors and always send an
104  * OKAY response from CBB to the master which caused error.
105  */
106 int tegra194_miscreg_mask_serror(void)
107 {
108 	if (!apbmisc_base)
109 		return -EPROBE_DEFER;
110 
111 	if (!of_machine_is_compatible("nvidia,tegra194")) {
112 		WARN(1, "Only supported for Tegra194 devices!\n");
113 		return -EOPNOTSUPP;
114 	}
115 
116 	writel_relaxed(ERD_MASK_INBAND_ERR,
117 		       apbmisc_base + ERD_ERR_CONFIG);
118 
119 	return 0;
120 }
121 EXPORT_SYMBOL(tegra194_miscreg_mask_serror);
122 
123 static const struct of_device_id apbmisc_match[] __initconst = {
124 	{ .compatible = "nvidia,tegra20-apbmisc", },
125 	{ .compatible = "nvidia,tegra186-misc", },
126 	{ .compatible = "nvidia,tegra194-misc", },
127 	{ .compatible = "nvidia,tegra234-misc", },
128 	{},
129 };
130 
131 void __init tegra_init_revision(void)
132 {
133 	u8 chip_id, minor_rev;
134 
135 	chip_id = tegra_get_chip_id();
136 	minor_rev = tegra_get_minor_rev();
137 
138 	switch (minor_rev) {
139 	case 1:
140 		tegra_sku_info.revision = TEGRA_REVISION_A01;
141 		break;
142 	case 2:
143 		tegra_sku_info.revision = TEGRA_REVISION_A02;
144 		break;
145 	case 3:
146 		if (chip_id == TEGRA20 && (tegra_fuse_read_spare(18) ||
147 					   tegra_fuse_read_spare(19)))
148 			tegra_sku_info.revision = TEGRA_REVISION_A03p;
149 		else
150 			tegra_sku_info.revision = TEGRA_REVISION_A03;
151 		break;
152 	case 4:
153 		tegra_sku_info.revision = TEGRA_REVISION_A04;
154 		break;
155 	default:
156 		tegra_sku_info.revision = TEGRA_REVISION_UNKNOWN;
157 	}
158 
159 	tegra_sku_info.sku_id = tegra_fuse_read_early(FUSE_SKU_INFO);
160 	tegra_sku_info.platform = tegra_get_platform();
161 }
162 
163 void __init tegra_init_apbmisc(void)
164 {
165 	void __iomem *strapping_base;
166 	struct resource apbmisc, straps;
167 	struct device_node *np;
168 
169 	np = of_find_matching_node(NULL, apbmisc_match);
170 	if (!np) {
171 		/*
172 		 * Fall back to legacy initialization for 32-bit ARM only. All
173 		 * 64-bit ARM device tree files for Tegra are required to have
174 		 * an APBMISC node.
175 		 *
176 		 * This is for backwards-compatibility with old device trees
177 		 * that didn't contain an APBMISC node.
178 		 */
179 		if (IS_ENABLED(CONFIG_ARM) && soc_is_tegra()) {
180 			/* APBMISC registers (chip revision, ...) */
181 			apbmisc.start = 0x70000800;
182 			apbmisc.end = 0x70000863;
183 			apbmisc.flags = IORESOURCE_MEM;
184 
185 			/* strapping options */
186 			if (of_machine_is_compatible("nvidia,tegra124")) {
187 				straps.start = 0x7000e864;
188 				straps.end = 0x7000e867;
189 			} else {
190 				straps.start = 0x70000008;
191 				straps.end = 0x7000000b;
192 			}
193 
194 			straps.flags = IORESOURCE_MEM;
195 
196 			pr_warn("Using APBMISC region %pR\n", &apbmisc);
197 			pr_warn("Using strapping options registers %pR\n",
198 				&straps);
199 		} else {
200 			/*
201 			 * At this point we're not running on Tegra, so play
202 			 * nice with multi-platform kernels.
203 			 */
204 			return;
205 		}
206 	} else {
207 		/*
208 		 * Extract information from the device tree if we've found a
209 		 * matching node.
210 		 */
211 		if (of_address_to_resource(np, 0, &apbmisc) < 0) {
212 			pr_err("failed to get APBMISC registers\n");
213 			goto put;
214 		}
215 
216 		if (of_address_to_resource(np, 1, &straps) < 0) {
217 			pr_err("failed to get strapping options registers\n");
218 			goto put;
219 		}
220 	}
221 
222 	apbmisc_base = ioremap(apbmisc.start, resource_size(&apbmisc));
223 	if (!apbmisc_base) {
224 		pr_err("failed to map APBMISC registers\n");
225 	} else {
226 		chipid = readl_relaxed(apbmisc_base + 4);
227 	}
228 
229 	strapping_base = ioremap(straps.start, resource_size(&straps));
230 	if (!strapping_base) {
231 		pr_err("failed to map strapping options registers\n");
232 	} else {
233 		strapping = readl_relaxed(strapping_base);
234 		iounmap(strapping_base);
235 	}
236 
237 	long_ram_code = of_property_read_bool(np, "nvidia,long-ram-code");
238 
239 put:
240 	of_node_put(np);
241 }
242