1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2017 Theobroma Systems Design und Consulting GmbH
4 */
5
6 #include <common.h>
7 #include <dm.h>
8 #include <log.h>
9 #include <mmc.h>
10 #include <spl.h>
11 #include <asm/global_data.h>
12
13 #if CONFIG_IS_ENABLED(OF_LIBFDT)
14 /**
15 * spl_node_to_boot_device() - maps from a DT-node to a SPL boot device
16 * @node: of_offset of the node
17 *
18 * The SPL framework uses BOOT_DEVICE_... constants to identify its boot
19 * sources. These may take on a device-specific meaning, depending on
20 * what nodes are enabled in a DTS (e.g. BOOT_DEVICE_MMC1 may refer to
21 * different controllers/block-devices, depending on which SD/MMC controllers
22 * are enabled in any given DTS). This function maps from a DT-node back
23 * onto a BOOT_DEVICE_... constant, considering the currently active devices.
24 *
25 * Returns
26 * -ENOENT, if no device matching the node could be found
27 * -ENOSYS, if the device matching the node can not be mapped onto a
28 * SPL boot device (e.g. the third MMC device)
29 * -1, for unspecified failures
30 * a positive integer (from the BOOT_DEVICE_... family) on succes.
31 */
32
spl_node_to_boot_device(int node)33 static int spl_node_to_boot_device(int node)
34 {
35 struct udevice *parent;
36
37 /*
38 * This should eventually move into the SPL code, once SPL becomes
39 * aware of the block-device layer. Until then (and to avoid unneeded
40 * delays in getting this feature out), it lives at the board-level.
41 */
42 if (!uclass_get_device_by_of_offset(UCLASS_MMC, node, &parent)) {
43 struct udevice *dev;
44 struct blk_desc *desc = NULL;
45
46 for (device_find_first_child(parent, &dev);
47 dev;
48 device_find_next_child(&dev)) {
49 if (device_get_uclass_id(dev) == UCLASS_BLK) {
50 desc = dev_get_uclass_plat(dev);
51 break;
52 }
53 }
54
55 if (!desc)
56 return -ENOENT;
57
58 switch (desc->devnum) {
59 case 0:
60 return BOOT_DEVICE_MMC1;
61 case 1:
62 return BOOT_DEVICE_MMC2;
63 default:
64 return -ENOSYS;
65 }
66 } else if (!uclass_get_device_by_of_offset(UCLASS_SPI_FLASH, node,
67 &parent)) {
68 return BOOT_DEVICE_SPI;
69 }
70
71 /*
72 * SPL doesn't differentiate SPI flashes, so we keep the detection
73 * brief and inaccurate... hopefully, the common SPL layer can be
74 * extended with awareness of the BLK layer (and matching OF_CONTROL)
75 * soon.
76 */
77 if (!uclass_get_device_by_of_offset(UCLASS_SPI_FLASH, node, &parent))
78 return BOOT_DEVICE_SPI;
79
80 return -1;
81 }
82
83 /**
84 * board_spl_was_booted_from() - retrieves the of-path the SPL was loaded from
85 *
86 * To support a 'same-as-spl' specification in the search-order for the next
87 * stage, we need a SoC- or board-specific way to handshake with what 'came
88 * before us' (either a BROM or TPL stage) and map the info retrieved onto
89 * a OF path.
90 *
91 * Returns
92 * NULL, on failure or if the device could not be identified
93 * a of_path (a string), on success
94 */
board_spl_was_booted_from(void)95 __weak const char *board_spl_was_booted_from(void)
96 {
97 debug("%s: no support for 'same-as-spl' for this board\n", __func__);
98 return NULL;
99 }
100
board_boot_order(u32 * spl_boot_list)101 void board_boot_order(u32 *spl_boot_list)
102 {
103 /* In case of no fdt (or only plat), use spl_boot_device() */
104 if (!CONFIG_IS_ENABLED(OF_CONTROL) || CONFIG_IS_ENABLED(OF_PLATDATA)) {
105 spl_boot_list[0] = spl_boot_device();
106 return;
107 }
108
109 const void *blob = gd->fdt_blob;
110 int chosen_node = fdt_path_offset(blob, "/chosen");
111 int idx = 0;
112 int elem;
113 int boot_device;
114 int node;
115 const char *conf;
116
117 if (chosen_node < 0) {
118 debug("%s: /chosen not found, using spl_boot_device()\n",
119 __func__);
120 spl_boot_list[0] = spl_boot_device();
121 return;
122 }
123
124 for (elem = 0;
125 (conf = fdt_stringlist_get(blob, chosen_node,
126 "u-boot,spl-boot-order", elem, NULL));
127 elem++) {
128 const char *alias;
129
130 /* Handle the case of 'same device the SPL was loaded from' */
131 if (strncmp(conf, "same-as-spl", 11) == 0) {
132 conf = board_spl_was_booted_from();
133 if (!conf)
134 continue;
135 }
136
137 /* First check if the list element is an alias */
138 alias = fdt_get_alias(blob, conf);
139 if (alias)
140 conf = alias;
141
142 /* Try to resolve the config item (or alias) as a path */
143 node = fdt_path_offset(blob, conf);
144 if (node < 0) {
145 debug("%s: could not find %s in FDT\n", __func__, conf);
146 continue;
147 }
148
149 /* Try to map this back onto SPL boot devices */
150 boot_device = spl_node_to_boot_device(node);
151 if (boot_device < 0) {
152 debug("%s: could not map node @%x to a boot-device\n",
153 __func__, node);
154 continue;
155 }
156
157 spl_boot_list[idx++] = boot_device;
158 }
159
160 /* If we had no matches, fall back to spl_boot_device */
161 if (idx == 0)
162 spl_boot_list[0] = spl_boot_device();
163 }
164 #endif
165