1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2021 Sean Anderson <sean.anderson@seco.com>
4 */
5
6 #include <dm.h>
7 #include <log.h>
8 #include <sysinfo.h>
9 #include <asm/gpio.h>
10 #include <dm/device_compat.h>
11
12 /**
13 * struct sysinfo_gpio_priv - GPIO sysinfo private data
14 * @gpios: List of GPIOs used to detect the revision
15 * @gpio_num: The number of GPIOs in @gpios
16 * @revision: The revision as detected from the GPIOs.
17 */
18 struct sysinfo_gpio_priv {
19 struct gpio_desc *gpios;
20 int gpio_num, revision;
21 };
22
sysinfo_gpio_detect(struct udevice * dev)23 static int sysinfo_gpio_detect(struct udevice *dev)
24 {
25 int ret;
26 struct sysinfo_gpio_priv *priv = dev_get_priv(dev);
27
28 ret = dm_gpio_get_values_as_int_base3(priv->gpios, priv->gpio_num);
29 if (ret < 0)
30 return ret;
31
32 priv->revision = ret;
33 return 0;
34 }
35
sysinfo_gpio_get_int(struct udevice * dev,int id,int * val)36 static int sysinfo_gpio_get_int(struct udevice *dev, int id, int *val)
37 {
38 struct sysinfo_gpio_priv *priv = dev_get_priv(dev);
39
40 switch (id) {
41 case SYSID_BOARD_MODEL:
42 *val = priv->revision;
43 return 0;
44 default:
45 return -EINVAL;
46 };
47 }
48
sysinfo_gpio_get_str(struct udevice * dev,int id,size_t size,char * val)49 static int sysinfo_gpio_get_str(struct udevice *dev, int id, size_t size, char *val)
50 {
51 struct sysinfo_gpio_priv *priv = dev_get_priv(dev);
52
53 switch (id) {
54 case SYSID_BOARD_MODEL: {
55 const char *name = NULL;
56 int i, ret;
57 u32 revision;
58
59 for (i = 0; ; i++) {
60 ret = dev_read_u32_index(dev, "revisions", i,
61 &revision);
62 if (ret) {
63 if (ret != -EOVERFLOW)
64 return ret;
65 break;
66 }
67
68 if (revision == priv->revision) {
69 ret = dev_read_string_index(dev, "names", i,
70 &name);
71 if (ret < 0)
72 return ret;
73 break;
74 }
75 }
76 if (!name)
77 name = "unknown";
78
79 strncpy(val, name, size);
80 val[size - 1] = '\0';
81 return 0;
82 }
83 default:
84 return -EINVAL;
85 };
86 }
87
88 static const struct sysinfo_ops sysinfo_gpio_ops = {
89 .detect = sysinfo_gpio_detect,
90 .get_int = sysinfo_gpio_get_int,
91 .get_str = sysinfo_gpio_get_str,
92 };
93
sysinfo_gpio_probe(struct udevice * dev)94 static int sysinfo_gpio_probe(struct udevice *dev)
95 {
96 int ret;
97 struct sysinfo_gpio_priv *priv = dev_get_priv(dev);
98
99 priv->gpio_num = gpio_get_list_count(dev, "gpios");
100 if (priv->gpio_num < 0) {
101 dev_err(dev, "could not get gpios length (err = %d)\n",
102 priv->gpio_num);
103 return priv->gpio_num;
104 }
105
106 priv->gpios = calloc(priv->gpio_num, sizeof(*priv->gpios));
107 if (!priv->gpios) {
108 dev_err(dev, "could not allocate memory for %d gpios\n",
109 priv->gpio_num);
110 return -ENOMEM;
111 }
112
113 ret = gpio_request_list_by_name(dev, "gpios", priv->gpios,
114 priv->gpio_num, GPIOD_IS_IN);
115 if (ret != priv->gpio_num) {
116 dev_err(dev, "could not get gpios (err = %d)\n",
117 priv->gpio_num);
118 return ret;
119 }
120
121 if (!dev_read_bool(dev, "revisions") || !dev_read_bool(dev, "names")) {
122 dev_err(dev, "revisions or names properties missing\n");
123 return -ENOENT;
124 }
125
126 return 0;
127 }
128
129 static const struct udevice_id sysinfo_gpio_ids[] = {
130 { .compatible = "gpio-sysinfo" },
131 { /* sentinel */ }
132 };
133
134 U_BOOT_DRIVER(sysinfo_gpio) = {
135 .name = "sysinfo_gpio",
136 .id = UCLASS_SYSINFO,
137 .of_match = sysinfo_gpio_ids,
138 .ops = &sysinfo_gpio_ops,
139 .priv_auto = sizeof(struct sysinfo_gpio_priv),
140 .probe = sysinfo_gpio_probe,
141 };
142