1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2017
4 * Mario Six, Guntermann & Drunck GmbH, mario.six@gdsys.cc
5 */
6
7 #include <dm.h>
8 #include <sysinfo.h>
9 #include <i2c.h>
10 #include <log.h>
11 #include <asm/gpio.h>
12
13 #include "gazerbeam.h"
14
15 /* Sequence number of I2C bus that holds the GPIO expanders */
16 static const int I2C_BUS_SEQ_NO = 1;
17
18 /* I2C address of SC/MC2 expander */
19 static const int MC2_EXPANDER_ADDR = 0x20;
20 /* I2C address of MC4 expander */
21 static const int MC4_EXPANDER_ADDR = 0x22;
22
23 /* Number of the GPIO to read the SC data from */
24 static const int SC_GPIO_NO;
25 /* Number of the GPIO to read the CON data from */
26 static const int CON_GPIO_NO = 1;
27
28 /**
29 * struct sysinfo_gazerbeam_priv - Private data structure for the gazerbeam
30 * sysinfo driver
31 * @reset_gpios: GPIOs for the sysinfo's reset GPIOs.
32 * @var_gpios: GPIOs for the sysinfo's hardware variant GPIOs
33 * @ver_gpios: GPIOs for the sysinfo's hardware version GPIOs
34 * @variant: Container for the sysinfo's hardware variant (CON/CPU)
35 * @multichannel: Container for the sysinfo's multichannel variant (MC4/MC2/SC)
36 * @hwversion: Container for the sysinfo's hardware version
37 */
38 struct sysinfo_gazerbeam_priv {
39 struct gpio_desc reset_gpios[2];
40 struct gpio_desc var_gpios[2];
41 struct gpio_desc ver_gpios[4];
42 int variant;
43 int multichannel;
44 int hwversion;
45 };
46
47 /**
48 * _read_sysinfo_variant_data() - Read variant information from the hardware.
49 * @dev: The sysinfo device for which to determine the multichannel and device
50 * type information.
51 *
52 * The data read from the sysinfo's hardware (mostly hard-wired GPIOs) is stored
53 * in the private data structure of the driver to be used by other driver
54 * methods.
55 *
56 * Return: 0 if OK, -ve on error.
57 */
_read_sysinfo_variant_data(struct udevice * dev)58 static int _read_sysinfo_variant_data(struct udevice *dev)
59 {
60 struct sysinfo_gazerbeam_priv *priv = dev_get_priv(dev);
61 struct udevice *i2c_bus;
62 struct udevice *dummy;
63 char *listname;
64 int mc4, mc2, sc, mc2_sc, con;
65 int gpio_num;
66 int res;
67
68 res = uclass_get_device_by_seq(UCLASS_I2C, I2C_BUS_SEQ_NO, &i2c_bus);
69 if (res) {
70 debug("%s: Could not get I2C bus %d (err = %d)\n",
71 dev->name, I2C_BUS_SEQ_NO, res);
72 return res;
73 }
74
75 if (!i2c_bus) {
76 debug("%s: Could not get I2C bus %d\n",
77 dev->name, I2C_BUS_SEQ_NO);
78 return -EIO;
79 }
80
81 mc2_sc = !dm_i2c_probe(i2c_bus, MC2_EXPANDER_ADDR, 0, &dummy);
82 mc4 = !dm_i2c_probe(i2c_bus, MC4_EXPANDER_ADDR, 0, &dummy);
83
84 if (mc2_sc && mc4) {
85 debug("%s: Board hardware configuration inconsistent.\n",
86 dev->name);
87 return -EINVAL;
88 }
89
90 listname = mc2_sc ? "var-gpios-mc2" : "var-gpios-mc4";
91
92 gpio_num = gpio_request_list_by_name(dev, listname, priv->var_gpios,
93 ARRAY_SIZE(priv->var_gpios),
94 GPIOD_IS_IN);
95 if (gpio_num < 0) {
96 debug("%s: Requesting gpio list %s failed (err = %d).\n",
97 dev->name, listname, gpio_num);
98 return gpio_num;
99 }
100
101 sc = dm_gpio_get_value(&priv->var_gpios[SC_GPIO_NO]);
102 if (sc < 0) {
103 debug("%s: Error while reading 'sc' GPIO (err = %d)",
104 dev->name, sc);
105 return sc;
106 }
107
108 mc2 = mc2_sc ? (sc ? 0 : 1) : 0;
109
110 if ((sc && mc2) || (sc && mc4) || (!sc && !mc2 && !mc4)) {
111 debug("%s: Board hardware configuration inconsistent.\n",
112 dev->name);
113 return -EINVAL;
114 }
115
116 con = dm_gpio_get_value(&priv->var_gpios[CON_GPIO_NO]);
117 if (con < 0) {
118 debug("%s: Error while reading 'con' GPIO (err = %d)",
119 dev->name, con);
120 return con;
121 }
122
123 priv->variant = con ? VAR_CON : VAR_CPU;
124
125 priv->multichannel = mc4 ? 4 : (mc2 ? 2 : (sc ? 1 : 0));
126
127 return 0;
128 }
129
130 /**
131 * _read_hwversion() - Read the hardware version from the sysinfo.
132 * @dev: The sysinfo device for which to read the hardware version.
133 *
134 * The hardware version read from the sysinfo (from hard-wired GPIOs) is stored
135 * in the private data structure of the driver to be used by other driver
136 * methods.
137 *
138 * Return: 0 if OK, -ve on error.
139 */
_read_hwversion(struct udevice * dev)140 static int _read_hwversion(struct udevice *dev)
141 {
142 struct sysinfo_gazerbeam_priv *priv = dev_get_priv(dev);
143 int res;
144
145 res = gpio_request_list_by_name(dev, "ver-gpios", priv->ver_gpios,
146 ARRAY_SIZE(priv->ver_gpios),
147 GPIOD_IS_IN);
148 if (res < 0) {
149 debug("%s: Error getting GPIO list 'ver-gpios' (err = %d)\n",
150 dev->name, res);
151 return -ENODEV;
152 }
153
154 res = dm_gpio_get_values_as_int(priv->ver_gpios,
155 ARRAY_SIZE(priv->ver_gpios));
156 if (res < 0) {
157 debug("%s: Error reading HW version from expander (err = %d)\n",
158 dev->name, res);
159 return res;
160 }
161
162 priv->hwversion = res;
163
164 res = gpio_free_list(dev, priv->ver_gpios, ARRAY_SIZE(priv->ver_gpios));
165 if (res < 0) {
166 debug("%s: Error freeing HW version GPIO list (err = %d)\n",
167 dev->name, res);
168 return res;
169 }
170
171 return 0;
172 }
173
sysinfo_gazerbeam_detect(struct udevice * dev)174 static int sysinfo_gazerbeam_detect(struct udevice *dev)
175 {
176 int res;
177
178 res = _read_sysinfo_variant_data(dev);
179 if (res) {
180 debug("%s: Error reading multichannel variant (err = %d)\n",
181 dev->name, res);
182 return res;
183 }
184
185 res = _read_hwversion(dev);
186 if (res) {
187 debug("%s: Error reading hardware version (err = %d)\n",
188 dev->name, res);
189 return res;
190 }
191
192 return 0;
193 }
194
sysinfo_gazerbeam_get_int(struct udevice * dev,int id,int * val)195 static int sysinfo_gazerbeam_get_int(struct udevice *dev, int id, int *val)
196 {
197 struct sysinfo_gazerbeam_priv *priv = dev_get_priv(dev);
198
199 switch (id) {
200 case BOARD_MULTICHANNEL:
201 *val = priv->multichannel;
202 break;
203 case BOARD_VARIANT:
204 *val = priv->variant;
205 break;
206 case BOARD_HWVERSION:
207 *val = priv->hwversion;
208 break;
209 default:
210 debug("%s: Integer value %d unknown\n", dev->name, id);
211 return -EINVAL;
212 }
213
214 return 0;
215 }
216
217 static const struct udevice_id sysinfo_gazerbeam_ids[] = {
218 { .compatible = "gdsys,sysinfo-gazerbeam" },
219 { /* sentinel */ }
220 };
221
222 static const struct sysinfo_ops sysinfo_gazerbeam_ops = {
223 .detect = sysinfo_gazerbeam_detect,
224 .get_int = sysinfo_gazerbeam_get_int,
225 };
226
sysinfo_gazerbeam_probe(struct udevice * dev)227 static int sysinfo_gazerbeam_probe(struct udevice *dev)
228 {
229 struct sysinfo_gazerbeam_priv *priv = dev_get_priv(dev);
230 int gpio_num, i;
231
232 gpio_num = gpio_request_list_by_name(dev, "reset-gpios",
233 priv->reset_gpios,
234 ARRAY_SIZE(priv->reset_gpios),
235 GPIOD_IS_OUT);
236
237 if (gpio_num < 0) {
238 debug("%s: Error getting GPIO list 'reset-gpios' (err = %d)\n",
239 dev->name, gpio_num);
240 return gpio_num;
241 }
242
243 /* Set startup-finished GPIOs */
244 for (i = 0; i < ARRAY_SIZE(priv->reset_gpios); i++) {
245 int res = dm_gpio_set_value(&priv->reset_gpios[i], 0);
246
247 if (res) {
248 debug("%s: Error while setting GPIO %d (err = %d)\n",
249 dev->name, i, res);
250 return res;
251 }
252 }
253
254 return 0;
255 }
256
257 U_BOOT_DRIVER(sysinfo_gazerbeam) = {
258 .name = "sysinfo_gazerbeam",
259 .id = UCLASS_SYSINFO,
260 .of_match = sysinfo_gazerbeam_ids,
261 .ops = &sysinfo_gazerbeam_ops,
262 .priv_auto = sizeof(struct sysinfo_gazerbeam_priv),
263 .probe = sysinfo_gazerbeam_probe,
264 };
265