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 <common.h>
8 #include <dm.h>
9 #include <board.h>
10 #include <i2c.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 board_gazerbeam_priv - Private data structure for the gazerbeam board
30 * driver.
31 * @reset_gpios: GPIOs for the board's reset GPIOs.
32 * @var_gpios: GPIOs for the board's hardware variant GPIOs
33 * @ver_gpios: GPIOs for the board's hardware version GPIOs
34 * @variant: Container for the board's hardware variant (CON/CPU)
35 * @multichannel: Container for the board's multichannel variant (MC4/MC2/SC)
36 * @hwversion: Container for the board's hardware version
37 */
38 struct board_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_board_variant_data() - Read variant information from the hardware.
49 * @dev: The board device for which to determine the multichannel and device
50 * type information.
51 *
52 * The data read from the board'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_board_variant_data(struct udevice * dev)58 static int _read_board_variant_data(struct udevice *dev)
59 {
60 struct board_gazerbeam_priv *priv = dev_get_priv(dev);
61 struct udevice *i2c_bus;
62 struct udevice *dummy;
63 char *listname;
64 int mc4, 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 = !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 && mc4) {
85 debug("%s: Board hardware configuration inconsistent.\n",
86 dev->name);
87 return -EINVAL;
88 }
89
90 listname = mc2 ? "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 con = dm_gpio_get_value(&priv->var_gpios[CON_GPIO_NO]);
109 if (con < 0) {
110 debug("%s: Error while reading 'con' GPIO (err = %d)",
111 dev->name, con);
112 return con;
113 }
114
115 if ((sc && mc2) || (sc && mc4) || (!sc && !mc2 && !mc4)) {
116 debug("%s: Board hardware configuration inconsistent.\n",
117 dev->name);
118 return -EINVAL;
119 }
120
121 priv->variant = con ? VAR_CON : VAR_CPU;
122
123 priv->multichannel = mc4 ? 4 : (mc2 ? 2 : (sc ? 1 : 0));
124
125 return 0;
126 }
127
128 /**
129 * _read_hwversion() - Read the hardware version from the board.
130 * @dev: The board device for which to read the hardware version.
131 *
132 * The hardware version read from the board (from hard-wired GPIOs) is stored
133 * in the private data structure of the driver to be used by other driver
134 * methods.
135 *
136 * Return: 0 if OK, -ve on error.
137 */
_read_hwversion(struct udevice * dev)138 static int _read_hwversion(struct udevice *dev)
139 {
140 struct board_gazerbeam_priv *priv = dev_get_priv(dev);
141 int res;
142
143 res = gpio_request_list_by_name(dev, "ver-gpios", priv->ver_gpios,
144 ARRAY_SIZE(priv->ver_gpios),
145 GPIOD_IS_IN);
146 if (res < 0) {
147 debug("%s: Error getting GPIO list 'ver-gpios' (err = %d)\n",
148 dev->name, res);
149 return -ENODEV;
150 }
151
152 res = dm_gpio_get_values_as_int(priv->ver_gpios,
153 ARRAY_SIZE(priv->ver_gpios));
154 if (res < 0) {
155 debug("%s: Error reading HW version from expander (err = %d)\n",
156 dev->name, res);
157 return res;
158 }
159
160 priv->hwversion = res;
161
162 res = gpio_free_list(dev, priv->ver_gpios, ARRAY_SIZE(priv->ver_gpios));
163 if (res < 0) {
164 debug("%s: Error freeing HW version GPIO list (err = %d)\n",
165 dev->name, res);
166 return res;
167 }
168
169 return 0;
170 }
171
board_gazerbeam_detect(struct udevice * dev)172 static int board_gazerbeam_detect(struct udevice *dev)
173 {
174 int res;
175
176 res = _read_board_variant_data(dev);
177 if (res) {
178 debug("%s: Error reading multichannel variant (err = %d)\n",
179 dev->name, res);
180 return res;
181 }
182
183 res = _read_hwversion(dev);
184 if (res) {
185 debug("%s: Error reading hardware version (err = %d)\n",
186 dev->name, res);
187 return res;
188 }
189
190 return 0;
191 }
192
board_gazerbeam_get_int(struct udevice * dev,int id,int * val)193 static int board_gazerbeam_get_int(struct udevice *dev, int id, int *val)
194 {
195 struct board_gazerbeam_priv *priv = dev_get_priv(dev);
196
197 switch (id) {
198 case BOARD_MULTICHANNEL:
199 *val = priv->multichannel;
200 break;
201 case BOARD_VARIANT:
202 *val = priv->variant;
203 break;
204 case BOARD_HWVERSION:
205 *val = priv->hwversion;
206 break;
207 default:
208 debug("%s: Integer value %d unknown\n", dev->name, id);
209 return -EINVAL;
210 }
211
212 return 0;
213 }
214
215 static const struct udevice_id board_gazerbeam_ids[] = {
216 { .compatible = "gdsys,board_gazerbeam" },
217 { /* sentinel */ }
218 };
219
220 static const struct board_ops board_gazerbeam_ops = {
221 .detect = board_gazerbeam_detect,
222 .get_int = board_gazerbeam_get_int,
223 };
224
board_gazerbeam_probe(struct udevice * dev)225 static int board_gazerbeam_probe(struct udevice *dev)
226 {
227 struct board_gazerbeam_priv *priv = dev_get_priv(dev);
228 int gpio_num, i;
229
230 gpio_num = gpio_request_list_by_name(dev, "reset-gpios",
231 priv->reset_gpios,
232 ARRAY_SIZE(priv->reset_gpios),
233 GPIOD_IS_OUT);
234
235 if (gpio_num < 0) {
236 debug("%s: Error getting GPIO list 'reset-gpios' (err = %d)\n",
237 dev->name, gpio_num);
238 return gpio_num;
239 }
240
241 /* Set startup-finished GPIOs */
242 for (i = 0; i < ARRAY_SIZE(priv->reset_gpios); i++) {
243 int res = dm_gpio_set_value(&priv->reset_gpios[i], 0);
244
245 if (res) {
246 debug("%s: Error while setting GPIO %d (err = %d)\n",
247 dev->name, i, res);
248 return res;
249 }
250 }
251
252 return 0;
253 }
254
255 U_BOOT_DRIVER(board_gazerbeam) = {
256 .name = "board_gazerbeam",
257 .id = UCLASS_BOARD,
258 .of_match = board_gazerbeam_ids,
259 .ops = &board_gazerbeam_ops,
260 .priv_auto_alloc_size = sizeof(struct board_gazerbeam_priv),
261 .probe = board_gazerbeam_probe,
262 };
263