1 /*
2 * Control GPIO pins on the fly
3 *
4 * Copyright (c) 2008-2011 Analog Devices Inc.
5 *
6 * Licensed under the GPL-2 or later.
7 */
8
9 #include <common.h>
10 #include <command.h>
11 #include <errno.h>
12 #include <dm.h>
13 #include <log.h>
14 #include <malloc.h>
15 #include <asm/gpio.h>
16 #include <linux/err.h>
17
name_to_gpio(const char * name)18 __weak int name_to_gpio(const char *name)
19 {
20 return simple_strtoul(name, NULL, 10);
21 }
22
23 enum gpio_cmd {
24 GPIOC_INPUT,
25 GPIOC_SET,
26 GPIOC_CLEAR,
27 GPIOC_TOGGLE,
28 };
29
30 #if defined(CONFIG_DM_GPIO) && !defined(gpio_status)
31
32 /* A few flags used by show_gpio() */
33 enum {
34 FLAG_SHOW_ALL = 1 << 0,
35 FLAG_SHOW_BANK = 1 << 1,
36 FLAG_SHOW_NEWLINE = 1 << 2,
37 };
38
gpio_get_description(struct udevice * dev,const char * bank_name,int offset,int * flagsp,bool show_all)39 static void gpio_get_description(struct udevice *dev, const char *bank_name,
40 int offset, int *flagsp, bool show_all)
41 {
42 char buf[80];
43 int ret;
44
45 ret = gpio_get_function(dev, offset, NULL);
46 if (ret < 0)
47 goto err;
48 if (!show_all && !(*flagsp & FLAG_SHOW_ALL) && ret == GPIOF_UNUSED)
49 return;
50 if ((*flagsp & FLAG_SHOW_BANK) && bank_name) {
51 if (*flagsp & FLAG_SHOW_NEWLINE) {
52 putc('\n');
53 *flagsp &= ~FLAG_SHOW_NEWLINE;
54 }
55 printf("Bank %s:\n", bank_name);
56 *flagsp &= ~FLAG_SHOW_BANK;
57 }
58
59 ret = gpio_get_status(dev, offset, buf, sizeof(buf));
60 if (ret)
61 goto err;
62
63 printf("%s\n", buf);
64 return;
65 err:
66 printf("Error %d\n", ret);
67 }
68
do_gpio_status(bool all,const char * gpio_name)69 static int do_gpio_status(bool all, const char *gpio_name)
70 {
71 struct udevice *dev;
72 int banklen;
73 int flags;
74 int ret;
75
76 flags = 0;
77 if (gpio_name && !*gpio_name)
78 gpio_name = NULL;
79 for (ret = uclass_first_device(UCLASS_GPIO, &dev);
80 dev;
81 ret = uclass_next_device(&dev)) {
82 const char *bank_name;
83 int num_bits;
84
85 flags |= FLAG_SHOW_BANK;
86 if (all)
87 flags |= FLAG_SHOW_ALL;
88 bank_name = gpio_get_bank_info(dev, &num_bits);
89 if (!num_bits) {
90 debug("GPIO device %s has no bits\n", dev->name);
91 continue;
92 }
93 banklen = bank_name ? strlen(bank_name) : 0;
94
95 if (!gpio_name || !bank_name ||
96 !strncasecmp(gpio_name, bank_name, banklen)) {
97 const char *p;
98 int offset;
99
100 p = gpio_name + banklen;
101 if (gpio_name && *p) {
102 offset = simple_strtoul(p, NULL, 10);
103 gpio_get_description(dev, bank_name, offset,
104 &flags, true);
105 } else {
106 for (offset = 0; offset < num_bits; offset++) {
107 gpio_get_description(dev, bank_name,
108 offset, &flags, false);
109 }
110 }
111 }
112 /* Add a newline between bank names */
113 if (!(flags & FLAG_SHOW_BANK))
114 flags |= FLAG_SHOW_NEWLINE;
115 }
116
117 return ret;
118 }
119 #endif
120
do_gpio(struct cmd_tbl * cmdtp,int flag,int argc,char * const argv[])121 static int do_gpio(struct cmd_tbl *cmdtp, int flag, int argc,
122 char *const argv[])
123 {
124 unsigned int gpio;
125 enum gpio_cmd sub_cmd;
126 int value;
127 const char *str_cmd, *str_gpio = NULL;
128 int ret;
129 #ifdef CONFIG_DM_GPIO
130 bool all = false;
131 #endif
132
133 if (argc < 2)
134 show_usage:
135 return CMD_RET_USAGE;
136 str_cmd = argv[1];
137 argc -= 2;
138 argv += 2;
139 #ifdef CONFIG_DM_GPIO
140 if (argc > 0 && !strcmp(*argv, "-a")) {
141 all = true;
142 argc--;
143 argv++;
144 }
145 #endif
146 if (argc > 0)
147 str_gpio = *argv;
148 if (!strncmp(str_cmd, "status", 2)) {
149 /* Support deprecated gpio_status() */
150 #ifdef gpio_status
151 gpio_status();
152 return 0;
153 #elif defined(CONFIG_DM_GPIO)
154 return cmd_process_error(cmdtp, do_gpio_status(all, str_gpio));
155 #else
156 goto show_usage;
157 #endif
158 }
159
160 if (!str_gpio)
161 goto show_usage;
162
163 /* parse the behavior */
164 switch (*str_cmd) {
165 case 'i':
166 sub_cmd = GPIOC_INPUT;
167 break;
168 case 's':
169 sub_cmd = GPIOC_SET;
170 break;
171 case 'c':
172 sub_cmd = GPIOC_CLEAR;
173 break;
174 case 't':
175 sub_cmd = GPIOC_TOGGLE;
176 break;
177 default:
178 goto show_usage;
179 }
180
181 #if defined(CONFIG_DM_GPIO)
182 /*
183 * TODO(sjg@chromium.org): For now we must fit into the existing GPIO
184 * framework, so we look up the name here and convert it to a GPIO number.
185 * Once all GPIO drivers are converted to driver model, we can change the
186 * code here to use the GPIO uclass interface instead of the numbered
187 * GPIO compatibility layer.
188 */
189 ret = gpio_lookup_name(str_gpio, NULL, NULL, &gpio);
190 if (ret) {
191 printf("GPIO: '%s' not found\n", str_gpio);
192 return cmd_process_error(cmdtp, ret);
193 }
194 #else
195 /* turn the gpio name into a gpio number */
196 gpio = name_to_gpio(str_gpio);
197 if (gpio < 0)
198 goto show_usage;
199 #endif
200 /* grab the pin before we tweak it */
201 ret = gpio_request(gpio, "cmd_gpio");
202 if (ret && ret != -EBUSY) {
203 printf("gpio: requesting pin %u failed\n", gpio);
204 return -1;
205 }
206
207 /* finally, let's do it: set direction and exec command */
208 if (sub_cmd == GPIOC_INPUT) {
209 gpio_direction_input(gpio);
210 value = gpio_get_value(gpio);
211 } else {
212 switch (sub_cmd) {
213 case GPIOC_SET:
214 value = 1;
215 break;
216 case GPIOC_CLEAR:
217 value = 0;
218 break;
219 case GPIOC_TOGGLE:
220 value = gpio_get_value(gpio);
221 if (!IS_ERR_VALUE(value))
222 value = !value;
223 break;
224 default:
225 goto show_usage;
226 }
227 gpio_direction_output(gpio, value);
228 }
229 printf("gpio: pin %s (gpio %u) value is ", str_gpio, gpio);
230
231 if (IS_ERR_VALUE(value)) {
232 printf("unknown (ret=%d)\n", value);
233 goto err;
234 } else {
235 printf("%d\n", value);
236 }
237
238 if (sub_cmd != GPIOC_INPUT && !IS_ERR_VALUE(value)) {
239 int nval = gpio_get_value(gpio);
240
241 if (IS_ERR_VALUE(nval)) {
242 printf(" Warning: no access to GPIO output value\n");
243 goto err;
244 } else if (nval != value) {
245 printf(" Warning: value of pin is still %d\n", nval);
246 goto err;
247 }
248 }
249
250 if (ret != -EBUSY)
251 gpio_free(gpio);
252
253 /*
254 * Whilst wrong, the legacy gpio input command returns the pin
255 * value, or CMD_RET_FAILURE (which is indistinguishable from a
256 * valid pin value).
257 */
258 return (sub_cmd == GPIOC_INPUT) ? value : CMD_RET_SUCCESS;
259
260 err:
261 if (ret != -EBUSY)
262 gpio_free(gpio);
263 return CMD_RET_FAILURE;
264 }
265
266 U_BOOT_CMD(gpio, 4, 0, do_gpio,
267 "query and control gpio pins",
268 "<input|set|clear|toggle> <pin>\n"
269 " - input/set/clear/toggle the specified pin\n"
270 "gpio status [-a] [<bank> | <pin>] - show [all/claimed] GPIOs");
271