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 #ifdef CONFIG_CMD_GPIO_READ
16 #include <env.h>
17 #endif
18 #include <asm/gpio.h>
19 #include <linux/err.h>
20
name_to_gpio(const char * name)21 __weak int name_to_gpio(const char *name)
22 {
23 return dectoul(name, NULL);
24 }
25
26 enum gpio_cmd {
27 GPIOC_INPUT,
28 GPIOC_SET,
29 GPIOC_CLEAR,
30 GPIOC_TOGGLE,
31 #ifdef CONFIG_CMD_GPIO_READ
32 GPIOC_READ,
33 #endif
34 };
35
36 #if defined(CONFIG_DM_GPIO) && !defined(gpio_status)
37
38 /* A few flags used by show_gpio() */
39 enum {
40 FLAG_SHOW_ALL = 1 << 0,
41 FLAG_SHOW_BANK = 1 << 1,
42 FLAG_SHOW_NEWLINE = 1 << 2,
43 };
44
gpio_get_description(struct udevice * dev,const char * bank_name,int offset,int * flagsp,bool show_all)45 static void gpio_get_description(struct udevice *dev, const char *bank_name,
46 int offset, int *flagsp, bool show_all)
47 {
48 char buf[80];
49 int ret;
50
51 ret = gpio_get_function(dev, offset, NULL);
52 if (ret < 0)
53 goto err;
54 if (!show_all && !(*flagsp & FLAG_SHOW_ALL) && ret == GPIOF_UNUSED)
55 return;
56 if ((*flagsp & FLAG_SHOW_BANK) && bank_name) {
57 if (*flagsp & FLAG_SHOW_NEWLINE) {
58 putc('\n');
59 *flagsp &= ~FLAG_SHOW_NEWLINE;
60 }
61 printf("Bank %s:\n", bank_name);
62 *flagsp &= ~FLAG_SHOW_BANK;
63 }
64
65 ret = gpio_get_status(dev, offset, buf, sizeof(buf));
66 if (ret)
67 goto err;
68
69 printf("%s\n", buf);
70 return;
71 err:
72 printf("Error %d\n", ret);
73 }
74
do_gpio_status(bool all,const char * gpio_name)75 static int do_gpio_status(bool all, const char *gpio_name)
76 {
77 struct udevice *dev;
78 int banklen;
79 int flags;
80 int ret, err = 0;
81
82 flags = 0;
83 if (gpio_name && !*gpio_name)
84 gpio_name = NULL;
85 for (ret = uclass_first_device_check(UCLASS_GPIO, &dev);
86 dev;
87 ret = uclass_next_device_check(&dev)) {
88 const char *bank_name;
89 int num_bits;
90
91 if (ret) {
92 printf("GPIO device %s probe error %i\n",
93 dev->name, ret);
94 err = ret;
95 continue;
96 }
97
98 flags |= FLAG_SHOW_BANK;
99 if (all)
100 flags |= FLAG_SHOW_ALL;
101 bank_name = gpio_get_bank_info(dev, &num_bits);
102 if (!num_bits) {
103 debug("GPIO device %s has no bits\n", dev->name);
104 continue;
105 }
106 banklen = bank_name ? strlen(bank_name) : 0;
107
108 if (!gpio_name || !bank_name ||
109 !strncasecmp(gpio_name, bank_name, banklen)) {
110 const char *p;
111 int offset;
112
113 p = gpio_name + banklen;
114 if (gpio_name && *p) {
115 offset = dectoul(p, NULL);
116 gpio_get_description(dev, bank_name, offset,
117 &flags, true);
118 } else {
119 for (offset = 0; offset < num_bits; offset++) {
120 gpio_get_description(dev, bank_name,
121 offset, &flags, false);
122 }
123 }
124 }
125 /* Add a newline between bank names */
126 if (!(flags & FLAG_SHOW_BANK))
127 flags |= FLAG_SHOW_NEWLINE;
128 }
129
130 return err;
131 }
132 #endif
133
do_gpio(struct cmd_tbl * cmdtp,int flag,int argc,char * const argv[])134 static int do_gpio(struct cmd_tbl *cmdtp, int flag, int argc,
135 char *const argv[])
136 {
137 unsigned int gpio;
138 enum gpio_cmd sub_cmd;
139 int value;
140 const char *str_cmd, *str_gpio = NULL;
141 #ifdef CONFIG_CMD_GPIO_READ
142 const char *str_var = NULL;
143 #endif
144 int ret;
145 #ifdef CONFIG_DM_GPIO
146 bool all = false;
147 #endif
148
149 if (argc < 2)
150 show_usage:
151 return CMD_RET_USAGE;
152 str_cmd = argv[1];
153 argc -= 2;
154 argv += 2;
155 #ifdef CONFIG_DM_GPIO
156 if (argc > 0 && !strncmp(str_cmd, "status", 2) && !strcmp(*argv, "-a")) {
157 all = true;
158 argc--;
159 argv++;
160 }
161 #endif
162 #ifdef CONFIG_CMD_GPIO_READ
163 if (argc > 0 && !strncmp(str_cmd, "read", 2)) {
164 if (argc < 2)
165 goto show_usage;
166 str_var = *argv;
167 argc--;
168 argv++;
169 }
170 #endif
171 if (argc > 0)
172 str_gpio = *argv;
173 if (!strncmp(str_cmd, "status", 2)) {
174 /* Support deprecated gpio_status() */
175 #ifdef gpio_status
176 gpio_status();
177 return 0;
178 #elif defined(CONFIG_DM_GPIO)
179 return cmd_process_error(cmdtp, do_gpio_status(all, str_gpio));
180 #else
181 goto show_usage;
182 #endif
183 }
184
185 if (!str_gpio)
186 goto show_usage;
187
188 /* parse the behavior */
189 switch (*str_cmd) {
190 case 'i':
191 sub_cmd = GPIOC_INPUT;
192 break;
193 case 's':
194 sub_cmd = GPIOC_SET;
195 break;
196 case 'c':
197 sub_cmd = GPIOC_CLEAR;
198 break;
199 case 't':
200 sub_cmd = GPIOC_TOGGLE;
201 break;
202 #ifdef CONFIG_CMD_GPIO_READ
203 case 'r':
204 sub_cmd = GPIOC_READ;
205 break;
206 #endif
207 default:
208 goto show_usage;
209 }
210
211 #if defined(CONFIG_DM_GPIO)
212 /*
213 * TODO(sjg@chromium.org): For now we must fit into the existing GPIO
214 * framework, so we look up the name here and convert it to a GPIO number.
215 * Once all GPIO drivers are converted to driver model, we can change the
216 * code here to use the GPIO uclass interface instead of the numbered
217 * GPIO compatibility layer.
218 */
219 ret = gpio_lookup_name(str_gpio, NULL, NULL, &gpio);
220 if (ret) {
221 printf("GPIO: '%s' not found\n", str_gpio);
222 return cmd_process_error(cmdtp, ret);
223 }
224 #else
225 /* turn the gpio name into a gpio number */
226 gpio = name_to_gpio(str_gpio);
227 if (gpio < 0)
228 goto show_usage;
229 #endif
230 /* grab the pin before we tweak it */
231 ret = gpio_request(gpio, "cmd_gpio");
232 if (ret && ret != -EBUSY) {
233 printf("gpio: requesting pin %u failed\n", gpio);
234 return -1;
235 }
236
237 /* finally, let's do it: set direction and exec command */
238 if (sub_cmd == GPIOC_INPUT
239 #ifdef CONFIG_CMD_GPIO_READ
240 || sub_cmd == GPIOC_READ
241 #endif
242 ) {
243 gpio_direction_input(gpio);
244 value = gpio_get_value(gpio);
245 } else {
246 switch (sub_cmd) {
247 case GPIOC_SET:
248 value = 1;
249 break;
250 case GPIOC_CLEAR:
251 value = 0;
252 break;
253 case GPIOC_TOGGLE:
254 value = gpio_get_value(gpio);
255 if (!IS_ERR_VALUE(value))
256 value = !value;
257 break;
258 default:
259 goto show_usage;
260 }
261 gpio_direction_output(gpio, value);
262 }
263 printf("gpio: pin %s (gpio %u) value is ", str_gpio, gpio);
264
265 if (IS_ERR_VALUE(value)) {
266 printf("unknown (ret=%d)\n", value);
267 goto err;
268 } else {
269 printf("%d\n", value);
270 #ifdef CONFIG_CMD_GPIO_READ
271 if (sub_cmd == GPIOC_READ)
272 env_set_ulong(str_var, (ulong)value);
273 #endif
274 }
275
276 if (sub_cmd != GPIOC_INPUT && !IS_ERR_VALUE(value)
277 #ifdef CONFIG_CMD_GPIO_READ
278 && sub_cmd != GPIOC_READ
279 #endif
280 ) {
281 int nval = gpio_get_value(gpio);
282
283 if (IS_ERR_VALUE(nval)) {
284 printf(" Warning: no access to GPIO output value\n");
285 goto err;
286 } else if (nval != value) {
287 printf(" Warning: value of pin is still %d\n", nval);
288 goto err;
289 }
290 }
291
292 if (ret != -EBUSY)
293 gpio_free(gpio);
294
295 /*
296 * Whilst wrong, the legacy gpio input command returns the pin
297 * value, or CMD_RET_FAILURE (which is indistinguishable from a
298 * valid pin value).
299 */
300 return (sub_cmd == GPIOC_INPUT) ? value : CMD_RET_SUCCESS;
301
302 err:
303 if (ret != -EBUSY)
304 gpio_free(gpio);
305 return CMD_RET_FAILURE;
306 }
307
308 U_BOOT_CMD(gpio, 4, 0, do_gpio,
309 "query and control gpio pins",
310 "<input|set|clear|toggle> <pin>\n"
311 " - input/set/clear/toggle the specified pin\n"
312 #ifdef CONFIG_CMD_GPIO_READ
313 "gpio read <name> <pin>\n"
314 " - set environment variable 'name' to the specified pin\n"
315 #endif
316 "gpio status [-a] [<bank> | <pin>] - show [all/claimed] GPIOs");
317