cmd/gpio.c

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