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
  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
  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
  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
 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");