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