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 #include <asm/gpio.h>
  16 #include <linux/err.h>
  17
  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
  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
  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
 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");