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dd2b8c1155
As explained in commit 4af2a33ee5 ("cmd: gpio: Make `gpio input`
return pin value again") the `gpio input` is used in scripts to obtain
the value of a pin, despite the fact that CMD_RET_FAILURE is
indistinguishable from a valid pin value.
To be able to detect failures and properly use the value of a GPIO in
scripts we introduce the `gpio read` command that sets the variable
`name` to the value of the pin. Return code of the `gpio read` command
can be used to check for CMD_RET_SUCCESS or CMD_RET_FAILURE.
CONFIG_CMD_GPIO_READ is used to enable the `gpio read` command.
Signed-off-by: Diego Rondini <diego.rondini@kynetics.com>
309 lines
6.4 KiB
C
309 lines
6.4 KiB
C
/*
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* Control GPIO pins on the fly
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*
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* Copyright (c) 2008-2011 Analog Devices Inc.
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*
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* Licensed under the GPL-2 or later.
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*/
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#include <common.h>
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#include <command.h>
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#include <errno.h>
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#include <dm.h>
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#include <log.h>
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#include <malloc.h>
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#ifdef CONFIG_CMD_GPIO_READ
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#include <env.h>
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#endif
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#include <asm/gpio.h>
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#include <linux/err.h>
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__weak int name_to_gpio(const char *name)
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{
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return dectoul(name, NULL);
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}
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enum gpio_cmd {
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GPIOC_INPUT,
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GPIOC_SET,
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GPIOC_CLEAR,
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GPIOC_TOGGLE,
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#ifdef CONFIG_CMD_GPIO_READ
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GPIOC_READ,
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#endif
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};
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#if defined(CONFIG_DM_GPIO) && !defined(gpio_status)
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/* A few flags used by show_gpio() */
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enum {
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FLAG_SHOW_ALL = 1 << 0,
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FLAG_SHOW_BANK = 1 << 1,
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FLAG_SHOW_NEWLINE = 1 << 2,
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};
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static void gpio_get_description(struct udevice *dev, const char *bank_name,
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int offset, int *flagsp, bool show_all)
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{
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char buf[80];
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int ret;
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ret = gpio_get_function(dev, offset, NULL);
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if (ret < 0)
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goto err;
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if (!show_all && !(*flagsp & FLAG_SHOW_ALL) && ret == GPIOF_UNUSED)
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return;
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if ((*flagsp & FLAG_SHOW_BANK) && bank_name) {
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if (*flagsp & FLAG_SHOW_NEWLINE) {
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putc('\n');
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*flagsp &= ~FLAG_SHOW_NEWLINE;
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}
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printf("Bank %s:\n", bank_name);
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*flagsp &= ~FLAG_SHOW_BANK;
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}
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ret = gpio_get_status(dev, offset, buf, sizeof(buf));
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if (ret)
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goto err;
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printf("%s\n", buf);
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return;
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err:
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printf("Error %d\n", ret);
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}
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static int do_gpio_status(bool all, const char *gpio_name)
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{
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struct udevice *dev;
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int banklen;
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int flags;
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int ret;
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flags = 0;
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if (gpio_name && !*gpio_name)
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gpio_name = NULL;
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for (ret = uclass_first_device(UCLASS_GPIO, &dev);
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dev;
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ret = uclass_next_device(&dev)) {
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const char *bank_name;
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int num_bits;
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flags |= FLAG_SHOW_BANK;
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if (all)
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flags |= FLAG_SHOW_ALL;
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bank_name = gpio_get_bank_info(dev, &num_bits);
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if (!num_bits) {
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debug("GPIO device %s has no bits\n", dev->name);
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continue;
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}
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banklen = bank_name ? strlen(bank_name) : 0;
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if (!gpio_name || !bank_name ||
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!strncasecmp(gpio_name, bank_name, banklen)) {
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const char *p;
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int offset;
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p = gpio_name + banklen;
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if (gpio_name && *p) {
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offset = dectoul(p, NULL);
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gpio_get_description(dev, bank_name, offset,
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&flags, true);
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} else {
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for (offset = 0; offset < num_bits; offset++) {
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gpio_get_description(dev, bank_name,
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offset, &flags, false);
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}
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}
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}
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/* Add a newline between bank names */
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if (!(flags & FLAG_SHOW_BANK))
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flags |= FLAG_SHOW_NEWLINE;
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}
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return ret;
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}
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#endif
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static int do_gpio(struct cmd_tbl *cmdtp, int flag, int argc,
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char *const argv[])
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{
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unsigned int gpio;
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enum gpio_cmd sub_cmd;
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int value;
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const char *str_cmd, *str_gpio = NULL;
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#ifdef CONFIG_CMD_GPIO_READ
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const char *str_var = NULL;
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#endif
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int ret;
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#ifdef CONFIG_DM_GPIO
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bool all = false;
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#endif
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if (argc < 2)
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show_usage:
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return CMD_RET_USAGE;
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str_cmd = argv[1];
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argc -= 2;
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argv += 2;
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#ifdef CONFIG_DM_GPIO
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if (argc > 0 && !strncmp(str_cmd, "status", 2) && !strcmp(*argv, "-a")) {
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all = true;
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argc--;
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argv++;
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}
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#endif
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#ifdef CONFIG_CMD_GPIO_READ
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if (argc > 0 && !strncmp(str_cmd, "read", 2)) {
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if (argc < 2)
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goto show_usage;
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str_var = *argv;
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argc--;
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argv++;
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}
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#endif
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if (argc > 0)
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str_gpio = *argv;
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if (!strncmp(str_cmd, "status", 2)) {
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/* Support deprecated gpio_status() */
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#ifdef gpio_status
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gpio_status();
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return 0;
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#elif defined(CONFIG_DM_GPIO)
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return cmd_process_error(cmdtp, do_gpio_status(all, str_gpio));
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#else
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goto show_usage;
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#endif
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}
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if (!str_gpio)
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goto show_usage;
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/* parse the behavior */
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switch (*str_cmd) {
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case 'i':
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sub_cmd = GPIOC_INPUT;
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break;
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case 's':
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sub_cmd = GPIOC_SET;
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break;
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case 'c':
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sub_cmd = GPIOC_CLEAR;
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break;
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case 't':
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sub_cmd = GPIOC_TOGGLE;
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break;
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#ifdef CONFIG_CMD_GPIO_READ
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case 'r':
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sub_cmd = GPIOC_READ;
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break;
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#endif
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default:
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goto show_usage;
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}
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#if defined(CONFIG_DM_GPIO)
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/*
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* TODO(sjg@chromium.org): For now we must fit into the existing GPIO
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* framework, so we look up the name here and convert it to a GPIO number.
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* Once all GPIO drivers are converted to driver model, we can change the
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* code here to use the GPIO uclass interface instead of the numbered
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* GPIO compatibility layer.
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*/
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ret = gpio_lookup_name(str_gpio, NULL, NULL, &gpio);
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if (ret) {
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printf("GPIO: '%s' not found\n", str_gpio);
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return cmd_process_error(cmdtp, ret);
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}
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#else
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/* turn the gpio name into a gpio number */
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gpio = name_to_gpio(str_gpio);
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if (gpio < 0)
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goto show_usage;
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#endif
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/* grab the pin before we tweak it */
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ret = gpio_request(gpio, "cmd_gpio");
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if (ret && ret != -EBUSY) {
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printf("gpio: requesting pin %u failed\n", gpio);
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return -1;
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}
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/* finally, let's do it: set direction and exec command */
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if (sub_cmd == GPIOC_INPUT
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#ifdef CONFIG_CMD_GPIO_READ
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|| sub_cmd == GPIOC_READ
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#endif
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) {
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gpio_direction_input(gpio);
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value = gpio_get_value(gpio);
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} else {
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switch (sub_cmd) {
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case GPIOC_SET:
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value = 1;
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break;
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case GPIOC_CLEAR:
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value = 0;
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break;
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case GPIOC_TOGGLE:
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value = gpio_get_value(gpio);
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if (!IS_ERR_VALUE(value))
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value = !value;
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break;
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default:
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goto show_usage;
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}
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gpio_direction_output(gpio, value);
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}
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printf("gpio: pin %s (gpio %u) value is ", str_gpio, gpio);
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if (IS_ERR_VALUE(value)) {
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printf("unknown (ret=%d)\n", value);
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goto err;
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} else {
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printf("%d\n", value);
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#ifdef CONFIG_CMD_GPIO_READ
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if (sub_cmd == GPIOC_READ)
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env_set_ulong(str_var, (ulong)value);
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#endif
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}
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if (sub_cmd != GPIOC_INPUT && !IS_ERR_VALUE(value)
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#ifdef CONFIG_CMD_GPIO_READ
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&& sub_cmd != GPIOC_READ
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#endif
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) {
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int nval = gpio_get_value(gpio);
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if (IS_ERR_VALUE(nval)) {
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printf(" Warning: no access to GPIO output value\n");
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goto err;
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} else if (nval != value) {
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printf(" Warning: value of pin is still %d\n", nval);
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goto err;
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}
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}
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if (ret != -EBUSY)
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gpio_free(gpio);
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/*
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* Whilst wrong, the legacy gpio input command returns the pin
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* value, or CMD_RET_FAILURE (which is indistinguishable from a
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* valid pin value).
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*/
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return (sub_cmd == GPIOC_INPUT) ? value : CMD_RET_SUCCESS;
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err:
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if (ret != -EBUSY)
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gpio_free(gpio);
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return CMD_RET_FAILURE;
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}
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U_BOOT_CMD(gpio, 4, 0, do_gpio,
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"query and control gpio pins",
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"<input|set|clear|toggle> <pin>\n"
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" - input/set/clear/toggle the specified pin\n"
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#ifdef CONFIG_CMD_GPIO_READ
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"gpio read <name> <pin>\n"
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" - set environment variable 'name' to the specified pin\n"
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#endif
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"gpio status [-a] [<bank> | <pin>] - show [all/claimed] GPIOs");
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