u-boot/common/cmd_gpio.c
Simon Glass 9165e8428d dm: gpio: Allow gpio command to adjust GPIOs that are busy
The gpio command mostly relies on gpio_request() and gpio_free() being
nops, in that you can request a GPIO twice. With driver model this is
now implemented correctly, so it fails.

Change the command to deal with a failure to claim the GPIO.

Signed-off-by: Simon Glass <sjg@chromium.org>
2014-08-31 23:21:19 -06:00

234 lines
5.1 KiB
C

/*
* Control GPIO pins on the fly
*
* Copyright (c) 2008-2011 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*/
#include <common.h>
#include <command.h>
#include <errno.h>
#include <dm.h>
#include <asm/gpio.h>
int __weak name_to_gpio(const char *name)
{
return simple_strtoul(name, NULL, 10);
}
enum gpio_cmd {
GPIO_INPUT,
GPIO_SET,
GPIO_CLEAR,
GPIO_TOGGLE,
};
#if defined(CONFIG_DM_GPIO) && !defined(gpio_status)
static const char * const gpio_function[GPIOF_COUNT] = {
"input",
"output",
"unused",
"unknown",
"func",
};
/* A few flags used by show_gpio() */
enum {
FLAG_SHOW_ALL = 1 << 0,
FLAG_SHOW_BANK = 1 << 1,
FLAG_SHOW_NEWLINE = 1 << 2,
};
static void show_gpio(struct udevice *dev, const char *bank_name, int offset,
int *flagsp)
{
struct dm_gpio_ops *ops = gpio_get_ops(dev);
int func = GPIOF_UNKNOWN;
char buf[80];
int ret;
BUILD_BUG_ON(GPIOF_COUNT != ARRAY_SIZE(gpio_function));
if (ops->get_function) {
ret = ops->get_function(dev, offset);
if (ret >= 0 && ret < ARRAY_SIZE(gpio_function))
func = ret;
}
if (!(*flagsp & FLAG_SHOW_ALL) && func == GPIOF_UNUSED)
return;
if ((*flagsp & FLAG_SHOW_BANK) && bank_name) {
if (*flagsp & FLAG_SHOW_NEWLINE) {
putc('\n');
*flagsp &= ~FLAG_SHOW_NEWLINE;
}
printf("Bank %s:\n", bank_name);
*flagsp &= ~FLAG_SHOW_BANK;
}
*buf = '\0';
if (ops->get_state) {
ret = ops->get_state(dev, offset, buf, sizeof(buf));
if (ret) {
puts("<unknown>");
return;
}
} else {
sprintf(buf, "%s%u: %8s %d", bank_name, offset,
gpio_function[func], ops->get_value(dev, offset));
}
puts(buf);
puts("\n");
}
static int do_gpio_status(bool all, const char *gpio_name)
{
struct udevice *dev;
int banklen;
int flags;
int ret;
flags = 0;
if (gpio_name && !*gpio_name)
gpio_name = NULL;
for (ret = uclass_first_device(UCLASS_GPIO, &dev);
dev;
ret = uclass_next_device(&dev)) {
const char *bank_name;
int num_bits;
flags |= FLAG_SHOW_BANK;
if (all)
flags |= FLAG_SHOW_ALL;
bank_name = gpio_get_bank_info(dev, &num_bits);
if (!num_bits)
continue;
banklen = bank_name ? strlen(bank_name) : 0;
if (!gpio_name || !bank_name ||
!strncmp(gpio_name, bank_name, banklen)) {
const char *p = NULL;
int offset;
p = gpio_name + banklen;
if (gpio_name && *p) {
offset = simple_strtoul(p, NULL, 10);
show_gpio(dev, bank_name, offset, &flags);
} else {
for (offset = 0; offset < num_bits; offset++) {
show_gpio(dev, bank_name, offset,
&flags);
}
}
}
/* Add a newline between bank names */
if (!(flags & FLAG_SHOW_BANK))
flags |= FLAG_SHOW_NEWLINE;
}
return ret;
}
#endif
static int do_gpio(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
unsigned int gpio;
enum gpio_cmd sub_cmd;
ulong value;
const char *str_cmd, *str_gpio = NULL;
int ret;
#ifdef CONFIG_DM_GPIO
bool all = false;
#endif
if (argc < 2)
show_usage:
return CMD_RET_USAGE;
str_cmd = argv[1];
argc -= 2;
argv += 2;
#ifdef CONFIG_DM_GPIO
if (argc > 0 && !strcmp(*argv, "-a")) {
all = true;
argc--;
argv++;
}
#endif
if (argc > 0)
str_gpio = *argv;
if (!strcmp(str_cmd, "status")) {
/* Support deprecated gpio_status() */
#ifdef gpio_status
gpio_status();
return 0;
#elif defined(CONFIG_DM_GPIO)
return cmd_process_error(cmdtp, do_gpio_status(all, str_gpio));
#else
goto show_usage;
#endif
}
if (!str_gpio)
goto show_usage;
/* parse the behavior */
switch (*str_cmd) {
case 'i': sub_cmd = GPIO_INPUT; break;
case 's': sub_cmd = GPIO_SET; break;
case 'c': sub_cmd = GPIO_CLEAR; break;
case 't': sub_cmd = GPIO_TOGGLE; break;
default: goto show_usage;
}
#if defined(CONFIG_DM_GPIO)
/*
* TODO(sjg@chromium.org): For now we must fit into the existing GPIO
* framework, so we look up the name here and convert it to a GPIO number.
* Once all GPIO drivers are converted to driver model, we can change the
* code here to use the GPIO uclass interface instead of the numbered
* GPIO compatibility layer.
*/
ret = gpio_lookup_name(str_gpio, NULL, NULL, &gpio);
if (ret)
return cmd_process_error(cmdtp, ret);
#else
/* turn the gpio name into a gpio number */
gpio = name_to_gpio(str_gpio);
if (gpio < 0)
goto show_usage;
#endif
/* grab the pin before we tweak it */
ret = gpio_request(gpio, "cmd_gpio");
if (ret && ret != -EBUSY) {
printf("gpio: requesting pin %u failed\n", gpio);
return -1;
}
/* finally, let's do it: set direction and exec command */
if (sub_cmd == GPIO_INPUT) {
gpio_direction_input(gpio);
value = gpio_get_value(gpio);
} else {
switch (sub_cmd) {
case GPIO_SET: value = 1; break;
case GPIO_CLEAR: value = 0; break;
case GPIO_TOGGLE: value = !gpio_get_value(gpio); break;
default: goto show_usage;
}
gpio_direction_output(gpio, value);
}
printf("gpio: pin %s (gpio %i) value is %lu\n",
str_gpio, gpio, value);
if (ret != -EBUSY)
gpio_free(gpio);
return value;
}
U_BOOT_CMD(gpio, 4, 0, do_gpio,
"query and control gpio pins",
"<input|set|clear|toggle> <pin>\n"
" - input/set/clear/toggle the specified pin\n"
"gpio status [-a] [<bank> | <pin>] - show [all/claimed] GPIOs");