As explained in commit 4af2a33ee5b9 ("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.
Signed-off-by: Diego Rondini <diego.rond...@kynetics.com>
---
cmd/gpio.c | 24 ++++++++++++++++++++----
test/py/tests/test_gpio.py | 15 +++++++++++++++
2 files changed, 35 insertions(+), 4 deletions(-)
diff --git a/cmd/gpio.c b/cmd/gpio.c
index 4150024e628..150c77cbcf9 100644
--- a/cmd/gpio.c
+++ b/cmd/gpio.c
@@ -12,6 +12,7 @@
#include <dm.h>
#include <log.h>
#include <malloc.h>
+#include <env.h>
#include <asm/gpio.h>
#include <linux/err.h>
@@ -25,6 +26,7 @@ enum gpio_cmd {
GPIOC_SET,
GPIOC_CLEAR,
GPIOC_TOGGLE,
+ GPIOC_READ,
};
#if defined(CONFIG_DM_GPIO) && !defined(gpio_status)
@@ -124,7 +126,7 @@ static int do_gpio(struct cmd_tbl *cmdtp, int flag, int
argc,
unsigned int gpio;
enum gpio_cmd sub_cmd;
int value;
- const char *str_cmd, *str_gpio = NULL;
+ const char *str_cmd, *str_gpio, *str_var = NULL;
int ret;
#ifdef CONFIG_DM_GPIO
bool all = false;
@@ -137,12 +139,19 @@ static int do_gpio(struct cmd_tbl *cmdtp, int flag, int
argc,
argc -= 2;
argv += 2;
#ifdef CONFIG_DM_GPIO
- if (argc > 0 && !strcmp(*argv, "-a")) {
+ if (argc > 0 && !strncmp(str_cmd, "status", 2) && !strcmp(*argv, "-a"))
{
all = true;
argc--;
argv++;
}
#endif
+ if (argc > 0 && !strncmp(str_cmd, "read", 2)) {
+ if (argc < 2)
+ goto show_usage;
+ str_var = *argv;
+ argc--;
+ argv++;
+ }
if (argc > 0)
str_gpio = *argv;
if (!strncmp(str_cmd, "status", 2)) {
@@ -174,6 +183,9 @@ static int do_gpio(struct cmd_tbl *cmdtp, int flag, int
argc,
case 't':
sub_cmd = GPIOC_TOGGLE;
break;
+ case 'r':
+ sub_cmd = GPIOC_READ;
+ break;
default:
goto show_usage;
}
@@ -205,7 +217,7 @@ static int do_gpio(struct cmd_tbl *cmdtp, int flag, int
argc,
}
/* finally, let's do it: set direction and exec command */
- if (sub_cmd == GPIOC_INPUT) {
+ if (sub_cmd == GPIOC_INPUT || sub_cmd == GPIOC_READ) {
gpio_direction_input(gpio);
value = gpio_get_value(gpio);
} else {
@@ -233,9 +245,11 @@ static int do_gpio(struct cmd_tbl *cmdtp, int flag, int
argc,
goto err;
} else {
printf("%d\n", value);
+ if (sub_cmd == GPIOC_READ)
+ env_set_ulong(str_var, (ulong)value);
}
- if (sub_cmd != GPIOC_INPUT && !IS_ERR_VALUE(value)) {
+ if (sub_cmd != GPIOC_INPUT && sub_cmd != GPIOC_READ &&
!IS_ERR_VALUE(value)) {
int nval = gpio_get_value(gpio);
if (IS_ERR_VALUE(nval)) {
@@ -267,4 +281,6 @@ 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 read <name> <pin>\n"
+ " - set environment variable 'name' to the specified pin\n"
"gpio status [-a] [<bank> | <pin>] - show [all/claimed] GPIOs");
diff --git a/test/py/tests/test_gpio.py b/test/py/tests/test_gpio.py
index 8c64f686b0b..52bc8502d3e 100644
--- a/test/py/tests/test_gpio.py
+++ b/test/py/tests/test_gpio.py
@@ -35,3 +35,18 @@ def test_gpio_exit_statuses(u_boot_console):
assert(expected_response in response)
response = u_boot_console.run_command('gpio input 200; echo rc:$?')
assert(expected_response in response)
+
+@pytest.mark.boardspec('sandbox')
+@pytest.mark.buildconfigspec('cmd_gpio')
+def test_gpio_read(u_boot_console):
+ """Test that gpio read correctly sets the variable to the value of a gpio
pin."""
+
+ response = u_boot_console.run_command('gpio read var 0; echo val:$var')
+ expected_response = 'val:0'
+ assert(expected_response in response)
+ response = u_boot_console.run_command('gpio toggle 0; gpio read var 0;
echo val:$var')
+ expected_response = 'val:1'
+ assert(expected_response in response)
+ response = u_boot_console.run_command('setenv var; gpio read var
nonexistent-gpio; echo val:$var')
+ expected_response = 'val:'
+ assert(expected_response in response)
--
2.34.1
