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.rondini@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)