[U-Boot] [PATCH 1/1] at91: Add command to control up to 3 GPIO LEDs from the console

[Stefan Roese]

Hi Daniel,

On Wednesday 06 May 2009, Daniel Gorsulowski wrote:
> This patch allows any at91 board, implementing the GPIO LED API,
> to control the LEDs from the console.
>
> led [ 1 | 2 | 3 | all ]  [ on | off ]

Why limit this to a max of 3 LED's? If this is a generic command (which I like 
btw) then we should support a user/board defined number of LED's. In your case 
it's 3, but the infrastructure should support any number.

More comments below.

<snip>

> diff --git a/common/cmd_led.c b/common/cmd_led.c
> new file mode 100644
> index 0000000..f914d2d
> --- /dev/null
> +++ b/common/cmd_led.c
> @@ -0,0 +1,86 @@
> +/*
> + * (C) Copyright 2008
> + * Ulf Samuelsson <ulf.samuelsson at atmel.com>
> + *
> + * (C) Copyright 2009
> + * Daniel Gorsulowski <daniel.gorsulowski at esd.eu>
> + * esd electronic system design gmbh <www.esd.eu>
> + *
> + * See file CREDITS for list of people who contributed to this
> + * project.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation; either version 2 of
> + * the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
> + * MA 02111-1307 USA
> + */
> +
> +#include <common.h>
> +#include <config.h>
> +#include <command.h>
> +#include <asm/arch/led.h>
> +
> +int do_led(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
> +{
> +	int led;
> +
> +	/* Validate arguments */
> +	if ((argc != 3)) {
> +		printf("Usage:\n%s\n", cmdtp->usage);
> +		return 1;
> +	}
> +	if (strcmp(argv[1], "1") == 0) {
> +		led = (1 << 0);
> +	} else if (strcmp(argv[1], "2") == 0) {
> +		led = (1 << 1);
> +	} else if (strcmp(argv[1], "3") == 0) {
> +		led = (1 << 2);
> +	} else if (strcmp(argv[1], "all") == 0) {
> +		led = 31;
> +	} else {
> +		printf ("Usage:\n%s\n", cmdtp->usage);
> +		return 1;
> +	}

Here we have the problem with max of 3 again. Why not just scan the 2nd 
parameter as an int and use it as parameter for the following function calls 
(see below)?

> +
> +	if (strcmp(argv[2], "off") == 0) {
> +#ifdef CONFIG_USER1_LED
> +		if(led & 1) user1_led_off();
> +#endif
> +#ifdef CONFIG_USER2_LED
> +		if(led & 2) user2_led_off();
> +#endif
> +#ifdef CONFIG_USER3_LED
> +		if(led & 4) user3_led_off();
> +#endif
> +	} else if (strcmp(argv[2], "on") == 0) {
> +#ifdef CONFIG_USER1_LED
> +		if(led & 1) user1_led_on();
> +#endif
> +#ifdef CONFIG_USER2_LED
> +		if(led & 2) user2_led_on();
> +#endif
> +#ifdef CONFIG_USER3_LED
> +		if(led & 4) user3_led_on();
> +#endif

I suggest to use something like this here:

	led_nr = simple_strtoul(argv[1], NULL, 10);
	if (led_nr > CONFIG_LED_MAX) {
		printf ("Usage:\n%s\n", cmdtp->usage);
		return 1;
	}

	if (strcmp(argv[2], "off") == 0) {
		on = 1;
	} else if (strcmp(argv[2], "on") == 0) {
		on = 0;
	} else {
		printf ("Usage:\n%s\n", cmdtp->usage);
		return 1;
	}

	user_led(led_nr, on);

No ugly #ifdef's in this case. What do you think?

Best regards,
Stefan