From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by canuck.infradead.org with esmtps (Exim 4.72 #1 (Red Hat Linux)) id 1P9DS5-0003uz-2u for barebox@lists.infradead.org; Fri, 22 Oct 2010 08:58:19 +0000 Received: from gallifrey.ext.pengutronix.de ([2001:6f8:1178:4:5054:ff:fe8d:eefb] helo=localhost) by metis.ext.pengutronix.de with esmtp (Exim 4.71) (envelope-from ) id 1P9DS3-00063N-AH for barebox@lists.infradead.org; Fri, 22 Oct 2010 10:58:15 +0200 From: Juergen Beisert Date: Fri, 22 Oct 2010 10:58:01 +0200 MIME-Version: 1.0 Content-Disposition: inline Message-Id: <201010221058.01249.jbe@pengutronix.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: barebox-bounces@lists.infradead.org Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH] Add some help using the gpio commands at runtime To: barebox@lists.infradead.org From: Juergen Beisert Subject: [PATCH] Add some help using the gpio commands at runtime Last time I used the gpio commands I was somehow confused about the behaviour of the 'gpio_get_value' command. So, I decided to add some doc for it. Here's the result. Signed-off-by: Juergen Beisert --- Documentation/commands.dox | 1 commands/gpio.c | 61 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 62 insertions(+) Index: barebox-2010.10.0/Documentation/commands.dox =================================================================== --- barebox-2010.10.0.orig/Documentation/commands.dox +++ barebox-2010.10.0/Documentation/commands.dox @@ -10,6 +10,7 @@ @li @subpage edit_command @li @subpage erase_command @li @subpage export_command +@li @subpage gpio_for_users @li @subpage tftp_command @li @subpage loadenv_command @li @subpage mount_command Index: barebox-2010.10.0/commands/gpio.c =================================================================== --- barebox-2010.10.0.orig/commands/gpio.c +++ barebox-2010.10.0/commands/gpio.c @@ -120,3 +120,64 @@ BAREBOX_CMD_START(gpio_direction_output) BAREBOX_CMD_HELP(cmd_gpio_direction_output_help) BAREBOX_CMD_END +/** +@page gpio_for_users Runtime GPIO handling + +@section regular_gpio General usage information + +These commands are available if the symbol @b CONFIG_GENERIC_GPIO and +@b CONFIG_CMD_GPIO are enabled in the Kconfig. + +@note All gpio related commands take a number to identify the pad. This +number is architecture dependend. There may be no intuitional correlation +between available pads and the GPIO numbers to be used in the commands. Due +to this its also possible the numbers change between @b barebox releases. + +@section gpio_dir_out Switch a pad into an output GPIO +@verbatim +gpio_direction_output +@endverbatim +- @b gpio_no Architecture dependend GPIO number +- @b initial_value Output value the pad should emit + +@note To avoid glitches on the pad's line, the routines will first setting up +the pad's value and after that switching the pad itself to output (if the +silicon is able to do so) + +@note If the pad is already configured into a non GPIO mode (if available) +this command may fail (silently) + +@section gpio_dir_in Switch a pad into an input GPIO +@verbatim +gpio_direction_input +@endverbatim +- @b gpio_no Architecture dependend GPIO number + +@note If the pad is already configured into a non GPIO mode (if available) +this command may fail (silently) + +@section gpio_get_value Read in the value of an GPIO input pad +@verbatim +gpio_get_value +@endverbatim + +Reads in the current pad's line value from the given GPIO number. It returns +the value as a shell return code. There is no visible output at stdout. You +can check the return value by using "echo $?" + +@note If the return code is not '0' or '1' it's meant as an error code. + +@note If the pad is not configured for GPIO mode this command may fail +(silently) and returns garbage + +@section gpio_set_value Set a new value to a GPIO output pad +@verbatim +gpio_set_value +@endverbatim +- @b gpio_no Architecture dependend GPIO number +- @b value Output value the pad should emit + +Sets a new output @b value to the pad with GPIO number @b gpio_no + +@note If the pad is not configured for GPIO mode this command may fail (silently) +*/ -- Pengutronix e.K. | Juergen Beisert | Linux Solutions for Science and Industry | Phone: +49-8766-939 228 | Vertretung Sued/Muenchen, Germany | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de/ | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox