Re: [PATCH v2 7/7] commands: add of_overlay command for device tree overlays

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

On 9/11/19 11:28 AM, Michael Tretter wrote:
> On Wed, 11 Sep 2019 09:55:34 +0200, Ahmad Fatoum wrote:
>> On 9/6/19 3:20 PM, Michael Tretter wrote:
>>> Add a new command "of_overlay" for applying device tree overlays,
>>> because it does not really fit into any other device tree related
>>> command and would create a mess with the command options.
>>>
>>> Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
>>>
>>> ---
>>> Changelog:
>>>
>>> v1->v2: none
>>> ---
>>>  commands/Kconfig      | 12 ++++++
>>>  commands/Makefile     |  1 +
>>>  commands/of_overlay.c | 89 +++++++++++++++++++++++++++++++++++++++++++
>>>  3 files changed, 102 insertions(+)
>>>  create mode 100644 commands/of_overlay.c
>>>
>>> diff --git a/commands/Kconfig b/commands/Kconfig
>>> index 039fd7d1ac..01d82031ad 100644
>>> --- a/commands/Kconfig
>>> +++ b/commands/Kconfig
>>> @@ -2088,6 +2088,18 @@ config CMD_OF_FIXUP_STATUS
>>>  	  Register a fixup to enable or disable a device tree node.
>>>  	  Nodes are enabled on default. Disabled with -d.
>>>  
>>> +config CMD_OF_OVERLAY
>>> +	tristate
>>> +	select OFTREE  
>>
>> This should depend or select OF_OVERLAY, otherwise:
>> ./commands/of_overlay.c:60: undefined reference to `firmware_load_overlay'
> 
> Thanks. Actually, the firmware_load_overlay() function should be stubbed
> and return an error, if FIRMWARE is disabled.

Ye, that would work for the blspec case, because not everyone needs overlays.
For the command though, I'd think that you should ensure at configuration time
that these symbols are enabled.

> 
> Michael
> 
>>
>> Cheers
>> Ahmad
>>
>>> +	prompt "of_overlay"
>>> +	help
>>> +	  of_overlay - register device tree overlay as fixup
>>> +
>>> +	  Usage: of_overlay [-S path] FILE
>>> +
>>> +	  Options:
>>> +		  -S path	load firmware using this search path
>>> +
>>>  config CMD_OFTREE
>>>  	tristate
>>>  	select OFTREE
>>> diff --git a/commands/Makefile b/commands/Makefile
>>> index e69fb5046f..62ad9ce2b2 100644
>>> --- a/commands/Makefile
>>> +++ b/commands/Makefile
>>> @@ -78,6 +78,7 @@ obj-$(CONFIG_CMD_OF_NODE)	+= of_node.o
>>>  obj-$(CONFIG_CMD_OF_DUMP)	+= of_dump.o
>>>  obj-$(CONFIG_CMD_OF_DISPLAY_TIMINGS)	+= of_display_timings.o
>>>  obj-$(CONFIG_CMD_OF_FIXUP_STATUS)	+= of_fixup_status.o
>>> +obj-$(CONFIG_CMD_OF_OVERLAY)	+= of_overlay.o
>>>  obj-$(CONFIG_CMD_MAGICVAR)	+= magicvar.o
>>>  obj-$(CONFIG_CMD_IOMEM)		+= iomemport.o
>>>  obj-$(CONFIG_CMD_LINUX_EXEC)	+= linux_exec.o
>>> diff --git a/commands/of_overlay.c b/commands/of_overlay.c
>>> new file mode 100644
>>> index 0000000000..f929443bfe
>>> --- /dev/null
>>> +++ b/commands/of_overlay.c
>>> @@ -0,0 +1,89 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +/*
>>> + * Copyright (c) 2019 Michael Tretter <m.tretter@pengutronix.de>, Pengutronix
>>> + *
>>> + * 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 version 2
>>> + * as published by the Free Software Foundation.
>>> + *
>>> + * 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.
>>> + */
>>> +
>>> +#include <command.h>
>>> +#include <common.h>
>>> +#include <environment.h>
>>> +#include <fdt.h>
>>> +#include <firmware.h>
>>> +#include <fs.h>
>>> +#include <getopt.h>
>>> +#include <libfile.h>
>>> +#include <of.h>
>>> +
>>> +static int do_of_overlay(int argc, char *argv[])
>>> +{
>>> +	int opt, ret;
>>> +	struct fdt_header *fdt;
>>> +	struct device_node *overlay;
>>> +	const char *search_path = NULL;
>>> +
>>> +	while ((opt = getopt(argc, argv, "S:")) > 0) {
>>> +		switch (opt) {
>>> +		case 'S':
>>> +			search_path = optarg;
>>> +			break;
>>> +		default:
>>> +			return COMMAND_ERROR_USAGE;
>>> +		}
>>> +	}
>>> +
>>> +	if (argc != optind + 1)
>>> +		return COMMAND_ERROR_USAGE;
>>> +
>>> +	fdt = read_file(argv[optind], NULL);
>>> +	if (!fdt) {
>>> +		printf("cannot read %s\n", argv[optind]);
>>> +		return 1;
>>> +	}
>>> +
>>> +	overlay = of_unflatten_dtb(fdt);
>>> +	free(fdt);
>>> +	if (IS_ERR(overlay))
>>> +		return PTR_ERR(overlay);
>>> +
>>> +	if (search_path) {
>>> +		ret = firmware_load_overlay(overlay, search_path);
>>> +		if (ret)
>>> +			goto err;
>>> +	}
>>> +
>>> +	ret = of_register_overlay(overlay);
>>> +	if (ret) {
>>> +		printf("cannot apply oftree overlay: %s\n", strerror(-ret));
>>> +		goto err;
>>> +	}
>>> +
>>> +	return 0;
>>> +
>>> +err:
>>> +	of_delete_node(overlay);
>>> +	return ret;
>>> +}
>>> +
>>> +BAREBOX_CMD_HELP_START(of_overlay)
>>> +BAREBOX_CMD_HELP_TEXT("Options:")
>>> +BAREBOX_CMD_HELP_OPT("-S path", "load firmware using this search path")
>>> +BAREBOX_CMD_HELP_END
>>> +
>>> +BAREBOX_CMD_START(of_overlay)
>>> +	.cmd = do_of_overlay,
>>> +	BAREBOX_CMD_DESC("register device tree overlay as fixup")
>>> +	BAREBOX_CMD_OPTS("[-S path] FILE")
>>> +	BAREBOX_CMD_GROUP(CMD_GRP_MISC)
>>> +	BAREBOX_CMD_HELP(cmd_of_overlay_help)
>>> +BAREBOX_CMD_END
>>>   
>>
> 

-- 
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