Re: [PATCH 2/2] ubi: open volumes define in device tree

[Daniel Golle <daniel@makrotopia.org>]

On Sat, Jun 18, 2016 at 09:17:56PM +0200, Hauke Mehrtens wrote:
> This makes it possible to define a volume to open in device tree. This
> is helpful when a root file system is on a ubi layer. Without this
> patch it is only possible to device with with kernel command line
> parameters.
> 
> Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

The example in the documentation doesn't belong to that patch, see
below. Apart from this single [PATCH 2/2]:
Acked-by: Daniel Golle <daniel@makrotopia.org>

> ---
>  Documentation/devicetree/bindings/mtd/ubi.txt | 22 +++++++++++++++++
>  drivers/mtd/ubi/build.c                       | 34 +++++++++++++++++++++++++++
>  2 files changed, 56 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mtd/ubi.txt b/Documentation/devicetree/bindings/mtd/ubi.txt
> index 5fcd47e..f87a7d8 100644
> --- a/Documentation/devicetree/bindings/mtd/ubi.txt
> +++ b/Documentation/devicetree/bindings/mtd/ubi.txt
> @@ -13,6 +13,16 @@ Describe of a UBI layer in device tree.
>   			which have to be assigned to the newly created UBI
>   			device (assigned automatically by default)
>  
> +Partitions on a UBI layer can be defined:
> +
> + - compatible: 		"ubi,volume"
> + - name:		name of the ubi volume to open
> + - ubi-mode:		mode of the ubi volume to open value:
> + 			UBI_READONLY:	1
> + 			UBI_READWRITE:	2
> + 			UBI_EXCLUSIVE:	3
> + 			UBI_METAONLY:	4
> +
>  Example:
>  
>  partitions {
> @@ -29,5 +39,17 @@ partitions {
>  		label = "system_sw";
>  		reg = <0x1c0000 0xc800000>;
>  		compatible = "ubi,device";
> +
> +		rootfsA@0 {
> +			compatible = "ubi,volume";
> +			name = "rootfsA";
> +			ubi-mode = <1>;
> +		};
> +
> +		data_vol@0 {
> +			compatible = "ubi,volume";
> +			name = "data_vol";
> +			ubi-mode = <2>;
> +		};

This is an example for the 'ubi,volume' while the patch introduces
support for 'ubi,device'.


>  	};
>  };
> diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
> index 16baeb5..1c22533 100644
> --- a/drivers/mtd/ubi/build.c
> +++ b/drivers/mtd/ubi/build.c
> @@ -1,6 +1,7 @@
>  /*
>   * Copyright (c) International Business Machines Corp., 2006
>   * Copyright (c) Nokia Corporation, 2007
> + * Copyright (c) 2016 Hauke Mehrtens <hauke@hauke-m.de>
>   *
>   * 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
> @@ -33,6 +34,7 @@
>  #include <linux/module.h>
>  #include <linux/moduleparam.h>
>  #include <linux/stringify.h>
> +#include <linux/of.h>
>  #include <linux/namei.h>
>  #include <linux/stat.h>
>  #include <linux/miscdevice.h>
> @@ -43,6 +45,7 @@
>  #include <linux/slab.h>
>  #include <linux/major.h>
>  #include "ubi.h"
> +#include "../mtdcore.h"
>  
>  /* Maximum length of the 'mtd=' parameter */
>  #define MTD_PARAM_LEN_MAX 64
> @@ -1205,6 +1208,7 @@ static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
>  static int __init ubi_init(void)
>  {
>  	int err, i, k;
> +	struct mtd_info *mtd_it;
>  
>  	/* Ensure that EC and VID headers have correct size */
>  	BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
> @@ -1285,6 +1289,36 @@ static int __init ubi_init(void)
>  		}
>  	}
>  
> +	mtd_for_each_device(mtd_it) {
> +		struct mtd_info *mtd;
> +		u32 ubi_num = 0;
> +		u32 vid_hdr_offs = 0;
> +		u32 max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT;
> +
> +		mtd = get_mtd_device(mtd_it, -1);
> +
> +		if (!of_device_is_compatible(mtd->dev.of_node, "ubi,device")) {
> +			put_mtd_device(mtd);
> +			continue;
> +		}
> +
> +		of_property_read_u32(mtd->dev.of_node, "vid_hdr_offs",
> +				     &vid_hdr_offs);
> +		of_property_read_u32(mtd->dev.of_node, "max_beb_per1024",
> +				     &max_beb_per1024);
> +		of_property_read_u32(mtd->dev.of_node, "ubi_num", &ubi_num);
> +
> +		mutex_lock(&ubi_devices_mutex);
> +		err = ubi_attach_mtd_dev(mtd, ubi_num, vid_hdr_offs,
> +					 max_beb_per1024);
> +		mutex_unlock(&ubi_devices_mutex);
> +		if (err < 0) {
> +			pr_err("UBI error: cannot attach mtd%d",
> +			       mtd->index);
> +		}
> +		put_mtd_device(mtd);
> +	}
> +
>  	err = ubiblock_init();
>  	if (err) {
>  		pr_err("UBI error: block: cannot initialize, error %d", err);
> -- 
> 2.8.1
> 
> 
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