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From: Sergei Shtylyov <sshtylyov@ru•mvista.com>
To: Milton Miller <miltonm@bga•com>
Cc: ppcdev <linuxppc-dev@ozlabs•org>
Subject: Re: [PATCH] powerpc: Create "rom" (MTD) device prpmc2800
Date: Sun, 03 Jun 2007 21:29:11 +0400	[thread overview]
Message-ID: <4662FA67.3020107@ru.mvista.com> (raw)
In-Reply-To: <7fc919fce0761f861be3069a853d3169@bga.com>

Hello.

Milton Miller wrote:

>>Find the "rom" device for the prpmc2800 and create a device for it.
>>The device will be picked up by the code in 
>>drivers/mtd/maps/physmap_of.c
>>and will setup MTD on that FLASH device.

> ...

>> /*
>>+ * Register a platform device for MTD.
>>+ */
>>+static int __init prpmc2800_register_mtd(void)
>>+{
>>+       struct device_node *np;
>>+
>>+       np = of_find_compatible_node(NULL, "rom", "direct-mapped");
>>+       of_platform_device_create(np, np->name, NULL);
>>+}
>>+arch_initcall(prpmc2800_register_mtd);

> I think "direct-mapped" as compatible is a bit too broad or vague.

    It's actually not -- it means simple 1:1 address mapping (w/o explicit 
byte-swapping and such).

> The compatible is supposed to be useable to find and match a driver
> without regard to the name of the node.  Perhaps direct-mapped-rom?
> (as opossed to a direct-mapped-ram, sram, or some width flash bank).

    Note that we're matching by both "device_type" and "compatible".

> Actually, looking back at your device tree {1], your list several
> properties for flash, including bank-width and partition names.
> Perhaps first compatible should be direct-mapped-partitioned-flash,
> direct-mapped-partitioned-rom, direct-mapped-rom  (to me a
> direct-mapped-rom driver would expose one section of address space
> read-only).

    This would serve no purpose, as the driver that would catches all these is 
signle one, drivers/mtd/maps/physmap_of.c...

> I'm assuming that your driver for this "direct-mapped"
> device will look at these properties from the of device node and
> call the mtd layer somewhat directly with their contents.

    Yeah, it does.

> [1] http://ozlabs.org/pipermail/linuxppc-dev/2007-May/035858.html

> milton

> PS: I know you've posted this a few times.  I'm just behind in
> my reading and  replying :-).

WBR, Sergei

  parent reply	other threads:[~2007-06-03 17:27 UTC|newest]

Thread overview: 81+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-06-02  4:30 [PATCH] powerpc: Create "rom" (MTD) device prpmc2800 Milton Miller
2007-06-02  7:39 ` Benjamin Herrenschmidt
2007-06-03 16:10   ` Sergei Shtylyov
2007-06-03 17:36     ` Segher Boessenkool
2007-06-03 18:03       ` Sergei Shtylyov
2007-06-03 18:25         ` Segher Boessenkool
2007-06-03 18:36           ` Sergei Shtylyov
2007-06-03 18:46             ` Segher Boessenkool
2007-06-03 19:16               ` Sergei Shtylyov
2007-06-03 21:04         ` Benjamin Herrenschmidt
2007-06-04 12:34           ` Sergei Shtylyov
2007-06-04 14:37             ` Segher Boessenkool
2007-06-04 14:49               ` Sergei Shtylyov
2007-06-07 14:53           ` David Woodhouse
2007-06-07 15:49             ` Segher Boessenkool
2007-06-07 14:47         ` David Woodhouse
2007-06-07 15:32           ` Segher Boessenkool
2007-06-02  8:53 ` Segher Boessenkool
2007-06-03 16:22   ` Sergei Shtylyov
2007-06-03 17:40     ` Segher Boessenkool
2007-06-03 18:31       ` Sergei Shtylyov
2007-06-03 18:44         ` Segher Boessenkool
2007-06-03 19:13           ` Sergei Shtylyov
2007-06-03 19:56             ` Segher Boessenkool
2007-06-03 20:26               ` Sergei Shtylyov
2007-06-04  8:07                 ` Segher Boessenkool
2007-06-04 13:34                   ` Sergei Shtylyov
2007-06-07 15:00                 ` David Woodhouse
2007-06-07 15:55                   ` Segher Boessenkool
2007-06-07 16:05                     ` David Woodhouse
2007-06-07 16:46                       ` Segher Boessenkool
2007-06-12  4:44                     ` David Gibson
2007-06-12 10:53                       ` Segher Boessenkool
2007-06-13  3:16                         ` David Gibson
2007-06-13  5:05                           ` Segher Boessenkool
2007-06-13  6:11                             ` David Gibson
2007-06-13  9:10                               ` Segher Boessenkool
2007-06-15  4:12                                 ` David Gibson
2007-06-15 11:22                                   ` Segher Boessenkool
2007-06-15  4:14                     ` David Gibson
2007-06-15  8:42                       ` Segher Boessenkool
2007-06-15  8:47                         ` David Woodhouse
2007-06-15  8:59                           ` Segher Boessenkool
2007-06-03 21:12     ` Benjamin Herrenschmidt
2007-06-04  8:11       ` Segher Boessenkool
2007-06-04 13:16         ` Sergei Shtylyov
2007-06-04 12:41       ` Sergei Shtylyov
2007-06-04 14:49         ` Segher Boessenkool
2007-06-04 15:54           ` Sergei Shtylyov
2007-06-03 17:29 ` Sergei Shtylyov [this message]
2007-06-03 17:45   ` Segher Boessenkool
2007-06-03 18:18     ` Sergei Shtylyov
2007-06-03 18:43       ` Segher Boessenkool
2007-06-03 18:59         ` Sergei Shtylyov
2007-06-03 19:48           ` Segher Boessenkool
2007-06-03 20:10             ` Sergei Shtylyov
2007-06-04  8:02               ` Segher Boessenkool
2007-06-04 19:40 ` Mark A. Greer
  -- strict thread matches above, loose matches on Subject: below --
2007-06-01 23:20 Mark A. Greer
2007-06-02  8:46 ` Segher Boessenkool
2007-06-04 20:56 ` Mark A. Greer
2007-06-05 20:35   ` Sergei Shtylyov
2007-06-05 21:11     ` Mark A. Greer
2007-06-06 12:41       ` Sergei Shtylyov
2007-06-07 15:08         ` David Woodhouse
2007-06-06  2:39   ` David Gibson
2007-06-07 13:30     ` Segher Boessenkool
2007-06-12  4:42       ` David Gibson
2007-06-12 10:50         ` Segher Boessenkool
2007-06-13  6:12           ` David Gibson
2007-06-13  9:13             ` Segher Boessenkool
2007-06-13  9:19               ` David Gibson
2007-06-13  9:37                 ` Segher Boessenkool
2007-06-14  4:29                   ` David Gibson
2007-06-14  8:00                     ` Segher Boessenkool
2007-06-14 12:39                     ` Sergei Shtylyov
2007-06-14 13:20                       ` Segher Boessenkool
2007-06-14 12:48           ` Sergei Shtylyov
2007-06-14 13:18             ` Segher Boessenkool
2007-06-14 12:50         ` Sergei Shtylyov
2007-06-14 13:43           ` Segher Boessenkool

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