From mboxrd@z Thu Jan  1 00:00:00 1970
From: mnalajal@codeaurora.org (Murali Nalajala)
Date: Sat, 16 Apr 2011 15:29:44 +0530
Subject: [PATCH 2/2] mtd: msm_nand: Add initial msm nand driver support.
In-Reply-To: <1302942029.2308.1.camel@koala>
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Message-ID: <4DA96890.2070207@codeaurora.org>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 4/16/2011 1:50 PM, Artem Bityutskiy wrote:
> On Fri, 2011-04-15 at 20:20 +0530, Murali Nalajala wrote:
>> On 4/15/2011 3:21 PM, Artem Bityutskiy wrote:
>>> On Tue, 2011-03-01 at 06:17 +0530, Murali Nalajala wrote:
>>>> +#define pr_fmt(fmt) "%s:" fmt, __func__
>>>> +
>>>> +#include<linux/kernel.h>
>>>> +#include<linux/mtd/mtd.h>
>>>> +#include<linux/mtd/nand.h>
>>>> +#include<linux/mtd/partitions.h>
>>>> +#include<linux/platform_device.h>
>>>> +#include<linux/sched.h>
>>>> +#include<linux/slab.h>
>>>> +#include<linux/dma-mapping.h>
>>>> +#include<asm/mach/flash.h>
>>>> +#include<mach/dma.h>
>>>> +
>>>> +#include "msm_nand.h"
>>>> +
>>>> +unsigned long msm_nand_phys;
>>>
>>> No global variables like this please. Here is how you use them:
>>>
>>> +extern unsigned long msm_nand_phys;
>>
>> extern declaration in the 'C' file causing warning. We are in plan to
>> upload the OneNAND changes soon which makes use of the same .h file.
>
> So you say that OneNAND (an independent driver) is going to use this
> variable? Are you also going to export it?

I haven't decided yet when oneNAND driver come in still it is under 
discussion. There is a chance that if OneNAND comes as an individual 
driver then i have to export this variable.

Can i export this variable now? What is your suggestion?

>
>>> +#define MSM_NAND_REG(off) (msm_nand_phys + (off))
>>> +
>>> +#define MSM_NAND_FLASH_CMD            MSM_NAND_REG(0x0000)
>>> +#define MSM_NAND_ADDR0                MSM_NAND_REG(0x0004)
>>>
>>> Could you please make the macros to take the "struct msm_nand_chip
>>> *chip" argument instead, and store the pase address there. Do not hide
>>> the fact that those macros are actually functions, not constant - this
>>> is error prone.
>>>
>>> Besides, I'm do not know your HW, but if you have several controllers
>>> with various base addresses - your driver won't work.
>>
>> you are correct, we have multiple controllers, which breaks this logic
>> in future.
>
> So then make your macros to accept the base address as an argument
> instead please.
>


Thanks,
Murali N

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