From mboxrd@z Thu Jan  1 00:00:00 1970
From: b32955@freescale.com (Huang Shijie)
Date: Tue, 29 Apr 2014 13:18:34 +0800
Subject: [PATCH v2 02/10] mtd: spi-nor: add a new field for spi_nor{}
In-Reply-To: <201404282223.26174.marex@denx.de>
References: <1398657227-20721-1-git-send-email-b32955@freescale.com>
 <1398657227-20721-3-git-send-email-b32955@freescale.com>
 <201404282223.26174.marex@denx.de>
Message-ID: <20140429051832.GC21064@localhost>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Mon, Apr 28, 2014 at 10:23:26PM +0200, Marek Vasut wrote:
> On Monday, April 28, 2014 at 05:53:39 AM, Huang Shijie wrote:
> > We need the SPI NOR child node to store some specific features, such as the
> > dummy cycles for the DDR Quad read.
> > 
> > But now, we only have the @dev field in the spi_nor{}. The @dev may points
> > to a spi_device{} for m25p80, while it may points to a platform_deivice{}
> > for the SPI NOR controller, such as fsl_quadspi.c.
> > 
> > It is not convenient for us to get come information from the SPI NOR flash.
> > 
> > This patch adds a new field @np to spi_nor{}, it points to the child node
> > for the SPI NOR flash.
> > 
> > Signed-off-by: Huang Shijie <b32955@freescale.com>
> 
> Just handle the case where dev->of_node == NULL instead ?
It is not enough. 

For the m25p80.c, @dev stands for a child node for the SPI master,
and it points to a spi_device{}. Yes, in this case, the dev->of_node is NULL.

But for the fsl_quadspi or other SPI NOR drivers, the @dev stands for the controller
itself, the @dev->of_node is a list of the child nodes, so we can _NOT_ know which
child node we are working at now.


So it's better to add a new field @np for the spi-nor{} which points the
child node we are working at.

thanks
Huang Shijie