Re: [PATCH v2 1/4] dt: bindings: mmc: Document the practice of using subnodes for slots
From: Hans de Goede <hidden>
Date: 2014-06-02 08:33:37
Also in:
linux-arm-kernel, linux-mmc
Hi, On 06/02/2014 10:29 AM, Ulf Hansson wrote:
On 1 June 2014 11:23, Hans de Goede [off-list ref] wrote:quoted
Hi, On 05/31/2014 10:13 PM, Olof Johansson wrote:quoted
On Sat, May 31, 2014 at 12:03 PM, Hans de Goede [off-list ref] wrote:quoted
The following existing MMC host controller bindings use slot subnodes: Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt Documentation/devicetree/bindings/mmc/k3-dw-mshc.txt Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt Documentation/devicetree/bindings/mmc/atmel-hsmci.txt Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt This commit documents this practice in the standard mmc bindings documentation. Signed-off-by: Hans de Goede <redacted>There are today only two drivers that use this kind of binding, dw_mmc and the at91 one.Correct.quoted
Neither seems to actually ever have been used with more than one slot. I doubt anyone building an exynos-based system will ever do a multi-slot solution, and it seems that the at91 driver doesn't actually handle more than one slot. I'm personally not that excited about complicating the bindings by opening up for this -- I would rather work towards removing the concept of slots if it's one of those things that are going to remain unused. We have actually been talking about reworking the dw_mmc binding to remove the slot concept (and simplify the driver by doing so).I'm fine with removing the slot subnode, I added it because of it being brought up in the powerup sequence discussion. I explicitly asked there if adding such a subnode level was seen as desirable but nobody answered :| Anyways, either way works for me. I can do a v3 dropping the slot subnode level again. I would really like to move forward with a decision on how-to represent non probable info for sdio devices in device nodes. So do you have any other remarks other then that the slot subnode should be dropped ? And if not can you please review and ack (*) v3 of this patch-set once I've send it? Chris Ball and Ulf Hansson, what is your take on this, are you willing to take this patch set? And do you want it with or without the slot subnodes ?I certainly appreciate you working actively on this Hans, I will look into the patchset as soon as I can.
Thanks. If I read you correctly below, then you want the slot nodes to be removed, correct? In that case it is probably best if you wait reviewing until I've done a v3, with the slot nodes removed. I hope to find some time to do this this evening (CET). Regards, Hans
I share Olof's view about the slot nodes, we must not add DT bindings that isn't really needed. Regarding the slot subnodes; Jaehoon Chung recently posted a patchset for adding the parsing of it, intended for dwmmc. I withdraw my ack for it, and let's try to go in the other direction instead. [PATCHv3 0/4] mmc: fixed the mmc_of_parse for dwmmc. Thus I suggest we should clean-up host drivers to support only one card per host, and entirely skip the slot concept. Kind regards Uffequoted
Thanks & Regards, Hans *) Assuming you don't find any issues