Re: [PATCH v6 6/9] dt-bindings: connector: m2: Add M.2 1620 LGA soldered down connector

[Manivannan Sadhasivam]

On Mon, Mar 23, 2026 at 06:45:15PM +0200, Dmitry Baryshkov wrote:
> On Mon, Mar 23, 2026 at 09:26:04PM +0530, Manivannan Sadhasivam wrote:
> > On Mon, Mar 23, 2026 at 05:14:30PM +0200, Dmitry Baryshkov wrote:
> > > On Mon, Mar 23, 2026 at 07:14:25PM +0530, Manivannan Sadhasivam wrote:
> > > > On Mon, Mar 23, 2026 at 08:39:55AM -0500, Rob Herring wrote:
> > > > > On Mon, Mar 23, 2026 at 7:16 AM Manivannan Sadhasivam <mani@xxxxxxxxxx> wrote:
> > > > > >
> > > > > > On Sun, Mar 22, 2026 at 06:37:13PM -0500, Rob Herring wrote:
> > > > > > > On Tue, Mar 17, 2026 at 09:59:56AM +0530, Manivannan Sadhasivam wrote:
> > > > > > > > Lenovo Thinkpad T14s is found to have a soldered down version of M.2 1620
> > > > > > > > LGA connector. Though, there is no 1620 LGA form factor defined in the M.2
> > > > > > > > spec, it looks very similar to the M.2 Key E connector. So add the
> > > > > > > > "pcie-m2-1620-lga-connector" compatible with "pcie-m2-e-connector" fallback
> > > > > > > > to reuse the Key E binding.
> > > > > > >
> > > > > > > What is LGA?
> > > > > > >
> > > > > >
> > > > > > Land Grid Array
> > > > > >
> > > > > > > If not in the spec, is it really something generic?
> > > > > > >
> > > > > >
> > > > > > Good question. Yes and No! LGA is not something that Lenovo only uses. Other
> > > > > > vendors may also use this form factor. PCIe connectors are full of innovation as
> > > > > > the spec gives room for hardware designers to be as innovative as possible to
> > > > > > save the BOM cost.
> > > > > 
> > > > > innovation == incompatible changes
> > > > > 
> > > > 
> > > > Yes, I was trying to sound nice :)
> > > > 
> > > > > > This is why I do not want to make it Lenovo specific. But if you prefer that, I
> > > > > > can name it as "lenovo,pcie-m2-1620-lga-connector".
> > > > > 
> > > > > Depends if you think that s/w needs to know the differences. Hard to
> > > > > say with a sample size of 1.
> > > > > 
> > > > 
> > > > Sure. Will add the 'lenovo' prefix then.
> > > 
> > > Is it really Lenovo? Or is it some other module vendor, whose LGAs are
> > > being used by Lenovo?
> > > 
> > > I remember that DB820c also used some kind of a module for the WiFi card
> > > (which might be M.2 compatible or might not, I can't find exact docs at
> > > this point).
> > > 
> > 
> > I don't know. These kind of designs might be reused by several vendors. But
> > considering that we should not make it generic, I'd go with Lenovo as that's
> > the only vendor we know as of now.
> 
> ... and later we learn that other vendors use the same idea /pinout,
> then nothing stops us from still telling that it's a
> "lenovo,pcie-m2-something-lga". 
> 

How do you possibly know whether a single vendor has introduced this form factor
or reused by multiple ones? Atleast, I don't have access to such a source to
confirm.

- Mani

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