[U-Boot] [PATCH v5] Tegra: T210: Add QSPI driver

[Tom Warren]

Jagan,

> -----Original Message-----
> From: Jagan Teki [mailto:jteki at openedev.com]
> Sent: Friday, November 06, 2015 9:40 AM
> To: Tom Warren <TWarren at nvidia.com>
> Cc: u-boot at lists.denx.de; Stephen Warren <swarren at nvidia.com>;
> tomcwarren3959 at gmail.com
> Subject: Re: [U-Boot] [PATCH v5] Tegra: T210: Add QSPI driver
> 
> On 6 November 2015 at 22:01, Tom Warren <TWarren at nvidia.com> wrote:
> > Jagan,
> >
> > Ping!
> >
> >> -----Original Message-----
> >> From: Tom Warren
> >> Sent: Thursday, October 29, 2015 12:33 PM
> >> To: 'Jagan Teki' <jteki at openedev.com>
> >> Cc: u-boot at lists.denx.de; Stephen Warren <swarren at nvidia.com>;
> >> tomcwarren3959 at gmail.com; Yen Lin <yelin at nvidia.com>
> >> Subject: RE: [U-Boot] [PATCH v5] Tegra: T210: Add QSPI driver
> >>
> >> Jagan,
> >>
> >> > -----Original Message-----
> >> > From: Jagan Teki [mailto:jteki at openedev.com]
> >> > Sent: Thursday, October 29, 2015 10:34 AM
> >> > To: Tom Warren <TWarren at nvidia.com>
> >> > Cc: u-boot at lists.denx.de; Stephen Warren <swarren at nvidia.com>;
> >> > tomcwarren3959 at gmail.com
> >> > Subject: Re: [U-Boot] [PATCH v5] Tegra: T210: Add QSPI driver
> >> >
> >> > On 28 October 2015 at 21:25, Tom Warren <TWarren at nvidia.com>
> wrote:
> >> > > Jagan,
> >> > >
> >> > >> -----Original Message-----
> >> > >> From: Tom Warren
> >> > >> Sent: Monday, October 26, 2015 1:56 PM
> >> > >> To: u-boot at lists.denx.de
> >> > >> Cc: Stephen Warren <swarren at nvidia.com>;
> >> tomcwarren3959 at gmail.com;
> >> > >> jteki at openedev.com; Yen Lin <yelin at nvidia.com>; Tom Warren
> >> > >> <TWarren at nvidia.com>
> >> > >> Subject: [PATCH v5] Tegra: T210: Add QSPI driver
> >> > >>
> >> > >> This is the normal Tegra SPI driver modified to work with the
> >> > >> QSPI controller in Tegra210. It does not do 2x/4x transfers or
> >> > >> any other QSPI
> >> > protocol.
> >> > >>
> >> > >> Signed-off-by: Yen Lin <yelin at nvidia.com>
> >> > >> Signed-off-by: Tom Warren <twarren at nvidia.com>
> >> >
> >> > Reviewed-by: Jagan Teki <jteki at openedev.com>
> >> >
> >> > >> ---
> >> > >> Changes in v2:
> >> > >> - Drop defconfig and pinmux files, this is a driver-only patch.
> >> > >> - If/when pinmux tables have been updated for P2371/P2571,
> >> > >> another
> >> > >> - patch will be sent to enable the QSPI driver on those boards.
> >> > >> Changes in v3:
> >> > >> - removed status reg write/clear in claim_bus(), done in xfer()
> >> > >> Changes in
> >> > v4:
> >> > >> - added timeout in wait for FIFO flush status in xfer()
> >> > >> - used BIT and GENMASK macros throughout
> >> > >> - minor changes in copyright message in driver and Kconfig help
> >> > >> Changes in v5:
> >> > >> - commented on reason for udelay before setting GO bit, as per Yen
> Lin.
> >> > >
> >> > > Can you PTAL and see if this meets all your requests? Thanks.
> >> >
> >> > OK with this? Can you point the dts and config patch for this
> >> > driver - I couldn't find it either.
> >> The intent is to only upstream the driver. The DTS already contains
> >> the QSPI node (see spi at 0,70410000), and the defconfig/pinmux-config.h
> >> changes won't be merged since there's no T210 board (from Nvidia)
> >> that has a SPI part on the QSPI controller currently. There is a
> >> customer with their own board that needs this driver upstreamed so they
> can pull it down into their custom U-Boot repo.
> >> However, if you search the list for my original patch ('[PATCH]
> >> Tegra210: add QSPI driver'), you'll see examples of the p2571
> >> def_config/pinmux configs that can be used if someone does wish to pop a
> SPI chip on their T210 board, etc.
> 
> I'm little concern about stale driver without have any board to use, any
> possibility that T210 will be in ML - because I have removed some in past as
> there is no progress on the drivers as no board's been used for long time.

There are downstream (customer and in-house dev) boards that use/will use this driver, hence the need to upstream it. It just happens to be true that no _current_ T210 boards have a SPI chip hanging off of the QSPI pins at this time.

I'm not sure what 'T210 will be in ML' means, though.

As to progress on the driver, it works fine as-is - I'm not sure what progress you are looking for - I'm certain there are a lot of drivers in U-Boot that have been written once and remained virtually untouched since then, and continue to work just fine.

> 
> >>
> >> So with that in mind, will you take this in to the SPI repo, or can I
> >> take it in via the Tegra repo instead? I'm fine with either course.
> >>
> >> Tom
> >> --
> >> nvpublic
> >>
> >> >
> >> > >
> >> > > And do you want to take this in, or can I take it in via the Tegra repo?
> >> > >
> >> > > Tom
> >> > > --
> >> > > nvpublic
<snip>
> --
> Jagan | openedev.
--
nvpublic