[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 11:34 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 6 November 2015 at 23:08, Tom Warren <TWarren at nvidia.com> wrote:
> > 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.
> 
> OK, then take this via tegra repo.
Will do. Thanks for your help/critiques.

Tom
> 
> >
> >>
> >> >>
> >> >> 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?
> 
> thanks!
> --
> Jagan | openedev.