[RFC 1/4] ARM: tegra: Move SoC drivers to drivers/soc/tegra

On Fri, Jun 27, 2014 at 01:30:04PM -0400, Santosh Shilimkar wrote:

+Arnd, Greg, Catalin and Kumar,

On Friday 27 June 2014 12:58 PM, Thierry Reding wrote:

quoted

From: Thierry Reding <redacted>

These drivers are closely coupled and need to be moved as a whole. One
reason for moving them out of arch/arm/mach-tegra is to allow them to be
shared with 64-bit ARM.

Signed-off-by: Thierry Reding <redacted>
---
 arch/arm/mach-tegra/Makefile                       | 32 --------
 arch/arm/mach-tegra/common.h                       |  4 -
 arch/arm/mach-tegra/io.c                           | 27 +++++-
 arch/arm/mach-tegra/pmc.h                          | 62 --------------
 arch/arm/mach-tegra/tegra.c                        |  9 --
 drivers/soc/Makefile                               |  1 +
 drivers/soc/tegra/Makefile                         | 34 ++++++++
 .../soc/tegra}/cpuidle-tegra114.c                  |  0
 .../soc/tegra}/cpuidle-tegra20.c                   |  6 +-
 .../soc/tegra}/cpuidle-tegra30.c                   |  0
 .../arm/mach-tegra => drivers/soc/tegra}/cpuidle.c |  0
 .../arm/mach-tegra => drivers/soc/tegra}/cpuidle.h |  3 -
 .../mach-tegra => drivers/soc/tegra}/flowctrl.c    |  0
 .../mach-tegra => drivers/soc/tegra}/flowctrl.h    |  2 -
 .../arm/mach-tegra => drivers/soc/tegra}/headsmp.S |  0
 .../arm/mach-tegra => drivers/soc/tegra}/hotplug.c |  0
 {arch/arm/mach-tegra => drivers/soc/tegra}/iomap.h |  0
 .../arm/mach-tegra => drivers/soc/tegra}/irammap.h |  0
 {arch/arm/mach-tegra => drivers/soc/tegra}/irq.c   |  1 -
 {arch/arm/mach-tegra => drivers/soc/tegra}/irq.h   |  6 --
 .../arm/mach-tegra => drivers/soc/tegra}/platsmp.c |  5 --
 .../mach-tegra => drivers/soc/tegra}/pm-tegra20.c  |  0
 .../mach-tegra => drivers/soc/tegra}/pm-tegra30.c  |  0
 {arch/arm/mach-tegra => drivers/soc/tegra}/pm.c    |  0
 {arch/arm/mach-tegra => drivers/soc/tegra}/pm.h    |  4 +-
 {arch/arm/mach-tegra => drivers/soc/tegra}/pmc.c   |  0
 drivers/soc/tegra/pmc.h                            | 35 ++++++++
 .../mach-tegra => drivers/soc/tegra}/powergate.c   |  0
 .../soc/tegra}/reset-handler.S                     |  0
 {arch/arm/mach-tegra => drivers/soc/tegra}/reset.c |  0
 {arch/arm/mach-tegra => drivers/soc/tegra}/reset.h |  2 -
 .../soc/tegra}/sleep-tegra20.S                     |  0
 .../soc/tegra}/sleep-tegra30.S                     |  0
 {arch/arm/mach-tegra => drivers/soc/tegra}/sleep.S |  0
 {arch/arm/mach-tegra => drivers/soc/tegra}/sleep.h |  2 -
 include/linux/tegra-soc.h                          | 95 ++++++++++++++++++++++
 36 files changed, 195 insertions(+), 135 deletions(-)
 delete mode 100644 arch/arm/mach-tegra/common.h
 delete mode 100644 arch/arm/mach-tegra/pmc.h
 create mode 100644 drivers/soc/tegra/Makefile
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/cpuidle-tegra114.c (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/cpuidle-tegra20.c (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/cpuidle-tegra30.c (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/cpuidle.c (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/cpuidle.h (91%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/flowctrl.c (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/flowctrl.h (98%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/headsmp.S (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/hotplug.c (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/iomap.h (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/irammap.h (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/irq.c (99%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/irq.h (83%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/platsmp.c (98%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/pm-tegra20.c (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/pm-tegra30.c (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/pm.c (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/pm.h (94%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/pmc.c (100%)
 create mode 100644 drivers/soc/tegra/pmc.h
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/powergate.c (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/reset-handler.S (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/reset.c (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/reset.h (97%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/sleep-tegra20.S (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/sleep-tegra30.S (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/sleep.S (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/sleep.h (98%)

NAK for this patch.

You are using drivers/soc/* as a dump yard for your SOC code which
is not the intention we created drivers/soc/.

That was not my intention. What remains in arch/arm/mach-tegra at this
point doesn't actually have a corresponding subsystem (well, except
maybe the cpuidle code).

Its really for subsystem drivers which doesn't have appropriate
home in Linux kernel today. From your above patch ...

quoted

 rename {arch/arm/mach-tegra => drivers/soc/tegra}/cpuidle-tegra114.c (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/cpuidle-tegra20.c (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/cpuidle-tegra30.c (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/cpuidle.c (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/cpuidle.h (91%)

This should go into drivers/idle/*. if you have dependencies, please sort
them out.

What exactly is the difference between drivers/idle and drivers/cpuidle?
There's an intel_idle driver in drivers/idle that includes cpuidle.h and
registers with that subsystem. But there's also an i7300_idle driver
that doesn't.

drivers/cpuidle seems like a better fit. I'll look into moving the code
there.

quoted

 rename {arch/arm/mach-tegra => drivers/soc/tegra}/reset-handler.S (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/reset.c (100%)
 rename {arch/arm/mach-tegra => drivers/soc/tegra}/reset.h (97%)

subsystem: drivers/power/reset/

drivers/power/reset seems to be for drivers that register functions to
reset a board. The above code for Tegra doesn't do that. Rather it sets
up the reset handlers for secondary CPUs and for suspend/resume.

For tegra/*pm*/, you can use drivers/power or drivers/base/power/

drivers/power seems to be exclusively battery charger drivers. The pm.c,
pm-*.c and sleep-*.S set up suspend/resume. That doesn't seem to belong
in drivers/base/power either.

pmc.c implements various routines to access the power management
controller, some of which is needed by suspend/resume, some of it is
needed by SMP. powergate.c implements a subset of the PMC that needs to
be exported to drivers to enable power partitions on the SoC. I'm not
aware of subsystems that deal with this kind of driver.

For SMP boot, ARMv8 expecting to have either PSCI based implementation or
device tree based boot scheme. you can move towards that model if possible.

But we also have the code for SMP on 32-bit ARM. Should that remain in
arch/arm/mach-tegra or can it move to drivers/soc/tegra?

So the only thing in the above that I think could be moved somewhere
else is the cpuidle drivers. Or do you have any other suggestions for
the remaining code?

Thierry
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