[ no change in content, but order shuffling for better application ]

On Tue, Aug 06, 2013 at 23:31 +0200, Gerhard Sittig wrote:

[ this is an overview on how to split the series if necessary ]

On Tue, Aug 06, 2013 at 22:43 +0200, Gerhard Sittig wrote:

quoted

this series
- fixes several drivers that are used in the MPC512x platform (UART,
  SPI, ethernet, PCI, USB, CAN, NAND flash, video capture) in how they
  handle clocks (appropriately acquire and setup them, hold references
  during use, release clocks after use)
- introduces support for the common clock framework (CCF, COMMON_CLK
  Kconfig option) in the PowerPC based MPC512x platform, which brings
  device tree based clock lookup as well

although the series does touch several subsystems -- tty (serial), spi,
net (can, fs_enet), mtd (nfc), usb, i2c, media (viu), and dts -- all of
the patches are strictly clock related or trivial

it appears most appropriate to take this series through either the clk
or the powerpc trees after it has passed review and other subsystem
maintainers ACKed the clock setup related driver modifications

It was suggested that the series may not be kept together when
applying, i.e. that individual patches may need to take separate
routes through individual subsystem trees.

Here is how the parts of the series interact:
- parts 01-14 are apparent fixes and improvements to existing
  drivers, they may immediately get applied via their respective
  subsystems when they are considered acceptable in review
  (number 13 already was taken into clk-next)
- parts 15-16 are device tree improvements (providing previously
  lacking information on the hardware, plus introducing support
  for symbolic references in DT nodes), and can get applied
  immediately via their respective subsystem
- part 17 introduces the platform clock driver which provides
  common clock support (uses shared drivers and common
  infrastructure, is an OF clock provider) -- this patch
  introduces _and_ enables the driver which strictly depends on
  the device tree update from part 16, and when common clock
  support gets enabled all peripheral drivers shall have received
  their clock API use cleanup
- part 18 introduces clock specs in the device tree which is used
  for client side lookups (from within peripheral drivers), this
  part must not get applied before the OF clock provider from
  part 17
- parts 19-21 and 23-28 further adjust peripheral drivers _after_
  the common clock support and OF clock lookup have become
  available, they strictly depend on parts 17 and 18, finally
  bring peripheral drivers into the common clock world and remove
  workarounds in the backend which support migration
- parts 22 and 29-31 finally remove remaining compat and
  migration stuff that has become obsolete after everything else
  was adjusted (I'd happily re-spin the series to move 22 to the
  end if eliminating this seemingly out-of-order item helps,
  currently it's at that position since it finishes what patch 20
  and 21 have prepared, while I did not dare to squash SPI and
  UART related patches since they reside in different subsystems)

The above results in the following stages, when the series needs
to get split:
- parts 01-16 could be taken immediately and need not be kept in
  any order, as they don't depend on each other
- parts 17-18 could be taken after 01-16 all are in place (while
  18 requires 17)
- parts 19-28 (see the remark on 22) could be taken after 17 and
  18 are in place (22 depends on 20 and 21 but may get moved to
  any later position at will, all other parts don't depend on
  each other and can get applied in any order)
- parts 29-31 (and 22 if not applied so far) could be taken after
  all parts up to 28 were applied

Here I erred.  The order of the patches within phase 3 appears to
actually matter.  I'm sorry for bothering you again.

While the _content_ of the patches (which manipulation gets done
to the source) is correct and independent from neighbour patches,
yet a patch in that third phase will change the _context_ of
subsequent patches.  The sum of all the patches applied will be
identical again, but changed order of application may cause
conflicts (regardless of how simple to resolve they may be).

Build and run tests and the organization of v4 (immediate removal
upon driver adjustment) have shown that removing a migration
workaround in the very moment where driver adjustment obsoletes
it keeps the system operational.  I consider this a very positive
feature, and would only rearrange the order if the series'
content was ACKed in complete.

Moving removal of the workarounds to a later point in time won't
affect operation (just leaves the workaround in place a little
longer, while it does not harm), and will eliminate potential for
conflicts.  This I would do when accepting the series was
decided, to not lose the precious test feature during
development.

A byproduct of this rearrangement is that patches in phase 3
won't any longer touch a peripheral driver _and_ the clock driver
within a single patch, for whatever that may be worth.


So I suggest the following:

I can move parts 19 and 22 (completely) and the "workaround
removal" aspect of parts 20-21 and 23-28 to a later point in the
sequence, maybe squash them with part 31 (cleanup after migration
has completed).

This allows for even better (conflict free) application of the
series through individual and most appropriate trees.  All of
this of course assumes that the series passes review, and that
you agree on the outlined application in four phases if the
series cannot be kept together:
- clock API use cleanup for peripheral drivers, and device tree
  update to provide previously missing hardware information
- introduction of the platform clock driver and OF clock lookup
- adjustment of peripheral drivers after common clock support has
  become available
- removal of migration support and compat workarounds after
  migration has completed

Please consider that I'm not trying to be pushy :)  but that I
want to provide all the possible help and information on how the
series might get applied, assuming that it will pass review.  So
far there has not been objection, all feedback got addressed,
while explicit ACKs still are pending.

For your reference here is the stats and the (numbered) list of
files again:

0000-cover-letter.patch
0001-spi-mpc512x-cleanup-clock-API-use.patch
0002-serial-mpc512x-cleanup-clock-API-use.patch
0003-USB-fsl-mph-dr-of-cleanup-clock-API-use.patch
0004-mtd-mpc5121_nfc-cleanup-clock-API-use.patch
0005-media-fsl-viu-cleanup-clock-API-use.patch
0006-i2c-mpc-cleanup-clock-API-use.patch
0007-fs_enet-silence-a-build-warning-unused-variable.patch
0008-fs_enet-cleanup-clock-API-use.patch
0009-powerpc-fsl-pci-improve-clock-API-use.patch
0010-net-can-mscan-add-a-comment-on-reg-to-idx-mapping.patch
0011-net-can-mscan-improve-clock-API-use.patch
0012-powerpc-mpc512x-array-decl-for-MCLK-registers-in-CCM.patch
0013-clk-wrap-I-O-access-for-improved-portability.patch
0014-dts-mpc512x-prepare-for-preprocessor-support.patch
0015-dts-mpc512x-introduce-dt-bindings-clock-header.patch
0016-dts-mpc512x-add-clock-related-device-tree-specs.patch
0017-clk-mpc512x-introduce-COMMON_CLK-for-MPC512x.patch
0018-dts-mpc512x-add-clock-specs-for-client-lookups.patch
0019-clk-mpc512x-don-t-pre-enable-FEC-and-I2C-clocks.patch
0020-spi-mpc512x-switch-to-CCF-names-in-clock-lookup.patch
0021-serial-mpc512x-switch-to-CCF-names-in-clock-lookup.patch
0022-clk-mpc512x-remove-PSC-UART-SPI-compat-workarounds.patch
0023-serial-mpc512x-setup-the-PSC-FIFO-clock-as-well.patch
0024-USB-fsl-mph-dr-of-remove-now-obsolete-clock-lookup-n.patch
0025-mtd-mpc5121_nfc-remove-now-obsolete-clock-lookup-nam.patch
0026-media-fsl-viu-remove-now-obsolete-clock-lookup-name.patch
0027-net-can-mscan-add-common-clock-support-for-mpc512x.patch
0028-powerpc-mpc512x-improve-DIU-related-clock-setup.patch
0029-clk-mpc512x-switch-to-COMMON_CLK-remove-PPC_CLOCK.patch
0030-net-can-mscan-remove-non-CCF-code-for-MPC512x.patch
0031-clk-mpc512x-remove-remaining-migration-workarounds.patch

quoted

Gerhard Sittig (31):
  spi: mpc512x: cleanup clock API use
  serial: mpc512x: cleanup clock API use
  USB: fsl-mph-dr-of: cleanup clock API use
  mtd: mpc5121_nfc: cleanup clock API use
  [media] fsl-viu: cleanup clock API use
  i2c: mpc: cleanup clock API use
  fs_enet: silence a build warning (unused variable)
  fs_enet: cleanup clock API use
  powerpc/fsl-pci: improve clock API use
  net: can: mscan: add a comment on reg to idx mapping
  net: can: mscan: improve clock API use
  powerpc: mpc512x: array decl for MCLK registers in CCM
  clk: wrap I/O access for improved portability
  dts: mpc512x: prepare for preprocessor support
  dts: mpc512x: introduce dt-bindings/clock/ header
  dts: mpc512x: add clock related device tree specs
  clk: mpc512x: introduce COMMON_CLK for MPC512x
  dts: mpc512x: add clock specs for client lookups
  clk: mpc512x: don't pre-enable FEC and I2C clocks
  spi: mpc512x: switch to CCF names in clock lookup
  serial: mpc512x: switch to CCF names in clock lookup
  clk: mpc512x: remove PSC (UART, SPI) compat workarounds
  serial: mpc512x: setup the PSC FIFO clock as well
  USB: fsl-mph-dr-of: remove now obsolete clock lookup name
  mtd: mpc5121_nfc: remove now obsolete clock lookup name
  [media] fsl-viu: remove now obsolete clock lookup name
  net: can: mscan: add common clock support for mpc512x
  powerpc/mpc512x: improve DIU related clock setup
  clk: mpc512x: switch to COMMON_CLK, remove PPC_CLOCK
  net: can: mscan: remove non-CCF code for MPC512x
  clk: mpc512x: remove remaining migration workarounds

 arch/powerpc/boot/dts/ac14xx.dts                   |    9 +-
 arch/powerpc/boot/dts/include/dt-bindings          |    1 +
 arch/powerpc/boot/dts/mpc5121.dtsi                 |  110 ++-
 arch/powerpc/boot/dts/mpc5121ads.dts               |    2 +-
 arch/powerpc/boot/dts/pdm360ng.dts                 |    2 +-
 arch/powerpc/include/asm/mpc5121.h                 |   18 +-
 arch/powerpc/platforms/512x/Kconfig                |    2 +-
 arch/powerpc/platforms/512x/Makefile               |    3 +-
 arch/powerpc/platforms/512x/clock-commonclk.c      |  716 +++++++++++++++++++
 arch/powerpc/platforms/512x/clock.c                |  753 --------------------
 arch/powerpc/platforms/512x/mpc512x_shared.c       |  165 +++--
 arch/powerpc/sysdev/fsl_pci.c                      |   22 +
 drivers/clk/clk-divider.c                          |    6 +-
 drivers/clk/clk-gate.c                             |    6 +-
 drivers/clk/clk-mux.c                              |    6 +-
 drivers/i2c/busses/i2c-mpc.c                       |   24 +
 drivers/media/platform/fsl-viu.c                   |   23 +-
 drivers/mtd/nand/mpc5121_nfc.c                     |   21 +-
 drivers/net/can/mscan/mpc5xxx_can.c                |  281 +++++---
 drivers/net/can/mscan/mscan.c                      |   27 +-
 drivers/net/can/mscan/mscan.h                      |    3 +
 .../net/ethernet/freescale/fs_enet/fs_enet-main.c  |   21 +-
 drivers/spi/spi-mpc512x-psc.c                      |   60 +-
 drivers/tty/serial/mpc52xx_uart.c                  |  179 ++++-
 drivers/usb/host/fsl-mph-dr-of.c                   |   27 +-
 include/dt-bindings/clock/mpc512x-clock.h          |   69 ++
 include/linux/clk-provider.h                       |   33 +
 include/linux/fs_enet_pd.h                         |    3 +
 28 files changed, 1534 insertions(+), 1058 deletions(-)
 create mode 120000 arch/powerpc/boot/dts/include/dt-bindings
 create mode 100644 arch/powerpc/platforms/512x/clock-commonclk.c
 delete mode 100644 arch/powerpc/platforms/512x/clock.c
 create mode 100644 include/dt-bindings/clock/mpc512x-clock.h

virtually yours
Gerhard Sittig
-- 
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