RE: [PATCH v3 00/11] common clk drivers migration for DaVinci SoCs

From: Karicheri, Muralidharan
Date: Tue Oct 30 2012 - 13:02:32 EST

Mike, Sekhar,

Could you please take some time to review this patch set? Last one was reviewed by Sekhar and I have re-worked the patch to address his comments.

Murali

>> -----Original Message-----
>> From: Karicheri, Muralidharan
>> Sent: Thursday, October 25, 2012 12:12 PM
>> To: mturquette@xxxxxxxxxx; arnd@xxxxxxxx; akpm@xxxxxxxxxxxxxxxxxxxx;
>> shawn.guo@xxxxxxxxxx; rob.herring@xxxxxxxxxxx; linus.walleij@xxxxxxxxxx;
>> viresh.linux@xxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Nori, Sekhar; Hilman, Kevin;
>> linux@xxxxxxxxxxxxxxxx; sshtylyov@xxxxxxxxxx; davinci-linux-open-
>> source@xxxxxxxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
>> Cc: linux-keystone@xxxxxxxxxxx - Linux developers for Keystone family of devices (May
>> contain non-TIers); Karicheri, Muralidharan
>> Subject: [PATCH v3 00/11] common clk drivers migration for DaVinci SoCs
>>
>> This is v3 of the patch series for implementing clock tree for DaVinci SoCs using common
>> clk framework.
>>
>> supported platforms: DM644x
>>
>> This code base can be accessed at
>>
>> https://gitorious.org/~m-karicheri/linux-davinci/linux-davinci-clk/commits/common-clk-
>> v3
>>
>> The patch series is split in two parts:-
>> patches prefixed with "clk" are for clk drivers
>> patches prefixed with "ARM" are for davinci machine specific code.
>>
>> revision history:
>> -----------------
>> updates in v3:
>> - Major changes done based on review of v2 to move the clock data and
>> initialization code to drivers/clk/davinci. There is a soc specific
>> code (for example dm644x-clock.c) for doing clock initialization.
>> - Files renamed based on the review comments.
>> - Only DM644x is supported. Other devices will be added as the code
>> matures so that unnecessary rework can be avoided.
>> - Incorporated comments from Nori Sekhar and Linus (comments coding
>> style)
>> - Added clk-div clock to represent DaVinci pll divider clocks
>> - Removed clk-keystone-pll.c (will be added later)
>>
>> updates in v2:
>> - updates to davinci_clk to use union for clk driver platform data
>> - Fixed Linus Walleij' comment on code comment
>> - added code clean up that takes out the ifdef used in previous patches
>>
>> updates in v1:
>> - Added DM365 and DM355
>> - updates to davinci_clk struct to accomodate clk-fixed-factor data
>>
>> initial version:-
>>
>> Currently arch/arm/mach-davinci/clock.c and arch/arm/mach-davinci/psc.c implements
>> clock drivers for DaVinci. This patch makes these code obsolete and migrate the SoC code
>> to use the common clk based drivers. This adds two clk drivers specific to DaVinci and
>> Keystone (found in c6x arch such as C6678) devices. Some of the existing clk drivers such
>> as clk-fixed-rate, clk-divider, and clk-mux are re-used in addition to the DaVinci specific
>> drivers to initialize the clock tree for the SoCs. Please refer chapter 6 of
>> http://www.ti.com/lit/ug/sprue14c/sprue14c.pdf for details of the PLL hardware in
>> DM6446 and chapter 7 for defails of the PSC hardware.
>>
>> There are two Main PLLs in DM644x. PLL1 and PLL2. Each of these generate different
>> clocks in the DM device through PLL dividers. Figure above shows this for PLL1. Similar
>> hardware exists for PLL2 and the related output clocks. The hardware is similar in most of
>> the DM SoCs. Some of the recent Keystone devices
>> (c6678 under c6x architecture) include a slight variant of the PLL that implemented
>> different registers for the multipliers and dividers. All of these devices include PLL dividers
>> (PLLDIVx) and Power Sleep controllers (PSC). The SoCs defines various Power Domains
>> and Clock domains and there are PSC modules that controls power and clocks to various
>> hardware IPs of the SoC.
>>
>> Following drivers are used for various clock hardware blocks:-
>>
>> CLKIN and OSCIN - clk-fixed-rate (existing driver) MUX - clk-mux (existing driver)
>> PLLDIVx - davinci/clk-div (new driver) PLL mult/div - clk-pll (new driver) PSC - clk-psc.c
>> (new driver)
>>
>> Please note that initially only platforms listed above are supported. The idea is to review
>> the initial patch set and get a feedback on the overall structure of the code organization.
>> The other SoCs will be added in subsequent patch revisions.
>>
>> The driver code implements the features needed to support the platforms listed above. It
>> is expected that these drivers get updated in subsequent patch revisions to support
>> additional SoCs. I have boot tested this on DM6446 EVM. Also verified reboot command
>> works and the clock rates are set as before.
>> The patches depends on the following patches that I had sent for review earlier:
>>
>> davinci spi driver preparation @
>> https://patchwork.kernel.org/patch/1389321/
>> davinci watchdog driver preparation @
>> https://lkml.org/lkml/2012/9/7/634
>> davinci nand driver preparation @
>> https://lkml.org/lkml/2012/9/7/635
>> davinci i2c driver preparation @
>> https://patchwork.kernel.org/patch/1388841/
>> davinci gpio driver preparation @
>> https://lkml.org/lkml/2012/8/31/341
>>
>> [RFC - PATCH] base:pm: prepare driver for common clock framework
>>
>> ISSUES to discuss
>> -----------------
>> Following are to be discussed as part of this patch review.
>>
>> 1. arch/arm/pm.c. This is configuring PLL controller registers for suspend and
>> resume. It appears that we need to move this code to clk-pll.c?? But
>> I can't find APIs for suspend and resume in the common clk framework. How
>> is this expected to work? Currently i have kept the code ASIS.
>>
>> 2. There are usecount=1 in the old clock implementation for dsp, vicp and timer2
>> clocks. CLK_IGNORE_UNUSED flag is used currently to implement the same as
>> disabling these unused clocks causes issues in boot up,
>>
>> HELP NEEDED!!:
>> --------------
>> I am doing this work as a background activity and hence the progress will be slow. Please
>> volunteer to help me in this effort by offering to test or migrating other devices to this
>> framework.
>>
>> Murali Karicheri (11):
>> clk: davinci - add main PLL clock driver
>> clk: davinci - add PSC clock driver
>> clk: davinci - common clk utilities to init clk driver
>> clk: davinci - add pll divider clock driver
>> clk: davinci - add dm644x clock initialization
>> clk: davinci - add build infrastructure for DaVinci clock drivers
>> ARM: davinci - restructure header files for common clock migration
>> ARM: davinci - migrating to use common clock init code
>> ARM: davinci - dm644x: update SoC code to remove the clock data
>> ARM: davinci - migrate to common clock
>> ARM: davinci - common clock migration: clean up the old code
>>
>> arch/arm/Kconfig | 1 +
>> arch/arm/mach-davinci/Kconfig | 2 +
>> arch/arm/mach-davinci/Makefile | 15 +-
>> arch/arm/mach-davinci/clock.c | 669 ---------------------------
>> arch/arm/mach-davinci/clock.h | 135 ------
>> arch/arm/mach-davinci/common.c | 10 -
>> arch/arm/mach-davinci/cpufreq.c | 2 -
>> arch/arm/mach-davinci/davinci.h | 3 +
>> arch/arm/mach-davinci/devices.c | 1 -
>> arch/arm/mach-davinci/dm644x.c | 302 +-----------
>> arch/arm/mach-davinci/include/mach/clock.h | 21 -
>> arch/arm/mach-davinci/include/mach/common.h | 10 +-
>> arch/arm/mach-davinci/include/mach/pll.h | 46 ++
>> arch/arm/mach-davinci/include/mach/psc.h | 209 ---------
>> arch/arm/mach-davinci/include/mach/time.h | 2 +-
>> arch/arm/mach-davinci/pm.c | 3 +-
>> arch/arm/mach-davinci/psc.c | 112 -----
>> arch/arm/mach-davinci/sleep.S | 3 +-
>> arch/arm/mach-davinci/time.c | 6 +-
>> drivers/clk/Kconfig | 2 +
>> drivers/clk/Makefile | 1 +
>> drivers/clk/davinci/Kconfig | 44 ++
>> drivers/clk/davinci/Makefile | 5 +
>> drivers/clk/davinci/clk-div.c | 124 +++++
>> drivers/clk/davinci/clk-div.h | 42 ++
>> drivers/clk/davinci/clk-pll.c | 146 ++++++
>> drivers/clk/davinci/clk-pll.h | 57 +++
>> drivers/clk/davinci/clk-psc.c | 207 +++++++++
>> drivers/clk/davinci/clk-psc.h | 46 ++
>> drivers/clk/davinci/clock.c | 112 +++++
>> drivers/clk/davinci/clock.h | 80 ++++
>> drivers/clk/davinci/dm644x-clock.c | 304 ++++++++++++
>> drivers/clk/davinci/pll.h | 83 ++++
>> drivers/clk/davinci/psc.h | 215 +++++++++
>> 34 files changed, 1530 insertions(+), 1490 deletions(-) delete mode 100644
>> arch/arm/mach-davinci/clock.c delete mode 100644 arch/arm/mach-davinci/clock.h
>> delete mode 100644 arch/arm/mach-davinci/include/mach/clock.h
>> create mode 100644 arch/arm/mach-davinci/include/mach/pll.h
>> delete mode 100644 arch/arm/mach-davinci/psc.c create mode 100644
>> drivers/clk/davinci/Kconfig create mode 100644 drivers/clk/davinci/Makefile create
>> mode 100644 drivers/clk/davinci/clk-div.c create mode 100644 drivers/clk/davinci/clk-
>> div.h create mode 100644 drivers/clk/davinci/clk-pll.c create mode 100644
>> drivers/clk/davinci/clk-pll.h create mode 100644 drivers/clk/davinci/clk-psc.c create
>> mode 100644 drivers/clk/davinci/clk-psc.h create mode 100644
>> drivers/clk/davinci/clock.c create mode 100644 drivers/clk/davinci/clock.h create mode
>> 100644 drivers/clk/davinci/dm644x-clock.c
>> create mode 100644 drivers/clk/davinci/pll.h create mode 100644
>> drivers/clk/davinci/psc.h
>>
>> --
>> 1.7.9.5

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