Re: [PATCH v8 0/6] OMAP: WDT: Implement WDT in hwmod way

[Kevin Hilman <khilman@deeprootsystems.com>]

Hi Charu,

"Varadarajan, Charulatha" <charu@ti.com> writes:

> Series of patches to port watchdog module to use hwmod APIs
> for OMAP2PLUS chips and use runtime APIs for all OMAP chips.
> For this hwmod database for OMAP2PLUS watchdog instances are
> populated and implements watchdog module to use PM runtime APIs.
>
> This patch series is generated on "origin/pm-core" which
> has Kevin's pm-next series, the runtime PM core patch series,
> and a collection of hwmod fixes that Paul/Benoit have lined up
> for 2.6.37.
>
> Tested on OMAP2430, OMAP4430 (ES1.0 & ES2.0), OMAP3430 SDP boards
> and zoom3 board. Also verified that this patch series does not
> break the OMAP1 build.

I found a little snag with this series.  Try testing with
omap2plus_defconfig and changing CONFIG_OMAP_WATCHDOG=n.

If CONFIG_OMAP_WATCHDOG is not enabled in the kernel config, the system
will reboot soon after bootup.  One of the things the bootloader
historically has done was disable the watchdog so a driver wasn't needed.
With a reset of the IP triggered by the hwmod init, we lose this setting
and the watchog is armed by default.

I think we need to handle this case when CONFIG_OMAP_WATCHDOG=n in the
device init code by disabling the watchdog.

Kevin


> This series is tested on OMAP4430 ES2 using the below series
> (dependency series for ES2.0 silicon)
> http://www.spinics.net/lists/linux-omap/msg36023.html
>
> Version History:
> ---------------
> Version v8:
> *Enable wd_timer3 in the hwmod list
>
> Version v7:
> *Use EN_*SHIFT macros for module_bit and ST_*SHIFT macros for
> idlest_idle_bit in OMAP2&3 hwmod database
> (based on suggestions given by Paul for I2C hwmod series)
> *Remove new definitions of EN_*SHIFT macros as they already exist
> Some of the v7 links:
> https://patchwork.kernel.org/patch/197022/
>
> Version v6:
> *Split omap_init_wdt() into separate omap_init_wdt functions
> under mach-omap1 and mach-omap2 and set them up with
> subsys_initcall
> *Include wd_timer3 database for OMAP4
> *In hwmod database follow naming convention "wd_timerX"
> Some of the v6 links:
> http://www.spinics.net/lists/linux-omap/msg36678.html
> https://patchwork.kernel.org/patch/188242/
> https://patchwork.kernel.org/patch/188222/
>
> Version v5:
> *Delete wdt_runtime_resume and wdt_runtime_suspend
> functions as the fix for the return values in the generic
> runtime PM calls has been queued for 2.6.37 (see below link)
> https://lists.linux-foundation.org/pipermail/linux-pm/2010-September/028466.html
> Some of the v5 links:
> https://patchwork.kernel.org/patch/181812/
> https://patchwork.kernel.org/patch/181782/
> https://patchwork.kernel.org/patch/181772/
> https://patchwork.kernel.org/patch/181792/
>
> Version v4:
> *Implement hwmod adapdation first and then PM runtime adaptation
> as two different patches in the series
> *Remove inclusion of omap_device.h in the driver file.
> Some of the v4 links:
> https://patchwork.kernel.org/patch/174672/
> https://patchwork.kernel.org/patch/174662/
>
> Version v3:
> *Fix Minor comments like renaming omap1 watchdog structures
> with an omap1_ prefix
> Some of the v3 links:
> https://patchwork.kernel.org/patch/119698/
> https://patchwork.kernel.org/patch/119696/ 
>
> Version v2:
> *Rebase to latest kernel
> Some of the v2 links:
> http://www.spinics.net/lists/linux-omap/msg34741.html
> http://www.spinics.net/lists/linux-omap/msg34673.html
>
> Version v1:
> *Initial series
> Some of the v1 links:
> http://www.spinics.net/lists/linux-omap/msg30628.html
> http://www.spinics.net/lists/linux-omap/msg30625.html
>
> Benoit Cousson (1):
>   OMAP4: hwmod data: Add watchdog timer
>
> Varadarajan, Charulatha (5):
>   OMAP3: hwmod data: Add watchdog timer
>   OMAP2420: hwmod data: Add watchdog timer
>   OMAP2430: hwmod data: Add watchdog timer
>   OMAP2PLUS: WDT: use omap_device_build for device registration
>   OMAP: WDT: Use PM runtime APIs instead of clk FW APIs
>
>  arch/arm/mach-omap1/devices.c              |   27 ++++++
>  arch/arm/mach-omap2/devices.c              |   39 ++++++++
>  arch/arm/mach-omap2/omap_hwmod_2420_data.c |   64 +++++++++++++
>  arch/arm/mach-omap2/omap_hwmod_2430_data.c |   64 +++++++++++++
>  arch/arm/mach-omap2/omap_hwmod_3xxx_data.c |   66 ++++++++++++++
>  arch/arm/mach-omap2/omap_hwmod_44xx_data.c |  135 ++++++++++++++++++++++++++++
>  arch/arm/plat-omap/devices.c               |   41 ---------
>  drivers/watchdog/omap_wdt.c                |   42 ++-------
>  8 files changed, 402 insertions(+), 76 deletions(-)