[PATCH v9 00/31] gpio/omap: driver cleanup and fixes

Tarun Kanti DebBarma tarun.kanti at ti.com
Tue Dec 13 15:20:02 EST 2011

This series is continuation of cleanup of OMAP GPIO driver and fixes.
The cleanup include getting rid of cpu_is_* checks wherever possible,
use of gpio_bank list instead of static array, use of unique platform
specific value associated data member to OMAP platforms to avoid
cpu_is_* checks. The series also include PM runtime support.

Baseline: git://github.com/khilman/linux-omap-pm.git
Branch: for_3.3/gpio-base

Baseline: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
Branch: master
Commit: b835c0f

Power Tests
a) OMAP3430SDP
- Modify board-3430sdp.c file to have multiple GPIO modules active
  with debounce timeout enabled.
- Enable CPU-Idle
- Enable UART timeouts
- Enable offmode
- echo mem > /sys/power/state
- Verify retention and offmode count increment

b) ZOOM3
- Enable CPU-Idle
- Enable UART timeout
- echo mem > /sys/power/state
- Wakeup system using serial keyboard
- Verify retention count increment

Functional Tests
- Done on OMAP2430, OMAP3430SDP, ZOOM3, OMAP4430

Bootup Test
- Done on OMAP1710

- Summary of Comments/Issues fixed
  * GPIO wakeup does not work
  * Call debounce clock enable/disable functions from PM runtime callbacks.
    This will avoid calling the functions from multiple places.
  * Modify description of following patch to match latest changes.
    gpio/omap: save and restore debounce registers
  * Use (bank->regs->set_dataout && bank->regs->clr_dataout) together instead
    of using only one of them.  
  * Remove cpu_is_omapxxxx() checks from set_gpio_trigger().
  * _gpio_dbck_enable() in runtime callback triggered from omap_gpio_request
    does not enable dbck because dbck_enable_mask is not set at this point.
  * Workaround associated with an errata got missed in v8. This has been
- Added following new patches
  * gpio/omap: get rid of saved_fallingdetect, saved_risingdetect
  * gpio/omap: remove retrigger variable in gpio_irq_handler
  * gpio/omap: fix _set_gpio_irqenable implementation
  * gpio/omap: fix trigger type to unsigned
  * gpio/omap: remove saved_wakeup field from struct gpio_bank
- Remove PM_CONFIG macro around following assignment.
  pdata->get_context_loss_count = omap_pm_get_dev_context_loss_count;

- Once pm_runtime is enabled there is no more need for calling the

- With pm_runtime, handling of clocks in Suspend is  taken care of by
  powerdomain hooks. So remove usage of *_runtime_put/get* from
  suspend/resume hooks and Idle path.

- Add handling of debounce clocks along the Suspend and Idle paths.

- Remove [PATCH 04/24] gpio/omap: fix pwrdm_post_transition call sequence
  from this series. This will be merged as part of power cleanup series.

- Remove [PATCH v7 20/26] gpio/omap: skip operations in runtime callbacks
  The bank->mod_usage check in this patch is not needed any more because
  they are now already being taken care in suspend/resume and Idle paths.

- Remove [PATCH v7 26/26] gpio/omap: add dbclk aliases for all gpio modules
  This is already taken care in hwmod.

- Remove redundant blank line in
  [PATCH v7 14/26] gpio/omap: remove unnecessary bit-masking for read access

-               if (cpu_is_omap15xx() && (bank->method == METHOD_MPUIO))
-                       isr &= 0x0000ffff;

               if (bank->level_mask)
                       level_mask = bank->level_mask & enabled;

- Use pm_runtime_put() instead of pm_runtime_put_sync_suspend()
- Keep *_runtime_get/put*()  outside spinlock
- Remove additional checking of conditions in _restore_context()
 if (bank->regs->set_dataout && bank->regs->clear_dataout)
 if (bank->regs->set_dataout)

- In [PATCH 19/25] gpio/omap: cleanup prepare_for_idle and resume_after_idle,
  protect the bank data elements and register access using spinlock in
  runtime_suspend/resume() callbacks.
  This is because these callbacks run with interrupts enabled.
- Add dbclk aliases for all GPIO modules. Without this, GPIO modules were not
  getting the correct clock handle to enable/disable debounec clock.
- Fix log comments on the following patches:
  [PATCH 19/25] gpio/omap: cleanup prepare_for_idle and resume_after_idle
  [PATCH 20/25] gpio/omap: skip operations in runtime callbacks
  [PATCH 24/25] gpio/omap: restore OE only after setting the output level

- Save and restore debounce registers for proper driver operation.
- Restore interrupt enable after all configuration to avoid spurious interrupts.
- Restore dataout register before oe register.
- Restore dataout into dataout_set or dataout based upon the OMAP version.
- Change register name from wkup_status to wkup_en.
- Remove wrapper around omap_pm_get_dev_context_loss_count(). Use it directly.
  Also, changed the signature of get_context_loss_count in pdata and bank structure
  from int to u32.

- Use 'context' instead of 'ctx' for clarity wherever it is used.
- Merged two patches into one which are related to bank_is_mpuio() modification.
- Use shift operator instead of following:
+       .irqctrl        = OMAP_MPUIO_GPIO_INT_EDGE / 2,

- Remove redundant check from the following
+       if (bank_is_mpuio(bank)) {
+               if (bank->regs->wkup_status) <--- redundant check
+                       mpuio_init(bank);

- Change subject of following patch
  [PATCH v5 15/22] gpio/omap: use readl in irq_handler for all access
  [PATCH 14/25] gpio/omap: remove unnecessary bit-masking for read access

- Fix multi-line comments in
  [PATCH v5 20/22] gpio/omap: cleanup prepare_for_idle and resume_after_idle

- Reduce runtime callback overhead when *_get/put_sync() called from probe()
  and *_gpio_request/free().

- Dynamic context save within functions where context is modified instead of
  saving all context within a common function.

- Removed call to mpuio_init() from omap_gpio_mod_init(). Both the functions are
  called once during initialization in *_gpio_probe().
  Call to omap_gpio_mod_init() has been removed from omap_gpio_request() on the
  first access to gpio bank. One time initialization looks sufficient.

- In *_gpio_irq_handler() use *_put_sync_suspend() instead of *_put_sync().

- Removed hardcoding of OMAP16xx sysconfig register value and instead defined an
  associated constant.

- Removed *_get_sync() call from *_gpio_suspend() and *_put_sync() call from
 *_gpio_resume(). They got wrongly slipped into the code.

- Removed following redundant zero allocated initialization from mach-omap2/gpio.c
+       pdata->regs->irqctrl = 0;
+       pdata->regs->edgectrl1 = 0;
+       pdata->regs->edgectrl2 = 0;

- Removed following redundant code in gpio-omap.c
 -#define bank_is_mpuio(bank)  ((bank)->method == METHOD_MPUIO)

- since all accesses to registers are 4-byte aligned, removing special
  checks and handling of 16 and 32-bit wide bank registers and instead
  use 32-bit read/write access consistently.

- redundant usage of MOD_REG_BIT has been corrected and replaced with

- omap_gpio_mod_init() function has been simplified further using _gpio_rmw().

- sysconfig register offset specific to omap16xx has been removed along
  with its usage.

- additional logic to skip from suspend/resume:

 if (!bank->regs->wkup_status || !bank->suspend_wakeup)
       return 0;

 if (!bank->regs->wkup_status || !bank->saved_wakeup)
       return 0;

- separated mpuio related changes into a different patch from the patch where
  wakeup status register related changes are done.

- Incorrect replacement of !cpu_class_is_omap2() in gpio_irq_type()
+       if (!bank->regs->leveldetect0 &&
+               (type & (IRQ_TYPE_LEVEL_LOW|IRQ_TYPE_LEVEL_HIGH)))
               return -EINVAL;

- Avoid use of wkup_set and wkup_clear registers. Instead use wkup_status
  register for all platforms. This is because on OMAP4 it is recommended
  not to use them.

- Remove duplicate code in omap_gpio_mod_init() for handling the same for
  32-bit and 16-bit GPIO bank widths. This is accomplished by having two
  functions to handle each case while assiging a common function pointer
  during initialization.

- Remove OMAP16xx specific one time initialization from omap_gpio_mod_init().
  Move it inside omap16xx_gpio_init().

- Avoid usage of USHRT_MAX to indicate undefined values. Use 0 instead.

- In omap_gpio_suspend()/resume() functions remove code that checks
  if the feature is supported. Instead, assign these functions to
  struct platform_driver's suspend & resume function pointers for those
  OMAP platforms whcih support this feature.

- Remove 'suspend_support' flag because it is redundant. Instead use
  wkup_* registers to decode the same information.

- Restore context also when we don't know if the context is lost.

- Make omap_gpio_save_context() and omap_gpio_restore_context() static.

- Do special handling of non-wakeup GPIOs only on OMAP2420. Avoid this
  handling on OMAP3430.
- Isolate cleanups and fixes into separate set of patches. Keep the cleanup
  first followed by the fixes.
- Avoid calling omap_gpio_get_context_loss() directly and instead call it
  through function pointer in pdata initialized during init.
- workaround_enabled flag is not longer needed and is removed.
- Call pwrdm_post_transition() before calling omap_gpio_resume_after_idle().
- In omap2_gpio_resume_after_idle() do context restore before handling
- Use PM runtime framework.
- Modify register offset names to : wkup_status, wkup_clear, wkup_set.
  Also use 'base + offset' for readibility in all relevant places.
- Remove unwanted messages from commit section like TODO, etc.

Charulatha V (8):
  gpio/omap: remove dependency on gpio_bank_count
  gpio/omap: use flag to identify wakeup domain
  gpio/omap: make gpio_context part of gpio_bank structure
  gpio/omap: make non-wakeup GPIO part of pdata
  gpio/omap: avoid cpu checks during module ena/disable
  gpio/omap: use pinctrl offset instead of macro
  gpio/omap: remove bank->method & METHOD_* macros
  gpio/omap: fix bankwidth for OMAP7xx MPUIO

Nishanth Menon (4):
  gpio/omap: save and restore debounce registers
  gpio/omap: enable irq at the end of all configuration in restore
  gpio/omap: restore OE only after setting the output level
  gpio/omap: handle set_dataout reg capable IP on restore

Tarun Kanti DebBarma (19):
  gpio/omap: handle save/restore context in GPIO driver
  gpio/omap: further cleanup using wkup_en register
  gpio/omap: use level/edge detect reg offsets
  gpio/omap: remove hardcoded offsets in context save/restore
  gpio/omap: cleanup set_gpio_triggering function
  gpio/omap: cleanup omap_gpio_mod_init function
  gpio/omap: remove unnecessary bit-masking for read access
  gpio/omap: use pm-runtime framework
  gpio/omap: optimize suspend and resume functions
  gpio/omap: cleanup prepare_for_idle and resume_after_idle
  gpio/omap: fix debounce clock handling
  gpio/omap: fix incorrect access of debounce module
  gpio/omap: remove omap_gpio_save_context overhead
  gpio/omap: edge trigger configuration for all non-wakeup gpios
  gpio/omap: get rid of saved_fallingdetect, saved_risingdetect
  gpio/omap: remove retrigger variable in gpio_irq_handler
  gpio/omap: fix _set_gpio_irqenable implementation
  gpio/omap: fix trigger type to unsigned
  gpio/omap: remove saved_wakeup field from struct gpio_bank

 arch/arm/mach-omap1/gpio15xx.c         |    7 +-
 arch/arm/mach-omap1/gpio16xx.c         |   47 ++-
 arch/arm/mach-omap1/gpio7xx.c          |   14 +-
 arch/arm/mach-omap2/gpio.c             |   36 +-
 arch/arm/mach-omap2/pm34xx.c           |   14 -
 arch/arm/plat-omap/include/plat/gpio.h |   29 +-
 drivers/gpio/gpio-omap.c               | 1146 ++++++++++++++------------------
 7 files changed, 586 insertions(+), 707 deletions(-)

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