On Wed, 07 Aug 2013, Linus Walleij wrote:

On Tue, Jul 30, 2013 at 2:42 AM, Kim, Milo [off-list ref] wrote:

quoted

This is one of LP3943 MFD driver.
LP3943 is configurable as a GPIO expander, up to 16 GPIOs.

* Application note: how to configure LP3943 as a GPIO expander
  http://www.ti.com/lit/an/snva287a/snva287a.pdf

* Supported GPIO controller operations
  request, free, direction_input, direction_output, get and set

* GPIO direction register not supported
  LP3943 doesn't have the GPIO direction register. It only provides input and
  output status registers.
  So, private data for the direction should be handled manually.
  This variable is updated whenever the direction is changed and
  used in 'get' operation.

* Pin assignment
  A driver data, 'pin_used' is checked when a GPIO is requested.
  If the GPIO is already assigned, then returns as failure.
  If the GPIO is available, 'pin_used' is set.
  When the GPIO is not used anymore, then it is cleared.
  It is defined as unsigned long type for atomic bit operation APIs,
  but only LSB 16bits are used because LP3943 has 16 outputs.

Cc: Linus Walleij <redacted>
Signed-off-by: Milo Kim <redacted>
---
* Patch v2
  Use bitops macros for bit manipulations.
  Support device tree structure for the GPIO controller.
  Add request() and free() for the pin assignment.

This adresses all my concerns, nice driver.
Reviewed-by: Linus Walleij <redacted>

I guess this will be merged through the MFD tree along
with the MFD core patch? That needs to go in first anyway.

That's fine, but first:

1/4 Needs Linus to review
4/4 Needs Thierry's PWM Ack

After that please send v3 with Linus' Rev-By on this patch.

-- 
Lee Jones
Linaro ST-Ericsson Landing Team Lead
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