gpio: davinci: move to platform device

Modify GPIO Davinci driver to be compliant to standard platform drivers.
The driver did not have platform driver structure or a probe. Instead,
had a davinci_gpio_setup() function which is called in the pure_init
sequence. The function also had dependency on davinci_soc_info structure
of the corresponding platform. For Device Tree(DT) implementation, we
need to get rid of the dependency on the davinci_soc_info structure.
Hence as a first stage of DT conversion, we implement a probe. Future
commits shall modify the probe to read platform related data from DT.

- Add platform_driver structure and driver register function for davinci
  GPIO driver. The driver registration is made to happen in
  postcore_initcall. This is required since machine init functions like
  da850_lcd_hw_init() make use of GPIO.
- Convert the davinci_gpio_setup() to davinci_gpio_probe().
- Remove access of members in soc_info structure. Instead, relevant data
  are taken from davinci_gpio_platform_data structure pointed by
  pdev->dev.platform_data.
- Change clk_get() to devm_clk_get() as devm_clk_get() is a device
  managed function and makes error handling simpler.
- Change pr_err to dev_err for ngpio error reporting.
- Arrange include files in alphabetical order

Signed-off-by: KV Sujith <sujithkv@ti.com>
[avinashphilip@ti.com: Move global definition for "struct
davinci_gpio_controller" variable to local in probe and set it as driver
data.]
Signed-off-by: Philip Avinash <avinashphilip@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
ARM: davinci: da8xx: creation of gpio platform device

gpio controller resource information being associated with
davinci_soc_info structure and not created any device. Hence davinci
gpio didn't fall under proper device model. This patch creates gpio
davinci as a platform device for da8xx platforms.

- Add Memory and IRQ resources for da8xx
- Register GPIO platform driver for da8xx.
- Add da8xx_register_gpio API to create platform device for da8xx
  platforms.

Signed-off-by: KV Sujith <sujithkv@ti.com>
Signed-off-by: Philip Avinash <avinashphilip@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
ARM: davinci: creation of gpio platform device for dmxxx platforms

gpio controller resource information being associated with
davinci_soc_info structure and not created any device. Hence davinci
gpio didn't fall under proper device model. This patch creates gpio
davinci as a platform device for dmxxx platforms.
Also add daivinci_register_gpio API to create platform device for dmxxx
platforms.

Signed-off-by: Philip Avinash <avinashphilip@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
ARM: davinci: da8xx: gpio device creation

Create davinci gpio device and remove references in davinci_soc_info
structure. Also rearrange header file inclusion in group basis.

Signed-off-by: Philip Avinash <avinashphilip@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
ARM: davinci: dmxxx: gpio device creation

Create davinci gpio device and remove gpio references in
davinci_soc_info structure for dmxxx platforms. Also add Memory and IRQ
resources for GPIO platform device.

Signed-off-by: Philip Avinash <avinashphilip@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
ARM: davinci: Start using gpiolib API inplace of inline functions

Remove NEED_MACH_GPIO_H config select option for ARCH_DAVINCI to start
use gpiolib interface for davinci platforms. However with this software
latencies for gpio_get/set APIs will affect. Latency has increased by 18
microsecond with gpiolib API as compared with inline API's.

Software latency is calculated on da850 EVM for gpio_get_value API by
taking the printk timing for API execution with interrupts disabled.
Experiment has done for inline and gpiolib API interface.

  inline gpio API with interrupt disabled
  [   29.734337] before gpio_get
  [   29.736847] after gpio_get

  Time difference 0.00251

  gpio library with interrupt disabled
  [  272.876763] before gpio_get
  [  272.879291] after gpio_get

  Time difference 0.002528
  Latency increased by (0.002528 -  0.00251) = 18 microsecond.

Also being here
- Moved following definitions from mach folder to include directory
	struct davinci_gpio_controller
	Macro GPIO(x)
	inline function __gpio_mask
- Removed GPIO_TYPE_DAVINCI enum definition as GPIO Davinci is converted
  to Linux device driver model.
- With removal of select option of NEED_MACH_GPIO_H for ARCH_DAVINCI,
  gpio-tnetv107x also start using gpiolib interface. Hence removes
  related header files
	arch/arm/mach-davinci/include/mach/gpio-davinci.h
	arch/arm/mach-davinci/include/mach/gpio.h

  and include linux/platform_data/gpio-davinci.h header file to support
  gpio-davinci platform definitions.

Signed-off-by: Philip Avinash <avinashphilip@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
ARM: davinci: da850: Use #include for all device trees

Replace /include/ by #include for da850 device tree files, in order to
use the C pre-processor, making use of #define features possible.

Signed-off-by: Philip Avinash <avinashphilip@ti.com>
gpio: davinci: DT changes for driver

- Add of_device_id for Davinci GPIO driver.
- Add function to populate data from DT.
- Modify the probe to read from DT if DT match is found.
- Add DT binding documentation for Davinci GPIO properties in a new file
  gpio-davinci.txt located at Documentation/devicetree/bindings/gpio/.

Signed-off-by: KV Sujith <sujithkv@ti.com>
Signed-off-by: Philip Avinash <avinashphilip@ti.com>
ARM: davinci: da850: add GPIO DT entries

Add DT entries for Davinci GPIO.

Signed-off-by: KV Sujith <sujithkv@ti.com>
Signed-off-by: Philip Avinash <avinashphilip@ti.com>
ARM: davinci: da850 evm: add GPIO DT data

- Add GPIO DT Data and pinmux for DA850 EVM. GPIO is configurable differently
  on different boards. So add GPIO pinmuxing in dts file.
- Dependency: This patch is dependent on Grab-pin-control patch;
  https://patchwork.kernel.org/patch/2013751/

Signed-off-by: KV Sujith <sujithkv@ti.com>
Signed-off-by: Philip Avinash <avinashphilip@ti.com>