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SubjectRe: [PATCH v2 7/7] ARM: davinci: Start using gpiolib API inplace of inline functions
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On Fri, Jun 14, 2013 at 11:35 AM, Philip Avinash <avinashphilip@ti.com> wrote:

> 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>
> ---
> Changes since v1:
> - Remove inline GPIO API support for tnetv107x platforms
> - Remove gpio header files in mach directory.
> - Remove include of gpio header files from mach directory.
> - Moved enum davinci_gpio_type to include folder
> - Replace __ASM_ARCH_DAVINCI_GPIO_H with __DAVINCI_GPIO_PLATFORM_H

Acked-by: Linus Walleij <linus.walleij@linaro.org>
on this as well, and this whole 7-patch series.

For sure things look better after this series than before it,
even if there may be details I think need to be adressed later.

Yours,
Linus Walleij


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