Re: [PATCH 1/2] pwm: Add __weak attributed functions for pwm operations

[Mohan Pallaka <mpallaka@codeaurora.org>]

On 3/7/2011 4:39 PM, Mohan Pallaka wrote:
> For chip drivers that support both pwm and non-pwm modes
> would encounter compilation errors if the platform doesn't
> have support for pwm though the chip is programmed to work
> in non-pwm mode. Add __weak attributed pwm functions to avoid
> compilation issues in these scenarios.
> 
> Signed-off-by: Mohan Pallaka <mpallaka@codeaurora.org>
> ---
>  include/linux/pwm.h |   21 ++++++++++++++++-----
>  1 files changed, 16 insertions(+), 5 deletions(-)
> 
> diff --git a/include/linux/pwm.h b/include/linux/pwm.h
> index 7c77575..3a8c3df 100644
> --- a/include/linux/pwm.h
> +++ b/include/linux/pwm.h
> @@ -3,29 +3,40 @@
>  
>  struct pwm_device;
>  
> +/* Add __weak functions to support PWM */
> +
>  /*
>   * pwm_request - request a PWM device
>   */
> -struct pwm_device *pwm_request(int pwm_id, const char *label);
> +struct pwm_device __weak *pwm_request(int pwm_id, const char *label)
> +{
> +	return NULL;
> +}
>  
>  /*
>   * pwm_free - free a PWM device
>   */
> -void pwm_free(struct pwm_device *pwm);
> +void __weak pwm_free(struct pwm_device *pwm) { }
>  
>  /*
>   * pwm_config - change a PWM device configuration
>   */
> -int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns);
> +int __weak pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
> +{
> +	return -ENODEV;
> +}
>  
>  /*
>   * pwm_enable - start a PWM output toggling
>   */
> -int pwm_enable(struct pwm_device *pwm);
> +int __weak pwm_enable(struct pwm_device *pwm)
> +{
> +	return -EINVAL;
> +}
>  
>  /*
>   * pwm_disable - stop a PWM output toggling
>   */
> -void pwm_disable(struct pwm_device *pwm);
> +void __weak pwm_disable(struct pwm_device *pwm) { }
>  
>  #endif /* __LINUX_PWM_H */
> 

Ping.

Please spend sometime to review this.

Thanks,
Mohan.

-- 
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.