Re: [PATCH] gpio: add trace events for setting direction and value

[Grant Likely]

On Wed, Feb 16, 2011 at 06:03:04PM +0100, Uwe Kleine-König wrote:
> This patch allows to trace gpio operations using ftrace
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>

Applied, thanks.

g.

> ---
> Hello,
> 
> two things that could be optimised later are:
> 
>  - combine gpio_direction_output into a single event?
>  - record _cansleep?
> 
> Best regards
> Uwe
> 
>  drivers/gpio/gpiolib.c      |   18 ++++++++++++-
>  include/trace/events/gpio.h |   56 +++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 72 insertions(+), 2 deletions(-)
>  create mode 100644 include/trace/events/gpio.h
> 
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index 649550e..5fc5e2d 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -12,6 +12,8 @@
>  #include <linux/idr.h>
>  #include <linux/slab.h>
>  
> +#define CREATE_TRACE_POINTS
> +#include <trace/events/gpio.h>
>  
>  /* Optional implementation infrastructure for GPIO interfaces.
>   *
> @@ -1404,6 +1406,8 @@ int gpio_direction_input(unsigned gpio)
>  	status = chip->direction_input(chip, gpio);
>  	if (status == 0)
>  		clear_bit(FLAG_IS_OUT, &desc->flags);
> +
> +	trace_gpio_direction(chip->base + gpio, 1, status);
>  lose:
>  	return status;
>  fail:
> @@ -1457,6 +1461,8 @@ int gpio_direction_output(unsigned gpio, int value)
>  	status = chip->direction_output(chip, gpio, value);
>  	if (status == 0)
>  		set_bit(FLAG_IS_OUT, &desc->flags);
> +	trace_gpio_value(chip->base + gpio, 0, value);
> +	trace_gpio_direction(chip->base + gpio, 0, status);
>  lose:
>  	return status;
>  fail:
> @@ -1546,10 +1552,13 @@ EXPORT_SYMBOL_GPL(gpio_set_debounce);
>  int __gpio_get_value(unsigned gpio)
>  {
>  	struct gpio_chip	*chip;
> +	int value;
>  
>  	chip = gpio_to_chip(gpio);
>  	WARN_ON(chip->can_sleep);
> -	return chip->get ? chip->get(chip, gpio - chip->base) : 0;
> +	value = chip->get ? chip->get(chip, gpio - chip->base) : 0;
> +	trace_gpio_value(gpio, 1, value);
> +	return value;
>  }
>  EXPORT_SYMBOL_GPL(__gpio_get_value);
>  
> @@ -1568,6 +1577,7 @@ void __gpio_set_value(unsigned gpio, int value)
>  
>  	chip = gpio_to_chip(gpio);
>  	WARN_ON(chip->can_sleep);
> +	trace_gpio_value(gpio, 0, value);
>  	chip->set(chip, gpio - chip->base, value);
>  }
>  EXPORT_SYMBOL_GPL(__gpio_set_value);
> @@ -1618,10 +1628,13 @@ EXPORT_SYMBOL_GPL(__gpio_to_irq);
>  int gpio_get_value_cansleep(unsigned gpio)
>  {
>  	struct gpio_chip	*chip;
> +	int value;
>  
>  	might_sleep_if(extra_checks);
>  	chip = gpio_to_chip(gpio);
> -	return chip->get ? chip->get(chip, gpio - chip->base) : 0;
> +	value = chip->get ? chip->get(chip, gpio - chip->base) : 0;
> +	trace_gpio_value(gpio, 1, value);
> +	return value;
>  }
>  EXPORT_SYMBOL_GPL(gpio_get_value_cansleep);
>  
> @@ -1631,6 +1644,7 @@ void gpio_set_value_cansleep(unsigned gpio, int value)
>  
>  	might_sleep_if(extra_checks);
>  	chip = gpio_to_chip(gpio);
> +	trace_gpio_value(gpio, 0, value);
>  	chip->set(chip, gpio - chip->base, value);
>  }
>  EXPORT_SYMBOL_GPL(gpio_set_value_cansleep);
> diff --git a/include/trace/events/gpio.h b/include/trace/events/gpio.h
> new file mode 100644
> index 0000000..927a8ad
> --- /dev/null
> +++ b/include/trace/events/gpio.h
> @@ -0,0 +1,56 @@
> +#undef TRACE_SYSTEM
> +#define TRACE_SYSTEM gpio
> +
> +#if !defined(_TRACE_GPIO_H) || defined(TRACE_HEADER_MULTI_READ)
> +#define _TRACE_GPIO_H
> +
> +#include <linux/tracepoint.h>
> +
> +TRACE_EVENT(gpio_direction,
> +
> +	TP_PROTO(unsigned gpio, int in, int err),
> +
> +	TP_ARGS(gpio, in, err),
> +
> +	TP_STRUCT__entry(
> +		__field(unsigned, gpio)
> +		__field(int, in)
> +		__field(int, err)
> +	),
> +
> +	TP_fast_assign(
> +		__entry->gpio = gpio;
> +		__entry->in = in;
> +		__entry->err = err;
> +	),
> +
> +	TP_printk("%u %3s (%d)", __entry->gpio,
> +		__entry->in ? "in" : "out", __entry->err)
> +);
> +
> +TRACE_EVENT(gpio_value,
> +
> +	TP_PROTO(unsigned gpio, int get, int value),
> +
> +	TP_ARGS(gpio, get, value),
> +
> +	TP_STRUCT__entry(
> +		__field(unsigned, gpio)
> +		__field(int, get)
> +		__field(int, value)
> +	),
> +
> +	TP_fast_assign(
> +		__entry->gpio = gpio;
> +		__entry->get = get;
> +		__entry->value = value;
> +	),
> +
> +	TP_printk("%u %3s %d", __entry->gpio,
> +		__entry->get ? "get" : "set", __entry->value)
> +);
> +
> +#endif /* if !defined(_TRACE_GPIO_H) || defined(TRACE_HEADER_MULTI_READ) */
> +
> +/* This part must be outside protection */
> +#include <trace/define_trace.h>
> -- 
> 1.7.2.3
> 
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