gpio: add trace events for setting direction and value
This patch allows to trace gpio operations using ftrace
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index c27e52b..137a8ca 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.
*
@@ -1405,6 +1407,8 @@
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:
@@ -1458,6 +1462,8 @@
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:
@@ -1547,10 +1553,13 @@
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);
@@ -1569,6 +1578,7 @@
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);
@@ -1619,10 +1629,13 @@
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);
@@ -1632,6 +1645,7 @@
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>