regmap: Add basic tracepoints
Trace single register reads and writes, plus start/stop tracepoints for
the actual I/O to see where we're spending time. This makes it easy to
have always on logging without overwhelming the logs and also lets us take
advantage of all the context and time information that the trace subsystem
collects for us.
We don't currently trace register values for bulk operations as this would
add complexity and overhead parsing the cooked data that's being worked
with.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 02ed154..7d4dc11 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -17,6 +17,9 @@
#include <linux/regmap.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/regmap.h>
+
struct regmap;
struct regmap_format {
@@ -211,6 +214,9 @@
map->format.format_reg(map->work_buf, reg);
+ trace_regmap_hw_write_start(map->dev, reg,
+ val_len / map->format.val_bytes);
+
/* If we're doing a single register write we can probably just
* send the work_buf directly, otherwise try to do a gather
* write.
@@ -237,19 +243,31 @@
kfree(buf);
}
+ trace_regmap_hw_write_done(map->dev, reg,
+ val_len / map->format.val_bytes);
+
return ret;
}
static int _regmap_write(struct regmap *map, unsigned int reg,
unsigned int val)
{
+ int ret;
BUG_ON(!map->format.format_write && !map->format.format_val);
+ trace_regmap_reg_write(map->dev, reg, val);
+
if (map->format.format_write) {
map->format.format_write(map, reg, val);
- return map->bus->write(map->dev, map->work_buf,
- map->format.buf_size);
+ trace_regmap_hw_write_start(map->dev, reg, 1);
+
+ ret = map->bus->write(map->dev, map->work_buf,
+ map->format.buf_size);
+
+ trace_regmap_hw_write_done(map->dev, reg, 1);
+
+ return ret;
} else {
map->format.format_val(map->work_buf + map->format.reg_bytes,
val);
@@ -331,12 +349,16 @@
if (map->bus->read_flag_mask)
u8[0] |= map->bus->read_flag_mask;
+ trace_regmap_hw_read_start(map->dev, reg,
+ val_len / map->format.val_bytes);
+
ret = map->bus->read(map->dev, map->work_buf, map->format.reg_bytes,
val, val_len);
- if (ret != 0)
- return ret;
- return 0;
+ trace_regmap_hw_read_done(map->dev, reg,
+ val_len / map->format.val_bytes);
+
+ return ret;
}
static int _regmap_read(struct regmap *map, unsigned int reg,
@@ -348,8 +370,10 @@
return -EINVAL;
ret = _regmap_raw_read(map, reg, map->work_buf, map->format.val_bytes);
- if (ret == 0)
+ if (ret == 0) {
*val = map->format.parse_val(map->work_buf);
+ trace_regmap_reg_read(map->dev, reg, *val);
+ }
return ret;
}