On 4/10/19 3:39 PM, Adamski, Krzysztof (Nokia - PL/Wroclaw) wrote:
Register custom sysfs attribute to be registered by pmbus allowing
read/write access to the manufacturer specific SAMPLES_FOR_AVG register.
This register allows setting the number of samples used in computing the
average values (PMBUS_VIRT_READ_*_AVG). The number we write is an
exponent of base 2 of the number of samples so for example writing 3
will result in 8 samples average.
Signed-off-by: Krzysztof Adamski <krzysztof.adamski@xxxxxxxxx>
---
drivers/hwmon/pmbus/lm25066.c | 45 +++++++++++++++++++++++++++++++++++
1 file changed, 45 insertions(+)
diff --git a/drivers/hwmon/pmbus/lm25066.c b/drivers/hwmon/pmbus/lm25066.c
index 53db78753a0d..c78af0a7e5ff 100644
--- a/drivers/hwmon/pmbus/lm25066.c
+++ b/drivers/hwmon/pmbus/lm25066.c
@@ -26,6 +26,7 @@
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/i2c.h>
+#include <linux/log2.h>
#include "pmbus.h"
enum chips { lm25056, lm25066, lm5064, lm5066, lm5066i };
@@ -38,6 +39,7 @@ enum chips { lm25056, lm25066, lm5064, lm5066, lm5066i };
#define LM25066_READ_PIN_PEAK 0xd5
#define LM25066_CLEAR_PIN_PEAK 0xd6
#define LM25066_DEVICE_SETUP 0xd9
+#define LM25066_SAMPLES_FOR_AVG 0xdb
#define LM25066_READ_AVG_VIN 0xdc
#define LM25066_READ_AVG_VOUT 0xdd
#define LM25066_READ_AVG_IIN 0xde
@@ -405,6 +407,47 @@ static int lm25066_write_word_data(struct i2c_client *client, int page, int reg,
return ret;
}
+static ssize_t samples_for_avg_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct i2c_client *client = to_i2c_client(dev->parent);
+ int ret;
+
+ ret = pmbus_read_byte_data(client, 0, LM25066_SAMPLES_FOR_AVG);
+ if (ret < 0)
+ return ret;
+
+ return sprintf(buf, "%d\n", 1 << ret);
+}
+
+static ssize_t samples_for_avg_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct i2c_client *client = to_i2c_client(dev->parent);
+ int ret, val;
+
+ ret = kstrtoint(buf, 0, &val);
+ if (ret < 0)
+ return ret;
+
+ ret = pmbus_write_byte_data(client, 0, LM25066_SAMPLES_FOR_AVG,
+ ilog2(val));
+ if (ret < 0)
+ return ret;
+
+ return count;
+}
+
+static DEVICE_ATTR_RW(samples_for_avg);
+
+static struct attribute *lm25056_attrs[] = {
+ &dev_attr_samples_for_avg.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(lm25056); // should we set a name of this group to put all
+ // those attributes in subdirectory? Like "custom" ?
+
We don't add subdirectories for other chips, and we won't start it here.
I don't mind the attribute itself, but I do mind its name. We'll have
to find something more generic, such as 'num_samples' or just 'samples'.
I am open to suggestions. We'll also have to decide if the attribute(s)
should be limited to one per chip, or if there can be multiple attributes.
For example, MAX34462 has separate values for iout_samples and adc_average.
Do we want samples, {curr,in,power,...}_samples, or both ? Or even
currX_samples ?
Either case, this is needed for more than one pmbus chip (and I know
it is needed for some non-PMBus chips). I am inclined to add it as generic
attribute into the pmbus core instead (and possibly add it to the ABI).
Thanks,
Guenter
static int lm25066_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -476,6 +519,8 @@ static int lm25066_probe(struct i2c_client *client,
info->b[PSC_POWER] = coeff[PSC_POWER].b;
}
+ info->groups = lm25056_groups;
+
return pmbus_do_probe(client, id, info);
}
