On 4/13/19 9:03 AM, Adamski, Krzysztof (Nokia - PL/Wroclaw) wrote:
Those virtual registers can be used to export manufacturer specific
functionality for controlling the number of samples for average values
reported by the device.
Signed-off-by: Krzysztof Adamski <krzysztof.adamski@xxxxxxxxx>
---
Documentation/hwmon/sysfs-interface | 18 +++++
drivers/hwmon/pmbus/pmbus.h | 15 ++++
drivers/hwmon/pmbus/pmbus_core.c | 114 ++++++++++++++++++++++++++++
3 files changed, 147 insertions(+)
diff --git a/Documentation/hwmon/sysfs-interface b/Documentation/hwmon/sysfs-interface
index 2b9e1005d88b..7b91706d01c8 100644
--- a/Documentation/hwmon/sysfs-interface
+++ b/Documentation/hwmon/sysfs-interface
@@ -756,6 +756,24 @@ intrusion[0-*]_beep
1: enable
RW
+********************************
+* Average sample configuration *
+********************************
+
+Devices allowing for reading {in,power,curr,temp}_average values may export
+attributes for controlling number of samples used to compute average.
+
+samples Sets number of average samples for all types of measurements.
+ RW
+
+in_samples
+power_samples
+curr_samples
+temp_samples Sets number of average samples for specific type of measurements.
+ Note that on some devices it won't be possible to set all of them
+ to different values so changing one might also change some others.
+ RW
+
Separate patch for the above, please. Adding the ABI is one subject, adding support
for it into a driver (or driver core) is another.
sysfs attribute writes interpretation
-------------------------------------
diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
index 1d24397d36ec..e73289cc867d 100644
--- a/drivers/hwmon/pmbus/pmbus.h
+++ b/drivers/hwmon/pmbus/pmbus.h
@@ -217,6 +217,20 @@ enum pmbus_regs {
PMBUS_VIRT_PWM_ENABLE_2,
PMBUS_VIRT_PWM_ENABLE_3,
PMBUS_VIRT_PWM_ENABLE_4,
+
+ /* Samples for average
+ *
+ * Drivers wanting to expose functionality for changing the number of
+ * samples used for average values should implement support in
+ * {read,write}_word_data callback for either PMBUS_VIRT_SAMPLES if it
+ * applies to all types of measurements, or any number of specific
+ * PMBUS_VIRT_*_SAMPLES registers to allow for individual control.
+ */
+ PMBUS_VIRT_SAMPLES,
+ PMBUS_VIRT_IN_SAMPLES,
+ PMBUS_VIRT_CURR_SAMPLES,
+ PMBUS_VIRT_POWER_SAMPLES,
+ PMBUS_VIRT_TEMP_SAMPLES,
};
/*
@@ -371,6 +385,7 @@ enum pmbus_sensor_classes {
#define PMBUS_HAVE_STATUS_VMON BIT(19)
#define PMBUS_HAVE_PWM12 BIT(20)
#define PMBUS_HAVE_PWM34 BIT(21)
+#define PMBUS_HAVE_SAMPLES BIT(22)
#define PMBUS_PAGE_VIRTUAL BIT(31)
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 2e2b5851139c..31b6bf49518c 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -1901,6 +1901,116 @@ static int pmbus_add_fan_attributes(struct i2c_client *client,
return 0;
}
+struct pmbus_samples_attr {
+ int reg;
+ char *name;
+};
+
+struct pmbus_samples_reg {
+ int page;
+ struct pmbus_samples_attr *attr;
+ struct device_attribute dev_attr;
+};
+
+static struct pmbus_samples_attr pmbus_samples_registers[] = {
+ {
+ .reg = PMBUS_VIRT_SAMPLES,
+ .name = "samples",
+ }, {
+ .reg = PMBUS_VIRT_IN_SAMPLES,
+ .name = "in_samples",
+ }, {
+ .reg = PMBUS_VIRT_CURR_SAMPLES,
+ .name = "curr_samples",
+ }, {
+ .reg = PMBUS_VIRT_POWER_SAMPLES,
+ .name = "power_samples",
+ }, {
+ .reg = PMBUS_VIRT_TEMP_SAMPLES,
+ .name = "temp_samples",
+ }
+};
+
+#define to_samples_reg(x) container_of(x, struct pmbus_samples_reg, dev_attr)
+
+static ssize_t pmbus_show_samples(struct device *dev,
+ struct device_attribute *devattr, char *buf)
+{
+ int val;
+ struct i2c_client *client = to_i2c_client(dev->parent);
+ struct pmbus_samples_reg *reg = to_samples_reg(devattr);
+
+ val = _pmbus_read_word_data(client, reg->page, reg->attr->reg);
+ if (val < 0)
+ return val;
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", val);
+}
+
+static ssize_t pmbus_set_samples(struct device *dev,
+ struct device_attribute *devattr,
+ const char *buf, size_t count)
+{
+ int ret;
+ long val;
+ struct i2c_client *client = to_i2c_client(dev->parent);
+ struct pmbus_samples_reg *reg = to_samples_reg(devattr);
+
+ if (kstrtol(buf, 0, &val) < 0)
+ return -EINVAL;
+
+ ret = _pmbus_write_word_data(client, reg->page, reg->attr->reg, val);
+
+ return ret ? : count;
+}
+
+static int pmbus_add_samples_attr(struct pmbus_data *data, int page,
+ struct pmbus_samples_attr *attr)
+{
+ struct pmbus_samples_reg *reg;
+
+ reg = devm_kzalloc(data->dev, sizeof(*reg), GFP_KERNEL);
+ if (!reg)
+ return -ENOMEM;
+
+ reg->attr = attr;
+ reg->page = page;
+
+ pmbus_dev_attr_init(®->dev_attr, attr->name, (S_IWUSR | S_IRUGO),
S_IWUSR ran out of favor and generates a checkpatch warning.
Please use 0644.
+ pmbus_show_samples, pmbus_set_samples);
+
+ return pmbus_add_attribute(data, ®->dev_attr.attr);
+}
+
+static int pmbus_add_samples_attributes(struct i2c_client *client,
+ struct pmbus_data *data)
+{
+ const struct pmbus_driver_info *info = data->info;
+ int page;
+
+ for (page = 0; page < info->pages; page++) {
This won't work as intended on multi-page chips. If the driver writer
is not careful, it will try to generate multiple similar attributes,
one per page. I would suggest to only check this for page 0.
At some point we may need to add a separate func pointer for
chip specific attributes, but that should do for now.
+ int s;:
+
+ if (!(info->func[page] & PMBUS_HAVE_SAMPLES))
+ continue;
+
+ for (s = 0; s < ARRAY_SIZE(pmbus_samples_registers); s++) {
+ int ret;
+ struct pmbus_samples_attr *attr;
+
Please use reverse christmas tree here
struct pmbus_samples_attr *attr;
int ret;
+ attr = &pmbus_samples_registers[s];
+ if (!pmbus_check_word_register(client, page, attr->reg))
+ continue;
+
+ ret = pmbus_add_samples_attr(data, page, attr);
+ if (ret)
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
static int pmbus_find_attributes(struct i2c_client *client,
struct pmbus_data *data)
{
@@ -1932,6 +2042,10 @@ static int pmbus_find_attributes(struct i2c_client *client,
/* Fans */
ret = pmbus_add_fan_attributes(client, data);
+ if (ret)
+ return ret;
+
+ ret = pmbus_add_samples_attributes(client, data);
return ret;
}
