On 4/14/19 12:00 PM, Adamski, Krzysztof (Nokia - PL/Wroclaw) wrote:
On Sun, Apr 14, 2019 at 07:37:35AM -0700, Guenter Roeck wrote:
On 4/13/19 9:03 AM, Adamski, Krzysztof (Nokia - PL/Wroclaw) wrote:
Manufacturer specific SAMPLES_FOR_AVG 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 | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/drivers/hwmon/pmbus/lm25066.c b/drivers/hwmon/pmbus/lm25066.c
index 53db78753a0d..b560d33db459 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 };
@@ -39,12 +40,15 @@ enum chips { lm25056, lm25066, lm5064, lm5066, lm5066i };
#define LM25066_CLEAR_PIN_PEAK 0xd6
#define LM25066_DEVICE_SETUP 0xd9
#define LM25066_READ_AVG_VIN 0xdc
+#define LM25066_SAMPLES_FOR_AVG 0xdb
#define LM25066_READ_AVG_VOUT 0xdd
#define LM25066_READ_AVG_IIN 0xde
#define LM25066_READ_AVG_PIN 0xdf
#define LM25066_DEV_SETUP_CL BIT(4) /* Current limit */
+#define LM25066_SAMPLES_FOR_AVG_MAX 4096
+
/* LM25056 only */
#define LM25056_VAUX_OV_WARN_LIMIT 0xe3
@@ -284,6 +288,10 @@ static int lm25066_read_word_data(struct i2c_client *client, int page, int reg)
case PMBUS_VIRT_RESET_PIN_HISTORY:
ret = 0;
break;
+ case PMBUS_VIRT_SAMPLES:
+ ret = pmbus_read_byte_data(client, 0, LM25066_SAMPLES_FOR_AVG);
if (ret < 0)
return ret;
Good point. However the convention for this switch is to break instead
of returning early. I would stick with that if you don't mind.
I don't mind if you want to use
if (ret < 0)
break;
instead, but I do mind if you want to convert an error code into an undefined value.
+ ret = 1 << ret;
+ break;
default:
ret = -ENODATA;
break;
@@ -398,6 +406,11 @@ static int lm25066_write_word_data(struct i2c_client *client, int page, int reg,
case PMBUS_VIRT_RESET_PIN_HISTORY:
ret = pmbus_write_byte(client, 0, LM25066_CLEAR_PIN_PEAK);
break;
+ case PMBUS_VIRT_SAMPLES:
+ word = clamp_val(word, 0, LM25066_SAMPLES_FOR_AVG_MAX);
0 is not valid, and ilog2(0) returns -1 (or is undefined).
True, I'll clamp with minimum 1 to fix that. I don't think it's worth
returning an error for 0. Do you?
The whole point of using clamp() is to avoid returning an error. Returning an error
for values <= 0 but clamping large positive values to 4096 seems inconsistent.
Guenter
+ ret = pmbus_write_byte_data(client, 0, LM25066_SAMPLES_FOR_AVG,
+ ilog2(word));
+ break;
default:
ret = -ENODATA;
break;
@@ -438,7 +451,7 @@ static int lm25066_probe(struct i2c_client *client,
info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VMON
| PMBUS_HAVE_PIN | PMBUS_HAVE_IIN | PMBUS_HAVE_STATUS_INPUT
- | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
+ | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_SAMPLES;
if (data->id == lm25056) {
info->func[0] |= PMBUS_HAVE_STATUS_VMON;
Krzysztof
