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SubjectRe: [PATCH] hwmon: (pmbus/lm25066) Swap low/high current coefficients for LM5066(i)
On Wed, Nov 22, 2017 at 02:07:28PM -0800, Robert Lippert wrote:
> The _L low-current mode coefficient values should reference the
> datasheet rows with CL=VDD but it seems were mistakenly pulled from
> the rows with CL=GND.
>
> This causes the current/power to be reported as approximately double
> the actual value when CL=GND and half the actual value when CL=VDD.
>

This would affect all chips supported by this driver. Hmm, and I was sure
I tested this. I'll have to dig out my hardware and confirm.

The code currently only uses bit 4 of the DEVICE_SETUP (D9h) command
to determine which current limit setting to use. Looking into the
datasheet, it looks like it also has to evaluate bit 2, and I wonder
if there is a means to determine CL if bit 2 = 0. Any idea ?
Does bit 4 report the CL pin value if bit 2 = 0 ?

Thanks,
Guenter

> Signed-off-by: Robert Lippert <rlippert@google.com>
> ---
> drivers/hwmon/pmbus/lm25066.c | 24 ++++++++++++------------
> 1 file changed, 12 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/hwmon/pmbus/lm25066.c b/drivers/hwmon/pmbus/lm25066.c
> index 10d17fb8f283..aa052f4449a9 100644
> --- a/drivers/hwmon/pmbus/lm25066.c
> +++ b/drivers/hwmon/pmbus/lm25066.c
> @@ -191,19 +191,19 @@ static struct __coeff lm25066_coeff[6][PSC_NUM_CLASSES + 2] = {
> .R = -2,
> },
> [PSC_CURRENT_IN] = {
> - .m = 10753,
> + .m = 5405,
> .R = -2,
> },
> [PSC_CURRENT_IN_L] = {
> - .m = 5405,
> + .m = 10753,
> .R = -2,
> },
> [PSC_POWER] = {
> - .m = 1204,
> + .m = 605,
> .R = -3,
> },
> [PSC_POWER_L] = {
> - .m = 605,
> + .m = 1204,
> .R = -3,
> },
> [PSC_TEMPERATURE] = {
> @@ -222,23 +222,23 @@ static struct __coeff lm25066_coeff[6][PSC_NUM_CLASSES + 2] = {
> .R = -2,
> },
> [PSC_CURRENT_IN] = {
> - .m = 15076,
> - .b = -504,
> + .m = 7645,
> + .b = 100,
> .R = -2,
> },
> [PSC_CURRENT_IN_L] = {
> - .m = 7645,
> - .b = 100,
> + .m = 15076,
> + .b = -504,
> .R = -2,
> },
> [PSC_POWER] = {
> - .m = 1701,
> - .b = -4000,
> + .m = 861,
> + .b = -965,
> .R = -3,
> },
> [PSC_POWER_L] = {
> - .m = 861,
> - .b = -965,
> + .m = 1701,
> + .b = -4000,
> .R = -3,
> },
> [PSC_TEMPERATURE] = {
> --
> 2.15.0.448.gf294e3d99a-goog
>

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