* [PATCH] hwmon: (tps23861) fix byte order in current and voltage registers
@ 2022-07-21 3:22 Alexandru Gagniuc
2022-07-21 3:40 ` Guenter Roeck
0 siblings, 1 reply; 2+ messages in thread
From: Alexandru Gagniuc @ 2022-07-21 3:22 UTC (permalink / raw)
To: robert.marko, linux-hwmon; +Cc: luka.perkov, jdelvare, linux, Alexandru Gagniuc
Trying to use this driver on a big-endian machine results in garbage
values for voltage and current. The tps23861 registers are little-
endian, and regmap_read_bulk() does not do byte order conversion. Thus
on BE machines, the most significant bytes got modified, and were
trimmed by the VOLTAGE_CURRENT_MASK.
To resolve this use uint16_t values, and convert them to host byte
order using le16_to_cpu(). This results in correct readings on MIPS.
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
---
drivers/hwmon/tps23861.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/drivers/hwmon/tps23861.c b/drivers/hwmon/tps23861.c
index 8bd6435c13e8..e07f6b8a1898 100644
--- a/drivers/hwmon/tps23861.c
+++ b/drivers/hwmon/tps23861.c
@@ -140,7 +140,8 @@ static int tps23861_read_temp(struct tps23861_data *data, long *val)
static int tps23861_read_voltage(struct tps23861_data *data, int channel,
long *val)
{
- unsigned int regval;
+ uint16_t regval;
+ long raw_val;
int err;
if (channel < TPS23861_NUM_PORTS) {
@@ -155,7 +156,8 @@ static int tps23861_read_voltage(struct tps23861_data *data, int channel,
if (err < 0)
return err;
- *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, regval) * VOLTAGE_LSB) / 1000;
+ raw_val = le16_to_cpu(regval);
+ *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, raw_val) * VOLTAGE_LSB) / 1000;
return 0;
}
@@ -163,8 +165,9 @@ static int tps23861_read_voltage(struct tps23861_data *data, int channel,
static int tps23861_read_current(struct tps23861_data *data, int channel,
long *val)
{
- unsigned int current_lsb;
- unsigned int regval;
+ long raw_val, current_lsb;
+ uint16_t regval;
+
int err;
if (data->shunt_resistor == SHUNT_RESISTOR_DEFAULT)
@@ -178,7 +181,8 @@ static int tps23861_read_current(struct tps23861_data *data, int channel,
if (err < 0)
return err;
- *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, regval) * current_lsb) / 1000000;
+ raw_val = le16_to_cpu(regval);
+ *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, raw_val) * current_lsb) / 1000000;
return 0;
}
--
2.34.3
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] hwmon: (tps23861) fix byte order in current and voltage registers
2022-07-21 3:22 [PATCH] hwmon: (tps23861) fix byte order in current and voltage registers Alexandru Gagniuc
@ 2022-07-21 3:40 ` Guenter Roeck
0 siblings, 0 replies; 2+ messages in thread
From: Guenter Roeck @ 2022-07-21 3:40 UTC (permalink / raw)
To: Alexandru Gagniuc; +Cc: robert.marko, linux-hwmon, luka.perkov, jdelvare
On Wed, Jul 20, 2022 at 10:22:55PM -0500, Alexandru Gagniuc wrote:
> Trying to use this driver on a big-endian machine results in garbage
> values for voltage and current. The tps23861 registers are little-
> endian, and regmap_read_bulk() does not do byte order conversion. Thus
> on BE machines, the most significant bytes got modified, and were
> trimmed by the VOLTAGE_CURRENT_MASK.
>
> To resolve this use uint16_t values, and convert them to host byte
> order using le16_to_cpu(). This results in correct readings on MIPS.
>
> Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Applied.
Thanks,
Guenter
> ---
> drivers/hwmon/tps23861.c | 14 +++++++++-----
> 1 file changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/hwmon/tps23861.c b/drivers/hwmon/tps23861.c
> index 8bd6435c13e8..e07f6b8a1898 100644
> --- a/drivers/hwmon/tps23861.c
> +++ b/drivers/hwmon/tps23861.c
> @@ -140,7 +140,8 @@ static int tps23861_read_temp(struct tps23861_data *data, long *val)
> static int tps23861_read_voltage(struct tps23861_data *data, int channel,
> long *val)
> {
> - unsigned int regval;
> + uint16_t regval;
> + long raw_val;
> int err;
>
> if (channel < TPS23861_NUM_PORTS) {
> @@ -155,7 +156,8 @@ static int tps23861_read_voltage(struct tps23861_data *data, int channel,
> if (err < 0)
> return err;
>
> - *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, regval) * VOLTAGE_LSB) / 1000;
> + raw_val = le16_to_cpu(regval);
> + *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, raw_val) * VOLTAGE_LSB) / 1000;
>
> return 0;
> }
> @@ -163,8 +165,9 @@ static int tps23861_read_voltage(struct tps23861_data *data, int channel,
> static int tps23861_read_current(struct tps23861_data *data, int channel,
> long *val)
> {
> - unsigned int current_lsb;
> - unsigned int regval;
> + long raw_val, current_lsb;
> + uint16_t regval;
> +
> int err;
>
> if (data->shunt_resistor == SHUNT_RESISTOR_DEFAULT)
> @@ -178,7 +181,8 @@ static int tps23861_read_current(struct tps23861_data *data, int channel,
> if (err < 0)
> return err;
>
> - *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, regval) * current_lsb) / 1000000;
> + raw_val = le16_to_cpu(regval);
> + *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, raw_val) * current_lsb) / 1000000;
>
> return 0;
> }
^ permalink raw reply [flat|nested] 2+ messages in thread
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