target/linux/generic/backport-5.10/873-v6.0-hwmon-tps23861-fix-byte-order-in-current-and-voltage.patch

   1 From 0eabb1396656f215a5333a9444158b17b0fd3247 Mon Sep 17 00:00:00 2001
   2 From: Alexandru Gagniuc <mr.nuke.me@gmail.com>
   3 Date: Wed, 20 Jul 2022 22:22:55 -0500
   4 Subject: hwmon: (tps23861) fix byte order in current and voltage registers
   5
   6 Trying to use this driver on a big-endian machine results in garbage
   7 values for voltage and current. The tps23861 registers are little-
   8 endian, and regmap_read_bulk() does not do byte order conversion. Thus
   9 on BE machines, the most significant bytes got modified, and were
  10 trimmed by the VOLTAGE_CURRENT_MASK.
  11
  12 To resolve this use uint16_t values, and convert them to host byte
  13 order using le16_to_cpu(). This results in correct readings on MIPS.
  14
  15 Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
  16 Link: https://lore.kernel.org/r/20220721032255.2850647-1-mr.nuke.me@gmail.com
  17 [groeck: Use __le16 instead of uint16_t]
  18 Signed-off-by: Guenter Roeck <linux@roeck-us.net>
  19 ---
  20  drivers/hwmon/tps23861.c | 14 +++++++++-----
  21  1 file changed, 9 insertions(+), 5 deletions(-)
  22
  23 --- a/drivers/hwmon/tps23861.c
  24 +++ b/drivers/hwmon/tps23861.c
  25 @@ -140,7 +140,8 @@ static int tps23861_read_temp(struct tps
  26  static int tps23861_read_voltage(struct tps23861_data *data, int channel,
  27                                  long *val)
  28  {
  29 -       unsigned int regval;
  30 +       __le16 regval;
  31 +       long raw_val;
  32         int err;
  33
  34         if (channel < TPS23861_NUM_PORTS) {
  35 @@ -155,7 +156,8 @@ static int tps23861_read_voltage(struct
  36         if (err < 0)
  37                 return err;
  38
  39 -       *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, regval) * VOLTAGE_LSB) / 1000;
  40 +       raw_val = le16_to_cpu(regval);
  41 +       *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, raw_val) * VOLTAGE_LSB) / 1000;
  42
  43         return 0;
  44  }
  45 @@ -163,8 +165,9 @@ static int tps23861_read_voltage(struct
  46  static int tps23861_read_current(struct tps23861_data *data, int channel,
  47                                  long *val)
  48  {
  49 -       unsigned int current_lsb;
  50 -       unsigned int regval;
  51 +       long raw_val, current_lsb;
  52 +       __le16 regval;
  53 +
  54         int err;
  55
  56         if (data->shunt_resistor == SHUNT_RESISTOR_DEFAULT)
  57 @@ -178,7 +181,8 @@ static int tps23861_read_current(struct
  58         if (err < 0)
  59                 return err;
  60
  61 -       *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, regval) * current_lsb) / 1000000;
  62 +       raw_val = le16_to_cpu(regval);
  63 +       *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, raw_val) * current_lsb) / 1000000;
  64
  65         return 0;
  66  }