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authorJuenKit Yip <JuenKit_Yip@hotmail.com>2023-06-16 19:00:15 +0300
committerGuenter Roeck <linux@roeck-us.net>2023-06-17 18:56:42 +0300
commit3d2c211c0d2b5955b4ec9a1af7d59e8bed00c7fe (patch)
treece0ff41b881c50a952af0a2f1f22ead01c97c568 /drivers/hwmon
parent7d6d53ba3bccc5497e5bda5da4868c410f3eaa02 (diff)
downloadlinux-3d2c211c0d2b5955b4ec9a1af7d59e8bed00c7fe.tar.xz
hwmon: (sht3x) add medium repeatability support
Add support for medium repeatability. Per datasheet: The stated repeatability is 3 times the standard deviation (3σ) of multiple consecutive measurements at the stated repeatability and at constant ambient conditions. It is a measure for the noise on the physical sensor output. Different measurement modes allow for high/medium/low repeatability. For the humidity sensor, repeatability is documented as 0.25% RH for low repeatability, 0.15% RH for medium repeatability, and 0.10% RH for high repeatability. Support all three modes. Signed-off-by: JuenKit Yip <JuenKit_Yip@hotmail.com> Link: https://lore.kernel.org/r/DB4PR10MB6261A70CD0444248ADDCC3219258A@DB4PR10MB6261.EURPRD10.PROD.OUTLOOK.COM [groeck: Added details to description] Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon')
-rw-r--r--drivers/hwmon/sht3x.c24
1 files changed, 24 insertions, 0 deletions
diff --git a/drivers/hwmon/sht3x.c b/drivers/hwmon/sht3x.c
index fff92e96a6b3..111b86d9adb5 100644
--- a/drivers/hwmon/sht3x.c
+++ b/drivers/hwmon/sht3x.c
@@ -24,6 +24,9 @@
/* commands (high repeatability mode) */
static const unsigned char sht3x_cmd_measure_single_hpm[] = { 0x24, 0x00 };
+/* commands (medium repeatability mode) */
+static const unsigned char sht3x_cmd_measure_single_mpm[] = { 0x24, 0x0b };
+
/* commands (low repeatability mode) */
static const unsigned char sht3x_cmd_measure_single_lpm[] = { 0x24, 0x16 };
@@ -41,6 +44,7 @@ static const unsigned char sht3x_cmd_clear_status_reg[] = { 0x30, 0x41 };
/* delays for single-shot mode i2c commands, both in us */
#define SHT3X_SINGLE_WAIT_TIME_HPM 15000
+#define SHT3X_SINGLE_WAIT_TIME_MPM 6000
#define SHT3X_SINGLE_WAIT_TIME_LPM 4000
#define SHT3X_WORD_LEN 2
@@ -68,6 +72,7 @@ enum sht3x_limits {
enum sht3x_repeatability {
low_repeatability,
+ medium_repeatability,
high_repeatability,
};
@@ -87,6 +92,20 @@ static const char periodic_measure_commands_hpm[][SHT3X_CMD_LENGTH] = {
{0x27, 0x37},
};
+/* periodic measure commands (medium repeatability) */
+static const char periodic_measure_commands_mpm[][SHT3X_CMD_LENGTH] = {
+ /* 0.5 measurements per second */
+ {0x20, 0x24},
+ /* 1 measurements per second */
+ {0x21, 0x26},
+ /* 2 measurements per second */
+ {0x22, 0x20},
+ /* 4 measurements per second */
+ {0x23, 0x22},
+ /* 10 measurements per second */
+ {0x27, 0x21},
+};
+
/* periodic measure commands (low repeatability mode) */
static const char periodic_measure_commands_lpm[][SHT3X_CMD_LENGTH] = {
/* 0.5 measurements per second */
@@ -444,6 +463,9 @@ static void sht3x_select_command(struct sht3x_data *data)
if (data->repeatability == high_repeatability) {
data->command = sht3x_cmd_measure_single_hpm;
data->wait_time = SHT3X_SINGLE_WAIT_TIME_HPM;
+ } else if (data->repeatability == medium_repeatability) {
+ data->command = sht3x_cmd_measure_single_mpm;
+ data->wait_time = SHT3X_SINGLE_WAIT_TIME_MPM;
} else {
data->command = sht3x_cmd_measure_single_lpm;
data->wait_time = SHT3X_SINGLE_WAIT_TIME_LPM;
@@ -591,6 +613,8 @@ static ssize_t update_interval_store(struct device *dev,
if (mode > 0) {
if (data->repeatability == high_repeatability)
command = periodic_measure_commands_hpm[mode - 1];
+ else if (data->repeatability == medium_repeatability)
+ command = periodic_measure_commands_mpm[mode - 1];
else
command = periodic_measure_commands_lpm[mode - 1];