[PATCH v2 2/6] hwmon: (sht3x)remove blocking_io property

[JuenKit Yip]

Due to no support on clock-strench, blocking mode was removed and
now single-shot mode only uses non-blocking mode.

Signed-off-by: JuenKit Yip <JuenKit_Yip@xxxxxxxxxxx>
---
 Documentation/hwmon/sht3x.rst | 14 ++++++--------
 drivers/hwmon/sht3x.c         | 33 +++++++++++----------------------
 2 files changed, 17 insertions(+), 30 deletions(-)

diff --git a/Documentation/hwmon/sht3x.rst b/Documentation/hwmon/sht3x.rst
index 31fd36b14..be70e2543 100644
--- a/Documentation/hwmon/sht3x.rst
+++ b/Documentation/hwmon/sht3x.rst
@@ -28,16 +28,14 @@ The device communicates with the I2C protocol. Sensors can have the I2C
 addresses 0x44 or 0x45, depending on the wiring. See
 Documentation/i2c/instantiating-devices.rst for methods to instantiate the device.
 
-There are two options configurable by means of sht3x_data:
-
-1. blocking (pull the I2C clock line down while performing the measurement) or
-   non-blocking mode. Blocking mode will guarantee the fastest result but
-   the I2C bus will be busy during that time. By default, non-blocking mode
-   is used. Make sure clock-stretching works properly on your device if you
-   want to use blocking mode.
-2. high or low accuracy. High accuracy is used by default and using it is
+There is only one option configurable by means of sht3x_data:
+
+   high or low accuracy. High accuracy is used by default and using it is
    strongly recommended.
 
+Even if sht3x sensor supports clock-strech(blocking mode) and non-strench
+(non-blocking mode) in single-shot mode, this driver only supports the latter.
+
 The sht3x sensor supports a single shot mode as well as 5 periodic measure
 modes, which can be controlled with the update_interval sysfs interface.
 The allowed update_interval in milliseconds are as follows:
diff --git a/drivers/hwmon/sht3x.c b/drivers/hwmon/sht3x.c
index 580704d93..bbe556f44 100644
--- a/drivers/hwmon/sht3x.c
+++ b/drivers/hwmon/sht3x.c
@@ -22,12 +22,10 @@
 #include <linux/jiffies.h>
 
 /* commands (high precision mode) */
-static const unsigned char sht3x_cmd_measure_blocking_hpm[]    = { 0x2c, 0x06 };
-static const unsigned char sht3x_cmd_measure_nonblocking_hpm[] = { 0x24, 0x00 };
+static const unsigned char sht3x_cmd_measure_single_hpm[] = { 0x24, 0x00 };
 
 /* commands (low power mode) */
-static const unsigned char sht3x_cmd_measure_blocking_lpm[]    = { 0x2c, 0x10 };
-static const unsigned char sht3x_cmd_measure_nonblocking_lpm[] = { 0x24, 0x16 };
+static const unsigned char sht3x_cmd_measure_single_lpm[] = { 0x24, 0x16 };
 
 /* commands for periodic mode */
 static const unsigned char sht3x_cmd_measure_periodic_mode[]   = { 0xe0, 0x00 };
@@ -41,9 +39,9 @@ static const unsigned char sht3x_cmd_heater_off[]              = { 0x30, 0x66 };
 static const unsigned char sht3x_cmd_read_status_reg[]         = { 0xf3, 0x2d };
 static const unsigned char sht3x_cmd_clear_status_reg[]        = { 0x30, 0x41 };
 
-/* delays for non-blocking i2c commands, both in us */
-#define SHT3X_NONBLOCKING_WAIT_TIME_HPM  15000
-#define SHT3X_NONBLOCKING_WAIT_TIME_LPM   4000
+/* delays for single-shot mode i2c commands, both in us */
+#define SHT3X_SINGLE_WAIT_TIME_HPM  15000
+#define SHT3X_SINGLE_WAIT_TIME_LPM   4000
 
 #define SHT3X_WORD_LEN         2
 #define SHT3X_CMD_LENGTH       2
@@ -134,7 +132,6 @@ struct sht3x_data {
 	const unsigned char *command;
 	u32 wait_time;			/* in us*/
 	unsigned long last_update;	/* last update in periodic mode*/
-	bool blocking_io;
 	bool high_precision;
 
 	/*
@@ -432,26 +429,19 @@ static ssize_t humidity1_limit_store(struct device *dev,
 static void sht3x_select_command(struct sht3x_data *data)
 {
 	/*
-	 * In blocking mode (clock stretching mode) the I2C bus
-	 * is blocked for other traffic, thus the call to i2c_master_recv()
-	 * will wait until the data is ready. For non blocking mode, we
-	 * have to wait ourselves.
+	 * For single-shot mode, only non blocking mode is support,
+	 * we have to wait ourselves for result.
 	 */
 	if (data->mode > 0) {
 		data->command = sht3x_cmd_measure_periodic_mode;
 		data->wait_time = 0;
-	} else if (data->blocking_io) {
-		data->command = data->high_precision ?
-				sht3x_cmd_measure_blocking_hpm :
-				sht3x_cmd_measure_blocking_lpm;
-		data->wait_time = 0;
 	} else {
 		if (data->high_precision) {
-			data->command = sht3x_cmd_measure_nonblocking_hpm;
-			data->wait_time = SHT3X_NONBLOCKING_WAIT_TIME_HPM;
+			data->command = sht3x_cmd_measure_single_hpm;
+			data->wait_time = SHT3X_SINGLE_WAIT_TIME_HPM;
 		} else {
-			data->command = sht3x_cmd_measure_nonblocking_lpm;
-			data->wait_time = SHT3X_NONBLOCKING_WAIT_TIME_LPM;
+			data->command = sht3x_cmd_measure_single_lpm;
+			data->wait_time = SHT3X_SINGLE_WAIT_TIME_LPM;
 		}
 	}
 }
@@ -689,7 +679,6 @@ static int sht3x_probe(struct i2c_client *client)
 	if (!data)
 		return -ENOMEM;
 
-	data->blocking_io = false;
 	data->high_precision = true;
 	data->mode = 0;
 	data->last_update = jiffies - msecs_to_jiffies(3000);
-- 
2.30.2