iio: humidity: hdc3020: switch to 16bit register defines

Switch to 16bit register defines and drop the const u8 register pairs.
By doing so we change the parameter of functions for reading and writing
to the device. Additionally create helper functions that are aware of the
new register format and apply them wherever possible.
Signed-off-by: Dimitri Fedrau <dima.fedrau@gmail.com>
Link: https://lore.kernel.org/r/20240214085350.19382-2-dima.fedrau@gmail.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/humidity/hdc3020.c

@@ -21,26 +21,22 @@
 
 #include <linux/iio/iio.h>
 
-#define HDC3020_HEATER_CMD_MSB		0x30 /* shared by all heater commands */
-#define HDC3020_HEATER_ENABLE		0x6D
-#define HDC3020_HEATER_DISABLE		0x66
-#define HDC3020_HEATER_CONFIG		0x6E
+#define HDC3020_S_AUTO_10HZ_MOD0	0x2737
+#define HDC3020_HEATER_DISABLE		0x3066
+#define HDC3020_HEATER_ENABLE		0x306D
+#define HDC3020_HEATER_CONFIG		0x306E
+#define HDC3020_EXIT_AUTO		0x3093
+#define HDC3020_R_T_RH_AUTO		0xE000
+#define HDC3020_R_T_LOW_AUTO		0xE002
+#define HDC3020_R_T_HIGH_AUTO		0xE003
+#define HDC3020_R_RH_LOW_AUTO		0xE004
+#define HDC3020_R_RH_HIGH_AUTO		0xE005
 
 #define HDC3020_READ_RETRY_TIMES	10
 #define HDC3020_BUSY_DELAY_MS		10
 
 #define HDC3020_CRC8_POLYNOMIAL		0x31
 
-static const u8 HDC3020_S_AUTO_10HZ_MOD0[2] = { 0x27, 0x37 };
-
-static const u8 HDC3020_EXIT_AUTO[2] = { 0x30, 0x93 };
-
-static const u8 HDC3020_R_T_RH_AUTO[2] = { 0xE0, 0x00 };
-static const u8 HDC3020_R_T_LOW_AUTO[2] = { 0xE0, 0x02 };
-static const u8 HDC3020_R_T_HIGH_AUTO[2] = { 0xE0, 0x03 };
-static const u8 HDC3020_R_RH_LOW_AUTO[2] = { 0xE0, 0x04 };
-static const u8 HDC3020_R_RH_HIGH_AUTO[2] = { 0xE0, 0x05 };
-
 struct hdc3020_data {
 	struct i2c_client *client;
 	/*
@@ -82,7 +78,7 @@ static const struct iio_chan_spec hdc3020_channels[] = {
 
 DECLARE_CRC8_TABLE(hdc3020_crc8_table);
 
-static int hdc3020_write_bytes(struct hdc3020_data *data, const u8 *buf, u8 len)
+static int hdc3020_write_bytes(struct hdc3020_data *data, u8 *buf, u8 len)
 {
 	struct i2c_client *client = data->client;
 	struct i2c_msg msg;
@@ -90,7 +86,7 @@ static int hdc3020_write_bytes(struct hdc3020_data *data, const u8 *buf, u8 len)
 
 	msg.addr = client->addr;
 	msg.flags = 0;
-	msg.buf = (char *)buf;
+	msg.buf = buf;
 	msg.len = len;
 
 	/*
@@ -109,26 +105,28 @@ static int hdc3020_write_bytes(struct hdc3020_data *data, const u8 *buf, u8 len)
 	return -ETIMEDOUT;
 }
 
-static int hdc3020_read_bytes(struct hdc3020_data *data, const u8 *buf,
-			      void *val, int len)
+static
+int hdc3020_read_bytes(struct hdc3020_data *data, u16 reg, u8 *buf, int len)
 {
+	u8 reg_buf[2];
 	int ret, cnt;
 	struct i2c_client *client = data->client;
 	struct i2c_msg msg[2] = {
 		[0] = {
 			.addr = client->addr,
 			.flags = 0,
-			.buf = (char *)buf,
+			.buf = reg_buf,
 			.len = 2,
 		},
 		[1] = {
 			.addr = client->addr,
 			.flags = I2C_M_RD,
-			.buf = val,
+			.buf = buf,
 			.len = len,
 		},
 	};
 
+	put_unaligned_be16(reg, reg_buf);
 	/*
 	 * During the measurement process, HDC3020 will not return data.
 	 * So wait for a while and try again
@@ -145,48 +143,12 @@ static int hdc3020_read_bytes(struct hdc3020_data *data, const u8 *buf,
 	return -ETIMEDOUT;
 }
 
-static int hdc3020_read_measurement(struct hdc3020_data *data,
-				    enum iio_chan_type type, int *val)
-{
-	u8 crc, buf[6];
-	int ret;
-
-	ret = hdc3020_read_bytes(data, HDC3020_R_T_RH_AUTO, buf, 6);
-	if (ret < 0)
-		return ret;
-
-	/* CRC check of the temperature measurement */
-	crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE);
-	if (crc != buf[2])
-		return -EINVAL;
-
-	/* CRC check of the relative humidity measurement */
-	crc = crc8(hdc3020_crc8_table, buf + 3, 2, CRC8_INIT_VALUE);
-	if (crc != buf[5])
-		return -EINVAL;
-
-	if (type == IIO_TEMP)
-		*val = get_unaligned_be16(buf);
-	else if (type == IIO_HUMIDITYRELATIVE)
-		*val = get_unaligned_be16(&buf[3]);
-	else
-		return -EINVAL;
-
-	return 0;
-}
-
-/*
- * After exiting the automatic measurement mode or resetting, the peak
- * value will be reset to the default value
- * This method is used to get the highest temp measured during automatic
- * measurement
- */
-static int hdc3020_read_high_peak_t(struct hdc3020_data *data, int *val)
+static int hdc3020_read_be16(struct hdc3020_data *data, u16 reg)
 {
 	u8 crc, buf[3];
 	int ret;
 
-	ret = hdc3020_read_bytes(data, HDC3020_R_T_HIGH_AUTO, buf, 3);
+	ret = hdc3020_read_bytes(data, reg, buf, 3);
 	if (ret < 0)
 		return ret;
 
@@ -194,73 +156,43 @@ static int hdc3020_read_high_peak_t(struct hdc3020_data *data, int *val)
 	if (crc != buf[2])
 		return -EINVAL;
 
-	*val = get_unaligned_be16(buf);
-
-	return 0;
+	return get_unaligned_be16(buf);
 }
 
-/*
- * This method is used to get the lowest temp measured during automatic
- * measurement
- */
-static int hdc3020_read_low_peak_t(struct hdc3020_data *data, int *val)
+static int hdc3020_exec_cmd(struct hdc3020_data *data, u16 reg)
 {
-	u8 crc, buf[3];
-	int ret;
-
-	ret = hdc3020_read_bytes(data, HDC3020_R_T_LOW_AUTO, buf, 3);
-	if (ret < 0)
-		return ret;
-
-	crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE);
-	if (crc != buf[2])
-		return -EINVAL;
-
-	*val = get_unaligned_be16(buf);
+	u8 reg_buf[2];
 
-	return 0;
+	put_unaligned_be16(reg, reg_buf);
+	return hdc3020_write_bytes(data, reg_buf, 2);
 }
 
-/*
- * This method is used to get the highest humidity measured during automatic
- * measurement
- */
-static int hdc3020_read_high_peak_rh(struct hdc3020_data *data, int *val)
+static int hdc3020_read_measurement(struct hdc3020_data *data,
+				    enum iio_chan_type type, int *val)
 {
-	u8 crc, buf[3];
+	u8 crc, buf[6];
 	int ret;
 
-	ret = hdc3020_read_bytes(data, HDC3020_R_RH_HIGH_AUTO, buf, 3);
+	ret = hdc3020_read_bytes(data, HDC3020_R_T_RH_AUTO, buf, 6);
 	if (ret < 0)
 		return ret;
 
+	/* CRC check of the temperature measurement */
 	crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE);
 	if (crc != buf[2])
 		return -EINVAL;
 
-	*val = get_unaligned_be16(buf);
-
-	return 0;
-}
-
-/*
- * This method is used to get the lowest humidity measured during automatic
- * measurement
- */
-static int hdc3020_read_low_peak_rh(struct hdc3020_data *data, int *val)
-{
-	u8 crc, buf[3];
-	int ret;
-
-	ret = hdc3020_read_bytes(data, HDC3020_R_RH_LOW_AUTO, buf, 3);
-	if (ret < 0)
-		return ret;
-
-	crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE);
-	if (crc != buf[2])
+	/* CRC check of the relative humidity measurement */
+	crc = crc8(hdc3020_crc8_table, buf + 3, 2, CRC8_INIT_VALUE);
+	if (crc != buf[5])
 		return -EINVAL;
 
-	*val = get_unaligned_be16(buf);
+	if (type == IIO_TEMP)
+		*val = get_unaligned_be16(buf);
+	else if (type == IIO_HUMIDITYRELATIVE)
+		*val = get_unaligned_be16(&buf[3]);
+	else
+		return -EINVAL;
 
 	return 0;
 }
@@ -286,28 +218,28 @@ static int hdc3020_read_raw(struct iio_dev *indio_dev,
 	}
 	case IIO_CHAN_INFO_PEAK: {
 		guard(mutex)(&data->lock);
-		if (chan->type == IIO_TEMP) {
-			ret = hdc3020_read_high_peak_t(data, val);
-			if (ret < 0)
-				return ret;
-		} else {
-			ret = hdc3020_read_high_peak_rh(data, val);
-			if (ret < 0)
-				return ret;
-		}
+		if (chan->type == IIO_TEMP)
+			ret = hdc3020_read_be16(data, HDC3020_R_T_HIGH_AUTO);
+		else
+			ret = hdc3020_read_be16(data, HDC3020_R_RH_HIGH_AUTO);
+
+		if (ret < 0)
+			return ret;
+
+		*val = ret;
 		return IIO_VAL_INT;
 	}
 	case IIO_CHAN_INFO_TROUGH: {
 		guard(mutex)(&data->lock);
-		if (chan->type == IIO_TEMP) {
-			ret = hdc3020_read_low_peak_t(data, val);
-			if (ret < 0)
-				return ret;
-		} else {
-			ret = hdc3020_read_low_peak_rh(data, val);
-			if (ret < 0)
-				return ret;
-		}
+		if (chan->type == IIO_TEMP)
+			ret = hdc3020_read_be16(data, HDC3020_R_T_LOW_AUTO);
+		else
+			ret = hdc3020_read_be16(data, HDC3020_R_RH_LOW_AUTO);
+
+		if (ret < 0)
+			return ret;
+
+		*val = ret;
 		return IIO_VAL_INT;
 	}
 	case IIO_CHAN_INFO_SCALE:
@@ -352,23 +284,17 @@ static int hdc3020_update_heater(struct hdc3020_data *data, int val)
 	if (val < hdc3020_heater_vals[0] || val > hdc3020_heater_vals[2])
 		return -EINVAL;
 
-	buf[0] = HDC3020_HEATER_CMD_MSB;
+	if (!val)
+		hdc3020_exec_cmd(data, HDC3020_HEATER_DISABLE);
 
-	if (!val) {
-		buf[1] = HDC3020_HEATER_DISABLE;
-		return hdc3020_write_bytes(data, buf, 2);
-	}
-
-	buf[1] = HDC3020_HEATER_CONFIG;
+	put_unaligned_be16(HDC3020_HEATER_CONFIG, buf);
 	put_unaligned_be16(val & GENMASK(13, 0), &buf[2]);
 	buf[4] = crc8(hdc3020_crc8_table, buf + 2, 2, CRC8_INIT_VALUE);
 	ret = hdc3020_write_bytes(data, buf, 5);
 	if (ret < 0)
 		return ret;
 
-	buf[1] = HDC3020_HEATER_ENABLE;
-
-	return hdc3020_write_bytes(data, buf, 2);
+	return hdc3020_exec_cmd(data, HDC3020_HEATER_ENABLE);
 }
 
 static int hdc3020_write_raw(struct iio_dev *indio_dev,
@@ -397,7 +323,7 @@ static const struct iio_info hdc3020_info = {
 
 static void hdc3020_stop(void *data)
 {
-	hdc3020_write_bytes((struct hdc3020_data *)data, HDC3020_EXIT_AUTO, 2);
+	hdc3020_exec_cmd((struct hdc3020_data *)data, HDC3020_EXIT_AUTO);
 }
 
 static int hdc3020_probe(struct i2c_client *client)
@@ -425,7 +351,7 @@ static int hdc3020_probe(struct i2c_client *client)
 	indio_dev->channels = hdc3020_channels;
 	indio_dev->num_channels = ARRAY_SIZE(hdc3020_channels);
 
-	ret = hdc3020_write_bytes(data, HDC3020_S_AUTO_10HZ_MOD0, 2);
+	ret = hdc3020_exec_cmd(data, HDC3020_S_AUTO_10HZ_MOD0);
 	if (ret)
 		return dev_err_probe(&client->dev, ret,
 				     "Unable to set up measurement\n");