From 59d41669b9b573b64e29187cf209abd81bafe045 Mon Sep 17 00:00:00 2001
From: "Peter A. Bigot" <pab@pabigot.com>
Date: Tue, 20 Nov 2018 06:05:38 -0600
Subject: [PATCH] drivers: sensor: ccs811: make measurement drive mode
 configurable

Allow application to choose the measurement rate.

Measurement mode 4 (250 ms rate) is not supported because it we have no
support for processing the raw data it produces.

Signed-off-by: Peter A. Bigot <pab@pabigot.com>
---
 drivers/sensor/ccs811/Kconfig  | 28 +++++++++++++++++++++++++++-
 drivers/sensor/ccs811/ccs811.c | 24 ++++++++++++++++++++----
 2 files changed, 47 insertions(+), 5 deletions(-)

diff --git a/drivers/sensor/ccs811/Kconfig b/drivers/sensor/ccs811/Kconfig
index 51b369c0c1f..0b160a72a1b 100644
--- a/drivers/sensor/ccs811/Kconfig
+++ b/drivers/sensor/ccs811/Kconfig
@@ -1,10 +1,36 @@
 # CCS811 Digital Gas sensor configuration options
 
 # Copyright (c) 2018 Linaro Ltd.
+# Copyright (c) 2018 Peter Bigot Consulting, LLC
+#
 # SPDX-License-Identifier: Apache-2.0
 
-config CCS811
+menuconfig CCS811
 	bool "CCS811 Digital Gas Sensor"
 	depends on I2C && HAS_DTS_I2C
 	help
 	  Enable driver for CCS811 Gas sensors.
+
+if CCS811
+
+choice CCS811_DRIVE_MODE
+	prompt "Measurement drive mode"
+	default CCS811_DRIVE_MODE_1
+	help
+	  Specifies the measurement rate used by the driver.
+
+config CCS811_DRIVE_MODE_0
+	bool "Measurements disabled"
+
+config CCS811_DRIVE_MODE_1
+	bool "Measurement every second"
+
+config CCS811_DRIVE_MODE_2
+	bool "Measurement every ten seconds"
+
+config CCS811_DRIVE_MODE_3
+	bool "Measurement every sixty seconds"
+
+endchoice
+
+endif # CCS811
diff --git a/drivers/sensor/ccs811/ccs811.c b/drivers/sensor/ccs811/ccs811.c
index 116c46f0060..2c21852c948 100644
--- a/drivers/sensor/ccs811/ccs811.c
+++ b/drivers/sensor/ccs811/ccs811.c
@@ -37,12 +37,20 @@ static void set_wake(struct ccs811_data *drv_data, bool enable)
 static int ccs811_sample_fetch(struct device *dev, enum sensor_channel chan)
 {
 	struct ccs811_data *drv_data = dev->driver_data;
-	int tries = 11;
+	int tries;
 	u16_t buf[4];
 	u8_t status;
 	int rv = -EIO;
 
-	/* Check data ready flag for the measurement interval of 1 seconds */
+	/* Check data ready flag for the measurement interval */
+#ifdef CONFIG_CCS811_DRIVE_MODE_1
+	tries = 11;
+#elif defined(CONFIG_CCS811_DRIVE_MODE_2)
+	tries = 101;
+#elif defined(CONFIG_CCS811_DRIVE_MODE_3)
+	tries = 601;
+#endif
+
 	while (tries-- > 0) {
 		set_wake(drv_data, true);
 		if (i2c_reg_read_byte(drv_data->i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
@@ -258,10 +266,18 @@ int ccs811_init(struct device *dev)
 		goto out;
 	}
 
-	/* Set Measurement mode for 1 second */
+	/* Configure measurement mode */
+	u8_t meas_mode = 0;
+#ifdef CONFIG_CCS811_DRIVE_MODE_1
+	meas_mode = 0x10;
+#elif defined(CONFIG_CCS811_DRIVE_MODE_2)
+	meas_mode = 0x20;
+#elif defined(CONFIG_CCS811_DRIVE_MODE_3)
+	meas_mode = 0x30;
+#endif
 	if (i2c_reg_write_byte(drv_data->i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
 			       CCS811_REG_MEAS_MODE,
-			       CCS811_MODE_IAQ_1SEC) < 0) {
+			       meas_mode) < 0) {
 		LOG_ERR("Failed to set Measurement mode");
 		ret = -EIO;
 		goto out;