Introduce bme680 backport work in separate commit

linux_kernel_modules/bme680/bitfield.h

+/*
+ * Copyright (C) 2014 Felix Fietkau <nbd@nbd.name>
+ * Copyright (C) 2004 - 2009 Ivo van Doorn <IvDoorn@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _LINUX_BITFIELD_H
+#define _LINUX_BITFIELD_H
+
+#include <asm/byteorder.h>
+
+/*
+ * Bitfield access macros
+ *
+ * FIELD_{GET,PREP} macros take as first parameter shifted mask
+ * from which they extract the base mask and shift amount.
+ * Mask must be a compilation time constant.
+ *
+ * Example:
+ *
+ *  #define REG_FIELD_A  GENMASK(6, 0)
+ *  #define REG_FIELD_B  BIT(7)
+ *  #define REG_FIELD_C  GENMASK(15, 8)
+ *  #define REG_FIELD_D  GENMASK(31, 16)
+ *
+ * Get:
+ *  a = FIELD_GET(REG_FIELD_A, reg);
+ *  b = FIELD_GET(REG_FIELD_B, reg);
+ *
+ * Set:
+ *  reg = FIELD_PREP(REG_FIELD_A, 1) |
+ *	  FIELD_PREP(REG_FIELD_B, 0) |
+ *	  FIELD_PREP(REG_FIELD_C, c) |
+ *	  FIELD_PREP(REG_FIELD_D, 0x40);
+ *
+ * Modify:
+ *  reg &= ~REG_FIELD_C;
+ *  reg |= FIELD_PREP(REG_FIELD_C, c);
+ */
+
+#define __bf_shf(x) (__builtin_ffsll(x) - 1)
+
+/**
+ * FIELD_PREP() - prepare a bitfield element
+ * @_mask: shifted mask defining the field's length and position
+ * @_val:  value to put in the field
+ *
+ * FIELD_PREP() masks and shifts up the value.  The result should
+ * be combined with other fields of the bitfield using logical OR.
+ */
+#define FIELD_PREP(_mask, _val)						\
+	({								\
+		((typeof(_mask))(_val) << __bf_shf(_mask)) & (_mask);	\
+	})
+
+/**
+ * FIELD_GET() - extract a bitfield element
+ * @_mask: shifted mask defining the field's length and position
+ * @_reg:  value of entire bitfield
+ *
+ * FIELD_GET() extracts the field specified by @_mask from the
+ * bitfield passed in as @_reg by masking and shifting it down.
+ */
+#define FIELD_GET(_mask, _reg)						\
+	({								\
+		(typeof(_mask))(((_reg) & (_mask)) >> __bf_shf(_mask));	\
+	})
+
+#endif

linux_kernel_modules/bme680/bme680-i2c.mdef

+cflags:
+{
+    // This driver depends on IIO
+    -DCONFIG_IIO
+    -DCONFIG_IIO_BUFFER
+    -DCONFIG_IIO_TRIGGERRED_BUFFER
+    -DDEBUG
+    -DREGMAP
+    -DREGMAP_I2C
+}
+
+sources:
+{
+    bme680_i2c.c
+    bme680_core.c
+}
+
+requires:
+{
+    kernelModules:
+    {
+#if ${MANGOH_KERNEL_LACKS_IIO} = 1
+        $CURDIR/../iio/iio
+#endif // MANGOH_KERNEL_LACKS_IIO
+    }
+}

linux_kernel_modules/bme680/bme680_core.c

@@ -9,16 +9,22 @@
  * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BME680-DS001-00.pdf
  */
 #include <linux/acpi.h>
-#include <linux/bitfield.h>
+#include "bitfield.h"
 #include <linux/device.h>
 #include <linux/module.h>
 #include <linux/log2.h>
 #include <linux/regmap.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
-
+#include <linux/version.h>
 #include "bme680.h"
 
+#define regmap_write_bits regmap_update_bits
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 2, 0)
+#define IIO_SUPPORTS_OVERSAMPLING_RATIO
+#endif
+
 struct bme680_calib {
 	u16 par_t1;
 	s16 par_t2;
@@ -72,18 +78,24 @@ EXPORT_SYMBOL(bme680_regmap_config);
 static const struct iio_chan_spec bme680_channels[] = {
 	{
 		.type = IIO_TEMP,
-		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
-				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED)
+#ifdef IIO_SUPPORTS_OVERSAMPLING_RATIO
+				    | BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+#endif
 	},
 	{
 		.type = IIO_PRESSURE,
-		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
-				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED)
+#ifdef IIO_SUPPORTS_OVERSAMPLING_RATIO
+				    | BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+#endif
 	},
 	{
 		.type = IIO_HUMIDITYRELATIVE,
-		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
-				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED)
+#ifdef IIO_SUPPORTS_OVERSAMPLING_RATIO
+				    | BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+#endif
 	},
 	{
 		.type = IIO_RESISTANCE,
@@ -771,6 +783,7 @@ static int bme680_read_raw(struct iio_dev *indio_dev,
 		default:
 			return -EINVAL;
 		}
+#ifdef IIO_SUPPORTS_OVERSAMPLING_RATIO
 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 		switch (chan->type) {
 		case IIO_TEMP:
@@ -785,26 +798,32 @@ static int bme680_read_raw(struct iio_dev *indio_dev,
 		default:
 			return -EINVAL;
 		}
+#endif
 	default:
 		return -EINVAL;
 	}
 }
 
+#ifdef IIO_SUPPORTS_OVERSAMPLING_RATIO
 static bool bme680_is_valid_oversampling(int rate)
 {
 	return (rate > 0 && rate <= 16 && is_power_of_2(rate));
 }
+#endif
 
 static int bme680_write_raw(struct iio_dev *indio_dev,
 			    struct iio_chan_spec const *chan,
 			    int val, int val2, long mask)
 {
+#ifdef IIO_SUPPORTS_OVERSAMPLING_RATIO
 	struct bme680_data *data = iio_priv(indio_dev);
+#endif
 
 	if (val2 != 0)
 		return -EINVAL;
 
 	switch (mask) {
+#ifdef IIO_SUPPORTS_OVERSAMPLING_RATIO
 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 	{
 		if (!bme680_is_valid_oversampling(val))
@@ -826,18 +845,23 @@ static int bme680_write_raw(struct iio_dev *indio_dev,
 
 		return bme680_chip_config(data);
 	}
+#endif
 	default:
 		return -EINVAL;
 	}
 }
 
+#ifdef IIO_SUPPORTS_OVERSAMPLING_RATIO
 static const char bme680_oversampling_ratio_show[] = "1 2 4 8 16";
 
 static IIO_CONST_ATTR(oversampling_ratio_available,
 		      bme680_oversampling_ratio_show);
+#endif
 
 static struct attribute *bme680_attributes[] = {
+#ifdef IIO_SUPPORTS_OVERSAMPLING_RATIO
 	&iio_const_attr_oversampling_ratio_available.dev_attr.attr,
+#endif
 	NULL,
 };