iio: refactor info mask and ext_info attribute creation.

Introduce an enum to specify whether the attribute is separate or
shared.

Factor out the bitmap handling for loop into a separate function.

Tidy up error handling and add a NULL assignment to squish a false
positive warning from GCC.

Change ext_info shared type from boolean to enum and update in all
drivers.

Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>

drivers/iio/dac/ad5064.c

@@ -285,8 +285,9 @@ static const struct iio_chan_spec_ext_info ad5064_ext_info[] = {
 		.name = "powerdown",
 		.read = ad5064_read_dac_powerdown,
 		.write = ad5064_write_dac_powerdown,
+		.shared = IIO_SEPARATE,
 	},
-	IIO_ENUM("powerdown_mode", false, &ad5064_powerdown_mode_enum),
+	IIO_ENUM("powerdown_mode", IIO_SEPARATE, &ad5064_powerdown_mode_enum),
 	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5064_powerdown_mode_enum),
 	{ },
 };

drivers/iio/dac/ad5380.c

@@ -247,8 +247,10 @@ static struct iio_chan_spec_ext_info ad5380_ext_info[] = {
 		.name = "powerdown",
 		.read = ad5380_read_dac_powerdown,
 		.write = ad5380_write_dac_powerdown,
+		.shared = IIO_SEPARATE,
 	},
-	IIO_ENUM("powerdown_mode", true, &ad5380_powerdown_mode_enum),
+	IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
+		 &ad5380_powerdown_mode_enum),
 	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5380_powerdown_mode_enum),
 	{ },
 };

drivers/iio/dac/ad5446.c

@@ -132,8 +132,9 @@ static const struct iio_chan_spec_ext_info ad5446_ext_info_powerdown[] = {
 		.name = "powerdown",
 		.read = ad5446_read_dac_powerdown,
 		.write = ad5446_write_dac_powerdown,
+		.shared = IIO_SEPARATE,
 	},
-	IIO_ENUM("powerdown_mode", false, &ad5446_powerdown_mode_enum),
+	IIO_ENUM("powerdown_mode", IIO_SEPARATE, &ad5446_powerdown_mode_enum),
 	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5446_powerdown_mode_enum),
 	{ },
 };

drivers/iio/dac/ad5504.c

@@ -248,8 +248,10 @@ static const struct iio_chan_spec_ext_info ad5504_ext_info[] = {
 		.name = "powerdown",
 		.read = ad5504_read_dac_powerdown,
 		.write = ad5504_write_dac_powerdown,
+		.shared = IIO_SEPARATE,
 	},
-	IIO_ENUM("powerdown_mode", true, &ad5504_powerdown_mode_enum),
+	IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
+		 &ad5504_powerdown_mode_enum),
 	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5504_powerdown_mode_enum),
 	{ },
 };

drivers/iio/dac/ad5624r_spi.c

@@ -163,8 +163,10 @@ static const struct iio_chan_spec_ext_info ad5624r_ext_info[] = {
 		.name = "powerdown",
 		.read = ad5624r_read_dac_powerdown,
 		.write = ad5624r_write_dac_powerdown,
+		.shared = IIO_SEPARATE,
 	},
-	IIO_ENUM("powerdown_mode", true, &ad5624r_powerdown_mode_enum),
+	IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
+		 &ad5624r_powerdown_mode_enum),
 	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5624r_powerdown_mode_enum),
 	{ },
 };

drivers/iio/dac/ad5686.c

@@ -264,8 +264,9 @@ static const struct iio_chan_spec_ext_info ad5686_ext_info[] = {
 		.name = "powerdown",
 		.read = ad5686_read_dac_powerdown,
 		.write = ad5686_write_dac_powerdown,
+		.shared = IIO_SEPARATE,
 	},
-	IIO_ENUM("powerdown_mode", false, &ad5686_powerdown_mode_enum),
+	IIO_ENUM("powerdown_mode", IIO_SEPARATE, &ad5686_powerdown_mode_enum),
 	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5686_powerdown_mode_enum),
 	{ },
 };

drivers/iio/dac/ad5755.c

@@ -386,6 +386,7 @@ static const struct iio_chan_spec_ext_info ad5755_ext_info[] = {
 		.name = "powerdown",
 		.read = ad5755_read_powerdown,
 		.write = ad5755_write_powerdown,
+		.shared = IIO_SEPARATE,
 	},
 	{ },
 };

drivers/iio/dac/ad5791.c

@@ -287,11 +287,12 @@ static int ad5791_read_raw(struct iio_dev *indio_dev,
 static const struct iio_chan_spec_ext_info ad5791_ext_info[] = {
 	{
 		.name = "powerdown",
-		.shared = true,
+		.shared = IIO_SHARED_BY_TYPE,
 		.read = ad5791_read_dac_powerdown,
 		.write = ad5791_write_dac_powerdown,
 	},
-	IIO_ENUM("powerdown_mode", true, &ad5791_powerdown_mode_enum),
+	IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
+		 &ad5791_powerdown_mode_enum),
 	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5791_powerdown_mode_enum),
 	{ },
 };

drivers/iio/dac/ad7303.c

@@ -169,6 +169,7 @@ static const struct iio_chan_spec_ext_info ad7303_ext_info[] = {
 		.name = "powerdown",
 		.read = ad7303_read_dac_powerdown,
 		.write = ad7303_write_dac_powerdown,
+		.shared = IIO_SEPARATE,
 	},
 	{ },
 };

drivers/iio/dac/mcp4725.c

@@ -195,8 +195,9 @@ static const struct iio_chan_spec_ext_info mcp4725_ext_info[] = {
 		.name = "powerdown",
 		.read = mcp4725_read_powerdown,
 		.write = mcp4725_write_powerdown,
+		.shared = IIO_SEPARATE,
 	},
-	IIO_ENUM("powerdown_mode", false, &mcp4725_powerdown_mode_enum),
+	IIO_ENUM("powerdown_mode", IIO_SEPARATE, &mcp4725_powerdown_mode_enum),
 	IIO_ENUM_AVAILABLE("powerdown_mode", &mcp4725_powerdown_mode_enum),
 	{ },
 };

drivers/iio/frequency/adf4350.c

@@ -351,6 +351,7 @@ static ssize_t adf4350_read(struct iio_dev *indio_dev,
 	.read = adf4350_read, \
 	.write = adf4350_write, \
 	.private = _ident, \
+	.shared = IIO_SEPARATE, \
 }
 
 static const struct iio_chan_spec_ext_info adf4350_ext_info[] = {

drivers/iio/iio_core.h

@@ -30,7 +30,7 @@ int __iio_add_chan_devattr(const char *postfix,
 						const char *buf,
 						size_t len),
 			   u64 mask,
-			   bool generic,
+			   enum iio_shared_by shared_by,
 			   struct device *dev,
 			   struct list_head *attr_list);
 

drivers/iio/industrialio-buffer.c

@@ -208,7 +208,7 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
 				     &iio_show_scan_index,
 				     NULL,
 				     0,
-				     0,
+				     IIO_SEPARATE,
 				     &indio_dev->dev,
 				     &buffer->scan_el_dev_attr_list);
 	if (ret)

drivers/iio/industrialio-core.c

@@ -517,14 +517,15 @@ int __iio_device_attr_init(struct device_attribute *dev_attr,
 						struct device_attribute *attr,
 						const char *buf,
 						size_t len),
-			   bool generic)
+			   enum iio_shared_by shared_by)
 {
-	int ret;
-	char *name_format, *full_postfix;
+	int ret = 0;
+	char *name_format = NULL;
+	char *full_postfix;
 	sysfs_attr_init(&dev_attr->attr);
 
 	/* Build up postfix of <extend_name>_<modifier>_postfix */
-	if (chan->modified && !generic) {
+	if (chan->modified && (shared_by == IIO_SEPARATE)) {
 		if (chan->extend_name)
 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 						 iio_modifier_names[chan
@@ -545,41 +546,48 @@ int __iio_device_attr_init(struct device_attribute *dev_attr,
 						 chan->extend_name,
 						 postfix);
 	}
-	if (full_postfix == NULL) {
-		ret = -ENOMEM;
-		goto error_ret;
-	}
+	if (full_postfix == NULL)
+		return -ENOMEM;
 
 	if (chan->differential) { /* Differential can not have modifier */
-		if (generic)
+		switch (shared_by) {
+		case IIO_SHARED_BY_TYPE:
 			name_format
 				= kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 					    iio_direction[chan->output],
 					    iio_chan_type_name_spec[chan->type],
 					    iio_chan_type_name_spec[chan->type],
 					    full_postfix);
-		else if (chan->indexed)
+			break;
+		case IIO_SEPARATE:
+			if (!chan->indexed) {
+				WARN_ON("Differential channels must be indexed\n");
+				ret = -EINVAL;
+				goto error_free_full_postfix;
+			}
 			name_format
-				= kasprintf(GFP_KERNEL, "%s_%s%d-%s%d_%s",
+				= kasprintf(GFP_KERNEL,
+					    "%s_%s%d-%s%d_%s",
 					    iio_direction[chan->output],
 					    iio_chan_type_name_spec[chan->type],
 					    chan->channel,
 					    iio_chan_type_name_spec[chan->type],
 					    chan->channel2,
 					    full_postfix);
-		else {
-			WARN_ON("Differential channels must be indexed\n");
-			ret = -EINVAL;
-			goto error_free_full_postfix;
+			break;
 		}
 	} else { /* Single ended */
-		if (generic)
+		switch (shared_by) {
+		case IIO_SHARED_BY_TYPE:
 			name_format
 				= kasprintf(GFP_KERNEL, "%s_%s_%s",
 					    iio_direction[chan->output],
 					    iio_chan_type_name_spec[chan->type],
 					    full_postfix);
-		else if (chan->indexed)
+			break;
+
+		case IIO_SEPARATE:
+			if (chan->indexed)
 				name_format
 					= kasprintf(GFP_KERNEL, "%s_%s%d_%s",
 						    iio_direction[chan->output],
@@ -592,6 +600,8 @@ int __iio_device_attr_init(struct device_attribute *dev_attr,
 						    iio_direction[chan->output],
 						    iio_chan_type_name_spec[chan->type],
 						    full_postfix);
+			break;
+		}
 	}
 	if (name_format == NULL) {
 		ret = -ENOMEM;
@@ -615,16 +625,11 @@ int __iio_device_attr_init(struct device_attribute *dev_attr,
 		dev_attr->attr.mode |= S_IWUSR;
 		dev_attr->store = writefunc;
 	}
-	kfree(name_format);
-	kfree(full_postfix);
-
-	return 0;
-
 error_free_name_format:
 	kfree(name_format);
 error_free_full_postfix:
 	kfree(full_postfix);
-error_ret:
+
 	return ret;
 }
 
@@ -643,7 +648,7 @@ int __iio_add_chan_devattr(const char *postfix,
 						const char *buf,
 						size_t len),
 			   u64 mask,
-			   bool generic,
+			   enum iio_shared_by shared_by,
 			   struct device *dev,
 			   struct list_head *attr_list)
 {
@@ -657,7 +662,7 @@ int __iio_add_chan_devattr(const char *postfix,
 	}
 	ret = __iio_device_attr_init(&iio_attr->dev_attr,
 				     postfix, chan,
-				     readfunc, writefunc, generic);
+				     readfunc, writefunc, shared_by);
 	if (ret)
 		goto error_iio_dev_attr_free;
 	iio_attr->c = chan;
@@ -665,7 +670,7 @@ int __iio_add_chan_devattr(const char *postfix,
 	list_for_each_entry(t, attr_list, l)
 		if (strcmp(t->dev_attr.attr.name,
 			   iio_attr->dev_attr.attr.name) == 0) {
-			if (!generic)
+			if (shared_by == IIO_SEPARATE)
 				dev_err(dev, "tried to double register : %s\n",
 					t->dev_attr.attr.name);
 			ret = -EBUSY;
@@ -683,45 +688,53 @@ error_ret:
 	return ret;
 }
 
+static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
+					 struct iio_chan_spec const *chan,
+					 enum iio_shared_by shared_by,
+					 const long *infomask)
+{
+	int i, ret, attrcount = 0;
+
+	for_each_set_bit(i, infomask, sizeof(infomask)*8) {
+		ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
+					     chan,
+					     &iio_read_channel_info,
+					     &iio_write_channel_info,
+					     i,
+					     shared_by,
+					     &indio_dev->dev,
+					     &indio_dev->channel_attr_list);
+		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
+			continue;
+		else if (ret < 0)
+			return ret;
+		attrcount++;
+	}
+
+	return attrcount;
+}
+
 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
 					struct iio_chan_spec const *chan)
 {
 	int ret, attrcount = 0;
-	int i;
 	const struct iio_chan_spec_ext_info *ext_info;
 
 	if (chan->channel < 0)
 		return 0;
-	for_each_set_bit(i, &chan->info_mask_separate, sizeof(long)*8) {
-		ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
-					     chan,
-					     &iio_read_channel_info,
-					     &iio_write_channel_info,
-					     i,
-					     0,
-					     &indio_dev->dev,
-					     &indio_dev->channel_attr_list);
+	ret = iio_device_add_info_mask_type(indio_dev, chan,
+					    IIO_SEPARATE,
+					    &chan->info_mask_separate);
 	if (ret < 0)
-			goto error_ret;
-		attrcount++;
-	}
-	for_each_set_bit(i, &chan->info_mask_shared_by_type, sizeof(long)*8) {
-		ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
-					     chan,
-					     &iio_read_channel_info,
-					     &iio_write_channel_info,
-					     i,
-					     1,
-					     &indio_dev->dev,
-					     &indio_dev->channel_attr_list);
-		if (ret == -EBUSY) {
-			ret = 0;
-			continue;
-		} else if (ret < 0) {
-			goto error_ret;
-		}
-		attrcount++;
-	}
+		return ret;
+	attrcount += ret;
+
+	ret = iio_device_add_info_mask_type(indio_dev, chan,
+					    IIO_SHARED_BY_TYPE,
+					    &chan->info_mask_shared_by_type);
+	if (ret < 0)
+		return ret;
+	attrcount += ret;
 
 	if (chan->ext_info) {
 		unsigned int i = 0;
@@ -741,15 +754,13 @@ static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
 				continue;
 
 			if (ret)
-				goto error_ret;
+				return ret;
 
 			attrcount++;
 		}
 	}
 
-	ret = attrcount;
-error_ret:
-	return ret;
+	return attrcount;
 }
 
 static void iio_device_remove_and_free_read_attr(struct iio_dev *indio_dev,

include/linux/iio/iio.h

@@ -39,6 +39,11 @@ enum iio_chan_info_enum {
 	IIO_CHAN_INFO_INT_TIME,
 };
 
+enum iio_shared_by {
+	IIO_SEPARATE,
+	IIO_SHARED_BY_TYPE
+};
+
 enum iio_endian {
 	IIO_CPU,
 	IIO_BE,
@@ -58,7 +63,7 @@ struct iio_dev;
  */
 struct iio_chan_spec_ext_info {
 	const char *name;
-	bool shared;
+	enum iio_shared_by shared;
 	ssize_t (*read)(struct iio_dev *, uintptr_t private,
 			struct iio_chan_spec const *, char *buf);
 	ssize_t (*write)(struct iio_dev *, uintptr_t private,
@@ -126,7 +131,7 @@ ssize_t iio_enum_write(struct iio_dev *indio_dev,
 #define IIO_ENUM_AVAILABLE(_name, _e) \
 { \
 	.name = (_name "_available"), \
-	.shared = true, \
+	.shared = IIO_SHARED_BY_TYPE, \
 	.read = iio_enum_available_read, \
 	.private = (uintptr_t)(_e), \
 }