[RFC 1/4] counter: Simplify the count_read and count_write callbacks

[William Breathitt Gray]

The count_read and count_write callbacks are simplified to pass val as
unsigned long rather than as an opaque data structure. The opaque
counter_count_read_value and counter_count_write_value structures,
counter_count_value_type enum, and relevant counter_count_read_value_set
and counter_count_write_value_get functions, are removed as they are no
longer used.

Signed-off-by: William Breathitt Gray <vilhelm.gray@xxxxxxxxx>
---
 drivers/counter/counter.c | 66 +++++----------------------------------
 include/linux/counter.h   | 43 +++----------------------
 2 files changed, 12 insertions(+), 97 deletions(-)

diff --git a/drivers/counter/counter.c b/drivers/counter/counter.c
index 106bc7180cd8..1d08f1437b1b 100644
--- a/drivers/counter/counter.c
+++ b/drivers/counter/counter.c
@@ -246,60 +246,6 @@ void counter_signal_read_value_set(struct counter_signal_read_value *const val,
 }
 EXPORT_SYMBOL_GPL(counter_signal_read_value_set);
 
-/**
- * counter_count_read_value_set - set counter_count_read_value data
- * @val:	counter_count_read_value structure to set
- * @type:	property Count data represents
- * @data:	Count data
- *
- * This function sets an opaque counter_count_read_value structure with the
- * provided Count data.
- */
-void counter_count_read_value_set(struct counter_count_read_value *const val,
-				  const enum counter_count_value_type type,
-				  void *const data)
-{
-	switch (type) {
-	case COUNTER_COUNT_POSITION:
-		val->len = sprintf(val->buf, "%lu\n", *(unsigned long *)data);
-		break;
-	default:
-		val->len = 0;
-	}
-}
-EXPORT_SYMBOL_GPL(counter_count_read_value_set);
-
-/**
- * counter_count_write_value_get - get counter_count_write_value data
- * @data:	Count data
- * @type:	property Count data represents
- * @val:	counter_count_write_value structure containing data
- *
- * This function extracts Count data from the provided opaque
- * counter_count_write_value structure and stores it at the address provided by
- * @data.
- *
- * RETURNS:
- * 0 on success, negative error number on failure.
- */
-int counter_count_write_value_get(void *const data,
-				  const enum counter_count_value_type type,
-				  const struct counter_count_write_value *const val)
-{
-	int err;
-
-	switch (type) {
-	case COUNTER_COUNT_POSITION:
-		err = kstrtoul(val->buf, 0, data);
-		if (err)
-			return err;
-		break;
-	}
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(counter_count_write_value_get);
-
 struct counter_attr_parm {
 	struct counter_device_attr_group *group;
 	const char *prefix;
@@ -788,13 +734,13 @@ static ssize_t counter_count_show(struct device *dev,
 	const struct counter_count_unit *const component = devattr->component;
 	struct counter_count *const count = component->count;
 	int err;
-	struct counter_count_read_value val = { .buf = buf };
+	unsigned long val;
 
 	err = counter->ops->count_read(counter, count, &val);
 	if (err)
 		return err;
 
-	return val.len;
+	return sprintf(buf, "%lu\n", val);
 }
 
 static ssize_t counter_count_store(struct device *dev,
@@ -806,9 +752,13 @@ static ssize_t counter_count_store(struct device *dev,
 	const struct counter_count_unit *const component = devattr->component;
 	struct counter_count *const count = component->count;
 	int err;
-	struct counter_count_write_value val = { .buf = buf };
+	unsigned long val;
+
+	err = kstrtoul(buf, 0, &val);
+	if (err)
+		return err;
 
-	err = counter->ops->count_write(counter, count, &val);
+	err = counter->ops->count_write(counter, count, val);
 	if (err)
 		return err;
 
diff --git a/include/linux/counter.h b/include/linux/counter.h
index a061cdcdef7c..7e40796598a6 100644
--- a/include/linux/counter.h
+++ b/include/linux/counter.h
@@ -300,24 +300,6 @@ struct counter_signal_read_value {
 	size_t len;
 };
 
-/**
- * struct counter_count_read_value - Opaque Count read value
- * @buf:	string representation of Count read value
- * @len:	length of string in @buf
- */
-struct counter_count_read_value {
-	char *buf;
-	size_t len;
-};
-
-/**
- * struct counter_count_write_value - Opaque Count write value
- * @buf:	string representation of Count write value
- */
-struct counter_count_write_value {
-	const char *buf;
-};
-
 /**
  * struct counter_ops - Callbacks from driver
  * @signal_read:	optional read callback for Signal attribute. The read
@@ -328,15 +310,10 @@ struct counter_count_write_value {
  *			signal_read callback.
  * @count_read:		optional read callback for Count attribute. The read
  *			value of the respective Count should be passed back via
- *			the val parameter. val points to an opaque type which
- *			should be set only by calling the
- *			counter_count_read_value_set function from within the
- *			count_read callback.
+ *			the val parameter.
  * @count_write:	optional write callback for Count attribute. The write
  *			value for the respective Count is passed in via the val
- *			parameter. val points to an opaque type which should be
- *			accessed only by calling the
- *			counter_count_write_value_get function.
+ *			parameter.
  * @function_get:	function to get the current count function mode. Returns
  *			0 on success and negative error code on error. The index
  *			of the respective Count's returned function mode should
@@ -357,11 +334,9 @@ struct counter_ops {
 			   struct counter_signal *signal,
 			   struct counter_signal_read_value *val);
 	int (*count_read)(struct counter_device *counter,
-			  struct counter_count *count,
-			  struct counter_count_read_value *val);
+			  struct counter_count *count, unsigned long *val);
 	int (*count_write)(struct counter_device *counter,
-			   struct counter_count *count,
-			   struct counter_count_write_value *val);
+			   struct counter_count *count, unsigned long val);
 	int (*function_get)(struct counter_device *counter,
 			    struct counter_count *count, size_t *function);
 	int (*function_set)(struct counter_device *counter,
@@ -486,19 +461,9 @@ enum counter_signal_value_type {
 	COUNTER_SIGNAL_LEVEL = 0
 };
 
-enum counter_count_value_type {
-	COUNTER_COUNT_POSITION = 0,
-};
-
 void counter_signal_read_value_set(struct counter_signal_read_value *const val,
 				   const enum counter_signal_value_type type,
 				   void *const data);
-void counter_count_read_value_set(struct counter_count_read_value *const val,
-				  const enum counter_count_value_type type,
-				  void *const data);
-int counter_count_write_value_get(void *const data,
-				  const enum counter_count_value_type type,
-				  const struct counter_count_write_value *const val);
 
 int counter_register(struct counter_device *const counter);
 void counter_unregister(struct counter_device *const counter);
-- 
2.23.0