regmap: Add regmap_fields APIs

Current Linux kernel is supporting regmap_field method
and it is very useful feature.
It needs one regmap_filed for one register access.

OTOH, there is multi port device which
has many same registers in the market.
The difference for each register access is
only its address offset.

Current API needs many regmap_field for such device,
but it is not good.
This patch adds new regmap_fileds API which can care
about multi port/offset access via regmap.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/base/regmap/internal.h

@@ -179,6 +179,9 @@ struct regmap_field {
 	/* lsb */
 	unsigned int shift;
 	unsigned int reg;
+
+	unsigned int id_size;
+	unsigned int id_offset;
 };
 
 #ifdef CONFIG_DEBUG_FS

drivers/base/regmap/regmap.c

@@ -821,6 +821,8 @@ static void regmap_field_init(struct regmap_field *rm_field,
 	rm_field->reg = reg_field.reg;
 	rm_field->shift = reg_field.lsb;
 	rm_field->mask = ((BIT(field_bits) - 1) << reg_field.lsb);
+	rm_field->id_size = reg_field.id_size;
+	rm_field->id_offset = reg_field.id_offset;
 }
 
 /**
@@ -1389,6 +1391,54 @@ int regmap_field_update_bits(struct regmap_field *field, unsigned int mask, unsi
 }
 EXPORT_SYMBOL_GPL(regmap_field_update_bits);
 
+/**
+ * regmap_fields_write(): Write a value to a single register field with port ID
+ *
+ * @field: Register field to write to
+ * @id: port ID
+ * @val: Value to be written
+ *
+ * A value of zero will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+int regmap_fields_write(struct regmap_field *field, unsigned int id,
+			unsigned int val)
+{
+	if (id >= field->id_size)
+		return -EINVAL;
+
+	return regmap_update_bits(field->regmap,
+				  field->reg + (field->id_offset * id),
+				  field->mask, val << field->shift);
+}
+EXPORT_SYMBOL_GPL(regmap_fields_write);
+
+/**
+ * regmap_fields_update_bits():	Perform a read/modify/write cycle
+ *                              on the register field
+ *
+ * @field: Register field to write to
+ * @id: port ID
+ * @mask: Bitmask to change
+ * @val: Value to be written
+ *
+ * A value of zero will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+int regmap_fields_update_bits(struct regmap_field *field,  unsigned int id,
+			      unsigned int mask, unsigned int val)
+{
+	if (id >= field->id_size)
+		return -EINVAL;
+
+	mask = (mask << field->shift) & field->mask;
+
+	return regmap_update_bits(field->regmap,
+				  field->reg + (field->id_offset * id),
+				  mask, val << field->shift);
+}
+EXPORT_SYMBOL_GPL(regmap_fields_update_bits);
+
 /*
  * regmap_bulk_write(): Write multiple registers to the device
  *
@@ -1696,6 +1746,39 @@ int regmap_field_read(struct regmap_field *field, unsigned int *val)
 }
 EXPORT_SYMBOL_GPL(regmap_field_read);
 
+/**
+ * regmap_fields_read(): Read a value to a single register field with port ID
+ *
+ * @field: Register field to read from
+ * @id: port ID
+ * @val: Pointer to store read value
+ *
+ * A value of zero will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+int regmap_fields_read(struct regmap_field *field, unsigned int id,
+		       unsigned int *val)
+{
+	int ret;
+	unsigned int reg_val;
+
+	if (id >= field->id_size)
+		return -EINVAL;
+
+	ret = regmap_read(field->regmap,
+			  field->reg + (field->id_offset * id),
+			  &reg_val);
+	if (ret != 0)
+		return ret;
+
+	reg_val &= field->mask;
+	reg_val >>= field->shift;
+	*val = reg_val;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_fields_read);
+
 /**
  * regmap_bulk_read(): Read multiple registers from the device
  *

include/linux/regmap.h

@@ -425,11 +425,15 @@ bool regmap_reg_in_ranges(unsigned int reg,
  * @reg: Offset of the register within the regmap bank
  * @lsb: lsb of the register field.
  * @reg: msb of the register field.
+ * @id_size: port size if it has some ports
+ * @id_offset: address offset for each ports
  */
 struct reg_field {
 	unsigned int reg;
 	unsigned int lsb;
 	unsigned int msb;
+	unsigned int id_size;
+	unsigned int id_offset;
 };
 
 #define REG_FIELD(_reg, _lsb, _msb) {		\
@@ -451,6 +455,13 @@ int regmap_field_write(struct regmap_field *field, unsigned int val);
 int regmap_field_update_bits(struct regmap_field *field,
 			     unsigned int mask, unsigned int val);
 
+int regmap_fields_write(struct regmap_field *field, unsigned int id,
+			unsigned int val);
+int regmap_fields_read(struct regmap_field *field, unsigned int id,
+		       unsigned int *val);
+int regmap_fields_update_bits(struct regmap_field *field,  unsigned int id,
+			      unsigned int mask, unsigned int val);
+
 /**
  * Description of an IRQ for the generic regmap irq_chip.
  *