[PATCH v2 3/6] iio: adis: Add adis_update_bits() APIs

["Nuno Sá" <nuno.sa@analog.com>]

This patch adds a `regmap_update_bits()` like API to the ADIS library.
It provides locked and unlocked variant.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
---
Changes in v2:
 * Add BUILD_BUG_ON() to avoid invalid types.

 drivers/iio/imu/adis.c       | 26 ++++++++++++++++
 include/linux/iio/imu/adis.h | 59 ++++++++++++++++++++++++++++++++++++
 2 files changed, 85 insertions(+)

diff --git a/drivers/iio/imu/adis.c b/drivers/iio/imu/adis.c
index a8afd01de4f3..fa0ee35d96f0 100644
--- a/drivers/iio/imu/adis.c
+++ b/drivers/iio/imu/adis.c
@@ -223,6 +223,32 @@ int __adis_read_reg(struct adis *adis, unsigned int reg,
 	return ret;
 }
 EXPORT_SYMBOL_GPL(__adis_read_reg);
+/**
+ * __adis_update_bits_base() - ADIS Update bits function - Unlocked version
+ * @adis: The adis device
+ * @reg: The address of the lower of the two registers
+ * @mask: Bitmask to change
+ * @val: Value to be written
+ * @size: Size of the register to update
+ *
+ * Updates the desired bits of @reg in accordance with @mask and @val.
+ */
+int __adis_update_bits_base(struct adis *adis, unsigned int reg, const u32 mask,
+			    const u32 val, u8 size)
+{
+	int ret;
+	u32 __val;
+
+	ret = __adis_read_reg(adis, reg, &__val, size);
+	if (ret)
+		return ret;
+
+	__val &= ~mask;
+	__val |= val & mask;
+
+	return __adis_write_reg(adis, reg, __val, size);
+}
+EXPORT_SYMBOL_GPL(__adis_update_bits_base);
 
 #ifdef CONFIG_DEBUG_FS
 
diff --git a/include/linux/iio/imu/adis.h b/include/linux/iio/imu/adis.h
index ed41c6b96d14..94031b3fc9d5 100644
--- a/include/linux/iio/imu/adis.h
+++ b/include/linux/iio/imu/adis.h
@@ -333,6 +333,65 @@ static inline int adis_read_reg_32(struct adis *adis, unsigned int reg,
 	return ret;
 }
 
+int __adis_update_bits_base(struct adis *adis, unsigned int reg, const u32 mask,
+			    const u32 val, u8 size);
+/**
+ * adis_update_bits_base() - ADIS Update bits function - Locked version
+ * @adis: The adis device
+ * @reg: The address of the lower of the two registers
+ * @mask: Bitmask to change
+ * @val: Value to be written
+ * @size: Size of the register to update
+ *
+ * Updates the desired bits of @reg in accordance with @mask and @val.
+ */
+static inline int adis_update_bits_base(struct adis *adis, unsigned int reg,
+					const u32 mask, const u32 val, u8 size)
+{
+	int ret;
+
+	mutex_lock(&adis->state_lock);
+	ret = __adis_update_bits_base(adis, reg, mask, val, size);
+	mutex_unlock(&adis->state_lock);
+	return ret;
+}
+
+/**
+ * adis_update_bits() - Wrapper macro for adis_update_bits_base - Locked version
+ * @adis: The adis device
+ * @reg: The address of the lower of the two registers
+ * @mask: Bitmask to change
+ * @val: Value to be written
+ *
+ * This macro evaluates the sizeof of @val at compile time and calls
+ * adis_update_bits_base() accordingly. Be aware that using MACROS/DEFINES for
+ * @val can lead to undesired behavior if the register to update is 16bit.
+ */
+#define adis_update_bits(adis, reg, mask, val) ({			\
+	BUILD_BUG_ON(sizeof(val) == 1 || sizeof(val) == 8);		\
+	__builtin_choose_expr(sizeof(val) == 4,				\
+		adis_update_bits_base(adis, reg, mask, val, 4),         \
+		adis_update_bits_base(adis, reg, mask, val, 2));	\
+})
+
+/**
+ * adis_update_bits() - Wrapper macro for adis_update_bits_base
+ * @adis: The adis device
+ * @reg: The address of the lower of the two registers
+ * @mask: Bitmask to change
+ * @val: Value to be written
+ *
+ * This macro evaluates the sizeof of @val at compile time and calls
+ * adis_update_bits_base() accordingly. Be aware that using MACROS/DEFINES for
+ * @val can lead to undesired behavior if the register to update is 16bit.
+ */
+#define __adis_update_bits(adis, reg, mask, val) ({			\
+	BUILD_BUG_ON(sizeof(val) == 1 || sizeof(val) == 8);		\
+	__builtin_choose_expr(sizeof(val) == 4,				\
+		__adis_update_bits_base(adis, reg, mask, val, 4),	\
+		__adis_update_bits_base(adis, reg, mask, val, 2));	\
+})
+
 int adis_enable_irq(struct adis *adis, bool enable);
 int __adis_check_status(struct adis *adis);
 int __adis_initial_startup(struct adis *adis);
-- 
2.25.1