[PATCH v4 1/6] iio: imu: adis: Add custom ops struct

[Robert Budai <robert.budai@analog.com>]

This patch introduces a custom ops struct letting users define
custom read and write functions. Some adis devices might define
a completely different spi protocol from the one used in the
default implementation.

Co-developed-by: Ramona Gradinariu <ramona.gradinariu@analog.com>
Signed-off-by: Ramona Gradinariu <ramona.gradinariu@analog.com>
Co-developed-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Robert Budai <robert.budai@analog.com>
---
 drivers/iio/imu/adis.c       | 16 +++++++++++++---
 include/linux/iio/imu/adis.h | 28 +++++++++++++++++++++-------
 2 files changed, 34 insertions(+), 10 deletions(-)

diff --git a/drivers/iio/imu/adis.c b/drivers/iio/imu/adis.c
index 494171844812..54915c7a3e76 100644
--- a/drivers/iio/imu/adis.c
+++ b/drivers/iio/imu/adis.c
@@ -223,13 +223,13 @@ int __adis_update_bits_base(struct adis *adis, unsigned int reg, const u32 mask,
 	int ret;
 	u32 __val;
 
-	ret = __adis_read_reg(adis, reg, &__val, size);
+	ret = adis->ops->read(adis, reg, &__val, size);
 	if (ret)
 		return ret;
 
 	__val = (__val & ~mask) | (val & mask);
 
-	return __adis_write_reg(adis, reg, __val, size);
+	return adis->ops->write(adis, reg, __val, size);
 }
 EXPORT_SYMBOL_NS_GPL(__adis_update_bits_base, "IIO_ADISLIB");
 
@@ -468,7 +468,7 @@ int adis_single_conversion(struct iio_dev *indio_dev,
 
 	guard(mutex)(&adis->state_lock);
 
-	ret = __adis_read_reg(adis, chan->address, &uval,
+	ret = adis->ops->read(adis, chan->address, &uval,
 			      chan->scan_type.storagebits / 8);
 	if (ret)
 		return ret;
@@ -488,6 +488,11 @@ int adis_single_conversion(struct iio_dev *indio_dev,
 }
 EXPORT_SYMBOL_NS_GPL(adis_single_conversion, "IIO_ADISLIB");
 
+static const struct adis_ops adis_default_ops = {
+	.read = __adis_read_reg,
+	.write = __adis_write_reg,
+};
+
 /**
  * adis_init() - Initialize adis device structure
  * @adis:	The adis device
@@ -517,6 +522,11 @@ int adis_init(struct adis *adis, struct iio_dev *indio_dev,
 
 	adis->spi = spi;
 	adis->data = data;
+	if (!adis->ops->write && !adis->ops->read)
+		adis->ops = &adis_default_ops;
+	else if (!adis->ops->write || !adis->ops->read)
+		return -EINVAL;
+
 	iio_device_set_drvdata(indio_dev, adis);
 
 	if (data->has_paging) {
diff --git a/include/linux/iio/imu/adis.h b/include/linux/iio/imu/adis.h
index 4bb98d9731de..89cfa75ae9ea 100644
--- a/include/linux/iio/imu/adis.h
+++ b/include/linux/iio/imu/adis.h
@@ -94,6 +94,18 @@ struct adis_data {
 	unsigned int burst_max_speed_hz;
 };
 
+/**
+ * struct adis_ops: Custom ops for adis devices.
+ * @write: Custom spi write implementation.
+ * @read: Custom spi read implementation.
+ */
+struct adis_ops {
+	int (*write)(struct adis *adis, unsigned int reg, unsigned int value,
+		     unsigned int size);
+	int (*read)(struct adis *adis, unsigned int reg, unsigned int *value,
+		    unsigned int size);
+};
+
 /**
  * struct adis - ADIS device instance data
  * @spi: Reference to SPI device which owns this ADIS IIO device
@@ -101,6 +113,7 @@ struct adis_data {
  * @data: ADIS chip variant specific data
  * @burst_extra_len: Burst extra length. Should only be used by devices that can
  *		     dynamically change their burst mode length.
+ * @ops: ops struct for custom read and write functions
  * @state_lock: Lock used by the device to protect state
  * @msg: SPI message object
  * @xfer: SPI transfer objects to be used for a @msg
@@ -116,6 +129,7 @@ struct adis {
 
 	const struct adis_data	*data;
 	unsigned int		burst_extra_len;
+	const struct adis_ops	*ops;
 	/**
 	 * The state_lock is meant to be used during operations that require
 	 * a sequence of SPI R/W in order to protect the SPI transfer
@@ -168,7 +182,7 @@ int __adis_read_reg(struct adis *adis, unsigned int reg,
 static inline int __adis_write_reg_8(struct adis *adis, unsigned int reg,
 				     u8 val)
 {
-	return __adis_write_reg(adis, reg, val, 1);
+	return adis->ops->write(adis, reg, val, 1);
 }
 
 /**
@@ -180,7 +194,7 @@ static inline int __adis_write_reg_8(struct adis *adis, unsigned int reg,
 static inline int __adis_write_reg_16(struct adis *adis, unsigned int reg,
 				      u16 val)
 {
-	return __adis_write_reg(adis, reg, val, 2);
+	return adis->ops->write(adis, reg, val, 2);
 }
 
 /**
@@ -192,7 +206,7 @@ static inline int __adis_write_reg_16(struct adis *adis, unsigned int reg,
 static inline int __adis_write_reg_32(struct adis *adis, unsigned int reg,
 				      u32 val)
 {
-	return __adis_write_reg(adis, reg, val, 4);
+	return adis->ops->write(adis, reg, val, 4);
 }
 
 /**
@@ -207,7 +221,7 @@ static inline int __adis_read_reg_16(struct adis *adis, unsigned int reg,
 	unsigned int tmp;
 	int ret;
 
-	ret = __adis_read_reg(adis, reg, &tmp, 2);
+	ret = adis->ops->read(adis, reg, &tmp, 2);
 	if (ret == 0)
 		*val = tmp;
 
@@ -226,7 +240,7 @@ static inline int __adis_read_reg_32(struct adis *adis, unsigned int reg,
 	unsigned int tmp;
 	int ret;
 
-	ret = __adis_read_reg(adis, reg, &tmp, 4);
+	ret = adis->ops->read(adis, reg, &tmp, 4);
 	if (ret == 0)
 		*val = tmp;
 
@@ -244,7 +258,7 @@ static inline int adis_write_reg(struct adis *adis, unsigned int reg,
 				 unsigned int val, unsigned int size)
 {
 	guard(mutex)(&adis->state_lock);
-	return __adis_write_reg(adis, reg, val, size);
+	return adis->ops->write(adis, reg, val, size);
 }
 
 /**
@@ -258,7 +272,7 @@ static int adis_read_reg(struct adis *adis, unsigned int reg,
 			 unsigned int *val, unsigned int size)
 {
 	guard(mutex)(&adis->state_lock);
-	return __adis_read_reg(adis, reg, val, size);
+	return adis->ops->read(adis, reg, val, size);
 }
 
 /**
-- 
2.34.1