[PATCH 1/5] iio: imu: adis: Add custom ops struct

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

From: Nuno Sá <nuno.sa@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>
---
 drivers/iio/imu/adis.c       | 21 ++++++++++++++++-----
 include/linux/iio/imu/adis.h | 30 +++++++++++++++++++++++-------
 2 files changed, 39 insertions(+), 12 deletions(-)

diff --git a/drivers/iio/imu/adis.c b/drivers/iio/imu/adis.c
index 99410733c1ca..504d18a36f90 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);
 
@@ -339,8 +339,11 @@ int __adis_reset(struct adis *adis)
 	int ret;
 	const struct adis_timeout *timeouts = adis->data->timeouts;
 
-	ret = __adis_write_reg_8(adis, adis->data->glob_cmd_reg,
-				 ADIS_GLOB_CMD_SW_RESET);
+	if (adis->ops->reset)
+		ret = adis->ops->reset(adis);
+	else
+		ret = __adis_write_reg_8(adis, adis->data->glob_cmd_reg,
+					 ADIS_GLOB_CMD_SW_RESET);
 	if (ret) {
 		dev_err(&adis->spi->dev, "Failed to reset device: %d\n", ret);
 		return ret;
@@ -468,7 +471,7 @@ 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 +491,11 @@ 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 +525,9 @@ 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;
+
 	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 e6a75356567a..7b589cc83380 100644
--- a/include/linux/iio/imu/adis.h
+++ b/include/linux/iio/imu/adis.h
@@ -94,6 +94,21 @@ 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.
+ * @reset: Custom sw reset implementation. The custom implementation does not
+ *	   need to sleep after the reset. It's done by the library already.
+ */
+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);
+	int (*reset)(struct adis *adis);
+};
+
 /**
  * struct adis - ADIS device instance data
  * @spi: Reference to SPI device which owns this ADIS IIO device
@@ -117,6 +132,7 @@ 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
@@ -169,7 +185,7 @@ 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);
 }
 
 /**
@@ -181,7 +197,7 @@ 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);
 }
 
 /**
@@ -193,7 +209,7 @@ 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);
 }
 
 /**
@@ -208,7 +224,7 @@ 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;
 
@@ -227,7 +243,7 @@ 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;
 
@@ -245,7 +261,7 @@ 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);
 }
 
 /**
@@ -259,7 +275,7 @@ 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