iio: adc: ad7606: Add support for software mode for ad7616

Support for ad7616 running in software was added. In order
to activate the software mode, HW_RNGSEL pins must be pulled low.
Oversampling and input ranges are now configured in corresponding
registers. Ad7616 has multiple scale options when it is configured
in software mode.
Also, in order to support multiple devices in software mode, the spi
calculation of registers address must be generic. Because
the length of address and bit which specifies the read/write operation is
different for every device, calculation of address was made generic.

Signed-off-by: Beniamin Bia <beniamin.bia@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/ad7606.h

@@ -8,14 +8,14 @@
 #ifndef IIO_ADC_AD7606_H_
 #define IIO_ADC_AD7606_H_
 
-#define AD760X_CHANNEL(num, mask) {				\
+#define AD760X_CHANNEL(num, mask_sep, mask_type, mask_all) {	\
 		.type = IIO_VOLTAGE,				\
 		.indexed = 1,					\
 		.channel = num,					\
 		.address = num,					\
-		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
-		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),\
-		.info_mask_shared_by_all = mask,		\
+		.info_mask_separate = mask_sep,			\
+		.info_mask_shared_by_type = mask_type,		\
+		.info_mask_shared_by_all = mask_all,		\
 		.scan_index = num,				\
 		.scan_type = {					\
 			.sign = 's',				\
@@ -25,11 +25,18 @@
 		},						\
 }
 
-#define AD7605_CHANNEL(num)	\
-	AD760X_CHANNEL(num, 0)
+#define AD7605_CHANNEL(num)				\
+	AD760X_CHANNEL(num, BIT(IIO_CHAN_INFO_RAW),	\
+		BIT(IIO_CHAN_INFO_SCALE), 0)
 
-#define AD7606_CHANNEL(num)	\
-	AD760X_CHANNEL(num, BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO))
+#define AD7606_CHANNEL(num)				\
+	AD760X_CHANNEL(num, BIT(IIO_CHAN_INFO_RAW),	\
+		BIT(IIO_CHAN_INFO_SCALE),		\
+		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO))
+
+#define AD7616_CHANNEL(num)	\
+	AD760X_CHANNEL(num, BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),\
+		0, BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO))
 
 /**
  * struct ad7606_chip_info - chip specific information
@@ -77,6 +84,7 @@ struct ad7606_chip_info {
  * @complete		completion to indicate end of conversion
  * @trig		The IIO trigger associated with the device.
  * @data		buffer for reading data from the device
+ * @d16			be16 buffer for reading data from the device
  */
 struct ad7606_state {
 	struct device			*dev;
@@ -110,6 +118,7 @@ struct ad7606_state {
 	 * 16 * 16-bit samples + 64-bit timestamp
 	 */
 	unsigned short			data[20] ____cacheline_aligned;
+	__be16				d16[2];
 };
 
 /**
@@ -117,11 +126,24 @@ struct ad7606_state {
  * @read_block		function pointer for reading blocks of data
  * @sw_mode_config:	pointer to a function which configured the device
  *			for software mode
+ * @reg_read	function pointer for reading spi register
+ * @reg_write	function pointer for writing spi register
+ * @write_mask	function pointer for write spi register with mask
+ * @rd_wr_cmd	pointer to the function which calculates the spi address
  */
 struct ad7606_bus_ops {
 	/* more methods added in future? */
 	int (*read_block)(struct device *dev, int num, void *data);
 	int (*sw_mode_config)(struct iio_dev *indio_dev);
+	int (*reg_read)(struct ad7606_state *st, unsigned int addr);
+	int (*reg_write)(struct ad7606_state *st,
+				unsigned int addr,
+				unsigned int val);
+	int (*write_mask)(struct ad7606_state *st,
+				 unsigned int addr,
+				 unsigned long mask,
+				 unsigned int val);
+	u16 (*rd_wr_cmd)(int addr, char isWriteOp);
 };
 
 int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,