Staging: IIO: DDS: AD9832 / AD9835 driver

This is a complete rewrite of the AD9832/35 driver.
Purpose was to move this driver to the recently
created API for such devices.

Changes since V1:
IIO: DDS: AD9832 / AD9835 driver: Apply review feedback

Save a few bytes, use union for data allocated for spi buffers.
Remove use of device IDs.
Fix comments.
Make master clock mclk always type unsigned long.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/dds/Kconfig

@@ -15,7 +15,10 @@ config AD9832
 	depends on SPI
 	help
 	  Say yes here to build support for Analog Devices DDS chip
-	  ad9832 and ad9835, provides direct access via sysfs.
+	  AD9832 and AD9835, provides direct access via sysfs.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad9832.
 
 config AD9834
 	tristate "Analog Devices ad9833/4/ driver"

drivers/staging/iio/dds/ad9832.h

+/*
+ * AD9832 SPI DDS driver
+ *
+ * Copyright 2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+#ifndef IIO_DDS_AD9832_H_
+#define IIO_DDS_AD9832_H_
+
+/* Registers */
+
+#define AD9832_FREQ0LL		0x0
+#define AD9832_FREQ0HL		0x1
+#define AD9832_FREQ0LM		0x2
+#define AD9832_FREQ0HM		0x3
+#define AD9832_FREQ1LL		0x4
+#define AD9832_FREQ1HL		0x5
+#define AD9832_FREQ1LM		0x6
+#define AD9832_FREQ1HM		0x7
+#define AD9832_PHASE0L		0x8
+#define AD9832_PHASE0H		0x9
+#define AD9832_PHASE1L		0xA
+#define AD9832_PHASE1H		0xB
+#define AD9832_PHASE2L		0xC
+#define AD9832_PHASE2H		0xD
+#define AD9832_PHASE3L		0xE
+#define AD9832_PHASE3H		0xF
+
+#define AD9832_PHASE_SYM	0x10
+#define AD9832_FREQ_SYM		0x11
+#define AD9832_PINCTRL_EN	0x12
+#define AD9832_OUTPUT_EN	0x13
+
+/* Command Control Bits */
+
+#define AD9832_CMD_PHA8BITSW	0x1
+#define AD9832_CMD_PHA16BITSW	0x0
+#define AD9832_CMD_FRE8BITSW	0x3
+#define AD9832_CMD_FRE16BITSW	0x2
+#define AD9832_CMD_FPSELECT	0x6
+#define AD9832_CMD_SYNCSELSRC	0x8
+#define AD9832_CMD_SLEEPRESCLR	0xC
+
+#define AD9832_FREQ		(1 << 11)
+#define AD9832_PHASE(x)		(((x) & 3) << 9)
+#define AD9832_SYNC		(1 << 13)
+#define AD9832_SELSRC		(1 << 12)
+#define AD9832_SLEEP		(1 << 13)
+#define AD9832_RESET		(1 << 12)
+#define AD9832_CLR		(1 << 11)
+#define CMD_SHIFT		12
+#define ADD_SHIFT		8
+#define AD9832_FREQ_BITS	32
+#define AD9832_PHASE_BITS	12
+#define RES_MASK(bits)		((1 << (bits)) - 1)
+
+/**
+ * struct ad9832_state - driver instance specific data
+ * @indio_dev:		the industrial I/O device
+ * @spi:		spi_device
+ * @reg:		supply regulator
+ * @mclk:		external master clock
+ * @ctrl_fp:		cached frequency/phase control word
+ * @ctrl_ss:		cached sync/selsrc control word
+ * @ctrl_src:		cached sleep/reset/clr word
+ * @xfer:		default spi transfer
+ * @msg:		default spi message
+ * @freq_xfer:		tuning word spi transfer
+ * @freq_msg:		tuning word spi message
+ * @phase_xfer:		tuning word spi transfer
+ * @phase_msg:		tuning word spi message
+ * @data:		spi transmit buffer
+ * @phase_data:		tuning word spi transmit buffer
+ * @freq_data:		tuning word spi transmit buffer
+ */
+
+struct ad9832_state {
+	struct iio_dev			*indio_dev;
+	struct spi_device		*spi;
+	struct regulator		*reg;
+	unsigned long			mclk;
+	unsigned short			ctrl_fp;
+	unsigned short			ctrl_ss;
+	unsigned short			ctrl_src;
+	struct spi_transfer		xfer;
+	struct spi_message		msg;
+	struct spi_transfer		freq_xfer[4];
+	struct spi_message		freq_msg;
+	struct spi_transfer		phase_xfer[2];
+	struct spi_message		phase_msg;
+	/*
+	 * DMA (thus cache coherency maintenance) requires the
+	 * transfer buffers to live in their own cache lines.
+	 */
+	union {
+		unsigned short		freq_data[4]____cacheline_aligned;
+		unsigned short		phase_data[2];
+		unsigned short		data;
+	};
+};
+
+/*
+ * TODO: struct ad9832_platform_data needs to go into include/linux/iio
+ */
+
+/**
+ * struct ad9832_platform_data - platform specific information
+ * @mclk:		master clock in Hz
+ * @freq0:		power up freq0 tuning word in Hz
+ * @freq1:		power up freq1 tuning word in Hz
+ * @phase0:		power up phase0 value [0..4095] correlates with 0..2PI
+ * @phase1:		power up phase1 value [0..4095] correlates with 0..2PI
+ * @phase2:		power up phase2 value [0..4095] correlates with 0..2PI
+ * @phase3:		power up phase3 value [0..4095] correlates with 0..2PI
+ */
+
+struct ad9832_platform_data {
+	unsigned long		mclk;
+	unsigned long		freq0;
+	unsigned long		freq1;
+	unsigned short		phase0;
+	unsigned short		phase1;
+	unsigned short		phase2;
+	unsigned short		phase3;
+};
+
+#endif /* IIO_DDS_AD9832_H_ */