staging: iio: adc: Enable driver support for ad799x AD converters

Driver for ad7991, ad7995, ad7999, ad7992, ad7993, ad7994, ad7997 and
ad7998 multichannel ADC.

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/adc/Kconfig

@@ -26,3 +26,23 @@ config MAX1363_RING_BUFFER
 	help
 	  Say yes here to include ring buffer support in the MAX1363
 	  ADC driver.
+
+config AD799X
+	tristate "Analog Devices AD799x ADC driver"
+	depends on I2C
+	select IIO_TRIGGER if IIO_RING_BUFFER
+	select AD799X_RING_BUFFER
+	help
+	  Say yes here to build support for Analog Devices:
+	  ad7991, ad7995, ad7999, ad7992, ad7993, ad7994, ad7997, ad7998
+	  i2c analog to digital convertors (ADC). Provides direct access
+	  via sysfs.
+
+config AD799X_RING_BUFFER
+	bool "Analog Devices AD799x: use ring buffer"
+	depends on AD799X
+	select IIO_RING_BUFFER
+	select IIO_SW_RING
+	help
+	  Say yes here to include ring buffer support in the AD799X
+	  ADC driver.

drivers/staging/iio/adc/Makefile

@@ -6,3 +6,7 @@ max1363-y := max1363_core.o
 max1363-y += max1363_ring.o
 
 obj-$(CONFIG_MAX1363) += max1363.o
+
+ad799x-y := ad799x_core.o
+ad799x-$(CONFIG_AD799X_RING_BUFFER) += ad799x_ring.o
+obj-$(CONFIG_AD799X) += ad799x.o

drivers/staging/iio/adc/ad799x.h

@@ -0,0 +1,157 @@
+/*
+ * Copyright (C) 2010 Michael Hennerich, Analog Devices Inc.
+ * Copyright (C) 2008-2010 Jonathan Cameron
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * ad799x.h
+ */
+
+#ifndef _AD799X_H_
+#define  _AD799X_H_
+
+#define AD799X_CHANNEL_SHIFT			4
+
+/*
+ * AD7991, AD7995 and AD7999 defines
+ */
+
+#define AD7991_REF_SEL				0x08
+#define AD7991_FLTR				0x04
+#define AD7991_BIT_TRIAL_DELAY			0x02
+#define AD7991_SAMPLE_DELAY			0x01
+
+/*
+ * AD7992, AD7993, AD7994, AD7997 and AD7998 defines
+ */
+
+#define AD7998_FLTR				0x08
+#define AD7998_ALERT_EN				0x04
+#define AD7998_BUSY_ALERT			0x02
+#define AD7998_BUSY_ALERT_POL			0x01
+
+#define AD7998_CONV_RES_REG			0x0
+#define AD7998_ALERT_STAT_REG			0x1
+#define AD7998_CONF_REG				0x2
+#define AD7998_CYCLE_TMR_REG			0x3
+#define AD7998_DATALOW_CH1_REG			0x4
+#define AD7998_DATAHIGH_CH1_REG			0x5
+#define AD7998_HYST_CH1_REG			0x6
+#define AD7998_DATALOW_CH2_REG			0x7
+#define AD7998_DATAHIGH_CH2_REG			0x8
+#define AD7998_HYST_CH2_REG			0x9
+#define AD7998_DATALOW_CH3_REG			0xA
+#define AD7998_DATAHIGH_CH3_REG			0xB
+#define AD7998_HYST_CH3_REG			0xC
+#define AD7998_DATALOW_CH4_REG			0xD
+#define AD7998_DATAHIGH_CH4_REG			0xE
+#define AD7998_HYST_CH4_REG			0xF
+
+#define AD7998_CYC_MASK				0x7
+#define AD7998_CYC_DIS				0x0
+#define AD7998_CYC_TCONF_32			0x1
+#define AD7998_CYC_TCONF_64			0x2
+#define AD7998_CYC_TCONF_128			0x3
+#define AD7998_CYC_TCONF_256			0x4
+#define AD7998_CYC_TCONF_512			0x5
+#define AD7998_CYC_TCONF_1024			0x6
+#define AD7998_CYC_TCONF_2048			0x7
+
+#define AD7998_ALERT_STAT_CLEAR			0xFF
+
+/*
+ * AD7997 and AD7997 defines
+ */
+
+#define AD7997_8_READ_SINGLE			0x80
+#define AD7997_8_READ_SEQUENCE			0x70
+
+enum {
+	ad7991,
+	ad7995,
+	ad7999,
+	ad7992,
+	ad7993,
+	ad7994,
+	ad7997,
+	ad7998
+};
+
+struct ad799x_state;
+
+/**
+ * struct ad799x_chip_info - chip specifc information
+ * @num_inputs:		number of physical inputs on chip
+ * @bits:		accuracy of the adc in bits
+ * @int_vref_mv:	the internal reference voltage
+ * @monitor_mode:	whether the chip supports monitor interrupts
+ * @default_config:	device default configuration
+ * @dev_attrs:		pointer to the device attribute group
+ * @scan_attrs:		pointer to the scan element attribute group
+ * @event_attrs:	pointer to the monitor event attribute group
+ * @ad799x_set_scan_mode: function pointer to the device specific mode function
+
+ */
+struct ad799x_chip_info {
+	u8				num_inputs;
+	u8				bits;
+	u16				int_vref_mv;
+	bool				monitor_mode;
+	u16				default_config;
+	struct attribute_group		*dev_attrs;
+	struct attribute_group		*scan_attrs;
+	struct attribute_group		*event_attrs;
+	int (*ad799x_set_scan_mode)	(struct ad799x_state *st,
+					unsigned mask);
+};
+
+struct ad799x_state {
+	struct iio_dev			*indio_dev;
+	struct i2c_client		*client;
+	const struct ad799x_chip_info	*chip_info;
+	struct work_struct		poll_work;
+	struct work_struct		work_thresh;
+	atomic_t			protect_ring;
+	struct iio_trigger		*trig;
+	struct regulator		*reg;
+	s64				last_timestamp;
+	u16				int_vref_mv;
+	unsigned			id;
+	char				*name;
+	u16				config;
+};
+
+/*
+ * TODO: struct ad799x_platform_data needs to go into inlude/linux/iio
+ */
+
+struct ad799x_platform_data {
+	u16				vref_mv;
+};
+
+int ad799x_set_scan_mode(struct ad799x_state *st, unsigned mask);
+
+#ifdef CONFIG_AD799X_RING_BUFFER
+int ad799x_single_channel_from_ring(struct ad799x_state *st, long mask);
+int ad799x_register_ring_funcs_and_init(struct iio_dev *indio_dev);
+void ad799x_ring_cleanup(struct iio_dev *indio_dev);
+#else /* CONFIG_AD799X_RING_BUFFER */
+int ad799x_single_channel_from_ring(struct ad799x_state *st, long mask)
+{
+	return -EINVAL;
+}
+
+
+static inline int
+ad799x_register_ring_funcs_and_init(struct iio_dev *indio_dev)
+{
+	return 0;
+}
+
+static inline void ad799x_ring_cleanup(struct iio_dev *indio_dev)
+{
+}
+#endif /* CONFIG_AD799X_RING_BUFFER */
+#endif /* _AD799X_H_ */