staging: iio: adc: Enable driver support for ad799x AD converters (985dbe77) · Commits · e / devices / android_kernel_oneplus_sm7250

drivers/staging/iio/adc/Kconfig

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Original line number	Diff line number	Diff line
		@@ -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

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Original line number	Diff line number	Diff line
		@@ -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
		No newline at end of file

drivers/staging/iio/adc/ad799x.h

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Original line number	Diff line number	Diff line
		/*
		* 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_ */

drivers/staging/iio/adc/ad799x_core.c

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File added.

Preview size limit exceeded, changes collapsed.

drivers/staging/iio/adc/ad799x_ring.c

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Original line number	Diff line number	Diff line
		/*
		* 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_ring.c
		*/

		#include <linux/interrupt.h>
		#include <linux/workqueue.h>
		#include <linux/device.h>
		#include <linux/slab.h>
		#include <linux/kernel.h>
		#include <linux/sysfs.h>
		#include <linux/list.h>
		#include <linux/i2c.h>
		#include <linux/bitops.h>

		#include "../iio.h"
		#include "../ring_generic.h"
		#include "../ring_sw.h"
		#include "../trigger.h"
		#include "../sysfs.h"

		#include "ad799x.h"

		int ad799x_single_channel_from_ring(struct ad799x_state *st, long mask)
		{
		unsigned long numvals;
		int count = 0, ret;
		u16 *ring_data;
		if (!(st->indio_dev->ring->scan_mask & mask)) {
		ret = -EBUSY;
		goto error_ret;
		}
		numvals = st->indio_dev->ring->scan_count;

		ring_data = kmalloc(numvals*2, GFP_KERNEL);
		if (ring_data == NULL) {
		ret = -ENOMEM;
		goto error_ret;
		}
		ret = st->indio_dev->ring->access.read_last(st->indio_dev->ring,
		(u8 *) ring_data);
		if (ret)
		goto error_free_ring_data;
		/* Need a count of channels prior to this one */
		mask >>= 1;
		while (mask) {
		if (mask & st->indio_dev->ring->scan_mask)
		count++;
		mask >>= 1;
		}

		ret = be16_to_cpu(ring_data[count]) & 0xFFF;

		error_free_ring_data:
		kfree(ring_data);
		error_ret:
		return ret;
		}

		/**
		* ad799x_ring_preenable() setup the parameters of the ring before enabling
		*
		* The complex nature of the setting of the nuber of bytes per datum is due
		* to this driver currently ensuring that the timestamp is stored at an 8
		* byte boundary.
		**/
		static int ad799x_ring_preenable(struct iio_dev *indio_dev)
		{
		struct ad799x_state *st = indio_dev->dev_data;
		size_t d_size;
		unsigned long numvals;

		/*
		* Need to figure out the current mode based upon the requested
		* scan mask in iio_dev
		*/

		if (st->id == ad7997 \|\| st->id == ad7998)
		ad799x_set_scan_mode(st, st->indio_dev->ring->scan_mask);

		numvals = st->indio_dev->ring->scan_count;

		if (indio_dev->ring->access.set_bytes_per_datum) {
		d_size = numvals*2 + sizeof(s64);
		if (d_size % 8)
		d_size += 8 - (d_size % 8);
		indio_dev->ring->access.set_bytes_per_datum(indio_dev->ring,
		d_size);
		}

		return 0;
		}

		/**
		* ad799x_poll_func_th() th of trigger launched polling to ring buffer
		*
		* As sampling only occurs on i2c comms occuring, leave timestamping until
		* then. Some triggers will generate their own time stamp. Currently
		* there is no way of notifying them when no one cares.
		**/
		static void ad799x_poll_func_th(struct iio_dev *indio_dev, s64 time)
		{
		struct ad799x_state *st = indio_dev->dev_data;

		schedule_work(&st->poll_work);

		return;
		}
		/**
		* ad799x_poll_bh_to_ring() bh of trigger launched polling to ring buffer
		* @work_s: the work struct through which this was scheduled
		*
		* Currently there is no option in this driver to disable the saving of
		* timestamps within the ring.
		* I think the one copy of this at a time was to avoid problems if the
		* trigger was set far too high and the reads then locked up the computer.
		**/
		static void ad799x_poll_bh_to_ring(struct work_struct *work_s)
		{
		struct ad799x_state *st = container_of(work_s, struct ad799x_state,
		poll_work);
		struct iio_dev *indio_dev = st->indio_dev;
		struct iio_sw_ring_buffer *ring = iio_to_sw_ring(indio_dev->ring);
		s64 time_ns;
		__u8 *rxbuf;
		int b_sent;
		size_t d_size;
		u8 cmd;

		unsigned long numvals = st->indio_dev->ring->scan_count;

		/* Ensure the timestamp is 8 byte aligned */
		d_size = numvals*2 + sizeof(s64);

		if (d_size % sizeof(s64))
		d_size += sizeof(s64) - (d_size % sizeof(s64));

		/* Ensure only one copy of this function running at a time */
		if (atomic_inc_return(&st->protect_ring) > 1)
		return;

		/* Monitor mode prevents reading. Whilst not currently implemented
		* might as well have this test in here in the meantime as it does
		* no harm.
		*/
		if (numvals == 0)
		return;

		rxbuf = kmalloc(d_size, GFP_KERNEL);
		if (rxbuf == NULL)
		return;

		switch (st->id) {
		case ad7991:
		case ad7995:
		case ad7999:
		cmd = st->config \| (st->indio_dev->ring->scan_mask <<
		AD799X_CHANNEL_SHIFT);
		break;
		case ad7992:
		case ad7993:
		case ad7994:
		cmd = (st->indio_dev->ring->scan_mask <<
		AD799X_CHANNEL_SHIFT) \| AD7998_CONV_RES_REG;
		break;
		case ad7997:
		case ad7998:
		cmd = AD7997_8_READ_SEQUENCE \| AD7998_CONV_RES_REG;
		break;
		default:
		cmd = 0;
		}

		b_sent = i2c_smbus_read_i2c_block_data(st->client,
		cmd, numvals*2, rxbuf);
		if (b_sent < 0)
		goto done;

		time_ns = iio_get_time_ns();

		memcpy(rxbuf + d_size - sizeof(s64), &time_ns, sizeof(time_ns));

		indio_dev->ring->access.store_to(&ring->buf, rxbuf, time_ns);
		done:
		kfree(rxbuf);
		atomic_dec(&st->protect_ring);
		}


		int ad799x_register_ring_funcs_and_init(struct iio_dev *indio_dev)
		{
		struct ad799x_state *st = indio_dev->dev_data;
		int ret = 0;

		indio_dev->ring = iio_sw_rb_allocate(indio_dev);
		if (!indio_dev->ring) {
		ret = -ENOMEM;
		goto error_ret;
		}
		/* Effectively select the ring buffer implementation */
		iio_ring_sw_register_funcs(&st->indio_dev->ring->access);
		indio_dev->pollfunc = kzalloc(sizeof(*indio_dev->pollfunc), GFP_KERNEL);
		if (indio_dev->pollfunc == NULL) {
		ret = -ENOMEM;
		goto error_deallocate_sw_rb;
		}
		/* Configure the polling function called on trigger interrupts */
		indio_dev->pollfunc->poll_func_main = &ad799x_poll_func_th;
		indio_dev->pollfunc->private_data = indio_dev;

		/* Ring buffer functions - here trigger setup related */

		indio_dev->ring->preenable = &ad799x_ring_preenable;
		indio_dev->ring->postenable = &iio_triggered_ring_postenable;
		indio_dev->ring->predisable = &iio_triggered_ring_predisable;

		INIT_WORK(&st->poll_work, &ad799x_poll_bh_to_ring);

		indio_dev->ring->scan_el_attrs = st->chip_info->scan_attrs;

		/* Flag that polled ring buffering is possible */
		indio_dev->modes \|= INDIO_RING_TRIGGERED;
		return 0;
		error_deallocate_sw_rb:
		iio_sw_rb_free(indio_dev->ring);
		error_ret:
		return ret;
		}

		void ad799x_ring_cleanup(struct iio_dev *indio_dev)
		{
		/* ensure that the trigger has been detached */
		if (indio_dev->trig) {
		iio_put_trigger(indio_dev->trig);
		iio_trigger_dettach_poll_func(indio_dev->trig,
		indio_dev->pollfunc);
		}
		kfree(indio_dev->pollfunc);
		iio_sw_rb_free(indio_dev->ring);
		}