staging: iio: adc: Enable driver support for ad7887 AD converter
Enable support for AD7887: SPI Micropower, 2-Channel, 125 kSPS, 12-Bit ADC staging: iio: adc: Fix according to review feedback Review feedback by Jonathan Cameron: Combine statements. Document struct members. Remove redundant variable initialization. Simplify multichannel scan from ring logic. Fix coding style. [v2] staging: iio: adc: ad7887: Fix typos 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>
This commit is contained in:
Michael Hennerich
Greg Kroah-Hartman
parent
b5a4948175
commit
2b4756aa36
|
|
@ -97,6 +97,20 @@ config AD7476
|
|||
To compile this driver as a module, choose M here: the
|
||||
module will be called ad7476.
|
||||
|
||||
config AD7887
|
||||
tristate "Analog Devices AD7887 ADC driver"
|
||||
depends on SPI
|
||||
select IIO_RING_BUFFER
|
||||
select IIO_SW_RING
|
||||
select IIO_TRIGGER
|
||||
help
|
||||
Say yes here to build support for Analog Devices
|
||||
AD7887 SPI analog to digital convertor (ADC).
|
||||
If unsure, say N (but it's safe to say "Y").
|
||||
|
||||
To compile this driver as a module, choose M here: the
|
||||
module will be called ad7887.
|
||||
|
||||
config AD7745
|
||||
tristate "Analog Devices AD7745, AD7746 AD7747 capacitive sensor driver"
|
||||
depends on I2C
|
||||
|
|
|
|||
|
|
@ -15,6 +15,10 @@ ad7476-y := ad7476_core.o
|
|||
ad7476-$(CONFIG_IIO_RING_BUFFER) += ad7476_ring.o
|
||||
obj-$(CONFIG_AD7476) += ad7476.o
|
||||
|
||||
ad7887-y := ad7887_core.o
|
||||
ad7887-$(CONFIG_IIO_RING_BUFFER) += ad7887_ring.o
|
||||
obj-$(CONFIG_AD7887) += ad7887.o
|
||||
|
||||
obj-$(CONFIG_AD7150) += ad7150.o
|
||||
obj-$(CONFIG_AD7152) += ad7152.o
|
||||
obj-$(CONFIG_AD7291) += ad7291.o
|
||||
|
|
|
|||
|
|
@ -0,0 +1,105 @@
|
|||
/*
|
||||
* AD7887 SPI ADC driver
|
||||
*
|
||||
* Copyright 2010 Analog Devices Inc.
|
||||
*
|
||||
* Licensed under the GPL-2 or later.
|
||||
*/
|
||||
#ifndef IIO_ADC_AD7887_H_
|
||||
#define IIO_ADC_AD7887_H_
|
||||
|
||||
#define AD7887_REF_DIS (1 << 5) /* on-chip reference disable */
|
||||
#define AD7887_DUAL (1 << 4) /* dual-channel mode */
|
||||
#define AD7887_CH_AIN1 (1 << 3) /* convert on channel 1, DUAL=1 */
|
||||
#define AD7887_CH_AIN0 (0 << 3) /* convert on channel 0, DUAL=0,1 */
|
||||
#define AD7887_PM_MODE1 (0) /* CS based shutdown */
|
||||
#define AD7887_PM_MODE2 (1) /* full on */
|
||||
#define AD7887_PM_MODE3 (2) /* auto shutdown after conversion */
|
||||
#define AD7887_PM_MODE4 (3) /* standby mode */
|
||||
|
||||
enum ad7887_channels {
|
||||
AD7887_CH0,
|
||||
AD7887_CH0_CH1,
|
||||
AD7887_CH1,
|
||||
};
|
||||
|
||||
#define RES_MASK(bits) ((1 << (bits)) - 1) /* TODO: move this into a common header */
|
||||
|
||||
/*
|
||||
* TODO: struct ad7887_platform_data needs to go into include/linux/iio
|
||||
*/
|
||||
|
||||
struct ad7887_platform_data {
|
||||
/* External Vref voltage applied */
|
||||
u16 vref_mv;
|
||||
/*
|
||||
* AD7887:
|
||||
* In single channel mode en_dual = flase, AIN1/Vref pins assumes its
|
||||
* Vref function. In dual channel mode en_dual = true, AIN1 becomes the
|
||||
* second input channel, and Vref is internally connected to Vdd.
|
||||
*/
|
||||
bool en_dual;
|
||||
/*
|
||||
* AD7887:
|
||||
* use_onchip_ref = true, the Vref is internally connected to the 2.500V
|
||||
* Voltage reference. If use_onchip_ref = false, the reference voltage
|
||||
* is supplied by AIN1/Vref
|
||||
*/
|
||||
bool use_onchip_ref;
|
||||
};
|
||||
|
||||
struct ad7887_chip_info {
|
||||
u8 bits; /* number of ADC bits */
|
||||
u8 storagebits; /* number of bits read from the ADC */
|
||||
u8 left_shift; /* number of bits the sample must be shifted */
|
||||
char sign; /* [s]igned or [u]nsigned */
|
||||
u16 int_vref_mv; /* internal reference voltage */
|
||||
};
|
||||
|
||||
struct ad7887_state {
|
||||
struct iio_dev *indio_dev;
|
||||
struct spi_device *spi;
|
||||
const struct ad7887_chip_info *chip_info;
|
||||
struct regulator *reg;
|
||||
struct work_struct poll_work;
|
||||
atomic_t protect_ring;
|
||||
u16 int_vref_mv;
|
||||
bool en_dual;
|
||||
struct spi_transfer xfer[4];
|
||||
struct spi_message msg[3];
|
||||
struct spi_message *ring_msg;
|
||||
unsigned char tx_cmd_buf[8];
|
||||
|
||||
/*
|
||||
* DMA (thus cache coherency maintenance) requires the
|
||||
* transfer buffers to live in their own cache lines.
|
||||
*/
|
||||
|
||||
unsigned char data[4] ____cacheline_aligned;
|
||||
};
|
||||
|
||||
enum ad7887_supported_device_ids {
|
||||
ID_AD7887
|
||||
};
|
||||
|
||||
#ifdef CONFIG_IIO_RING_BUFFER
|
||||
int ad7887_scan_from_ring(struct ad7887_state *st, long mask);
|
||||
int ad7887_register_ring_funcs_and_init(struct iio_dev *indio_dev);
|
||||
void ad7887_ring_cleanup(struct iio_dev *indio_dev);
|
||||
#else /* CONFIG_IIO_RING_BUFFER */
|
||||
static inline int ad7887_scan_from_ring(struct ad7887_state *st, long mask)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline int
|
||||
ad7887_register_ring_funcs_and_init(struct iio_dev *indio_dev)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline void ad7887_ring_cleanup(struct iio_dev *indio_dev)
|
||||
{
|
||||
}
|
||||
#endif /* CONFIG_IIO_RING_BUFFER */
|
||||
#endif /* IIO_ADC_AD7887_H_ */
|
||||
|
|
@ -0,0 +1,305 @@
|
|||
/*
|
||||
* AD7887 SPI ADC driver
|
||||
*
|
||||
* Copyright 2010 Analog Devices Inc.
|
||||
*
|
||||
* Licensed under the GPL-2 or later.
|
||||
*/
|
||||
|
||||
#include <linux/interrupt.h>
|
||||
#include <linux/workqueue.h>
|
||||
#include <linux/device.h>
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/slab.h>
|
||||
#include <linux/sysfs.h>
|
||||
#include <linux/list.h>
|
||||
#include <linux/spi/spi.h>
|
||||
#include <linux/regulator/consumer.h>
|
||||
#include <linux/err.h>
|
||||
|
||||
#include "../iio.h"
|
||||
#include "../sysfs.h"
|
||||
#include "../ring_generic.h"
|
||||
#include "adc.h"
|
||||
|
||||
#include "ad7887.h"
|
||||
|
||||
static int ad7887_scan_direct(struct ad7887_state *st, unsigned ch)
|
||||
{
|
||||
int ret = spi_sync(st->spi, &st->msg[ch]);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
return (st->data[(ch * 2)] << 8) | st->data[(ch * 2) + 1];
|
||||
}
|
||||
|
||||
static ssize_t ad7887_scan(struct device *dev,
|
||||
struct device_attribute *attr,
|
||||
char *buf)
|
||||
{
|
||||
struct iio_dev *dev_info = dev_get_drvdata(dev);
|
||||
struct ad7887_state *st = dev_info->dev_data;
|
||||
struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
|
||||
int ret;
|
||||
|
||||
mutex_lock(&dev_info->mlock);
|
||||
if (iio_ring_enabled(dev_info))
|
||||
ret = ad7887_scan_from_ring(st, 1 << this_attr->address);
|
||||
else
|
||||
ret = ad7887_scan_direct(st, this_attr->address);
|
||||
mutex_unlock(&dev_info->mlock);
|
||||
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
return sprintf(buf, "%d\n", (ret >> st->chip_info->left_shift) &
|
||||
RES_MASK(st->chip_info->bits));
|
||||
}
|
||||
static IIO_DEV_ATTR_IN_RAW(0, ad7887_scan, 0);
|
||||
static IIO_DEV_ATTR_IN_RAW(1, ad7887_scan, 1);
|
||||
|
||||
static ssize_t ad7887_show_scale(struct device *dev,
|
||||
struct device_attribute *attr,
|
||||
char *buf)
|
||||
{
|
||||
/* Driver currently only support internal vref */
|
||||
struct iio_dev *dev_info = dev_get_drvdata(dev);
|
||||
struct ad7887_state *st = iio_dev_get_devdata(dev_info);
|
||||
/* Corresponds to Vref / 2^(bits) */
|
||||
unsigned int scale_uv = (st->int_vref_mv * 1000) >> st->chip_info->bits;
|
||||
|
||||
return sprintf(buf, "%d.%d\n", scale_uv / 1000, scale_uv % 1000);
|
||||
}
|
||||
static IIO_DEVICE_ATTR(in_scale, S_IRUGO, ad7887_show_scale, NULL, 0);
|
||||
|
||||
static ssize_t ad7887_show_name(struct device *dev,
|
||||
struct device_attribute *attr,
|
||||
char *buf)
|
||||
{
|
||||
struct iio_dev *dev_info = dev_get_drvdata(dev);
|
||||
struct ad7887_state *st = iio_dev_get_devdata(dev_info);
|
||||
|
||||
return sprintf(buf, "%s\n", spi_get_device_id(st->spi)->name);
|
||||
}
|
||||
static IIO_DEVICE_ATTR(name, S_IRUGO, ad7887_show_name, NULL, 0);
|
||||
|
||||
static struct attribute *ad7887_attributes[] = {
|
||||
&iio_dev_attr_in0_raw.dev_attr.attr,
|
||||
&iio_dev_attr_in1_raw.dev_attr.attr,
|
||||
&iio_dev_attr_in_scale.dev_attr.attr,
|
||||
&iio_dev_attr_name.dev_attr.attr,
|
||||
NULL,
|
||||
};
|
||||
|
||||
static mode_t ad7887_attr_is_visible(struct kobject *kobj,
|
||||
struct attribute *attr, int n)
|
||||
{
|
||||
struct device *dev = container_of(kobj, struct device, kobj);
|
||||
struct iio_dev *dev_info = dev_get_drvdata(dev);
|
||||
struct ad7887_state *st = iio_dev_get_devdata(dev_info);
|
||||
|
||||
mode_t mode = attr->mode;
|
||||
|
||||
if ((attr == &iio_dev_attr_in1_raw.dev_attr.attr) && !st->en_dual)
|
||||
mode = 0;
|
||||
|
||||
return mode;
|
||||
}
|
||||
|
||||
static const struct attribute_group ad7887_attribute_group = {
|
||||
.attrs = ad7887_attributes,
|
||||
.is_visible = ad7887_attr_is_visible,
|
||||
};
|
||||
|
||||
static const struct ad7887_chip_info ad7887_chip_info_tbl[] = {
|
||||
/*
|
||||
* More devices added in future
|
||||
*/
|
||||
[ID_AD7887] = {
|
||||
.bits = 12,
|
||||
.storagebits = 16,
|
||||
.left_shift = 0,
|
||||
.sign = IIO_SCAN_EL_TYPE_UNSIGNED,
|
||||
.int_vref_mv = 2500,
|
||||
},
|
||||
};
|
||||
|
||||
static int __devinit ad7887_probe(struct spi_device *spi)
|
||||
{
|
||||
struct ad7887_platform_data *pdata = spi->dev.platform_data;
|
||||
struct ad7887_state *st;
|
||||
int ret, voltage_uv = 0;
|
||||
|
||||
st = kzalloc(sizeof(*st), GFP_KERNEL);
|
||||
if (st == NULL) {
|
||||
ret = -ENOMEM;
|
||||
goto error_ret;
|
||||
}
|
||||
|
||||
st->reg = regulator_get(&spi->dev, "vcc");
|
||||
if (!IS_ERR(st->reg)) {
|
||||
ret = regulator_enable(st->reg);
|
||||
if (ret)
|
||||
goto error_put_reg;
|
||||
|
||||
voltage_uv = regulator_get_voltage(st->reg);
|
||||
}
|
||||
|
||||
st->chip_info =
|
||||
&ad7887_chip_info_tbl[spi_get_device_id(spi)->driver_data];
|
||||
|
||||
spi_set_drvdata(spi, st);
|
||||
|
||||
atomic_set(&st->protect_ring, 0);
|
||||
st->spi = spi;
|
||||
|
||||
st->indio_dev = iio_allocate_device();
|
||||
if (st->indio_dev == NULL) {
|
||||
ret = -ENOMEM;
|
||||
goto error_disable_reg;
|
||||
}
|
||||
|
||||
/* Estabilish that the iio_dev is a child of the spi device */
|
||||
st->indio_dev->dev.parent = &spi->dev;
|
||||
st->indio_dev->attrs = &ad7887_attribute_group;
|
||||
st->indio_dev->dev_data = (void *)(st);
|
||||
st->indio_dev->driver_module = THIS_MODULE;
|
||||
st->indio_dev->modes = INDIO_DIRECT_MODE;
|
||||
|
||||
/* Setup default message */
|
||||
|
||||
st->tx_cmd_buf[0] = AD7887_CH_AIN0 | AD7887_PM_MODE4 |
|
||||
((pdata && pdata->use_onchip_ref) ?
|
||||
0 : AD7887_REF_DIS);
|
||||
|
||||
st->xfer[0].rx_buf = &st->data[0];
|
||||
st->xfer[0].tx_buf = &st->tx_cmd_buf[0];
|
||||
st->xfer[0].len = 2;
|
||||
|
||||
spi_message_init(&st->msg[AD7887_CH0]);
|
||||
spi_message_add_tail(&st->xfer[0], &st->msg[AD7887_CH0]);
|
||||
|
||||
if (pdata && pdata->en_dual) {
|
||||
st->tx_cmd_buf[0] |= AD7887_DUAL | AD7887_REF_DIS;
|
||||
|
||||
st->tx_cmd_buf[2] = AD7887_CH_AIN1 | AD7887_DUAL |
|
||||
AD7887_REF_DIS | AD7887_PM_MODE4;
|
||||
st->tx_cmd_buf[4] = AD7887_CH_AIN0 | AD7887_DUAL |
|
||||
AD7887_REF_DIS | AD7887_PM_MODE4;
|
||||
st->tx_cmd_buf[6] = AD7887_CH_AIN1 | AD7887_DUAL |
|
||||
AD7887_REF_DIS | AD7887_PM_MODE4;
|
||||
|
||||
st->xfer[1].rx_buf = &st->data[0];
|
||||
st->xfer[1].tx_buf = &st->tx_cmd_buf[2];
|
||||
st->xfer[1].len = 2;
|
||||
|
||||
st->xfer[2].rx_buf = &st->data[2];
|
||||
st->xfer[2].tx_buf = &st->tx_cmd_buf[4];
|
||||
st->xfer[2].len = 2;
|
||||
|
||||
spi_message_init(&st->msg[AD7887_CH0_CH1]);
|
||||
spi_message_add_tail(&st->xfer[1], &st->msg[AD7887_CH0_CH1]);
|
||||
spi_message_add_tail(&st->xfer[2], &st->msg[AD7887_CH0_CH1]);
|
||||
|
||||
st->xfer[3].rx_buf = &st->data[0];
|
||||
st->xfer[3].tx_buf = &st->tx_cmd_buf[6];
|
||||
st->xfer[3].len = 2;
|
||||
|
||||
spi_message_init(&st->msg[AD7887_CH1]);
|
||||
spi_message_add_tail(&st->xfer[3], &st->msg[AD7887_CH1]);
|
||||
|
||||
st->en_dual = true;
|
||||
|
||||
if (pdata && pdata->vref_mv)
|
||||
st->int_vref_mv = pdata->vref_mv;
|
||||
else if (voltage_uv)
|
||||
st->int_vref_mv = voltage_uv / 1000;
|
||||
else
|
||||
dev_warn(&spi->dev, "reference voltage unspecified\n");
|
||||
|
||||
} else {
|
||||
if (pdata && pdata->vref_mv)
|
||||
st->int_vref_mv = pdata->vref_mv;
|
||||
else if (pdata && pdata->use_onchip_ref)
|
||||
st->int_vref_mv = st->chip_info->int_vref_mv;
|
||||
else
|
||||
dev_warn(&spi->dev, "reference voltage unspecified\n");
|
||||
}
|
||||
|
||||
|
||||
ret = ad7887_register_ring_funcs_and_init(st->indio_dev);
|
||||
if (ret)
|
||||
goto error_free_device;
|
||||
|
||||
ret = iio_device_register(st->indio_dev);
|
||||
if (ret)
|
||||
goto error_free_device;
|
||||
|
||||
ret = iio_ring_buffer_register(st->indio_dev->ring, 0);
|
||||
if (ret)
|
||||
goto error_cleanup_ring;
|
||||
return 0;
|
||||
|
||||
error_cleanup_ring:
|
||||
ad7887_ring_cleanup(st->indio_dev);
|
||||
iio_device_unregister(st->indio_dev);
|
||||
error_free_device:
|
||||
iio_free_device(st->indio_dev);
|
||||
error_disable_reg:
|
||||
if (!IS_ERR(st->reg))
|
||||
regulator_disable(st->reg);
|
||||
error_put_reg:
|
||||
if (!IS_ERR(st->reg))
|
||||
regulator_put(st->reg);
|
||||
kfree(st);
|
||||
error_ret:
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int ad7887_remove(struct spi_device *spi)
|
||||
{
|
||||
struct ad7887_state *st = spi_get_drvdata(spi);
|
||||
struct iio_dev *indio_dev = st->indio_dev;
|
||||
iio_ring_buffer_unregister(indio_dev->ring);
|
||||
ad7887_ring_cleanup(indio_dev);
|
||||
iio_device_unregister(indio_dev);
|
||||
if (!IS_ERR(st->reg)) {
|
||||
regulator_disable(st->reg);
|
||||
regulator_put(st->reg);
|
||||
}
|
||||
kfree(st);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static const struct spi_device_id ad7887_id[] = {
|
||||
{"ad7887", ID_AD7887},
|
||||
{}
|
||||
};
|
||||
|
||||
static struct spi_driver ad7887_driver = {
|
||||
.driver = {
|
||||
.name = "ad7887",
|
||||
.bus = &spi_bus_type,
|
||||
.owner = THIS_MODULE,
|
||||
},
|
||||
.probe = ad7887_probe,
|
||||
.remove = __devexit_p(ad7887_remove),
|
||||
.id_table = ad7887_id,
|
||||
};
|
||||
|
||||
static int __init ad7887_init(void)
|
||||
{
|
||||
return spi_register_driver(&ad7887_driver);
|
||||
}
|
||||
module_init(ad7887_init);
|
||||
|
||||
static void __exit ad7887_exit(void)
|
||||
{
|
||||
spi_unregister_driver(&ad7887_driver);
|
||||
}
|
||||
module_exit(ad7887_exit);
|
||||
|
||||
MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
|
||||
MODULE_DESCRIPTION("Analog Devices AD7887 ADC");
|
||||
MODULE_LICENSE("GPL v2");
|
||||
MODULE_ALIAS("spi:ad7887");
|
||||
|
|
@ -0,0 +1,266 @@
|
|||
/*
|
||||
* Copyright 2010 Analog Devices Inc.
|
||||
* Copyright (C) 2008 Jonathan Cameron
|
||||
*
|
||||
* Licensed under the GPL-2 or later.
|
||||
*
|
||||
* ad7887_ring.c
|
||||
*/
|
||||
|
||||
#include <linux/interrupt.h>
|
||||
#include <linux/gpio.h>
|
||||
#include <linux/workqueue.h>
|
||||
#include <linux/device.h>
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/slab.h>
|
||||
#include <linux/sysfs.h>
|
||||
#include <linux/list.h>
|
||||
#include <linux/spi/spi.h>
|
||||
|
||||
#include "../iio.h"
|
||||
#include "../ring_generic.h"
|
||||
#include "../ring_sw.h"
|
||||
#include "../trigger.h"
|
||||
#include "../sysfs.h"
|
||||
|
||||
#include "ad7887.h"
|
||||
|
||||
static IIO_SCAN_EL_C(in0, 0, 0, NULL);
|
||||
static IIO_SCAN_EL_C(in1, 1, 0, NULL);
|
||||
|
||||
static ssize_t ad7887_show_type(struct device *dev,
|
||||
struct device_attribute *attr,
|
||||
char *buf)
|
||||
{
|
||||
struct iio_ring_buffer *ring = dev_get_drvdata(dev);
|
||||
struct iio_dev *indio_dev = ring->indio_dev;
|
||||
struct ad7887_state *st = indio_dev->dev_data;
|
||||
|
||||
return sprintf(buf, "%c%d/%d>>%d\n", st->chip_info->sign,
|
||||
st->chip_info->bits, st->chip_info->storagebits,
|
||||
st->chip_info->left_shift);
|
||||
}
|
||||
static IIO_DEVICE_ATTR(in_type, S_IRUGO, ad7887_show_type, NULL, 0);
|
||||
|
||||
static struct attribute *ad7887_scan_el_attrs[] = {
|
||||
&iio_scan_el_in0.dev_attr.attr,
|
||||
&iio_const_attr_in0_index.dev_attr.attr,
|
||||
&iio_scan_el_in1.dev_attr.attr,
|
||||
&iio_const_attr_in1_index.dev_attr.attr,
|
||||
&iio_dev_attr_in_type.dev_attr.attr,
|
||||
NULL,
|
||||
};
|
||||
|
||||
static mode_t ad7887_scan_el_attr_is_visible(struct kobject *kobj,
|
||||
struct attribute *attr, int n)
|
||||
{
|
||||
struct device *dev = container_of(kobj, struct device, kobj);
|
||||
struct iio_ring_buffer *ring = dev_get_drvdata(dev);
|
||||
struct iio_dev *indio_dev = ring->indio_dev;
|
||||
struct ad7887_state *st = indio_dev->dev_data;
|
||||
|
||||
mode_t mode = attr->mode;
|
||||
|
||||
if ((attr == &iio_scan_el_in1.dev_attr.attr) ||
|
||||
(attr == &iio_const_attr_in1_index.dev_attr.attr))
|
||||
if (!st->en_dual)
|
||||
mode = 0;
|
||||
|
||||
return mode;
|
||||
}
|
||||
|
||||
static struct attribute_group ad7887_scan_el_group = {
|
||||
.name = "scan_elements",
|
||||
.attrs = ad7887_scan_el_attrs,
|
||||
.is_visible = ad7887_scan_el_attr_is_visible,
|
||||
};
|
||||
|
||||
int ad7887_scan_from_ring(struct ad7887_state *st, long mask)
|
||||
{
|
||||
struct iio_ring_buffer *ring = st->indio_dev->ring;
|
||||
int count = 0, ret;
|
||||
u16 *ring_data;
|
||||
|
||||
if (!(ring->scan_mask & mask)) {
|
||||
ret = -EBUSY;
|
||||
goto error_ret;
|
||||
}
|
||||
|
||||
ring_data = kmalloc(ring->access.get_bytes_per_datum(ring), GFP_KERNEL);
|
||||
if (ring_data == NULL) {
|
||||
ret = -ENOMEM;
|
||||
goto error_ret;
|
||||
}
|
||||
ret = ring->access.read_last(ring, (u8 *) ring_data);
|
||||
if (ret)
|
||||
goto error_free_ring_data;
|
||||
|
||||
/* for single channel scan the result is stored with zero offset */
|
||||
if ((ring->scan_mask == ((1 << 1) | (1 << 0))) && (mask == (1 << 1)))
|
||||
count = 1;
|
||||
|
||||
ret = be16_to_cpu(ring_data[count]);
|
||||
|
||||
error_free_ring_data:
|
||||
kfree(ring_data);
|
||||
error_ret:
|
||||
return ret;
|
||||
}
|
||||
|
||||
/**
|
||||
* ad7887_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 ad7887_ring_preenable(struct iio_dev *indio_dev)
|
||||
{
|
||||
struct ad7887_state *st = indio_dev->dev_data;
|
||||
struct iio_ring_buffer *ring = indio_dev->ring;
|
||||
size_t d_size;
|
||||
|
||||
if (indio_dev->ring->access.set_bytes_per_datum) {
|
||||
d_size = st->chip_info->storagebits / 8 + 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);
|
||||
}
|
||||
|
||||
switch (ring->scan_mask) {
|
||||
case (1 << 0):
|
||||
st->ring_msg = &st->msg[AD7887_CH0];
|
||||
break;
|
||||
case (1 << 1):
|
||||
st->ring_msg = &st->msg[AD7887_CH1];
|
||||
/* Dummy read: push CH1 setting down to hardware */
|
||||
spi_sync(st->spi, st->ring_msg);
|
||||
break;
|
||||
case ((1 << 1) | (1 << 0)):
|
||||
st->ring_msg = &st->msg[AD7887_CH0_CH1];
|
||||
break;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int ad7887_ring_postdisable(struct iio_dev *indio_dev)
|
||||
{
|
||||
struct ad7887_state *st = indio_dev->dev_data;
|
||||
|
||||
/* dummy read: restore default CH0 settin */
|
||||
return spi_sync(st->spi, &st->msg[AD7887_CH0]);
|
||||
}
|
||||
|
||||
/**
|
||||
* ad7887_poll_func_th() th of trigger launched polling to ring buffer
|
||||
*
|
||||
* As sampling only occurs on spi 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 ad7887_poll_func_th(struct iio_dev *indio_dev, s64 time)
|
||||
{
|
||||
struct ad7887_state *st = indio_dev->dev_data;
|
||||
|
||||
schedule_work(&st->poll_work);
|
||||
return;
|
||||
}
|
||||
/**
|
||||
* ad7887_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 ad7887_poll_bh_to_ring(struct work_struct *work_s)
|
||||
{
|
||||
struct ad7887_state *st = container_of(work_s, struct ad7887_state,
|
||||
poll_work);
|
||||
struct iio_dev *indio_dev = st->indio_dev;
|
||||
struct iio_sw_ring_buffer *sw_ring = iio_to_sw_ring(indio_dev->ring);
|
||||
struct iio_ring_buffer *ring = indio_dev->ring;
|
||||
s64 time_ns;
|
||||
__u8 *buf;
|
||||
int b_sent;
|
||||
size_t d_size;
|
||||
|
||||
unsigned int bytes = ring->scan_count * st->chip_info->storagebits / 8;
|
||||
|
||||
/* Ensure the timestamp is 8 byte aligned */
|
||||
d_size = bytes + 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;
|
||||
|
||||
buf = kzalloc(d_size, GFP_KERNEL);
|
||||
if (buf == NULL)
|
||||
return;
|
||||
|
||||
b_sent = spi_sync(st->spi, st->ring_msg);
|
||||
if (b_sent)
|
||||
goto done;
|
||||
|
||||
time_ns = iio_get_time_ns();
|
||||
|
||||
memcpy(buf, st->data, bytes);
|
||||
memcpy(buf + d_size - sizeof(s64), &time_ns, sizeof(time_ns));
|
||||
|
||||
indio_dev->ring->access.store_to(&sw_ring->buf, buf, time_ns);
|
||||
done:
|
||||
kfree(buf);
|
||||
atomic_dec(&st->protect_ring);
|
||||
}
|
||||
|
||||
int ad7887_register_ring_funcs_and_init(struct iio_dev *indio_dev)
|
||||
{
|
||||
struct ad7887_state *st = indio_dev->dev_data;
|
||||
int ret;
|
||||
|
||||
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(&indio_dev->ring->access);
|
||||
ret = iio_alloc_pollfunc(indio_dev, NULL, &ad7887_poll_func_th);
|
||||
if (ret)
|
||||
goto error_deallocate_sw_rb;
|
||||
|
||||
/* Ring buffer functions - here trigger setup related */
|
||||
|
||||
indio_dev->ring->preenable = &ad7887_ring_preenable;
|
||||
indio_dev->ring->postenable = &iio_triggered_ring_postenable;
|
||||
indio_dev->ring->predisable = &iio_triggered_ring_predisable;
|
||||
indio_dev->ring->postdisable = &ad7887_ring_postdisable;
|
||||
indio_dev->ring->scan_el_attrs = &ad7887_scan_el_group;
|
||||
|
||||
INIT_WORK(&st->poll_work, &ad7887_poll_bh_to_ring);
|
||||
|
||||
/* 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 ad7887_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);
|
||||
}
|
||||
Reference in New Issue