mirror of https://gitee.com/openkylin/linux.git
staging: iio: adc: ad7476 new SPI ADC driver
New driver handling: AD7475, AD7476, AD7477, AD7478, AD7466, AD7467, AD7468, AD7495 SPI micropower and high speed 12-/10-/8-Bit ADCs staging: iio: adc: ad7476 apply list review feedback by Jonathan Cameron Changes since last RFC post V1: Mainly list review feedback by Jonathan Cameron -Remove scan_attrs from chip info structure. -Remove name from chip info structure, use new spi_device_id instead. -Allow transfer buffers to live in their own cache lines, to avoid DMA/cache coherency issues. -Move scan el code into the ring buffer file. -Use helper function to alloc the pollfunc. -Use regulator framework and get vref_mv from the regulator in case not specified by pdata. -Devices with buit-in reference use vref from the chip info structure -Don't error on missing platform_data -Make vref_mv type unsigned short -Print in_scale "Vref / 2^(bits)" if fractional. 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
1dd8b73227
commit
349282d82e
|
|
@ -46,3 +46,14 @@ config AD799X_RING_BUFFER
|
||||||
help
|
help
|
||||||
Say yes here to include ring buffer support in the AD799X
|
Say yes here to include ring buffer support in the AD799X
|
||||||
ADC driver.
|
ADC driver.
|
||||||
|
|
||||||
|
config AD7476
|
||||||
|
tristate "Analog Devices AD7475/6/7/8 AD7466/7/8 and AD7495 ADC driver"
|
||||||
|
depends on SPI
|
||||||
|
help
|
||||||
|
Say yes here to build support for Analog Devices AD7475/6/7/8,
|
||||||
|
AD7466/7/8 and AD7495 ADC driver.
|
||||||
|
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 ad7476.
|
||||||
|
|
|
||||||
|
|
@ -10,3 +10,7 @@ obj-$(CONFIG_MAX1363) += max1363.o
|
||||||
ad799x-y := ad799x_core.o
|
ad799x-y := ad799x_core.o
|
||||||
ad799x-$(CONFIG_AD799X_RING_BUFFER) += ad799x_ring.o
|
ad799x-$(CONFIG_AD799X_RING_BUFFER) += ad799x_ring.o
|
||||||
obj-$(CONFIG_AD799X) += ad799x.o
|
obj-$(CONFIG_AD799X) += ad799x.o
|
||||||
|
|
||||||
|
ad7476-y := ad7476_core.o
|
||||||
|
ad7476-$(CONFIG_IIO_RING_BUFFER) += ad7476_ring.o
|
||||||
|
obj-$(CONFIG_AD7476) += ad7476.o
|
||||||
|
|
|
||||||
|
|
@ -0,0 +1,79 @@
|
||||||
|
/*
|
||||||
|
* AD7476/5/7/8 (A) SPI ADC driver
|
||||||
|
*
|
||||||
|
* Copyright 2010 Analog Devices Inc.
|
||||||
|
*
|
||||||
|
* Licensed under the GPL-2 or later.
|
||||||
|
*/
|
||||||
|
#ifndef IIO_ADC_AD7476_H_
|
||||||
|
#define IIO_ADC_AD7476_H_
|
||||||
|
|
||||||
|
#define RES_MASK(bits) ((1 << (bits)) - 1)
|
||||||
|
|
||||||
|
/*
|
||||||
|
* TODO: struct ad7476_platform_data needs to go into include/linux/iio
|
||||||
|
*/
|
||||||
|
|
||||||
|
struct ad7476_platform_data {
|
||||||
|
u16 vref_mv;
|
||||||
|
};
|
||||||
|
|
||||||
|
struct ad7476_chip_info {
|
||||||
|
u8 bits;
|
||||||
|
u8 storagebits;
|
||||||
|
u8 res_shift;
|
||||||
|
char sign;
|
||||||
|
u16 int_vref_mv;
|
||||||
|
};
|
||||||
|
|
||||||
|
struct ad7476_state {
|
||||||
|
struct iio_dev *indio_dev;
|
||||||
|
struct spi_device *spi;
|
||||||
|
const struct ad7476_chip_info *chip_info;
|
||||||
|
struct regulator *reg;
|
||||||
|
struct work_struct poll_work;
|
||||||
|
atomic_t protect_ring;
|
||||||
|
u16 int_vref_mv;
|
||||||
|
struct spi_transfer xfer;
|
||||||
|
struct spi_message msg;
|
||||||
|
/*
|
||||||
|
* DMA (thus cache coherency maintenance) requires the
|
||||||
|
* transfer buffers to live in their own cache lines.
|
||||||
|
*/
|
||||||
|
unsigned char data[2] ____cacheline_aligned;
|
||||||
|
};
|
||||||
|
|
||||||
|
enum ad7476_supported_device_ids {
|
||||||
|
ID_AD7466,
|
||||||
|
ID_AD7467,
|
||||||
|
ID_AD7468,
|
||||||
|
ID_AD7475,
|
||||||
|
ID_AD7476,
|
||||||
|
ID_AD7477,
|
||||||
|
ID_AD7478,
|
||||||
|
ID_AD7495
|
||||||
|
};
|
||||||
|
|
||||||
|
#ifdef CONFIG_IIO_RING_BUFFER
|
||||||
|
int ad7476_scan_from_ring(struct ad7476_state *st);
|
||||||
|
int ad7476_register_ring_funcs_and_init(struct iio_dev *indio_dev);
|
||||||
|
void ad7476_ring_cleanup(struct iio_dev *indio_dev);
|
||||||
|
#else /* CONFIG_IIO_RING_BUFFER */
|
||||||
|
static inline ssize_t ad7476_scan_from_ring(struct device *dev,
|
||||||
|
struct device_attribute *attr,
|
||||||
|
char *buf)
|
||||||
|
{
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
static inline int
|
||||||
|
ad7476_register_ring_funcs_and_init(struct iio_dev *indio_dev)
|
||||||
|
{
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
static inline void ad7476_ring_cleanup(struct iio_dev *indio_dev)
|
||||||
|
{
|
||||||
|
}
|
||||||
|
#endif /* CONFIG_IIO_RING_BUFFER */
|
||||||
|
#endif /* IIO_ADC_AD7476_H_ */
|
||||||
|
|
@ -0,0 +1,298 @@
|
||||||
|
/*
|
||||||
|
* AD7466/7/8 AD7476/5/7/8 (A) 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 "ad7476.h"
|
||||||
|
|
||||||
|
static int ad7476_scan_direct(struct ad7476_state *st)
|
||||||
|
{
|
||||||
|
struct spi_device *spi = st->spi;
|
||||||
|
int ret;
|
||||||
|
|
||||||
|
ret = spi_sync(spi, &st->msg);
|
||||||
|
if (ret)
|
||||||
|
return ret;
|
||||||
|
|
||||||
|
return (st->data[0] << 8) | st->data[1];
|
||||||
|
}
|
||||||
|
|
||||||
|
static ssize_t ad7476_scan(struct device *dev,
|
||||||
|
struct device_attribute *attr,
|
||||||
|
char *buf)
|
||||||
|
{
|
||||||
|
struct iio_dev *dev_info = dev_get_drvdata(dev);
|
||||||
|
struct ad7476_state *st = dev_info->dev_data;
|
||||||
|
int ret;
|
||||||
|
|
||||||
|
mutex_lock(&dev_info->mlock);
|
||||||
|
if (iio_ring_enabled(dev_info))
|
||||||
|
ret = ad7476_scan_from_ring(st);
|
||||||
|
else
|
||||||
|
ret = ad7476_scan_direct(st);
|
||||||
|
mutex_unlock(&dev_info->mlock);
|
||||||
|
|
||||||
|
if (ret < 0)
|
||||||
|
return ret;
|
||||||
|
|
||||||
|
return sprintf(buf, "%d\n", (ret >> st->chip_info->res_shift) &
|
||||||
|
RES_MASK(st->chip_info->bits));
|
||||||
|
}
|
||||||
|
static IIO_DEV_ATTR_IN_RAW(0, ad7476_scan, 0);
|
||||||
|
|
||||||
|
static ssize_t ad7476_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 ad7476_state *st = iio_dev_get_devdata(dev_info);
|
||||||
|
/* Corresponds to Vref / 2^(bits) */
|
||||||
|
|
||||||
|
if ((1 << (st->chip_info->bits + 1)) > st->int_vref_mv)
|
||||||
|
return sprintf(buf, "%d/2^%d\n",
|
||||||
|
st->int_vref_mv, st->chip_info->bits);
|
||||||
|
else
|
||||||
|
return sprintf(buf, "%d\n",
|
||||||
|
st->int_vref_mv >> st->chip_info->bits);
|
||||||
|
}
|
||||||
|
static IIO_DEVICE_ATTR(in_scale, S_IRUGO, ad7476_show_scale, NULL, 0);
|
||||||
|
|
||||||
|
static ssize_t ad7476_show_name(struct device *dev,
|
||||||
|
struct device_attribute *attr,
|
||||||
|
char *buf)
|
||||||
|
{
|
||||||
|
struct iio_dev *dev_info = dev_get_drvdata(dev);
|
||||||
|
struct ad7476_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, ad7476_show_name, NULL, 0);
|
||||||
|
|
||||||
|
static struct attribute *ad7476_attributes[] = {
|
||||||
|
&iio_dev_attr_in0_raw.dev_attr.attr,
|
||||||
|
&iio_dev_attr_in_scale.dev_attr.attr,
|
||||||
|
&iio_dev_attr_name.dev_attr.attr,
|
||||||
|
NULL,
|
||||||
|
};
|
||||||
|
|
||||||
|
static const struct attribute_group ad7476_attribute_group = {
|
||||||
|
.attrs = ad7476_attributes,
|
||||||
|
};
|
||||||
|
|
||||||
|
static const struct ad7476_chip_info ad7476_chip_info_tbl[] = {
|
||||||
|
[ID_AD7466] = {
|
||||||
|
.bits = 12,
|
||||||
|
.storagebits = 16,
|
||||||
|
.res_shift = 0,
|
||||||
|
.sign = IIO_SCAN_EL_TYPE_UNSIGNED,
|
||||||
|
},
|
||||||
|
[ID_AD7467] = {
|
||||||
|
.bits = 10,
|
||||||
|
.storagebits = 16,
|
||||||
|
.res_shift = 2,
|
||||||
|
.sign = IIO_SCAN_EL_TYPE_UNSIGNED,
|
||||||
|
},
|
||||||
|
[ID_AD7468] = {
|
||||||
|
.bits = 8,
|
||||||
|
.storagebits = 16,
|
||||||
|
.res_shift = 4,
|
||||||
|
.sign = IIO_SCAN_EL_TYPE_UNSIGNED,
|
||||||
|
},
|
||||||
|
[ID_AD7475] = {
|
||||||
|
.bits = 12,
|
||||||
|
.storagebits = 16,
|
||||||
|
.res_shift = 0,
|
||||||
|
.sign = IIO_SCAN_EL_TYPE_UNSIGNED,
|
||||||
|
},
|
||||||
|
[ID_AD7476] = {
|
||||||
|
.bits = 12,
|
||||||
|
.storagebits = 16,
|
||||||
|
.res_shift = 0,
|
||||||
|
.sign = IIO_SCAN_EL_TYPE_UNSIGNED,
|
||||||
|
},
|
||||||
|
[ID_AD7477] = {
|
||||||
|
.bits = 10,
|
||||||
|
.storagebits = 16,
|
||||||
|
.res_shift = 2,
|
||||||
|
.sign = IIO_SCAN_EL_TYPE_UNSIGNED,
|
||||||
|
},
|
||||||
|
[ID_AD7478] = {
|
||||||
|
.bits = 8,
|
||||||
|
.storagebits = 16,
|
||||||
|
.res_shift = 4,
|
||||||
|
.sign = IIO_SCAN_EL_TYPE_UNSIGNED,
|
||||||
|
},
|
||||||
|
[ID_AD7495] = {
|
||||||
|
.bits = 12,
|
||||||
|
.storagebits = 16,
|
||||||
|
.res_shift = 0,
|
||||||
|
.int_vref_mv = 2500,
|
||||||
|
.sign = IIO_SCAN_EL_TYPE_UNSIGNED,
|
||||||
|
},
|
||||||
|
};
|
||||||
|
|
||||||
|
static int __devinit ad7476_probe(struct spi_device *spi)
|
||||||
|
{
|
||||||
|
struct ad7476_platform_data *pdata = spi->dev.platform_data;
|
||||||
|
struct ad7476_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 =
|
||||||
|
&ad7476_chip_info_tbl[spi_get_device_id(spi)->driver_data];
|
||||||
|
|
||||||
|
if (st->chip_info->int_vref_mv)
|
||||||
|
st->int_vref_mv = st->chip_info->int_vref_mv;
|
||||||
|
else 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");
|
||||||
|
|
||||||
|
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 i2c device */
|
||||||
|
st->indio_dev->dev.parent = &spi->dev;
|
||||||
|
st->indio_dev->attrs = &ad7476_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->xfer.rx_buf = &st->data;
|
||||||
|
st->xfer.len = st->chip_info->storagebits / 8;
|
||||||
|
|
||||||
|
spi_message_init(&st->msg);
|
||||||
|
spi_message_add_tail(&st->xfer, &st->msg);
|
||||||
|
|
||||||
|
ret = ad7476_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:
|
||||||
|
ad7476_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 ad7476_remove(struct spi_device *spi)
|
||||||
|
{
|
||||||
|
struct ad7476_state *st = spi_get_drvdata(spi);
|
||||||
|
struct iio_dev *indio_dev = st->indio_dev;
|
||||||
|
iio_ring_buffer_unregister(indio_dev->ring);
|
||||||
|
ad7476_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 ad7476_id[] = {
|
||||||
|
{"ad7466", ID_AD7466},
|
||||||
|
{"ad7467", ID_AD7467},
|
||||||
|
{"ad7468", ID_AD7468},
|
||||||
|
{"ad7475", ID_AD7475},
|
||||||
|
{"ad7476", ID_AD7476},
|
||||||
|
{"ad7476a", ID_AD7476},
|
||||||
|
{"ad7477", ID_AD7477},
|
||||||
|
{"ad7477a", ID_AD7477},
|
||||||
|
{"ad7478", ID_AD7478},
|
||||||
|
{"ad7478a", ID_AD7478},
|
||||||
|
{"ad7495", ID_AD7495},
|
||||||
|
{}
|
||||||
|
};
|
||||||
|
|
||||||
|
static struct spi_driver ad7476_driver = {
|
||||||
|
.driver = {
|
||||||
|
.name = "ad7476",
|
||||||
|
.bus = &spi_bus_type,
|
||||||
|
.owner = THIS_MODULE,
|
||||||
|
},
|
||||||
|
.probe = ad7476_probe,
|
||||||
|
.remove = __devexit_p(ad7476_remove),
|
||||||
|
.id_table = ad7476_id,
|
||||||
|
};
|
||||||
|
|
||||||
|
static int __init ad7476_init(void)
|
||||||
|
{
|
||||||
|
return spi_register_driver(&ad7476_driver);
|
||||||
|
}
|
||||||
|
module_init(ad7476_init);
|
||||||
|
|
||||||
|
static void __exit ad7476_exit(void)
|
||||||
|
{
|
||||||
|
spi_unregister_driver(&ad7476_driver);
|
||||||
|
}
|
||||||
|
module_exit(ad7476_exit);
|
||||||
|
|
||||||
|
MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
|
||||||
|
MODULE_DESCRIPTION("Analog Devices AD7475/6/7/8(A) AD7466/7/8 ADC");
|
||||||
|
MODULE_LICENSE("GPL v2");
|
||||||
|
MODULE_ALIAS("spi:ad7476");
|
||||||
|
|
@ -0,0 +1,207 @@
|
||||||
|
/*
|
||||||
|
* Copyright 2010 Analog Devices Inc.
|
||||||
|
* Copyright (C) 2008 Jonathan Cameron
|
||||||
|
*
|
||||||
|
* Licensed under the GPL-2 or later.
|
||||||
|
*
|
||||||
|
* ad7476_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 "ad7476.h"
|
||||||
|
|
||||||
|
static IIO_SCAN_EL_C(in0, 0, 0, NULL);
|
||||||
|
|
||||||
|
static ssize_t ad7476_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 ad7476_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->res_shift);
|
||||||
|
}
|
||||||
|
static IIO_DEVICE_ATTR(in_type, S_IRUGO, ad7476_show_type, NULL, 0);
|
||||||
|
|
||||||
|
static struct attribute *ad7476_scan_el_attrs[] = {
|
||||||
|
&iio_scan_el_in0.dev_attr.attr,
|
||||||
|
&iio_const_attr_in0_index.dev_attr.attr,
|
||||||
|
&iio_dev_attr_in_type.dev_attr.attr,
|
||||||
|
NULL,
|
||||||
|
};
|
||||||
|
|
||||||
|
static struct attribute_group ad7476_scan_el_group = {
|
||||||
|
.name = "scan_elements",
|
||||||
|
.attrs = ad7476_scan_el_attrs,
|
||||||
|
};
|
||||||
|
|
||||||
|
int ad7476_scan_from_ring(struct ad7476_state *st)
|
||||||
|
{
|
||||||
|
struct iio_ring_buffer *ring = st->indio_dev->ring;
|
||||||
|
int ret;
|
||||||
|
u8 *ring_data;
|
||||||
|
|
||||||
|
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, ring_data);
|
||||||
|
if (ret)
|
||||||
|
goto error_free_ring_data;
|
||||||
|
|
||||||
|
ret = (ring_data[0] << 8) | ring_data[1];
|
||||||
|
|
||||||
|
error_free_ring_data:
|
||||||
|
kfree(ring_data);
|
||||||
|
error_ret:
|
||||||
|
return ret;
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* ad7476_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 ad7476_ring_preenable(struct iio_dev *indio_dev)
|
||||||
|
{
|
||||||
|
struct ad7476_state *st = indio_dev->dev_data;
|
||||||
|
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);
|
||||||
|
}
|
||||||
|
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* ad7476_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 ad7476_poll_func_th(struct iio_dev *indio_dev, s64 time)
|
||||||
|
{
|
||||||
|
struct ad7476_state *st = indio_dev->dev_data;
|
||||||
|
|
||||||
|
schedule_work(&st->poll_work);
|
||||||
|
return;
|
||||||
|
}
|
||||||
|
/**
|
||||||
|
* ad7476_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 ad7476_poll_bh_to_ring(struct work_struct *work_s)
|
||||||
|
{
|
||||||
|
struct ad7476_state *st = container_of(work_s, struct ad7476_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);
|
||||||
|
s64 time_ns;
|
||||||
|
__u8 *rxbuf;
|
||||||
|
int b_sent;
|
||||||
|
size_t d_size;
|
||||||
|
|
||||||
|
/* Ensure the timestamp is 8 byte aligned */
|
||||||
|
d_size = st->chip_info->storagebits / 8 + 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;
|
||||||
|
|
||||||
|
rxbuf = kzalloc(d_size, GFP_KERNEL);
|
||||||
|
if (rxbuf == NULL)
|
||||||
|
return;
|
||||||
|
|
||||||
|
b_sent = spi_read(st->spi, rxbuf, st->chip_info->storagebits / 8);
|
||||||
|
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(&sw_ring->buf, rxbuf, time_ns);
|
||||||
|
done:
|
||||||
|
kfree(rxbuf);
|
||||||
|
atomic_dec(&st->protect_ring);
|
||||||
|
}
|
||||||
|
|
||||||
|
int ad7476_register_ring_funcs_and_init(struct iio_dev *indio_dev)
|
||||||
|
{
|
||||||
|
struct ad7476_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(&indio_dev->ring->access);
|
||||||
|
ret = iio_alloc_pollfunc(indio_dev, NULL, &ad7476_poll_func_th);
|
||||||
|
if (ret)
|
||||||
|
goto error_deallocate_sw_rb;
|
||||||
|
|
||||||
|
/* Ring buffer functions - here trigger setup related */
|
||||||
|
|
||||||
|
indio_dev->ring->preenable = &ad7476_ring_preenable;
|
||||||
|
indio_dev->ring->postenable = &iio_triggered_ring_postenable;
|
||||||
|
indio_dev->ring->predisable = &iio_triggered_ring_predisable;
|
||||||
|
indio_dev->ring->scan_el_attrs = &ad7476_scan_el_group;
|
||||||
|
|
||||||
|
INIT_WORK(&st->poll_work, &ad7476_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 ad7476_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);
|
||||||
|
}
|
||||||
Loading…
Reference in New Issue