mirror of
https://github.com/edk2-porting/linux-next.git
synced 2025-01-04 03:33:58 +08:00
staging: IIO: ADC: New driver for the AD7780 / AD7781 24-bit Sigma-Delta ADC
Changes since v1: IIO: ADC: AD7780: Apply review feedback Abort probe() with error in case platform_data is not present. Add comment explaining power down reset (PDRST) GPIO handling and dual function DOUT/RDY interrupt usage. 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
8a789f8c30
commit
d6f087ec9c
@ -142,6 +142,17 @@ config AD7887
|
||||
To compile this driver as a module, choose M here: the
|
||||
module will be called ad7887.
|
||||
|
||||
config AD7780
|
||||
tristate "Analog Devices AD7780 AD7781 ADC driver"
|
||||
depends on SPI
|
||||
help
|
||||
Say yes here to build support for Analog Devices
|
||||
AD7780 and AD7781 SPI analog to digital convertors (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 ad7780.
|
||||
|
||||
config AD7745
|
||||
tristate "Analog Devices AD7745, AD7746 AD7747 capacitive sensor driver"
|
||||
depends on I2C
|
||||
|
||||
@ -34,6 +34,7 @@ obj-$(CONFIG_AD7152) += ad7152.o
|
||||
obj-$(CONFIG_AD7291) += ad7291.o
|
||||
obj-$(CONFIG_AD7314) += ad7314.o
|
||||
obj-$(CONFIG_AD7745) += ad7745.o
|
||||
obj-$(CONFIG_AD7780) += ad7780.o
|
||||
obj-$(CONFIG_AD7816) += ad7816.o
|
||||
obj-$(CONFIG_ADT75) += adt75.o
|
||||
obj-$(CONFIG_ADT7310) += adt7310.o
|
||||
|
||||
329
drivers/staging/iio/adc/ad7780.c
Normal file
329
drivers/staging/iio/adc/ad7780.c
Normal file
@ -0,0 +1,329 @@
|
||||
/*
|
||||
* AD7780/AD7781 SPI ADC driver
|
||||
*
|
||||
* Copyright 2011 Analog Devices Inc.
|
||||
*
|
||||
* Licensed under the GPL-2.
|
||||
*/
|
||||
|
||||
#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 <linux/sched.h>
|
||||
#include <linux/gpio.h>
|
||||
|
||||
#include "../iio.h"
|
||||
#include "../sysfs.h"
|
||||
#include "../ring_generic.h"
|
||||
#include "adc.h"
|
||||
|
||||
#include "ad7780.h"
|
||||
|
||||
#define AD7780_RDY (1 << 7)
|
||||
#define AD7780_FILTER (1 << 6)
|
||||
#define AD7780_ERR (1 << 5)
|
||||
#define AD7780_ID1 (1 << 4)
|
||||
#define AD7780_ID0 (1 << 3)
|
||||
#define AD7780_GAIN (1 << 2)
|
||||
#define AD7780_PAT1 (1 << 1)
|
||||
#define AD7780_PAT0 (1 << 0)
|
||||
|
||||
struct ad7780_chip_info {
|
||||
u8 bits;
|
||||
u8 storagebits;
|
||||
u8 res_shift;
|
||||
};
|
||||
|
||||
struct ad7780_state {
|
||||
struct iio_dev *indio_dev;
|
||||
struct spi_device *spi;
|
||||
const struct ad7780_chip_info *chip_info;
|
||||
struct regulator *reg;
|
||||
struct ad7780_platform_data *pdata;
|
||||
wait_queue_head_t wq_data_avail;
|
||||
bool done;
|
||||
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 int data ____cacheline_aligned;
|
||||
};
|
||||
|
||||
enum ad7780_supported_device_ids {
|
||||
ID_AD7780,
|
||||
ID_AD7781,
|
||||
};
|
||||
|
||||
static int ad7780_read(struct ad7780_state *st, int *val)
|
||||
{
|
||||
int ret;
|
||||
|
||||
spi_bus_lock(st->spi->master);
|
||||
|
||||
enable_irq(st->spi->irq);
|
||||
st->done = false;
|
||||
gpio_set_value(st->pdata->gpio_pdrst, 1);
|
||||
|
||||
ret = wait_event_interruptible(st->wq_data_avail, st->done);
|
||||
disable_irq_nosync(st->spi->irq);
|
||||
if (ret)
|
||||
goto out;
|
||||
|
||||
ret = spi_sync_locked(st->spi, &st->msg);
|
||||
*val = be32_to_cpu(st->data);
|
||||
out:
|
||||
gpio_set_value(st->pdata->gpio_pdrst, 0);
|
||||
spi_bus_unlock(st->spi->master);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static ssize_t ad7780_scan(struct device *dev,
|
||||
struct device_attribute *attr,
|
||||
char *buf)
|
||||
{
|
||||
struct iio_dev *dev_info = dev_get_drvdata(dev);
|
||||
struct ad7780_state *st = dev_info->dev_data;
|
||||
int ret, val, smpl;
|
||||
|
||||
mutex_lock(&dev_info->mlock);
|
||||
ret = ad7780_read(st, &smpl);
|
||||
mutex_unlock(&dev_info->mlock);
|
||||
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
if ((smpl & AD7780_ERR) ||
|
||||
!((smpl & AD7780_PAT0) && !(smpl & AD7780_PAT1)))
|
||||
return -EIO;
|
||||
|
||||
val = (smpl >> st->chip_info->res_shift) &
|
||||
((1 << (st->chip_info->bits)) - 1);
|
||||
val -= (1 << (st->chip_info->bits - 1));
|
||||
|
||||
if (!(smpl & AD7780_GAIN))
|
||||
val *= 128;
|
||||
|
||||
return sprintf(buf, "%d\n", val);
|
||||
}
|
||||
static IIO_DEV_ATTR_IN_RAW(0, ad7780_scan, 0);
|
||||
|
||||
static ssize_t ad7780_show_scale(struct device *dev,
|
||||
struct device_attribute *attr,
|
||||
char *buf)
|
||||
{
|
||||
struct iio_dev *dev_info = dev_get_drvdata(dev);
|
||||
struct ad7780_state *st = iio_dev_get_devdata(dev_info);
|
||||
/* Corresponds to Vref / 2^(bits-1) */
|
||||
unsigned int scale = (st->int_vref_mv * 100000) >>
|
||||
(st->chip_info->bits - 1);
|
||||
|
||||
return sprintf(buf, "%d.%05d\n", scale / 100000, scale % 100000);
|
||||
}
|
||||
static IIO_DEVICE_ATTR(in_scale, S_IRUGO, ad7780_show_scale, NULL, 0);
|
||||
|
||||
static ssize_t ad7780_show_name(struct device *dev,
|
||||
struct device_attribute *attr,
|
||||
char *buf)
|
||||
{
|
||||
struct iio_dev *dev_info = dev_get_drvdata(dev);
|
||||
struct ad7780_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, ad7780_show_name, NULL, 0);
|
||||
|
||||
static struct attribute *ad7780_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 ad7780_attribute_group = {
|
||||
.attrs = ad7780_attributes,
|
||||
};
|
||||
|
||||
static const struct ad7780_chip_info ad7780_chip_info_tbl[] = {
|
||||
[ID_AD7780] = {
|
||||
.bits = 24,
|
||||
.storagebits = 32,
|
||||
.res_shift = 8,
|
||||
},
|
||||
[ID_AD7781] = {
|
||||
.bits = 20,
|
||||
.storagebits = 32,
|
||||
.res_shift = 12,
|
||||
},
|
||||
};
|
||||
|
||||
/**
|
||||
* Interrupt handler
|
||||
*/
|
||||
static irqreturn_t ad7780_interrupt(int irq, void *dev_id)
|
||||
{
|
||||
struct ad7780_state *st = dev_id;
|
||||
|
||||
st->done = true;
|
||||
wake_up_interruptible(&st->wq_data_avail);
|
||||
|
||||
return IRQ_HANDLED;
|
||||
};
|
||||
|
||||
static int __devinit ad7780_probe(struct spi_device *spi)
|
||||
{
|
||||
struct ad7780_platform_data *pdata = spi->dev.platform_data;
|
||||
struct ad7780_state *st;
|
||||
int ret, voltage_uv = 0;
|
||||
|
||||
if (!pdata) {
|
||||
dev_dbg(&spi->dev, "no platform data?\n");
|
||||
return -ENODEV;
|
||||
}
|
||||
|
||||
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 =
|
||||
&ad7780_chip_info_tbl[spi_get_device_id(spi)->driver_data];
|
||||
|
||||
st->pdata = pdata;
|
||||
|
||||
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);
|
||||
st->spi = spi;
|
||||
|
||||
st->indio_dev = iio_allocate_device();
|
||||
if (st->indio_dev == NULL) {
|
||||
ret = -ENOMEM;
|
||||
goto error_disable_reg;
|
||||
}
|
||||
|
||||
/* Establish that the iio_dev is a child of the spi device */
|
||||
st->indio_dev->dev.parent = &spi->dev;
|
||||
st->indio_dev->attrs = &ad7780_attribute_group;
|
||||
st->indio_dev->dev_data = (void *)(st);
|
||||
st->indio_dev->driver_module = THIS_MODULE;
|
||||
st->indio_dev->modes = INDIO_DIRECT_MODE;
|
||||
|
||||
init_waitqueue_head(&st->wq_data_avail);
|
||||
|
||||
/* 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 = gpio_request_one(st->pdata->gpio_pdrst, GPIOF_OUT_INIT_LOW,
|
||||
"AD7877 /PDRST");
|
||||
if (ret) {
|
||||
dev_err(&spi->dev, "failed to request GPIO PDRST\n");
|
||||
goto error_free_device;
|
||||
}
|
||||
|
||||
ret = request_irq(spi->irq, ad7780_interrupt,
|
||||
IRQF_TRIGGER_FALLING, spi_get_device_id(spi)->name, st);
|
||||
if (ret)
|
||||
goto error_free_device;
|
||||
|
||||
disable_irq(spi->irq);
|
||||
|
||||
ret = iio_device_register(st->indio_dev);
|
||||
if (ret)
|
||||
goto error_free_irq;
|
||||
|
||||
return 0;
|
||||
|
||||
error_free_irq:
|
||||
free_irq(spi->irq, st);
|
||||
|
||||
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 ad7780_remove(struct spi_device *spi)
|
||||
{
|
||||
struct ad7780_state *st = spi_get_drvdata(spi);
|
||||
struct iio_dev *indio_dev = st->indio_dev;
|
||||
free_irq(spi->irq, st);
|
||||
gpio_free(st->pdata->gpio_pdrst);
|
||||
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 ad7780_id[] = {
|
||||
{"ad7780", ID_AD7780},
|
||||
{"ad7781", ID_AD7781},
|
||||
{}
|
||||
};
|
||||
|
||||
static struct spi_driver ad7780_driver = {
|
||||
.driver = {
|
||||
.name = "ad7780",
|
||||
.bus = &spi_bus_type,
|
||||
.owner = THIS_MODULE,
|
||||
},
|
||||
.probe = ad7780_probe,
|
||||
.remove = __devexit_p(ad7780_remove),
|
||||
.id_table = ad7780_id,
|
||||
};
|
||||
|
||||
static int __init ad7780_init(void)
|
||||
{
|
||||
return spi_register_driver(&ad7780_driver);
|
||||
}
|
||||
module_init(ad7780_init);
|
||||
|
||||
static void __exit ad7780_exit(void)
|
||||
{
|
||||
spi_unregister_driver(&ad7780_driver);
|
||||
}
|
||||
module_exit(ad7780_exit);
|
||||
|
||||
MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
|
||||
MODULE_DESCRIPTION("Analog Devices AD7780/1 ADC");
|
||||
MODULE_LICENSE("GPL v2");
|
||||
30
drivers/staging/iio/adc/ad7780.h
Normal file
30
drivers/staging/iio/adc/ad7780.h
Normal file
@ -0,0 +1,30 @@
|
||||
/*
|
||||
* AD7780/AD7781 SPI ADC driver
|
||||
*
|
||||
* Copyright 2011 Analog Devices Inc.
|
||||
*
|
||||
* Licensed under the GPL-2.
|
||||
*/
|
||||
#ifndef IIO_ADC_AD7780_H_
|
||||
#define IIO_ADC_AD7780_H_
|
||||
|
||||
/*
|
||||
* TODO: struct ad7780_platform_data needs to go into include/linux/iio
|
||||
*/
|
||||
|
||||
/* NOTE:
|
||||
* The AD7780 doesn't feature a dedicated SPI chip select, in addition it
|
||||
* features a dual use data out ready DOUT/RDY output.
|
||||
* In order to avoid contentions on the SPI bus, it's therefore necessary
|
||||
* to use spi bus locking combined with a dedicated GPIO to control the
|
||||
* power down reset signal of the AD7780.
|
||||
*
|
||||
* The DOUT/RDY output must also be wired to an interrupt capable GPIO.
|
||||
*/
|
||||
|
||||
struct ad7780_platform_data {
|
||||
u16 vref_mv;
|
||||
int gpio_pdrst;
|
||||
};
|
||||
|
||||
#endif /* IIO_ADC_AD7780_H_ */
|
||||
Loading…
Reference in New Issue
Block a user