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iio: adc: adi-axi-adc: add support for AXI ADC IP core

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This change adds support for the Analog Devices Generic AXI ADC IP core.
The IP core is used for interfacing with analog-to-digital (ADC) converters
that require either a high-speed serial interface (JESD204B/C) or a source
synchronous parallel interface (LVDS/CMOS).

Usually, some other interface type (i.e SPI) is used as a control interface
for the actual ADC, while the IP core (controlled via this driver), will
interface to the data-lines of the ADC and handle  the streaming of data
into memory via DMA.

Because of this, the AXI ADC driver needs the other SPI-ADC driver to
register with it. The SPI-ADC needs to be register via the SPI framework,
while the AXI ADC registers as a platform driver. The two cannot be ordered
in a hierarchy as both drivers have their own registers, and trying to
organize this [in a hierarchy becomes] problematic when trying to map
memory/registers.

There are some modes where the AXI ADC can operate as standalone ADC, but
those will be implemented at a later point in time.

DocLink: https://wiki.analog.com/resources/fpga/docs/axi_adc_ip

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Michael Hennerich 2020-03-24 15:46:33 +02:00 committed by Jonathan Cameron
parent e0fcca9fbd
commit ef04070692
4 changed files with 567 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
drivers/iio/adc/Kconfig
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@ -246,6 +246,26 @@ config AD799X
To compile this driver as a module, choose M here: the module will be
called ad799x.
config ADI_AXI_ADC
tristate "Analog Devices Generic AXI ADC IP core driver"
select IIO_BUFFER
select IIO_BUFFER_HW_CONSUMER
select IIO_BUFFER_DMAENGINE
help
Say yes here to build support for Analog Devices Generic
AXI ADC IP core. The IP core is used for interfacing with
analog-to-digital (ADC) converters that require either a high-speed
serial interface (JESD204B/C) or a source synchronous parallel
interface (LVDS/CMOS).
Typically (for such devices) SPI will be used for configuration only,
while this IP core handles the streaming of data into memory via DMA.
Link: https://wiki.analog.com/resources/fpga/docs/axi_adc_ip
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 adi-axi-adc.
config ASPEED_ADC
tristate "Aspeed ADC"
depends on ARCH_ASPEED || COMPILE_TEST

1
drivers/iio/adc/Makefile
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@ -26,6 +26,7 @@ obj-$(CONFIG_AD7793) += ad7793.o
obj-$(CONFIG_AD7887) += ad7887.o
obj-$(CONFIG_AD7949) += ad7949.o
obj-$(CONFIG_AD799X) += ad799x.o
obj-$(CONFIG_ADI_AXI_ADC) += adi-axi-adc.o
obj-$(CONFIG_ASPEED_ADC) += aspeed_adc.o
obj-$(CONFIG_AT91_ADC) += at91_adc.o
obj-$(CONFIG_AT91_SAMA5D2_ADC) += at91-sama5d2_adc.o

482
drivers/iio/adc/adi-axi-adc.c Normal file
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@ -0,0 +1,482 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
* Analog Devices Generic AXI ADC IP core
* Link: https://wiki.analog.com/resources/fpga/docs/axi_adc_ip
*
* Copyright 2012-2020 Analog Devices Inc.
*/
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/buffer-dmaengine.h>
#include <linux/fpga/adi-axi-common.h>
#include <linux/iio/adc/adi-axi-adc.h>
/**
* Register definitions:
* https://wiki.analog.com/resources/fpga/docs/axi_adc_ip#register_map
*/
/* ADC controls */
#define ADI_AXI_REG_RSTN 0x0040
#define ADI_AXI_REG_RSTN_CE_N BIT(2)
#define ADI_AXI_REG_RSTN_MMCM_RSTN BIT(1)
#define ADI_AXI_REG_RSTN_RSTN BIT(0)
/* ADC Channel controls */
#define ADI_AXI_REG_CHAN_CTRL(c) (0x0400 + (c) * 0x40)
#define ADI_AXI_REG_CHAN_CTRL_LB_OWR BIT(11)
#define ADI_AXI_REG_CHAN_CTRL_PN_SEL_OWR BIT(10)
#define ADI_AXI_REG_CHAN_CTRL_IQCOR_EN BIT(9)
#define ADI_AXI_REG_CHAN_CTRL_DCFILT_EN BIT(8)
#define ADI_AXI_REG_CHAN_CTRL_FMT_SIGNEXT BIT(6)
#define ADI_AXI_REG_CHAN_CTRL_FMT_TYPE BIT(5)
#define ADI_AXI_REG_CHAN_CTRL_FMT_EN BIT(4)
#define ADI_AXI_REG_CHAN_CTRL_PN_TYPE_OWR BIT(1)
#define ADI_AXI_REG_CHAN_CTRL_ENABLE BIT(0)
#define ADI_AXI_REG_CHAN_CTRL_DEFAULTS \
(ADI_AXI_REG_CHAN_CTRL_FMT_SIGNEXT | \
ADI_AXI_REG_CHAN_CTRL_FMT_EN | \
ADI_AXI_REG_CHAN_CTRL_ENABLE)
struct adi_axi_adc_core_info {
unsigned int version;
};
struct adi_axi_adc_state {
struct mutex lock;
struct adi_axi_adc_client *client;
void __iomem *regs;
};
struct adi_axi_adc_client {
struct list_head entry;
struct adi_axi_adc_conv conv;
struct adi_axi_adc_state *state;
struct device *dev;
const struct adi_axi_adc_core_info *info;
};
static LIST_HEAD(registered_clients);
static DEFINE_MUTEX(registered_clients_lock);
static struct adi_axi_adc_client *conv_to_client(struct adi_axi_adc_conv *conv)
{
return container_of(conv, struct adi_axi_adc_client, conv);
}
void *adi_axi_adc_conv_priv(struct adi_axi_adc_conv *conv)
{
struct adi_axi_adc_client *cl = conv_to_client(conv);
return (char *)cl + ALIGN(sizeof(struct adi_axi_adc_client), IIO_ALIGN);
}
EXPORT_SYMBOL_GPL(adi_axi_adc_conv_priv);
static void adi_axi_adc_write(struct adi_axi_adc_state *st,
unsigned int reg,
unsigned int val)
{
iowrite32(val, st->regs + reg);
}
static unsigned int adi_axi_adc_read(struct adi_axi_adc_state *st,
unsigned int reg)
{
return ioread32(st->regs + reg);
}
static int adi_axi_adc_config_dma_buffer(struct device *dev,
struct iio_dev *indio_dev)
{
struct iio_buffer *buffer;
const char *dma_name;
if (!device_property_present(dev, "dmas"))
return 0;
if (device_property_read_string(dev, "dma-names", &dma_name))
dma_name = "rx";
buffer = devm_iio_dmaengine_buffer_alloc(indio_dev->dev.parent,
dma_name);
if (IS_ERR(buffer))
return PTR_ERR(buffer);
indio_dev->modes |= INDIO_BUFFER_HARDWARE;
iio_device_attach_buffer(indio_dev, buffer);
return 0;
}
static int adi_axi_adc_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct adi_axi_adc_state *st = iio_priv(indio_dev);
struct adi_axi_adc_conv *conv = &st->client->conv;
if (!conv->read_raw)
return -EOPNOTSUPP;
return conv->read_raw(conv, chan, val, val2, mask);
}
static int adi_axi_adc_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct adi_axi_adc_state *st = iio_priv(indio_dev);
struct adi_axi_adc_conv *conv = &st->client->conv;
if (!conv->write_raw)
return -EOPNOTSUPP;
return conv->write_raw(conv, chan, val, val2, mask);
}
static int adi_axi_adc_update_scan_mode(struct iio_dev *indio_dev,
const unsigned long *scan_mask)
{
struct adi_axi_adc_state *st = iio_priv(indio_dev);
struct adi_axi_adc_conv *conv = &st->client->conv;
unsigned int i, ctrl;
for (i = 0; i < conv->chip_info->num_channels; i++) {
ctrl = adi_axi_adc_read(st, ADI_AXI_REG_CHAN_CTRL(i));
if (test_bit(i, scan_mask))
ctrl |= ADI_AXI_REG_CHAN_CTRL_ENABLE;
else
ctrl &= ~ADI_AXI_REG_CHAN_CTRL_ENABLE;
adi_axi_adc_write(st, ADI_AXI_REG_CHAN_CTRL(i), ctrl);
}
return 0;
}
static struct adi_axi_adc_conv *adi_axi_adc_conv_register(struct device *dev,
size_t sizeof_priv)
{
struct adi_axi_adc_client *cl;
size_t alloc_size;
alloc_size = ALIGN(sizeof(struct adi_axi_adc_client), IIO_ALIGN);
if (sizeof_priv)
alloc_size += ALIGN(sizeof_priv, IIO_ALIGN);
cl = kzalloc(alloc_size, GFP_KERNEL);
if (!cl)
return ERR_PTR(-ENOMEM);
mutex_lock(&registered_clients_lock);
cl->dev = get_device(dev);
list_add_tail(&cl->entry, &registered_clients);
mutex_unlock(&registered_clients_lock);
return &cl->conv;
}
static void adi_axi_adc_conv_unregister(struct adi_axi_adc_conv *conv)
{
struct adi_axi_adc_client *cl = conv_to_client(conv);
mutex_lock(&registered_clients_lock);
list_del(&cl->entry);
put_device(cl->dev);
mutex_unlock(&registered_clients_lock);
kfree(cl);
}
static void devm_adi_axi_adc_conv_release(struct device *dev, void *res)
{
adi_axi_adc_conv_unregister(*(struct adi_axi_adc_conv **)res);
}
struct adi_axi_adc_conv *devm_adi_axi_adc_conv_register(struct device *dev,
size_t sizeof_priv)
{
struct adi_axi_adc_conv **ptr, *conv;
ptr = devres_alloc(devm_adi_axi_adc_conv_release, sizeof(*ptr),
GFP_KERNEL);
if (!ptr)
return ERR_PTR(-ENOMEM);
conv = adi_axi_adc_conv_register(dev, sizeof_priv);
if (IS_ERR(conv)) {
devres_free(ptr);
return ERR_CAST(conv);
}
*ptr = conv;
devres_add(dev, ptr);
return conv;
}
EXPORT_SYMBOL_GPL(devm_adi_axi_adc_conv_register);
static ssize_t in_voltage_scale_available_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct adi_axi_adc_state *st = iio_priv(indio_dev);
struct adi_axi_adc_conv *conv = &st->client->conv;
size_t len = 0;
int i;
for (i = 0; i < conv->chip_info->num_scales; i++) {
const unsigned int *s = conv->chip_info->scale_table[i];
len += scnprintf(buf + len, PAGE_SIZE - len,
"%u.%06u ", s[0], s[1]);
}
buf[len - 1] = '\n';
return len;
}
static IIO_DEVICE_ATTR_RO(in_voltage_scale_available, 0);
enum {
ADI_AXI_ATTR_SCALE_AVAIL,
};
#define ADI_AXI_ATTR(_en_, _file_) \
[ADI_AXI_ATTR_##_en_] = &iio_dev_attr_##_file_.dev_attr.attr
static struct attribute *adi_axi_adc_attributes[] = {
ADI_AXI_ATTR(SCALE_AVAIL, in_voltage_scale_available),
NULL
};
static umode_t axi_adc_attr_is_visible(struct kobject *kobj,
struct attribute *attr, int n)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct adi_axi_adc_state *st = iio_priv(indio_dev);
struct adi_axi_adc_conv *conv = &st->client->conv;
switch (n) {
case ADI_AXI_ATTR_SCALE_AVAIL:
if (!conv->chip_info->num_scales)
return 0;
return attr->mode;
default:
return attr->mode;
}
}
static const struct attribute_group adi_axi_adc_attribute_group = {
.attrs = adi_axi_adc_attributes,
.is_visible = axi_adc_attr_is_visible,
};
static const struct iio_info adi_axi_adc_info = {
.read_raw = &adi_axi_adc_read_raw,
.write_raw = &adi_axi_adc_write_raw,
.attrs = &adi_axi_adc_attribute_group,
.update_scan_mode = &adi_axi_adc_update_scan_mode,
};
static const struct adi_axi_adc_core_info adi_axi_adc_10_0_a_info = {
.version = ADI_AXI_PCORE_VER(10, 0, 'a'),
};
static struct adi_axi_adc_client *adi_axi_adc_attach_client(struct device *dev)
{
const struct adi_axi_adc_core_info *info;
struct adi_axi_adc_client *cl;
struct device_node *cln;
info = of_device_get_match_data(dev);
if (!info)
return ERR_PTR(-ENODEV);
cln = of_parse_phandle(dev->of_node, "adi,adc-dev", 0);
if (!cln) {
dev_err(dev, "No 'adi,adc-dev' node defined\n");
return ERR_PTR(-ENODEV);
}
mutex_lock(&registered_clients_lock);
list_for_each_entry(cl, &registered_clients, entry) {
if (!cl->dev)
continue;
if (cl->dev->of_node != cln)
continue;
if (!try_module_get(dev->driver->owner)) {
mutex_unlock(&registered_clients_lock);
return ERR_PTR(-ENODEV);
}
get_device(dev);
cl->info = info;
mutex_unlock(&registered_clients_lock);
return cl;
}
mutex_unlock(&registered_clients_lock);
return ERR_PTR(-EPROBE_DEFER);
}
static int adi_axi_adc_setup_channels(struct device *dev,
struct adi_axi_adc_state *st)
{
struct adi_axi_adc_conv *conv = &st->client->conv;
int i, ret;
if (conv->preenable_setup) {
ret = conv->preenable_setup(conv);
if (ret)
return ret;
}
for (i = 0; i < conv->chip_info->num_channels; i++) {
adi_axi_adc_write(st, ADI_AXI_REG_CHAN_CTRL(i),
ADI_AXI_REG_CHAN_CTRL_DEFAULTS);
}
return 0;
}
static void axi_adc_reset(struct adi_axi_adc_state *st)
{
adi_axi_adc_write(st, ADI_AXI_REG_RSTN, 0);
mdelay(10);
adi_axi_adc_write(st, ADI_AXI_REG_RSTN, ADI_AXI_REG_RSTN_MMCM_RSTN);
mdelay(10);
adi_axi_adc_write(st, ADI_AXI_REG_RSTN,
ADI_AXI_REG_RSTN_RSTN | ADI_AXI_REG_RSTN_MMCM_RSTN);
}
static void adi_axi_adc_cleanup(void *data)
{
struct adi_axi_adc_client *cl = data;
put_device(cl->dev);
module_put(cl->dev->driver->owner);
}
static int adi_axi_adc_probe(struct platform_device *pdev)
{
struct adi_axi_adc_conv *conv;
struct iio_dev *indio_dev;
struct adi_axi_adc_client *cl;
struct adi_axi_adc_state *st;
unsigned int ver;
int ret;
cl = adi_axi_adc_attach_client(&pdev->dev);
if (IS_ERR(cl))
return PTR_ERR(cl);
ret = devm_add_action_or_reset(&pdev->dev, adi_axi_adc_cleanup, cl);
if (ret)
return ret;
indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
if (indio_dev == NULL)
return -ENOMEM;
st = iio_priv(indio_dev);
st->client = cl;
cl->state = st;
mutex_init(&st->lock);
st->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(st->regs))
return PTR_ERR(st->regs);
conv = &st->client->conv;
axi_adc_reset(st);
ver = adi_axi_adc_read(st, ADI_AXI_REG_VERSION);
if (cl->info->version > ver) {
dev_err(&pdev->dev,
"IP core version is too old. Expected %d.%.2d.%c, Reported %d.%.2d.%c\n",
ADI_AXI_PCORE_VER_MAJOR(cl->info->version),
ADI_AXI_PCORE_VER_MINOR(cl->info->version),
ADI_AXI_PCORE_VER_PATCH(cl->info->version),
ADI_AXI_PCORE_VER_MAJOR(ver),
ADI_AXI_PCORE_VER_MINOR(ver),
ADI_AXI_PCORE_VER_PATCH(ver));
return -ENODEV;
}
indio_dev->info = &adi_axi_adc_info;
indio_dev->dev.parent = &pdev->dev;
indio_dev->name = "adi-axi-adc";
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->num_channels = conv->chip_info->num_channels;
indio_dev->channels = conv->chip_info->channels;
ret = adi_axi_adc_config_dma_buffer(&pdev->dev, indio_dev);
if (ret)
return ret;
ret = adi_axi_adc_setup_channels(&pdev->dev, st);
if (ret)
return ret;
ret = devm_iio_device_register(&pdev->dev, indio_dev);
if (ret)
return ret;
dev_info(&pdev->dev, "AXI ADC IP core (%d.%.2d.%c) probed\n",
ADI_AXI_PCORE_VER_MAJOR(ver),
ADI_AXI_PCORE_VER_MINOR(ver),
ADI_AXI_PCORE_VER_PATCH(ver));
return 0;
}
/* Match table for of_platform binding */
static const struct of_device_id adi_axi_adc_of_match[] = {
{ .compatible = "adi,axi-adc-10.0.a", .data = &adi_axi_adc_10_0_a_info },
{ /* end of list */ }
};
MODULE_DEVICE_TABLE(of, adi_axi_adc_of_match);
static struct platform_driver adi_axi_adc_driver = {
.driver = {
.name = KBUILD_MODNAME,
.of_match_table = adi_axi_adc_of_match,
},
.probe = adi_axi_adc_probe,
};
module_platform_driver(adi_axi_adc_driver);
MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("Analog Devices Generic AXI ADC IP core driver");
MODULE_LICENSE("GPL v2");

64
include/linux/iio/adc/adi-axi-adc.h Normal file
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@ -0,0 +1,64 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Analog Devices Generic AXI ADC IP core driver/library
* Link: https://wiki.analog.com/resources/fpga/docs/axi_adc_ip
*
* Copyright 2012-2020 Analog Devices Inc.
*/
#ifndef __ADI_AXI_ADC_H__
#define __ADI_AXI_ADC_H__
struct device;
struct iio_chan_spec;
/**
* struct adi_axi_adc_chip_info - Chip specific information
* @name Chip name
* @id Chip ID (usually product ID)
* @channels Channel specifications of type @struct axi_adc_chan_spec
* @num_channels Number of @channels
* @scale_table Supported scales by the chip; tuples of 2 ints
* @num_scales Number of scales in the table
* @max_rate Maximum sampling rate supported by the device
*/
struct adi_axi_adc_chip_info {
const char *name;
unsigned int id;
const struct iio_chan_spec *channels;
unsigned int num_channels;
const unsigned int (*scale_table)[2];
int num_scales;
unsigned long max_rate;
};
/**
* struct adi_axi_adc_conv - data of the ADC attached to the AXI ADC
* @chip_info chip info details for the client ADC
* @preenable_setup op to run in the client before enabling the AXI ADC
* @reg_access IIO debugfs_reg_access hook for the client ADC
* @read_raw IIO read_raw hook for the client ADC
* @write_raw IIO write_raw hook for the client ADC
*/
struct adi_axi_adc_conv {
const struct adi_axi_adc_chip_info *chip_info;
int (*preenable_setup)(struct adi_axi_adc_conv *conv);
int (*reg_access)(struct adi_axi_adc_conv *conv, unsigned int reg,
unsigned int writeval, unsigned int *readval);
int (*read_raw)(struct adi_axi_adc_conv *conv,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask);
int (*write_raw)(struct adi_axi_adc_conv *conv,
struct iio_chan_spec const *chan,
int val, int val2, long mask);
};
struct adi_axi_adc_conv *devm_adi_axi_adc_conv_register(struct device *dev,
size_t sizeof_priv);
void *adi_axi_adc_conv_priv(struct adi_axi_adc_conv *conv);
#endif