[PATCH 12/12] iio: adc: adi-axi-adc: move to backend framework

From: Nuno Sa via B4 Relay
Date: Tue Nov 21 2023 - 05:18:11 EST

From: Nuno Sa <nuno.sa@xxxxxxxxxx>

Move to the IIO backend framework. Devices supported by adi-axi-adc now
register themselves as backend devices.

Signed-off-by: Nuno Sa <nuno.sa@xxxxxxxxxx>
---
drivers/iio/adc/Kconfig | 1 +
drivers/iio/adc/adi-axi-adc.c | 364 ++++++++----------------------------------
2 files changed, 65 insertions(+), 300 deletions(-)

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index af56df63beff..cc42a3399c63 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -292,6 +292,7 @@ config ADI_AXI_ADC
select IIO_BUFFER
select IIO_BUFFER_HW_CONSUMER
select IIO_BUFFER_DMAENGINE
+ select IIO_BACKEND
depends on HAS_IOMEM
depends on OF
help
diff --git a/drivers/iio/adc/adi-axi-adc.c b/drivers/iio/adc/adi-axi-adc.c
index c247ff1541d2..b2ab2c119efa 100644
--- a/drivers/iio/adc/adi-axi-adc.c
+++ b/drivers/iio/adc/adi-axi-adc.c
@@ -17,13 +17,9 @@
#include <linux/regmap.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>
+#include <linux/iio/backend.h>
+

/*
* Register definitions:
@@ -44,6 +40,7 @@
#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_MASK GENMASK(6, 4)
#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)
@@ -55,286 +52,67 @@
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;
struct regmap *regmap;
};

-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_DMA_MINALIGN);
-}
-EXPORT_SYMBOL_NS_GPL(adi_axi_adc_conv_priv, IIO_ADI_AXI);
-
-static int adi_axi_adc_config_dma_buffer(struct device *dev,
- struct iio_dev *indio_dev)
-{
- 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";
-
- return devm_iio_dmaengine_buffer_setup(indio_dev->dev.parent,
- indio_dev, dma_name);
-}
-
-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_read_avail(struct iio_dev *indio_dev,
- struct iio_chan_spec const *chan,
- const int **vals, int *type, int *length,
- long mask)
-{
- struct adi_axi_adc_state *st = iio_priv(indio_dev);
- struct adi_axi_adc_conv *conv = &st->client->conv;
-
- if (!conv->read_avail)
- return -EOPNOTSUPP;
-
- return conv->read_avail(conv, chan, vals, type, length, 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;
- int ret;
-
- for (i = 0; i < conv->chip_info->num_channels; i++) {
- if (test_bit(i, scan_mask))
- ret = regmap_set_bits(st->regmap,
- ADI_AXI_REG_CHAN_CTRL(i),
- ADI_AXI_REG_CHAN_CTRL_ENABLE);
- else
- ret = regmap_clear_bits(st->regmap,
- ADI_AXI_REG_CHAN_CTRL(i),
- ADI_AXI_REG_CHAN_CTRL_ENABLE);
- if (ret)
- return ret;
- }
-
- 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_DMA_MINALIGN);
- if (sizeof_priv)
- alloc_size += ALIGN(sizeof_priv, IIO_DMA_MINALIGN);
-
- 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(void *conv)
-{
- adi_axi_adc_conv_unregister(conv);
-}
-
-struct adi_axi_adc_conv *devm_adi_axi_adc_conv_register(struct device *dev,
- size_t sizeof_priv)
+static int axi_adc_enable(struct iio_backend *back)
{
- struct adi_axi_adc_conv *conv;
+ struct adi_axi_adc_state *st = iio_backend_get_priv(back);
int ret;

- conv = adi_axi_adc_conv_register(dev, sizeof_priv);
- if (IS_ERR(conv))
- return conv;
-
- ret = devm_add_action_or_reset(dev, devm_adi_axi_adc_conv_release,
- conv);
+ ret = regmap_set_bits(st->regmap, ADI_AXI_REG_RSTN,
+ ADI_AXI_REG_RSTN_MMCM_RSTN);
if (ret)
- return ERR_PTR(ret);
+ return ret;

- return conv;
+ fsleep(10);
+ return regmap_set_bits(st->regmap, ADI_AXI_REG_RSTN,
+ ADI_AXI_REG_RSTN_RSTN | ADI_AXI_REG_RSTN_MMCM_RSTN);
}
-EXPORT_SYMBOL_NS_GPL(devm_adi_axi_adc_conv_register, IIO_ADI_AXI);

-static const struct iio_info adi_axi_adc_info = {
- .read_raw = &adi_axi_adc_read_raw,
- .write_raw = &adi_axi_adc_write_raw,
- .update_scan_mode = &adi_axi_adc_update_scan_mode,
- .read_avail = &adi_axi_adc_read_avail,
-};
-
-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)
+static void axi_adc_disable(struct iio_backend *back)
{
- 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;
+ struct adi_axi_adc_state *st = iio_backend_get_priv(back);

- if (!try_module_get(cl->dev->driver->owner)) {
- mutex_unlock(&registered_clients_lock);
- of_node_put(cln);
- return ERR_PTR(-ENODEV);
- }
-
- get_device(cl->dev);
- cl->info = info;
- mutex_unlock(&registered_clients_lock);
- of_node_put(cln);
- return cl;
- }
-
- mutex_unlock(&registered_clients_lock);
- of_node_put(cln);
-
- return ERR_PTR(-EPROBE_DEFER);
+ regmap_write(st->regmap, ADI_AXI_REG_RSTN, 0);
}

-static int adi_axi_adc_setup_channels(struct device *dev,
- struct adi_axi_adc_state *st)
+static int axi_adc_data_format_set(struct iio_backend *back, unsigned int chan,
+ const struct iio_backend_data_fmt *data)
{
- struct adi_axi_adc_conv *conv = &st->client->conv;
- int i, ret;
+ struct adi_axi_adc_state *st = iio_backend_get_priv(back);
+ u32 val;

- if (conv->preenable_setup) {
- ret = conv->preenable_setup(conv);
- if (ret)
- return ret;
- }
+ if (!data->enable)
+ return regmap_clear_bits(st->regmap,
+ ADI_AXI_REG_CHAN_CTRL(chan),
+ ADI_AXI_REG_CHAN_CTRL_FMT_EN);

- for (i = 0; i < conv->chip_info->num_channels; i++) {
- ret = regmap_write(st->regmap, ADI_AXI_REG_CHAN_CTRL(i),
- ADI_AXI_REG_CHAN_CTRL_DEFAULTS);
- if (ret)
- return ret;
- }
+ val = FIELD_PREP(ADI_AXI_REG_CHAN_CTRL_FMT_EN, true);
+ if (data->sign_extend)
+ val |= FIELD_PREP(ADI_AXI_REG_CHAN_CTRL_FMT_SIGNEXT, true);
+ if (data->type == IIO_BACKEND_OFFSET_BINARY)
+ val |= FIELD_PREP(ADI_AXI_REG_CHAN_CTRL_FMT_TYPE, true);

- return 0;
+ return regmap_update_bits(st->regmap, ADI_AXI_REG_CHAN_CTRL(chan),
+ ADI_AXI_REG_CHAN_CTRL_FMT_MASK, val);
}

-static int axi_adc_reset(struct adi_axi_adc_state *st)
+static int axi_adc_chan_enable(struct iio_backend *back, unsigned int chan)
{
- int ret;
+ struct adi_axi_adc_state *st = iio_backend_get_priv(back);

- ret = regmap_write(st->regmap, ADI_AXI_REG_RSTN, 0);
- if (ret)
- return ret;
-
- mdelay(10);
- ret = regmap_write(st->regmap, ADI_AXI_REG_RSTN,
- ADI_AXI_REG_RSTN_MMCM_RSTN);
- if (ret)
- return ret;
-
- mdelay(10);
- return regmap_write(st->regmap, ADI_AXI_REG_RSTN,
- ADI_AXI_REG_RSTN_RSTN | ADI_AXI_REG_RSTN_MMCM_RSTN);
+ return regmap_set_bits(st->regmap, ADI_AXI_REG_CHAN_CTRL(chan),
+ ADI_AXI_REG_CHAN_CTRL_ENABLE);
}

-static void adi_axi_adc_cleanup(void *data)
+static int axi_adc_chan_disable(struct iio_backend *back, unsigned int chan)
{
- struct adi_axi_adc_client *cl = data;
+ struct adi_axi_adc_state *st = iio_backend_get_priv(back);

- put_device(cl->dev);
- module_put(cl->dev->driver->owner);
+ return regmap_clear_bits(st->regmap, ADI_AXI_REG_CHAN_CTRL(chan),
+ ADI_AXI_REG_CHAN_CTRL_ENABLE);
}

static const struct regmap_config axi_adc_regmap_config = {
@@ -344,33 +122,25 @@ static const struct regmap_config axi_adc_regmap_config = {
.max_register = 0x0800,
};

+static const struct iio_backend_ops adi_axi_adc_generic = {
+ .enable = axi_adc_enable,
+ .disable = axi_adc_disable,
+ .data_format_set = axi_adc_data_format_set,
+ .chan_enable = axi_adc_chan_enable,
+ .chan_disable = axi_adc_chan_disable,
+};
+
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;
void __iomem *base;
- unsigned int ver;
+ unsigned int ver, *expected_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)
+ st = devm_kzalloc(&pdev->dev, sizeof(*st), GFP_KERNEL);
+ if (!st)
return -ENOMEM;

- st = iio_priv(indio_dev);
- st->client = cl;
- cl->state = st;
- mutex_init(&st->lock);
-
base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(base))
return PTR_ERR(base);
@@ -380,9 +150,15 @@ static int adi_axi_adc_probe(struct platform_device *pdev)
if (IS_ERR(st->regmap))
return PTR_ERR(st->regmap);

- conv = &st->client->conv;
+ expected_ver = (unsigned int *)device_get_match_data(&pdev->dev);
+ if (!expected_ver)
+ return -ENODEV;

- ret = axi_adc_reset(st);
+ /*
+ * Force disable the core. Up to the frontend to enable us. And we can
+ * still read/write registers...
+ */
+ ret = regmap_write(st->regmap, ADI_AXI_REG_RSTN, 0);
if (ret)
return ret;

@@ -390,37 +166,23 @@ static int adi_axi_adc_probe(struct platform_device *pdev)
if (ret)
return ret;

- if (cl->info->version > ver) {
+ if (*expected_ver > 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(*expected_ver),
+ ADI_AXI_PCORE_VER_MINOR(*expected_ver),
+ ADI_AXI_PCORE_VER_PATCH(*expected_ver),
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->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);
+ ret = devm_iio_backend_register(&pdev->dev, &adi_axi_adc_generic, st);
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",
+ dev_info(&pdev->dev, "AXI ADC IP core (%d.%.2d.%d) probed\n",
ADI_AXI_PCORE_VER_MAJOR(ver),
ADI_AXI_PCORE_VER_MINOR(ver),
ADI_AXI_PCORE_VER_PATCH(ver));
@@ -428,6 +190,8 @@ static int adi_axi_adc_probe(struct platform_device *pdev)
return 0;
}

+static unsigned int adi_axi_adc_10_0_a_info = ADI_AXI_PCORE_VER(10, 0, 'a');
+
/* 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 },

--
2.42.1