[PATCH v4 5/5] iio: dac: ad3552r-hs: add support for internal ramp
From: Angelo Dureghello
Date: Tue Apr 08 2025 - 06:24:42 EST
From: Angelo Dureghello <adureghello@xxxxxxxxxxxx>
The ad3552r can be feeded from the HDL controller by an internally
generated 16bit ramp, useful for debug pourposes. Add debugfs a file
to enable or disable it.
Signed-off-by: Angelo Dureghello <adureghello@xxxxxxxxxxxx>
---
drivers/iio/dac/ad3552r-hs.c | 166 +++++++++++++++++++++++++++++++++++++++++--
1 file changed, 160 insertions(+), 6 deletions(-)
diff --git a/drivers/iio/dac/ad3552r-hs.c b/drivers/iio/dac/ad3552r-hs.c
index 37397e188f225a8099745ec03f7c604da76960b1..9a8eed7a06e4f2e7b23d59764b8f2fc21e2c4537 100644
--- a/drivers/iio/dac/ad3552r-hs.c
+++ b/drivers/iio/dac/ad3552r-hs.c
@@ -7,6 +7,7 @@
*/
#include <linux/bitfield.h>
+#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/iio/backend.h>
@@ -54,6 +55,18 @@ struct ad3552r_hs_state {
struct ad3552r_hs_platform_data *data;
/* INTERFACE_CONFIG_D register cache, in DDR we cannot read values. */
u32 config_d;
+ /* Protects backend I/O operations from concurrent accesses. */
+ struct mutex lock;
+};
+
+enum ad3552r_sources {
+ AD3552R_SRC_IIO_BUFFER,
+ AD3552R_SRC_BACKEND_RAMP_GEN,
+};
+
+static const char * const dbgfs_attr_source[] = {
+ [AD3552R_SRC_IIO_BUFFER] = "iio-buffer",
+ [AD3552R_SRC_BACKEND_RAMP_GEN] = "backend-ramp-generator",
};
static int ad3552r_hs_reg_read(struct ad3552r_hs_state *st, u32 reg, u32 *val,
@@ -65,6 +78,20 @@ static int ad3552r_hs_reg_read(struct ad3552r_hs_state *st, u32 reg, u32 *val,
return st->data->bus_reg_read(st->back, reg, val, xfer_size);
}
+static int ad3552r_hs_set_data_source(struct ad3552r_hs_state *st,
+ enum iio_backend_data_source type)
+{
+ int i, ret;
+
+ for (i = 0; i < st->model_data->num_hw_channels; ++i) {
+ ret = iio_backend_data_source_set(st->back, i, type);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
static int ad3552r_hs_update_reg_bits(struct ad3552r_hs_state *st, u32 reg,
u32 mask, u32 val, size_t xfer_size)
{
@@ -483,6 +510,107 @@ static int ad3552r_hs_reg_access(struct iio_dev *indio_dev, unsigned int reg,
return st->data->bus_reg_write(st->back, reg, writeval, 1);
}
+static ssize_t ad3552r_hs_show_data_source(struct file *f, char __user *userbuf,
+ size_t count, loff_t *ppos)
+{
+ struct ad3552r_hs_state *st = file_inode(f)->i_private;
+ enum iio_backend_data_source type;
+ int idx, ret;
+
+ guard(mutex)(&st->lock);
+
+ ret = iio_backend_data_source_get(st->back, 0, &type);
+ if (ret)
+ return ret;
+
+ switch (type) {
+ case IIO_BACKEND_INTERNAL_RAMP_16BIT:
+ idx = AD3552R_SRC_BACKEND_RAMP_GEN;
+ break;
+ case IIO_BACKEND_EXTERNAL:
+ idx = AD3552R_SRC_IIO_BUFFER;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return simple_read_from_buffer(userbuf, count, ppos,
+ dbgfs_attr_source[idx],
+ strlen(dbgfs_attr_source[idx]));
+}
+
+static ssize_t ad3552r_hs_write_data_source(struct file *f,
+ const char __user *userbuf,
+ size_t count, loff_t *ppos)
+{
+ struct ad3552r_hs_state *st = file_inode(f)->i_private;
+ char buf[64];
+ int ret, source;
+
+ guard(mutex)(&st->lock);
+
+ ret = simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, userbuf,
+ count);
+ if (ret < 0)
+ return ret;
+
+ buf[count] = '\0';
+
+ ret = match_string(dbgfs_attr_source, ARRAY_SIZE(dbgfs_attr_source),
+ buf);
+ if (ret < 0)
+ return ret;
+
+ switch (ret) {
+ case AD3552R_SRC_BACKEND_RAMP_GEN:
+ source = IIO_BACKEND_INTERNAL_RAMP_16BIT;
+ break;
+ case AD3552R_SRC_IIO_BUFFER:
+ source = IIO_BACKEND_EXTERNAL;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ ret = ad3552r_hs_set_data_source(st, source);
+ if (ret)
+ return ret;
+
+ return count;
+}
+
+static ssize_t ad3552r_hs_show_data_source_avail(struct file *f,
+ char __user *userbuf,
+ size_t count, loff_t *ppos)
+{
+ ssize_t len = 0;
+ char *buf;
+ int i;
+
+ buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ for (i = 0; i < ARRAY_SIZE(dbgfs_attr_source); i++) {
+ len += scnprintf(buf + len, PAGE_SIZE - len, "%s ",
+ dbgfs_attr_source[i]);
+ }
+ buf[len - 1] = '\n';
+
+ return simple_read_from_buffer(userbuf, count, ppos, buf, len);
+}
+
+static const struct file_operations ad3552r_hs_data_source_fops = {
+ .owner = THIS_MODULE,
+ .write = ad3552r_hs_write_data_source,
+ .read = ad3552r_hs_show_data_source,
+};
+
+static const struct file_operations ad3552r_hs_data_source_avail_fops = {
+ .owner = THIS_MODULE,
+ .read = ad3552r_hs_show_data_source_avail,
+};
+
static int ad3552r_hs_setup(struct ad3552r_hs_state *st)
{
u16 id;
@@ -550,11 +678,7 @@ static int ad3552r_hs_setup(struct ad3552r_hs_state *st)
if (ret)
return ret;
- ret = iio_backend_data_source_set(st->back, 0, IIO_BACKEND_EXTERNAL);
- if (ret)
- return ret;
-
- ret = iio_backend_data_source_set(st->back, 1, IIO_BACKEND_EXTERNAL);
+ ret = ad3552r_hs_set_data_source(st, IIO_BACKEND_EXTERNAL);
if (ret)
return ret;
@@ -661,6 +785,26 @@ static const struct iio_info ad3552r_hs_info = {
.debugfs_reg_access = &ad3552r_hs_reg_access,
};
+static void ad3552r_hs_debugfs_init(struct iio_dev *indio_dev)
+{
+ struct ad3552r_hs_state *st = iio_priv(indio_dev);
+ struct dentry *d = iio_get_debugfs_dentry(indio_dev);
+
+ if (!IS_ENABLED(CONFIG_DEBUG_FS))
+ return;
+
+ d = iio_get_debugfs_dentry(indio_dev);
+ if (!d) {
+ dev_warn(st->dev, "can't set debugfs in driver dir\n");
+ return;
+ }
+
+ debugfs_create_file("data_source", 0600, d, st,
+ &ad3552r_hs_data_source_fops);
+ debugfs_create_file("data_source_available", 0600, d, st,
+ &ad3552r_hs_data_source_avail_fops);
+}
+
static int ad3552r_hs_probe(struct platform_device *pdev)
{
struct ad3552r_hs_state *st;
@@ -705,7 +849,17 @@ static int ad3552r_hs_probe(struct platform_device *pdev)
if (ret)
return ret;
- return devm_iio_device_register(&pdev->dev, indio_dev);
+ ret = devm_iio_device_register(&pdev->dev, indio_dev);
+ if (ret)
+ return ret;
+
+ ret = devm_mutex_init(&pdev->dev, &st->lock);
+ if (ret)
+ return ret;
+
+ ad3552r_hs_debugfs_init(indio_dev);
+
+ return ret;
}
static const struct of_device_id ad3552r_hs_of_id[] = {
--
2.49.0