[PATCH] iio: dac: ad3552r-hs: add debugfs reg access

[PATCH] iio: dac: ad3552r-hs: add debugfs reg access

[Angelo Dureghello]

From: Angelo Dureghello <adureghello@baylibre.com>

Add debugfs register access.

Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
 drivers/iio/dac/ad3552r-hs.c | 31 +++++++++++++++++++++++++++++++
 drivers/iio/dac/ad3552r.h    |  2 ++
 2 files changed, 33 insertions(+)

diff --git a/drivers/iio/dac/ad3552r-hs.c b/drivers/iio/dac/ad3552r-hs.c
index cd8dabb60c5548780f0fce5d1b68c494cd71321d..7bb6d8817a545f16de9432526ae28787af1a0146 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>
@@ -56,6 +57,15 @@ struct ad3552r_hs_state {
 	u32 config_d;
 };
 
+static int ad3552r_hs_get_reg_length(unsigned int reg)
+{
+	/*
+	 * There is no 3 or 4 bytes r/w len possible in HDL, so keeping 2
+	 * also for the 24bit area.
+	 */
+	return (reg > AD3552R_SECONDARY_REGION_START) ? 2 : 1;
+}
+
 static int ad3552r_hs_reg_read(struct ad3552r_hs_state *st, u32 reg, u32 *val,
 			       size_t xfer_size)
 {
@@ -464,6 +474,26 @@ static int ad3552r_hs_setup_custom_gain(struct ad3552r_hs_state *st,
 				      gain, 1);
 }
 
+static int ad3552r_hs_reg_access(struct iio_dev *indio_dev, unsigned int reg,
+				 unsigned int writeval, unsigned int *readval)
+{
+	struct ad3552r_hs_state *st = iio_priv(indio_dev);
+	int size_xfer, max_reg_addr;
+
+	max_reg_addr = (st->model_data->num_hw_channels == 2) ?
+			AD3552R_REG_ADDR_MAX : AD3551R_REG_ADDR_MAX;
+
+	if (reg > max_reg_addr)
+		return -EINVAL;
+
+	size_xfer = ad3552r_hs_get_reg_length(reg);
+
+	if (readval)
+		return ad3552r_hs_reg_read(st, reg, readval, size_xfer);
+
+	return st->data->bus_reg_write(st->back, reg, writeval, size_xfer);
+}
+
 static int ad3552r_hs_setup(struct ad3552r_hs_state *st)
 {
 	u16 id;
@@ -639,6 +669,7 @@ static const struct iio_chan_spec ad3552r_hs_channels[] = {
 static const struct iio_info ad3552r_hs_info = {
 	.read_raw = &ad3552r_hs_read_raw,
 	.write_raw = &ad3552r_hs_write_raw,
+	.debugfs_reg_access = &ad3552r_hs_reg_access,
 };
 
 static int ad3552r_hs_probe(struct platform_device *pdev)
diff --git a/drivers/iio/dac/ad3552r.h b/drivers/iio/dac/ad3552r.h
index 768fa264d39e9e6d517aeb4098382e072f153543..69ce96f132cdb353d2f140939c534586cb791aee 100644
--- a/drivers/iio/dac/ad3552r.h
+++ b/drivers/iio/dac/ad3552r.h
@@ -113,6 +113,8 @@
 #define AD3552R_REG_ADDR_INPUT_PAGE_MASK_24B		0x44
 #define AD3552R_REG_ADDR_SW_LDAC_24B			0x45
 #define AD3552R_REG_ADDR_CH_INPUT_24B(ch)		(0x4B - (1 - (ch)) * 3)
+#define AD3551R_REG_ADDR_MAX				0x46
+#define AD3552R_REG_ADDR_MAX				0x49
 
 #define AD3552R_MAX_CH					2
 #define AD3552R_MASK_CH(ch)				BIT(ch)

---
base-commit: 6f9141cdd726e82d209b5fc6d6b5ea32ace339f1
change-id: 20250319-wip-bl-ad3552r-fixes-4fbbe9dd1d2b

Best regards,
-- 
Angelo Dureghello <adureghello@baylibre.com>

Re: [PATCH] iio: dac: ad3552r-hs: add debugfs reg access

[Nuno Sá]

On Wed, 2025-03-19 at 12:02 +0100, Angelo Dureghello wrote:
> From: Angelo Dureghello <adureghello@baylibre.com>
> 
> Add debugfs register access.
> 
> Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
> ---

Minor nit you might consider to change if a v2 is needed for some reason...

Reviewed-by: Nuno Sá <nuno.sa@analog.com>

>  drivers/iio/dac/ad3552r-hs.c | 31 +++++++++++++++++++++++++++++++
>  drivers/iio/dac/ad3552r.h    |  2 ++
>  2 files changed, 33 insertions(+)
> 
> diff --git a/drivers/iio/dac/ad3552r-hs.c b/drivers/iio/dac/ad3552r-hs.c
> index
> cd8dabb60c5548780f0fce5d1b68c494cd71321d..7bb6d8817a545f16de9432526ae28787af1a
> 0146 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>
> @@ -56,6 +57,15 @@ struct ad3552r_hs_state {
>  	u32 config_d;
>  };
>  
> +static int ad3552r_hs_get_reg_length(unsigned int reg)
> +{
> +	/*
> +	 * There is no 3 or 4 bytes r/w len possible in HDL, so keeping 2
> +	 * also for the 24bit area.
> +	 */
> +	return (reg > AD3552R_SECONDARY_REGION_START) ? 2 : 1;
> +}
> +

I wonder about the added value of the above. Since it's really only used once, I
would do it inline