[PATCH v4 0/9] add support for Software mode on AD7606's iio backend driver

[PATCH v4 0/9] add support for Software mode on AD7606's iio backend driver

[Angelo Dureghello]

The previous series added iio_backend mode, but the configuration for this
mode was only possible through GPIOs (Hardware mode). Here, we add support
for configuring the chip using its registers (Software mode).

The bus access is based on Angelo's ad3552 implementation, that is we have
a particular compatible for the backend (here axi-adc) version supporting
the ad7606's register writing, and the ad7606 is defined as a child node
of the backend in the devicetree. Small changes are added to make the code
a bit more straightforward to understand, and more compact.

Signed-off-by: Guillaume Stols <gstols@baylibre.com>
Co-developed-by: Angelo Dureghello <adureghello@baylibre.com>
Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
Changes in v4:
- some spaces / tabs fixes,
- fix child nodes creation as done for dac,
- change usleep_range into flseep,
- use just a u32 as a value in bus access functions,
- protect bus access from concurrent access,
- Link to v3: https://lore.kernel.org/r/20250129-wip-bl-ad7606_add_backend_sw_mode-v3-0-c3aec77c0ab7@baylibre.com

Changes in v3:
- add some fixes found while testing,
- general commit meessages fixes,
- codying style fixes,
- dt-bindings: add some properties as requirted,
- use iio_device_claim_direct_mode (and release),
- rename bus read/write functions with "bus" as done for ad3552r.

Changes in v2:
- Improved descriptions.
- dt-bindings: improved descriptions, added exemple and additional
  property for the custom IP.
- Reworked some macro commits to avoid changing order and associated
  diff artifacts.
- Various cleanups and formatting fixes.
- Link to v1: https://lore.kernel.org/r/20241121-ad7606_add_iio_backend_software_mode-v1-0-8a693a5e3fa9@baylibre.com

---
Angelo Dureghello (3):
      iio: adc: adi-axi-adc: add struct axi_adc_info
      iio: adc: adi-axi-adc: add platform children support
      iio: adc: ad7606: protect register access

Guillaume Stols (6):
      dt-bindings: iio: dac: adi-axi-adc: add ad7606 variant
      iio: adc: ad7606: move the software mode configuration
      iio: adc: ad7606: move software functions into common file
      iio: adc: adi-axi-adc: add support for AD7606 register writing
      iio: adc: ad7606: change channel macros parameters
      iio: adc: ad7606: add support for writing registers when using backend

 .../devicetree/bindings/iio/adc/adi,axi-adc.yaml   |  70 +++++++-
 drivers/iio/adc/ad7606.c                           | 159 +++++++++++++++++--
 drivers/iio/adc/ad7606.h                           | 103 ++++++++----
 drivers/iio/adc/ad7606_bus_iface.h                 |  16 ++
 drivers/iio/adc/ad7606_par.c                       |  52 +++++-
 drivers/iio/adc/ad7606_spi.c                       | 137 +---------------
 drivers/iio/adc/adi-axi-adc.c                      | 176 +++++++++++++++++++--
 7 files changed, 516 insertions(+), 197 deletions(-)
---
base-commit: 4692f10bec7459a0baa95bdfa66a4ea740ec9e0a
change-id: 20250129-wip-bl-ad7606_add_backend_sw_mode-dd22a50663f3

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

[PATCH v4 1/9] dt-bindings: iio: dac: adi-axi-adc: add ad7606 variant

[Angelo Dureghello]

From: Guillaume Stols <gstols@baylibre.com>

A new compatible is added to reflect the specialized version of the HDL.
We use the parallel interface to write the ADC's registers, and
accessing this interface requires to use ADI_AXI_REG_CONFIG_RD,
ADI_AXI_REG_CONFIG_WR and ADI_AXI_REG_CONFIG_CTRL in a custom fashion.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Guillaume Stols <gstols@baylibre.com>
Co-developed-by: Angelo Dureghello <adureghello@baylibre.com>
Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
 .../devicetree/bindings/iio/adc/adi,axi-adc.yaml   | 70 +++++++++++++++++++++-
 1 file changed, 69 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.yaml b/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.yaml
index e1f450b80db2..4fa82dcf6fc9 100644
--- a/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.yaml
+++ b/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.yaml
@@ -17,13 +17,23 @@ description: |
   interface for the actual ADC, while this IP core will interface
   to the data-lines of the ADC and handle the streaming of data into
   memory via DMA.
+  In some cases, the AXI ADC interface is used to perform specialized
+  operation to a particular ADC, e.g access the physical bus through
+  specific registers to write ADC registers.
+  In this case, we use a different compatible which indicates the target
+  IP core's name.
+  The following IP is currently supported:
+    - AXI AD7606x: specialized version of the IP core for all the chips from
+      the ad7606 family.
 
   https://wiki.analog.com/resources/fpga/docs/axi_adc_ip
+  http://analogdevicesinc.github.io/hdl/library/axi_ad7606x/index.html
 
 properties:
   compatible:
     enum:
       - adi,axi-adc-10.0.a
+      - adi,axi-ad7606x
 
   reg:
     maxItems: 1
@@ -47,17 +57,48 @@ properties:
   '#io-backend-cells':
     const: 0
 
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+patternProperties:
+  "^adc@[0-9a-f]+$":
+    type: object
+    properties:
+      reg:
+        maxItems: 1
+    additionalProperties: true
+    required:
+      - compatible
+      - reg
+
 required:
   - compatible
   - dmas
   - reg
   - clocks
 
+allOf:
+  - if:
+      properties:
+        compatible:
+          not:
+            contains:
+              const: adi,axi-ad7606x
+    then:
+      properties:
+        '#address-cells': false
+        '#size-cells': false
+      patternProperties:
+        "^adc@[0-9a-f]+$": false
+
 additionalProperties: false
 
 examples:
   - |
-    axi-adc@44a00000 {
+    adc@44a00000 {
         compatible = "adi,axi-adc-10.0.a";
         reg = <0x44a00000 0x10000>;
         dmas = <&rx_dma 0>;
@@ -65,4 +106,31 @@ examples:
         clocks = <&axi_clk>;
         #io-backend-cells = <0>;
     };
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    parallel_bus_controller@44a00000 {
+        compatible = "adi,axi-ad7606x";
+        reg = <0x44a00000 0x10000>;
+        dmas = <&rx_dma 0>;
+        dma-names = "rx";
+        clocks = <&ext_clk>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        adc@0 {
+            compatible = "adi,ad7606b";
+            reg = <0>;
+            pwms = <&axi_pwm_gen 0 0>;
+            pwm-names = "convst1";
+            avcc-supply = <&adc_vref>;
+            vdrive-supply = <&vdd_supply>;
+            reset-gpios = <&gpio0 91 GPIO_ACTIVE_HIGH>;
+            standby-gpios = <&gpio0 90 GPIO_ACTIVE_LOW>;
+            adi,range-gpios = <&gpio0 89 GPIO_ACTIVE_HIGH>;
+            adi,oversampling-ratio-gpios = <&gpio0 88 GPIO_ACTIVE_HIGH
+                            &gpio0 87 GPIO_ACTIVE_HIGH
+                            &gpio0 86 GPIO_ACTIVE_HIGH>;
+            io-backends = <&parallel_bus_controller>;
+        };
+    };
 ...

-- 
2.47.0

[PATCH v4 2/9] iio: adc: ad7606: move the software mode configuration

[Angelo Dureghello]

From: Guillaume Stols <gstols@baylibre.com>

This is a preparation for the intoduction of the sofware functions in
the iio backend version of the driver.
The software mode configuration must be executed once the channels are
configured, and the number of channels is known. This is not the case
before iio-backend's configuration is called, and iio backend version of
the driver does not have a timestamp channel.
Also the sw_mode_config callback is configured during the iio-backend
configuration.
For clarity purpose, I moved the entire block instead of just the
concerned function calls.

Signed-off-by: Guillaume Stols <gstols@baylibre.com>
---
 drivers/iio/adc/ad7606.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c
index d39354afd539..376c808df11c 100644
--- a/drivers/iio/adc/ad7606.c
+++ b/drivers/iio/adc/ad7606.c
@@ -1246,17 +1246,6 @@ int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
 			return -ERESTARTSYS;
 	}
 
-	st->write_scale = ad7606_write_scale_hw;
-	st->write_os = ad7606_write_os_hw;
-
-	ret = ad7606_sw_mode_setup(indio_dev);
-	if (ret)
-		return ret;
-
-	ret = ad7606_chan_scales_setup(indio_dev);
-	if (ret)
-		return ret;
-
 	/* If convst pin is not defined, setup PWM. */
 	if (!st->gpio_convst) {
 		st->cnvst_pwm = devm_pwm_get(dev, NULL);
@@ -1334,6 +1323,17 @@ int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
 			return ret;
 	}
 
+	st->write_scale = ad7606_write_scale_hw;
+	st->write_os = ad7606_write_os_hw;
+
+	ret = ad7606_sw_mode_setup(indio_dev);
+	if (ret)
+		return ret;
+
+	ret = ad7606_chan_scales_setup(indio_dev);
+	if (ret)
+		return ret;
+
 	return devm_iio_device_register(dev, indio_dev);
 }
 EXPORT_SYMBOL_NS_GPL(ad7606_probe, "IIO_AD7606");

-- 
2.47.0

[PATCH v4 3/9] iio: adc: ad7606: move software functions into common file

[Angelo Dureghello]

From: Guillaume Stols <gstols@baylibre.com>

Since the register are always the same, whatever bus is used, moving the
software functions into the main file avoids the code to be duplicated
in both SPI and parallel version of the driver.

Signed-off-by: Guillaume Stols <gstols@baylibre.com>
Co-developed-by: Angelo Dureghello <adureghello@baylibre.com>
Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
 drivers/iio/adc/ad7606.c     | 133 ++++++++++++++++++++++++++++++++++++++---
 drivers/iio/adc/ad7606.h     |  37 ++++++++++--
 drivers/iio/adc/ad7606_spi.c | 137 +------------------------------------------
 3 files changed, 158 insertions(+), 149 deletions(-)

diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c
index 376c808df11c..7985570ed152 100644
--- a/drivers/iio/adc/ad7606.c
+++ b/drivers/iio/adc/ad7606.c
@@ -85,6 +85,10 @@ static const unsigned int ad7606_oversampling_avail[7] = {
 	1, 2, 4, 8, 16, 32, 64,
 };
 
+static const unsigned int ad7606b_oversampling_avail[9] = {
+	1, 2, 4, 8, 16, 32, 64, 128, 256,
+};
+
 static const unsigned int ad7616_oversampling_avail[8] = {
 	1, 2, 4, 8, 16, 32, 64, 128,
 };
@@ -187,6 +191,8 @@ static int ad7608_chan_scale_setup(struct iio_dev *indio_dev,
 				   struct iio_chan_spec *chan, int ch);
 static int ad7609_chan_scale_setup(struct iio_dev *indio_dev,
 				   struct iio_chan_spec *chan, int ch);
+static int ad7616_sw_mode_setup(struct iio_dev *indio_dev);
+static int ad7606b_sw_mode_setup(struct iio_dev *indio_dev);
 
 const struct ad7606_chip_info ad7605_4_info = {
 	.channels = ad7605_channels,
@@ -239,6 +245,7 @@ const struct ad7606_chip_info ad7606b_info = {
 	.oversampling_avail = ad7606_oversampling_avail,
 	.oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
 	.scale_setup_cb = ad7606_16bit_chan_scale_setup,
+	.sw_setup_cb = ad7606b_sw_mode_setup,
 };
 EXPORT_SYMBOL_NS_GPL(ad7606b_info, "IIO_AD7606");
 
@@ -250,6 +257,7 @@ const struct ad7606_chip_info ad7606c_16_info = {
 	.oversampling_avail = ad7606_oversampling_avail,
 	.oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
 	.scale_setup_cb = ad7606c_16bit_chan_scale_setup,
+	.sw_setup_cb = ad7606b_sw_mode_setup,
 };
 EXPORT_SYMBOL_NS_GPL(ad7606c_16_info, "IIO_AD7606");
 
@@ -294,6 +302,7 @@ const struct ad7606_chip_info ad7606c_18_info = {
 	.oversampling_avail = ad7606_oversampling_avail,
 	.oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
 	.scale_setup_cb = ad7606c_18bit_chan_scale_setup,
+	.sw_setup_cb = ad7606b_sw_mode_setup,
 };
 EXPORT_SYMBOL_NS_GPL(ad7606c_18_info, "IIO_AD7606");
 
@@ -307,6 +316,7 @@ const struct ad7606_chip_info ad7616_info = {
 	.oversampling_num = ARRAY_SIZE(ad7616_oversampling_avail),
 	.os_req_reset = true,
 	.scale_setup_cb = ad7606_16bit_chan_scale_setup,
+	.sw_setup_cb = ad7616_sw_mode_setup,
 };
 EXPORT_SYMBOL_NS_GPL(ad7616_info, "IIO_AD7606");
 
@@ -1138,16 +1148,118 @@ static const struct iio_trigger_ops ad7606_trigger_ops = {
 	.validate_device = iio_trigger_validate_own_device,
 };
 
-static int ad7606_sw_mode_setup(struct iio_dev *indio_dev)
+static int ad7606_write_mask(struct ad7606_state *st, unsigned int addr,
+			     unsigned long mask, unsigned int val)
+{
+	int readval;
+
+	readval = st->bops->reg_read(st, addr);
+	if (readval < 0)
+		return readval;
+
+	readval &= ~mask;
+	readval |= val;
+
+	return st->bops->reg_write(st, addr, readval);
+}
+
+static int ad7616_write_scale_sw(struct iio_dev *indio_dev, int ch, int val)
 {
 	struct ad7606_state *st = iio_priv(indio_dev);
+	unsigned int ch_addr, mode, ch_index;
 
-	st->sw_mode_en = st->bops->sw_mode_config &&
-			 device_property_present(st->dev, "adi,sw-mode");
-	if (!st->sw_mode_en)
-		return 0;
+	/*
+	 * Ad7616 has 16 channels divided in group A and group B.
+	 * The range of channels from A are stored in registers with address 4
+	 * while channels from B are stored in register with address 6.
+	 * The last bit from channels determines if it is from group A or B
+	 * because the order of channels in iio is 0A, 0B, 1A, 1B...
+	 */
+	ch_index = ch >> 1;
+
+	ch_addr = AD7616_RANGE_CH_ADDR(ch_index);
+
+	if ((ch & 0x1) == 0) /* channel A */
+		ch_addr += AD7616_RANGE_CH_A_ADDR_OFF;
+	else	/* channel B */
+		ch_addr += AD7616_RANGE_CH_B_ADDR_OFF;
+
+	/* 0b01 for 2.5v, 0b10 for 5v and 0b11 for 10v */
+	mode = AD7616_RANGE_CH_MODE(ch_index, ((val + 1) & 0b11));
 
-	indio_dev->info = &ad7606_info_sw_mode;
+	return ad7606_write_mask(st, ch_addr, AD7616_RANGE_CH_MSK(ch_index),
+				 mode);
+}
+
+static int ad7616_write_os_sw(struct iio_dev *indio_dev, int val)
+{
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	return ad7606_write_mask(st, AD7616_CONFIGURATION_REGISTER,
+				 AD7616_OS_MASK, val << 2);
+}
+
+static int ad7606_write_scale_sw(struct iio_dev *indio_dev, int ch, int val)
+{
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	return ad7606_write_mask(st, AD7606_RANGE_CH_ADDR(ch),
+				 AD7606_RANGE_CH_MSK(ch),
+				 AD7606_RANGE_CH_MODE(ch, val));
+}
+
+static int ad7606_write_os_sw(struct iio_dev *indio_dev, int val)
+{
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	return st->bops->reg_write(st, AD7606_OS_MODE, val);
+}
+
+static int ad7616_sw_mode_setup(struct iio_dev *indio_dev)
+{
+	struct ad7606_state *st = iio_priv(indio_dev);
+	int ret;
+
+	/*
+	 * Scale can be configured individually for each channel
+	 * in software mode.
+	 */
+
+	st->write_scale = ad7616_write_scale_sw;
+	st->write_os = &ad7616_write_os_sw;
+
+	ret = st->bops->sw_mode_config(indio_dev);
+	if (ret)
+		return ret;
+
+	/* Activate Burst mode and SEQEN MODE */
+	return ad7606_write_mask(st, AD7616_CONFIGURATION_REGISTER,
+				 AD7616_BURST_MODE | AD7616_SEQEN_MODE,
+				 AD7616_BURST_MODE | AD7616_SEQEN_MODE);
+}
+
+static int ad7606b_sw_mode_setup(struct iio_dev *indio_dev)
+{
+	struct ad7606_state *st = iio_priv(indio_dev);
+	DECLARE_BITMAP(os, 3);
+
+	bitmap_fill(os, 3);
+	/*
+	 * Software mode is enabled when all three oversampling
+	 * pins are set to high. If oversampling gpios are defined
+	 * in the device tree, then they need to be set to high,
+	 * otherwise, they must be hardwired to VDD
+	 */
+	if (st->gpio_os) {
+		gpiod_set_array_value(st->gpio_os->ndescs, st->gpio_os->desc,
+				      st->gpio_os->info, os);
+	}
+	/* OS of 128 and 256 are available only in software mode */
+	st->oversampling_avail = ad7606b_oversampling_avail;
+	st->num_os_ratios = ARRAY_SIZE(ad7606b_oversampling_avail);
+
+	st->write_scale = ad7606_write_scale_sw;
+	st->write_os = &ad7606_write_os_sw;
 
 	return st->bops->sw_mode_config(indio_dev);
 }
@@ -1326,9 +1438,12 @@ int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
 	st->write_scale = ad7606_write_scale_hw;
 	st->write_os = ad7606_write_os_hw;
 
-	ret = ad7606_sw_mode_setup(indio_dev);
-	if (ret)
-		return ret;
+	st->sw_mode_en = st->chip_info->sw_setup_cb &&
+			 device_property_present(st->dev, "adi,sw-mode");
+	if (st->sw_mode_en) {
+		indio_dev->info = &ad7606_info_sw_mode;
+		st->chip_info->sw_setup_cb(indio_dev);
+	}
 
 	ret = ad7606_chan_scales_setup(indio_dev);
 	if (ret)
diff --git a/drivers/iio/adc/ad7606.h b/drivers/iio/adc/ad7606.h
index 8778ffe515b3..7a044b499cfe 100644
--- a/drivers/iio/adc/ad7606.h
+++ b/drivers/iio/adc/ad7606.h
@@ -10,6 +10,36 @@
 
 #define AD760X_MAX_CHANNELS	16
 
+#define AD7616_CONFIGURATION_REGISTER	0x02
+#define AD7616_OS_MASK			GENMASK(4, 2)
+#define AD7616_BURST_MODE		BIT(6)
+#define AD7616_SEQEN_MODE		BIT(5)
+#define AD7616_RANGE_CH_A_ADDR_OFF	0x04
+#define AD7616_RANGE_CH_B_ADDR_OFF	0x06
+/*
+ * Range of channels from a group are stored in 2 registers.
+ * 0, 1, 2, 3 in a register followed by 4, 5, 6, 7 in second register.
+ * For channels from second group(8-15) the order is the same, only with
+ * an offset of 2 for register address.
+ */
+#define AD7616_RANGE_CH_ADDR(ch)	((ch) >> 2)
+/* The range of the channel is stored in 2 bits */
+#define AD7616_RANGE_CH_MSK(ch)		(0b11 << (((ch) & 0b11) * 2))
+#define AD7616_RANGE_CH_MODE(ch, mode)	((mode) << ((((ch) & 0b11)) * 2))
+
+#define AD7606_CONFIGURATION_REGISTER	0x02
+#define AD7606_SINGLE_DOUT		0x00
+
+/*
+ * Range for AD7606B channels are stored in registers starting with address 0x3.
+ * Each register stores range for 2 channels(4 bits per channel).
+ */
+#define AD7606_RANGE_CH_MSK(ch)		(GENMASK(3, 0) << (4 * ((ch) & 0x1)))
+#define AD7606_RANGE_CH_MODE(ch, mode)	\
+	((GENMASK(3, 0) & (mode)) << (4 * ((ch) & 0x1)))
+#define AD7606_RANGE_CH_ADDR(ch)	(0x03 + ((ch) >> 1))
+#define AD7606_OS_MODE			0x08
+
 #define AD760X_CHANNEL(num, mask_sep, mask_type, mask_all, bits) {	\
 		.type = IIO_VOLTAGE,				\
 		.indexed = 1,					\
@@ -71,6 +101,7 @@ struct ad7606_state;
 
 typedef int (*ad7606_scale_setup_cb_t)(struct iio_dev *indio_dev,
 				       struct iio_chan_spec *chan, int ch);
+typedef int (*ad7606_sw_setup_cb_t)(struct iio_dev *indio_dev);
 
 /**
  * struct ad7606_chip_info - chip specific information
@@ -80,6 +111,7 @@ typedef int (*ad7606_scale_setup_cb_t)(struct iio_dev *indio_dev,
  * @num_channels:	number of channels
  * @num_adc_channels	the number of channels the ADC actually inputs.
  * @scale_setup_cb:	callback to setup the scales for each channel
+ * @sw_setup_cb:	callback to setup the software mode if available.
  * @oversampling_avail	pointer to the array which stores the available
  *			oversampling ratios.
  * @oversampling_num	number of elements stored in oversampling_avail array
@@ -94,6 +126,7 @@ struct ad7606_chip_info {
 	unsigned int			num_adc_channels;
 	unsigned int			num_channels;
 	ad7606_scale_setup_cb_t		scale_setup_cb;
+	ad7606_sw_setup_cb_t		sw_setup_cb;
 	const unsigned int		*oversampling_avail;
 	unsigned int			oversampling_num;
 	bool				os_req_reset;
@@ -206,10 +239,6 @@ struct ad7606_bus_ops {
 	int (*reg_write)(struct ad7606_state *st,
 				unsigned int addr,
 				unsigned int val);
-	int (*write_mask)(struct ad7606_state *st,
-				 unsigned int addr,
-				 unsigned long mask,
-				 unsigned int val);
 	int (*update_scan_mode)(struct iio_dev *indio_dev, const unsigned long *scan_mask);
 	u16 (*rd_wr_cmd)(int addr, char isWriteOp);
 };
diff --git a/drivers/iio/adc/ad7606_spi.c b/drivers/iio/adc/ad7606_spi.c
index e2c147525706..885bf0b68e77 100644
--- a/drivers/iio/adc/ad7606_spi.c
+++ b/drivers/iio/adc/ad7606_spi.c
@@ -15,36 +15,6 @@
 
 #define MAX_SPI_FREQ_HZ		23500000	/* VDRIVE above 4.75 V */
 
-#define AD7616_CONFIGURATION_REGISTER	0x02
-#define AD7616_OS_MASK			GENMASK(4, 2)
-#define AD7616_BURST_MODE		BIT(6)
-#define AD7616_SEQEN_MODE		BIT(5)
-#define AD7616_RANGE_CH_A_ADDR_OFF	0x04
-#define AD7616_RANGE_CH_B_ADDR_OFF	0x06
-/*
- * Range of channels from a group are stored in 2 registers.
- * 0, 1, 2, 3 in a register followed by 4, 5, 6, 7 in second register.
- * For channels from second group(8-15) the order is the same, only with
- * an offset of 2 for register address.
- */
-#define AD7616_RANGE_CH_ADDR(ch)	((ch) >> 2)
-/* The range of the channel is stored in 2 bits */
-#define AD7616_RANGE_CH_MSK(ch)		(0b11 << (((ch) & 0b11) * 2))
-#define AD7616_RANGE_CH_MODE(ch, mode)	((mode) << ((((ch) & 0b11)) * 2))
-
-#define AD7606_CONFIGURATION_REGISTER	0x02
-#define AD7606_SINGLE_DOUT		0x00
-
-/*
- * Range for AD7606B channels are stored in registers starting with address 0x3.
- * Each register stores range for 2 channels(4 bits per channel).
- */
-#define AD7606_RANGE_CH_MSK(ch)		(GENMASK(3, 0) << (4 * ((ch) & 0x1)))
-#define AD7606_RANGE_CH_MODE(ch, mode)	\
-	((GENMASK(3, 0) & mode) << (4 * ((ch) & 0x1)))
-#define AD7606_RANGE_CH_ADDR(ch)	(0x03 + ((ch) >> 1))
-#define AD7606_OS_MODE			0x08
-
 static const struct iio_chan_spec ad7616_sw_channels[] = {
 	IIO_CHAN_SOFT_TIMESTAMP(16),
 	AD7616_CHANNEL(0),
@@ -89,10 +59,6 @@ static const struct iio_chan_spec ad7606c_18_sw_channels[] = {
 	AD7606_SW_CHANNEL(7, 18),
 };
 
-static const unsigned int ad7606B_oversampling_avail[9] = {
-	1, 2, 4, 8, 16, 32, 64, 128, 256
-};
-
 static u16 ad7616_spi_rd_wr_cmd(int addr, char isWriteOp)
 {
 	/*
@@ -194,118 +160,20 @@ static int ad7606_spi_reg_write(struct ad7606_state *st,
 	return spi_write(spi, &st->d16[0], sizeof(st->d16[0]));
 }
 
-static int ad7606_spi_write_mask(struct ad7606_state *st,
-				 unsigned int addr,
-				 unsigned long mask,
-				 unsigned int val)
-{
-	int readval;
-
-	readval = st->bops->reg_read(st, addr);
-	if (readval < 0)
-		return readval;
-
-	readval &= ~mask;
-	readval |= val;
-
-	return st->bops->reg_write(st, addr, readval);
-}
-
-static int ad7616_write_scale_sw(struct iio_dev *indio_dev, int ch, int val)
-{
-	struct ad7606_state *st = iio_priv(indio_dev);
-	unsigned int ch_addr, mode, ch_index;
-
-
-	/*
-	 * Ad7616 has 16 channels divided in group A and group B.
-	 * The range of channels from A are stored in registers with address 4
-	 * while channels from B are stored in register with address 6.
-	 * The last bit from channels determines if it is from group A or B
-	 * because the order of channels in iio is 0A, 0B, 1A, 1B...
-	 */
-	ch_index = ch >> 1;
-
-	ch_addr = AD7616_RANGE_CH_ADDR(ch_index);
-
-	if ((ch & 0x1) == 0) /* channel A */
-		ch_addr += AD7616_RANGE_CH_A_ADDR_OFF;
-	else	/* channel B */
-		ch_addr += AD7616_RANGE_CH_B_ADDR_OFF;
-
-	/* 0b01 for 2.5v, 0b10 for 5v and 0b11 for 10v */
-	mode = AD7616_RANGE_CH_MODE(ch_index, ((val + 1) & 0b11));
-	return st->bops->write_mask(st, ch_addr, AD7616_RANGE_CH_MSK(ch_index),
-				     mode);
-}
-
-static int ad7616_write_os_sw(struct iio_dev *indio_dev, int val)
-{
-	struct ad7606_state *st = iio_priv(indio_dev);
-
-	return st->bops->write_mask(st, AD7616_CONFIGURATION_REGISTER,
-				     AD7616_OS_MASK, val << 2);
-}
-
-static int ad7606_write_scale_sw(struct iio_dev *indio_dev, int ch, int val)
-{
-	struct ad7606_state *st = iio_priv(indio_dev);
-
-	return ad7606_spi_write_mask(st,
-				     AD7606_RANGE_CH_ADDR(ch),
-				     AD7606_RANGE_CH_MSK(ch),
-				     AD7606_RANGE_CH_MODE(ch, val));
-}
-
-static int ad7606_write_os_sw(struct iio_dev *indio_dev, int val)
-{
-	struct ad7606_state *st = iio_priv(indio_dev);
-
-	return ad7606_spi_reg_write(st, AD7606_OS_MODE, val);
-}
-
 static int ad7616_sw_mode_config(struct iio_dev *indio_dev)
 {
-	struct ad7606_state *st = iio_priv(indio_dev);
-
 	/*
 	 * Scale can be configured individually for each channel
 	 * in software mode.
 	 */
 	indio_dev->channels = ad7616_sw_channels;
 
-	st->write_scale = ad7616_write_scale_sw;
-	st->write_os = &ad7616_write_os_sw;
-
-	/* Activate Burst mode and SEQEN MODE */
-	return st->bops->write_mask(st,
-			      AD7616_CONFIGURATION_REGISTER,
-			      AD7616_BURST_MODE | AD7616_SEQEN_MODE,
-			      AD7616_BURST_MODE | AD7616_SEQEN_MODE);
+	return 0;
 }
 
 static int ad7606B_sw_mode_config(struct iio_dev *indio_dev)
 {
 	struct ad7606_state *st = iio_priv(indio_dev);
-	DECLARE_BITMAP(os, 3);
-
-	bitmap_fill(os, 3);
-	/*
-	 * Software mode is enabled when all three oversampling
-	 * pins are set to high. If oversampling gpios are defined
-	 * in the device tree, then they need to be set to high,
-	 * otherwise, they must be hardwired to VDD
-	 */
-	if (st->gpio_os) {
-		gpiod_set_array_value(st->gpio_os->ndescs,
-				      st->gpio_os->desc, st->gpio_os->info, os);
-	}
-	/* OS of 128 and 256 are available only in software mode */
-	st->oversampling_avail = ad7606B_oversampling_avail;
-	st->num_os_ratios = ARRAY_SIZE(ad7606B_oversampling_avail);
-
-	st->write_scale = ad7606_write_scale_sw;
-	st->write_os = &ad7606_write_os_sw;
 
 	/* Configure device spi to output on a single channel */
 	st->bops->reg_write(st,
@@ -350,7 +218,6 @@ static const struct ad7606_bus_ops ad7616_spi_bops = {
 	.read_block = ad7606_spi_read_block,
 	.reg_read = ad7606_spi_reg_read,
 	.reg_write = ad7606_spi_reg_write,
-	.write_mask = ad7606_spi_write_mask,
 	.rd_wr_cmd = ad7616_spi_rd_wr_cmd,
 	.sw_mode_config = ad7616_sw_mode_config,
 };
@@ -359,7 +226,6 @@ static const struct ad7606_bus_ops ad7606b_spi_bops = {
 	.read_block = ad7606_spi_read_block,
 	.reg_read = ad7606_spi_reg_read,
 	.reg_write = ad7606_spi_reg_write,
-	.write_mask = ad7606_spi_write_mask,
 	.rd_wr_cmd = ad7606B_spi_rd_wr_cmd,
 	.sw_mode_config = ad7606B_sw_mode_config,
 };
@@ -368,7 +234,6 @@ static const struct ad7606_bus_ops ad7606c_18_spi_bops = {
 	.read_block = ad7606_spi_read_block18to32,
 	.reg_read = ad7606_spi_reg_read,
 	.reg_write = ad7606_spi_reg_write,
-	.write_mask = ad7606_spi_write_mask,
 	.rd_wr_cmd = ad7606B_spi_rd_wr_cmd,
 	.sw_mode_config = ad7606c_18_sw_mode_config,
 };

-- 
2.47.0

[PATCH v4 4/9] iio: adc: adi-axi-adc: add struct axi_adc_info

[Angelo Dureghello]

From: Angelo Dureghello <adureghello@baylibre.com>

Add struct axi_adc_info to allow different axi-adc compatibles that can
be added to this generic implementation.

Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
 drivers/iio/adc/adi-axi-adc.c | 30 +++++++++++++++++++++---------
 1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/drivers/iio/adc/adi-axi-adc.c b/drivers/iio/adc/adi-axi-adc.c
index c7357601f0f8..b38e8a27af94 100644
--- a/drivers/iio/adc/adi-axi-adc.c
+++ b/drivers/iio/adc/adi-axi-adc.c
@@ -80,7 +80,16 @@
 	 ADI_AXI_REG_CHAN_CTRL_FMT_EN |		\
 	 ADI_AXI_REG_CHAN_CTRL_ENABLE)
 
+struct axi_adc_info {
+	unsigned int version;
+	const struct iio_backend_info *backend_info;
+	bool has_child_nodes;
+	const void *pdata;
+	unsigned int pdata_sz;
+};
+
 struct adi_axi_adc_state {
+	const struct axi_adc_info *info;
 	struct regmap *regmap;
 	struct device *dev;
 	/* lock to protect multiple accesses to the device registers */
@@ -348,7 +357,6 @@ static const struct iio_backend_info adi_axi_adc_generic = {
 
 static int adi_axi_adc_probe(struct platform_device *pdev)
 {
-	const unsigned int *expected_ver;
 	struct adi_axi_adc_state *st;
 	void __iomem *base;
 	unsigned int ver;
@@ -370,8 +378,8 @@ static int adi_axi_adc_probe(struct platform_device *pdev)
 		return dev_err_probe(&pdev->dev, PTR_ERR(st->regmap),
 				     "failed to init register map\n");
 
-	expected_ver = device_get_match_data(&pdev->dev);
-	if (!expected_ver)
+	st->info = device_get_match_data(&pdev->dev);
+	if (!st->info)
 		return -ENODEV;
 
 	clk = devm_clk_get_enabled(&pdev->dev, NULL);
@@ -391,12 +399,13 @@ static int adi_axi_adc_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	if (ADI_AXI_PCORE_VER_MAJOR(ver) != ADI_AXI_PCORE_VER_MAJOR(*expected_ver)) {
+	if (ADI_AXI_PCORE_VER_MAJOR(ver) !=
+	    ADI_AXI_PCORE_VER_MAJOR(st->info->version)) {
 		dev_err(&pdev->dev,
 			"Major version mismatch. Expected %d.%.2d.%c, Reported %d.%.2d.%c\n",
-			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(st->info->version),
+			ADI_AXI_PCORE_VER_MINOR(st->info->version),
+			ADI_AXI_PCORE_VER_PATCH(st->info->version),
 			ADI_AXI_PCORE_VER_MAJOR(ver),
 			ADI_AXI_PCORE_VER_MINOR(ver),
 			ADI_AXI_PCORE_VER_PATCH(ver));
@@ -416,11 +425,14 @@ 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');
+static const struct axi_adc_info adc_generic = {
+	.version = ADI_AXI_PCORE_VER(10, 0, 'a'),
+	.backend_info = &adi_axi_adc_generic,
+};
 
 /* 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 },
+	{ .compatible = "adi,axi-adc-10.0.a", .data = &adc_generic },
 	{ /* end of list */ }
 };
 MODULE_DEVICE_TABLE(of, adi_axi_adc_of_match);

-- 
2.47.0

[PATCH v4 5/9] iio: adc: adi-axi-adc: add platform children support

[Angelo Dureghello]

From: Angelo Dureghello <adureghello@baylibre.com>

This is a preparation for the next commit adding support for register
read and write functions on AD7606.
Since sometimes a bus will be used, it has been agreed during ad3552's
driver implementation that the device's driver bus is the backend, whose
device node will be a child node.
To provide the special callbacks for setting the register, axi-adc needs
to pass them to the child device's driver through platform data.

Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
 drivers/iio/adc/ad7606_bus_iface.h | 16 ++++++++++
 drivers/iio/adc/adi-axi-adc.c      | 65 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 81 insertions(+)

diff --git a/drivers/iio/adc/ad7606_bus_iface.h b/drivers/iio/adc/ad7606_bus_iface.h
new file mode 100644
index 000000000000..f2c979a9b7f3
--- /dev/null
+++ b/drivers/iio/adc/ad7606_bus_iface.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2010-2024 Analog Devices Inc.
+ * Copyright (c) 2025 Baylibre, SAS
+ */
+#ifndef __LINUX_PLATFORM_DATA_AD7606_H__
+#define __LINUX_PLATFORM_DATA_AD7606_H__
+
+struct iio_backend;
+
+struct ad7606_platform_data {
+	int (*bus_reg_read)(struct iio_backend *back, u32 reg, u32 *val);
+	int (*bus_reg_write)(struct iio_backend *back, u32 reg, u32 val);
+};
+
+#endif /* __LINUX_PLATFORM_DATA_AD7606_H__ */
diff --git a/drivers/iio/adc/adi-axi-adc.c b/drivers/iio/adc/adi-axi-adc.c
index b38e8a27af94..3e1a997ace76 100644
--- a/drivers/iio/adc/adi-axi-adc.c
+++ b/drivers/iio/adc/adi-axi-adc.c
@@ -334,6 +334,36 @@ static const struct regmap_config axi_adc_regmap_config = {
 	.reg_stride = 4,
 };
 
+static void axi_adc_child_remove(void *data)
+{
+	platform_device_unregister(data);
+}
+
+static int axi_adc_create_platform_device(struct adi_axi_adc_state *st,
+					  struct fwnode_handle *child)
+{
+	struct platform_device_info pi = {
+	    .parent = st->dev,
+	    .name = fwnode_get_name(child),
+	    .id = PLATFORM_DEVID_AUTO,
+	    .fwnode = child,
+	    .data = st->info->pdata,
+	    .size_data = st->info->pdata_sz,
+	};
+	struct platform_device *pdev;
+	int ret;
+
+	pdev = platform_device_register_full(&pi);
+	if (IS_ERR(pdev))
+		return PTR_ERR(pdev);
+
+	ret = devm_add_action_or_reset(st->dev, axi_adc_child_remove, pdev);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
 static const struct iio_backend_ops adi_axi_adc_ops = {
 	.enable = axi_adc_enable,
 	.disable = axi_adc_disable,
@@ -417,6 +447,28 @@ static int adi_axi_adc_probe(struct platform_device *pdev)
 		return dev_err_probe(&pdev->dev, ret,
 				     "failed to register iio backend\n");
 
+	device_for_each_child_node_scoped(&pdev->dev, child) {
+		int val;
+
+		if (!st->info->has_child_nodes)
+			return dev_err_probe(&pdev->dev, -EINVAL,
+					     "invalid fdt axi-dac compatible.");
+
+		/* Processing only reg 0 node */
+		ret = fwnode_property_read_u32(child, "reg", &val);
+		if (ret)
+			return dev_err_probe(&pdev->dev, ret,
+					     "invalid reg property.");
+		if (val != 0)
+			return dev_err_probe(&pdev->dev, -EINVAL,
+					     "invalid node address.");
+
+		ret = axi_adc_create_platform_device(st, child);
+		if (ret)
+			return dev_err_probe(&pdev->dev, -EINVAL,
+					     "cannot create device.");
+	}
+
 	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),
@@ -430,6 +482,19 @@ static const struct axi_adc_info adc_generic = {
 	.backend_info = &adi_axi_adc_generic,
 };
 
+static const struct ad7606_platform_data ad7606_pdata = {
+	.bus_reg_read = ad7606_bus_reg_read,
+	.bus_reg_write = ad7606_bus_reg_write,
+};
+
+static const struct axi_adc_info adc_ad7606 = {
+	.version = ADI_AXI_PCORE_VER(10, 0, 'a'),
+	.backend_info = &adi_axi_adc_generic,
+	.pdata = &ad7606_pdata,
+	.pdata_sz = sizeof(ad7606_pdata),
+	.has_child_nodes = true,
+};
+
 /* 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 = &adc_generic },

-- 
2.47.0

[PATCH v4 6/9] iio: adc: adi-axi-adc: add support for AD7606 register writing

[Angelo Dureghello]

From: Guillaume Stols <gstols@baylibre.com>

Since we must access the bus parallel bus using a custom procedure,
let's add a specialized compatible, and define specialized callbacks for
writing the registers using the parallel interface.

Signed-off-by: Guillaume Stols <gstols@baylibre.com>
Co-developed-by: Angelo Dureghello <adureghello@baylibre.com>
Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
 drivers/iio/adc/adi-axi-adc.c | 81 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)

diff --git a/drivers/iio/adc/adi-axi-adc.c b/drivers/iio/adc/adi-axi-adc.c
index 3e1a997ace76..225ea0497ba9 100644
--- a/drivers/iio/adc/adi-axi-adc.c
+++ b/drivers/iio/adc/adi-axi-adc.c
@@ -27,6 +27,7 @@
 #include <linux/iio/buffer.h>
 #include <linux/iio/iio.h>
 
+#include "ad7606_bus_iface.h"
 /*
  * Register definitions:
  *   https://wiki.analog.com/resources/fpga/docs/axi_adc_ip#register_map
@@ -73,6 +74,12 @@
 #define ADI_AXI_ADC_REG_DELAY(l)		(0x0800 + (l) * 0x4)
 #define   AXI_ADC_DELAY_CTRL_MASK		GENMASK(4, 0)
 
+#define ADI_AXI_REG_CONFIG_WR			0x0080
+#define ADI_AXI_REG_CONFIG_RD			0x0084
+#define ADI_AXI_REG_CONFIG_CTRL			0x008c
+#define   ADI_AXI_REG_CONFIG_CTRL_READ		0x03
+#define   ADI_AXI_REG_CONFIG_CTRL_WRITE		0x01
+
 #define ADI_AXI_ADC_MAX_IO_NUM_LANES		15
 
 #define ADI_AXI_REG_CHAN_CTRL_DEFAULTS		\
@@ -80,6 +87,10 @@
 	 ADI_AXI_REG_CHAN_CTRL_FMT_EN |		\
 	 ADI_AXI_REG_CHAN_CTRL_ENABLE)
 
+#define ADI_AXI_REG_READ_BIT			0x8000
+#define ADI_AXI_REG_ADDRESS_MASK		0xff00
+#define ADI_AXI_REG_VALUE_MASK			0x00ff
+
 struct axi_adc_info {
 	unsigned int version;
 	const struct iio_backend_info *backend_info;
@@ -311,6 +322,75 @@ static struct iio_buffer *axi_adc_request_buffer(struct iio_backend *back,
 	return iio_dmaengine_buffer_setup(st->dev, indio_dev, dma_name);
 }
 
+static int axi_adc_raw_write(struct iio_backend *back, u32 val)
+{
+	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
+
+	regmap_write(st->regmap, ADI_AXI_REG_CONFIG_WR, val);
+	regmap_write(st->regmap, ADI_AXI_REG_CONFIG_CTRL,
+		     ADI_AXI_REG_CONFIG_CTRL_WRITE);
+	fsleep(100);
+	regmap_write(st->regmap, ADI_AXI_REG_CONFIG_CTRL, 0x00);
+	fsleep(100);
+
+	return 0;
+}
+
+static int axi_adc_raw_read(struct iio_backend *back, u32 *val)
+{
+	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
+
+	regmap_write(st->regmap, ADI_AXI_REG_CONFIG_CTRL,
+		     ADI_AXI_REG_CONFIG_CTRL_READ);
+	fsleep(100);
+	regmap_read(st->regmap, ADI_AXI_REG_CONFIG_RD, val);
+	regmap_write(st->regmap, ADI_AXI_REG_CONFIG_CTRL, 0x00);
+	fsleep(100);
+
+	return 0;
+}
+
+static int ad7606_bus_reg_read(struct iio_backend *back, u32 reg, u32 *val)
+{
+	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
+	int addr;
+
+	guard(mutex)(&st->lock);
+
+	/*
+	 * The address is written on the highest weight byte, and the MSB set
+	 * at 1 indicates a read operation.
+	 */
+	addr = FIELD_PREP(ADI_AXI_REG_ADDRESS_MASK, reg) | ADI_AXI_REG_READ_BIT;
+	axi_adc_raw_write(back, addr);
+	axi_adc_raw_read(back, val);
+
+	/* Write 0x0 on the bus to get back to ADC mode */
+	axi_adc_raw_write(back, 0);
+
+	return 0;
+}
+
+static int ad7606_bus_reg_write(struct iio_backend *back, u32 reg, u32 val)
+{
+	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
+	u32 buf;
+
+	guard(mutex)(&st->lock);
+
+	/* Write any register to switch to register mode */
+	axi_adc_raw_write(back, 0xaf00);
+
+	buf = FIELD_PREP(ADI_AXI_REG_ADDRESS_MASK, reg) |
+	      FIELD_PREP(ADI_AXI_REG_VALUE_MASK, val);
+	axi_adc_raw_write(back, buf);
+
+	/* Write 0x0 on the bus to get back to ADC mode */
+	axi_adc_raw_write(back, 0);
+
+	return 0;
+}
+
 static void axi_adc_free_buffer(struct iio_backend *back,
 				struct iio_buffer *buffer)
 {
@@ -498,6 +578,7 @@ static const struct axi_adc_info adc_ad7606 = {
 /* 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 = &adc_generic },
+	{ .compatible = "adi,axi-ad7606x", .data = &adc_ad7606 },
 	{ /* end of list */ }
 };
 MODULE_DEVICE_TABLE(of, adi_axi_adc_of_match);

-- 
2.47.0

[PATCH v4 7/9] iio: adc: ad7606: protect register access

[Angelo Dureghello]

From: Angelo Dureghello <adureghello@baylibre.com>

Protect register (and bus) access from concurrent
read / write. Needed in the backend operating mode.

Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
 drivers/iio/adc/ad7606.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c
index 7985570ed152..07656fdd602e 100644
--- a/drivers/iio/adc/ad7606.c
+++ b/drivers/iio/adc/ad7606.c
@@ -862,7 +862,12 @@ static int ad7606_write_raw(struct iio_dev *indio_dev,
 		}
 		val = (val * MICRO) + val2;
 		i = find_closest(val, scale_avail_uv, cs->num_scales);
+
+		ret = iio_device_claim_direct_mode(indio_dev);
+		if (ret < 0)
+			return ret;
 		ret = st->write_scale(indio_dev, ch, i + cs->reg_offset);
+		iio_device_release_direct_mode(indio_dev);
 		if (ret < 0)
 			return ret;
 		cs->range = i;
@@ -873,7 +878,12 @@ static int ad7606_write_raw(struct iio_dev *indio_dev,
 			return -EINVAL;
 		i = find_closest(val, st->oversampling_avail,
 				 st->num_os_ratios);
+
+		ret = iio_device_claim_direct_mode(indio_dev);
+		if (ret < 0)
+			return ret;
 		ret = st->write_os(indio_dev, i);
+		iio_device_release_direct_mode(indio_dev);
 		if (ret < 0)
 			return ret;
 		st->oversampling = st->oversampling_avail[i];

-- 
2.47.0

[PATCH v4 8/9] iio: adc: ad7606: change channel macros parameters

[Angelo Dureghello]

From: Guillaume Stols <gstols@baylibre.com>

Add the possibility to pass the *_available parameters to the main
macro.
This is a preparation to add the new channels for software mode and
hardware mode in iio backend mode more easily.

Signed-off-by: Guillaume Stols <gstols@baylibre.com>
---
 drivers/iio/adc/ad7606.h | 51 ++++++++++++++++++++++++------------------------
 1 file changed, 25 insertions(+), 26 deletions(-)

diff --git a/drivers/iio/adc/ad7606.h b/drivers/iio/adc/ad7606.h
index 7a044b499cfe..a35b526f3915 100644
--- a/drivers/iio/adc/ad7606.h
+++ b/drivers/iio/adc/ad7606.h
@@ -40,37 +40,19 @@
 #define AD7606_RANGE_CH_ADDR(ch)	(0x03 + ((ch) >> 1))
 #define AD7606_OS_MODE			0x08
 
-#define AD760X_CHANNEL(num, mask_sep, mask_type, mask_all, bits) {	\
+#define AD760X_CHANNEL(num, mask_sep, mask_type, mask_all,	\
+		mask_sep_avail, mask_all_avail, bits) {		\
 		.type = IIO_VOLTAGE,				\
 		.indexed = 1,					\
 		.channel = num,					\
 		.address = num,					\
 		.info_mask_separate = mask_sep,			\
+		.info_mask_separate_available =			\
+			mask_sep_avail,				\
 		.info_mask_shared_by_type = mask_type,		\
 		.info_mask_shared_by_all = mask_all,		\
-		.scan_index = num,				\
-		.scan_type = {					\
-			.sign = 's',				\
-			.realbits = (bits),			\
-			.storagebits = (bits) > 16 ? 32 : 16,	\
-			.endianness = IIO_CPU,			\
-		},						\
-}
-
-#define AD7606_SW_CHANNEL(num, bits) {				\
-		.type = IIO_VOLTAGE,				\
-		.indexed = 1,					\
-		.channel = num,					\
-		.address = num,					\
-		.info_mask_separate =				\
-			BIT(IIO_CHAN_INFO_RAW) |		\
-			BIT(IIO_CHAN_INFO_SCALE),		\
-		.info_mask_separate_available =			\
-			BIT(IIO_CHAN_INFO_SCALE),		\
-		.info_mask_shared_by_all =			\
-			BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
 		.info_mask_shared_by_all_available =		\
-			BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
+			mask_all_avail,				\
 		.scan_index = num,				\
 		.scan_type = {					\
 			.sign = 's',				\
@@ -80,14 +62,30 @@
 		},						\
 }
 
+#define AD7606_SW_CHANNEL(num, bits)			\
+	AD760X_CHANNEL(num,				\
+		/* mask separate */			\
+		BIT(IIO_CHAN_INFO_RAW) |		\
+		BIT(IIO_CHAN_INFO_SCALE),		\
+		/* mask type */				\
+		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
+		/* mask all */				\
+		0,					\
+		/* mask separate available */		\
+		BIT(IIO_CHAN_INFO_SCALE),		\
+		/* mask all available */		\
+		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
+		bits)
+
 #define AD7605_CHANNEL(num)				\
 	AD760X_CHANNEL(num, BIT(IIO_CHAN_INFO_RAW),	\
-		BIT(IIO_CHAN_INFO_SCALE), 0, 16)
+		BIT(IIO_CHAN_INFO_SCALE), 0, 0, 0, 16)
 
 #define AD7606_CHANNEL(num, bits)			\
 	AD760X_CHANNEL(num, BIT(IIO_CHAN_INFO_RAW),	\
 		BIT(IIO_CHAN_INFO_SCALE),		\
-		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), bits)
+		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
+		0, 0, bits)
 
 #define AD7616_CHANNEL(num)	AD7606_SW_CHANNEL(num, 16)
 
@@ -95,7 +93,8 @@
 	AD760X_CHANNEL(num, 0,				\
 		BIT(IIO_CHAN_INFO_SCALE),		\
 		BIT(IIO_CHAN_INFO_SAMP_FREQ) |		\
-		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), 16)
+		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),  \
+		0, 0, 16)
 
 struct ad7606_state;
 

-- 
2.47.0

[PATCH v4 9/9] iio: adc: ad7606: add support for writing registers when using backend

[Angelo Dureghello]

From: Guillaume Stols <gstols@baylibre.com>

Add the logic for effectively enabling the software mode for the
iio-backend, i.e. enabling the software mode channel configuration and
implementing the register writing functions.

Signed-off-by: Guillaume Stols <gstols@baylibre.com>
Co-developed-by: Angelo Dureghello <adureghello@baylibre.com>
Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
 drivers/iio/adc/ad7606.h     | 15 +++++++++++++
 drivers/iio/adc/ad7606_par.c | 52 ++++++++++++++++++++++++++++++++++++++++----
 2 files changed, 63 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/adc/ad7606.h b/drivers/iio/adc/ad7606.h
index a35b526f3915..71a30525eaab 100644
--- a/drivers/iio/adc/ad7606.h
+++ b/drivers/iio/adc/ad7606.h
@@ -96,6 +96,21 @@
 		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),  \
 		0, 0, 16)
 
+#define AD7606_BI_SW_CHANNEL(num)			\
+	AD760X_CHANNEL(num,				\
+		/* mask separate */			\
+		BIT(IIO_CHAN_INFO_SCALE),		\
+		/* mask type */				\
+		0,					\
+		/* mask all */				\
+		BIT(IIO_CHAN_INFO_SAMP_FREQ) |		\
+		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
+		/* mask separate available */		\
+		BIT(IIO_CHAN_INFO_SCALE),		\
+		/* mask all available */		\
+		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
+		16)
+
 struct ad7606_state;
 
 typedef int (*ad7606_scale_setup_cb_t)(struct iio_dev *indio_dev,
diff --git a/drivers/iio/adc/ad7606_par.c b/drivers/iio/adc/ad7606_par.c
index 64733b607aa8..335fb481bfde 100644
--- a/drivers/iio/adc/ad7606_par.c
+++ b/drivers/iio/adc/ad7606_par.c
@@ -19,6 +19,7 @@
 #include <linux/iio/iio.h>
 
 #include "ad7606.h"
+#include "ad7606_bus_iface.h"
 
 static const struct iio_chan_spec ad7606b_bi_channels[] = {
 	AD7606_BI_CHANNEL(0),
@@ -31,7 +32,19 @@ static const struct iio_chan_spec ad7606b_bi_channels[] = {
 	AD7606_BI_CHANNEL(7),
 };
 
-static int ad7606_bi_update_scan_mode(struct iio_dev *indio_dev, const unsigned long *scan_mask)
+static const struct iio_chan_spec ad7606b_bi_sw_channels[] = {
+	AD7606_BI_SW_CHANNEL(0),
+	AD7606_BI_SW_CHANNEL(1),
+	AD7606_BI_SW_CHANNEL(2),
+	AD7606_BI_SW_CHANNEL(3),
+	AD7606_BI_SW_CHANNEL(4),
+	AD7606_BI_SW_CHANNEL(5),
+	AD7606_BI_SW_CHANNEL(6),
+	AD7606_BI_SW_CHANNEL(7),
+};
+
+static int ad7606_par_bus_update_scan_mode(struct iio_dev *indio_dev,
+					   const unsigned long *scan_mask)
 {
 	struct ad7606_state *st = iio_priv(indio_dev);
 	unsigned int c, ret;
@@ -48,7 +61,8 @@ static int ad7606_bi_update_scan_mode(struct iio_dev *indio_dev, const unsigned
 	return 0;
 }
 
-static int ad7606_bi_setup_iio_backend(struct device *dev, struct iio_dev *indio_dev)
+static int ad7606_par_bus_setup_iio_backend(struct device *dev,
+					    struct iio_dev *indio_dev)
 {
 	struct ad7606_state *st = iio_priv(indio_dev);
 	unsigned int ret, c;
@@ -86,9 +100,39 @@ static int ad7606_bi_setup_iio_backend(struct device *dev, struct iio_dev *indio
 	return 0;
 }
 
+static int ad7606_par_bus_reg_read(struct ad7606_state *st, unsigned int addr)
+{
+	struct ad7606_platform_data *pdata = st->dev->platform_data;
+	int val, ret;
+
+	ret = pdata->bus_reg_read(st->back, addr, &val);
+	if (ret)
+		return ret;
+
+	return val;
+}
+
+static int ad7606_par_bus_reg_write(struct ad7606_state *st, unsigned int addr,
+				    unsigned int val)
+{
+	struct ad7606_platform_data *pdata = st->dev->platform_data;
+
+	return pdata->bus_reg_write(st->back, addr, val);
+}
+
+static int ad7606_par_bus_sw_mode_config(struct iio_dev *indio_dev)
+{
+	indio_dev->channels = ad7606b_bi_sw_channels;
+
+	return 0;
+}
+
 static const struct ad7606_bus_ops ad7606_bi_bops = {
-	.iio_backend_config = ad7606_bi_setup_iio_backend,
-	.update_scan_mode = ad7606_bi_update_scan_mode,
+	.iio_backend_config = ad7606_par_bus_setup_iio_backend,
+	.update_scan_mode = ad7606_par_bus_update_scan_mode,
+	.reg_read = ad7606_par_bus_reg_read,
+	.reg_write = ad7606_par_bus_reg_write,
+	.sw_mode_config = ad7606_par_bus_sw_mode_config,
 };
 
 static int ad7606_par16_read_block(struct device *dev,

-- 
2.47.0

Re: [PATCH v4 1/9] dt-bindings: iio: dac: adi-axi-adc: add ad7606 variant

[Rob Herring (Arm)]

On Mon, 10 Feb 2025 17:10:51 +0100, Angelo Dureghello wrote:
> From: Guillaume Stols <gstols@baylibre.com>
> 
> A new compatible is added to reflect the specialized version of the HDL.
> We use the parallel interface to write the ADC's registers, and
> accessing this interface requires to use ADI_AXI_REG_CONFIG_RD,
> ADI_AXI_REG_CONFIG_WR and ADI_AXI_REG_CONFIG_CTRL in a custom fashion.
> 
> Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
> Signed-off-by: Guillaume Stols <gstols@baylibre.com>
> Co-developed-by: Angelo Dureghello <adureghello@baylibre.com>
> Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
> ---
>  .../devicetree/bindings/iio/adc/adi,axi-adc.yaml   | 70 +++++++++++++++++++++-
>  1 file changed, 69 insertions(+), 1 deletion(-)
> 

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.example.dtb: adc@0: pwm-names: ['convst1'] is too short
	from schema $id: http://devicetree.org/schemas/iio/adc/adi,ad7606.yaml#

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20250210-wip-bl-ad7606_add_backend_sw_mode-v4-1-160df18b1da7@baylibre.com

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.

Re: [PATCH v4 1/9] dt-bindings: iio: dac: adi-axi-adc: add ad7606 variant

[David Lechner]

On 2/10/25 11:19 AM, Rob Herring (Arm) wrote:
> 
> On Mon, 10 Feb 2025 17:10:51 +0100, Angelo Dureghello wrote:
>> From: Guillaume Stols <gstols@baylibre.com>
>>
>> A new compatible is added to reflect the specialized version of the HDL.
>> We use the parallel interface to write the ADC's registers, and
>> accessing this interface requires to use ADI_AXI_REG_CONFIG_RD,
>> ADI_AXI_REG_CONFIG_WR and ADI_AXI_REG_CONFIG_CTRL in a custom fashion.
>>
>> Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
>> Signed-off-by: Guillaume Stols <gstols@baylibre.com>
>> Co-developed-by: Angelo Dureghello <adureghello@baylibre.com>
>> Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
>> ---
>>  .../devicetree/bindings/iio/adc/adi,axi-adc.yaml   | 70 +++++++++++++++++++++-
>>  1 file changed, 69 insertions(+), 1 deletion(-)
>>
> 
> My bot found errors running 'make dt_binding_check' on your patch:
> 
> yamllint warnings/errors:
> 
> dtschema/dtc warnings/errors:
> /builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/iio/adc/adi,axi-adc.example.dtb: adc@0: pwm-names: ['convst1'] is too short
> 	from schema $id: http://devicetree.org/schemas/iio/adc/adi,ad7606.yaml#

Caused by missing dependency from v3 that Jonathan already picked up.

https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git/commit/?h=fixes-togreg&id=02ccd7e5d81af4ae20852fc1ad67e7d943fa5778

> 
> doc reference errors (make refcheckdocs):
> 
> See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20250210-wip-bl-ad7606_add_backend_sw_mode-v4-1-160df18b1da7@baylibre.com
> 
> The base for the series is generally the latest rc1. A different dependency
> should be noted in *this* patch.
> 
> If you already ran 'make dt_binding_check' and didn't see the above
> error(s), then make sure 'yamllint' is installed and dt-schema is up to
> date:
> 
> pip3 install dtschema --upgrade
> 
> Please check and re-submit after running the above command yourself. Note
> that DT_SCHEMA_FILES can be set to your schema file to speed up checking
> your schema. However, it must be unset to test all examples with your schema.
> 

Re: [PATCH v4 0/9] add support for Software mode on AD7606's iio backend driver

[Jonathan Cameron]

On Mon, 10 Feb 2025 17:10:50 +0100
Angelo Dureghello <adureghello@baylibre.com> wrote:

> The previous series added iio_backend mode, but the configuration for this
> mode was only possible through GPIOs (Hardware mode). Here, we add support
> for configuring the chip using its registers (Software mode).
> 
> The bus access is based on Angelo's ad3552 implementation, that is we have
> a particular compatible for the backend (here axi-adc) version supporting
> the ad7606's register writing, and the ad7606 is defined as a child node
> of the backend in the devicetree. Small changes are added to make the code
> a bit more straightforward to understand, and more compact.
> 
> Signed-off-by: Guillaume Stols <gstols@baylibre.com>
> Co-developed-by: Angelo Dureghello <adureghello@baylibre.com>
> Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
Applied to the togreg branch of iio.git.  Briefly pushed that out as testing
to let 0-day take a first look.
Thanks,

Jonathan