[PATCH v5 0/3] add support for ad777x family

[PATCH v5 0/3] add support for ad777x family

[Ramona Alexandra Nechita]

v4:
  * https://lore.kernel.org/all/20240724155517.12470-1-ramona.nechita@analog.com/
v5:
  * Patch1:
    - removed yaml unnecessary nodes
    - removed vref_supply from yaml altogether, as it is not used by the driver
    - documented interrupt line in yaml file
    - updated commit message with short description
  * Patch2:
    - version downgrade in sysfs-bus-iio file due to combinig the two drivers'
    attributes together (one was available in 6.1 and the other in 6.2 and it
    seemed right to leave it as 6.1)
  * Patch3:
    - removed comments with old code
    - fix commit messages
    - removed power_mode from driver private structure
    - used spi_write for ad7779_spi_write function
    - fixed various indents and line wraps, typos etc
    - used goto in trig_handler to get rid of duplicate code
    - switched to iio_for_each_active_channel
    - removed unnecessary trig setting (done by devm already)
    - removed __maybe_unused from driver suspend/resume functions

Ramona Alexandra Nechita (3):
  dt-bindings: iio: adc: add a7779 doc
  Documentation: ABI: added filter mode doc in sysfs-bus-iio
  drivers: iio: adc: add support for ad777x family

 Documentation/ABI/testing/sysfs-bus-iio       |  22 +
 .../ABI/testing/sysfs-bus-iio-adc-ad4130      |  46 -
 .../bindings/iio/adc/adi,ad7779.yaml          |  84 ++
 drivers/iio/adc/Kconfig                       |  11 +
 drivers/iio/adc/Makefile                      |   1 +
 drivers/iio/adc/ad7779.c                      | 917 ++++++++++++++++++
 6 files changed, 1035 insertions(+), 46 deletions(-)
 delete mode 100644 Documentation/ABI/testing/sysfs-bus-iio-adc-ad4130
 create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,ad7779.yaml
 create mode 100644 drivers/iio/adc/ad7779.c

-- 
2.43.0

[PATCH v5 1/3] dt-bindings: iio: adc: add a7779 doc

[Ramona Alexandra Nechita]

Add dt bindings for AD7779 8-channel, simultaneous sampling ADC
family with eight full Σ-Δ ADCs on chip and ultra-low input
current to allow direct sensor connection.

Signed-off-by: Ramona Alexandra Nechita <ramona.nechita@analog.com>
---
 .../bindings/iio/adc/adi,ad7779.yaml          | 84 +++++++++++++++++++
 1 file changed, 84 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,ad7779.yaml

diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7779.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7779.yaml
new file mode 100644
index 000000000000..0ed5ec5dd8fe
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7779.yaml
@@ -0,0 +1,84 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/adi,ad7779.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices AD777X family 8-Channel, 24-Bit, Simultaneous Sampling ADCs
+
+maintainers:
+  - Ramona Nechita <ramona.nechita@analog.com>
+
+description: |
+  The AD777X family consist of 8-channel, simultaneous sampling analog-to-
+  digital converter (ADC). Eight full Σ-Δ ADCs are on-chip. The
+  AD7771 provides an ultralow input current to allow direct sensor
+  connection. Each input channel has a programmable gain stage
+  allowing gains of 1, 2, 4, and 8 to map lower amplitude sensor
+  outputs into the full-scale ADC input range, maximizing the
+  dynamic range of the signal chain.
+
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ad7770.pdf
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ad7771.pdf
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ad7779.pdf
+
+$ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+  compatible:
+    enum:
+      - adi,ad7770
+      - adi,ad7771
+      - adi,ad7779
+
+  reg:
+    maxItems: 1
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+  clocks:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+    description:
+      Interrupt line for DRDY signal which indicates the end of conversion
+      independently of the interface selected to read back the Σ-∆ conversion.
+
+  start-gpios:
+    description:
+      Pin that controls start synchronization pulse.
+    maxItems: 1
+
+  reset-gpios:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - interrupts
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        adc@0 {
+          compatible = "adi,ad7779";
+          reg = <0>;
+          vref-supply = <&vref>;
+          start-gpios = <&gpio0 87 GPIO_ACTIVE_LOW>;
+          reset-gpios = <&gpio0 93 GPIO_ACTIVE_LOW>;
+          clocks = <&adc_clk>;
+        };
+    };
+...
-- 
2.43.0

[PATCH v5 2/3] Documentation: ABI: added filter mode doc in sysfs-bus-iio

[Ramona Alexandra Nechita]

The filter mode / filter type property is used for ad4130
and ad7779 drivers, therefore the ABI doc file for ad4130
was removed, merging both of them in the sysfs-bus-iio.

Signed-off-by: Ramona Alexandra Nechita <ramona.nechita@analog.com>
---
 Documentation/ABI/testing/sysfs-bus-iio       | 22 +++++++++
 .../ABI/testing/sysfs-bus-iio-adc-ad4130      | 46 -------------------
 2 files changed, 22 insertions(+), 46 deletions(-)
 delete mode 100644 Documentation/ABI/testing/sysfs-bus-iio-adc-ad4130

diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index 345d58535dc9..aac41e69aa43 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -2265,6 +2265,28 @@ Description:
 		An example format is 16-bytes, 2-digits-per-byte, HEX-string
 		representing the sensor unique ID number.
 
+What:		/sys/bus/iio/devices/iio:deviceX/filter_type_available
+What:		/sys/bus/iio/devices/iio:deviceX/in_voltage-voltage_filter_mode_available
+KernelVersion:	6.1
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Reading returns a list with the possible filter modes. Options
+		for the attribute:
+			* "sinc3"	- The digital sinc3 filter. Moderate 1st conversion time.
+		    Good noise performance.
+			* "sinc4"       - Sinc 4. Excellent noise performance. Long
+			1st conversion time.
+			* "sinc5"	- The digital sinc5 filter. Excellent noise performance
+			* "sinc4+sinc1" - Sinc4 + averaging by 8. Low 1st conversion
+		    time.
+			* "sinc3+rej60" - Sinc3 + 60Hz rejection.
+			* "sinc3+sinc1" - Sinc3 + averaging by 8. Low 1st conversion
+		    time.
+			* "sinc3+pf1"   - Sinc3 + device specific Post Filter 1.
+			* "sinc3+pf2"   - Sinc3 + device specific Post Filter 2.
+			* "sinc3+pf3"   - Sinc3 + device specific Post Filter 3.
+			* "sinc3+pf4"   - Sinc3 + device specific Post Filter 4.
+
 What:		/sys/.../events/in_proximity_thresh_either_runningperiod
 KernelVersion:	6.6
 Contact:	linux-iio@vger.kernel.org
diff --git a/Documentation/ABI/testing/sysfs-bus-iio-adc-ad4130 b/Documentation/ABI/testing/sysfs-bus-iio-adc-ad4130
deleted file mode 100644
index f24ed6687e90..000000000000
--- a/Documentation/ABI/testing/sysfs-bus-iio-adc-ad4130
+++ /dev/null
@@ -1,46 +0,0 @@
-What:		/sys/bus/iio/devices/iio:deviceX/in_voltage-voltage_filter_mode_available
-KernelVersion:  6.2
-Contact:	linux-iio@vger.kernel.org
-Description:
-		Reading returns a list with the possible filter modes.
-
-		  * "sinc4"       - Sinc 4. Excellent noise performance. Long
-                    1st conversion time. No natural 50/60Hz rejection.
-
-		  * "sinc4+sinc1" - Sinc4 + averaging by 8. Low 1st conversion
-		    time.
-
-		  * "sinc3"	      - Sinc3. Moderate 1st conversion time.
-		    Good noise performance.
-
-		  * "sinc3+rej60" - Sinc3 + 60Hz rejection. At a sampling
-		    frequency of 50Hz, achieves simultaneous 50Hz and 60Hz
-		    rejection.
-
-		  * "sinc3+sinc1" - Sinc3 + averaging by 8. Low 1st conversion
-		    time. Best used with a sampling frequency of at least
-		    216.19Hz.
-
-		  * "sinc3+pf1"   - Sinc3 + Post Filter 1. 53dB rejection @
-		    50Hz, 58dB rejection @ 60Hz.
-
-		  * "sinc3+pf2"   - Sinc3 + Post Filter 2. 70dB rejection @
-		    50Hz, 70dB rejection @ 60Hz.
-
-		  * "sinc3+pf3"   - Sinc3 + Post Filter 3. 99dB rejection @
-		    50Hz, 103dB rejection @ 60Hz.
-
-		  * "sinc3+pf4"   - Sinc3 + Post Filter 4. 103dB rejection @
-		    50Hz, 109dB rejection @ 60Hz.
-
-What:		/sys/bus/iio/devices/iio:deviceX/in_voltageY-voltageZ_filter_mode
-KernelVersion:  6.2
-Contact:	linux-iio@vger.kernel.org
-Description:
-		Set the filter mode of the differential channel. When the filter
-		mode changes, the in_voltageY-voltageZ_sampling_frequency and
-		in_voltageY-voltageZ_sampling_frequency_available attributes
-		might also change to accommodate the new filter mode.
-		If the current sampling frequency is out of range for the new
-		filter mode, the sampling frequency will be changed to the
-		closest valid one.
-- 
2.43.0

[PATCH v5 3/3] drivers: iio: adc: add support for ad777x family

[Ramona Alexandra Nechita]

Add support for AD7770, AD7771, AD7779 ADCs. The device is capable of
sending out data both on DOUT lines interface,as on the SDO line.
The driver currently implements only the SDO data streaming mode. SPI
communication is used alternatively for accessing registers and streaming
data. Register access are protected by crc8.

Signed-off-by: Ramona Alexandra Nechita <ramona.nechita@analog.com>
---
 drivers/iio/adc/Kconfig  |  11 +
 drivers/iio/adc/Makefile |   1 +
 drivers/iio/adc/ad7779.c | 917 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 929 insertions(+)
 create mode 100644 drivers/iio/adc/ad7779.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 88e8ce2e78b3..fe6d56225fa1 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -267,6 +267,17 @@ config AD7768_1
 	  To compile this driver as a module, choose M here: the module will be
 	  called ad7768-1.
 
+config AD7779
+	tristate "Analog Devices AD7779 ADC driver"
+	depends on SPI
+	select IIO_BUFFER
+	help
+	  Say yes here to build support for Analog Devices AD777X family
+	  (AD7770, AD7771, AD7779) analog to digital converter (ADC).
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called ad7779.
+
 config AD7780
 	tristate "Analog Devices AD7780 and similar ADCs driver"
 	depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 8b80664c6d6b..3d28ea490e01 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_AD7606_IFACE_SPI) += ad7606_spi.o
 obj-$(CONFIG_AD7606) += ad7606.o
 obj-$(CONFIG_AD7766) += ad7766.o
 obj-$(CONFIG_AD7768_1) += ad7768-1.o
+obj-$(CONFIG_AD7779) += ad7779.o
 obj-$(CONFIG_AD7780) += ad7780.o
 obj-$(CONFIG_AD7791) += ad7791.o
 obj-$(CONFIG_AD7793) += ad7793.o
diff --git a/drivers/iio/adc/ad7779.c b/drivers/iio/adc/ad7779.c
new file mode 100644
index 000000000000..05ae72257c9e
--- /dev/null
+++ b/drivers/iio/adc/ad7779.c
@@ -0,0 +1,917 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * AD7770, AD7771, AD7779 ADC
+ *
+ * Copyright 2023-2024 Analog Devices Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitmap.h>
+#include <linux/clk.h>
+#include <linux/crc8.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+#include <linux/string.h>
+#include <linux/units.h>
+
+#include <asm/unaligned.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+
+#define AD7779_SPI_READ_CMD			BIT(7)
+
+#define AD7779_DISABLE_SD			BIT(7)
+
+#define AD7779_REG_CH_DISABLE			0x08
+#define AD7779_REG_CH_SYNC_OFFSET(ch)		(0x09 + (ch))
+#define AD7779_REG_CH_CONFIG(ch)		(0x00 + (ch))
+#define AD7779_REG_GENERAL_USER_CONFIG_1	0x11
+#define AD7779_REG_GENERAL_USER_CONFIG_2	0x12
+#define AD7779_REG_GENERAL_USER_CONFIG_3	0x13
+#define AD7779_REG_DOUT_FORMAT			0x14
+#define AD7779_REG_ADC_MUX_CONFIG		0x15
+#define AD7779_REG_GPIO_CONFIG			0x17
+#define AD7779_REG_BUFFER_CONFIG_1		0x19
+#define AD7779_REG_GLOBAL_MUX_CONFIG		0x16
+#define AD7779_REG_BUFFER_CONFIG_2		0x1A
+#define AD7779_REG_GPIO_DATA			0x18
+#define AD7779_REG_CH_OFFSET_UPPER_BYTE(ch)	(0x1C + (ch) * 6)
+#define AD7779_REG_CH_OFFSET_LOWER_BYTE(ch)	(0x1E + (ch) * 6)
+#define AD7779_REG_CH_GAIN_UPPER_BYTE(ch)	(0x1F + (ch) * 6)
+#define AD7779_REG_CH_OFFSET_MID_BYTE(ch)	(0x1D + (ch) * 6)
+#define AD7779_REG_CH_GAIN_MID_BYTE(ch)		(0x20 + (ch) * 6)
+#define AD7779_REG_CH_ERR_REG(ch)		(0x4C + (ch))
+#define AD7779_REG_CH0_1_SAT_ERR		0x54
+#define AD7779_REG_CH_GAIN_LOWER_BYTE(ch)	(0x21 + (ch) * 6)
+#define AD7779_REG_CH2_3_SAT_ERR		0x55
+#define AD7779_REG_CH4_5_SAT_ERR		0x56
+#define AD7779_REG_CH6_7_SAT_ERR		0x57
+#define AD7779_REG_CHX_ERR_REG_EN		0x58
+#define AD7779_REG_GEN_ERR_REG_1		0x59
+#define AD7779_REG_GEN_ERR_REG_1_EN		0x5A
+#define AD7779_REG_GEN_ERR_REG_2		0x5B
+#define AD7779_REG_GEN_ERR_REG_2_EN		0x5C
+#define AD7779_REG_STATUS_REG_1			0x5D
+#define AD7779_REG_STATUS_REG_2			0x5E
+#define AD7779_REG_STATUS_REG_3			0x5F
+#define AD7779_REG_SRC_N_MSB			0x60
+#define AD7779_REG_SRC_N_LSB			0x61
+#define AD7779_REG_SRC_IF_MSB			0x62
+#define AD7779_REG_SRC_IF_LSB			0x63
+#define AD7779_REG_SRC_UPDATE			0x64
+
+#define AD7779_FILTER_MSK			BIT(6)
+#define AD7779_MOD_POWERMODE_MSK		BIT(6)
+#define AD7779_MOD_PDB_REFOUT_MSK		BIT(4)
+#define AD7779_MOD_SPI_EN_MSK			BIT(4)
+#define AD7779_USRMOD_INIT_MSK			GENMASK(6,4)
+
+/* AD7779_REG_DOUT_FORMAT */
+#define AD7779_DOUT_FORMAT_MSK			GENMASK(7, 6)
+#define AD7779_DOUT_HEADER_FORMAT		BIT(5)
+#define AD7779_DCLK_CLK_DIV_MSK			GENMASK(3, 1)
+
+#define AD7779_REFMUX_CTRL_MSK			GENMASK(7, 6)
+#define AD7779_SPI_CRC_EN_MSK			BIT(0)
+
+#define AD7779_MAXCLK_LOWPOWER			4096000
+#define AD7779_NUM_CHANNELS			8
+#define AD7779_RESET_BUF_SIZE			8
+#define AD7779_CHAN_DATA_SIZE			4
+
+#define AD7779_LOWPOWER_DIV			512
+#define AD7779_HIGHPOWER_DIV			2048
+
+#define AD7779_SINC3_MAXFREQ			(16 * HZ_PER_KHZ)
+#define AD7779_SINC5_MAXFREQ			(128 * HZ_PER_KHZ)
+
+#define AD7779_DEFAULT_SAMPLING_FREQ		(8 * HZ_PER_KHZ)
+#define AD7779_DEFAULT_SAMPLING_2LINE		(4 * HZ_PER_KHZ)
+#define AD7779_DEFAULT_SAMPLING_1LINE		(2 * HZ_PER_KHZ)
+
+#define AD7779_SPIMODE_MAX_SAMP_FREQ		(16 * HZ_PER_KHZ)
+
+#define GAIN_REL				0x555555
+#define AD7779_FREQ_MSB_MSK			GENMASK(15, 8)
+#define AD7779_FREQ_LSB_MSK			GENMASK(7, 0)
+#define AD7779_UPPER				GENMASK(23, 16)
+#define AD7779_MID				GENMASK(15, 8)
+#define AD7779_LOWER				GENMASK(7, 0)
+
+#define AD7779_REG_MSK		GENMASK(6, 0)
+
+#define AD7779_CRC8_POLY			0x07
+DECLARE_CRC8_TABLE(ad7779_crc8_table);
+
+enum ad7779_filter {
+	AD7779_SINC3,
+	AD7779_SINC5,
+};
+
+enum ad7779_variant {
+	ad7770,
+	ad7771,
+	ad7779,
+};
+
+enum ad7779_power_mode {
+	AD7779_LOW_POWER,
+	AD7779_HIGH_POWER,
+};
+
+struct ad7779_chip_info {
+	const char *name;
+	struct iio_chan_spec const *channels;
+};
+
+struct ad7779_state {
+	struct spi_device *spi;
+	const struct ad7779_chip_info *chip_info;
+	struct clk *mclk;
+	struct iio_trigger *trig;
+	struct completion completion;
+	unsigned int sampling_freq;
+	enum ad7779_filter filter_enabled;
+	/*
+	 * DMA (thus cache coherency maintenance) requires the
+	 * transfer buffers to live in their own cache lines.
+	 */
+	u8			reg_rx_buf[3] __aligned(IIO_DMA_MINALIGN);
+	u8			reg_tx_buf[3];
+	u32			spidata_rx[8];
+	u32			spidata_tx[8];
+	u8			reset_buf[8];
+};
+
+static const char * const ad7779_filter_type[] = {
+	[AD7779_SINC3] = "sinc3",
+	[AD7779_SINC5] = "sinc5",
+};
+
+static int ad7779_spi_read(struct ad7779_state *st, u8 reg, u8 *rbuf)
+{
+	int ret;
+	int length = 3;
+	u8 crc_buf[2];
+	u8 exp_crc = 0;
+	struct spi_transfer reg_read_tr[] = {
+		{
+			.tx_buf = st->reg_tx_buf,
+			.rx_buf = st->reg_rx_buf,
+		},
+	};
+
+	if (reg == AD7779_REG_GEN_ERR_REG_1_EN)
+		length = 2;
+	reg_read_tr[0].len = length;
+
+	st->reg_tx_buf[0] = AD7779_SPI_READ_CMD | FIELD_GET(AD7779_REG_MSK, reg);
+	st->reg_tx_buf[1] = 0;
+	st->reg_tx_buf[2] = crc8(ad7779_crc8_table, st->reg_tx_buf, 2, 0);
+
+	ret = spi_sync_transfer(st->spi, reg_read_tr, ARRAY_SIZE(reg_read_tr));
+	if (ret)
+		return ret;
+
+	crc_buf[0] = AD7779_SPI_READ_CMD | FIELD_GET(AD7779_REG_MSK, reg);
+	crc_buf[1] = st->reg_rx_buf[1];
+	exp_crc = crc8(ad7779_crc8_table, crc_buf, 2, 0);
+	if (reg != AD7779_REG_GEN_ERR_REG_1_EN && exp_crc != st->reg_rx_buf[2]) {
+		dev_err(&st->spi->dev, "Bad CRC %x, expected %x",
+			st->reg_rx_buf[2], exp_crc);
+		return -EINVAL;
+	}
+	*rbuf = st->reg_rx_buf[1];
+
+	return 0;
+}
+
+static int ad7779_spi_write(struct ad7779_state *st, u8 reg, u8 val)
+{
+	int length = 3;
+
+	if (reg == AD7779_REG_GEN_ERR_REG_1_EN)
+		length = 2;
+
+	st->reg_tx_buf[0] = FIELD_GET(AD7779_REG_MSK, reg);
+	st->reg_tx_buf[1] = val;
+	st->reg_tx_buf[2] = crc8(ad7779_crc8_table, st->reg_tx_buf, 2, 0);
+
+	return spi_write(st->spi, st->reg_tx_buf, length);
+}
+
+static int ad7779_spi_write_mask(struct ad7779_state *st, u8 reg, u8 mask,
+				 u8 val)
+{
+	int ret;
+	u8 regval, data;
+
+	ret = ad7779_spi_read(st, reg, &data);
+	if (ret)
+		return ret;
+
+	regval = data;
+	regval &= ~mask;
+	regval |= val;
+
+	if (regval == data)
+		return 0;
+
+	return ad7779_spi_write(st, reg, regval);
+}
+
+static int ad7779_reg_access(struct iio_dev *indio_dev,
+			     unsigned int reg,
+			     unsigned int writeval,
+			     unsigned int *readval)
+{
+	struct ad7779_state *st = iio_priv(indio_dev);
+
+	if (readval)
+		return ad7779_spi_read(st, reg, (u8 *)readval);
+
+	return ad7779_spi_write(st, reg, writeval);
+}
+
+static int ad7779_set_sampling_frequency(struct ad7779_state *st,
+					 unsigned int sampling_freq)
+{
+	int ret;
+	unsigned int dec;
+	unsigned int div;
+	unsigned int decimal;
+	int temp;
+	unsigned int kfreq;
+
+	if (st->filter_enabled == AD7779_SINC3 &&
+	    sampling_freq > AD7779_SINC3_MAXFREQ)
+		return -EINVAL;
+
+	if (st->filter_enabled == AD7779_SINC5 &&
+	    sampling_freq > AD7779_SINC5_MAXFREQ)
+		return -EINVAL;
+
+	if (sampling_freq > AD7779_SPIMODE_MAX_SAMP_FREQ)
+		return -EINVAL;
+
+	div = AD7779_HIGHPOWER_DIV;
+
+	kfreq = sampling_freq / KILO;
+	dec = div / kfreq;
+
+	ret = ad7779_spi_write(st, AD7779_REG_SRC_N_MSB,
+			       FIELD_GET(AD7779_FREQ_MSB_MSK, dec));
+	if (ret)
+		return ret;
+	ret = ad7779_spi_write(st, AD7779_REG_SRC_N_LSB,
+			       FIELD_GET(AD7779_FREQ_LSB_MSK, dec));
+	if (ret)
+		return ret;
+
+	if (div % kfreq) {
+		temp = (div * KILO) / kfreq;
+		decimal = ((temp -  dec * KILO) << 16) / KILO;
+		ret = ad7779_spi_write(st, AD7779_REG_SRC_N_MSB,
+				       FIELD_GET(AD7779_FREQ_MSB_MSK, decimal));
+		if (ret)
+			return ret;
+		ret = ad7779_spi_write(st, AD7779_REG_SRC_N_LSB,
+				       FIELD_GET(AD7779_FREQ_LSB_MSK, decimal));
+		if (ret)
+			return ret;
+	} else {
+		ret = ad7779_spi_write(st, AD7779_REG_SRC_N_MSB,
+				       FIELD_GET(AD7779_FREQ_MSB_MSK, 0x0));
+		if (ret)
+			return ret;
+		ret = ad7779_spi_write(st, AD7779_REG_SRC_N_LSB,
+				       FIELD_GET(AD7779_FREQ_LSB_MSK, 0x0));
+		if (ret)
+			return ret;
+	}
+	ret = ad7779_spi_write(st, AD7779_REG_SRC_UPDATE, 0x1);
+	if (ret)
+		return ret;
+
+	/* SRC update settling time */
+	fsleep(15);
+	ret = ad7779_spi_write(st, AD7779_REG_SRC_UPDATE, 0x0);
+	if (ret)
+		return ret;
+
+	/* SRC update settling time */
+	fsleep(15);
+
+	st->sampling_freq = sampling_freq;
+
+	return 0;
+}
+
+static int ad7779_get_filter(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan)
+{
+	struct ad7779_state *st = iio_priv(indio_dev);
+	u8 temp;
+	int ret;
+
+	ret = ad7779_spi_read(st, AD7779_REG_GENERAL_USER_CONFIG_2, &temp);
+	if (ret)
+		return ret;
+
+	return FIELD_GET(AD7779_FILTER_MSK, temp);
+}
+
+static int ad7779_set_filter(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     unsigned int mode)
+{
+	struct ad7779_state *st = iio_priv(indio_dev);
+	int ret;
+
+	ret = ad7779_spi_write_mask(st,
+				    AD7779_REG_GENERAL_USER_CONFIG_2,
+				    AD7779_FILTER_MSK,
+				    FIELD_PREP(AD7779_FILTER_MSK, mode));
+	if (ret < 0)
+		return ret;
+
+	ret = ad7779_set_sampling_frequency(st, st->sampling_freq);
+	if (ret < 0)
+		return ret;
+
+	st->filter_enabled = mode;
+
+	return 0;
+}
+
+static int ad7779_get_calibscale(struct ad7779_state *st, int channel)
+{
+	int ret;
+	u8 calibscale[3];
+
+	ret = ad7779_spi_read(st, AD7779_REG_CH_GAIN_LOWER_BYTE(channel), &calibscale[0]);
+	if (ret)
+		return ret;
+
+	ret = ad7779_spi_read(st, AD7779_REG_CH_GAIN_MID_BYTE(channel), &calibscale[1]);
+	if (ret)
+		return ret;
+
+	ret = ad7779_spi_read(st, AD7779_REG_CH_GAIN_UPPER_BYTE(channel), &calibscale[2]);
+	if (ret)
+		return ret;
+
+	return get_unaligned_be24(calibscale);
+}
+
+static int ad7779_set_calibscale(struct ad7779_state *st, int channel, int val)
+{
+	int ret;
+	unsigned int gain;
+	unsigned long long tmp;
+	u8 gain_bytes[3];
+
+	tmp = val * 5592405LL;
+	gain = DIV_ROUND_CLOSEST_ULL(tmp, MEGA);
+	put_unaligned_be24(gain, gain_bytes);
+	ret = ad7779_spi_write(st,
+			       AD7779_REG_CH_GAIN_UPPER_BYTE(channel),
+			       gain_bytes[0]);
+	if (ret)
+		return ret;
+
+	ret = ad7779_spi_write(st,
+			       AD7779_REG_CH_GAIN_MID_BYTE(channel),
+			       gain_bytes[1]);
+	if (ret)
+		return ret;
+
+	return ad7779_spi_write(st,
+				AD7779_REG_CH_GAIN_LOWER_BYTE(channel),
+				gain_bytes[2]);
+}
+
+static int ad7779_get_calibbias(struct ad7779_state *st, int channel)
+{
+	int ret;
+	u8 calibbias[3];
+
+	ret = ad7779_spi_read(st, AD7779_REG_CH_OFFSET_LOWER_BYTE(channel),
+			      &calibbias[0]);
+	if (ret)
+		return ret;
+
+	ret = ad7779_spi_read(st, AD7779_REG_CH_OFFSET_MID_BYTE(channel),
+				  &calibbias[1]);
+	if (ret)
+		return ret;
+
+	ret = ad7779_spi_read(st,
+			      AD7779_REG_CH_OFFSET_UPPER_BYTE(channel),
+			      &calibbias[2]);
+	if (ret)
+		return ret;
+
+	return get_unaligned_be24(calibbias);
+}
+
+static int ad7779_set_calibbias(struct ad7779_state *st, int channel, int val)
+{
+	int ret;
+	u8 calibbias[3];
+
+	put_unaligned_be24(val, calibbias);
+	ret = ad7779_spi_write(st,
+			       AD7779_REG_CH_OFFSET_UPPER_BYTE(channel),
+			       calibbias[0]);
+	if (ret)
+		return ret;
+
+	ret = ad7779_spi_write(st,
+			       AD7779_REG_CH_OFFSET_MID_BYTE(channel),
+			       calibbias[1]);
+	if (ret)
+		return ret;
+
+	return ad7779_spi_write(st,
+				AD7779_REG_CH_OFFSET_LOWER_BYTE(channel),
+				calibbias[2]);
+}
+
+static int ad7779_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan, int *val,
+			   int *val2, long mask)
+{
+	struct ad7779_state *st = iio_priv(indio_dev);
+
+	iio_device_claim_direct_scoped(return -EBUSY, indio_dev) {
+		switch (mask) {
+		case IIO_CHAN_INFO_CALIBSCALE:
+			*val = ad7779_get_calibscale(st, chan->channel);
+			if (*val < 0)
+				return -EINVAL;
+			*val2 = GAIN_REL;
+			return IIO_VAL_FRACTIONAL;
+		case IIO_CHAN_INFO_CALIBBIAS:
+			*val = ad7779_get_calibbias(st, chan->channel);
+			if (*val < 0)
+				return -EINVAL;
+			return IIO_VAL_INT;
+		case IIO_CHAN_INFO_SAMP_FREQ:
+			*val = st->sampling_freq;
+			if (*val < 0)
+				return -EINVAL;
+			return IIO_VAL_INT;
+		}
+		return -EINVAL;
+	}
+	unreachable();
+}
+
+static int ad7779_write_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan, int val, int val2,
+			    long mask)
+{
+	struct ad7779_state *st = iio_priv(indio_dev);
+
+	iio_device_claim_direct_scoped(return -EBUSY, indio_dev) {
+		switch (mask) {
+		case IIO_CHAN_INFO_CALIBSCALE:
+			return ad7779_set_calibscale(st, chan->channel, val2);
+		case IIO_CHAN_INFO_CALIBBIAS:
+			return ad7779_set_calibbias(st, chan->channel, val);
+		case IIO_CHAN_INFO_SAMP_FREQ:
+			return ad7779_set_sampling_frequency(st, val);
+		default:
+			return -EINVAL;
+		}
+	}
+	unreachable();
+}
+
+static int ad7779_buffer_preenable(struct iio_dev *indio_dev)
+{
+	int ret;
+	struct ad7779_state *st = iio_priv(indio_dev);
+
+	ret = ad7779_spi_write_mask(st,
+				    AD7779_REG_GENERAL_USER_CONFIG_3,
+				    AD7779_MOD_SPI_EN_MSK,
+				    FIELD_PREP(AD7779_MOD_SPI_EN_MSK, 1));
+	if (ret)
+		return ret;
+
+	/*
+	 * DRDY output cannot be disabled at device level therefore we mask
+	 * the irq at host end.
+	 */
+	enable_irq(st->spi->irq);
+
+	return 0;
+}
+
+static int ad7779_buffer_postdisable(struct iio_dev *indio_dev)
+{
+	struct ad7779_state *st = iio_priv(indio_dev);
+
+	disable_irq(st->spi->irq);
+
+	return ad7779_spi_write(st, AD7779_REG_GENERAL_USER_CONFIG_3,
+			       AD7779_DISABLE_SD);
+}
+
+static irqreturn_t ad7779_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct ad7779_state *st = iio_priv(indio_dev);
+	int ret;
+	int bit;
+	int k = 0;
+	/*
+	 * Each channel shifts out HEADER + 24 bits of data therefore 8 * u32
+	 * for the data and 64 bits for the timestamp
+	 */
+	u32 tmp[10];
+
+	struct spi_transfer sd_readback_tr[] = {
+		{
+			.rx_buf = st->spidata_rx,
+			.tx_buf = st->spidata_tx,
+			.len = AD7779_NUM_CHANNELS * AD7779_CHAN_DATA_SIZE,
+		}
+	};
+
+	if (!iio_buffer_enabled(indio_dev))
+		goto exit_handler;
+
+	st->spidata_tx[0] = AD7779_SPI_READ_CMD;
+	ret = spi_sync_transfer(st->spi, sd_readback_tr,
+				ARRAY_SIZE(sd_readback_tr));
+	if (ret) {
+		dev_err(&st->spi->dev,
+			"spi transfer error in irq handler");
+		goto exit_handler;
+	}
+
+	for_each_set_bit(bit, indio_dev->active_scan_mask, AD7779_NUM_CHANNELS - 1)
+		tmp[k++] = st->spidata_rx[bit];
+
+	iio_push_to_buffers_with_timestamp(indio_dev, &tmp[0], pf->timestamp);
+
+exit_handler:
+	iio_trigger_notify_done(indio_dev->trig);
+	return IRQ_HANDLED;
+}
+
+static int ad7779_reset(struct iio_dev *indio_dev, struct gpio_desc *reset_gpio)
+{
+	struct ad7779_state *st = iio_priv(indio_dev);
+	int ret;
+	struct spi_transfer reg_read_tr[] = {
+		{
+			.tx_buf = st->reset_buf,
+			.len = 8,
+		},
+	};
+
+	memset(st->reset_buf, 0xff, sizeof(st->reset_buf));
+
+	if (reset_gpio) {
+		/* Delay for reset to occur is 225 microseconds*/
+		gpiod_set_value(reset_gpio, 1);
+		fsleep(230);
+		return 0;
+	}
+
+	ret = spi_sync_transfer(st->spi, reg_read_tr,
+				ARRAY_SIZE(reg_read_tr));
+	if (ret)
+		return ret;
+
+	/* Delay for reset to occur is 225 microseconds*/
+	fsleep(230);
+
+	return 0;
+}
+
+static const struct iio_info ad7779_info = {
+	.read_raw = ad7779_read_raw,
+	.write_raw = ad7779_write_raw,
+	.debugfs_reg_access = &ad7779_reg_access,
+};
+
+static const struct iio_enum ad7779_filter_enum = {
+	.items = ad7779_filter_type,
+	.num_items = ARRAY_SIZE(ad7779_filter_type),
+	.get = ad7779_get_filter,
+	.set = ad7779_set_filter,
+};
+
+static const struct iio_chan_spec_ext_info ad7779_ext_filter[] = {
+	IIO_ENUM("filter_type", IIO_SHARED_BY_ALL, &ad7779_filter_enum),
+	IIO_ENUM_AVAILABLE("filter_type", IIO_SHARED_BY_ALL,
+				  &ad7779_filter_enum),
+	{ }
+};
+
+#define AD777x_CHAN_S(index, _ext_info)					       \
+	{								       \
+		.type = IIO_VOLTAGE,					       \
+		.info_mask_separate = BIT(IIO_CHAN_INFO_CALIBSCALE)  |	       \
+				      BIT(IIO_CHAN_INFO_CALIBBIAS),	       \
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),       \
+		.address = (index),					       \
+		.indexed = 1,						       \
+		.channel = (index),					       \
+		.scan_index = (index),					       \
+		.ext_info = (_ext_info),				       \
+		.scan_type = {						       \
+			.sign = 's',					       \
+			.realbits = 24,					       \
+			.storagebits = 32,				       \
+			.endianness = IIO_BE,				   \
+		},								\
+	}
+
+#define AD777x_CHAN_NO_FILTER_S(index)					       \
+	AD777x_CHAN_S(index, NULL)
+
+#define AD777x_CHAN_FILTER_S(index)					       \
+	AD777x_CHAN_S(index, ad7779_ext_filter)
+static const struct iio_chan_spec ad7779_channels[] = {
+	AD777x_CHAN_NO_FILTER_S(0),
+	AD777x_CHAN_NO_FILTER_S(1),
+	AD777x_CHAN_NO_FILTER_S(2),
+	AD777x_CHAN_NO_FILTER_S(3),
+	AD777x_CHAN_NO_FILTER_S(4),
+	AD777x_CHAN_NO_FILTER_S(5),
+	AD777x_CHAN_NO_FILTER_S(6),
+	AD777x_CHAN_NO_FILTER_S(7),
+	IIO_CHAN_SOFT_TIMESTAMP(8),
+};
+
+static const struct iio_chan_spec ad7779_channels_filter[] = {
+	AD777x_CHAN_FILTER_S(0),
+	AD777x_CHAN_FILTER_S(1),
+	AD777x_CHAN_FILTER_S(2),
+	AD777x_CHAN_FILTER_S(3),
+	AD777x_CHAN_FILTER_S(4),
+	AD777x_CHAN_FILTER_S(5),
+	AD777x_CHAN_FILTER_S(6),
+	AD777x_CHAN_FILTER_S(7),
+	IIO_CHAN_SOFT_TIMESTAMP(8),
+};
+
+static const struct iio_buffer_setup_ops ad7779_buffer_setup_ops = {
+	.preenable = ad7779_buffer_preenable,
+	.postdisable = ad7779_buffer_postdisable,
+};
+
+static const struct iio_trigger_ops ad7779_trigger_ops = {
+	.validate_device = iio_trigger_validate_own_device,
+};
+
+static int ad7779_powerup(struct ad7779_state *st, struct gpio_desc *start_gpio)
+{
+	int ret;
+
+	ret = ad7779_spi_write_mask(st, AD7779_REG_GEN_ERR_REG_1_EN,
+				    AD7779_SPI_CRC_EN_MSK,
+				    FIELD_PREP(AD7779_SPI_CRC_EN_MSK, 1));
+	if (ret)
+		return ret;
+
+	ret = ad7779_spi_write_mask(st, AD7779_REG_GENERAL_USER_CONFIG_1,
+				    AD7779_USRMOD_INIT_MSK,
+				    FIELD_PREP(AD7779_USRMOD_INIT_MSK, 5));
+	if (ret)
+		return ret;
+
+	ret = ad7779_spi_write_mask(st, AD7779_REG_DOUT_FORMAT,
+				    AD7779_DCLK_CLK_DIV_MSK,
+				    FIELD_PREP(AD7779_DCLK_CLK_DIV_MSK, 1));
+	if (ret)
+		return ret;
+
+	ret = ad7779_spi_write_mask(st, AD7779_REG_ADC_MUX_CONFIG,
+				    AD7779_REFMUX_CTRL_MSK,
+				    FIELD_PREP(AD7779_REFMUX_CTRL_MSK, 1));
+	if (ret)
+		return ret;
+
+	ret = ad7779_set_sampling_frequency(st, AD7779_DEFAULT_SAMPLING_FREQ);
+	if (ret)
+		return ret;
+
+	gpiod_set_value(start_gpio, 0);
+	/* Start setup time */
+	fsleep(15);
+	gpiod_set_value(start_gpio, 1);
+	fsleep(15);
+	gpiod_set_value(start_gpio, 0);
+	fsleep(15);
+
+	return 0;
+}
+
+static int ad7779_probe(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev;
+	struct ad7779_state *st;
+	struct gpio_desc *reset_gpio, *start_gpio;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+
+	st->mclk = devm_clk_get_enabled(&spi->dev, "mclk");
+	if (IS_ERR(st->mclk))
+		return PTR_ERR(st->mclk);
+
+	if (!spi->irq)
+		return dev_err_probe(&spi->dev, ret,
+				     "DRDY irq not present\n");
+
+	reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(reset_gpio))
+		return PTR_ERR(reset_gpio);
+
+	start_gpio = devm_gpiod_get(&spi->dev, "start", GPIOD_OUT_HIGH);
+	if (IS_ERR(start_gpio))
+		return PTR_ERR(start_gpio);
+
+	crc8_populate_msb(ad7779_crc8_table, AD7779_CRC8_POLY);
+	st->spi = spi;
+
+	st->chip_info = spi_get_device_match_data(spi);
+	if (!st->chip_info)
+		return -ENODEV;
+
+	ret = ad7779_reset(indio_dev, reset_gpio);
+	if (ret)
+		return ret;
+
+	ad7779_powerup(st, start_gpio);
+	if (ret)
+		return ret;
+
+	indio_dev->name = st->chip_info->name;
+	indio_dev->info = &ad7779_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = st->chip_info->channels;
+	indio_dev->num_channels = ARRAY_SIZE(ad7779_channels);
+
+	st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d",
+					  indio_dev->name, iio_device_id(indio_dev));
+	if (!st->trig)
+		return -ENOMEM;
+
+	st->trig->ops = &ad7779_trigger_ops;
+
+	iio_trigger_set_drvdata(st->trig, st);
+
+	ret = devm_request_irq(&spi->dev, spi->irq,
+			      iio_trigger_generic_data_rdy_poll,
+			      IRQF_ONESHOT | IRQF_NO_AUTOEN,
+			      indio_dev->name, st->trig);
+	if (ret)
+		return dev_err_probe(&spi->dev, ret, "request irq %d failed\n",
+				     st->spi->irq);
+
+	ret = devm_iio_trigger_register(&spi->dev, st->trig);
+	if (ret)
+		return ret;
+
+	indio_dev->trig = iio_trigger_get(st->trig);
+
+	init_completion(&st->completion);
+
+	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
+					      &iio_pollfunc_store_time,
+					      &ad7779_trigger_handler,
+					      &ad7779_buffer_setup_ops);
+	if (ret)
+		return ret;
+
+	ret = ad7779_spi_write_mask(st, AD7779_REG_DOUT_FORMAT,
+				    AD7779_DCLK_CLK_DIV_MSK,
+				    FIELD_PREP(AD7779_DCLK_CLK_DIV_MSK, 7));
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static int ad7779_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad7779_state *st = iio_priv(indio_dev);
+	int ret;
+
+	ret = ad7779_spi_write_mask(st, AD7779_REG_GENERAL_USER_CONFIG_1,
+				    AD7779_MOD_POWERMODE_MSK,
+				    FIELD_PREP(AD7779_MOD_POWERMODE_MSK,
+					       AD7779_LOW_POWER));
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int ad7779_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad7779_state *st = iio_priv(indio_dev);
+	int ret;
+
+	ret = ad7779_spi_write_mask(st, AD7779_REG_GENERAL_USER_CONFIG_1,
+				    AD7779_MOD_POWERMODE_MSK,
+				    FIELD_PREP(AD7779_MOD_POWERMODE_MSK,
+					       AD7779_HIGH_POWER));
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(ad7779_pm_ops, ad7779_suspend, ad7779_resume);
+
+static const struct ad7779_chip_info ad7770_chip_info = {
+	.name = "ad7770",
+	.channels = ad7779_channels,
+};
+
+static const struct ad7779_chip_info ad7771_chip_info = {
+	.name = "ad7771",
+	.channels = ad7779_channels_filter,
+};
+
+static const struct ad7779_chip_info ad7779_chip_info = {
+	.name = "ad7779",
+	.channels = ad7779_channels,
+};
+
+static const struct spi_device_id ad7779_id[] = {
+	{
+		.name = "ad7770",
+		.driver_data = (kernel_ulong_t)&ad7770_chip_info
+	},
+	{
+		.name = "ad7771",
+		.driver_data = (kernel_ulong_t)&ad7771_chip_info
+	},
+	{
+		.name = "ad7779",
+		.driver_data = (kernel_ulong_t)&ad7779_chip_info
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, ad7779_id);
+
+static const struct of_device_id ad7779_of_table[] = {
+	{
+		.compatible = "adi,ad7770",
+		.data = &ad7770_chip_info,
+	},
+	{
+		.compatible = "adi,ad7771",
+		.data = &ad7771_chip_info,
+	},
+	{
+		.compatible = "adi,ad7779",
+		.data = &ad7779_chip_info,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ad7779_of_table);
+
+static struct spi_driver ad7779_driver = {
+	.driver = {
+		.name = "ad7779",
+		.pm = pm_sleep_ptr(&ad7779_pm_ops),
+		.of_match_table = ad7779_of_table,
+	},
+	.probe = ad7779_probe,
+	.id_table = ad7779_id,
+};
+module_spi_driver(ad7779_driver);
+
+MODULE_AUTHOR("Ramona Alexandra Nechita <ramona.nechita@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD7779 ADC");
+MODULE_LICENSE("GPL");
-- 
2.43.0

Re: [PATCH v5 1/3] dt-bindings: iio: adc: add a7779 doc

[Rob Herring (Arm)]

On Thu, 12 Sep 2024 15:15:45 +0300, Ramona Alexandra Nechita wrote:
> Add dt bindings for AD7779 8-channel, simultaneous sampling ADC
> family with eight full Σ-Δ ADCs on chip and ultra-low input
> current to allow direct sensor connection.
> 
> Signed-off-by: Ramona Alexandra Nechita <ramona.nechita@analog.com>
> ---
>  .../bindings/iio/adc/adi,ad7779.yaml          | 84 +++++++++++++++++++
>  1 file changed, 84 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,ad7779.yaml
> 

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,ad7779.example.dtb: adc@0: Unevaluated properties are not allowed ('vref-supply' was unexpected)
	from schema $id: http://devicetree.org/schemas/iio/adc/adi,ad7779.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/iio/adc/adi,ad7779.example.dtb: adc@0: 'oneOf' conditional failed, one must be fixed:
	'interrupts' is a required property
	'interrupts-extended' is a required property
	from schema $id: http://devicetree.org/schemas/iio/adc/adi,ad7779.yaml#

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20240912121609.13438-2-ramona.nechita@analog.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 v5 2/3] Documentation: ABI: added filter mode doc in sysfs-bus-iio

[Andy Shevchenko]

On Thu, Sep 12, 2024 at 3:17 PM Ramona Alexandra Nechita
<ramona.nechita@analog.com> wrote:
>
> The filter mode / filter type property is used for ad4130
> and ad7779 drivers, therefore the ABI doc file for ad4130
> was removed, merging both of them in the sysfs-bus-iio.

...

> +What:          /sys/bus/iio/devices/iio:deviceX/filter_type_available
> +What:          /sys/bus/iio/devices/iio:deviceX/in_voltage-voltage_filter_mode_available
> +KernelVersion: 6.1

I believe I have already commented on this. The commit message keeps
silent about version changes. Why?

> +Contact:       linux-iio@vger.kernel.org
> +Description:
> +               Reading returns a list with the possible filter modes. Options
> +               for the attribute:
> +                       * "sinc3"       - The digital sinc3 filter. Moderate 1st conversion time.
> +                   Good noise performance.
> +                       * "sinc4"       - Sinc 4. Excellent noise performance. Long
> +                       1st conversion time.
> +                       * "sinc5"       - The digital sinc5 filter. Excellent noise performance
> +                       * "sinc4+sinc1" - Sinc4 + averaging by 8. Low 1st conversion
> +                   time.
> +                       * "sinc3+rej60" - Sinc3 + 60Hz rejection.
> +                       * "sinc3+sinc1" - Sinc3 + averaging by 8. Low 1st conversion
> +                   time.
> +                       * "sinc3+pf1"   - Sinc3 + device specific Post Filter 1.
> +                       * "sinc3+pf2"   - Sinc3 + device specific Post Filter 2.
> +                       * "sinc3+pf3"   - Sinc3 + device specific Post Filter 3.
> +                       * "sinc3+pf4"   - Sinc3 + device specific Post Filter 4.

Also, the original file was more verbose for the complex cases, like
"sinc3+pfX", why has this been changed?

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v5 3/3] drivers: iio: adc: add support for ad777x family

[Andy Shevchenko]

On Thu, Sep 12, 2024 at 3:17 PM Ramona Alexandra Nechita
<ramona.nechita@analog.com> wrote:
>
> Add support for AD7770, AD7771, AD7779 ADCs. The device is capable of

"..., and AD7779..."

> sending out data both on DOUT lines interface,as on the SDO line.
> The driver currently implements only the SDO data streaming mode. SPI
> communication is used alternatively for accessing registers and streaming
> data. Register access are protected by crc8.

accesses

...

> +/*
> + * AD7770, AD7771, AD7779 ADC

"..., and AD7779..."

> + *
> + * Copyright 2023-2024 Analog Devices Inc.
> + */

...

> +#define AD7779_MAXCLK_LOWPOWER                 4096000

Units? _HZ? _uV?

...

> +#define GAIN_REL                               0x555555

Is it something like making value for 12 channels? Can you elaborate a
bit (perhaps in the comment)?

...

> +struct ad7779_state {
> +       struct spi_device *spi;
> +       const struct ad7779_chip_info *chip_info;
> +       struct clk *mclk;
> +       struct iio_trigger *trig;
> +       struct completion completion;
> +       unsigned int sampling_freq;
> +       enum ad7779_filter filter_enabled;
> +       /*
> +        * DMA (thus cache coherency maintenance) requires the
> +        * transfer buffers to live in their own cache lines.
> +        */
> +       u8                      reg_rx_buf[3] __aligned(IIO_DMA_MINALIGN);
> +       u8                      reg_tx_buf[3];
> +       u32                     spidata_rx[8];
> +       u32                     spidata_tx[8];
> +       u8                      reset_buf[8];
> +};

Have you run `pahole` to check if this can be optimised in size?

...

> +static int ad7779_spi_read(struct ad7779_state *st, u8 reg, u8 *rbuf)
> +{
> +       int ret;
> +       int length = 3;
> +       u8 crc_buf[2];
> +       u8 exp_crc = 0;
> +       struct spi_transfer reg_read_tr[] = {
> +               {
> +                       .tx_buf = st->reg_tx_buf,
> +                       .rx_buf = st->reg_rx_buf,
> +               },
> +       };
> +
> +       if (reg == AD7779_REG_GEN_ERR_REG_1_EN)
> +               length = 2;

Does it mean the crc byte will be ignored? If so, why do we even
bother to spend resources on calculating it in that case? Same Q for
other similar cases.

> +       reg_read_tr[0].len = length;
> +
> +       st->reg_tx_buf[0] = AD7779_SPI_READ_CMD | FIELD_GET(AD7779_REG_MSK, reg);
> +       st->reg_tx_buf[1] = 0;
> +       st->reg_tx_buf[2] = crc8(ad7779_crc8_table, st->reg_tx_buf, 2, 0);
> +
> +       ret = spi_sync_transfer(st->spi, reg_read_tr, ARRAY_SIZE(reg_read_tr));
> +       if (ret)
> +               return ret;
> +
> +       crc_buf[0] = AD7779_SPI_READ_CMD | FIELD_GET(AD7779_REG_MSK, reg);
> +       crc_buf[1] = st->reg_rx_buf[1];
> +       exp_crc = crc8(ad7779_crc8_table, crc_buf, 2, 0);
> +       if (reg != AD7779_REG_GEN_ERR_REG_1_EN && exp_crc != st->reg_rx_buf[2]) {
> +               dev_err(&st->spi->dev, "Bad CRC %x, expected %x",
> +                       st->reg_rx_buf[2], exp_crc);
> +               return -EINVAL;
> +       }
> +       *rbuf = st->reg_rx_buf[1];
> +
> +       return 0;
> +}

...

> +       regval = data;
> +       regval &= ~mask;
> +       regval |= val;

Traditional pattern is to have this as

    regval = (data & ~mask) | (val & mask);

...

> +static int ad7779_set_sampling_frequency(struct ad7779_state *st,
> +                                        unsigned int sampling_freq)
> +{
> +       int ret;
> +       unsigned int dec;
> +       unsigned int div;
> +       unsigned int decimal;
> +       int temp;
> +       unsigned int kfreq;

freq_khz will be better name

> +       if (st->filter_enabled == AD7779_SINC3 &&
> +           sampling_freq > AD7779_SINC3_MAXFREQ)
> +               return -EINVAL;
> +
> +       if (st->filter_enabled == AD7779_SINC5 &&
> +           sampling_freq > AD7779_SINC5_MAXFREQ)
> +               return -EINVAL;
> +
> +       if (sampling_freq > AD7779_SPIMODE_MAX_SAMP_FREQ)
> +               return -EINVAL;
> +
> +       div = AD7779_HIGHPOWER_DIV;
> +
> +       kfreq = sampling_freq / KILO;
> +       dec = div / kfreq;
> +
> +       ret = ad7779_spi_write(st, AD7779_REG_SRC_N_MSB,
> +                              FIELD_GET(AD7779_FREQ_MSB_MSK, dec));
> +       if (ret)
> +               return ret;
> +       ret = ad7779_spi_write(st, AD7779_REG_SRC_N_LSB,
> +                              FIELD_GET(AD7779_FREQ_LSB_MSK, dec));
> +       if (ret)
> +               return ret;

> +       if (div % kfreq) {

It's better to combine with / above, because some ISAs may have a
single assembly instruction to do both at the same time. I'm not sure
compiler (os some versions of it) may see this.

  dec = div / freq_khz;
  frac = div % freq_khz;
  ...
  if (frac) {
      ...
  }

> +               temp = (div * KILO) / kfreq;
> +               decimal = ((temp -  dec * KILO) << 16) / KILO;

I would add a small comment to show the formula behind this.

> +               ret = ad7779_spi_write(st, AD7779_REG_SRC_N_MSB,
> +                                      FIELD_GET(AD7779_FREQ_MSB_MSK, decimal));
> +               if (ret)
> +                       return ret;
> +               ret = ad7779_spi_write(st, AD7779_REG_SRC_N_LSB,
> +                                      FIELD_GET(AD7779_FREQ_LSB_MSK, decimal));
> +               if (ret)
> +                       return ret;
> +       } else {
> +               ret = ad7779_spi_write(st, AD7779_REG_SRC_N_MSB,
> +                                      FIELD_GET(AD7779_FREQ_MSB_MSK, 0x0));
> +               if (ret)
> +                       return ret;
> +               ret = ad7779_spi_write(st, AD7779_REG_SRC_N_LSB,
> +                                      FIELD_GET(AD7779_FREQ_LSB_MSK, 0x0));
> +               if (ret)
> +                       return ret;
> +       }
> +       ret = ad7779_spi_write(st, AD7779_REG_SRC_UPDATE, 0x1);
> +       if (ret)
> +               return ret;
> +
> +       /* SRC update settling time */
> +       fsleep(15);

+ Blank line, otherwise it's unclear how fsleep() is applied (or to
which sections).

> +       ret = ad7779_spi_write(st, AD7779_REG_SRC_UPDATE, 0x0);
> +       if (ret)
> +               return ret;
> +
> +       /* SRC update settling time */
> +       fsleep(15);

Alternatively make a helper to avoid potential desynchronisation in
the code pieces

statuc int ad7779_update_src(..., val)
{
    ...
    /* ... */
    fsleep(...);

    return 0;
}

> +       st->sampling_freq = sampling_freq;
> +
> +       return 0;
> +}

...

> +static int ad7779_set_calibscale(struct ad7779_state *st, int channel, int val)
> +{
> +       int ret;
> +       unsigned int gain;
> +       unsigned long long tmp;
> +       u8 gain_bytes[3];
> +
> +       tmp = val * 5592405LL;
> +       gain = DIV_ROUND_CLOSEST_ULL(tmp, MEGA);

Formula to be explained?
Magic number to be described (in the same comment), please?

> +       put_unaligned_be24(gain, gain_bytes);
> +       ret = ad7779_spi_write(st,
> +                              AD7779_REG_CH_GAIN_UPPER_BYTE(channel),
> +                              gain_bytes[0]);
> +       if (ret)
> +               return ret;
> +
> +       ret = ad7779_spi_write(st,
> +                              AD7779_REG_CH_GAIN_MID_BYTE(channel),
> +                              gain_bytes[1]);
> +       if (ret)
> +               return ret;
> +
> +       return ad7779_spi_write(st,
> +                               AD7779_REG_CH_GAIN_LOWER_BYTE(channel),
> +                               gain_bytes[2]);
> +}

...

> +       iio_device_claim_direct_scoped(return -EBUSY, indio_dev) {
> +               switch (mask) {
> +               case IIO_CHAN_INFO_CALIBSCALE:
> +                       *val = ad7779_get_calibscale(st, chan->channel);
> +                       if (*val < 0)
> +                               return -EINVAL;
> +                       *val2 = GAIN_REL;
> +                       return IIO_VAL_FRACTIONAL;
> +               case IIO_CHAN_INFO_CALIBBIAS:
> +                       *val = ad7779_get_calibbias(st, chan->channel);
> +                       if (*val < 0)
> +                               return -EINVAL;
> +                       return IIO_VAL_INT;
> +               case IIO_CHAN_INFO_SAMP_FREQ:
> +                       *val = st->sampling_freq;
> +                       if (*val < 0)
> +                               return -EINVAL;
> +                       return IIO_VAL_INT;
> +               }
> +               return -EINVAL;
> +       }

> +       unreachable();

Hmm... Is it necessary? Same Q for other similar cases. I.o.w. what
will be if we don't add this line?

> +}

...

> +static irqreturn_t ad7779_trigger_handler(int irq, void *p)
> +{
> +       struct iio_poll_func *pf = p;
> +       struct iio_dev *indio_dev = pf->indio_dev;
> +       struct ad7779_state *st = iio_priv(indio_dev);
> +       int ret;
> +       int bit;
> +       int k = 0;
> +       /*
> +        * Each channel shifts out HEADER + 24 bits of data therefore 8 * u32
> +        * for the data and 64 bits for the timestamp
> +        */

May you do the respective structure and use aligned_s64 for the timestamp?

> +       u32 tmp[10];
> +
> +       struct spi_transfer sd_readback_tr[] = {
> +               {
> +                       .rx_buf = st->spidata_rx,
> +                       .tx_buf = st->spidata_tx,
> +                       .len = AD7779_NUM_CHANNELS * AD7779_CHAN_DATA_SIZE,
> +               }
> +       };
> +
> +       if (!iio_buffer_enabled(indio_dev))
> +               goto exit_handler;
> +
> +       st->spidata_tx[0] = AD7779_SPI_READ_CMD;
> +       ret = spi_sync_transfer(st->spi, sd_readback_tr,
> +                               ARRAY_SIZE(sd_readback_tr));
> +       if (ret) {
> +               dev_err(&st->spi->dev,
> +                       "spi transfer error in irq handler");
> +               goto exit_handler;
> +       }
> +
> +       for_each_set_bit(bit, indio_dev->active_scan_mask, AD7779_NUM_CHANNELS - 1)
> +               tmp[k++] = st->spidata_rx[bit];
> +
> +       iio_push_to_buffers_with_timestamp(indio_dev, &tmp[0], pf->timestamp);
> +
> +exit_handler:
> +       iio_trigger_notify_done(indio_dev->trig);
> +       return IRQ_HANDLED;
> +}

...

> +       st->mclk = devm_clk_get_enabled(&spi->dev, "mclk");
> +       if (IS_ERR(st->mclk))
> +               return PTR_ERR(st->mclk);

> +       if (!spi->irq)
> +               return dev_err_probe(&spi->dev, ret,
> +                                    "DRDY irq not present\n");

This can be done much earlier and avoid unneeded resource allocations.

...

> +static int ad7779_suspend(struct device *dev)
> +{
> +       struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +       struct ad7779_state *st = iio_priv(indio_dev);
> +       int ret;
> +
> +       ret = ad7779_spi_write_mask(st, AD7779_REG_GENERAL_USER_CONFIG_1,
> +                                   AD7779_MOD_POWERMODE_MSK,
> +                                   FIELD_PREP(AD7779_MOD_POWERMODE_MSK,
> +                                              AD7779_LOW_POWER));
> +       if (ret)
> +               return ret;
> +
> +       return 0;

  return ad7779_spi_write_mask(...);

> +}
> +
> +static int ad7779_resume(struct device *dev)
> +{
> +       struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +       struct ad7779_state *st = iio_priv(indio_dev);
> +       int ret;
> +
> +       ret = ad7779_spi_write_mask(st, AD7779_REG_GENERAL_USER_CONFIG_1,
> +                                   AD7779_MOD_POWERMODE_MSK,
> +                                   FIELD_PREP(AD7779_MOD_POWERMODE_MSK,
> +                                              AD7779_HIGH_POWER));
> +       if (ret)
> +               return ret;
> +
> +       return 0;

Ditto.

> +}

...

> +static const struct spi_device_id ad7779_id[] = {
> +       {
> +               .name = "ad7770",
> +               .driver_data = (kernel_ulong_t)&ad7770_chip_info

Leave trailing comma.

> +       },
> +       {
> +               .name = "ad7771",
> +               .driver_data = (kernel_ulong_t)&ad7771_chip_info

Ditto.

> +       },
> +       {
> +               .name = "ad7779",
> +               .driver_data = (kernel_ulong_t)&ad7779_chip_info

Ditto.

> +       },
> +       { }
> +};

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v5 2/3] Documentation: ABI: added filter mode doc in sysfs-bus-iio

[kernel test robot]

Hi Ramona,

kernel test robot noticed the following build warnings:

[auto build test WARNING on jic23-iio/togreg]
[also build test WARNING on robh/for-next linus/master v6.11-rc7 next-20240912]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Ramona-Alexandra-Nechita/dt-bindings-iio-adc-add-a7779-doc/20240912-201936
base:   https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git togreg
patch link:    https://lore.kernel.org/r/20240912121609.13438-3-ramona.nechita%40analog.com
patch subject: [PATCH v5 2/3] Documentation: ABI: added filter mode doc in sysfs-bus-iio
reproduce: (https://download.01.org/0day-ci/archive/20240913/202409131243.olYA3Qdt-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202409131243.olYA3Qdt-lkp@intel.com/

All warnings (new ones prefixed by >>):

   Warning: Documentation/devicetree/bindings/power/wakeup-source.txt references a file that doesn't exist: Documentation/devicetree/bindings/input/qcom,pm8xxx-keypad.txt
   Warning: Documentation/devicetree/bindings/regulator/siliconmitus,sm5703-regulator.yaml references a file that doesn't exist: Documentation/devicetree/bindings/mfd/siliconmitus,sm5703.yaml
   Warning: Documentation/hwmon/g762.rst references a file that doesn't exist: Documentation/devicetree/bindings/hwmon/g762.txt
>> Warning: MAINTAINERS references a file that doesn't exist: Documentation/ABI/testing/sysfs-bus-iio-adc-ad4130
   Warning: MAINTAINERS references a file that doesn't exist: Documentation/devicetree/bindings/reserved-memory/qcom
   Warning: MAINTAINERS references a file that doesn't exist: Documentation/devicetree/bindings/display/exynos/
   Warning: MAINTAINERS references a file that doesn't exist: Documentation/devicetree/bindings/misc/fsl,qoriq-mc.txt
   Warning: MAINTAINERS references a file that doesn't exist: Documentation/devicetree/bindings/nvmem/u-boot,env.yaml
   Using alabaster theme

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

RE: [PATCH v5 2/3] Documentation: ABI: added filter mode doc in sysfs-bus-iio

[Nechita, Ramona]

>>
>> The filter mode / filter type property is used for ad4130 and ad7779 
>> drivers, therefore the ABI doc file for ad4130 was removed, merging 
>> both of them in the sysfs-bus-iio.
>
>...
>
>> +What:          /sys/bus/iio/devices/iio:deviceX/filter_type_available
>> +What:          /sys/bus/iio/devices/iio:deviceX/in_voltage-voltage_filter_mode_available
>> +KernelVersion: 6.1
>
>I believe I have already commented on this. The commit message keeps silent about version changes. Why?

I mentioned it in the cover-letter, since the attributes of two devices were merged, and one of them was available in 6.1 ad the other in 6.2, it felt appropriate to leave it as 6.1.
I was wondering if this is ok or if it should be kept as 6.2. Should this be mentioned in the commit message as well?

>
>> +Contact:       linux-iio@vger.kernel.org
>> +Description:
>> +               Reading returns a list with the possible filter modes. Options
>> +               for the attribute:
>> +                       * "sinc3"       - The digital sinc3 filter. Moderate 1st conversion time.
>> +                   Good noise performance.
>> +                       * "sinc4"       - Sinc 4. Excellent noise performance. Long
>> +                       1st conversion time.
>> +                       * "sinc5"       - The digital sinc5 filter. Excellent noise performance
>> +                       * "sinc4+sinc1" - Sinc4 + averaging by 8. Low 1st conversion
>> +                   time.
>> +                       * "sinc3+rej60" - Sinc3 + 60Hz rejection.
>> +                       * "sinc3+sinc1" - Sinc3 + averaging by 8. Low 1st conversion
>> +                   time.
>> +                       * "sinc3+pf1"   - Sinc3 + device specific Post Filter 1.
>> +                       * "sinc3+pf2"   - Sinc3 + device specific Post Filter 2.
>> +                       * "sinc3+pf3"   - Sinc3 + device specific Post Filter 3.
>> +                       * "sinc3+pf4"   - Sinc3 + device specific Post Filter 4.
>
>Also, the original file was more verbose for the complex cases, like "sinc3+pfX", why has this been changed?

Since this is a more generic file I was advised to leave out specific details, should I include them just as they were in the original file?


--
Best Regards,
Ramona

Re: [PATCH v5 2/3] Documentation: ABI: added filter mode doc in sysfs-bus-iio

[Andy Shevchenko]

On Fri, Sep 13, 2024 at 02:06:48PM +0000, Nechita, Ramona wrote:
> >>
> >> The filter mode / filter type property is used for ad4130 and ad7779
> >> drivers, therefore the ABI doc file for ad4130 was removed, merging
> >> both of them in the sysfs-bus-iio.

...

> >> +What:          /sys/bus/iio/devices/iio:deviceX/filter_type_available
> >> +What:          /sys/bus/iio/devices/iio:deviceX/in_voltage-voltage_filter_mode_available
> >> +KernelVersion: 6.1
> >
> >I believe I have already commented on this. The commit message keeps silent about version changes. Why?
> 
> I mentioned it in the cover-letter, since the attributes of two devices were
> merged, and one of them was available in 6.1 ad the other in 6.2, it felt
> appropriate to leave it as 6.1.
> I was wondering if this is ok or if it should be kept as 6.2. Should this be
> mentioned in the commit message as well?

Please, mention in the commit message.

> >> +Contact:       linux-iio@vger.kernel.org
> >> +Description:
> >> +               Reading returns a list with the possible filter modes. Options
> >> +               for the attribute:
> >> +                       * "sinc3"       - The digital sinc3 filter. Moderate 1st conversion time.
> >> +                   Good noise performance.
> >> +                       * "sinc4"       - Sinc 4. Excellent noise performance. Long
> >> +                       1st conversion time.
> >> +                       * "sinc5"       - The digital sinc5 filter. Excellent noise performance
> >> +                       * "sinc4+sinc1" - Sinc4 + averaging by 8. Low 1st conversion
> >> +                   time.
> >> +                       * "sinc3+rej60" - Sinc3 + 60Hz rejection.
> >> +                       * "sinc3+sinc1" - Sinc3 + averaging by 8. Low 1st conversion
> >> +                   time.
> >> +                       * "sinc3+pf1"   - Sinc3 + device specific Post Filter 1.
> >> +                       * "sinc3+pf2"   - Sinc3 + device specific Post Filter 2.
> >> +                       * "sinc3+pf3"   - Sinc3 + device specific Post Filter 3.
> >> +                       * "sinc3+pf4"   - Sinc3 + device specific Post Filter 4.
> >
> >Also, the original file was more verbose for the complex cases, like
> >"sinc3+pfX", why has this been changed?
> 
> Since this is a more generic file I was advised to leave out specific
> details, should I include them just as they were in the original file?

I would leave the examples for the mentioned chip in the parentheses. But it's
up to Jonathan, I have no such device anyway, so personally I'm not affected
:-)

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v5 3/3] drivers: iio: adc: add support for ad777x family

[kernel test robot]

Hi Ramona,

kernel test robot noticed the following build warnings:

[auto build test WARNING on jic23-iio/togreg]
[also build test WARNING on robh/for-next linus/master v6.11-rc7 next-20240913]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Ramona-Alexandra-Nechita/dt-bindings-iio-adc-add-a7779-doc/20240912-201936
base:   https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git togreg
patch link:    https://lore.kernel.org/r/20240912121609.13438-4-ramona.nechita%40analog.com
patch subject: [PATCH v5 3/3] drivers: iio: adc: add support for ad777x family
config: hexagon-allmodconfig (https://download.01.org/0day-ci/archive/20240914/202409140955.bz1rH7Q6-lkp@intel.com/config)
compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project bf684034844c660b778f0eba103582f582b710c9)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240914/202409140955.bz1rH7Q6-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202409140955.bz1rH7Q6-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from drivers/iio/adc/ad7779.c:15:
   In file included from include/linux/interrupt.h:11:
   In file included from include/linux/hardirq.h:11:
   In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
   In file included from include/asm-generic/hardirq.h:17:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:14:
   In file included from arch/hexagon/include/asm/io.h:328:
   include/asm-generic/io.h:548:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     548 |         val = __raw_readb(PCI_IOBASE + addr);
         |                           ~~~~~~~~~~ ^
   include/asm-generic/io.h:561:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     561 |         val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
         |                                                         ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu'
      37 | #define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
         |                                                   ^
   In file included from drivers/iio/adc/ad7779.c:15:
   In file included from include/linux/interrupt.h:11:
   In file included from include/linux/hardirq.h:11:
   In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
   In file included from include/asm-generic/hardirq.h:17:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:14:
   In file included from arch/hexagon/include/asm/io.h:328:
   include/asm-generic/io.h:574:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     574 |         val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
         |                                                         ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu'
      35 | #define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
         |                                                   ^
   In file included from drivers/iio/adc/ad7779.c:15:
   In file included from include/linux/interrupt.h:11:
   In file included from include/linux/hardirq.h:11:
   In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
   In file included from include/asm-generic/hardirq.h:17:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:14:
   In file included from arch/hexagon/include/asm/io.h:328:
   include/asm-generic/io.h:585:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     585 |         __raw_writeb(value, PCI_IOBASE + addr);
         |                             ~~~~~~~~~~ ^
   include/asm-generic/io.h:595:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     595 |         __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
         |                                                       ~~~~~~~~~~ ^
   include/asm-generic/io.h:605:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     605 |         __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
         |                                                       ~~~~~~~~~~ ^
   In file included from drivers/iio/adc/ad7779.c:19:
   In file included from include/linux/regulator/consumer.h:35:
   In file included from include/linux/suspend.h:5:
   In file included from include/linux/swap.h:9:
   In file included from include/linux/memcontrol.h:21:
   In file included from include/linux/mm.h:2232:
   include/linux/vmstat.h:517:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
     517 |         return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
         |                               ~~~~~~~~~~~ ^ ~~~
>> drivers/iio/adc/ad7779.c:748:35: warning: variable 'ret' is uninitialized when used here [-Wuninitialized]
     748 |                 return dev_err_probe(&spi->dev, ret,
         |                                                 ^~~
   drivers/iio/adc/ad7779.c:735:9: note: initialize the variable 'ret' to silence this warning
     735 |         int ret;
         |                ^
         |                 = 0
   8 warnings generated.


vim +/ret +748 drivers/iio/adc/ad7779.c

   729	
   730	static int ad7779_probe(struct spi_device *spi)
   731	{
   732		struct iio_dev *indio_dev;
   733		struct ad7779_state *st;
   734		struct gpio_desc *reset_gpio, *start_gpio;
   735		int ret;
   736	
   737		indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
   738		if (!indio_dev)
   739			return -ENOMEM;
   740	
   741		st = iio_priv(indio_dev);
   742	
   743		st->mclk = devm_clk_get_enabled(&spi->dev, "mclk");
   744		if (IS_ERR(st->mclk))
   745			return PTR_ERR(st->mclk);
   746	
   747		if (!spi->irq)
 > 748			return dev_err_probe(&spi->dev, ret,
   749					     "DRDY irq not present\n");
   750	
   751		reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset", GPIOD_OUT_LOW);
   752		if (IS_ERR(reset_gpio))
   753			return PTR_ERR(reset_gpio);
   754	
   755		start_gpio = devm_gpiod_get(&spi->dev, "start", GPIOD_OUT_HIGH);
   756		if (IS_ERR(start_gpio))
   757			return PTR_ERR(start_gpio);
   758	
   759		crc8_populate_msb(ad7779_crc8_table, AD7779_CRC8_POLY);
   760		st->spi = spi;
   761	
   762		st->chip_info = spi_get_device_match_data(spi);
   763		if (!st->chip_info)
   764			return -ENODEV;
   765	
   766		ret = ad7779_reset(indio_dev, reset_gpio);
   767		if (ret)
   768			return ret;
   769	
   770		ad7779_powerup(st, start_gpio);
   771		if (ret)
   772			return ret;
   773	
   774		indio_dev->name = st->chip_info->name;
   775		indio_dev->info = &ad7779_info;
   776		indio_dev->modes = INDIO_DIRECT_MODE;
   777		indio_dev->channels = st->chip_info->channels;
   778		indio_dev->num_channels = ARRAY_SIZE(ad7779_channels);
   779	
   780		st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d",
   781						  indio_dev->name, iio_device_id(indio_dev));
   782		if (!st->trig)
   783			return -ENOMEM;
   784	
   785		st->trig->ops = &ad7779_trigger_ops;
   786	
   787		iio_trigger_set_drvdata(st->trig, st);
   788	
   789		ret = devm_request_irq(&spi->dev, spi->irq,
   790				      iio_trigger_generic_data_rdy_poll,
   791				      IRQF_ONESHOT | IRQF_NO_AUTOEN,
   792				      indio_dev->name, st->trig);
   793		if (ret)
   794			return dev_err_probe(&spi->dev, ret, "request irq %d failed\n",
   795					     st->spi->irq);
   796	
   797		ret = devm_iio_trigger_register(&spi->dev, st->trig);
   798		if (ret)
   799			return ret;
   800	
   801		indio_dev->trig = iio_trigger_get(st->trig);
   802	
   803		init_completion(&st->completion);
   804	
   805		ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
   806						      &iio_pollfunc_store_time,
   807						      &ad7779_trigger_handler,
   808						      &ad7779_buffer_setup_ops);
   809		if (ret)
   810			return ret;
   811	
   812		ret = ad7779_spi_write_mask(st, AD7779_REG_DOUT_FORMAT,
   813					    AD7779_DCLK_CLK_DIV_MSK,
   814					    FIELD_PREP(AD7779_DCLK_CLK_DIV_MSK, 7));
   815		if (ret)
   816			return ret;
   817	
   818		return devm_iio_device_register(&spi->dev, indio_dev);
   819	}
   820	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH v5 1/3] dt-bindings: iio: adc: add a7779 doc

[Jonathan Cameron]

On Thu, 12 Sep 2024 15:15:45 +0300
Ramona Alexandra Nechita <ramona.nechita@analog.com> wrote:

> Add dt bindings for AD7779 8-channel, simultaneous sampling ADC
> family with eight full Σ-Δ ADCs on chip and ultra-low input
> current to allow direct sensor connection.
Typo in device name in the title

Also no need to say 'doc' when in dt-bindings.
dt-bindings: iio: adc: add adi,ad7779

> 
> Signed-off-by: Ramona Alexandra Nechita <ramona.nechita@analog.com>
> ---
>  .../bindings/iio/adc/adi,ad7779.yaml          | 84 +++++++++++++++++++
>  1 file changed, 84 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,ad7779.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7779.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7779.yaml
> new file mode 100644
> index 000000000000..0ed5ec5dd8fe
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7779.yaml
> @@ -0,0 +1,84 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/adc/adi,ad7779.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Analog Devices AD777X family 8-Channel, 24-Bit, Simultaneous Sampling ADCs
> +
> +maintainers:
> +  - Ramona Nechita <ramona.nechita@analog.com>
> +
> +description: |
> +  The AD777X family consist of 8-channel, simultaneous sampling analog-to-
> +  digital converter (ADC). Eight full Σ-Δ ADCs are on-chip. The
> +  AD7771 provides an ultralow input current to allow direct sensor
> +  connection. Each input channel has a programmable gain stage
> +  allowing gains of 1, 2, 4, and 8 to map lower amplitude sensor
> +  outputs into the full-scale ADC input range, maximizing the
> +  dynamic range of the signal chain.
> +
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/ad7770.pdf
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/ad7771.pdf
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/ad7779.pdf
> +
> +$ref: /schemas/spi/spi-peripheral-props.yaml#
> +
> +properties:
> +  compatible:
> +    enum:
> +      - adi,ad7770
> +      - adi,ad7771
> +      - adi,ad7779

No power in general?

All power supplies should be listed and if they need to have voltage
on them for the device to function they should be in the required list.

I left feedback on this and alert gpios in review of v4.
Please address that as well for v6.



> +
> +  reg:
> +    maxItems: 1
> +
> +  '#address-cells':
> +    const: 1
> +
> +  '#size-cells':
> +    const: 0
> +
> +  clocks:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +    description:
> +      Interrupt line for DRDY signal which indicates the end of conversion
> +      independently of the interface selected to read back the Σ-∆ conversion.
> +
> +  start-gpios:
> +    description:
> +      Pin that controls start synchronization pulse.
> +    maxItems: 1
> +
> +  reset-gpios:
> +    maxItems: 1
> +
> +required:
> +  - compatible
> +  - reg
> +  - clocks
> +  - interrupts
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/gpio/gpio.h>
> +    spi {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        adc@0 {
> +          compatible = "adi,ad7779";
> +          reg = <0>;
> +          vref-supply = <&vref>;
> +          start-gpios = <&gpio0 87 GPIO_ACTIVE_LOW>;
> +          reset-gpios = <&gpio0 93 GPIO_ACTIVE_LOW>;
> +          clocks = <&adc_clk>;
> +        };
> +    };
> +...

Re: [PATCH v5 2/3] Documentation: ABI: added filter mode doc in sysfs-bus-iio

[Jonathan Cameron]

On Fri, 13 Sep 2024 20:36:32 +0300
Andy Shevchenko <andy.shevchenko@gmail.com> wrote:

> On Fri, Sep 13, 2024 at 02:06:48PM +0000, Nechita, Ramona wrote:
> > >>
> > >> The filter mode / filter type property is used for ad4130 and ad7779
> > >> drivers, therefore the ABI doc file for ad4130 was removed, merging
> > >> both of them in the sysfs-bus-iio.  
> 
> ...
> 
> > >> +What:          /sys/bus/iio/devices/iio:deviceX/filter_type_available
> > >> +What:          /sys/bus/iio/devices/iio:deviceX/in_voltage-voltage_filter_mode_available
> > >> +KernelVersion: 6.1  
> > >
> > >I believe I have already commented on this. The commit message keeps silent about version changes. Why?  
> > 
> > I mentioned it in the cover-letter, since the attributes of two devices were
> > merged, and one of them was available in 6.1 ad the other in 6.2, it felt
> > appropriate to leave it as 6.1.
> > I was wondering if this is ok or if it should be kept as 6.2. Should this be
> > mentioned in the commit message as well?  
> 
> Please, mention in the commit message.
> 
> > >> +Contact:       linux-iio@vger.kernel.org
> > >> +Description:
> > >> +               Reading returns a list with the possible filter modes. Options
> > >> +               for the attribute:
> > >> +                       * "sinc3"       - The digital sinc3 filter. Moderate 1st conversion time.
> > >> +                   Good noise performance.
> > >> +                       * "sinc4"       - Sinc 4. Excellent noise performance. Long
> > >> +                       1st conversion time.
> > >> +                       * "sinc5"       - The digital sinc5 filter. Excellent noise performance
> > >> +                       * "sinc4+sinc1" - Sinc4 + averaging by 8. Low 1st conversion
> > >> +                   time.
> > >> +                       * "sinc3+rej60" - Sinc3 + 60Hz rejection.
> > >> +                       * "sinc3+sinc1" - Sinc3 + averaging by 8. Low 1st conversion
> > >> +                   time.
> > >> +                       * "sinc3+pf1"   - Sinc3 + device specific Post Filter 1.
> > >> +                       * "sinc3+pf2"   - Sinc3 + device specific Post Filter 2.
> > >> +                       * "sinc3+pf3"   - Sinc3 + device specific Post Filter 3.
> > >> +                       * "sinc3+pf4"   - Sinc3 + device specific Post Filter 4.  
> > >
> > >Also, the original file was more verbose for the complex cases, like
> > >"sinc3+pfX", why has this been changed?  
> > 
> > Since this is a more generic file I was advised to leave out specific
> > details, should I include them just as they were in the original file?  
> 
> I would leave the examples for the mentioned chip in the parentheses. But it's
> up to Jonathan, I have no such device anyway, so personally I'm not affected
> :-)

It gets tricky as we gain more and more devices.  Nice to have that data somewhere, but
maybe a device specific document is more appropriate than keeping it in here?
(i.e. not in the ABI docs, but in general IIO per device documentation similar to the
 docs added recently for various other ADI parts).

Jonathan

> 

Re: [PATCH v5 2/3] Documentation: ABI: added filter mode doc in sysfs-bus-iio

[Jonathan Cameron]

On Fri, 13 Sep 2024 12:16:34 +0800
kernel test robot <lkp@intel.com> wrote:

> Hi Ramona,
> 
> kernel test robot noticed the following build warnings:
> 
> [auto build test WARNING on jic23-iio/togreg]
> [also build test WARNING on robh/for-next linus/master v6.11-rc7 next-20240912]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Ramona-Alexandra-Nechita/dt-bindings-iio-adc-add-a7779-doc/20240912-201936
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git togreg
> patch link:    https://lore.kernel.org/r/20240912121609.13438-3-ramona.nechita%40analog.com
> patch subject: [PATCH v5 2/3] Documentation: ABI: added filter mode doc in sysfs-bus-iio
> reproduce: (https://download.01.org/0day-ci/archive/20240913/202409131243.olYA3Qdt-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202409131243.olYA3Qdt-lkp@intel.com/
> 
> All warnings (new ones prefixed by >>):
> 
>    Warning: Documentation/devicetree/bindings/power/wakeup-source.txt references a file that doesn't exist: Documentation/devicetree/bindings/input/qcom,pm8xxx-keypad.txt
>    Warning: Documentation/devicetree/bindings/regulator/siliconmitus,sm5703-regulator.yaml references a file that doesn't exist: Documentation/devicetree/bindings/mfd/siliconmitus,sm5703.yaml
>    Warning: Documentation/hwmon/g762.rst references a file that doesn't exist: Documentation/devicetree/bindings/hwmon/g762.txt
> >> Warning: MAINTAINERS references a file that doesn't exist: Documentation/ABI/testing/sysfs-bus-iio-adc-ad4130  
Ah. Ramona, make sure to delete this reference as well in this patch.

Thanks,

Jonathan

>    Warning: MAINTAINERS references a file that doesn't exist: Documentation/devicetree/bindings/reserved-memory/qcom
>    Warning: MAINTAINERS references a file that doesn't exist: Documentation/devicetree/bindings/display/exynos/
>    Warning: MAINTAINERS references a file that doesn't exist: Documentation/devicetree/bindings/misc/fsl,qoriq-mc.txt
>    Warning: MAINTAINERS references a file that doesn't exist: Documentation/devicetree/bindings/nvmem/u-boot,env.yaml
>    Using alabaster theme
> 

Re: [PATCH v5 3/3] drivers: iio: adc: add support for ad777x family

[Jonathan Cameron]

> ...
> 
> > +       iio_device_claim_direct_scoped(return -EBUSY, indio_dev) {
> > +               switch (mask) {
> > +               case IIO_CHAN_INFO_CALIBSCALE:
> > +                       *val = ad7779_get_calibscale(st, chan->channel);
> > +                       if (*val < 0)
> > +                               return -EINVAL;
> > +                       *val2 = GAIN_REL;
> > +                       return IIO_VAL_FRACTIONAL;
> > +               case IIO_CHAN_INFO_CALIBBIAS:
> > +                       *val = ad7779_get_calibbias(st, chan->channel);
> > +                       if (*val < 0)
> > +                               return -EINVAL;
> > +                       return IIO_VAL_INT;
> > +               case IIO_CHAN_INFO_SAMP_FREQ:
> > +                       *val = st->sampling_freq;
> > +                       if (*val < 0)
> > +                               return -EINVAL;
> > +                       return IIO_VAL_INT;
> > +               }
> > +               return -EINVAL;
> > +       }  
> 
> > +       unreachable();  
> 
> Hmm... Is it necessary? Same Q for other similar cases. I.o.w. what
> will be if we don't add this line?

The compiler can't tell that the contents of iio_device_claim_direct_scoped()
always runs.  Hence normal result is it complains that nothing was returned.

Why the compiler can't figure out?  Who knows... 

Jonathan

Re: [PATCH v5 3/3] drivers: iio: adc: add support for ad777x family

[Jonathan Cameron]

skip "nr_"
>          |                               ~~~~~~~~~~~ ^ ~~~
> >> drivers/iio/adc/ad7779.c:748:35: warning: variable 'ret' is uninitialized when used here [-Wuninitialized]  
>      748 |                 return dev_err_probe(&spi->dev, ret,
>          |                                                 ^~~
>    drivers/iio/adc/ad7779.c:735:9: note: initialize the variable 'ret' to silence this warning
>      735 |         int ret;
>          |                ^
>          |                 = 0
Definitely don't do that!

just replace ret with -EINVAL

Jonathan

>    8 warnings generated.
> 
> 
> vim +/ret +748 drivers/iio/adc/ad7779.c
> 
>    729	
>    730	static int ad7779_probe(struct spi_device *spi)
>    731	{
>    732		struct iio_dev *indio_dev;
>    733		struct ad7779_state *st;
>    734		struct gpio_desc *reset_gpio, *start_gpio;
>    735		int ret;
>    736	
>    737		indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
>    738		if (!indio_dev)
>    739			return -ENOMEM;
>    740	
>    741		st = iio_priv(indio_dev);
>    742	
>    743		st->mclk = devm_clk_get_enabled(&spi->dev, "mclk");
>    744		if (IS_ERR(st->mclk))
>    745			return PTR_ERR(st->mclk);
>    746	
>    747		if (!spi->irq)
>  > 748			return dev_err_probe(&spi->dev, ret,  
>    749					     "DRDY irq not present\n");
>    750	

Re: [PATCH v5 3/3] drivers: iio: adc: add support for ad777x family

[Jonathan Cameron]

On Thu, 12 Sep 2024 15:15:47 +0300
Ramona Alexandra Nechita <ramona.nechita@analog.com> wrote:

> Add support for AD7770, AD7771, AD7779 ADCs. The device is capable of
> sending out data both on DOUT lines interface,as on the SDO line.
> The driver currently implements only the SDO data streaming mode. SPI
> communication is used alternatively for accessing registers and streaming
> data. Register access are protected by crc8.
> 
> Signed-off-by: Ramona Alexandra Nechita <ramona.nechita@analog.com>
Hi Ramona,

A few additional comments inline,

Jonathan
> diff --git a/drivers/iio/adc/ad7779.c b/drivers/iio/adc/ad7779.c
> new file mode 100644
> index 000000000000..05ae72257c9e
> --- /dev/null
> +++ b/drivers/iio/adc/ad7779.c
> @@ -0,0 +1,917 @@

> +static int ad7779_set_calibbias(struct ad7779_state *st, int channel, int val)
> +{
> +	int ret;
> +	u8 calibbias[3];
> +
> +	put_unaligned_be24(val, calibbias);
> +	ret = ad7779_spi_write(st,
> +			       AD7779_REG_CH_OFFSET_UPPER_BYTE(channel),
> +			       calibbias[0]);
> +	if (ret)
> +		return ret;
> +
> +	ret = ad7779_spi_write(st,
> +			       AD7779_REG_CH_OFFSET_MID_BYTE(channel),
> +			       calibbias[1]);
> +	if (ret)
> +		return ret;
> +
> +	return ad7779_spi_write(st,
> +				AD7779_REG_CH_OFFSET_LOWER_BYTE(channel),
Wrap closer to 80 chars.
	return ad7779_spi_write(st, AD7779_REG_CH_OFFSET_LOWER_BYTE(channel),
				calibbias[2]);

etc as it'll shorted the code a little bit for no significant loss
of readability.  Do the same for all other such cases.
> +}

> +
> +static irqreturn_t ad7779_trigger_handler(int irq, void *p)
> +{
> +	struct iio_poll_func *pf = p;
> +	struct iio_dev *indio_dev = pf->indio_dev;
> +	struct ad7779_state *st = iio_priv(indio_dev);
> +	int ret;
> +	int bit;
> +	int k = 0;
> +	/*
> +	 * Each channel shifts out HEADER + 24 bits of data therefore 8 * u32
> +	 * for the data and 64 bits for the timestamp
> +	 */
> +	u32 tmp[10];
> +
> +	struct spi_transfer sd_readback_tr[] = {
> +		{
> +			.rx_buf = st->spidata_rx,
> +			.tx_buf = st->spidata_tx,
> +			.len = AD7779_NUM_CHANNELS * AD7779_CHAN_DATA_SIZE,
> +		}
> +	};
> +
> +	if (!iio_buffer_enabled(indio_dev))
> +		goto exit_handler;

If buffers aren't enabled, the push to buffers won't do anything. So this race
shouldn't matter.  If it does, what happens?
I'm curious because I'd expect any races that cause trouble in this case
to be pretty universal across drivers.


> +
> +	st->spidata_tx[0] = AD7779_SPI_READ_CMD;
> +	ret = spi_sync_transfer(st->spi, sd_readback_tr,
> +				ARRAY_SIZE(sd_readback_tr));
> +	if (ret) {
> +		dev_err(&st->spi->dev,
> +			"spi transfer error in irq handler");
> +		goto exit_handler;
> +	}
> +
> +	for_each_set_bit(bit, indio_dev->active_scan_mask, AD7779_NUM_CHANNELS - 1)
> +		tmp[k++] = st->spidata_rx[bit];

If you can't use the core demux handling + available_scan_masks, please add
a comment here to say why.  That would allow you to do the SPI transfer directly
into the buffer you then push below. The IIO core will figure out how to
pull data out of that if the user wants a subset of channels.


> +
> +	iio_push_to_buffers_with_timestamp(indio_dev, &tmp[0], pf->timestamp);
> +
> +exit_handler:
> +	iio_trigger_notify_done(indio_dev->trig);
> +	return IRQ_HANDLED;
> +}
> +
> +static int ad7779_reset(struct iio_dev *indio_dev, struct gpio_desc *reset_gpio)
> +{
> +	struct ad7779_state *st = iio_priv(indio_dev);
> +	int ret;
> +	struct spi_transfer reg_read_tr[] = {
> +		{
> +			.tx_buf = st->reset_buf,
> +			.len = 8,
> +		},
> +	};
> +
> +	memset(st->reset_buf, 0xff, sizeof(st->reset_buf));
> +
> +	if (reset_gpio) {
> +		/* Delay for reset to occur is 225 microseconds*/
> +		gpiod_set_value(reset_gpio, 1);
> +		fsleep(230);
> +		return 0;

 +	}
	if (reset_gpio) {
		/* Delay for reset to occur is 225 microseconds*/
		gpiod_set_value(reset_gpio, 1);

	} else {
		struct spi_transfer reg_read_tr[] = {
			{
				.tx_buf = st->reset_buf,
				.len = 8,
			},
		};
		int ret;

		memset(st->reset_buf, 0xff, sizeof(st->reset_buf));
		ret = spi_sync_transfer(st->spi, reg_read_tr,
					ARRAY_SIZE(reg_read_tr));
		if (ret)
			return ret;
	}
	fsleep(230);
	return 0;

or something along those lines.  Shares the sleep so showing the wait
is the same in both types of reset and doesn't do a memset that I think
is otherwise irrelevant if there is a gpio.
> +
> +	ret = spi_sync_transfer(st->spi, reg_read_tr,
> +				ARRAY_SIZE(reg_read_tr));
> +	if (ret)
> +		return ret;
> +
> +	/* Delay for reset to occur is 225 microseconds*/
> +	fsleep(230);
> +
> +	return 0;
> +}

> +static int ad7779_probe(struct spi_device *spi)
> +{
> +	struct iio_dev *indio_dev;
> +	struct ad7779_state *st;
> +	struct gpio_desc *reset_gpio, *start_gpio;
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	st = iio_priv(indio_dev);
> +
> +	st->mclk = devm_clk_get_enabled(&spi->dev, "mclk");
> +	if (IS_ERR(st->mclk))
> +		return PTR_ERR(st->mclk);
> +
> +	if (!spi->irq)
> +		return dev_err_probe(&spi->dev, ret,
> +				     "DRDY irq not present\n");
> +
> +	reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset", GPIOD_OUT_LOW);
> +	if (IS_ERR(reset_gpio))
> +		return PTR_ERR(reset_gpio);
> +
> +	start_gpio = devm_gpiod_get(&spi->dev, "start", GPIOD_OUT_HIGH);
> +	if (IS_ERR(start_gpio))
> +		return PTR_ERR(start_gpio);
> +
> +	crc8_populate_msb(ad7779_crc8_table, AD7779_CRC8_POLY);
> +	st->spi = spi;
> +
> +	st->chip_info = spi_get_device_match_data(spi);
> +	if (!st->chip_info)
> +		return -ENODEV;
> +
> +	ret = ad7779_reset(indio_dev, reset_gpio);
> +	if (ret)
> +		return ret;
> +
> +	ad7779_powerup(st, start_gpio);
> +	if (ret)
> +		return ret;
What powers the device down again if we hit an error?

Probably need a devm_add_action_or_reset() or if it self powers down
may a comment on that.

> +
> +	indio_dev->name = st->chip_info->name;
> +	indio_dev->info = &ad7779_info;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->channels = st->chip_info->channels;
> +	indio_dev->num_channels = ARRAY_SIZE(ad7779_channels);
> +
> +	st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d",
> +					  indio_dev->name, iio_device_id(indio_dev));
> +	if (!st->trig)
> +		return -ENOMEM;
> +
> +	st->trig->ops = &ad7779_trigger_ops;
> +
> +	iio_trigger_set_drvdata(st->trig, st);
> +
> +	ret = devm_request_irq(&spi->dev, spi->irq,
> +			      iio_trigger_generic_data_rdy_poll,
> +			      IRQF_ONESHOT | IRQF_NO_AUTOEN,
> +			      indio_dev->name, st->trig);
> +	if (ret)
> +		return dev_err_probe(&spi->dev, ret, "request irq %d failed\n",
> +				     st->spi->irq);
> +
> +	ret = devm_iio_trigger_register(&spi->dev, st->trig);
> +	if (ret)
> +		return ret;
> +
> +	indio_dev->trig = iio_trigger_get(st->trig);
> +
> +	init_completion(&st->completion);
> +
> +	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
> +					      &iio_pollfunc_store_time,
> +					      &ad7779_trigger_handler,
> +					      &ad7779_buffer_setup_ops);
> +	if (ret)
> +		return ret;
> +
> +	ret = ad7779_spi_write_mask(st, AD7779_REG_DOUT_FORMAT,
> +				    AD7779_DCLK_CLK_DIV_MSK,
> +				    FIELD_PREP(AD7779_DCLK_CLK_DIV_MSK, 7));
> +	if (ret)
> +		return ret;
> +
> +	return devm_iio_device_register(&spi->dev, indio_dev);
> +}
> +
> +static int ad7779_suspend(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct ad7779_state *st = iio_priv(indio_dev);
> +	int ret;
> +
> +	ret = ad7779_spi_write_mask(st, AD7779_REG_GENERAL_USER_CONFIG_1,
> +				    AD7779_MOD_POWERMODE_MSK,
> +				    FIELD_PREP(AD7779_MOD_POWERMODE_MSK,
> +					       AD7779_LOW_POWER));
> +	if (ret)
> +		return ret;
As below.  Given if !ret, ret == 0 so same as just returning it unconditionally.


> +
> +	return 0;
> +}
> +
> +static int ad7779_resume(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct ad7779_state *st = iio_priv(indio_dev);
> +	int ret;
> +
> +	ret = ad7779_spi_write_mask(st, AD7779_REG_GENERAL_USER_CONFIG_1,
> +				    AD7779_MOD_POWERMODE_MSK,
> +				    FIELD_PREP(AD7779_MOD_POWERMODE_MSK,
> +					       AD7779_HIGH_POWER));
> +	if (ret)
> +		return ret;
	return ad7779_spi_write_mask...

> +
> +	return 0;
> +}

RE: [PATCH v5 3/3] drivers: iio: adc: add support for ad777x family

[Nechita, Ramona]

Hello all,

Just a minor question
...
>
>> +
>> +static irqreturn_t ad7779_trigger_handler(int irq, void *p) {
>> +	struct iio_poll_func *pf = p;
>> +	struct iio_dev *indio_dev = pf->indio_dev;
>> +	struct ad7779_state *st = iio_priv(indio_dev);
>> +	int ret;
>> +	int bit;
>> +	int k = 0;
>> +	/*
>> +	 * Each channel shifts out HEADER + 24 bits of data therefore 8 * u32
>> +	 * for the data and 64 bits for the timestamp
>> +	 */
>> +	u32 tmp[10];
>> +
>> +	struct spi_transfer sd_readback_tr[] = {
>> +		{
>> +			.rx_buf = st->spidata_rx,
>> +			.tx_buf = st->spidata_tx,
>> +			.len = AD7779_NUM_CHANNELS * AD7779_CHAN_DATA_SIZE,
>> +		}
>> +	};
>> +
>> +	if (!iio_buffer_enabled(indio_dev))
>> +		goto exit_handler;
>
>If buffers aren't enabled, the push to buffers won't do anything. So this race shouldn't matter.  If it does, what happens?
>I'm curious because I'd expect any races that cause trouble in this case to be pretty universal across drivers.

I added that condition rather because the DRDY pulse will keep on being generated even when the buffers are not active,
and it would be better to exit the function sooner. I tested it and it does not break to remove the condition, I just
thought it made more sense like this. Should I delete it?

>....

Best regards,
Ramona Nechita

Re: [PATCH v5 3/3] drivers: iio: adc: add support for ad777x family

[David Lechner]

On Fri, Sep 20, 2024 at 3:24 PM Nechita, Ramona
<Ramona.Nechita@analog.com> wrote:
>
> Hello all,
>
> Just a minor question
> ...
> >
> >> +
> >> +static irqreturn_t ad7779_trigger_handler(int irq, void *p) {
> >> +    struct iio_poll_func *pf = p;
> >> +    struct iio_dev *indio_dev = pf->indio_dev;
> >> +    struct ad7779_state *st = iio_priv(indio_dev);
> >> +    int ret;
> >> +    int bit;
> >> +    int k = 0;
> >> +    /*
> >> +     * Each channel shifts out HEADER + 24 bits of data therefore 8 * u32
> >> +     * for the data and 64 bits for the timestamp
> >> +     */
> >> +    u32 tmp[10];
> >> +
> >> +    struct spi_transfer sd_readback_tr[] = {
> >> +            {
> >> +                    .rx_buf = st->spidata_rx,
> >> +                    .tx_buf = st->spidata_tx,
> >> +                    .len = AD7779_NUM_CHANNELS * AD7779_CHAN_DATA_SIZE,
> >> +            }
> >> +    };
> >> +
> >> +    if (!iio_buffer_enabled(indio_dev))
> >> +            goto exit_handler;
> >
> >If buffers aren't enabled, the push to buffers won't do anything. So this race shouldn't matter.  If it does, what happens?
> >I'm curious because I'd expect any races that cause trouble in this case to be pretty universal across drivers.
>
> I added that condition rather because the DRDY pulse will keep on being generated even when the buffers are not active,
> and it would be better to exit the function sooner. I tested it and it does not break to remove the condition, I just
> thought it made more sense like this. Should I delete it?
>
> >....
>
> Best regards,
> Ramona Nechita
>
>

Perhaps a better way to handle this would be to move

    disable_irq(st->spi->irq);

to the buffer predisable callback instead of doing it in the buffer
postdisable callback. Then we will be sure to not get any more DRDY
interrupts after the buffer is disabled.

(And to keep things balanced, moved the corresponding irq_enable() to
the buffer postenable callback.)

Since ad7779_trigger_handler is the IIO trigger interrupt handler and
not the DRDY interrupt handler though, it is already not possible for
this interrupt handler to be called while the IIO buffer is enabled.
So it should be safe to remove the if
(!iio_buffere_enabled(indio_dev)) even without the other changes I
suggested.

RE: [PATCH v5 3/3] drivers: iio: adc: add support for ad777x family

[Nechita, Ramona]

Hello all,

There is another thing that I forgot to mention inline with my last email.

> Add support for AD7770, AD7771, AD7779 ADCs. The device is capable of 
> sending out data both on DOUT lines interface,as on the SDO line.
> The driver currently implements only the SDO data streaming mode. SPI 
> communication is used alternatively for accessing registers and 
> streaming data. Register access are protected by crc8.
> 
> Signed-off-by: Ramona Alexandra Nechita <ramona.nechita@analog.com>
Hi Ramona,

....

>> +static int ad7779_probe(struct spi_device *spi) {
>> +	struct iio_dev *indio_dev;
>> +	struct ad7779_state *st;
>> +	struct gpio_desc *reset_gpio, *start_gpio;
>> +	int ret;
>> +
>> +	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
>> +	if (!indio_dev)
>> +		return -ENOMEM;
>> +
>> +	st = iio_priv(indio_dev);
>> +
>> +	st->mclk = devm_clk_get_enabled(&spi->dev, "mclk");
>> +	if (IS_ERR(st->mclk))
>> +		return PTR_ERR(st->mclk);
>> +
>> +	if (!spi->irq)
>> +		return dev_err_probe(&spi->dev, ret,
>> +				     "DRDY irq not present\n");
>> +
>> +	reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset", GPIOD_OUT_LOW);
>> +	if (IS_ERR(reset_gpio))
>> +		return PTR_ERR(reset_gpio);
>> +
>> +	start_gpio = devm_gpiod_get(&spi->dev, "start", GPIOD_OUT_HIGH);
>> +	if (IS_ERR(start_gpio))
>> +		return PTR_ERR(start_gpio);
>> +
>> +	crc8_populate_msb(ad7779_crc8_table, AD7779_CRC8_POLY);
>> +	st->spi = spi;
>> +
>> +	st->chip_info = spi_get_device_match_data(spi);
>> +	if (!st->chip_info)
>> +		return -ENODEV;
>> +
>> +	ret = ad7779_reset(indio_dev, reset_gpio);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ad7779_powerup(st, start_gpio);
>> +	if (ret)
>> +		return ret;
>What powers the device down again if we hit an error?
>
>Probably need a devm_add_action_or_reset() or if it self powers down may a comment on that.

In the powerup function there are only some register writes and the start gpio is only a synchronization pulse (perhaps the name powerup is not very appropriate), 
would an action or reset be necessary in this case? Since the regulators are not used in the driver, should there be a function disabling them anyway?


Best Regards,
Ramona

Re: [PATCH v5 3/3] drivers: iio: adc: add support for ad777x family

[Jonathan Cameron]

On Mon, 23 Sep 2024 14:51:28 +0200
David Lechner <dlechner@baylibre.com> wrote:

> On Fri, Sep 20, 2024 at 3:24 PM Nechita, Ramona
> <Ramona.Nechita@analog.com> wrote:
> >
> > Hello all,
> >
> > Just a minor question
> > ...  
> > >  
> > >> +
> > >> +static irqreturn_t ad7779_trigger_handler(int irq, void *p) {
> > >> +    struct iio_poll_func *pf = p;
> > >> +    struct iio_dev *indio_dev = pf->indio_dev;
> > >> +    struct ad7779_state *st = iio_priv(indio_dev);
> > >> +    int ret;
> > >> +    int bit;
> > >> +    int k = 0;
> > >> +    /*
> > >> +     * Each channel shifts out HEADER + 24 bits of data therefore 8 * u32
> > >> +     * for the data and 64 bits for the timestamp
> > >> +     */
> > >> +    u32 tmp[10];
> > >> +
> > >> +    struct spi_transfer sd_readback_tr[] = {
> > >> +            {
> > >> +                    .rx_buf = st->spidata_rx,
> > >> +                    .tx_buf = st->spidata_tx,
> > >> +                    .len = AD7779_NUM_CHANNELS * AD7779_CHAN_DATA_SIZE,
> > >> +            }
> > >> +    };
> > >> +
> > >> +    if (!iio_buffer_enabled(indio_dev))
> > >> +            goto exit_handler;  
> > >
> > >If buffers aren't enabled, the push to buffers won't do anything. So this race shouldn't matter.  If it does, what happens?
> > >I'm curious because I'd expect any races that cause trouble in this case to be pretty universal across drivers.  
> >
> > I added that condition rather because the DRDY pulse will keep on being generated even when the buffers are not active,
> > and it would be better to exit the function sooner. I tested it and it does not break to remove the condition, I just
> > thought it made more sense like this. Should I delete it?
> >  
> > >....  
> >
> > Best regards,
> > Ramona Nechita
> >
> >  
> 
> Perhaps a better way to handle this would be to move
> 
>     disable_irq(st->spi->irq);
> 
> to the buffer predisable callback instead of doing it in the buffer
> postdisable callback. Then we will be sure to not get any more DRDY
> interrupts after the buffer is disabled.
> 
> (And to keep things balanced, moved the corresponding irq_enable() to
> the buffer postenable callback.)

That makes logical sense but in reality in the vast majority of cases
it makes no practical difference whether things are in the pre or
post callbacks as the fundamental races with tear down are there in
both cases but shouldn't matter as they correspond to slightly
earlier or later disabling of the buffer.  So this is a nice to
have for readabilty and understanding rather than a required change I think.

> 
> Since ad7779_trigger_handler is the IIO trigger interrupt handler and
> not the DRDY interrupt handler though, it is already not possible for
> this interrupt handler to be called while the IIO buffer is enabled.
> So it should be safe to remove the if
> (!iio_buffere_enabled(indio_dev)) even without the other changes I
> suggested.
Exactly.  

Jonathan

Re: [PATCH v5 3/3] drivers: iio: adc: add support for ad777x family

[Jonathan Cameron]

> >> +
> >> +	ret = ad7779_reset(indio_dev, reset_gpio);
> >> +	if (ret)
> >> +		return ret;
> >> +
> >> +	ad7779_powerup(st, start_gpio);
> >> +	if (ret)
> >> +		return ret;  
> >What powers the device down again if we hit an error?
> >
> >Probably need a devm_add_action_or_reset() or if it self powers down may a comment on that.  
> 
> In the powerup function there are only some register writes and the start gpio is only a synchronization pulse (perhaps the name powerup is not very appropriate), 
> would an action or reset be necessary in this case? Since the regulators are not used in the driver, should there be a function disabling them anyway?
> 
If there is nothing useful to do indeed not but when I see
a power up, I rather expect a power down.  Is there anything
that can do that or is it a case of it will go to sleep anyway
for some other reason?

Jonathan

> 
> Best Regards,
> Ramona
> 

RE: [PATCH v5 3/3] drivers: iio: adc: add support for ad777x family

[Nechita, Ramona]

Hello Jonathan,

>> >> +
>> >> +	ret = ad7779_reset(indio_dev, reset_gpio);
>> >> +	if (ret)
>> >> +		return ret;
>> >> +
>> >> +	ad7779_powerup(st, start_gpio);
>> >> +	if (ret)
>> >> +		return ret;
>> >What powers the device down again if we hit an error?
>> >
>> >Probably need a devm_add_action_or_reset() or if it self powers down may a comment on that.  
>> 
>> In the powerup function there are only some register writes and the 
>> start gpio is only a synchronization pulse (perhaps the name powerup is not very appropriate), would an action or reset be necessary in this case? Since the regulators are not used in the driver, should there be a function disabling them anyway?
>> 
>If there is nothing useful to do indeed not but when I see a power up, I rather expect a power down.  Is there anything that can do that or is it a case of it will go to sleep anyway for some other reason?

I don't think there would be anything to do in a powerdown function specifically, but I could rename the powerup function to "_config" or something similar, to make it more intuitive.

>
Best Regards,
Ramona

Re: [PATCH v5 3/3] drivers: iio: adc: add support for ad777x family

[Jonathan Cameron]

On Thu, 10 Oct 2024 14:35:52 +0000
"Nechita, Ramona" <Ramona.Nechita@analog.com> wrote:

> Hello Jonathan,
> 
> >> >> +
> >> >> +	ret = ad7779_reset(indio_dev, reset_gpio);
> >> >> +	if (ret)
> >> >> +		return ret;
> >> >> +
> >> >> +	ad7779_powerup(st, start_gpio);
> >> >> +	if (ret)
> >> >> +		return ret;  
> >> >What powers the device down again if we hit an error?
> >> >
> >> >Probably need a devm_add_action_or_reset() or if it self powers down may a comment on that.    
> >> 
> >> In the powerup function there are only some register writes and the 
> >> start gpio is only a synchronization pulse (perhaps the name powerup is not very appropriate), would an action or reset be necessary in this case? Since the regulators are not used in the driver, should there be a function disabling them anyway?
> >>   
> >If there is nothing useful to do indeed not but when I see a power up, I rather expect a power down.  Is there anything that can do that or is it a case of it will go to sleep anyway for some other reason?  
> 
> I don't think there would be anything to do in a powerdown function specifically, but I could rename the powerup function to "_config" or something similar, to make it more intuitive.
ok. That will at least make me less suspicious when I read this
after forgetting all about it ;)

thanks,

Jonathan

> 
> >  
> Best Regards,
> Ramona
> 
>