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

["Nuno Sá" <noname.nuno@gmail.com>]

On Wed, 2024-05-22 at 14:59 +0300, ranechita wrote:
> Added support for ad7770,ad7771,ad7779 ADCs. The
> data is streamed only on the spi-mode, without
> using the data lines.
> 
> Signed-off-by: ranechita <ramona.nechita@analog.com>
> ---
>  drivers/iio/adc/Kconfig  |   11 +
>  drivers/iio/adc/Makefile |    1 +
>  drivers/iio/adc/ad7779.c | 1182 ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 1194 insertions(+)
>  create mode 100644 drivers/iio/adc/ad7779.c
> 
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 0d9282fa67f5..3e42cbc365d7 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -206,6 +206,17 @@ 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 AD7779 SPI
> +	  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 b3c434722364..e25997e926bb 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -24,6 +24,7 @@ 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..d2c1b14464ff
> --- /dev/null
> +++ b/drivers/iio/adc/ad7779.c
> @@ -0,0 +1,1182 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * AD777X ADC
> + *
> + * Copyright 2023 Analog Devices Inc.
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/bitops.h>
> +#include <linux/clk.h>
> +#include <linux/crc8.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/gpio.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/module.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/spi/spi.h>
> +#include <linux/string.h>
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/kfifo_buf.h>
> +#include <linux/iio/sysfs.h>
> +
> +#include "cf_axi_adc.h"
> +
> +#define AD777X_SPI_READ_CMD			BIT(7)
> +
> +#define AD777X_DISABLE_SD			BIT(7)
> +
> +#define AD777X_REG_CH_DISABLE			0x08
> +#define AD777X_REG_CH_SYNC_OFFSET(ch)		(0x09 + (ch))
> +#define AD777X_REG_CH_CONFIG(ch)		(0x00 + (ch))
> +#define AD777X_REG_GENERAL_USER_CONFIG_1	0x11
> +#define AD777X_REG_GENERAL_USER_CONFIG_2	0x12
> +#define AD777X_REG_GENERAL_USER_CONFIG_3	0x13
> +#define AD777X_REG_DOUT_FORMAT			0x14
> +#define AD777X_REG_ADC_MUX_CONFIG		0x15
> +#define AD777X_REG_GPIO_CONFIG			0x17
> +#define AD777X_REG_BUFFER_CONFIG_1		0x19
> +#define AD777X_REG_GLOBAL_MUX_CONFIG		0x16
> +#define AD777X_REG_BUFFER_CONFIG_2		0x1A
> +#define AD777X_REG_GPIO_DATA			0x18
> +#define AD777X_REG_CH_OFFSET_UPPER_BYTE(ch)	(0x1C + (ch) * 6)
> +#define AD777X_REG_CH_OFFSET_LOWER_BYTE(ch)	(0x1E + (ch) * 6)
> +#define AD777X_REG_CH_GAIN_UPPER_BYTE(ch)	(0x1F + (ch) * 6)
> +#define AD777X_REG_CH_OFFSET_MID_BYTE(ch)	(0x1D + (ch) * 6)
> +#define AD777X_REG_CH_GAIN_MID_BYTE(ch)		(0x20 + (ch) * 6)
> +#define AD777X_REG_CH_ERR_REG(ch)		(0x4C + (ch))
> +#define AD777X_REG_CH0_1_SAT_ERR		0x54
> +#define AD777X_REG_CH_GAIN_LOWER_BYTE(ch)	(0x21 + (ch) * 6)
> +#define AD777X_REG_CH2_3_SAT_ERR		0x55
> +#define AD777X_REG_CH4_5_SAT_ERR		0x56
> +#define AD777X_REG_CH6_7_SAT_ERR		0x57
> +#define AD777X_REG_CHX_ERR_REG_EN		0x58
> +#define AD777X_REG_GEN_ERR_REG_1		0x59
> +#define AD777X_REG_GEN_ERR_REG_1_EN		0x5A
> +#define AD777X_REG_GEN_ERR_REG_2		0x5B
> +#define AD777X_REG_GEN_ERR_REG_2_EN		0x5C
> +#define AD777X_REG_STATUS_REG_1			0x5D
> +#define AD777X_REG_STATUS_REG_2			0x5E
> +#define AD777X_REG_STATUS_REG_3			0x5F
> +#define AD777X_REG_SRC_N_MSB			0x60
> +#define AD777X_REG_SRC_N_LSB			0x61
> +#define AD777X_REG_SRC_IF_MSB			0x62
> +#define AD777X_REG_SRC_IF_LSB			0x63
> +#define AD777X_REG_SRC_UPDATE			0x64
> +
> +#define AD777X_FILTER_MSK			BIT(6)
> +#define AD777X_MOD_POWERMODE_MSK		BIT(6)
> +#define AD777X_MOD_PDB_REFOUT_MSK		BIT(4)
> +#define AD777X_MOD_SPI_EN_MSK			BIT(4)
> +
> +/* AD777X_REG_DOUT_FORMAT */
> +#define AD777X_DOUT_FORMAT_MSK			GENMASK(7, 6)
> +#define AD777X_DOUT_HEADER_FORMAT		BIT(5)
> +#define AD777X_DCLK_CLK_DIV_MSK			GENMASK(3, 1)
> +
> +#define AD777X_REFMUX_CTRL_MSK			GENMASK(7, 6)
> +#define AD777X_SPI_CRC_EN_MSK			BIT(0)
> +
> +#define AD777X_MAXCLK_LOWPOWER			4096000
> +#define AD777X_NUM_CHANNELS			8
> +#define AD777X_RESET_BUF_SIZE			8
> +
> +#define AD777X_LOWPOWER_DIV			512
> +#define AD777X_HIGHPOWER_DIV			2048
> +
> +#define AD777X_SINC3_MAXFREQ			16000
> +#define AD777X_SINC5_MAXFREQ			128000
> +
> +#define AD777X_DEFAULT_SAMPLING_FREQ		8000
> +#define AD777X_DEFAULT_SAMPLING_2LINE		4000
> +#define AD777X_DEFAULT_SAMPLING_1LINE		2000
> +
> +#define AD777X_SPIMODE_MAX_SAMP_FREQ		16000
> +
> +/* AXI CONTROL REGS VALUES FOR DATA LINES */
> +#define AXI_CTRL_4_LINES			0x400
> +#define AXI_CTRL_2_LINES			0x200
> +#define AXI_CTRL_1_LINE				0x100
> +
> +#define DEC3					1000
> +#define DEC6					1000000
> +
> +#define GAIN_REL				0x555555
> +#define AD777X_FREQ_MSB_MSK			GENMASK(15, 8)
> +#define AD777X_FREQ_LSB_MSK			GENMASK(7, 0)
> +#define AD777X_UPPER				GENMASK(23, 16)
> +#define AD777X_MID				GENMASK(15, 8)
> +#define AD777X_LOWER				GENMASK(7, 0)
> +
> +#define AD777X_CRC8_POLY			0x07
> +DECLARE_CRC8_TABLE(ad777x_crc8_table);
> +
> +enum ad777x_data_lines {
> +	AD777x_4LINES,
> +	AD777x_2LINES,
> +	AD777x_1LINE,
> +};
> +
> +enum ad777x_filter {
> +	AD777X_SINC3,
> +	AD777X_SINC5,
> +};
> +
> +enum ad777x_variant {
> +	ad7770,
> +	ad7771,
> +	ad7779,
> +};
> +
> +enum ad777x_power_mode {
> +	AD777X_LOW_POWER,
> +	AD777X_HIGH_POWER,
> +};
> +
> +struct ad777x_chip_info {
> +	const char *name;
> +};
> +
> +struct ad777x_state {
> +	struct spi_device		*spi;
> +	const struct ad777x_chip_info	*chip_info;
> +	struct clk			*mclk;
> +	struct regulator		*vref;
> +	unsigned int			sampling_freq;
> +	enum ad777x_power_mode		power_mode;
> +	enum ad777x_data_lines		data_lines;
> +	enum ad777x_filter		filter_enabled;
> +	unsigned int			active_ch;
> +	unsigned int			spidata_mode;
> +	unsigned int			crc_enabled;
> +
> +	/*
> +	 * DMA (thus cache coherency maintenance) requires the
> +	 * transfer buffers to live in their own cache lines.
> +	 */
> +	u8			reg_rx_buf[3] ____cacheline_aligned;
> +	u8			reg_tx_buf[3];
> +	u8			spidata_rx[32];
> +	u8			spidata_tx[32];
> +	u8			reset_buf[8];
> +};
> +
> +static const char * const ad777x_filter_type[] = {
> +	[AD777X_SINC3] = "sinc3_filter",
> +	[AD777X_SINC5] = "sinc5_filter",
> +};
> +
> +static const char * const ad777x_data_lines_modes[] = {
> +	[AD777x_4LINES] = "4_data_lines",
> +	[AD777x_2LINES] = "2_data_lines",
> +	[AD777x_1LINE]  = "1_data_line",
> +};
> +
> +static bool ad777x_has_axi_adc(struct device *dev)
> +{
> +	return device_property_present(dev, "spibus-connected");
> +}
> +
> +static struct ad777x_state *ad777x_get_data(struct iio_dev *indio_dev)
> +{
> +	struct axiadc_converter *conv;
> +
> +	if (ad777x_has_axi_adc(&indio_dev->dev)) {
> +		conv = iio_device_get_drvdata(indio_dev);
> +		return conv->phy;
> +	}
> +
> +	return iio_priv(indio_dev);
> +}
> +

Hi Ramona,

Is this even compiling? This is definitely not code to be upstreamed since it relies
on the our out-of-tree/legacy driver for the adi-axi-adc. You need to convert this to
use the IIO backend framework (adding new interfaces if needed).

- Nuno Sá