iio:adc:ad7280a: Move out of staging

This is a rather unusual device (in IIO anyway).  However, it has
a near to standard userspace ABI.

Note the work to move this out of staging was done against a minimal
QEMU model, which doesn't model all the features of the device.
I have no intention to upstream the QEMU model as it was developed
just to enable this driver cleanup.

https://github.com/jic23/qemu/tree/ad7280a-hacks

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Link: https://lore.kernel.org/r/20220206190328.333093-21-jic23@kernel.org

3 files changed, 0 insertions, 1123 deletions

diff --git a/drivers/staging/iio/adc/Kconfig b/drivers/staging/iio/adc/Kconfig
index b25f41053fac..2f0d6cf048d2 100644
--- a/drivers/staging/iio/adc/Kconfig
+++ b/drivers/staging/iio/adc/Kconfig
@@ -15,15 +15,4 @@ config AD7816
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad7816.
 
-config AD7280
-	tristate "Analog Devices AD7280A Lithium Ion Battery Monitoring System"
-	depends on SPI
-	select CRC8
-	help
-	  Say yes here to build support for Analog Devices AD7280A
-	  Lithium Ion Battery Monitoring System.
-
-	  To compile this driver as a module, choose M here: the
-	  module will be called ad7280a
-
 endmenu
diff --git a/drivers/staging/iio/adc/Makefile b/drivers/staging/iio/adc/Makefile
index 6436a62b6278..1e2a94c4db84 100644
--- a/drivers/staging/iio/adc/Makefile
+++ b/drivers/staging/iio/adc/Makefile
@@ -4,4 +4,3 @@
 #
 
 obj-$(CONFIG_AD7816) += ad7816.o
-obj-$(CONFIG_AD7280) += ad7280a.o
diff --git a/drivers/staging/iio/adc/ad7280a.c b/drivers/staging/iio/adc/ad7280a.c
deleted file mode 100644
index ef9d27759961..000000000000
--- a/drivers/staging/iio/adc/ad7280a.c
+++ /dev/null
@@ -1,1111 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * AD7280A Lithium Ion Battery Monitoring System
- *
- * Copyright 2011 Analog Devices Inc.
- */
-
-#include <linux/bitfield.h>
-#include <linux/bits.h>
-#include <linux/crc8.h>
-#include <linux/delay.h>
-#include <linux/device.h>
-#include <linux/err.h>
-#include <linux/interrupt.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/mod_devicetable.h>
-#include <linux/mutex.h>
-#include <linux/slab.h>
-#include <linux/sysfs.h>
-#include <linux/spi/spi.h>
-
-#include <linux/iio/events.h>
-#include <linux/iio/iio.h>
-
-/* Registers */
-
-#define AD7280A_CELL_VOLTAGE_1_REG		0x0  /* D11 to D0, Read only */
-#define AD7280A_CELL_VOLTAGE_2_REG		0x1  /* D11 to D0, Read only */
-#define AD7280A_CELL_VOLTAGE_3_REG		0x2  /* D11 to D0, Read only */
-#define AD7280A_CELL_VOLTAGE_4_REG		0x3  /* D11 to D0, Read only */
-#define AD7280A_CELL_VOLTAGE_5_REG		0x4  /* D11 to D0, Read only */
-#define AD7280A_CELL_VOLTAGE_6_REG		0x5  /* D11 to D0, Read only */
-#define AD7280A_AUX_ADC_1_REG			0x6  /* D11 to D0, Read only */
-#define AD7280A_AUX_ADC_2_REG			0x7  /* D11 to D0, Read only */
-#define AD7280A_AUX_ADC_3_REG			0x8  /* D11 to D0, Read only */
-#define AD7280A_AUX_ADC_4_REG			0x9  /* D11 to D0, Read only */
-#define AD7280A_AUX_ADC_5_REG			0xA  /* D11 to D0, Read only */
-#define AD7280A_AUX_ADC_6_REG			0xB  /* D11 to D0, Read only */
-#define AD7280A_SELF_TEST_REG			0xC  /* D11 to D0, Read only */
-
-#define AD7280A_CTRL_HB_REG			0xD  /* D15 to D8, Read/write */
-#define   AD7280A_CTRL_HB_CONV_INPUT_MSK		GENMASK(7, 6)
-#define     AD7280A_CTRL_HB_CONV_INPUT_ALL			0
-#define     AD7280A_CTRL_HB_CONV_INPUT_6CELL_AUX1_3_5		1
-#define     AD7280A_CTRL_HB_CONV_INPUT_6CELL			2
-#define     AD7280A_CTRL_HB_CONV_INPUT_SELF_TEST		3
-#define   AD7280A_CTRL_HB_CONV_RREAD_MSK		GENMASK(5, 4)
-#define     AD7280A_CTRL_HB_CONV_RREAD_ALL			0
-#define     AD7280A_CTRL_HB_CONV_RREAD_6CELL_AUX1_3_5		1
-#define     AD7280A_CTRL_HB_CONV_RREAD_6CELL			2
-#define     AD7280A_CTRL_HB_CONV_RREAD_NO		        3
-#define   AD7280A_CTRL_HB_CONV_START_MSK		BIT(3)
-#define     AD7280A_CTRL_HB_CONV_START_CNVST			0
-#define     AD7280A_CTRL_HB_CONV_START_CS			1
-#define   AD7280A_CTRL_HB_CONV_AVG_MSK			GENMASK(2, 1)
-#define     AD7280A_CTRL_HB_CONV_AVG_DIS			0
-#define     AD7280A_CTRL_HB_CONV_AVG_2				1
-#define     AD7280A_CTRL_HB_CONV_AVG_4			        2
-#define     AD7280A_CTRL_HB_CONV_AVG_8			        3
-#define   AD7280A_CTRL_HB_PWRDN_SW			BIT(0)
-
-#define AD7280A_CTRL_LB_REG			0xE  /* D7 to D0, Read/write */
-#define   AD7280A_CTRL_LB_SWRST_MSK			BIT(7)
-#define   AD7280A_CTRL_LB_ACQ_TIME_MSK			GENMASK(6, 5)
-#define     AD7280A_CTRL_LB_ACQ_TIME_400ns			0
-#define     AD7280A_CTRL_LB_ACQ_TIME_800ns			1
-#define     AD7280A_CTRL_LB_ACQ_TIME_1200ns			2
-#define     AD7280A_CTRL_LB_ACQ_TIME_1600ns			3
-#define   AD7280A_CTRL_LB_MUST_SET			BIT(4)
-#define   AD7280A_CTRL_LB_THERMISTOR_MSK		BIT(3)
-#define   AD7280A_CTRL_LB_LOCK_DEV_ADDR_MSK		BIT(2)
-#define   AD7280A_CTRL_LB_INC_DEV_ADDR_MSK		BIT(1)
-#define   AD7280A_CTRL_LB_DAISY_CHAIN_RB_MSK		BIT(0)
-
-#define AD7280A_CELL_OVERVOLTAGE_REG		0xF  /* D7 to D0, Read/write */
-#define AD7280A_CELL_UNDERVOLTAGE_REG		0x10 /* D7 to D0, Read/write */
-#define AD7280A_AUX_ADC_OVERVOLTAGE_REG		0x11 /* D7 to D0, Read/write */
-#define AD7280A_AUX_ADC_UNDERVOLTAGE_REG	0x12 /* D7 to D0, Read/write */
-
-#define AD7280A_ALERT_REG			0x13 /* D7 to D0, Read/write */
-#define   AD7280A_ALERT_REMOVE_MSK			GENMASK(3, 0)
-#define     AD7280A_ALERT_REMOVE_AUX5			BIT(0)
-#define     AD7280A_ALERT_REMOVE_AUX3_AUX5		BIT(1)
-#define     AD7280A_ALERT_REMOVE_VIN5			BIT(2)
-#define     AD7280A_ALERT_REMOVE_VIN4_VIN5		BIT(3)
-#define   AD7280A_ALERT_GEN_STATIC_HIGH			BIT(6)
-#define   AD7280A_ALERT_RELAY_SIG_CHAIN_DOWN		(BIT(7) | BIT(6))
-
-#define AD7280A_CELL_BALANCE_REG		0x14 /* D7 to D0, Read/write */
-#define  AD7280A_CELL_BALANCE_CHAN_BITMAP_MSK		GENMASK(7, 2)
-#define AD7280A_CB1_TIMER_REG			0x15 /* D7 to D0, Read/write */
-#define  AD7280A_CB_TIMER_VAL_MSK			GENMASK(7, 3)
-#define AD7280A_CB2_TIMER_REG			0x16 /* D7 to D0, Read/write */
-#define AD7280A_CB3_TIMER_REG			0x17 /* D7 to D0, Read/write */
-#define AD7280A_CB4_TIMER_REG			0x18 /* D7 to D0, Read/write */
-#define AD7280A_CB5_TIMER_REG			0x19 /* D7 to D0, Read/write */
-#define AD7280A_CB6_TIMER_REG			0x1A /* D7 to D0, Read/write */
-#define AD7280A_PD_TIMER_REG			0x1B /* D7 to D0, Read/write */
-#define AD7280A_READ_REG			0x1C /* D7 to D0, Read/write */
-#define   AD7280A_READ_ADDR_MSK				GENMASK(7, 2)
-#define AD7280A_CNVST_CTRL_REG			0x1D /* D7 to D0, Read/write */
-
-/* Transfer fields */
-#define AD7280A_TRANS_WRITE_DEVADDR_MSK		GENMASK(31, 27)
-#define AD7280A_TRANS_WRITE_ADDR_MSK		GENMASK(26, 21)
-#define AD7280A_TRANS_WRITE_VAL_MSK		GENMASK(20, 13)
-#define AD7280A_TRANS_WRITE_ALL_MSK		BIT(12)
-#define AD7280A_TRANS_WRITE_CRC_MSK		GENMASK(10, 3)
-#define AD7280A_TRANS_WRITE_RES_PATTERN		0x2
-
-/* Layouts differ for channel vs other registers */
-#define AD7280A_TRANS_READ_DEVADDR_MSK		GENMASK(31, 27)
-#define AD7280A_TRANS_READ_CONV_CHANADDR_MSK	GENMASK(26, 23)
-#define AD7280A_TRANS_READ_CONV_DATA_MSK	GENMASK(22, 11)
-#define AD7280A_TRANS_READ_REG_REGADDR_MSK	GENMASK(26, 21)
-#define AD7280A_TRANS_READ_REG_DATA_MSK		GENMASK(20, 13)
-#define AD7280A_TRANS_READ_WRITE_ACK_MSK	BIT(10)
-#define AD7280A_TRANS_READ_CRC_MSK		GENMASK(9, 2)
-
-/* Magic value used to indicate this special case */
-#define AD7280A_ALL_CELLS				(0xAD << 16)
-
-#define AD7280A_MAX_SPI_CLK_HZ		700000 /* < 1MHz */
-#define AD7280A_MAX_CHAIN		8
-#define AD7280A_CELLS_PER_DEV		6
-#define AD7280A_BITS			12
-#define AD7280A_NUM_CH			(AD7280A_AUX_ADC_6_REG - \
-					AD7280A_CELL_VOLTAGE_1_REG + 1)
-
-#define AD7280A_CALC_VOLTAGE_CHAN_NUM(d, c) (((d) * AD7280A_CELLS_PER_DEV) + \
-					     (c))
-#define AD7280A_CALC_TEMP_CHAN_NUM(d, c)    (((d) * AD7280A_CELLS_PER_DEV) + \
-					     (c) - AD7280A_CELLS_PER_DEV)
-
-#define AD7280A_DEVADDR_MASTER		0
-#define AD7280A_DEVADDR_ALL		0x1F
-
-static const unsigned short ad7280a_n_avg[4] = {1, 2, 4, 8};
-static const unsigned short ad7280a_t_acq_ns[4] = {470, 1030, 1510, 1945};
-
-/* 5-bit device address is sent LSB first */
-static unsigned int ad7280a_devaddr(unsigned int addr)
-{
-	return ((addr & 0x1) << 4) |
-	       ((addr & 0x2) << 2) |
-	       (addr & 0x4) |
-	       ((addr & 0x8) >> 2) |
-	       ((addr & 0x10) >> 4);
-}
-
-/*
- * During a read a valid write is mandatory.
- * So writing to the highest available address (Address 0x1F) and setting the
- * address all parts bit to 0 is recommended.
- * So the TXVAL is AD7280A_DEVADDR_ALL + CRC
- */
-#define AD7280A_READ_TXVAL	0xF800030A
-
-/*
- * AD7280 CRC
- *
- * P(x) = x^8 + x^5 + x^3 + x^2 + x^1 + x^0 = 0b100101111 => 0x2F
- */
-#define POLYNOM		0x2F
-
-struct ad7280_state {
-	struct spi_device		*spi;
-	struct iio_chan_spec		*channels;
-	unsigned int			chain_last_alert_ignore;
-	bool				thermistor_term_en;
-	int				slave_num;
-	int				scan_cnt;
-	int				readback_delay_us;
-	unsigned char			crc_tab[CRC8_TABLE_SIZE];
-	u8				oversampling_ratio;
-	u8				acquisition_time;
-	unsigned char			ctrl_lb;
-	unsigned char			cell_threshhigh;
-	unsigned char			cell_threshlow;
-	unsigned char			aux_threshhigh;
-	unsigned char			aux_threshlow;
-	unsigned char			cb_mask[AD7280A_MAX_CHAIN];
-	struct mutex			lock; /* protect sensor state */
-
-	__be32				tx ____cacheline_aligned;
-	__be32				rx;
-};
-
-static unsigned char ad7280_calc_crc8(unsigned char *crc_tab, unsigned int val)
-{
-	unsigned char crc;
-
-	crc = crc_tab[val >> 16 & 0xFF];
-	crc = crc_tab[crc ^ (val >> 8 & 0xFF)];
-
-	return crc ^ (val & 0xFF);
-}
-
-static int ad7280_check_crc(struct ad7280_state *st, unsigned int val)
-{
-	unsigned char crc = ad7280_calc_crc8(st->crc_tab, val >> 10);
-
-	if (crc != ((val >> 2) & 0xFF))
-		return -EIO;
-
-	return 0;
-}
-
-/*
- * After initiating a conversion sequence we need to wait until the conversion
- * is done. The delay is typically in the range of 15..30us however depending on
- * the number of devices in the daisy chain, the number of averages taken,
- * conversion delays and acquisition time options it may take up to 250us, in
- * this case we better sleep instead of busy wait.
- */
-
-static void ad7280_delay(struct ad7280_state *st)
-{
-	if (st->readback_delay_us < 50)
-		udelay(st->readback_delay_us);
-	else
-		usleep_range(250, 500);
-}
-
-static int __ad7280_read32(struct ad7280_state *st, unsigned int *val)
-{
-	int ret;
-	struct spi_transfer t = {
-		.tx_buf	= &st->tx,
-		.rx_buf = &st->rx,
-		.len = sizeof(st->tx),
-	};
-
-	st->tx = cpu_to_be32(AD7280A_READ_TXVAL);
-
-	ret = spi_sync_transfer(st->spi, &t, 1);
-	if (ret)
-		return ret;
-
-	*val = be32_to_cpu(st->rx);
-
-	return 0;
-}
-
-static int ad7280_write(struct ad7280_state *st, unsigned int devaddr,
-			unsigned int addr, bool all, unsigned int val)
-{
-	unsigned int reg = FIELD_PREP(AD7280A_TRANS_WRITE_DEVADDR_MSK, devaddr) |
-		FIELD_PREP(AD7280A_TRANS_WRITE_ADDR_MSK, addr) |
-		FIELD_PREP(AD7280A_TRANS_WRITE_VAL_MSK, val) |
-		FIELD_PREP(AD7280A_TRANS_WRITE_ALL_MSK, all);
-
-	reg |= FIELD_PREP(AD7280A_TRANS_WRITE_CRC_MSK,
-			ad7280_calc_crc8(st->crc_tab, reg >> 11));
-	/* Reserved b010 pattern not included crc calc */
-	reg |= AD7280A_TRANS_WRITE_RES_PATTERN;
-
-	st->tx = cpu_to_be32(reg);
-
-	return spi_write(st->spi, &st->tx, sizeof(st->tx));
-}
-
-static int ad7280_read_reg(struct ad7280_state *st, unsigned int devaddr,
-			   unsigned int addr)
-{
-	int ret;
-	unsigned int tmp;
-
-	/* turns off the read operation on all parts */
-	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CTRL_HB_REG, 1,
-			   FIELD_PREP(AD7280A_CTRL_HB_CONV_INPUT_MSK,
-				      AD7280A_CTRL_HB_CONV_INPUT_ALL) |
-			   FIELD_PREP(AD7280A_CTRL_HB_CONV_RREAD_MSK,
-				      AD7280A_CTRL_HB_CONV_RREAD_NO) |
-			   FIELD_PREP(AD7280A_CTRL_HB_CONV_AVG_MSK,
-				      st->oversampling_ratio));
-	if (ret)
-		return ret;
-
-	/* turns on the read operation on the addressed part */
-	ret = ad7280_write(st, devaddr, AD7280A_CTRL_HB_REG, 0,
-			   FIELD_PREP(AD7280A_CTRL_HB_CONV_INPUT_MSK,
-				      AD7280A_CTRL_HB_CONV_INPUT_ALL) |
-			   FIELD_PREP(AD7280A_CTRL_HB_CONV_RREAD_MSK,
-				      AD7280A_CTRL_HB_CONV_RREAD_ALL) |
-			   FIELD_PREP(AD7280A_CTRL_HB_CONV_AVG_MSK,
-				      st->oversampling_ratio));
-	if (ret)
-		return ret;
-
-	/* Set register address on the part to be read from */
-	ret = ad7280_write(st, devaddr, AD7280A_READ_REG, 0,
-			   FIELD_PREP(AD7280A_READ_ADDR_MSK, addr));
-	if (ret)
-		return ret;
-
-	ret = __ad7280_read32(st, &tmp);
-	if (ret)
-		return ret;
-
-	if (ad7280_check_crc(st, tmp))
-		return -EIO;
-
-	if ((FIELD_GET(AD7280A_TRANS_READ_DEVADDR_MSK, tmp) != devaddr) ||
-	    (FIELD_GET(AD7280A_TRANS_READ_REG_REGADDR_MSK, tmp) != addr))
-		return -EFAULT;
-
-	return FIELD_GET(AD7280A_TRANS_READ_REG_DATA_MSK, tmp);
-}
-
-static int ad7280_read_channel(struct ad7280_state *st, unsigned int devaddr,
-			       unsigned int addr)
-{
-	int ret;
-	unsigned int tmp;
-
-	ret = ad7280_write(st, devaddr, AD7280A_READ_REG, 0,
-			   FIELD_PREP(AD7280A_READ_ADDR_MSK, addr));
-	if (ret)
-		return ret;
-
-	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CTRL_HB_REG, 1,
-			   FIELD_PREP(AD7280A_CTRL_HB_CONV_INPUT_MSK,
-				      AD7280A_CTRL_HB_CONV_INPUT_ALL) |
-			   FIELD_PREP(AD7280A_CTRL_HB_CONV_RREAD_MSK,
-				      AD7280A_CTRL_HB_CONV_RREAD_NO) |
-			   FIELD_PREP(AD7280A_CTRL_HB_CONV_AVG_MSK,
-				      st->oversampling_ratio));
-	if (ret)
-		return ret;
-
-	ret = ad7280_write(st, devaddr, AD7280A_CTRL_HB_REG, 0,
-			   FIELD_PREP(AD7280A_CTRL_HB_CONV_INPUT_MSK,
-				      AD7280A_CTRL_HB_CONV_INPUT_ALL) |
-			   FIELD_PREP(AD7280A_CTRL_HB_CONV_RREAD_MSK,
-				      AD7280A_CTRL_HB_CONV_RREAD_ALL) |
-			   FIELD_PREP(AD7280A_CTRL_HB_CONV_START_MSK,
-				      AD7280A_CTRL_HB_CONV_START_CS) |
-			   FIELD_PREP(AD7280A_CTRL_HB_CONV_AVG_MSK,
-				      st->oversampling_ratio));
-	if (ret)
-		return ret;
-
-	ad7280_delay(st);
-
-	ret = __ad7280_read32(st, &tmp);
-	if (ret)
-		return ret;
-
-	if (ad7280_check_crc(st, tmp))
-		return -EIO;
-
-	if ((FIELD_GET(AD7280A_TRANS_READ_DEVADDR_MSK, tmp) != devaddr) ||
-	    (FIELD_GET(AD7280A_TRANS_READ_CONV_CHANADDR_MSK, tmp) != addr))
-		return -EFAULT;
-
-	return FIELD_GET(AD7280A_TRANS_READ_CONV_DATA_MSK, tmp);
-}
-
-static int ad7280_read_all_channels(struct ad7280_state *st, unsigned int cnt,
-				    unsigned int *array)
-{
-	int i, ret;
-	unsigned int tmp, sum = 0;
-
-	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_READ_REG, 1,
-			   AD7280A_CELL_VOLTAGE_1_REG << 2);
-	if (ret)
-		return ret;
-
-	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CTRL_HB_REG, 1,
-			   FIELD_PREP(AD7280A_CTRL_HB_CONV_INPUT_MSK,
-				      AD7280A_CTRL_HB_CONV_INPUT_ALL) |
-			   FIELD_PREP(AD7280A_CTRL_HB_CONV_RREAD_MSK,
-				      AD7280A_CTRL_HB_CONV_RREAD_ALL) |
-			   FIELD_PREP(AD7280A_CTRL_HB_CONV_START_MSK,
-				      AD7280A_CTRL_HB_CONV_START_CS) |
-			   FIELD_PREP(AD7280A_CTRL_HB_CONV_AVG_MSK,
-				      st->oversampling_ratio));
-	if (ret)
-		return ret;
-
-	ad7280_delay(st);
-
-	for (i = 0; i < cnt; i++) {
-		ret = __ad7280_read32(st, &tmp);
-		if (ret)
-			return ret;
-
-		if (ad7280_check_crc(st, tmp))
-			return -EIO;
-
-		if (array)
-			array[i] = tmp;
-		/* only sum cell voltages */
-		if (FIELD_GET(AD7280A_TRANS_READ_CONV_CHANADDR_MSK, tmp) <=
-		    AD7280A_CELL_VOLTAGE_6_REG)
-			sum += FIELD_GET(AD7280A_TRANS_READ_CONV_DATA_MSK, tmp);
-	}
-
-	return sum;
-}
-
-static void ad7280_sw_power_down(void *data)
-{
-	struct ad7280_state *st = data;
-
-	ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CTRL_HB_REG, 1,
-		     AD7280A_CTRL_HB_PWRDN_SW |
-		     FIELD_PREP(AD7280A_CTRL_HB_CONV_AVG_MSK, st->oversampling_ratio));
-}
-
-static int ad7280_chain_setup(struct ad7280_state *st)
-{
-	unsigned int val, n;
-	int ret;
-
-	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CTRL_LB_REG, 1,
-			   FIELD_PREP(AD7280A_CTRL_LB_DAISY_CHAIN_RB_MSK, 1) |
-			   FIELD_PREP(AD7280A_CTRL_LB_LOCK_DEV_ADDR_MSK, 1) |
-			   AD7280A_CTRL_LB_MUST_SET |
-			   FIELD_PREP(AD7280A_CTRL_LB_SWRST_MSK, 1) |
-			   st->ctrl_lb);
-	if (ret)
-		return ret;
-
-	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CTRL_LB_REG, 1,
-			   FIELD_PREP(AD7280A_CTRL_LB_DAISY_CHAIN_RB_MSK, 1) |
-			   FIELD_PREP(AD7280A_CTRL_LB_LOCK_DEV_ADDR_MSK, 1) |
-			   AD7280A_CTRL_LB_MUST_SET |
-			   FIELD_PREP(AD7280A_CTRL_LB_SWRST_MSK, 0) |
-			   st->ctrl_lb);
-	if (ret)
-		goto error_power_down;
-
-	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_READ_REG, 1,
-			   FIELD_PREP(AD7280A_READ_ADDR_MSK, AD7280A_CTRL_LB_REG));
-	if (ret)
-		goto error_power_down;
-
-	for (n = 0; n <= AD7280A_MAX_CHAIN; n++) {
-		ret = __ad7280_read32(st, &val);
-		if (ret)
-			goto error_power_down;
-
-		if (val == 0)
-			return n - 1;
-
-		if (ad7280_check_crc(st, val)) {
-			ret = -EIO;
-			goto error_power_down;
-		}
-
-		if (n != ad7280a_devaddr(FIELD_GET(AD7280A_TRANS_READ_DEVADDR_MSK, val))) {
-			ret = -EIO;
-			goto error_power_down;
-		}
-	}
-	ret = -EFAULT;
-
-error_power_down:
-	ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CTRL_HB_REG, 1,
-		     AD7280A_CTRL_HB_PWRDN_SW |
-		     FIELD_PREP(AD7280A_CTRL_HB_CONV_AVG_MSK, st->oversampling_ratio));
-
-	return ret;
-}
-
-static ssize_t ad7280_show_balance_sw(struct iio_dev *indio_dev,
-				      uintptr_t private,
-				      const struct iio_chan_spec *chan, char *buf)
-{
-	struct ad7280_state *st = iio_priv(indio_dev);
-
-	return sysfs_emit(buf, "%d\n",
-			  !!(st->cb_mask[chan->address >> 8] &
-			     BIT(chan->address & 0xFF)));
-}
-
-static ssize_t ad7280_store_balance_sw(struct iio_dev *indio_dev,
-				       uintptr_t private,
-				       const struct iio_chan_spec *chan,
-				       const char *buf, size_t len)
-{
-	struct ad7280_state *st = iio_priv(indio_dev);
-	unsigned int devaddr, ch;
-	bool readin;
-	int ret;
-
-	ret = strtobool(buf, &readin);
-	if (ret)
-		return ret;
-
-	devaddr = chan->address >> 8;
-	ch = chan->address & 0xFF;
-
-	mutex_lock(&st->lock);
-	if (readin)
-		st->cb_mask[devaddr] |= BIT(ch);
-	else
-		st->cb_mask[devaddr] &= ~BIT(ch);
-
-	ret = ad7280_write(st, devaddr, AD7280A_CELL_BALANCE_REG, 0,
-			   FIELD_PREP(AD7280A_CELL_BALANCE_CHAN_BITMAP_MSK,
-				      st->cb_mask[devaddr]));
-	mutex_unlock(&st->lock);
-
-	return ret ? ret : len;
-}
-
-static ssize_t ad7280_show_balance_timer(struct iio_dev *indio_dev,
-					 uintptr_t private,
-					 const struct iio_chan_spec *chan,
-					 char *buf)
-{
-	struct ad7280_state *st = iio_priv(indio_dev);
-	unsigned int msecs;
-	int ret;
-
-	mutex_lock(&st->lock);
-	ret = ad7280_read_reg(st, chan->address >> 8,
-			      (chan->address & 0xFF) + AD7280A_CB1_TIMER_REG);
-	mutex_unlock(&st->lock);
-
-	if (ret < 0)
-		return ret;
-
-	msecs = FIELD_GET(AD7280A_CB_TIMER_VAL_MSK, ret) * 71500;
-
-	return sysfs_emit(buf, "%u.%u\n", msecs / 1000, msecs % 1000);
-}
-
-static ssize_t ad7280_store_balance_timer(struct iio_dev *indio_dev,
-					  uintptr_t private,
-					  const struct iio_chan_spec *chan,
-					  const char *buf, size_t len)
-{
-	struct ad7280_state *st = iio_priv(indio_dev);
-	int val, val2;
-	int ret;
-
-	ret = iio_str_to_fixpoint(buf, 1000, &val, &val2);
-	if (ret)
-		return ret;
-
-	val = val * 1000 + val2;
-	val /= 71500;
-
-	if (val > 31)
-		return -EINVAL;
-
-	mutex_lock(&st->lock);
-	ret = ad7280_write(st, chan->address >> 8,
-			   (chan->address & 0xFF) + AD7280A_CB1_TIMER_REG, 0,
-			   FIELD_PREP(AD7280A_CB_TIMER_VAL_MSK, val));
-	mutex_unlock(&st->lock);
-
-	return ret ? ret : len;
-}
-
-static const struct iio_chan_spec_ext_info ad7280_cell_ext_info[] = {
-	{
-		.name = "balance_switch_en",
-		.read = ad7280_show_balance_sw,
-		.write = ad7280_store_balance_sw,
-		.shared = IIO_SEPARATE,
-	}, {
-		.name = "balance_switch_timer",
-		.read = ad7280_show_balance_timer,
-		.write = ad7280_store_balance_timer,
-		.shared = IIO_SEPARATE,
-	},
-	{}
-};
-
-static const struct iio_event_spec ad7280_events[] = {
-	{
-		.type = IIO_EV_TYPE_THRESH,
-		.dir = IIO_EV_DIR_RISING,
-		.mask_shared_by_type = BIT(IIO_EV_INFO_VALUE),
-	}, {
-		.type = IIO_EV_TYPE_THRESH,
-		.dir = IIO_EV_DIR_FALLING,
-		.mask_shared_by_type = BIT(IIO_EV_INFO_VALUE),
-	},
-};
-
-static void ad7280_voltage_channel_init(struct iio_chan_spec *chan, int i,
-					bool irq_present)
-{
-	chan->type = IIO_VOLTAGE;
-	chan->differential = 1;
-	chan->channel = i;
-	chan->channel2 = chan->channel + 1;
-	if (irq_present) {
-		chan->event_spec = ad7280_events;
-		chan->num_event_specs = ARRAY_SIZE(ad7280_events);
-	}
-	chan->ext_info = ad7280_cell_ext_info;
-}
-
-static void ad7280_temp_channel_init(struct iio_chan_spec *chan, int i,
-				     bool irq_present)
-{
-	chan->type = IIO_TEMP;
-	chan->channel = i;
-	if (irq_present) {
-		chan->event_spec = ad7280_events;
-		chan->num_event_specs = ARRAY_SIZE(ad7280_events);
-	}
-}
-
-static void ad7280_common_fields_init(struct iio_chan_spec *chan, int addr,
-				      int cnt)
-{
-	chan->indexed = 1;
-	chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
-	chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
-	chan->info_mask_shared_by_all = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO);
-	chan->address = addr;
-	chan->scan_index = cnt;
-	chan->scan_type.sign = 'u';
-	chan->scan_type.realbits = 12;
-	chan->scan_type.storagebits = 32;
-}
-
-static void ad7280_total_voltage_channel_init(struct iio_chan_spec *chan,
-					      int cnt, int dev)
-{
-	chan->type = IIO_VOLTAGE;
-	chan->differential = 1;
-	chan->channel = 0;
-	chan->channel2 = dev * AD7280A_CELLS_PER_DEV;
-	chan->address = AD7280A_ALL_CELLS;
-	chan->indexed = 1;
-	chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
-	chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
-	chan->scan_index = cnt;
-	chan->scan_type.sign = 'u';
-	chan->scan_type.realbits = 32;
-	chan->scan_type.storagebits = 32;
-}
-
-static void ad7280_init_dev_channels(struct ad7280_state *st, int dev, int *cnt,
-				     bool irq_present)
-{
-	int addr, ch, i;
-	struct iio_chan_spec *chan;
-
-	for (ch = AD7280A_CELL_VOLTAGE_1_REG; ch <= AD7280A_AUX_ADC_6_REG; ch++) {
-		chan = &st->channels[*cnt];
-
-		if (ch < AD7280A_AUX_ADC_1_REG) {
-			i = AD7280A_CALC_VOLTAGE_CHAN_NUM(dev, ch);
-			ad7280_voltage_channel_init(chan, i, irq_present);
-		} else {
-			i = AD7280A_CALC_TEMP_CHAN_NUM(dev, ch);
-			ad7280_temp_channel_init(chan, i, irq_present);
-		}
-
-		addr = ad7280a_devaddr(dev) << 8 | ch;
-		ad7280_common_fields_init(chan, addr, *cnt);
-
-		(*cnt)++;
-	}
-}
-
-static int ad7280_channel_init(struct ad7280_state *st, bool irq_present)
-{
-	int dev, cnt = 0;
-
-	st->channels = devm_kcalloc(&st->spi->dev, (st->slave_num + 1) * 12 + 1,
-				    sizeof(*st->channels), GFP_KERNEL);
-	if (!st->channels)
-		return -ENOMEM;
-
-	for (dev = 0; dev <= st->slave_num; dev++)
-		ad7280_init_dev_channels(st, dev, &cnt, irq_present);
-
-	ad7280_total_voltage_channel_init(&st->channels[cnt], cnt, dev);
-
-	return cnt + 1;
-}
-
-static int ad7280a_read_thresh(struct iio_dev *indio_dev,
-			       const struct iio_chan_spec *chan,
-			       enum iio_event_type type,
-			       enum iio_event_direction dir,
-			       enum iio_event_info info, int *val, int *val2)
-{
-	struct ad7280_state *st = iio_priv(indio_dev);
-
-	switch (chan->type) {
-	case IIO_VOLTAGE:
-		switch (dir) {
-		case IIO_EV_DIR_RISING:
-			*val = 1000 + (st->cell_threshhigh * 1568L) / 100;
-			return IIO_VAL_INT;
-		case IIO_EV_DIR_FALLING:
-			*val = 1000 + (st->cell_threshlow * 1568L) / 100;
-			return IIO_VAL_INT;
-		default:
-			return -EINVAL;
-		}
-		break;
-	case IIO_TEMP:
-		switch (dir) {
-		case IIO_EV_DIR_RISING:
-			*val = ((st->aux_threshhigh) * 196L) / 10;
-			return IIO_VAL_INT;
-		case IIO_EV_DIR_FALLING:
-			*val = (st->aux_threshlow * 196L) / 10;
-			return IIO_VAL_INT;
-		default:
-			return -EINVAL;
-		}
-		break;
-	default:
-		return -EINVAL;
-	}
-}
-
-static int ad7280a_write_thresh(struct iio_dev *indio_dev,
-				const struct iio_chan_spec *chan,
-				enum iio_event_type type,
-				enum iio_event_direction dir,
-				enum iio_event_info info,
-				int val, int val2)
-{
-	struct ad7280_state *st = iio_priv(indio_dev);
-	unsigned int addr;
-	long value;
-	int ret;
-
-	if (val2 != 0)
-		return -EINVAL;
-
-	mutex_lock(&st->lock);
-	switch (chan->type) {
-	case IIO_VOLTAGE:
-		value = ((val - 1000) * 100) / 1568; /* LSB 15.68mV */
-		value = clamp(value, 0L, 0xFFL);
-		switch (dir) {
-		case IIO_EV_DIR_RISING:
-			addr = AD7280A_CELL_OVERVOLTAGE_REG;
-			ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, addr,
-					   1, val);
-			if (ret)
-				break;
-			st->cell_threshhigh = value;
-			break;
-		case IIO_EV_DIR_FALLING:
-			addr = AD7280A_CELL_UNDERVOLTAGE_REG;
-			ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, addr,
-					   1, val);
-			if (ret)
-				break;
-			st->cell_threshlow = value;
-			break;
-		default:
-			ret = -EINVAL;
-			goto err_unlock;
-		}
-		break;
-	case IIO_TEMP:
-		value = (val * 10) / 196; /* LSB 19.6mV */
-		value = clamp(value, 0L, 0xFFL);
-		switch (dir) {
-		case IIO_EV_DIR_RISING:
-			addr = AD7280A_AUX_ADC_OVERVOLTAGE_REG;
-			ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, addr,
-					   1, val);
-			if (ret)
-				break;
-			st->aux_threshhigh = val;
-			break;
-		case IIO_EV_DIR_FALLING:
-			addr = AD7280A_AUX_ADC_UNDERVOLTAGE_REG;
-			ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, addr,
-					   1, val);
-			if (ret)
-				break;
-			st->aux_threshlow = val;
-			break;
-		default:
-			ret = -EINVAL;
-			goto err_unlock;
-		}
-		break;
-	default:
-		ret = -EINVAL;
-		goto err_unlock;
-	}
-
-err_unlock:
-	mutex_unlock(&st->lock);
-
-	return ret;
-}
-
-static irqreturn_t ad7280_event_handler(int irq, void *private)
-{
-	struct iio_dev *indio_dev = private;
-	struct ad7280_state *st = iio_priv(indio_dev);
-	unsigned int *channels;
-	int i, ret;
-
-	channels = kcalloc(st->scan_cnt, sizeof(*channels), GFP_KERNEL);
-	if (!channels)
-		return IRQ_HANDLED;
-
-	ret = ad7280_read_all_channels(st, st->scan_cnt, channels);
-	if (ret < 0)
-		goto out;
-
-	for (i = 0; i < st->scan_cnt; i++) {
-		unsigned int val;
-
-		val = FIELD_GET(AD7280A_TRANS_READ_CONV_DATA_MSK, channels[i]);
-		if (FIELD_GET(AD7280A_TRANS_READ_CONV_CHANADDR_MSK, channels[i]) <=
-		    AD7280A_CELL_VOLTAGE_6_REG) {
-			if (val >= st->cell_threshhigh) {
-				u64 tmp = IIO_EVENT_CODE(IIO_VOLTAGE, 1, 0,
-							 IIO_EV_DIR_RISING,
-							 IIO_EV_TYPE_THRESH,
-							 0, 0, 0);
-				iio_push_event(indio_dev, tmp,
-					       iio_get_time_ns(indio_dev));
-			} else if (val <= st->cell_threshlow) {
-				u64 tmp = IIO_EVENT_CODE(IIO_VOLTAGE, 1, 0,
-							 IIO_EV_DIR_FALLING,
-							 IIO_EV_TYPE_THRESH,
-							 0, 0, 0);
-				iio_push_event(indio_dev, tmp,
-					       iio_get_time_ns(indio_dev));
-			}
-		} else {
-			if (val >= st->aux_threshhigh) {
-				u64 tmp = IIO_UNMOD_EVENT_CODE(IIO_TEMP, 0,
-							IIO_EV_TYPE_THRESH,
-							IIO_EV_DIR_RISING);
-				iio_push_event(indio_dev, tmp,
-					       iio_get_time_ns(indio_dev));
-			} else if (val <= st->aux_threshlow) {
-				u64 tmp = IIO_UNMOD_EVENT_CODE(IIO_TEMP, 0,
-							IIO_EV_TYPE_THRESH,
-							IIO_EV_DIR_FALLING);
-				iio_push_event(indio_dev, tmp,
-					       iio_get_time_ns(indio_dev));
-			}
-		}
-	}
-
-out:
-	kfree(channels);
-
-	return IRQ_HANDLED;
-}
-
-static void ad7280_update_delay(struct ad7280_state *st)
-{
-	/*
-	 * Total Conversion Time = ((tACQ + tCONV) *
-	 *			   (Number of Conversions per Part)) −
-	 *			   tACQ + ((N - 1) * tDELAY)
-	 *
-	 * Readback Delay = Total Conversion Time + tWAIT
-	 */
-
-	st->readback_delay_us =
-		((ad7280a_t_acq_ns[st->acquisition_time & 0x3] + 720) *
-			(AD7280A_NUM_CH * ad7280a_n_avg[st->oversampling_ratio & 0x3])) -
-		ad7280a_t_acq_ns[st->acquisition_time & 0x3] + st->slave_num * 250;
-
-	/* Convert to usecs */
-	st->readback_delay_us = DIV_ROUND_UP(st->readback_delay_us, 1000);
-	st->readback_delay_us += 5; /* Add tWAIT */
-}
-
-static int ad7280_read_raw(struct iio_dev *indio_dev,
-			   struct iio_chan_spec const *chan,
-			   int *val,
-			   int *val2,
-			   long m)
-{
-	struct ad7280_state *st = iio_priv(indio_dev);
-	int ret;
-
-	switch (m) {
-	case IIO_CHAN_INFO_RAW:
-		mutex_lock(&st->lock);
-		if (chan->address == AD7280A_ALL_CELLS)
-			ret = ad7280_read_all_channels(st, st->scan_cnt, NULL);
-		else
-			ret = ad7280_read_channel(st, chan->address >> 8,
-						  chan->address & 0xFF);
-		mutex_unlock(&st->lock);
-
-		if (ret < 0)
-			return ret;
-
-		*val = ret;
-
-		return IIO_VAL_INT;
-	case IIO_CHAN_INFO_SCALE:
-		if ((chan->address & 0xFF) <= AD7280A_CELL_VOLTAGE_6_REG)
-			*val = 4000;
-		else
-			*val = 5000;
-
-		*val2 = AD7280A_BITS;
-		return IIO_VAL_FRACTIONAL_LOG2;
-	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
-		*val = ad7280a_n_avg[st->oversampling_ratio];
-		return IIO_VAL_INT;
-	}
-	return -EINVAL;
-}
-
-static int ad7280_write_raw(struct iio_dev *indio_dev,
-			    struct iio_chan_spec const *chan,
-			    int val, int val2, long mask)
-{
-	struct ad7280_state *st = iio_priv(indio_dev);
-	int i;
-
-	switch (mask) {
-	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
-		if (val2 != 0)
-			return -EINVAL;
-		for (i = 0; i < ARRAY_SIZE(ad7280a_n_avg); i++) {
-			if (val == ad7280a_n_avg[i]) {
-				st->oversampling_ratio = i;
-				ad7280_update_delay(st);
-				return 0;
-			}
-		}
-		return -EINVAL;
-	default:
-		return -EINVAL;
-	}
-}
-
-static const struct iio_info ad7280_info = {
-	.read_raw = ad7280_read_raw,
-	.write_raw = ad7280_write_raw,
-	.read_event_value = &ad7280a_read_thresh,
-	.write_event_value = &ad7280a_write_thresh,
-};
-
-static const struct iio_info ad7280_info_no_irq = {
-	.read_raw = ad7280_read_raw,
-	.write_raw = ad7280_write_raw,
-};
-
-static int ad7280_probe(struct spi_device *spi)
-{
-	struct device *dev = &spi->dev;
-	struct ad7280_state *st;
-	int ret;
-	struct iio_dev *indio_dev;
-
-	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
-	if (!indio_dev)
-		return -ENOMEM;
-
-	st = iio_priv(indio_dev);
-	spi_set_drvdata(spi, indio_dev);
-	st->spi = spi;
-	mutex_init(&st->lock);
-
-	st->thermistor_term_en =
-		device_property_read_bool(dev, "adi,thermistor-termination");
-
-	if (device_property_present(dev, "adi,acquisition-time-ns")) {
-		u32 val;
-
-		ret = device_property_read_u32(dev, "adi,acquisition-time-ns", &val);
-		if (ret)
-			return ret;
-
-		switch (val) {
-		case 400:
-			st->acquisition_time = AD7280A_CTRL_LB_ACQ_TIME_400ns;
-			break;
-		case 800:
-			st->acquisition_time = AD7280A_CTRL_LB_ACQ_TIME_800ns;
-			break;
-		case 1200:
-			st->acquisition_time = AD7280A_CTRL_LB_ACQ_TIME_1200ns;
-			break;
-		case 1600:
-			st->acquisition_time = AD7280A_CTRL_LB_ACQ_TIME_1600ns;
-			break;
-		default:
-			dev_err(dev, "Firmware provided acquisition time is invalid\n");
-			return -EINVAL;
-		}
-	} else {
-		st->acquisition_time = AD7280A_CTRL_LB_ACQ_TIME_400ns;
-	}
-
-	/* Alert masks are intended for when particular inputs are not wired up */
-	if (device_property_present(dev, "adi,voltage-alert-last-chan")) {
-		u32 val;
-
-		ret = device_property_read_u32(dev, "adi,voltage-alert-last-chan", &val);
-		if (ret)
-			return ret;
-
-		switch (val) {
-		case 3:
-			st->chain_last_alert_ignore |= AD7280A_ALERT_REMOVE_VIN4_VIN5;
-			break;
-		case 4:
-			st->chain_last_alert_ignore |= AD7280A_ALERT_REMOVE_VIN5;
-			break;
-		case 5:
-			break;
-		default:
-			dev_err(dev,
-				"Firmware provided last voltage alert channel invalid\n");
-			break;
-		}
-	}
-	crc8_populate_msb(st->crc_tab, POLYNOM);
-
-	st->spi->max_speed_hz = AD7280A_MAX_SPI_CLK_HZ;
-	st->spi->mode = SPI_MODE_1;
-	spi_setup(st->spi);
-
-	st->ctrl_lb = FIELD_PREP(AD7280A_CTRL_LB_ACQ_TIME_MSK, st->acquisition_time) |
-		FIELD_PREP(AD7280A_CTRL_LB_THERMISTOR_MSK, st->thermistor_term_en);
-	st->oversampling_ratio = 0; /* No oversampling */
-
-	ret = ad7280_chain_setup(st);
-	if (ret < 0)
-		return ret;
-
-	st->slave_num = ret;
-	st->scan_cnt = (st->slave_num + 1) * AD7280A_NUM_CH;
-	st->cell_threshhigh = 0xFF;
-	st->aux_threshhigh = 0xFF;
-
-	ret = devm_add_action_or_reset(dev, ad7280_sw_power_down, st);
-	if (ret)
-		return ret;
-
-	ad7280_update_delay(st);
-
-	indio_dev->name = spi_get_device_id(spi)->name;
-	indio_dev->modes = INDIO_DIRECT_MODE;
-
-	ret = ad7280_channel_init(st, spi->irq > 0);
-	if (ret < 0)
-		return ret;
-
-	indio_dev->num_channels = ret;
-	indio_dev->channels = st->channels;
-	if (spi->irq > 0) {
-		ret = ad7280_write(st, AD7280A_DEVADDR_MASTER,
-				   AD7280A_ALERT_REG, 1,
-				   AD7280A_ALERT_RELAY_SIG_CHAIN_DOWN);
-		if (ret)
-			return ret;
-
-		ret = ad7280_write(st, ad7280a_devaddr(st->slave_num),
-				   AD7280A_ALERT_REG, 0,
-				   AD7280A_ALERT_GEN_STATIC_HIGH |
-				   FIELD_PREP(AD7280A_ALERT_REMOVE_MSK,
-					      st->chain_last_alert_ignore));
-		if (ret)
-			return ret;
-
-		ret = devm_request_threaded_irq(dev, spi->irq,
-						NULL,
-						ad7280_event_handler,
-						IRQF_TRIGGER_FALLING |
-						IRQF_ONESHOT,
-						indio_dev->name,
-						indio_dev);
-		if (ret)
-			return ret;
-
-		indio_dev->info = &ad7280_info;
-	} else {
-		indio_dev->info = &ad7280_info_no_irq;
-	}
-
-	return devm_iio_device_register(dev, indio_dev);
-}
-
-static const struct spi_device_id ad7280_id[] = {
-	{"ad7280a", 0},
-	{}
-};
-MODULE_DEVICE_TABLE(spi, ad7280_id);
-
-static struct spi_driver ad7280_driver = {
-	.driver = {
-		.name	= "ad7280",
-	},
-	.probe		= ad7280_probe,
-	.id_table	= ad7280_id,
-};
-module_spi_driver(ad7280_driver);
-
-MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
-MODULE_DESCRIPTION("Analog Devices AD7280A");
-MODULE_LICENSE("GPL v2");