Move ad5933 impedance-analyzer driver from staging to mainline.

The ad5933 is a high precision impedance converter system solution that
combines an on-board frequency generator with an analog-to-digital
converter (ADC). This driver was designed to be compatible with both
ad5933 and ad5934 chips.

Signed-off-by: Marcelo Schmitt <marcelo.schmi...@gmail.com>
---
 drivers/iio/impedance-analyzer/Kconfig        |  18 +
 drivers/iio/impedance-analyzer/Makefile       |   5 +
 drivers/iio/impedance-analyzer/ad5933.c       | 811 ++++++++++++++++++
 .../staging/iio/impedance-analyzer/Kconfig    |  18 -
 .../staging/iio/impedance-analyzer/Makefile   |   5 -
 .../staging/iio/impedance-analyzer/ad5933.c   | 811 ------------------
 6 files changed, 834 insertions(+), 834 deletions(-)
 create mode 100644 drivers/iio/impedance-analyzer/Kconfig
 create mode 100644 drivers/iio/impedance-analyzer/Makefile
 create mode 100644 drivers/iio/impedance-analyzer/ad5933.c
 delete mode 100644 drivers/staging/iio/impedance-analyzer/Kconfig
 delete mode 100644 drivers/staging/iio/impedance-analyzer/Makefile
 delete mode 100644 drivers/staging/iio/impedance-analyzer/ad5933.c

diff --git a/drivers/iio/impedance-analyzer/Kconfig 
b/drivers/iio/impedance-analyzer/Kconfig
new file mode 100644
index 000000000000..b9a679cdd146
--- /dev/null
+++ b/drivers/iio/impedance-analyzer/Kconfig
@@ -0,0 +1,18 @@
+#
+# Impedance Converter, Network Analyzer drivers
+#
+menu "Network Analyzer, Impedance Converters"
+
+config AD5933
+       tristate "Analog Devices AD5933, AD5934 driver"
+       depends on I2C
+       select IIO_BUFFER
+       select IIO_KFIFO_BUF
+       help
+         Say yes here to build support for Analog Devices Impedance Converter,
+         Network Analyzer, AD5933/4.
+
+         To compile this driver as a module, choose M here: the
+         module will be called ad5933.
+
+endmenu
diff --git a/drivers/iio/impedance-analyzer/Makefile 
b/drivers/iio/impedance-analyzer/Makefile
new file mode 100644
index 000000000000..7604d786583e
--- /dev/null
+++ b/drivers/iio/impedance-analyzer/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile for Impedance Converter, Network Analyzer drivers
+#
+
+obj-$(CONFIG_AD5933) += ad5933.o
diff --git a/drivers/iio/impedance-analyzer/ad5933.c 
b/drivers/iio/impedance-analyzer/ad5933.c
new file mode 100644
index 000000000000..d75bdfbf93de
--- /dev/null
+++ b/drivers/iio/impedance-analyzer/ad5933.c
@@ -0,0 +1,811 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AD5933 AD5934 Impedance Converter, Network Analyzer
+ *
+ * Copyright 2011 Analog Devices Inc.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/kfifo_buf.h>
+#include <linux/iio/sysfs.h>
+
+/* AD5933/AD5934 Registers */
+#define AD5933_REG_CONTROL_HB          0x80    /* R/W, 1 byte */
+#define AD5933_REG_CONTROL_LB          0x81    /* R/W, 1 byte */
+#define AD5933_REG_FREQ_START          0x82    /* R/W, 3 bytes */
+#define AD5933_REG_FREQ_INC            0x85    /* R/W, 3 bytes */
+#define AD5933_REG_INC_NUM             0x88    /* R/W, 2 bytes, 9 bit */
+#define AD5933_REG_SETTLING_CYCLES     0x8A    /* R/W, 2 bytes */
+#define AD5933_REG_STATUS              0x8F    /* R, 1 byte */
+#define AD5933_REG_TEMP_DATA           0x92    /* R, 2 bytes*/
+#define AD5933_REG_REAL_DATA           0x94    /* R, 2 bytes*/
+#define AD5933_REG_IMAG_DATA           0x96    /* R, 2 bytes*/
+
+/* AD5933_REG_CONTROL_HB Bits */
+#define AD5933_CTRL_INIT_START_FREQ    (0x1 << 4)
+#define AD5933_CTRL_START_SWEEP                (0x2 << 4)
+#define AD5933_CTRL_INC_FREQ           (0x3 << 4)
+#define AD5933_CTRL_REPEAT_FREQ                (0x4 << 4)
+#define AD5933_CTRL_MEASURE_TEMP       (0x9 << 4)
+#define AD5933_CTRL_POWER_DOWN         (0xA << 4)
+#define AD5933_CTRL_STANDBY            (0xB << 4)
+
+#define AD5933_CTRL_RANGE_2000mVpp     (0x0 << 1)
+#define AD5933_CTRL_RANGE_200mVpp      (0x1 << 1)
+#define AD5933_CTRL_RANGE_400mVpp      (0x2 << 1)
+#define AD5933_CTRL_RANGE_1000mVpp     (0x3 << 1)
+#define AD5933_CTRL_RANGE(x)           ((x) << 1)
+
+#define AD5933_CTRL_PGA_GAIN_1         (0x1 << 0)
+#define AD5933_CTRL_PGA_GAIN_5         (0x0 << 0)
+
+/* AD5933_REG_CONTROL_LB Bits */
+#define AD5933_CTRL_RESET              (0x1 << 4)
+#define AD5933_CTRL_INT_SYSCLK         (0x0 << 3)
+#define AD5933_CTRL_EXT_SYSCLK         (0x1 << 3)
+
+/* AD5933_REG_STATUS Bits */
+#define AD5933_STAT_TEMP_VALID         (0x1 << 0)
+#define AD5933_STAT_DATA_VALID         (0x1 << 1)
+#define AD5933_STAT_SWEEP_DONE         (0x1 << 2)
+
+/* I2C Block Commands */
+#define AD5933_I2C_BLOCK_WRITE         0xA0
+#define AD5933_I2C_BLOCK_READ          0xA1
+#define AD5933_I2C_ADDR_POINTER                0xB0
+
+/* Device Specs */
+#define AD5933_INT_OSC_FREQ_Hz         16776000
+#define AD5933_MAX_OUTPUT_FREQ_Hz      100000
+#define AD5933_MAX_RETRIES             100
+
+#define AD5933_OUT_RANGE               1
+#define AD5933_OUT_RANGE_AVAIL         2
+#define AD5933_OUT_SETTLING_CYCLES     3
+#define AD5933_IN_PGA_GAIN             4
+#define AD5933_IN_PGA_GAIN_AVAIL       5
+#define AD5933_FREQ_POINTS             6
+
+#define AD5933_POLL_TIME_ms            10
+#define AD5933_INIT_EXCITATION_TIME_ms 100
+
+struct ad5933_state {
+       struct i2c_client               *client;
+       struct regulator                *reg;
+       struct clk                      *mclk;
+       struct delayed_work             work;
+       struct mutex                    lock; /* Protect sensor state */
+       unsigned long                   mclk_hz;
+       unsigned char                   ctrl_hb;
+       unsigned char                   ctrl_lb;
+       unsigned int                    range_avail[4];
+       unsigned short                  vref_mv;
+       unsigned short                  settling_cycles;
+       unsigned short                  freq_points;
+       unsigned int                    freq_start;
+       unsigned int                    freq_inc;
+       unsigned int                    state;
+       unsigned int                    poll_time_jiffies;
+};
+
+#define AD5933_CHANNEL(_type, _extend_name, _info_mask_separate, _address, \
+               _scan_index, _realbits) { \
+       .type = (_type), \
+       .extend_name = (_extend_name), \
+       .info_mask_separate = (_info_mask_separate), \
+       .address = (_address), \
+       .scan_index = (_scan_index), \
+       .scan_type = { \
+               .sign = 's', \
+               .realbits = (_realbits), \
+               .storagebits = 16, \
+       }, \
+}
+
+static const struct iio_chan_spec ad5933_channels[] = {
+       AD5933_CHANNEL(IIO_TEMP, NULL, BIT(IIO_CHAN_INFO_RAW) |
+               BIT(IIO_CHAN_INFO_SCALE), AD5933_REG_TEMP_DATA, -1, 14),
+       /* Ring Channels */
+       AD5933_CHANNEL(IIO_VOLTAGE, "real", 0, AD5933_REG_REAL_DATA, 0, 16),
+       AD5933_CHANNEL(IIO_VOLTAGE, "imag", 0, AD5933_REG_IMAG_DATA, 1, 16),
+};
+
+static int ad5933_i2c_write(struct i2c_client *client, u8 reg, u8 len, u8 
*data)
+{
+       int ret;
+
+       while (len--) {
+               ret = i2c_smbus_write_byte_data(client, reg++, *data++);
+               if (ret < 0) {
+                       dev_err(&client->dev, "I2C write error\n");
+                       return ret;
+               }
+       }
+       return 0;
+}
+
+static int ad5933_i2c_read(struct i2c_client *client, u8 reg, u8 len, u8 *data)
+{
+       int ret;
+
+       while (len--) {
+               ret = i2c_smbus_read_byte_data(client, reg++);
+               if (ret < 0) {
+                       dev_err(&client->dev, "I2C read error\n");
+                       return ret;
+               }
+               *data++ = ret;
+       }
+       return 0;
+}
+
+static int ad5933_cmd(struct ad5933_state *st, unsigned char cmd)
+{
+       unsigned char dat = st->ctrl_hb | cmd;
+
+       return ad5933_i2c_write(st->client,
+                       AD5933_REG_CONTROL_HB, 1, &dat);
+}
+
+static int ad5933_reset(struct ad5933_state *st)
+{
+       unsigned char dat = st->ctrl_lb | AD5933_CTRL_RESET;
+
+       return ad5933_i2c_write(st->client,
+                       AD5933_REG_CONTROL_LB, 1, &dat);
+}
+
+static int ad5933_wait_busy(struct ad5933_state *st, unsigned char event)
+{
+       unsigned char val, timeout = AD5933_MAX_RETRIES;
+       int ret;
+
+       while (timeout--) {
+               ret =  ad5933_i2c_read(st->client, AD5933_REG_STATUS, 1, &val);
+               if (ret < 0)
+                       return ret;
+               if (val & event)
+                       return val;
+               cpu_relax();
+               mdelay(1);
+       }
+
+       return -EAGAIN;
+}
+
+static int ad5933_set_freq(struct ad5933_state *st,
+                          unsigned int reg, unsigned long freq)
+{
+       unsigned long long freqreg;
+       union {
+               __be32 d32;
+               u8 d8[4];
+       } dat;
+
+       freqreg = (u64)freq * (u64)(1 << 27);
+       do_div(freqreg, st->mclk_hz / 4);
+
+       switch (reg) {
+       case AD5933_REG_FREQ_START:
+               st->freq_start = freq;
+               break;
+       case AD5933_REG_FREQ_INC:
+               st->freq_inc = freq;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       dat.d32 = cpu_to_be32(freqreg);
+       return ad5933_i2c_write(st->client, reg, 3, &dat.d8[1]);
+}
+
+static int ad5933_setup(struct ad5933_state *st)
+{
+       __be16 dat;
+       int ret;
+
+       ret = ad5933_reset(st);
+       if (ret < 0)
+               return ret;
+
+       ret = ad5933_set_freq(st, AD5933_REG_FREQ_START, 10000);
+       if (ret < 0)
+               return ret;
+
+       ret = ad5933_set_freq(st, AD5933_REG_FREQ_INC, 200);
+       if (ret < 0)
+               return ret;
+
+       st->settling_cycles = 10;
+       dat = cpu_to_be16(st->settling_cycles);
+
+       ret = ad5933_i2c_write(st->client,
+                              AD5933_REG_SETTLING_CYCLES,
+                              2, (u8 *)&dat);
+       if (ret < 0)
+               return ret;
+
+       st->freq_points = 100;
+       dat = cpu_to_be16(st->freq_points);
+
+       return ad5933_i2c_write(st->client, AD5933_REG_INC_NUM, 2, (u8 *)&dat);
+}
+
+static void ad5933_calc_out_ranges(struct ad5933_state *st)
+{
+       int i;
+       unsigned int normalized_3v3[4] = {1980, 198, 383, 970};
+
+       for (i = 0; i < 4; i++)
+               st->range_avail[i] = normalized_3v3[i] * st->vref_mv / 3300;
+}
+
+/*
+ * handles: AD5933_REG_FREQ_START and AD5933_REG_FREQ_INC
+ */
+
+static ssize_t ad5933_show_frequency(struct device *dev,
+                                    struct device_attribute *attr,
+                                    char *buf)
+{
+       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+       struct ad5933_state *st = iio_priv(indio_dev);
+       struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+       int ret;
+       unsigned long long freqreg;
+       union {
+               __be32 d32;
+               u8 d8[4];
+       } dat;
+
+       ret = iio_device_claim_direct_mode(indio_dev);
+       if (ret)
+               return ret;
+       ret = ad5933_i2c_read(st->client, this_attr->address, 3, &dat.d8[1]);
+       iio_device_release_direct_mode(indio_dev);
+       if (ret < 0)
+               return ret;
+
+       freqreg = be32_to_cpu(dat.d32) & 0xFFFFFF;
+
+       freqreg = (u64)freqreg * (u64)(st->mclk_hz / 4);
+       do_div(freqreg, 1 << 27);
+
+       return sprintf(buf, "%d\n", (int)freqreg);
+}
+
+static ssize_t ad5933_store_frequency(struct device *dev,
+                                     struct device_attribute *attr,
+                                     const char *buf,
+                                     size_t len)
+{
+       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+       struct ad5933_state *st = iio_priv(indio_dev);
+       struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+       unsigned long val;
+       int ret;
+
+       ret = kstrtoul(buf, 10, &val);
+       if (ret)
+               return ret;
+
+       if (val > AD5933_MAX_OUTPUT_FREQ_Hz)
+               return -EINVAL;
+
+       ret = iio_device_claim_direct_mode(indio_dev);
+       if (ret)
+               return ret;
+       ret = ad5933_set_freq(st, this_attr->address, val);
+       iio_device_release_direct_mode(indio_dev);
+
+       return ret ? ret : len;
+}
+
+static IIO_DEVICE_ATTR(out_voltage0_freq_start, 0644,
+                       ad5933_show_frequency,
+                       ad5933_store_frequency,
+                       AD5933_REG_FREQ_START);
+
+static IIO_DEVICE_ATTR(out_voltage0_freq_increment, 0644,
+                       ad5933_show_frequency,
+                       ad5933_store_frequency,
+                       AD5933_REG_FREQ_INC);
+
+static ssize_t ad5933_show(struct device *dev,
+                          struct device_attribute *attr,
+                          char *buf)
+{
+       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+       struct ad5933_state *st = iio_priv(indio_dev);
+       struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+       int ret = 0, len = 0;
+
+       mutex_lock(&st->lock);
+       switch ((u32)this_attr->address) {
+       case AD5933_OUT_RANGE:
+               len = sprintf(buf, "%u\n",
+                             st->range_avail[(st->ctrl_hb >> 1) & 0x3]);
+               break;
+       case AD5933_OUT_RANGE_AVAIL:
+               len = sprintf(buf, "%u %u %u %u\n", st->range_avail[0],
+                             st->range_avail[3], st->range_avail[2],
+                             st->range_avail[1]);
+               break;
+       case AD5933_OUT_SETTLING_CYCLES:
+               len = sprintf(buf, "%d\n", st->settling_cycles);
+               break;
+       case AD5933_IN_PGA_GAIN:
+               len = sprintf(buf, "%s\n",
+                             (st->ctrl_hb & AD5933_CTRL_PGA_GAIN_1) ?
+                             "1" : "0.2");
+               break;
+       case AD5933_IN_PGA_GAIN_AVAIL:
+               len = sprintf(buf, "1 0.2\n");
+               break;
+       case AD5933_FREQ_POINTS:
+               len = sprintf(buf, "%d\n", st->freq_points);
+               break;
+       default:
+               ret = -EINVAL;
+       }
+
+       mutex_unlock(&st->lock);
+       return ret ? ret : len;
+}
+
+static ssize_t ad5933_store(struct device *dev,
+                           struct device_attribute *attr,
+                           const char *buf,
+                           size_t len)
+{
+       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+       struct ad5933_state *st = iio_priv(indio_dev);
+       struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+       u16 val;
+       int i, ret = 0;
+       __be16 dat;
+
+       if (this_attr->address != AD5933_IN_PGA_GAIN) {
+               ret = kstrtou16(buf, 10, &val);
+               if (ret)
+                       return ret;
+       }
+
+       ret = iio_device_claim_direct_mode(indio_dev);
+       if (ret)
+               return ret;
+       mutex_lock(&st->lock);
+       switch ((u32)this_attr->address) {
+       case AD5933_OUT_RANGE:
+               ret = -EINVAL;
+               for (i = 0; i < 4; i++)
+                       if (val == st->range_avail[i]) {
+                               st->ctrl_hb &= ~AD5933_CTRL_RANGE(0x3);
+                               st->ctrl_hb |= AD5933_CTRL_RANGE(i);
+                               ret = ad5933_cmd(st, 0);
+                               break;
+                       }
+               break;
+       case AD5933_IN_PGA_GAIN:
+               if (sysfs_streq(buf, "1")) {
+                       st->ctrl_hb |= AD5933_CTRL_PGA_GAIN_1;
+               } else if (sysfs_streq(buf, "0.2")) {
+                       st->ctrl_hb &= ~AD5933_CTRL_PGA_GAIN_1;
+               } else {
+                       ret = -EINVAL;
+                       break;
+               }
+               ret = ad5933_cmd(st, 0);
+               break;
+       case AD5933_OUT_SETTLING_CYCLES:
+               val = clamp(val, (u16)0, (u16)0x7FF);
+               st->settling_cycles = val;
+
+               /* 2x, 4x handling, see datasheet */
+               if (val > 1022)
+                       val = (val >> 2) | (3 << 9);
+               else if (val > 511)
+                       val = (val >> 1) | (1 << 9);
+
+               dat = cpu_to_be16(val);
+               ret = ad5933_i2c_write(st->client,
+                                      AD5933_REG_SETTLING_CYCLES,
+                                      2, (u8 *)&dat);
+               break;
+       case AD5933_FREQ_POINTS:
+               val = clamp(val, (u16)0, (u16)511);
+               st->freq_points = val;
+
+               dat = cpu_to_be16(val);
+               ret = ad5933_i2c_write(st->client, AD5933_REG_INC_NUM, 2,
+                                      (u8 *)&dat);
+               break;
+       default:
+               ret = -EINVAL;
+       }
+
+       mutex_unlock(&st->lock);
+       iio_device_release_direct_mode(indio_dev);
+       return ret ? ret : len;
+}
+
+static IIO_DEVICE_ATTR(out_voltage0_scale, 0644,
+                       ad5933_show,
+                       ad5933_store,
+                       AD5933_OUT_RANGE);
+
+static IIO_DEVICE_ATTR(out_voltage0_scale_available, 0444,
+                       ad5933_show,
+                       NULL,
+                       AD5933_OUT_RANGE_AVAIL);
+
+static IIO_DEVICE_ATTR(in_voltage0_scale, 0644,
+                       ad5933_show,
+                       ad5933_store,
+                       AD5933_IN_PGA_GAIN);
+
+static IIO_DEVICE_ATTR(in_voltage0_scale_available, 0444,
+                       ad5933_show,
+                       NULL,
+                       AD5933_IN_PGA_GAIN_AVAIL);
+
+static IIO_DEVICE_ATTR(out_voltage0_freq_points, 0644,
+                       ad5933_show,
+                       ad5933_store,
+                       AD5933_FREQ_POINTS);
+
+static IIO_DEVICE_ATTR(out_voltage0_settling_cycles, 0644,
+                       ad5933_show,
+                       ad5933_store,
+                       AD5933_OUT_SETTLING_CYCLES);
+
+/*
+ * note:
+ * ideally we would handle the scale attributes via the iio_info
+ * (read|write)_raw methods, however this part is a untypical since we
+ * don't create dedicated sysfs channel attributes for out0 and in0.
+ */
+static struct attribute *ad5933_attributes[] = {
+       &iio_dev_attr_out_voltage0_scale.dev_attr.attr,
+       &iio_dev_attr_out_voltage0_scale_available.dev_attr.attr,
+       &iio_dev_attr_out_voltage0_freq_start.dev_attr.attr,
+       &iio_dev_attr_out_voltage0_freq_increment.dev_attr.attr,
+       &iio_dev_attr_out_voltage0_freq_points.dev_attr.attr,
+       &iio_dev_attr_out_voltage0_settling_cycles.dev_attr.attr,
+       &iio_dev_attr_in_voltage0_scale.dev_attr.attr,
+       &iio_dev_attr_in_voltage0_scale_available.dev_attr.attr,
+       NULL
+};
+
+static const struct attribute_group ad5933_attribute_group = {
+       .attrs = ad5933_attributes,
+};
+
+static int ad5933_read_raw(struct iio_dev *indio_dev,
+                          struct iio_chan_spec const *chan,
+                          int *val,
+                          int *val2,
+                          long m)
+{
+       struct ad5933_state *st = iio_priv(indio_dev);
+       __be16 dat;
+       int ret;
+
+       switch (m) {
+       case IIO_CHAN_INFO_RAW:
+               ret = iio_device_claim_direct_mode(indio_dev);
+               if (ret)
+                       return ret;
+               ret = ad5933_cmd(st, AD5933_CTRL_MEASURE_TEMP);
+               if (ret < 0)
+                       goto out;
+               ret = ad5933_wait_busy(st, AD5933_STAT_TEMP_VALID);
+               if (ret < 0)
+                       goto out;
+
+               ret = ad5933_i2c_read(st->client,
+                                     AD5933_REG_TEMP_DATA,
+                                     2, (u8 *)&dat);
+               if (ret < 0)
+                       goto out;
+               iio_device_release_direct_mode(indio_dev);
+               *val = sign_extend32(be16_to_cpu(dat), 13);
+
+               return IIO_VAL_INT;
+       case IIO_CHAN_INFO_SCALE:
+               *val = 1000;
+               *val2 = 5;
+               return IIO_VAL_FRACTIONAL_LOG2;
+       }
+
+       return -EINVAL;
+out:
+       iio_device_release_direct_mode(indio_dev);
+       return ret;
+}
+
+static const struct iio_info ad5933_info = {
+       .read_raw = ad5933_read_raw,
+       .attrs = &ad5933_attribute_group,
+};
+
+static int ad5933_ring_preenable(struct iio_dev *indio_dev)
+{
+       struct ad5933_state *st = iio_priv(indio_dev);
+       int ret;
+
+       if (bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength))
+               return -EINVAL;
+
+       ret = ad5933_reset(st);
+       if (ret < 0)
+               return ret;
+
+       ret = ad5933_cmd(st, AD5933_CTRL_STANDBY);
+       if (ret < 0)
+               return ret;
+
+       ret = ad5933_cmd(st, AD5933_CTRL_INIT_START_FREQ);
+       if (ret < 0)
+               return ret;
+
+       st->state = AD5933_CTRL_INIT_START_FREQ;
+
+       return 0;
+}
+
+static int ad5933_ring_postenable(struct iio_dev *indio_dev)
+{
+       struct ad5933_state *st = iio_priv(indio_dev);
+
+       /*
+        * AD5933_CTRL_INIT_START_FREQ:
+        * High Q complex circuits require a long time to reach steady state.
+        * To facilitate the measurement of such impedances, this mode allows
+        * the user full control of the settling time requirement before
+        * entering start frequency sweep mode where the impedance measurement
+        * takes place. In this mode the impedance is excited with the
+        * programmed start frequency (ad5933_ring_preenable),
+        * but no measurement takes place.
+        */
+
+       schedule_delayed_work(&st->work,
+                             msecs_to_jiffies(AD5933_INIT_EXCITATION_TIME_ms));
+       return 0;
+}
+
+static int ad5933_ring_postdisable(struct iio_dev *indio_dev)
+{
+       struct ad5933_state *st = iio_priv(indio_dev);
+
+       cancel_delayed_work_sync(&st->work);
+       return ad5933_cmd(st, AD5933_CTRL_POWER_DOWN);
+}
+
+static const struct iio_buffer_setup_ops ad5933_ring_setup_ops = {
+       .preenable = ad5933_ring_preenable,
+       .postenable = ad5933_ring_postenable,
+       .postdisable = ad5933_ring_postdisable,
+};
+
+static int ad5933_register_ring_funcs_and_init(struct iio_dev *indio_dev)
+{
+       struct iio_buffer *buffer;
+
+       buffer = iio_kfifo_allocate();
+       if (!buffer)
+               return -ENOMEM;
+
+       iio_device_attach_buffer(indio_dev, buffer);
+
+       /* Ring buffer functions - here trigger setup related */
+       indio_dev->setup_ops = &ad5933_ring_setup_ops;
+
+       return 0;
+}
+
+static void ad5933_work(struct work_struct *work)
+{
+       struct ad5933_state *st = container_of(work,
+               struct ad5933_state, work.work);
+       struct iio_dev *indio_dev = i2c_get_clientdata(st->client);
+       __be16 buf[2];
+       int val[2];
+       unsigned char status;
+       int ret;
+
+       if (st->state == AD5933_CTRL_INIT_START_FREQ) {
+               /* start sweep */
+               ad5933_cmd(st, AD5933_CTRL_START_SWEEP);
+               st->state = AD5933_CTRL_START_SWEEP;
+               schedule_delayed_work(&st->work, st->poll_time_jiffies);
+               return;
+       }
+
+       ret = ad5933_i2c_read(st->client, AD5933_REG_STATUS, 1, &status);
+       if (ret)
+               return;
+
+       if (status & AD5933_STAT_DATA_VALID) {
+               int scan_count = bitmap_weight(indio_dev->active_scan_mask,
+                                              indio_dev->masklength);
+               ret = ad5933_i2c_read(st->client,
+                               test_bit(1, indio_dev->active_scan_mask) ?
+                               AD5933_REG_REAL_DATA : AD5933_REG_IMAG_DATA,
+                               scan_count * 2, (u8 *)buf);
+               if (ret)
+                       return;
+
+               if (scan_count == 2) {
+                       val[0] = be16_to_cpu(buf[0]);
+                       val[1] = be16_to_cpu(buf[1]);
+               } else {
+                       val[0] = be16_to_cpu(buf[0]);
+               }
+               iio_push_to_buffers(indio_dev, val);
+       } else {
+               /* no data available - try again later */
+               schedule_delayed_work(&st->work, st->poll_time_jiffies);
+               return;
+       }
+
+       if (status & AD5933_STAT_SWEEP_DONE) {
+               /*
+                * last sample received - power down do
+                * nothing until the ring enable is toggled
+                */
+               ad5933_cmd(st, AD5933_CTRL_POWER_DOWN);
+       } else {
+               /* we just received a valid datum, move on to the next */
+               ad5933_cmd(st, AD5933_CTRL_INC_FREQ);
+               schedule_delayed_work(&st->work, st->poll_time_jiffies);
+       }
+}
+
+static int ad5933_probe(struct i2c_client *client,
+                       const struct i2c_device_id *id)
+{
+       int ret;
+       struct ad5933_state *st;
+       struct iio_dev *indio_dev;
+       unsigned long ext_clk_hz = 0;
+
+       indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
+       if (!indio_dev)
+               return -ENOMEM;
+
+       st = iio_priv(indio_dev);
+       i2c_set_clientdata(client, indio_dev);
+       st->client = client;
+
+       mutex_init(&st->lock);
+
+       st->reg = devm_regulator_get(&client->dev, "vdd");
+       if (IS_ERR(st->reg))
+               return PTR_ERR(st->reg);
+
+       ret = regulator_enable(st->reg);
+       if (ret) {
+               dev_err(&client->dev, "Failed to enable specified VDD 
supply\n");
+               return ret;
+       }
+       ret = regulator_get_voltage(st->reg);
+
+       if (ret < 0)
+               goto error_disable_reg;
+
+       st->vref_mv = ret / 1000;
+
+       st->mclk = devm_clk_get(&client->dev, "mclk");
+       if (IS_ERR(st->mclk) && PTR_ERR(st->mclk) != -ENOENT) {
+               ret = PTR_ERR(st->mclk);
+               goto error_disable_reg;
+       }
+
+       if (!IS_ERR(st->mclk)) {
+               ret = clk_prepare_enable(st->mclk);
+               if (ret < 0)
+                       goto error_disable_reg;
+               ext_clk_hz = clk_get_rate(st->mclk);
+       }
+
+       if (ext_clk_hz) {
+               st->mclk_hz = ext_clk_hz;
+               st->ctrl_lb = AD5933_CTRL_EXT_SYSCLK;
+       } else {
+               st->mclk_hz = AD5933_INT_OSC_FREQ_Hz;
+               st->ctrl_lb = AD5933_CTRL_INT_SYSCLK;
+       }
+
+       ad5933_calc_out_ranges(st);
+       INIT_DELAYED_WORK(&st->work, ad5933_work);
+       st->poll_time_jiffies = msecs_to_jiffies(AD5933_POLL_TIME_ms);
+
+       indio_dev->dev.parent = &client->dev;
+       indio_dev->info = &ad5933_info;
+       indio_dev->name = id->name;
+       indio_dev->modes = (INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE);
+       indio_dev->channels = ad5933_channels;
+       indio_dev->num_channels = ARRAY_SIZE(ad5933_channels);
+
+       ret = ad5933_register_ring_funcs_and_init(indio_dev);
+       if (ret)
+               goto error_disable_mclk;
+
+       ret = ad5933_setup(st);
+       if (ret)
+               goto error_unreg_ring;
+
+       ret = iio_device_register(indio_dev);
+       if (ret)
+               goto error_unreg_ring;
+
+       return 0;
+
+error_unreg_ring:
+       iio_kfifo_free(indio_dev->buffer);
+error_disable_mclk:
+       clk_disable_unprepare(st->mclk);
+error_disable_reg:
+       regulator_disable(st->reg);
+
+       return ret;
+}
+
+static int ad5933_remove(struct i2c_client *client)
+{
+       struct iio_dev *indio_dev = i2c_get_clientdata(client);
+       struct ad5933_state *st = iio_priv(indio_dev);
+
+       iio_device_unregister(indio_dev);
+       iio_kfifo_free(indio_dev->buffer);
+       regulator_disable(st->reg);
+       clk_disable_unprepare(st->mclk);
+
+       return 0;
+}
+
+static const struct i2c_device_id ad5933_id[] = {
+       { "ad5933", 0 },
+       { "ad5934", 0 },
+       {}
+};
+
+MODULE_DEVICE_TABLE(i2c, ad5933_id);
+
+static const struct of_device_id ad5933_of_match[] = {
+       { .compatible = "adi,ad5933" },
+       { .compatible = "adi,ad5934" },
+       { },
+};
+
+MODULE_DEVICE_TABLE(of, ad5933_of_match);
+
+static struct i2c_driver ad5933_driver = {
+       .driver = {
+               .name = "ad5933",
+               .of_match_table = ad5933_of_match,
+       },
+       .probe = ad5933_probe,
+       .remove = ad5933_remove,
+       .id_table = ad5933_id,
+};
+module_i2c_driver(ad5933_driver);
+
+MODULE_AUTHOR("Michael Hennerich <michael.henner...@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD5933 Impedance Conv. Network Analyzer");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/staging/iio/impedance-analyzer/Kconfig 
b/drivers/staging/iio/impedance-analyzer/Kconfig
deleted file mode 100644
index b9a679cdd146..000000000000
--- a/drivers/staging/iio/impedance-analyzer/Kconfig
+++ /dev/null
@@ -1,18 +0,0 @@
-#
-# Impedance Converter, Network Analyzer drivers
-#
-menu "Network Analyzer, Impedance Converters"
-
-config AD5933
-       tristate "Analog Devices AD5933, AD5934 driver"
-       depends on I2C
-       select IIO_BUFFER
-       select IIO_KFIFO_BUF
-       help
-         Say yes here to build support for Analog Devices Impedance Converter,
-         Network Analyzer, AD5933/4.
-
-         To compile this driver as a module, choose M here: the
-         module will be called ad5933.
-
-endmenu
diff --git a/drivers/staging/iio/impedance-analyzer/Makefile 
b/drivers/staging/iio/impedance-analyzer/Makefile
deleted file mode 100644
index 7604d786583e..000000000000
--- a/drivers/staging/iio/impedance-analyzer/Makefile
+++ /dev/null
@@ -1,5 +0,0 @@
-#
-# Makefile for Impedance Converter, Network Analyzer drivers
-#
-
-obj-$(CONFIG_AD5933) += ad5933.o
diff --git a/drivers/staging/iio/impedance-analyzer/ad5933.c 
b/drivers/staging/iio/impedance-analyzer/ad5933.c
deleted file mode 100644
index d75bdfbf93de..000000000000
--- a/drivers/staging/iio/impedance-analyzer/ad5933.c
+++ /dev/null
@@ -1,811 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * AD5933 AD5934 Impedance Converter, Network Analyzer
- *
- * Copyright 2011 Analog Devices Inc.
- */
-
-#include <linux/clk.h>
-#include <linux/delay.h>
-#include <linux/device.h>
-#include <linux/err.h>
-#include <linux/i2c.h>
-#include <linux/interrupt.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/regulator/consumer.h>
-#include <linux/sysfs.h>
-#include <linux/types.h>
-
-#include <linux/iio/buffer.h>
-#include <linux/iio/iio.h>
-#include <linux/iio/kfifo_buf.h>
-#include <linux/iio/sysfs.h>
-
-/* AD5933/AD5934 Registers */
-#define AD5933_REG_CONTROL_HB          0x80    /* R/W, 1 byte */
-#define AD5933_REG_CONTROL_LB          0x81    /* R/W, 1 byte */
-#define AD5933_REG_FREQ_START          0x82    /* R/W, 3 bytes */
-#define AD5933_REG_FREQ_INC            0x85    /* R/W, 3 bytes */
-#define AD5933_REG_INC_NUM             0x88    /* R/W, 2 bytes, 9 bit */
-#define AD5933_REG_SETTLING_CYCLES     0x8A    /* R/W, 2 bytes */
-#define AD5933_REG_STATUS              0x8F    /* R, 1 byte */
-#define AD5933_REG_TEMP_DATA           0x92    /* R, 2 bytes*/
-#define AD5933_REG_REAL_DATA           0x94    /* R, 2 bytes*/
-#define AD5933_REG_IMAG_DATA           0x96    /* R, 2 bytes*/
-
-/* AD5933_REG_CONTROL_HB Bits */
-#define AD5933_CTRL_INIT_START_FREQ    (0x1 << 4)
-#define AD5933_CTRL_START_SWEEP                (0x2 << 4)
-#define AD5933_CTRL_INC_FREQ           (0x3 << 4)
-#define AD5933_CTRL_REPEAT_FREQ                (0x4 << 4)
-#define AD5933_CTRL_MEASURE_TEMP       (0x9 << 4)
-#define AD5933_CTRL_POWER_DOWN         (0xA << 4)
-#define AD5933_CTRL_STANDBY            (0xB << 4)
-
-#define AD5933_CTRL_RANGE_2000mVpp     (0x0 << 1)
-#define AD5933_CTRL_RANGE_200mVpp      (0x1 << 1)
-#define AD5933_CTRL_RANGE_400mVpp      (0x2 << 1)
-#define AD5933_CTRL_RANGE_1000mVpp     (0x3 << 1)
-#define AD5933_CTRL_RANGE(x)           ((x) << 1)
-
-#define AD5933_CTRL_PGA_GAIN_1         (0x1 << 0)
-#define AD5933_CTRL_PGA_GAIN_5         (0x0 << 0)
-
-/* AD5933_REG_CONTROL_LB Bits */
-#define AD5933_CTRL_RESET              (0x1 << 4)
-#define AD5933_CTRL_INT_SYSCLK         (0x0 << 3)
-#define AD5933_CTRL_EXT_SYSCLK         (0x1 << 3)
-
-/* AD5933_REG_STATUS Bits */
-#define AD5933_STAT_TEMP_VALID         (0x1 << 0)
-#define AD5933_STAT_DATA_VALID         (0x1 << 1)
-#define AD5933_STAT_SWEEP_DONE         (0x1 << 2)
-
-/* I2C Block Commands */
-#define AD5933_I2C_BLOCK_WRITE         0xA0
-#define AD5933_I2C_BLOCK_READ          0xA1
-#define AD5933_I2C_ADDR_POINTER                0xB0
-
-/* Device Specs */
-#define AD5933_INT_OSC_FREQ_Hz         16776000
-#define AD5933_MAX_OUTPUT_FREQ_Hz      100000
-#define AD5933_MAX_RETRIES             100
-
-#define AD5933_OUT_RANGE               1
-#define AD5933_OUT_RANGE_AVAIL         2
-#define AD5933_OUT_SETTLING_CYCLES     3
-#define AD5933_IN_PGA_GAIN             4
-#define AD5933_IN_PGA_GAIN_AVAIL       5
-#define AD5933_FREQ_POINTS             6
-
-#define AD5933_POLL_TIME_ms            10
-#define AD5933_INIT_EXCITATION_TIME_ms 100
-
-struct ad5933_state {
-       struct i2c_client               *client;
-       struct regulator                *reg;
-       struct clk                      *mclk;
-       struct delayed_work             work;
-       struct mutex                    lock; /* Protect sensor state */
-       unsigned long                   mclk_hz;
-       unsigned char                   ctrl_hb;
-       unsigned char                   ctrl_lb;
-       unsigned int                    range_avail[4];
-       unsigned short                  vref_mv;
-       unsigned short                  settling_cycles;
-       unsigned short                  freq_points;
-       unsigned int                    freq_start;
-       unsigned int                    freq_inc;
-       unsigned int                    state;
-       unsigned int                    poll_time_jiffies;
-};
-
-#define AD5933_CHANNEL(_type, _extend_name, _info_mask_separate, _address, \
-               _scan_index, _realbits) { \
-       .type = (_type), \
-       .extend_name = (_extend_name), \
-       .info_mask_separate = (_info_mask_separate), \
-       .address = (_address), \
-       .scan_index = (_scan_index), \
-       .scan_type = { \
-               .sign = 's', \
-               .realbits = (_realbits), \
-               .storagebits = 16, \
-       }, \
-}
-
-static const struct iio_chan_spec ad5933_channels[] = {
-       AD5933_CHANNEL(IIO_TEMP, NULL, BIT(IIO_CHAN_INFO_RAW) |
-               BIT(IIO_CHAN_INFO_SCALE), AD5933_REG_TEMP_DATA, -1, 14),
-       /* Ring Channels */
-       AD5933_CHANNEL(IIO_VOLTAGE, "real", 0, AD5933_REG_REAL_DATA, 0, 16),
-       AD5933_CHANNEL(IIO_VOLTAGE, "imag", 0, AD5933_REG_IMAG_DATA, 1, 16),
-};
-
-static int ad5933_i2c_write(struct i2c_client *client, u8 reg, u8 len, u8 
*data)
-{
-       int ret;
-
-       while (len--) {
-               ret = i2c_smbus_write_byte_data(client, reg++, *data++);
-               if (ret < 0) {
-                       dev_err(&client->dev, "I2C write error\n");
-                       return ret;
-               }
-       }
-       return 0;
-}
-
-static int ad5933_i2c_read(struct i2c_client *client, u8 reg, u8 len, u8 *data)
-{
-       int ret;
-
-       while (len--) {
-               ret = i2c_smbus_read_byte_data(client, reg++);
-               if (ret < 0) {
-                       dev_err(&client->dev, "I2C read error\n");
-                       return ret;
-               }
-               *data++ = ret;
-       }
-       return 0;
-}
-
-static int ad5933_cmd(struct ad5933_state *st, unsigned char cmd)
-{
-       unsigned char dat = st->ctrl_hb | cmd;
-
-       return ad5933_i2c_write(st->client,
-                       AD5933_REG_CONTROL_HB, 1, &dat);
-}
-
-static int ad5933_reset(struct ad5933_state *st)
-{
-       unsigned char dat = st->ctrl_lb | AD5933_CTRL_RESET;
-
-       return ad5933_i2c_write(st->client,
-                       AD5933_REG_CONTROL_LB, 1, &dat);
-}
-
-static int ad5933_wait_busy(struct ad5933_state *st, unsigned char event)
-{
-       unsigned char val, timeout = AD5933_MAX_RETRIES;
-       int ret;
-
-       while (timeout--) {
-               ret =  ad5933_i2c_read(st->client, AD5933_REG_STATUS, 1, &val);
-               if (ret < 0)
-                       return ret;
-               if (val & event)
-                       return val;
-               cpu_relax();
-               mdelay(1);
-       }
-
-       return -EAGAIN;
-}
-
-static int ad5933_set_freq(struct ad5933_state *st,
-                          unsigned int reg, unsigned long freq)
-{
-       unsigned long long freqreg;
-       union {
-               __be32 d32;
-               u8 d8[4];
-       } dat;
-
-       freqreg = (u64)freq * (u64)(1 << 27);
-       do_div(freqreg, st->mclk_hz / 4);
-
-       switch (reg) {
-       case AD5933_REG_FREQ_START:
-               st->freq_start = freq;
-               break;
-       case AD5933_REG_FREQ_INC:
-               st->freq_inc = freq;
-               break;
-       default:
-               return -EINVAL;
-       }
-
-       dat.d32 = cpu_to_be32(freqreg);
-       return ad5933_i2c_write(st->client, reg, 3, &dat.d8[1]);
-}
-
-static int ad5933_setup(struct ad5933_state *st)
-{
-       __be16 dat;
-       int ret;
-
-       ret = ad5933_reset(st);
-       if (ret < 0)
-               return ret;
-
-       ret = ad5933_set_freq(st, AD5933_REG_FREQ_START, 10000);
-       if (ret < 0)
-               return ret;
-
-       ret = ad5933_set_freq(st, AD5933_REG_FREQ_INC, 200);
-       if (ret < 0)
-               return ret;
-
-       st->settling_cycles = 10;
-       dat = cpu_to_be16(st->settling_cycles);
-
-       ret = ad5933_i2c_write(st->client,
-                              AD5933_REG_SETTLING_CYCLES,
-                              2, (u8 *)&dat);
-       if (ret < 0)
-               return ret;
-
-       st->freq_points = 100;
-       dat = cpu_to_be16(st->freq_points);
-
-       return ad5933_i2c_write(st->client, AD5933_REG_INC_NUM, 2, (u8 *)&dat);
-}
-
-static void ad5933_calc_out_ranges(struct ad5933_state *st)
-{
-       int i;
-       unsigned int normalized_3v3[4] = {1980, 198, 383, 970};
-
-       for (i = 0; i < 4; i++)
-               st->range_avail[i] = normalized_3v3[i] * st->vref_mv / 3300;
-}
-
-/*
- * handles: AD5933_REG_FREQ_START and AD5933_REG_FREQ_INC
- */
-
-static ssize_t ad5933_show_frequency(struct device *dev,
-                                    struct device_attribute *attr,
-                                    char *buf)
-{
-       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-       struct ad5933_state *st = iio_priv(indio_dev);
-       struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
-       int ret;
-       unsigned long long freqreg;
-       union {
-               __be32 d32;
-               u8 d8[4];
-       } dat;
-
-       ret = iio_device_claim_direct_mode(indio_dev);
-       if (ret)
-               return ret;
-       ret = ad5933_i2c_read(st->client, this_attr->address, 3, &dat.d8[1]);
-       iio_device_release_direct_mode(indio_dev);
-       if (ret < 0)
-               return ret;
-
-       freqreg = be32_to_cpu(dat.d32) & 0xFFFFFF;
-
-       freqreg = (u64)freqreg * (u64)(st->mclk_hz / 4);
-       do_div(freqreg, 1 << 27);
-
-       return sprintf(buf, "%d\n", (int)freqreg);
-}
-
-static ssize_t ad5933_store_frequency(struct device *dev,
-                                     struct device_attribute *attr,
-                                     const char *buf,
-                                     size_t len)
-{
-       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-       struct ad5933_state *st = iio_priv(indio_dev);
-       struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
-       unsigned long val;
-       int ret;
-
-       ret = kstrtoul(buf, 10, &val);
-       if (ret)
-               return ret;
-
-       if (val > AD5933_MAX_OUTPUT_FREQ_Hz)
-               return -EINVAL;
-
-       ret = iio_device_claim_direct_mode(indio_dev);
-       if (ret)
-               return ret;
-       ret = ad5933_set_freq(st, this_attr->address, val);
-       iio_device_release_direct_mode(indio_dev);
-
-       return ret ? ret : len;
-}
-
-static IIO_DEVICE_ATTR(out_voltage0_freq_start, 0644,
-                       ad5933_show_frequency,
-                       ad5933_store_frequency,
-                       AD5933_REG_FREQ_START);
-
-static IIO_DEVICE_ATTR(out_voltage0_freq_increment, 0644,
-                       ad5933_show_frequency,
-                       ad5933_store_frequency,
-                       AD5933_REG_FREQ_INC);
-
-static ssize_t ad5933_show(struct device *dev,
-                          struct device_attribute *attr,
-                          char *buf)
-{
-       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-       struct ad5933_state *st = iio_priv(indio_dev);
-       struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
-       int ret = 0, len = 0;
-
-       mutex_lock(&st->lock);
-       switch ((u32)this_attr->address) {
-       case AD5933_OUT_RANGE:
-               len = sprintf(buf, "%u\n",
-                             st->range_avail[(st->ctrl_hb >> 1) & 0x3]);
-               break;
-       case AD5933_OUT_RANGE_AVAIL:
-               len = sprintf(buf, "%u %u %u %u\n", st->range_avail[0],
-                             st->range_avail[3], st->range_avail[2],
-                             st->range_avail[1]);
-               break;
-       case AD5933_OUT_SETTLING_CYCLES:
-               len = sprintf(buf, "%d\n", st->settling_cycles);
-               break;
-       case AD5933_IN_PGA_GAIN:
-               len = sprintf(buf, "%s\n",
-                             (st->ctrl_hb & AD5933_CTRL_PGA_GAIN_1) ?
-                             "1" : "0.2");
-               break;
-       case AD5933_IN_PGA_GAIN_AVAIL:
-               len = sprintf(buf, "1 0.2\n");
-               break;
-       case AD5933_FREQ_POINTS:
-               len = sprintf(buf, "%d\n", st->freq_points);
-               break;
-       default:
-               ret = -EINVAL;
-       }
-
-       mutex_unlock(&st->lock);
-       return ret ? ret : len;
-}
-
-static ssize_t ad5933_store(struct device *dev,
-                           struct device_attribute *attr,
-                           const char *buf,
-                           size_t len)
-{
-       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-       struct ad5933_state *st = iio_priv(indio_dev);
-       struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
-       u16 val;
-       int i, ret = 0;
-       __be16 dat;
-
-       if (this_attr->address != AD5933_IN_PGA_GAIN) {
-               ret = kstrtou16(buf, 10, &val);
-               if (ret)
-                       return ret;
-       }
-
-       ret = iio_device_claim_direct_mode(indio_dev);
-       if (ret)
-               return ret;
-       mutex_lock(&st->lock);
-       switch ((u32)this_attr->address) {
-       case AD5933_OUT_RANGE:
-               ret = -EINVAL;
-               for (i = 0; i < 4; i++)
-                       if (val == st->range_avail[i]) {
-                               st->ctrl_hb &= ~AD5933_CTRL_RANGE(0x3);
-                               st->ctrl_hb |= AD5933_CTRL_RANGE(i);
-                               ret = ad5933_cmd(st, 0);
-                               break;
-                       }
-               break;
-       case AD5933_IN_PGA_GAIN:
-               if (sysfs_streq(buf, "1")) {
-                       st->ctrl_hb |= AD5933_CTRL_PGA_GAIN_1;
-               } else if (sysfs_streq(buf, "0.2")) {
-                       st->ctrl_hb &= ~AD5933_CTRL_PGA_GAIN_1;
-               } else {
-                       ret = -EINVAL;
-                       break;
-               }
-               ret = ad5933_cmd(st, 0);
-               break;
-       case AD5933_OUT_SETTLING_CYCLES:
-               val = clamp(val, (u16)0, (u16)0x7FF);
-               st->settling_cycles = val;
-
-               /* 2x, 4x handling, see datasheet */
-               if (val > 1022)
-                       val = (val >> 2) | (3 << 9);
-               else if (val > 511)
-                       val = (val >> 1) | (1 << 9);
-
-               dat = cpu_to_be16(val);
-               ret = ad5933_i2c_write(st->client,
-                                      AD5933_REG_SETTLING_CYCLES,
-                                      2, (u8 *)&dat);
-               break;
-       case AD5933_FREQ_POINTS:
-               val = clamp(val, (u16)0, (u16)511);
-               st->freq_points = val;
-
-               dat = cpu_to_be16(val);
-               ret = ad5933_i2c_write(st->client, AD5933_REG_INC_NUM, 2,
-                                      (u8 *)&dat);
-               break;
-       default:
-               ret = -EINVAL;
-       }
-
-       mutex_unlock(&st->lock);
-       iio_device_release_direct_mode(indio_dev);
-       return ret ? ret : len;
-}
-
-static IIO_DEVICE_ATTR(out_voltage0_scale, 0644,
-                       ad5933_show,
-                       ad5933_store,
-                       AD5933_OUT_RANGE);
-
-static IIO_DEVICE_ATTR(out_voltage0_scale_available, 0444,
-                       ad5933_show,
-                       NULL,
-                       AD5933_OUT_RANGE_AVAIL);
-
-static IIO_DEVICE_ATTR(in_voltage0_scale, 0644,
-                       ad5933_show,
-                       ad5933_store,
-                       AD5933_IN_PGA_GAIN);
-
-static IIO_DEVICE_ATTR(in_voltage0_scale_available, 0444,
-                       ad5933_show,
-                       NULL,
-                       AD5933_IN_PGA_GAIN_AVAIL);
-
-static IIO_DEVICE_ATTR(out_voltage0_freq_points, 0644,
-                       ad5933_show,
-                       ad5933_store,
-                       AD5933_FREQ_POINTS);
-
-static IIO_DEVICE_ATTR(out_voltage0_settling_cycles, 0644,
-                       ad5933_show,
-                       ad5933_store,
-                       AD5933_OUT_SETTLING_CYCLES);
-
-/*
- * note:
- * ideally we would handle the scale attributes via the iio_info
- * (read|write)_raw methods, however this part is a untypical since we
- * don't create dedicated sysfs channel attributes for out0 and in0.
- */
-static struct attribute *ad5933_attributes[] = {
-       &iio_dev_attr_out_voltage0_scale.dev_attr.attr,
-       &iio_dev_attr_out_voltage0_scale_available.dev_attr.attr,
-       &iio_dev_attr_out_voltage0_freq_start.dev_attr.attr,
-       &iio_dev_attr_out_voltage0_freq_increment.dev_attr.attr,
-       &iio_dev_attr_out_voltage0_freq_points.dev_attr.attr,
-       &iio_dev_attr_out_voltage0_settling_cycles.dev_attr.attr,
-       &iio_dev_attr_in_voltage0_scale.dev_attr.attr,
-       &iio_dev_attr_in_voltage0_scale_available.dev_attr.attr,
-       NULL
-};
-
-static const struct attribute_group ad5933_attribute_group = {
-       .attrs = ad5933_attributes,
-};
-
-static int ad5933_read_raw(struct iio_dev *indio_dev,
-                          struct iio_chan_spec const *chan,
-                          int *val,
-                          int *val2,
-                          long m)
-{
-       struct ad5933_state *st = iio_priv(indio_dev);
-       __be16 dat;
-       int ret;
-
-       switch (m) {
-       case IIO_CHAN_INFO_RAW:
-               ret = iio_device_claim_direct_mode(indio_dev);
-               if (ret)
-                       return ret;
-               ret = ad5933_cmd(st, AD5933_CTRL_MEASURE_TEMP);
-               if (ret < 0)
-                       goto out;
-               ret = ad5933_wait_busy(st, AD5933_STAT_TEMP_VALID);
-               if (ret < 0)
-                       goto out;
-
-               ret = ad5933_i2c_read(st->client,
-                                     AD5933_REG_TEMP_DATA,
-                                     2, (u8 *)&dat);
-               if (ret < 0)
-                       goto out;
-               iio_device_release_direct_mode(indio_dev);
-               *val = sign_extend32(be16_to_cpu(dat), 13);
-
-               return IIO_VAL_INT;
-       case IIO_CHAN_INFO_SCALE:
-               *val = 1000;
-               *val2 = 5;
-               return IIO_VAL_FRACTIONAL_LOG2;
-       }
-
-       return -EINVAL;
-out:
-       iio_device_release_direct_mode(indio_dev);
-       return ret;
-}
-
-static const struct iio_info ad5933_info = {
-       .read_raw = ad5933_read_raw,
-       .attrs = &ad5933_attribute_group,
-};
-
-static int ad5933_ring_preenable(struct iio_dev *indio_dev)
-{
-       struct ad5933_state *st = iio_priv(indio_dev);
-       int ret;
-
-       if (bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength))
-               return -EINVAL;
-
-       ret = ad5933_reset(st);
-       if (ret < 0)
-               return ret;
-
-       ret = ad5933_cmd(st, AD5933_CTRL_STANDBY);
-       if (ret < 0)
-               return ret;
-
-       ret = ad5933_cmd(st, AD5933_CTRL_INIT_START_FREQ);
-       if (ret < 0)
-               return ret;
-
-       st->state = AD5933_CTRL_INIT_START_FREQ;
-
-       return 0;
-}
-
-static int ad5933_ring_postenable(struct iio_dev *indio_dev)
-{
-       struct ad5933_state *st = iio_priv(indio_dev);
-
-       /*
-        * AD5933_CTRL_INIT_START_FREQ:
-        * High Q complex circuits require a long time to reach steady state.
-        * To facilitate the measurement of such impedances, this mode allows
-        * the user full control of the settling time requirement before
-        * entering start frequency sweep mode where the impedance measurement
-        * takes place. In this mode the impedance is excited with the
-        * programmed start frequency (ad5933_ring_preenable),
-        * but no measurement takes place.
-        */
-
-       schedule_delayed_work(&st->work,
-                             msecs_to_jiffies(AD5933_INIT_EXCITATION_TIME_ms));
-       return 0;
-}
-
-static int ad5933_ring_postdisable(struct iio_dev *indio_dev)
-{
-       struct ad5933_state *st = iio_priv(indio_dev);
-
-       cancel_delayed_work_sync(&st->work);
-       return ad5933_cmd(st, AD5933_CTRL_POWER_DOWN);
-}
-
-static const struct iio_buffer_setup_ops ad5933_ring_setup_ops = {
-       .preenable = ad5933_ring_preenable,
-       .postenable = ad5933_ring_postenable,
-       .postdisable = ad5933_ring_postdisable,
-};
-
-static int ad5933_register_ring_funcs_and_init(struct iio_dev *indio_dev)
-{
-       struct iio_buffer *buffer;
-
-       buffer = iio_kfifo_allocate();
-       if (!buffer)
-               return -ENOMEM;
-
-       iio_device_attach_buffer(indio_dev, buffer);
-
-       /* Ring buffer functions - here trigger setup related */
-       indio_dev->setup_ops = &ad5933_ring_setup_ops;
-
-       return 0;
-}
-
-static void ad5933_work(struct work_struct *work)
-{
-       struct ad5933_state *st = container_of(work,
-               struct ad5933_state, work.work);
-       struct iio_dev *indio_dev = i2c_get_clientdata(st->client);
-       __be16 buf[2];
-       int val[2];
-       unsigned char status;
-       int ret;
-
-       if (st->state == AD5933_CTRL_INIT_START_FREQ) {
-               /* start sweep */
-               ad5933_cmd(st, AD5933_CTRL_START_SWEEP);
-               st->state = AD5933_CTRL_START_SWEEP;
-               schedule_delayed_work(&st->work, st->poll_time_jiffies);
-               return;
-       }
-
-       ret = ad5933_i2c_read(st->client, AD5933_REG_STATUS, 1, &status);
-       if (ret)
-               return;
-
-       if (status & AD5933_STAT_DATA_VALID) {
-               int scan_count = bitmap_weight(indio_dev->active_scan_mask,
-                                              indio_dev->masklength);
-               ret = ad5933_i2c_read(st->client,
-                               test_bit(1, indio_dev->active_scan_mask) ?
-                               AD5933_REG_REAL_DATA : AD5933_REG_IMAG_DATA,
-                               scan_count * 2, (u8 *)buf);
-               if (ret)
-                       return;
-
-               if (scan_count == 2) {
-                       val[0] = be16_to_cpu(buf[0]);
-                       val[1] = be16_to_cpu(buf[1]);
-               } else {
-                       val[0] = be16_to_cpu(buf[0]);
-               }
-               iio_push_to_buffers(indio_dev, val);
-       } else {
-               /* no data available - try again later */
-               schedule_delayed_work(&st->work, st->poll_time_jiffies);
-               return;
-       }
-
-       if (status & AD5933_STAT_SWEEP_DONE) {
-               /*
-                * last sample received - power down do
-                * nothing until the ring enable is toggled
-                */
-               ad5933_cmd(st, AD5933_CTRL_POWER_DOWN);
-       } else {
-               /* we just received a valid datum, move on to the next */
-               ad5933_cmd(st, AD5933_CTRL_INC_FREQ);
-               schedule_delayed_work(&st->work, st->poll_time_jiffies);
-       }
-}
-
-static int ad5933_probe(struct i2c_client *client,
-                       const struct i2c_device_id *id)
-{
-       int ret;
-       struct ad5933_state *st;
-       struct iio_dev *indio_dev;
-       unsigned long ext_clk_hz = 0;
-
-       indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
-       if (!indio_dev)
-               return -ENOMEM;
-
-       st = iio_priv(indio_dev);
-       i2c_set_clientdata(client, indio_dev);
-       st->client = client;
-
-       mutex_init(&st->lock);
-
-       st->reg = devm_regulator_get(&client->dev, "vdd");
-       if (IS_ERR(st->reg))
-               return PTR_ERR(st->reg);
-
-       ret = regulator_enable(st->reg);
-       if (ret) {
-               dev_err(&client->dev, "Failed to enable specified VDD 
supply\n");
-               return ret;
-       }
-       ret = regulator_get_voltage(st->reg);
-
-       if (ret < 0)
-               goto error_disable_reg;
-
-       st->vref_mv = ret / 1000;
-
-       st->mclk = devm_clk_get(&client->dev, "mclk");
-       if (IS_ERR(st->mclk) && PTR_ERR(st->mclk) != -ENOENT) {
-               ret = PTR_ERR(st->mclk);
-               goto error_disable_reg;
-       }
-
-       if (!IS_ERR(st->mclk)) {
-               ret = clk_prepare_enable(st->mclk);
-               if (ret < 0)
-                       goto error_disable_reg;
-               ext_clk_hz = clk_get_rate(st->mclk);
-       }
-
-       if (ext_clk_hz) {
-               st->mclk_hz = ext_clk_hz;
-               st->ctrl_lb = AD5933_CTRL_EXT_SYSCLK;
-       } else {
-               st->mclk_hz = AD5933_INT_OSC_FREQ_Hz;
-               st->ctrl_lb = AD5933_CTRL_INT_SYSCLK;
-       }
-
-       ad5933_calc_out_ranges(st);
-       INIT_DELAYED_WORK(&st->work, ad5933_work);
-       st->poll_time_jiffies = msecs_to_jiffies(AD5933_POLL_TIME_ms);
-
-       indio_dev->dev.parent = &client->dev;
-       indio_dev->info = &ad5933_info;
-       indio_dev->name = id->name;
-       indio_dev->modes = (INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE);
-       indio_dev->channels = ad5933_channels;
-       indio_dev->num_channels = ARRAY_SIZE(ad5933_channels);
-
-       ret = ad5933_register_ring_funcs_and_init(indio_dev);
-       if (ret)
-               goto error_disable_mclk;
-
-       ret = ad5933_setup(st);
-       if (ret)
-               goto error_unreg_ring;
-
-       ret = iio_device_register(indio_dev);
-       if (ret)
-               goto error_unreg_ring;
-
-       return 0;
-
-error_unreg_ring:
-       iio_kfifo_free(indio_dev->buffer);
-error_disable_mclk:
-       clk_disable_unprepare(st->mclk);
-error_disable_reg:
-       regulator_disable(st->reg);
-
-       return ret;
-}
-
-static int ad5933_remove(struct i2c_client *client)
-{
-       struct iio_dev *indio_dev = i2c_get_clientdata(client);
-       struct ad5933_state *st = iio_priv(indio_dev);
-
-       iio_device_unregister(indio_dev);
-       iio_kfifo_free(indio_dev->buffer);
-       regulator_disable(st->reg);
-       clk_disable_unprepare(st->mclk);
-
-       return 0;
-}
-
-static const struct i2c_device_id ad5933_id[] = {
-       { "ad5933", 0 },
-       { "ad5934", 0 },
-       {}
-};
-
-MODULE_DEVICE_TABLE(i2c, ad5933_id);
-
-static const struct of_device_id ad5933_of_match[] = {
-       { .compatible = "adi,ad5933" },
-       { .compatible = "adi,ad5934" },
-       { },
-};
-
-MODULE_DEVICE_TABLE(of, ad5933_of_match);
-
-static struct i2c_driver ad5933_driver = {
-       .driver = {
-               .name = "ad5933",
-               .of_match_table = ad5933_of_match,
-       },
-       .probe = ad5933_probe,
-       .remove = ad5933_remove,
-       .id_table = ad5933_id,
-};
-module_i2c_driver(ad5933_driver);
-
-MODULE_AUTHOR("Michael Hennerich <michael.henner...@analog.com>");
-MODULE_DESCRIPTION("Analog Devices AD5933 Impedance Conv. Network Analyzer");
-MODULE_LICENSE("GPL v2");
-- 
2.20.1

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