From: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
The AD5933 is a high precision impedance converter system solution
that combines an on-board frequency generator with a 12-bit, 1 MSPS,
analog-to-digital converter (ADC). The frequency generator allows an
external complex impedance to be excited with a known frequency.
The response signal from the impedance is sampled by the on-board ADC
and a discrete Fourier transform (DFT) is processed by an on-chip DSP engine.
The DFT algorithm returns a real (R) and imaginary (I) data-word at each
output frequency.
Changes since V1:
Apply list review feedback:
Consistently use poll_time_jiffies.
Use be|le cpu endian helpers where applicable.
Add various comments.
Changes since V2:
Fix KernelVersion tag in Documentation.
Declare ad5933_default_pdata static.
Fix typos.
Signed-off-by: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
Acked-by: Jonathan Cameron <jic23@xxxxxxxxx>
---
.../sysfs-bus-iio-impedance-analyzer-ad5933 | 30 +
drivers/staging/iio/Kconfig | 1 +
drivers/staging/iio/Makefile | 1 +
drivers/staging/iio/impedance-analyzer/Kconfig | 16 +
drivers/staging/iio/impedance-analyzer/Makefile | 5 +
drivers/staging/iio/impedance-analyzer/ad5933.c | 818 ++++++++++++++++++++
drivers/staging/iio/impedance-analyzer/ad5933.h | 28 +
7 files changed, 899 insertions(+), 0 deletions(-)
create mode 100644 drivers/staging/iio/Documentation/sysfs-bus-iio-impedance-analyzer-ad5933
create mode 100644 drivers/staging/iio/impedance-analyzer/Kconfig
create mode 100644 drivers/staging/iio/impedance-analyzer/Makefile
create mode 100644 drivers/staging/iio/impedance-analyzer/ad5933.c
create mode 100644 drivers/staging/iio/impedance-analyzer/ad5933.h
diff --git a/drivers/staging/iio/Documentation/sysfs-bus-iio-impedance-analyzer-ad5933 b/drivers/staging/iio/Documentation/sysfs-bus-iio-impedance-analyzer-ad5933
new file mode 100644
index 0000000..79c7e88
--- /dev/null
+++ b/drivers/staging/iio/Documentation/sysfs-bus-iio-impedance-analyzer-ad5933
@@ -0,0 +1,30 @@
+What: /sys/bus/iio/devices/iio:deviceX/outY_freq_start
+KernelVersion: 3.1.0
+Contact: linux-iio@xxxxxxxxxxxxxxx
+Description:
+ Frequency sweep start frequency in Hz.
+
+What: /sys/bus/iio/devices/iio:deviceX/outY_freq_increment
+KernelVersion: 3.1.0
+Contact: linux-iio@xxxxxxxxxxxxxxx
+Description:
+ Frequency increment in Hz (step size) between consecutive
+ frequency points along the sweep.
+
+What: /sys/bus/iio/devices/iio:deviceX/outY_freq_points
+KernelVersion: 3.1.0
+Contact: linux-iio@xxxxxxxxxxxxxxx
+Description:
+ Number of frequency points (steps) in the frequency sweep.
+ This value, in conjunction with the outY_freq_start and the
+ outY_freq_increment, determines the frequency sweep range
+ for the sweep operation.
+
+What: /sys/bus/iio/devices/iio:deviceX/outY_settling_cycles
+KernelVersion: 3.1.0
+Contact: linux-iio@xxxxxxxxxxxxxxx
+Description:
+ Number of output excitation cycles (settling time cycles)
+ that are allowed to pass through the unknown impedance,
+ after each frequency increment, and before the ADC is triggered
+ to perform a conversion sequence of the response signal.
diff --git a/drivers/staging/iio/Kconfig b/drivers/staging/iio/Kconfig
index d329635..7526567 100644
--- a/drivers/staging/iio/Kconfig
+++ b/drivers/staging/iio/Kconfig
@@ -62,6 +62,7 @@ source "drivers/staging/iio/addac/Kconfig"
source "drivers/staging/iio/dac/Kconfig"
source "drivers/staging/iio/dds/Kconfig"
source "drivers/staging/iio/gyro/Kconfig"
+source "drivers/staging/iio/impedance-analyzer/Kconfig"
source "drivers/staging/iio/imu/Kconfig"
source "drivers/staging/iio/light/Kconfig"
source "drivers/staging/iio/magnetometer/Kconfig"
diff --git a/drivers/staging/iio/Makefile b/drivers/staging/iio/Makefile
index bb5c95c..eaff649 100644
--- a/drivers/staging/iio/Makefile
+++ b/drivers/staging/iio/Makefile
@@ -16,6 +16,7 @@ obj-y += addac/
obj-y += dac/
obj-y += dds/
obj-y += gyro/
+obj-y += impedance-analyzer/
obj-y += imu/
obj-y += light/
obj-y += magnetometer/
diff --git a/drivers/staging/iio/impedance-analyzer/Kconfig b/drivers/staging/iio/impedance-analyzer/Kconfig
new file mode 100644
index 0000000..9e91a9b
--- /dev/null
+++ b/drivers/staging/iio/impedance-analyzer/Kconfig
@@ -0,0 +1,16 @@
+#
+# Impedance Converter, Network Analyzer drivers
+#
+comment "Network Analyzer, Impedance Converters"
+
+config AD5933
+ tristate "Analog Devices AD5933, AD5934 driver"
+ depends on I2C
+ select IIO_RING_BUFFER
+ select IIO_SW_RING
+ help
+ Say yes here to build support for Analog Devices Impedance Converter,
+ Network Analyzer, AD5933/4, provides direct access via sysfs.
+
+ To compile this driver as a module, choose M here: the
+ module will be called ad5933.
diff --git a/drivers/staging/iio/impedance-analyzer/Makefile b/drivers/staging/iio/impedance-analyzer/Makefile
new file mode 100644
index 0000000..7604d78
--- /dev/null
+++ b/drivers/staging/iio/impedance-analyzer/Makefile
@@ -0,0 +1,5 @@
+#
+# 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
new file mode 100644
index 0000000..acc0e69
--- /dev/null
+++ b/drivers/staging/iio/impedance-analyzer/ad5933.c
@@ -0,0 +1,818 @@
+/*
+ * AD5933 AD5934 Impedance Converter, Network Analyzer
+ *
+ * Copyright 2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/sysfs.h>
+#include <linux/i2c.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <asm/div64.h>
+
+#include "../iio.h"
+#include "../sysfs.h"
+#include "../ring_generic.h"
+#include "../ring_sw.h"
+
+#include "ad5933.h"
+
+/* AD5933/AD5934 Registers */
+#define AD5933_REG_CONTROL_HB 0x80 /* R/W, 2 bytes */
+#define AD5933_REG_CONTROL_LB 0x81 /* R/W, 2 bytes */
+#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 ad5933_platform_data *pdata;
+ struct delayed_work work;
+ unsigned long mclk_hz;
+ unsigned char ctrl_hb;
+ unsigned char ctrl_lb;
+ unsigned range_avail[4];
+ unsigned short vref_mv;
+ unsigned short settling_cycles;
+ unsigned short freq_points;
+ unsigned freq_start;
+ unsigned freq_inc;
+ unsigned state;
+ unsigned poll_time_jiffies;
+};
+
+static struct ad5933_platform_data ad5933_default_pdata = {
+ .vref_mv = 3300,
+};
+
+static struct iio_chan_spec ad5933_channels[] = {
+ IIO_CHAN(IIO_TEMP, 0, 1, 1, NULL, 0, 0, 0,
+ 0, AD5933_REG_TEMP_DATA, IIO_ST('s', 14, 16, 0), 0),
+ /* Ring Channels */
+ IIO_CHAN(IIO_IN, 0, 1, 0, "real_raw", 0, 0,
+ (1 << IIO_CHAN_INFO_SCALE_SEPARATE),
+ AD5933_REG_REAL_DATA, 0, IIO_ST('s', 16, 16, 0), 0),
+ IIO_CHAN(IIO_IN, 0, 1, 0, "imag_raw", 0, 0,
+ (1 << IIO_CHAN_INFO_SCALE_SEPARATE),
+ AD5933_REG_IMAG_DATA, 1, IIO_ST('s', 16, 16, 0), 0),
+};
+
+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 reg, unsigned long freq)
+{
+ unsigned long long freqreg;
+ union {
+ u32 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)
+{
+ unsigned short 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 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 *dev_info = dev_get_drvdata(dev);
+ struct ad5933_state *st = iio_priv(dev_info);
+ struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+ int ret;
+ unsigned long long freqreg;
+ union {
+ u32 d32;
+ u8 d8[4];
+ } dat;
+
+ mutex_lock(&dev_info->mlock);
+ ret = ad5933_i2c_read(st->client, this_attr->address, 3, &dat.d8[1]);
+ mutex_unlock(&dev_info->mlock);
+ 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 *dev_info = dev_get_drvdata(dev);
+ struct ad5933_state *st = iio_priv(dev_info);
+ struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+ long val;
+ int ret;
+
+ ret = strict_strtoul(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ if (val > AD5933_MAX_OUTPUT_FREQ_Hz)
+ return -EINVAL;
+
+ mutex_lock(&dev_info->mlock);
+ ret = ad5933_set_freq(st, this_attr->address, val);
+ mutex_unlock(&dev_info->mlock);
+
+ return ret ? ret : len;
+}
+
+static IIO_DEVICE_ATTR(out0_freq_start, S_IRUGO | S_IWUSR,
+ ad5933_show_frequency,
+ ad5933_store_frequency,
+ AD5933_REG_FREQ_START);
+
+static IIO_DEVICE_ATTR(out0_freq_increment, S_IRUGO | S_IWUSR,
+ 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 *dev_info = dev_get_drvdata(dev);
+ struct ad5933_state *st = iio_priv(dev_info);
+ struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+ int ret = 0, len = 0;
+
+ mutex_lock(&dev_info->mlock);
+ switch (this_attr->address) {
+ case AD5933_OUT_RANGE:
+ len = sprintf(buf, "%d\n",
+ st->range_avail[(st->ctrl_hb >> 1) & 0x3]);
+ break;
+ case AD5933_OUT_RANGE_AVAIL:
+ len = sprintf(buf, "%d %d %d %d\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(&dev_info->mlock);
+ 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 *dev_info = dev_get_drvdata(dev);
+ struct ad5933_state *st = iio_priv(dev_info);
+ struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+ long val;
+ int i, ret = 0;
+ unsigned short dat;
+
+ if (this_attr->address != AD5933_IN_PGA_GAIN) {
+ ret = strict_strtol(buf, 10, &val);
+ if (ret)
+ return ret;
+ }
+
+ mutex_lock(&dev_info->mlock);
+ switch (this_attr->address) {
+ case AD5933_OUT_RANGE:
+ 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;
+ }
+ ret = -EINVAL;
+ 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, 0L, 0x7FFL);
+ st->settling_cycles = val;
+
+ /* 2x, 4x handling, see datasheet */
+ if (val > 511)
+ val = (val >> 1) | (1 << 9);
+ else if (val > 1022)
+ val = (val >> 2) | (3 << 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, 0L, 511L);
+ 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(&dev_info->mlock);
+ return ret ? ret : len;
+}
+
+static IIO_DEVICE_ATTR(out0_scale, S_IRUGO | S_IWUSR,
+ ad5933_show,
+ ad5933_store,
+ AD5933_OUT_RANGE);
+
+static IIO_DEVICE_ATTR(out0_scale_available, S_IRUGO,
+ ad5933_show,
+ NULL,
+ AD5933_OUT_RANGE_AVAIL);
+
+static IIO_DEVICE_ATTR(in0_scale, S_IRUGO | S_IWUSR,
+ ad5933_show,
+ ad5933_store,
+ AD5933_IN_PGA_GAIN);
+
+static IIO_DEVICE_ATTR(in0_scale_available, S_IRUGO,
+ ad5933_show,
+ NULL,
+ AD5933_IN_PGA_GAIN_AVAIL);
+
+static IIO_DEVICE_ATTR(out0_freq_points, S_IRUGO | S_IWUSR,
+ ad5933_show,
+ ad5933_store,
+ AD5933_FREQ_POINTS);
+
+static IIO_DEVICE_ATTR(out0_settling_cycles, S_IRUGO | S_IWUSR,
+ 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_out0_scale.dev_attr.attr,
+ &iio_dev_attr_out0_scale_available.dev_attr.attr,
+ &iio_dev_attr_out0_freq_start.dev_attr.attr,
+ &iio_dev_attr_out0_freq_increment.dev_attr.attr,
+ &iio_dev_attr_out0_freq_points.dev_attr.attr,
+ &iio_dev_attr_out0_settling_cycles.dev_attr.attr,
+ &iio_dev_attr_in0_scale.dev_attr.attr,
+ &iio_dev_attr_in0_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 *dev_info,
+ struct iio_chan_spec const *chan,
+ int *val,
+ int *val2,
+ long m)
+{
+ struct ad5933_state *st = iio_priv(dev_info);
+ unsigned short dat;
+ int ret = -EINVAL;
+
+ mutex_lock(&dev_info->mlock);
+ switch (m) {
+ case 0:
+ if (iio_ring_enabled(dev_info)) {
+ ret = -EBUSY;
+ goto out;
+ }
+ 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;
+ mutex_unlock(&dev_info->mlock);
+ ret = be16_to_cpu(dat);
+ /* Temp in Milli degrees Celsius */
+ if (ret < 8192)
+ *val = ret * 1000 / 32;
+ else
+ *val = (ret - 16384) * 1000 / 32;
+
+ return IIO_VAL_INT;
+ }
+
+out:
+ mutex_unlock(&dev_info->mlock);
+ return ret;
+}
+
+static const struct iio_info ad5933_info = {
+ .read_raw = &ad5933_read_raw,
+ .attrs = &ad5933_attribute_group,
+ .driver_module = THIS_MODULE,
+};
+
+static int ad5933_ring_preenable(struct iio_dev *indio_dev)
+{
+ struct ad5933_state *st = iio_priv(indio_dev);
+ struct iio_ring_buffer *ring = indio_dev->ring;
+ size_t d_size;
+ int ret;
+
+ if (!ring->scan_count)
+ return -EINVAL;
+
+ d_size = ring->scan_count *
+ ad5933_channels[1].scan_type.storagebits / 8;
+
+ if (indio_dev->ring->access->set_bytes_per_datum)
+ indio_dev->ring->access->set_bytes_per_datum(indio_dev->ring,
+ d_size);
+
+ 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_ring_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)
+{
+ indio_dev->ring = iio_sw_rb_allocate(indio_dev);
+ if (!indio_dev->ring)
+ return -ENOMEM;
+
+ /* Effectively select the ring buffer implementation */
+ indio_dev->ring->access = &ring_sw_access_funcs;
+
+ /* Ring buffer functions - here trigger setup related */
+ indio_dev->ring->setup_ops = &ad5933_ring_setup_ops;
+
+ indio_dev->modes |= INDIO_RING_HARDWARE_BUFFER;
+
+ 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);
+ struct iio_ring_buffer *ring = indio_dev->ring;
+ signed short buf[2];
+ unsigned char status;
+
+ mutex_lock(&indio_dev->mlock);
+ 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);
+ mutex_unlock(&indio_dev->mlock);
+ return;
+ }
+
+ ad5933_i2c_read(st->client, AD5933_REG_STATUS, 1, &status);
+
+ if (status & AD5933_STAT_DATA_VALID) {
+ ad5933_i2c_read(st->client,
+ (ring->scan_mask & (1 << 0)) ?
+ AD5933_REG_REAL_DATA : AD5933_REG_IMAG_DATA,
+ ring->scan_count * 2, (u8 *)buf);
+
+ if (ring->scan_count == 2) {
+ buf[0] = be16_to_cpu(buf[0]);
+ buf[1] = be16_to_cpu(buf[1]);
+ } else {
+ buf[0] = be16_to_cpu(buf[0]);
+ }
+ /* save datum to the ring */
+ ring->access->store_to(ring, (u8 *)buf, iio_get_time_ns());
+ } else {
+ /* no data available - try again later */
+ schedule_delayed_work(&st->work, st->poll_time_jiffies);
+ mutex_unlock(&indio_dev->mlock);
+ 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);
+ }
+
+ mutex_unlock(&indio_dev->mlock);
+}
+
+static int __devinit ad5933_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ int ret, regdone = 0, voltage_uv = 0;
+ struct ad5933_platform_data *pdata = client->dev.platform_data;
+ struct ad5933_state *st;
+ struct iio_dev *indio_dev = iio_allocate_device(sizeof(*st));
+ if (indio_dev == NULL)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+ i2c_set_clientdata(client, indio_dev);
+ st->client = client;
+
+ if (!pdata)
+ st->pdata = &ad5933_default_pdata;
+ else
+ st->pdata = pdata;
+
+ st->reg = regulator_get(&client->dev, "vcc");
+ if (!IS_ERR(st->reg)) {
+ ret = regulator_enable(st->reg);
+ if (ret)
+ goto error_put_reg;
+ voltage_uv = regulator_get_voltage(st->reg);
+ }
+
+ if (voltage_uv)
+ st->vref_mv = voltage_uv / 1000;
+ else
+ st->vref_mv = st->pdata->vref_mv;
+
+ if (st->pdata->ext_clk_Hz) {
+ st->mclk_hz = st->pdata->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_DIRECT_MODE;
+ indio_dev->channels = ad5933_channels;
+ indio_dev->num_channels = 1; /* only register temp0_input */
+
+ ret = ad5933_register_ring_funcs_and_init(indio_dev);
+ if (ret)
+ goto error_disable_reg;
+
+ ret = iio_device_register(indio_dev);
+ if (ret)
+ goto error_unreg_ring;
+ regdone = 1;
+
+ /* skip temp0_input, register in0_(real|imag)_raw */
+ ret = iio_ring_buffer_register_ex(indio_dev->ring, 0,
+ &ad5933_channels[1],
+ 2);
+ if (ret)
+ goto error_unreg_ring;
+
+ /* enable both REAL and IMAG channels by default */
+ iio_scan_mask_set(indio_dev->ring, 0);
+ iio_scan_mask_set(indio_dev->ring, 1);
+
+ ret = ad5933_setup(st);
+ if (ret)
+ goto error_uninitialize_ring;
+
+ return 0;
+
+error_uninitialize_ring:
+ iio_ring_buffer_unregister(indio_dev->ring);
+error_unreg_ring:
+ iio_sw_rb_free(indio_dev->ring);
+error_disable_reg:
+ if (!IS_ERR(st->reg))
+ regulator_disable(st->reg);
+error_put_reg:
+ if (!IS_ERR(st->reg))
+ regulator_put(st->reg);
+
+ if (regdone)
+ iio_device_unregister(indio_dev);
+ else
+ iio_free_device(indio_dev);
+
+ return ret;
+}
+
+static __devexit 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_ring_buffer_unregister(indio_dev->ring);
+ iio_sw_rb_free(indio_dev->ring);
+ if (!IS_ERR(st->reg)) {
+ regulator_disable(st->reg);
+ regulator_put(st->reg);
+ }
+ iio_device_unregister(indio_dev);
+
+ return 0;
+}
+
+static const struct i2c_device_id ad5933_id[] = {
+ { "ad5933", 0 },
+ { "ad5934", 0 },
+ {}
+};
+
+MODULE_DEVICE_TABLE(i2c, ad5933_id);
+
+static struct i2c_driver ad5933_driver = {
+ .driver = {
+ .name = "ad5933",
+ },
+ .probe = ad5933_probe,
+ .remove = __devexit_p(ad5933_remove),
+ .id_table = ad5933_id,
+};
+
+static __init int ad5933_init(void)
+{
+ return i2c_add_driver(&ad5933_driver);
+}
+module_init(ad5933_init);
+
+static __exit void ad5933_exit(void)
+{
+ i2c_del_driver(&ad5933_driver);
+}
+module_exit(ad5933_exit);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@xxxxxxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Analog Devices AD5933 Impedance Conv. Network Analyzer");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/staging/iio/impedance-analyzer/ad5933.h b/drivers/staging/iio/impedance-analyzer/ad5933.h
new file mode 100644
index 0000000..b140e42
--- /dev/null
+++ b/drivers/staging/iio/impedance-analyzer/ad5933.h
@@ -0,0 +1,28 @@
+/*
+ * AD5933 AD5934 Impedance Converter, Network Analyzer
+ *
+ * Copyright 2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+
+#ifndef IIO_ADC_AD5933_H_
+#define IIO_ADC_AD5933_H_
+
+/*
+ * TODO: struct ad5933_platform_data needs to go into include/linux/iio
+ */
+
+/**
+ * struct ad5933_platform_data - platform specific data
+ * @ext_clk_Hz: the external clock frequency in Hz, if not set
+ * the driver uses the internal clock (16.776 MHz)
+ * @vref_mv: the external reference voltage in millivolt
+ */
+
+struct ad5933_platform_data {
+ unsigned long ext_clk_Hz;
+ unsigned short vref_mv;
+};
+
+#endif /* IIO_ADC_AD5933_H_ */
--
1.7.0.4
--
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