From f94aa354d676532448e8e222e737fdd0755fc786 Mon Sep 17 00:00:00 2001 From: Michael Hennerich Date: Tue, 2 Aug 2011 08:48:22 +0200 Subject: [PATCH] iio: impedance-analyzer: New driver for AD5933/4 Impedance Converter, Network Analyzer 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 Acked-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- .../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(+) 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@vger.kernel.org +Description: + Frequency sweep start frequency in Hz. + +What: /sys/bus/iio/devices/iio:deviceX/outY_freq_increment +KernelVersion: 3.1.0 +Contact: linux-iio@vger.kernel.org +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@vger.kernel.org +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@vger.kernel.org +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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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 "); +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_ */ -- 2.7.4