/* * 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 #include #include /* 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_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; }; struct ad5933_state { struct i2c_client *client; struct regulator *reg; 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; }; static struct ad5933_platform_data ad5933_default_pdata = { .vref_mv = 3300, }; #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, voltage_uv = 0; struct ad5933_platform_data *pdata = dev_get_platdata(&client->dev); struct ad5933_state *st; struct iio_dev *indio_dev; 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); if (!pdata) pdata = &ad5933_default_pdata; 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; } voltage_uv = regulator_get_voltage(st->reg); if (voltage_uv) st->vref_mv = voltage_uv / 1000; else st->vref_mv = pdata->vref_mv; if (pdata->ext_clk_Hz) { st->mclk_hz = 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_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_reg; 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_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); 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 = ad5933_remove, .id_table = ad5933_id, }; module_i2c_driver(ad5933_driver); MODULE_AUTHOR("Michael Hennerich "); MODULE_DESCRIPTION("Analog Devices AD5933 Impedance Conv. Network Analyzer"); MODULE_LICENSE("GPL v2");