/* * AD7291 8-Channel, I2C, 12-Bit SAR ADC with Temperature Sensor * * Copyright 2010-2011 Analog Devices Inc. * * Licensed under the GPL-2 or later. */ #include #include #include #include #include #include #include #include #include #include #include "../iio.h" #include "../sysfs.h" #include "../events.h" /* * Simplified handling * * If no events enabled - single polled channel read * If event enabled direct reads disable unless channel * is in the read mask. * * The noise-delayed bit as per datasheet suggestion is always enabled. * */ /* * AD7291 registers definition */ #define AD7291_COMMAND 0x00 #define AD7291_VOLTAGE 0x01 #define AD7291_T_SENSE 0x02 #define AD7291_T_AVERAGE 0x03 #define AD7291_CH0_DATA_HIGH 0x04 #define AD7291_CH0_DATA_LOW 0x05 #define AD7291_CH0_HYST 0x06 #define AD7291_CH1_DATA_HIGH 0x07 #define AD7291_CH1_DATA_LOW 0x08 #define AD7291_CH1_HYST 0x09 #define AD7291_CH2_DATA_HIGH 0x0A #define AD7291_CH2_DATA_LOW 0x0B #define AD7291_CH2_HYST 0x0C #define AD7291_CH3_DATA_HIGH 0x0D #define AD7291_CH3_DATA_LOW 0x0E #define AD7291_CH3_HYST 0x0F #define AD7291_CH4_DATA_HIGH 0x10 #define AD7291_CH4_DATA_LOW 0x11 #define AD7291_CH4_HYST 0x12 #define AD7291_CH5_DATA_HIGH 0x13 #define AD7291_CH5_DATA_LOW 0x14 #define AD7291_CH5_HYST 0x15 #define AD7291_CH6_DATA_HIGH 0x16 #define AD7291_CH6_DATA_LOW 0x17 #define AD7291_CH6_HYST 0x18 #define AD7291_CH7_DATA_HIGH 0x19 #define AD7291_CH7_DATA_LOW 0x1A #define AD7291_CH7_HYST 0x2B #define AD7291_T_SENSE_HIGH 0x1C #define AD7291_T_SENSE_LOW 0x1D #define AD7291_T_SENSE_HYST 0x1E #define AD7291_VOLTAGE_ALERT_STATUS 0x1F #define AD7291_T_ALERT_STATUS 0x20 #define AD7291_VOLTAGE_LIMIT_COUNT 8 /* * AD7291 command */ #define AD7291_AUTOCYCLE (1 << 0) #define AD7291_RESET (1 << 1) #define AD7291_ALERT_CLEAR (1 << 2) #define AD7291_ALERT_POLARITY (1 << 3) #define AD7291_EXT_REF (1 << 4) #define AD7291_NOISE_DELAY (1 << 5) #define AD7291_T_SENSE_MASK (1 << 7) #define AD7291_VOLTAGE_MASK 0xFF00 #define AD7291_VOLTAGE_OFFSET 0x8 /* * AD7291 value masks */ #define AD7291_CHANNEL_MASK 0xF000 #define AD7291_BITS 12 #define AD7291_VALUE_MASK 0xFFF #define AD7291_T_VALUE_SIGN 0x400 #define AD7291_T_VALUE_FLOAT_OFFSET 2 #define AD7291_T_VALUE_FLOAT_MASK 0x2 #define AD7291_BITS 12 struct ad7291_chip_info { struct i2c_client *client; struct regulator *reg; u16 int_vref_mv; u16 command; u16 c_mask; /* Active voltage channels for events */ struct mutex state_lock; }; static int ad7291_i2c_read(struct ad7291_chip_info *chip, u8 reg, u16 *data) { struct i2c_client *client = chip->client; int ret = 0; ret = i2c_smbus_read_word_data(client, reg); if (ret < 0) { dev_err(&client->dev, "I2C read error\n"); return ret; } *data = swab16((u16)ret); return 0; } static int ad7291_i2c_write(struct ad7291_chip_info *chip, u8 reg, u16 data) { return i2c_smbus_write_word_data(chip->client, reg, swab16(data)); } static ssize_t ad7291_store_reset(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { struct iio_dev *indio_dev = dev_get_drvdata(dev); struct ad7291_chip_info *chip = iio_priv(indio_dev); return ad7291_i2c_write(chip, AD7291_COMMAND, chip->command | AD7291_RESET); } static IIO_DEVICE_ATTR(reset, S_IWUSR, NULL, ad7291_store_reset, 0); static struct attribute *ad7291_attributes[] = { &iio_dev_attr_reset.dev_attr.attr, NULL, }; static const struct attribute_group ad7291_attribute_group = { .attrs = ad7291_attributes, }; static irqreturn_t ad7291_event_handler(int irq, void *private) { struct iio_dev *indio_dev = private; struct ad7291_chip_info *chip = iio_priv(private); u16 t_status, v_status; u16 command; int i; s64 timestamp = iio_get_time_ns(); if (ad7291_i2c_read(chip, AD7291_T_ALERT_STATUS, &t_status)) return IRQ_HANDLED; if (ad7291_i2c_read(chip, AD7291_VOLTAGE_ALERT_STATUS, &v_status)) return IRQ_HANDLED; if (!(t_status || v_status)) return IRQ_HANDLED; command = chip->command | AD7291_ALERT_CLEAR; ad7291_i2c_write(chip, AD7291_COMMAND, command); command = chip->command & ~AD7291_ALERT_CLEAR; ad7291_i2c_write(chip, AD7291_COMMAND, command); /* For now treat t_sense and t_sense_average the same */ if ((t_status & (1 << 0)) || (t_status & (1 << 2))) iio_push_event(indio_dev, IIO_UNMOD_EVENT_CODE(IIO_TEMP, 0, IIO_EV_TYPE_THRESH, IIO_EV_DIR_FALLING), timestamp); if ((t_status & (1 << 1)) || (t_status & (1 << 3))) iio_push_event(indio_dev, IIO_UNMOD_EVENT_CODE(IIO_TEMP, 0, IIO_EV_TYPE_THRESH, IIO_EV_DIR_RISING), timestamp); for (i = 0; i < AD7291_VOLTAGE_LIMIT_COUNT*2; i += 2) { if (v_status & (1 << i)) iio_push_event(indio_dev, IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, i/2, IIO_EV_TYPE_THRESH, IIO_EV_DIR_FALLING), timestamp); if (v_status & (1 << (i + 1))) iio_push_event(indio_dev, IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, i/2, IIO_EV_TYPE_THRESH, IIO_EV_DIR_RISING), timestamp); } return IRQ_HANDLED; } static inline ssize_t ad7291_show_hyst(struct device *dev, struct device_attribute *attr, char *buf) { struct iio_dev *indio_dev = dev_get_drvdata(dev); struct ad7291_chip_info *chip = iio_priv(indio_dev); struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); u16 data; int ret; ret = ad7291_i2c_read(chip, this_attr->address, &data); if (ret < 0) return ret; return sprintf(buf, "%d\n", data & AD7291_VALUE_MASK); } static inline ssize_t ad7291_set_hyst(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { struct iio_dev *indio_dev = dev_get_drvdata(dev); struct ad7291_chip_info *chip = iio_priv(indio_dev); struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); u16 data; int ret; ret = kstrtou16(buf, 10, &data); if (ret < 0) return ret; if (data > AD7291_VALUE_MASK) return -EINVAL; ret = ad7291_i2c_write(chip, this_attr->address, data); if (ret < 0) return ret; return len; } static IIO_DEVICE_ATTR(in_temp0_thresh_both_hyst_raw, S_IRUGO | S_IWUSR, ad7291_show_hyst, ad7291_set_hyst, AD7291_T_SENSE_HYST); static IIO_DEVICE_ATTR(in_voltage0_thresh_both_hyst_raw, S_IRUGO | S_IWUSR, ad7291_show_hyst, ad7291_set_hyst, AD7291_CH0_HYST); static IIO_DEVICE_ATTR(in_voltage1_thresh_both_hyst_raw, S_IRUGO | S_IWUSR, ad7291_show_hyst, ad7291_set_hyst, AD7291_CH1_HYST); static IIO_DEVICE_ATTR(in_voltage2_thresh_both_hyst_raw, S_IRUGO | S_IWUSR, ad7291_show_hyst, ad7291_set_hyst, AD7291_CH2_HYST); static IIO_DEVICE_ATTR(in_voltage3_thresh_both_hyst_raw, S_IRUGO | S_IWUSR, ad7291_show_hyst, ad7291_set_hyst, AD7291_CH3_HYST); static IIO_DEVICE_ATTR(in_voltage4_thresh_both_hyst_raw, S_IRUGO | S_IWUSR, ad7291_show_hyst, ad7291_set_hyst, AD7291_CH4_HYST); static IIO_DEVICE_ATTR(in_voltage5_thresh_both_hyst_raw, S_IRUGO | S_IWUSR, ad7291_show_hyst, ad7291_set_hyst, AD7291_CH5_HYST); static IIO_DEVICE_ATTR(in_voltage6_thresh_both_hyst_raw, S_IRUGO | S_IWUSR, ad7291_show_hyst, ad7291_set_hyst, AD7291_CH6_HYST); static IIO_DEVICE_ATTR(in_voltage7_thresh_both_hyst_raw, S_IRUGO | S_IWUSR, ad7291_show_hyst, ad7291_set_hyst, AD7291_CH7_HYST); static struct attribute *ad7291_event_attributes[] = { &iio_dev_attr_in_temp0_thresh_both_hyst_raw.dev_attr.attr, &iio_dev_attr_in_voltage0_thresh_both_hyst_raw.dev_attr.attr, &iio_dev_attr_in_voltage1_thresh_both_hyst_raw.dev_attr.attr, &iio_dev_attr_in_voltage2_thresh_both_hyst_raw.dev_attr.attr, &iio_dev_attr_in_voltage3_thresh_both_hyst_raw.dev_attr.attr, &iio_dev_attr_in_voltage4_thresh_both_hyst_raw.dev_attr.attr, &iio_dev_attr_in_voltage5_thresh_both_hyst_raw.dev_attr.attr, &iio_dev_attr_in_voltage6_thresh_both_hyst_raw.dev_attr.attr, &iio_dev_attr_in_voltage7_thresh_both_hyst_raw.dev_attr.attr, NULL, }; /* high / low */ static u8 ad7291_limit_regs[9][2] = { { AD7291_CH0_DATA_HIGH, AD7291_CH0_DATA_LOW }, { AD7291_CH1_DATA_HIGH, AD7291_CH1_DATA_LOW }, { AD7291_CH2_DATA_HIGH, AD7291_CH2_DATA_LOW }, { AD7291_CH3_DATA_HIGH, AD7291_CH3_DATA_LOW }, /* FIXME: ? */ { AD7291_CH4_DATA_HIGH, AD7291_CH4_DATA_LOW }, { AD7291_CH5_DATA_HIGH, AD7291_CH5_DATA_LOW }, { AD7291_CH6_DATA_HIGH, AD7291_CH6_DATA_LOW }, { AD7291_CH7_DATA_HIGH, AD7291_CH7_DATA_LOW }, /* temp */ { AD7291_T_SENSE_HIGH, AD7291_T_SENSE_LOW }, }; static int ad7291_read_event_value(struct iio_dev *indio_dev, u64 event_code, int *val) { struct ad7291_chip_info *chip = iio_priv(indio_dev); int ret; u8 reg; u16 uval; s16 signval; switch (IIO_EVENT_CODE_EXTRACT_CHAN_TYPE(event_code)) { case IIO_VOLTAGE: reg = ad7291_limit_regs[IIO_EVENT_CODE_EXTRACT_NUM(event_code)] [!(IIO_EVENT_CODE_EXTRACT_DIR(event_code) == IIO_EV_DIR_RISING)]; ret = ad7291_i2c_read(chip, reg, &uval); if (ret < 0) return ret; *val = uval & AD7291_VALUE_MASK; return 0; case IIO_TEMP: reg = ad7291_limit_regs[8] [!(IIO_EVENT_CODE_EXTRACT_DIR(event_code) == IIO_EV_DIR_RISING)]; ret = ad7291_i2c_read(chip, reg, &signval); if (ret < 0) return ret; signval = (s16)((signval & AD7291_VALUE_MASK) << 4) >> 4; *val = signval; return 0; default: return -EINVAL; }; } static int ad7291_write_event_value(struct iio_dev *indio_dev, u64 event_code, int val) { struct ad7291_chip_info *chip = iio_priv(indio_dev); u8 reg; s16 signval; switch (IIO_EVENT_CODE_EXTRACT_CHAN_TYPE(event_code)) { case IIO_VOLTAGE: if (val > AD7291_VALUE_MASK || val < 0) return -EINVAL; reg = ad7291_limit_regs[IIO_EVENT_CODE_EXTRACT_NUM(event_code)] [!(IIO_EVENT_CODE_EXTRACT_DIR(event_code) == IIO_EV_DIR_RISING)]; return ad7291_i2c_write(chip, reg, val); case IIO_TEMP: if (val > 2047 || val < -2048) return -EINVAL; reg = ad7291_limit_regs[8] [!(IIO_EVENT_CODE_EXTRACT_DIR(event_code) == IIO_EV_DIR_RISING)]; signval = val; return ad7291_i2c_write(chip, reg, *(u16 *)&signval); default: return -EINVAL; }; } static int ad7291_read_event_config(struct iio_dev *indio_dev, u64 event_code) { struct ad7291_chip_info *chip = iio_priv(indio_dev); /* To be enabled the channel must simply be on. If any are enabled we are in continuous sampling mode */ switch (IIO_EVENT_CODE_EXTRACT_CHAN_TYPE(event_code)) { case IIO_VOLTAGE: if (chip->c_mask & (1 << (15 - IIO_EVENT_CODE_EXTRACT_NUM(event_code)))) return 1; else return 0; case IIO_TEMP: /* always on */ return 1; default: return -EINVAL; } } static int ad7291_write_event_config(struct iio_dev *indio_dev, u64 event_code, int state) { int ret = 0; struct ad7291_chip_info *chip = iio_priv(indio_dev); u16 regval; mutex_lock(&chip->state_lock); regval = chip->command; /* * To be enabled the channel must simply be on. If any are enabled * use continuous sampling mode. * Possible to disable temp as well but that makes single read tricky. */ switch (IIO_EVENT_CODE_EXTRACT_TYPE(event_code)) { case IIO_VOLTAGE: if ((!state) && (chip->c_mask & (1 << (15 - IIO_EVENT_CODE_EXTRACT_NUM(event_code))))) chip->c_mask &= ~(1 << (15 - IIO_EVENT_CODE_EXTRACT_NUM (event_code))); else if (state && (!(chip->c_mask & (1 << (15 - IIO_EVENT_CODE_EXTRACT_NUM(event_code)))))) chip->c_mask |= (1 << (15 - IIO_EVENT_CODE_EXTRACT_NUM (event_code))); else break; regval &= ~AD7291_AUTOCYCLE; regval |= chip->c_mask; if (chip->c_mask) /* Enable autocycle? */ regval |= AD7291_AUTOCYCLE; ret = ad7291_i2c_write(chip, AD7291_COMMAND, regval); if (ret < 0) goto error_ret; chip->command = regval; break; default: ret = -EINVAL; } error_ret: mutex_unlock(&chip->state_lock); return ret; } static int ad7291_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { int ret; struct ad7291_chip_info *chip = iio_priv(indio_dev); unsigned int scale_uv; u16 regval; s16 signval; switch (mask) { case 0: switch (chan->type) { case IIO_VOLTAGE: mutex_lock(&chip->state_lock); /* If in autocycle mode drop through */ if (chip->command & AD7291_AUTOCYCLE) { mutex_unlock(&chip->state_lock); return -EBUSY; } /* Enable this channel alone */ regval = chip->command & (~AD7291_VOLTAGE_MASK); regval |= 1 << (15 - chan->channel); ret = ad7291_i2c_write(chip, AD7291_COMMAND, regval); if (ret < 0) { mutex_unlock(&chip->state_lock); return ret; } /* Read voltage */ ret = i2c_smbus_read_word_data(chip->client, AD7291_VOLTAGE); if (ret < 0) { mutex_unlock(&chip->state_lock); return ret; } *val = swab16((u16)ret) & AD7291_VALUE_MASK; mutex_unlock(&chip->state_lock); return IIO_VAL_INT; case IIO_TEMP: /* Assumes tsense bit of command register always set */ ret = i2c_smbus_read_word_data(chip->client, AD7291_T_SENSE); if (ret < 0) return ret; signval = (s16)((swab16((u16)ret) & AD7291_VALUE_MASK) << 4) >> 4; *val = signval; return IIO_VAL_INT; default: return -EINVAL; } case IIO_CHAN_INFO_AVERAGE_RAW: ret = i2c_smbus_read_word_data(chip->client, AD7291_T_AVERAGE); if (ret < 0) return ret; signval = (s16)((swab16((u16)ret) & AD7291_VALUE_MASK) << 4) >> 4; *val = signval; return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: switch (chan->type) { case IIO_VOLTAGE: scale_uv = (chip->int_vref_mv * 1000) >> AD7291_BITS; *val = scale_uv / 1000; *val2 = (scale_uv % 1000) * 1000; return IIO_VAL_INT_PLUS_MICRO; case IIO_TEMP: /* * One LSB of the ADC corresponds to 0.25 deg C. * The temperature reading is in 12-bit twos * complement format */ *val = 250; return IIO_VAL_INT; default: return -EINVAL; } default: return -EINVAL; } } #define AD7291_VOLTAGE_CHAN(_chan) \ { \ .type = IIO_VOLTAGE, \ .info_mask = IIO_CHAN_INFO_SCALE_SHARED_BIT, \ .indexed = 1, \ .channel = _chan, \ .event_mask = IIO_EV_BIT(IIO_EV_TYPE_THRESH, IIO_EV_DIR_RISING)|\ IIO_EV_BIT(IIO_EV_TYPE_THRESH, IIO_EV_DIR_FALLING) \ } static const struct iio_chan_spec ad7291_channels[] = { AD7291_VOLTAGE_CHAN(0), AD7291_VOLTAGE_CHAN(1), AD7291_VOLTAGE_CHAN(2), AD7291_VOLTAGE_CHAN(3), AD7291_VOLTAGE_CHAN(4), AD7291_VOLTAGE_CHAN(5), AD7291_VOLTAGE_CHAN(6), AD7291_VOLTAGE_CHAN(7), { .type = IIO_TEMP, .info_mask = IIO_CHAN_INFO_AVERAGE_RAW_SEPARATE_BIT | IIO_CHAN_INFO_SCALE_SEPARATE_BIT, .indexed = 1, .channel = 0, .event_mask = IIO_EV_BIT(IIO_EV_TYPE_THRESH, IIO_EV_DIR_RISING)| IIO_EV_BIT(IIO_EV_TYPE_THRESH, IIO_EV_DIR_FALLING) } }; static struct attribute_group ad7291_event_attribute_group = { .attrs = ad7291_event_attributes, }; static const struct iio_info ad7291_info = { .attrs = &ad7291_attribute_group, .read_raw = &ad7291_read_raw, .read_event_config = &ad7291_read_event_config, .write_event_config = &ad7291_write_event_config, .read_event_value = &ad7291_read_event_value, .write_event_value = &ad7291_write_event_value, .event_attrs = &ad7291_event_attribute_group, }; static int __devinit ad7291_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct ad7291_chip_info *chip; struct iio_dev *indio_dev; int ret = 0, voltage_uv = 0; indio_dev = iio_allocate_device(sizeof(*chip)); if (indio_dev == NULL) { ret = -ENOMEM; goto error_ret; } chip = iio_priv(indio_dev); chip->reg = regulator_get(&client->dev, "vcc"); if (!IS_ERR(chip->reg)) { ret = regulator_enable(chip->reg); if (ret) goto error_put_reg; voltage_uv = regulator_get_voltage(chip->reg); } mutex_init(&chip->state_lock); /* this is only used for device removal purposes */ i2c_set_clientdata(client, indio_dev); chip->client = client; chip->command = AD7291_NOISE_DELAY | AD7291_T_SENSE_MASK | /* Tsense always enabled */ AD7291_ALERT_POLARITY; /* set irq polarity low level */ if (voltage_uv) { chip->int_vref_mv = voltage_uv / 1000; chip->command |= AD7291_EXT_REF; } else { chip->int_vref_mv = 2500; /* Build-in ref */ } indio_dev->name = id->name; indio_dev->channels = ad7291_channels; indio_dev->num_channels = ARRAY_SIZE(ad7291_channels); indio_dev->dev.parent = &client->dev; indio_dev->info = &ad7291_info; indio_dev->modes = INDIO_DIRECT_MODE; ret = ad7291_i2c_write(chip, AD7291_COMMAND, AD7291_RESET); if (ret) { ret = -EIO; goto error_disable_reg; } ret = ad7291_i2c_write(chip, AD7291_COMMAND, chip->command); if (ret) { ret = -EIO; goto error_disable_reg; } if (client->irq > 0) { ret = request_threaded_irq(client->irq, NULL, &ad7291_event_handler, IRQF_TRIGGER_LOW | IRQF_ONESHOT, id->name, indio_dev); if (ret) goto error_disable_reg; } ret = iio_device_register(indio_dev); if (ret) goto error_unreg_irq; dev_info(&client->dev, "%s ADC registered.\n", id->name); return 0; error_unreg_irq: if (client->irq) free_irq(client->irq, indio_dev); error_disable_reg: if (!IS_ERR(chip->reg)) regulator_disable(chip->reg); error_put_reg: if (!IS_ERR(chip->reg)) regulator_put(chip->reg); iio_free_device(indio_dev); error_ret: return ret; } static int __devexit ad7291_remove(struct i2c_client *client) { struct iio_dev *indio_dev = i2c_get_clientdata(client); struct ad7291_chip_info *chip = iio_priv(indio_dev); iio_device_unregister(indio_dev); if (client->irq) free_irq(client->irq, indio_dev); if (!IS_ERR(chip->reg)) { regulator_disable(chip->reg); regulator_put(chip->reg); } iio_free_device(indio_dev); return 0; } static const struct i2c_device_id ad7291_id[] = { { "ad7291", 0 }, {} }; MODULE_DEVICE_TABLE(i2c, ad7291_id); static struct i2c_driver ad7291_driver = { .driver = { .name = KBUILD_MODNAME, }, .probe = ad7291_probe, .remove = __devexit_p(ad7291_remove), .id_table = ad7291_id, }; module_i2c_driver(ad7291_driver); MODULE_AUTHOR("Sonic Zhang "); MODULE_DESCRIPTION("Analog Devices AD7291 ADC driver"); MODULE_LICENSE("GPL v2");