// SPDX-License-Identifier: GPL-2.0-only /* * Driver for the Diolan DLN-2 USB-ADC adapter * * Copyright (c) 2017 Jack Andersen */ #include #include #include #include #include #include #include #include #include #include #include #include #define DLN2_ADC_MOD_NAME "dln2-adc" #define DLN2_ADC_ID 0x06 #define DLN2_ADC_GET_CHANNEL_COUNT DLN2_CMD(0x01, DLN2_ADC_ID) #define DLN2_ADC_ENABLE DLN2_CMD(0x02, DLN2_ADC_ID) #define DLN2_ADC_DISABLE DLN2_CMD(0x03, DLN2_ADC_ID) #define DLN2_ADC_CHANNEL_ENABLE DLN2_CMD(0x05, DLN2_ADC_ID) #define DLN2_ADC_CHANNEL_DISABLE DLN2_CMD(0x06, DLN2_ADC_ID) #define DLN2_ADC_SET_RESOLUTION DLN2_CMD(0x08, DLN2_ADC_ID) #define DLN2_ADC_CHANNEL_GET_VAL DLN2_CMD(0x0A, DLN2_ADC_ID) #define DLN2_ADC_CHANNEL_GET_ALL_VAL DLN2_CMD(0x0B, DLN2_ADC_ID) #define DLN2_ADC_CHANNEL_SET_CFG DLN2_CMD(0x0C, DLN2_ADC_ID) #define DLN2_ADC_CHANNEL_GET_CFG DLN2_CMD(0x0D, DLN2_ADC_ID) #define DLN2_ADC_CONDITION_MET_EV DLN2_CMD(0x10, DLN2_ADC_ID) #define DLN2_ADC_EVENT_NONE 0 #define DLN2_ADC_EVENT_BELOW 1 #define DLN2_ADC_EVENT_LEVEL_ABOVE 2 #define DLN2_ADC_EVENT_OUTSIDE 3 #define DLN2_ADC_EVENT_INSIDE 4 #define DLN2_ADC_EVENT_ALWAYS 5 #define DLN2_ADC_MAX_CHANNELS 8 #define DLN2_ADC_DATA_BITS 10 /* * Plays similar role to iio_demux_table in subsystem core; except allocated * in a fixed 8-element array. */ struct dln2_adc_demux_table { unsigned int from; unsigned int to; unsigned int length; }; struct dln2_adc { struct platform_device *pdev; struct iio_chan_spec iio_channels[DLN2_ADC_MAX_CHANNELS + 1]; int port, trigger_chan; struct iio_trigger *trig; struct mutex mutex; /* Cached sample period in milliseconds */ unsigned int sample_period; /* Demux table */ unsigned int demux_count; struct dln2_adc_demux_table demux[DLN2_ADC_MAX_CHANNELS]; /* Precomputed timestamp padding offset and length */ unsigned int ts_pad_offset, ts_pad_length; }; struct dln2_adc_port_chan { u8 port; u8 chan; }; struct dln2_adc_get_all_vals { __le16 channel_mask; __le16 values[DLN2_ADC_MAX_CHANNELS]; }; static void dln2_adc_add_demux(struct dln2_adc *dln2, unsigned int in_loc, unsigned int out_loc, unsigned int length) { struct dln2_adc_demux_table *p = dln2->demux_count ? &dln2->demux[dln2->demux_count - 1] : NULL; if (p && p->from + p->length == in_loc && p->to + p->length == out_loc) { p->length += length; } else if (dln2->demux_count < DLN2_ADC_MAX_CHANNELS) { p = &dln2->demux[dln2->demux_count++]; p->from = in_loc; p->to = out_loc; p->length = length; } } static void dln2_adc_update_demux(struct dln2_adc *dln2) { int in_ind = -1, out_ind; unsigned int in_loc = 0, out_loc = 0; struct iio_dev *indio_dev = platform_get_drvdata(dln2->pdev); /* Clear out any old demux */ dln2->demux_count = 0; /* Optimize all 8-channels case */ if (indio_dev->masklength && (*indio_dev->active_scan_mask & 0xff) == 0xff) { dln2_adc_add_demux(dln2, 0, 0, 16); dln2->ts_pad_offset = 0; dln2->ts_pad_length = 0; return; } /* Build demux table from fixed 8-channels to active_scan_mask */ for_each_set_bit(out_ind, indio_dev->active_scan_mask, indio_dev->masklength) { /* Handle timestamp separately */ if (out_ind == DLN2_ADC_MAX_CHANNELS) break; for (++in_ind; in_ind != out_ind; ++in_ind) in_loc += 2; dln2_adc_add_demux(dln2, in_loc, out_loc, 2); out_loc += 2; in_loc += 2; } if (indio_dev->scan_timestamp) { size_t ts_offset = indio_dev->scan_bytes / sizeof(int64_t) - 1; dln2->ts_pad_offset = out_loc; dln2->ts_pad_length = ts_offset * sizeof(int64_t) - out_loc; } else { dln2->ts_pad_offset = 0; dln2->ts_pad_length = 0; } } static int dln2_adc_get_chan_count(struct dln2_adc *dln2) { int ret; u8 port = dln2->port; u8 count; int olen = sizeof(count); ret = dln2_transfer(dln2->pdev, DLN2_ADC_GET_CHANNEL_COUNT, &port, sizeof(port), &count, &olen); if (ret < 0) { dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__); return ret; } if (olen < sizeof(count)) return -EPROTO; return count; } static int dln2_adc_set_port_resolution(struct dln2_adc *dln2) { int ret; struct dln2_adc_port_chan port_chan = { .port = dln2->port, .chan = DLN2_ADC_DATA_BITS, }; ret = dln2_transfer_tx(dln2->pdev, DLN2_ADC_SET_RESOLUTION, &port_chan, sizeof(port_chan)); if (ret < 0) dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__); return ret; } static int dln2_adc_set_chan_enabled(struct dln2_adc *dln2, int channel, bool enable) { int ret; struct dln2_adc_port_chan port_chan = { .port = dln2->port, .chan = channel, }; u16 cmd = enable ? DLN2_ADC_CHANNEL_ENABLE : DLN2_ADC_CHANNEL_DISABLE; ret = dln2_transfer_tx(dln2->pdev, cmd, &port_chan, sizeof(port_chan)); if (ret < 0) dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__); return ret; } static int dln2_adc_set_port_enabled(struct dln2_adc *dln2, bool enable, u16 *conflict_out) { int ret; u8 port = dln2->port; __le16 conflict; int olen = sizeof(conflict); u16 cmd = enable ? DLN2_ADC_ENABLE : DLN2_ADC_DISABLE; if (conflict_out) *conflict_out = 0; ret = dln2_transfer(dln2->pdev, cmd, &port, sizeof(port), &conflict, &olen); if (ret < 0) { dev_dbg(&dln2->pdev->dev, "Problem in %s(%d)\n", __func__, (int)enable); if (conflict_out && enable && olen >= sizeof(conflict)) *conflict_out = le16_to_cpu(conflict); return ret; } if (enable && olen < sizeof(conflict)) return -EPROTO; return ret; } static int dln2_adc_set_chan_period(struct dln2_adc *dln2, unsigned int channel, unsigned int period) { int ret; struct { struct dln2_adc_port_chan port_chan; __u8 type; __le16 period; __le16 low; __le16 high; } __packed set_cfg = { .port_chan.port = dln2->port, .port_chan.chan = channel, .type = period ? DLN2_ADC_EVENT_ALWAYS : DLN2_ADC_EVENT_NONE, .period = cpu_to_le16(period) }; ret = dln2_transfer_tx(dln2->pdev, DLN2_ADC_CHANNEL_SET_CFG, &set_cfg, sizeof(set_cfg)); if (ret < 0) dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__); return ret; } static int dln2_adc_read(struct dln2_adc *dln2, unsigned int channel) { int ret, i; struct iio_dev *indio_dev = platform_get_drvdata(dln2->pdev); u16 conflict; __le16 value; int olen = sizeof(value); struct dln2_adc_port_chan port_chan = { .port = dln2->port, .chan = channel, }; ret = iio_device_claim_direct_mode(indio_dev); if (ret < 0) return ret; ret = dln2_adc_set_chan_enabled(dln2, channel, true); if (ret < 0) goto release_direct; ret = dln2_adc_set_port_enabled(dln2, true, &conflict); if (ret < 0) { if (conflict) { dev_err(&dln2->pdev->dev, "ADC pins conflict with mask %04X\n", (int)conflict); ret = -EBUSY; } goto disable_chan; } /* * Call GET_VAL twice due to initial zero-return immediately after * enabling channel. */ for (i = 0; i < 2; ++i) { ret = dln2_transfer(dln2->pdev, DLN2_ADC_CHANNEL_GET_VAL, &port_chan, sizeof(port_chan), &value, &olen); if (ret < 0) { dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__); goto disable_port; } if (olen < sizeof(value)) { ret = -EPROTO; goto disable_port; } } ret = le16_to_cpu(value); disable_port: dln2_adc_set_port_enabled(dln2, false, NULL); disable_chan: dln2_adc_set_chan_enabled(dln2, channel, false); release_direct: iio_device_release_direct_mode(indio_dev); return ret; } static int dln2_adc_read_all(struct dln2_adc *dln2, struct dln2_adc_get_all_vals *get_all_vals) { int ret; __u8 port = dln2->port; int olen = sizeof(*get_all_vals); ret = dln2_transfer(dln2->pdev, DLN2_ADC_CHANNEL_GET_ALL_VAL, &port, sizeof(port), get_all_vals, &olen); if (ret < 0) { dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__); return ret; } if (olen < sizeof(*get_all_vals)) return -EPROTO; return ret; } static int dln2_adc_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { int ret; unsigned int microhertz; struct dln2_adc *dln2 = iio_priv(indio_dev); switch (mask) { case IIO_CHAN_INFO_RAW: mutex_lock(&dln2->mutex); ret = dln2_adc_read(dln2, chan->channel); mutex_unlock(&dln2->mutex); if (ret < 0) return ret; *val = ret; return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: /* * Voltage reference is fixed at 3.3v * 3.3 / (1 << 10) * 1000000000 */ *val = 0; *val2 = 3222656; return IIO_VAL_INT_PLUS_NANO; case IIO_CHAN_INFO_SAMP_FREQ: if (dln2->sample_period) { microhertz = 1000000000 / dln2->sample_period; *val = microhertz / 1000000; *val2 = microhertz % 1000000; } else { *val = 0; *val2 = 0; } return IIO_VAL_INT_PLUS_MICRO; default: return -EINVAL; } } static int dln2_adc_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { int ret; unsigned int microhertz; struct dln2_adc *dln2 = iio_priv(indio_dev); switch (mask) { case IIO_CHAN_INFO_SAMP_FREQ: microhertz = 1000000 * val + val2; mutex_lock(&dln2->mutex); dln2->sample_period = microhertz ? 1000000000 / microhertz : UINT_MAX; if (dln2->sample_period > 65535) { dln2->sample_period = 65535; dev_warn(&dln2->pdev->dev, "clamping period to 65535ms\n"); } /* * The first requested channel is arbitrated as a shared * trigger source, so only one event is registered with the * DLN. The event handler will then read all enabled channel * values using DLN2_ADC_CHANNEL_GET_ALL_VAL to maintain * synchronization between ADC readings. */ if (dln2->trigger_chan != -1) ret = dln2_adc_set_chan_period(dln2, dln2->trigger_chan, dln2->sample_period); else ret = 0; mutex_unlock(&dln2->mutex); return ret; default: return -EINVAL; } } static int dln2_update_scan_mode(struct iio_dev *indio_dev, const unsigned long *scan_mask) { struct dln2_adc *dln2 = iio_priv(indio_dev); int chan_count = indio_dev->num_channels - 1; int ret, i, j; mutex_lock(&dln2->mutex); for (i = 0; i < chan_count; ++i) { ret = dln2_adc_set_chan_enabled(dln2, i, test_bit(i, scan_mask)); if (ret < 0) { for (j = 0; j < i; ++j) dln2_adc_set_chan_enabled(dln2, j, false); mutex_unlock(&dln2->mutex); dev_err(&dln2->pdev->dev, "Unable to enable ADC channel %d\n", i); return -EBUSY; } } dln2_adc_update_demux(dln2); mutex_unlock(&dln2->mutex); return 0; } #define DLN2_ADC_CHAN(lval, idx) { \ lval.type = IIO_VOLTAGE; \ lval.channel = idx; \ lval.indexed = 1; \ lval.info_mask_separate = BIT(IIO_CHAN_INFO_RAW); \ lval.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE) | \ BIT(IIO_CHAN_INFO_SAMP_FREQ); \ lval.scan_index = idx; \ lval.scan_type.sign = 'u'; \ lval.scan_type.realbits = DLN2_ADC_DATA_BITS; \ lval.scan_type.storagebits = 16; \ lval.scan_type.endianness = IIO_LE; \ } /* Assignment version of IIO_CHAN_SOFT_TIMESTAMP */ #define IIO_CHAN_SOFT_TIMESTAMP_ASSIGN(lval, _si) { \ lval.type = IIO_TIMESTAMP; \ lval.channel = -1; \ lval.scan_index = _si; \ lval.scan_type.sign = 's'; \ lval.scan_type.realbits = 64; \ lval.scan_type.storagebits = 64; \ } static const struct iio_info dln2_adc_info = { .read_raw = dln2_adc_read_raw, .write_raw = dln2_adc_write_raw, .update_scan_mode = dln2_update_scan_mode, }; static irqreturn_t dln2_adc_trigger_h(int irq, void *p) { struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct { __le16 values[DLN2_ADC_MAX_CHANNELS]; int64_t timestamp_space; } data; struct dln2_adc_get_all_vals dev_data; struct dln2_adc *dln2 = iio_priv(indio_dev); const struct dln2_adc_demux_table *t; int ret, i; mutex_lock(&dln2->mutex); ret = dln2_adc_read_all(dln2, &dev_data); mutex_unlock(&dln2->mutex); if (ret < 0) goto done; /* Demux operation */ for (i = 0; i < dln2->demux_count; ++i) { t = &dln2->demux[i]; memcpy((void *)data.values + t->to, (void *)dev_data.values + t->from, t->length); } /* Zero padding space between values and timestamp */ if (dln2->ts_pad_length) memset((void *)data.values + dln2->ts_pad_offset, 0, dln2->ts_pad_length); iio_push_to_buffers_with_timestamp(indio_dev, &data, iio_get_time_ns(indio_dev)); done: iio_trigger_notify_done(indio_dev->trig); return IRQ_HANDLED; } static int dln2_adc_triggered_buffer_postenable(struct iio_dev *indio_dev) { int ret; struct dln2_adc *dln2 = iio_priv(indio_dev); u16 conflict; unsigned int trigger_chan; ret = iio_triggered_buffer_postenable(indio_dev); if (ret) return ret; mutex_lock(&dln2->mutex); /* Enable ADC */ ret = dln2_adc_set_port_enabled(dln2, true, &conflict); if (ret < 0) { mutex_unlock(&dln2->mutex); dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__); if (conflict) { dev_err(&dln2->pdev->dev, "ADC pins conflict with mask %04X\n", (int)conflict); ret = -EBUSY; } iio_triggered_buffer_predisable(indio_dev); return ret; } /* Assign trigger channel based on first enabled channel */ trigger_chan = find_first_bit(indio_dev->active_scan_mask, indio_dev->masklength); if (trigger_chan < DLN2_ADC_MAX_CHANNELS) { dln2->trigger_chan = trigger_chan; ret = dln2_adc_set_chan_period(dln2, dln2->trigger_chan, dln2->sample_period); mutex_unlock(&dln2->mutex); if (ret < 0) { dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__); iio_triggered_buffer_predisable(indio_dev); return ret; } } else { dln2->trigger_chan = -1; mutex_unlock(&dln2->mutex); } return 0; } static int dln2_adc_triggered_buffer_predisable(struct iio_dev *indio_dev) { int ret, ret2; struct dln2_adc *dln2 = iio_priv(indio_dev); mutex_lock(&dln2->mutex); /* Disable trigger channel */ if (dln2->trigger_chan != -1) { dln2_adc_set_chan_period(dln2, dln2->trigger_chan, 0); dln2->trigger_chan = -1; } /* Disable ADC */ ret = dln2_adc_set_port_enabled(dln2, false, NULL); mutex_unlock(&dln2->mutex); if (ret < 0) dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__); ret2 = iio_triggered_buffer_predisable(indio_dev); if (ret == 0) ret = ret2; return ret; } static const struct iio_buffer_setup_ops dln2_adc_buffer_setup_ops = { .postenable = dln2_adc_triggered_buffer_postenable, .predisable = dln2_adc_triggered_buffer_predisable, }; static void dln2_adc_event(struct platform_device *pdev, u16 echo, const void *data, int len) { struct iio_dev *indio_dev = platform_get_drvdata(pdev); struct dln2_adc *dln2 = iio_priv(indio_dev); /* Called via URB completion handler */ iio_trigger_poll(dln2->trig); } static int dln2_adc_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct dln2_adc *dln2; struct dln2_platform_data *pdata = dev_get_platdata(&pdev->dev); struct iio_dev *indio_dev; int i, ret, chans; indio_dev = devm_iio_device_alloc(dev, sizeof(*dln2)); if (!indio_dev) { dev_err(dev, "failed allocating iio device\n"); return -ENOMEM; } dln2 = iio_priv(indio_dev); dln2->pdev = pdev; dln2->port = pdata->port; dln2->trigger_chan = -1; mutex_init(&dln2->mutex); platform_set_drvdata(pdev, indio_dev); ret = dln2_adc_set_port_resolution(dln2); if (ret < 0) { dev_err(dev, "failed to set ADC resolution to 10 bits\n"); return ret; } chans = dln2_adc_get_chan_count(dln2); if (chans < 0) { dev_err(dev, "failed to get channel count: %d\n", chans); return chans; } if (chans > DLN2_ADC_MAX_CHANNELS) { chans = DLN2_ADC_MAX_CHANNELS; dev_warn(dev, "clamping channels to %d\n", DLN2_ADC_MAX_CHANNELS); } for (i = 0; i < chans; ++i) DLN2_ADC_CHAN(dln2->iio_channels[i], i) IIO_CHAN_SOFT_TIMESTAMP_ASSIGN(dln2->iio_channels[i], i); indio_dev->name = DLN2_ADC_MOD_NAME; indio_dev->dev.parent = dev; indio_dev->info = &dln2_adc_info; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = dln2->iio_channels; indio_dev->num_channels = chans + 1; indio_dev->setup_ops = &dln2_adc_buffer_setup_ops; dln2->trig = devm_iio_trigger_alloc(dev, "%s-dev%d", indio_dev->name, indio_dev->id); if (!dln2->trig) { dev_err(dev, "failed to allocate trigger\n"); return -ENOMEM; } iio_trigger_set_drvdata(dln2->trig, dln2); devm_iio_trigger_register(dev, dln2->trig); iio_trigger_set_immutable(indio_dev, dln2->trig); ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL, dln2_adc_trigger_h, &dln2_adc_buffer_setup_ops); if (ret) { dev_err(dev, "failed to allocate triggered buffer: %d\n", ret); return ret; } ret = dln2_register_event_cb(pdev, DLN2_ADC_CONDITION_MET_EV, dln2_adc_event); if (ret) { dev_err(dev, "failed to setup DLN2 periodic event: %d\n", ret); return ret; } ret = iio_device_register(indio_dev); if (ret) { dev_err(dev, "failed to register iio device: %d\n", ret); goto unregister_event; } return ret; unregister_event: dln2_unregister_event_cb(pdev, DLN2_ADC_CONDITION_MET_EV); return ret; } static int dln2_adc_remove(struct platform_device *pdev) { struct iio_dev *indio_dev = platform_get_drvdata(pdev); iio_device_unregister(indio_dev); dln2_unregister_event_cb(pdev, DLN2_ADC_CONDITION_MET_EV); return 0; } static struct platform_driver dln2_adc_driver = { .driver.name = DLN2_ADC_MOD_NAME, .probe = dln2_adc_probe, .remove = dln2_adc_remove, }; module_platform_driver(dln2_adc_driver); MODULE_AUTHOR("Jack Andersen