diff options
| -rw-r--r-- | drivers/iio/adc/ad_sigma_delta.c | 143 | ||||
| -rw-r--r-- | include/linux/iio/adc/ad_sigma_delta.h | 38 |
2 files changed, 171 insertions, 10 deletions
diff --git a/drivers/iio/adc/ad_sigma_delta.c b/drivers/iio/adc/ad_sigma_delta.c index ebcd52526cac..261a9a6b45e1 100644 --- a/drivers/iio/adc/ad_sigma_delta.c +++ b/drivers/iio/adc/ad_sigma_delta.c @@ -6,6 +6,7 @@ * Author: Lars-Peter Clausen <lars@metafoo.de> */ +#include <linux/align.h> #include <linux/interrupt.h> #include <linux/device.h> #include <linux/kernel.h> @@ -342,15 +343,49 @@ EXPORT_SYMBOL_NS_GPL(ad_sigma_delta_single_conversion, IIO_AD_SIGMA_DELTA); static int ad_sd_buffer_postenable(struct iio_dev *indio_dev) { struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); + unsigned int i, slot, samples_buf_size; unsigned int channel; + uint8_t *samples_buf; int ret; - channel = find_first_bit(indio_dev->active_scan_mask, - indio_dev->masklength); - ret = ad_sigma_delta_set_channel(sigma_delta, - indio_dev->channels[channel].address); - if (ret) - return ret; + if (sigma_delta->num_slots == 1) { + channel = find_first_bit(indio_dev->active_scan_mask, + indio_dev->masklength); + ret = ad_sigma_delta_set_channel(sigma_delta, + indio_dev->channels[channel].address); + if (ret) + return ret; + slot = 1; + } else { + /* + * At this point update_scan_mode already enabled the required channels. + * For sigma-delta sequencer drivers with multiple slots, an update_scan_mode + * implementation is mandatory. + */ + slot = 0; + for_each_set_bit(i, indio_dev->active_scan_mask, indio_dev->masklength) { + sigma_delta->slots[slot] = indio_dev->channels[i].address; + slot++; + } + } + + sigma_delta->active_slots = slot; + sigma_delta->current_slot = 0; + + if (sigma_delta->active_slots > 1) { + ret = ad_sigma_delta_append_status(sigma_delta, true); + if (ret) + return ret; + } + + samples_buf_size = ALIGN(slot * indio_dev->channels[0].scan_type.storagebits, 8); + samples_buf_size += sizeof(int64_t); + samples_buf = devm_krealloc(&sigma_delta->spi->dev, sigma_delta->samples_buf, + samples_buf_size, GFP_KERNEL); + if (!samples_buf) + return -ENOMEM; + + sigma_delta->samples_buf = samples_buf; spi_bus_lock(sigma_delta->spi->master); sigma_delta->bus_locked = true; @@ -386,6 +421,10 @@ static int ad_sd_buffer_postdisable(struct iio_dev *indio_dev) sigma_delta->keep_cs_asserted = false; ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE); + if (sigma_delta->status_appended) + ad_sigma_delta_append_status(sigma_delta, false); + + ad_sigma_delta_disable_all(sigma_delta); sigma_delta->bus_locked = false; return spi_bus_unlock(sigma_delta->spi->master); } @@ -396,6 +435,10 @@ static irqreturn_t ad_sd_trigger_handler(int irq, void *p) struct iio_dev *indio_dev = pf->indio_dev; struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); uint8_t *data = sigma_delta->rx_buf; + unsigned int transfer_size; + unsigned int sample_size; + unsigned int sample_pos; + unsigned int status_pos; unsigned int reg_size; unsigned int data_reg; @@ -408,21 +451,69 @@ static irqreturn_t ad_sd_trigger_handler(int irq, void *p) else data_reg = AD_SD_REG_DATA; + /* Status word will be appended to the sample during transfer */ + if (sigma_delta->status_appended) + transfer_size = reg_size + 1; + else + transfer_size = reg_size; + switch (reg_size) { case 4: case 2: case 1: - ad_sd_read_reg_raw(sigma_delta, data_reg, reg_size, &data[0]); + status_pos = reg_size; + ad_sd_read_reg_raw(sigma_delta, data_reg, transfer_size, &data[0]); break; case 3: + /* + * Data array after transfer will look like (if status is appended): + * data[] = { [0][sample][sample][sample][status] } + * Keeping the first byte 0 shifts the status postion by 1 byte to the right. + */ + status_pos = reg_size + 1; + /* We store 24 bit samples in a 32 bit word. Keep the upper * byte set to zero. */ - ad_sd_read_reg_raw(sigma_delta, data_reg, reg_size, &data[1]); + ad_sd_read_reg_raw(sigma_delta, data_reg, transfer_size, &data[1]); break; } - iio_push_to_buffers_with_timestamp(indio_dev, data, pf->timestamp); + /* + * For devices sampling only one channel at + * once, there is no need for sample number tracking. + */ + if (sigma_delta->active_slots == 1) { + iio_push_to_buffers_with_timestamp(indio_dev, data, pf->timestamp); + goto irq_handled; + } + + if (sigma_delta->status_appended) { + u8 converted_channel; + + converted_channel = data[status_pos] & sigma_delta->info->status_ch_mask; + if (converted_channel != sigma_delta->slots[sigma_delta->current_slot]) { + /* + * Desync occurred during continuous sampling of multiple channels. + * Drop this incomplete sample and start from first channel again. + */ + + sigma_delta->current_slot = 0; + goto irq_handled; + } + } + + sample_size = indio_dev->channels[0].scan_type.storagebits / 8; + sample_pos = sample_size * sigma_delta->current_slot; + memcpy(&sigma_delta->samples_buf[sample_pos], data, sample_size); + sigma_delta->current_slot++; + if (sigma_delta->current_slot == sigma_delta->active_slots) { + sigma_delta->current_slot = 0; + iio_push_to_buffers_with_timestamp(indio_dev, sigma_delta->samples_buf, + pf->timestamp); + } + +irq_handled: iio_trigger_notify_done(indio_dev->trig); sigma_delta->irq_dis = false; enable_irq(sigma_delta->spi->irq); @@ -430,10 +521,17 @@ static irqreturn_t ad_sd_trigger_handler(int irq, void *p) return IRQ_HANDLED; } +static bool ad_sd_validate_scan_mask(struct iio_dev *indio_dev, const unsigned long *mask) +{ + struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); + + return bitmap_weight(mask, indio_dev->masklength) <= sigma_delta->num_slots; +} + static const struct iio_buffer_setup_ops ad_sd_buffer_setup_ops = { .postenable = &ad_sd_buffer_postenable, .postdisable = &ad_sd_buffer_postdisable, - .validate_scan_mask = &iio_validate_scan_mask_onehot, + .validate_scan_mask = &ad_sd_validate_scan_mask, }; static irqreturn_t ad_sd_data_rdy_trig_poll(int irq, void *private) @@ -513,8 +611,14 @@ static int devm_ad_sd_probe_trigger(struct device *dev, struct iio_dev *indio_de */ int devm_ad_sd_setup_buffer_and_trigger(struct device *dev, struct iio_dev *indio_dev) { + struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); int ret; + sigma_delta->slots = devm_kcalloc(dev, sigma_delta->num_slots, + sizeof(*sigma_delta->slots), GFP_KERNEL); + if (!sigma_delta->slots) + return -ENOMEM; + ret = devm_iio_triggered_buffer_setup(dev, indio_dev, &iio_pollfunc_store_time, &ad_sd_trigger_handler, @@ -541,6 +645,25 @@ int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev, { sigma_delta->spi = spi; sigma_delta->info = info; + + /* If the field is unset in ad_sigma_delta_info, asume there can only be 1 slot. */ + if (!info->num_slots) + sigma_delta->num_slots = 1; + else + sigma_delta->num_slots = info->num_slots; + + if (sigma_delta->num_slots > 1) { + if (!indio_dev->info->update_scan_mode) { + dev_err(&spi->dev, "iio_dev lacks update_scan_mode().\n"); + return -EINVAL; + } + + if (!info->disable_all) { + dev_err(&spi->dev, "ad_sigma_delta_info lacks disable_all().\n"); + return -EINVAL; + } + } + iio_device_set_drvdata(indio_dev, sigma_delta); return 0; diff --git a/include/linux/iio/adc/ad_sigma_delta.h b/include/linux/iio/adc/ad_sigma_delta.h index c525fd51652f..7852f6c9a714 100644 --- a/include/linux/iio/adc/ad_sigma_delta.h +++ b/include/linux/iio/adc/ad_sigma_delta.h @@ -32,26 +32,34 @@ struct iio_dev; /** * struct ad_sigma_delta_info - Sigma Delta driver specific callbacks and options * @set_channel: Will be called to select the current channel, may be NULL. + * @append_status: Will be called to enable status append at the end of the sample, may be NULL. * @set_mode: Will be called to select the current mode, may be NULL. + * @disable_all: Will be called to disable all channels, may be NULL. * @postprocess_sample: Is called for each sampled data word, can be used to * modify or drop the sample data, it, may be NULL. * @has_registers: true if the device has writable and readable registers, false * if there is just one read-only sample data shift register. * @addr_shift: Shift of the register address in the communications register. * @read_mask: Mask for the communications register having the read bit set. + * @status_ch_mask: Mask for the channel number stored in status register. * @data_reg: Address of the data register, if 0 the default address of 0x3 will * be used. * @irq_flags: flags for the interrupt used by the triggered buffer + * @num_slots: Number of sequencer slots */ struct ad_sigma_delta_info { int (*set_channel)(struct ad_sigma_delta *, unsigned int channel); + int (*append_status)(struct ad_sigma_delta *, bool append); int (*set_mode)(struct ad_sigma_delta *, enum ad_sigma_delta_mode mode); + int (*disable_all)(struct ad_sigma_delta *); int (*postprocess_sample)(struct ad_sigma_delta *, unsigned int raw_sample); bool has_registers; unsigned int addr_shift; unsigned int read_mask; + unsigned int status_ch_mask; unsigned int data_reg; unsigned long irq_flags; + unsigned int num_slots; }; /** @@ -76,6 +84,13 @@ struct ad_sigma_delta { uint8_t comm; const struct ad_sigma_delta_info *info; + unsigned int active_slots; + unsigned int current_slot; + unsigned int num_slots; + bool status_appended; + /* map slots to channels in order to know what to expect from devices */ + unsigned int *slots; + uint8_t *samples_buf; /* * DMA (thus cache coherency maintenance) requires the @@ -97,6 +112,29 @@ static inline int ad_sigma_delta_set_channel(struct ad_sigma_delta *sd, return 0; } +static inline int ad_sigma_delta_append_status(struct ad_sigma_delta *sd, bool append) +{ + int ret; + + if (sd->info->append_status) { + ret = sd->info->append_status(sd, append); + if (ret < 0) + return ret; + + sd->status_appended = append; + } + + return 0; +} + +static inline int ad_sigma_delta_disable_all(struct ad_sigma_delta *sd) +{ + if (sd->info->disable_all) + return sd->info->disable_all(sd); + + return 0; +} + static inline int ad_sigma_delta_set_mode(struct ad_sigma_delta *sd, unsigned int mode) { |