| /* |
| * Support code for Analog Devices Sigma-Delta ADCs |
| * |
| * Copyright 2012 Analog Devices Inc. |
| * Author: Lars-Peter Clausen <lars@metafoo.de> |
| * |
| * Licensed under the GPL-2. |
| */ |
| |
| #include <linux/interrupt.h> |
| #include <linux/device.h> |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/spi/spi.h> |
| #include <linux/err.h> |
| #include <linux/module.h> |
| |
| #include <linux/iio/iio.h> |
| #include <linux/iio/sysfs.h> |
| #include <linux/iio/buffer.h> |
| #include <linux/iio/trigger.h> |
| #include <linux/iio/trigger_consumer.h> |
| #include <linux/iio/triggered_buffer.h> |
| #include <linux/iio/adc/ad_sigma_delta.h> |
| |
| #include <asm/unaligned.h> |
| |
| |
| #define AD_SD_COMM_CHAN_MASK 0x3 |
| |
| #define AD_SD_REG_COMM 0x00 |
| #define AD_SD_REG_DATA 0x03 |
| |
| /** |
| * ad_sd_set_comm() - Set communications register |
| * |
| * @sigma_delta: The sigma delta device |
| * @comm: New value for the communications register |
| */ |
| void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm) |
| { |
| /* Some variants use the lower two bits of the communications register |
| * to select the channel */ |
| sigma_delta->comm = comm & AD_SD_COMM_CHAN_MASK; |
| } |
| EXPORT_SYMBOL_GPL(ad_sd_set_comm); |
| |
| /** |
| * ad_sd_write_reg() - Write a register |
| * |
| * @sigma_delta: The sigma delta device |
| * @reg: Address of the register |
| * @size: Size of the register (0-3) |
| * @val: Value to write to the register |
| * |
| * Returns 0 on success, an error code otherwise. |
| **/ |
| int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg, |
| unsigned int size, unsigned int val) |
| { |
| uint8_t *data = sigma_delta->data; |
| struct spi_transfer t = { |
| .tx_buf = data, |
| .len = size + 1, |
| .cs_change = sigma_delta->bus_locked, |
| }; |
| struct spi_message m; |
| int ret; |
| |
| data[0] = (reg << sigma_delta->info->addr_shift) | sigma_delta->comm; |
| |
| switch (size) { |
| case 3: |
| data[1] = val >> 16; |
| data[2] = val >> 8; |
| data[3] = val; |
| break; |
| case 2: |
| put_unaligned_be16(val, &data[1]); |
| break; |
| case 1: |
| data[1] = val; |
| break; |
| case 0: |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| spi_message_init(&m); |
| spi_message_add_tail(&t, &m); |
| |
| if (sigma_delta->bus_locked) |
| ret = spi_sync_locked(sigma_delta->spi, &m); |
| else |
| ret = spi_sync(sigma_delta->spi, &m); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(ad_sd_write_reg); |
| |
| static int ad_sd_read_reg_raw(struct ad_sigma_delta *sigma_delta, |
| unsigned int reg, unsigned int size, uint8_t *val) |
| { |
| uint8_t *data = sigma_delta->data; |
| int ret; |
| struct spi_transfer t[] = { |
| { |
| .tx_buf = data, |
| .len = 1, |
| }, { |
| .rx_buf = val, |
| .len = size, |
| .cs_change = sigma_delta->bus_locked, |
| }, |
| }; |
| struct spi_message m; |
| |
| spi_message_init(&m); |
| |
| if (sigma_delta->info->has_registers) { |
| data[0] = reg << sigma_delta->info->addr_shift; |
| data[0] |= sigma_delta->info->read_mask; |
| spi_message_add_tail(&t[0], &m); |
| } |
| spi_message_add_tail(&t[1], &m); |
| |
| if (sigma_delta->bus_locked) |
| ret = spi_sync_locked(sigma_delta->spi, &m); |
| else |
| ret = spi_sync(sigma_delta->spi, &m); |
| |
| return ret; |
| } |
| |
| /** |
| * ad_sd_read_reg() - Read a register |
| * |
| * @sigma_delta: The sigma delta device |
| * @reg: Address of the register |
| * @size: Size of the register (1-4) |
| * @val: Read value |
| * |
| * Returns 0 on success, an error code otherwise. |
| **/ |
| int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, |
| unsigned int reg, unsigned int size, unsigned int *val) |
| { |
| int ret; |
| |
| ret = ad_sd_read_reg_raw(sigma_delta, reg, size, sigma_delta->data); |
| if (ret < 0) |
| goto out; |
| |
| switch (size) { |
| case 4: |
| *val = get_unaligned_be32(sigma_delta->data); |
| break; |
| case 3: |
| *val = (sigma_delta->data[0] << 16) | |
| (sigma_delta->data[1] << 8) | |
| sigma_delta->data[2]; |
| break; |
| case 2: |
| *val = get_unaligned_be16(sigma_delta->data); |
| break; |
| case 1: |
| *val = sigma_delta->data[0]; |
| break; |
| default: |
| ret = -EINVAL; |
| break; |
| } |
| |
| out: |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(ad_sd_read_reg); |
| |
| static int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta, |
| unsigned int mode, unsigned int channel) |
| { |
| int ret; |
| |
| ret = ad_sigma_delta_set_channel(sigma_delta, channel); |
| if (ret) |
| return ret; |
| |
| spi_bus_lock(sigma_delta->spi->master); |
| sigma_delta->bus_locked = true; |
| INIT_COMPLETION(sigma_delta->completion); |
| |
| ret = ad_sigma_delta_set_mode(sigma_delta, mode); |
| if (ret < 0) |
| goto out; |
| |
| sigma_delta->irq_dis = false; |
| enable_irq(sigma_delta->spi->irq); |
| ret = wait_for_completion_timeout(&sigma_delta->completion, 2*HZ); |
| if (ret == 0) { |
| sigma_delta->irq_dis = true; |
| disable_irq_nosync(sigma_delta->spi->irq); |
| ret = -EIO; |
| } else { |
| ret = 0; |
| } |
| out: |
| sigma_delta->bus_locked = false; |
| spi_bus_unlock(sigma_delta->spi->master); |
| ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE); |
| |
| return ret; |
| } |
| |
| /** |
| * ad_sd_calibrate_all() - Performs channel calibration |
| * @sigma_delta: The sigma delta device |
| * @cb: Array of channels and calibration type to perform |
| * @n: Number of items in cb |
| * |
| * Returns 0 on success, an error code otherwise. |
| **/ |
| int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta, |
| const struct ad_sd_calib_data *cb, unsigned int n) |
| { |
| unsigned int i; |
| int ret; |
| |
| for (i = 0; i < n; i++) { |
| ret = ad_sd_calibrate(sigma_delta, cb[i].mode, cb[i].channel); |
| if (ret) |
| return ret; |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(ad_sd_calibrate_all); |
| |
| /** |
| * ad_sigma_delta_single_conversion() - Performs a single data conversion |
| * @indio_dev: The IIO device |
| * @chan: The conversion is done for this channel |
| * @val: Pointer to the location where to store the read value |
| * |
| * Returns: 0 on success, an error value otherwise. |
| */ |
| int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev, |
| const struct iio_chan_spec *chan, int *val) |
| { |
| struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); |
| unsigned int sample, raw_sample; |
| int ret = 0; |
| |
| if (iio_buffer_enabled(indio_dev)) |
| return -EBUSY; |
| |
| mutex_lock(&indio_dev->mlock); |
| ad_sigma_delta_set_channel(sigma_delta, chan->address); |
| |
| spi_bus_lock(sigma_delta->spi->master); |
| sigma_delta->bus_locked = true; |
| INIT_COMPLETION(sigma_delta->completion); |
| |
| ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_SINGLE); |
| |
| sigma_delta->irq_dis = false; |
| enable_irq(sigma_delta->spi->irq); |
| ret = wait_for_completion_interruptible_timeout( |
| &sigma_delta->completion, HZ); |
| |
| sigma_delta->bus_locked = false; |
| spi_bus_unlock(sigma_delta->spi->master); |
| |
| if (ret == 0) |
| ret = -EIO; |
| if (ret < 0) |
| goto out; |
| |
| ret = ad_sd_read_reg(sigma_delta, AD_SD_REG_DATA, |
| DIV_ROUND_UP(chan->scan_type.realbits + chan->scan_type.shift, 8), |
| &raw_sample); |
| |
| out: |
| if (!sigma_delta->irq_dis) { |
| disable_irq_nosync(sigma_delta->spi->irq); |
| sigma_delta->irq_dis = true; |
| } |
| |
| ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE); |
| mutex_unlock(&indio_dev->mlock); |
| |
| if (ret) |
| return ret; |
| |
| sample = raw_sample >> chan->scan_type.shift; |
| sample &= (1 << chan->scan_type.realbits) - 1; |
| *val = sample; |
| |
| ret = ad_sigma_delta_postprocess_sample(sigma_delta, raw_sample); |
| if (ret) |
| return ret; |
| |
| return IIO_VAL_INT; |
| } |
| EXPORT_SYMBOL_GPL(ad_sigma_delta_single_conversion); |
| |
| 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 channel; |
| int ret; |
| |
| ret = iio_triggered_buffer_postenable(indio_dev); |
| if (ret < 0) |
| return 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) |
| goto err_predisable; |
| |
| spi_bus_lock(sigma_delta->spi->master); |
| sigma_delta->bus_locked = true; |
| ret = ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_CONTINUOUS); |
| if (ret) |
| goto err_unlock; |
| |
| sigma_delta->irq_dis = false; |
| enable_irq(sigma_delta->spi->irq); |
| |
| return 0; |
| |
| err_unlock: |
| spi_bus_unlock(sigma_delta->spi->master); |
| err_predisable: |
| |
| return ret; |
| } |
| |
| static int ad_sd_buffer_postdisable(struct iio_dev *indio_dev) |
| { |
| struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); |
| |
| INIT_COMPLETION(sigma_delta->completion); |
| wait_for_completion_timeout(&sigma_delta->completion, HZ); |
| |
| if (!sigma_delta->irq_dis) { |
| disable_irq_nosync(sigma_delta->spi->irq); |
| sigma_delta->irq_dis = true; |
| } |
| |
| ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE); |
| |
| sigma_delta->bus_locked = false; |
| return spi_bus_unlock(sigma_delta->spi->master); |
| } |
| |
| static irqreturn_t ad_sd_trigger_handler(int irq, void *p) |
| { |
| struct iio_poll_func *pf = p; |
| struct iio_dev *indio_dev = pf->indio_dev; |
| struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); |
| unsigned int reg_size; |
| uint8_t data[16]; |
| int ret; |
| |
| memset(data, 0x00, 16); |
| |
| reg_size = indio_dev->channels[0].scan_type.realbits + |
| indio_dev->channels[0].scan_type.shift; |
| reg_size = DIV_ROUND_UP(reg_size, 8); |
| |
| switch (reg_size) { |
| case 4: |
| case 2: |
| case 1: |
| ret = ad_sd_read_reg_raw(sigma_delta, AD_SD_REG_DATA, |
| reg_size, &data[0]); |
| break; |
| case 3: |
| /* We store 24 bit samples in a 32 bit word. Keep the upper |
| * byte set to zero. */ |
| ret = ad_sd_read_reg_raw(sigma_delta, AD_SD_REG_DATA, |
| reg_size, &data[1]); |
| break; |
| } |
| |
| iio_push_to_buffers_with_timestamp(indio_dev, data, pf->timestamp); |
| |
| iio_trigger_notify_done(indio_dev->trig); |
| sigma_delta->irq_dis = false; |
| enable_irq(sigma_delta->spi->irq); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static const struct iio_buffer_setup_ops ad_sd_buffer_setup_ops = { |
| .postenable = &ad_sd_buffer_postenable, |
| .predisable = &iio_triggered_buffer_predisable, |
| .postdisable = &ad_sd_buffer_postdisable, |
| .validate_scan_mask = &iio_validate_scan_mask_onehot, |
| }; |
| |
| static irqreturn_t ad_sd_data_rdy_trig_poll(int irq, void *private) |
| { |
| struct ad_sigma_delta *sigma_delta = private; |
| |
| complete(&sigma_delta->completion); |
| disable_irq_nosync(irq); |
| sigma_delta->irq_dis = true; |
| iio_trigger_poll(sigma_delta->trig, iio_get_time_ns()); |
| |
| return IRQ_HANDLED; |
| } |
| |
| /** |
| * ad_sd_validate_trigger() - validate_trigger callback for ad_sigma_delta devices |
| * @indio_dev: The IIO device |
| * @trig: The new trigger |
| * |
| * Returns: 0 if the 'trig' matches the trigger registered by the ad_sigma_delta |
| * device, -EINVAL otherwise. |
| */ |
| int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig) |
| { |
| struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); |
| |
| if (sigma_delta->trig != trig) |
| return -EINVAL; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(ad_sd_validate_trigger); |
| |
| static const struct iio_trigger_ops ad_sd_trigger_ops = { |
| .owner = THIS_MODULE, |
| }; |
| |
| static int ad_sd_probe_trigger(struct iio_dev *indio_dev) |
| { |
| struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); |
| int ret; |
| |
| sigma_delta->trig = iio_trigger_alloc("%s-dev%d", indio_dev->name, |
| indio_dev->id); |
| if (sigma_delta->trig == NULL) { |
| ret = -ENOMEM; |
| goto error_ret; |
| } |
| sigma_delta->trig->ops = &ad_sd_trigger_ops; |
| init_completion(&sigma_delta->completion); |
| |
| ret = request_irq(sigma_delta->spi->irq, |
| ad_sd_data_rdy_trig_poll, |
| IRQF_TRIGGER_LOW, |
| indio_dev->name, |
| sigma_delta); |
| if (ret) |
| goto error_free_trig; |
| |
| if (!sigma_delta->irq_dis) { |
| sigma_delta->irq_dis = true; |
| disable_irq_nosync(sigma_delta->spi->irq); |
| } |
| sigma_delta->trig->dev.parent = &sigma_delta->spi->dev; |
| iio_trigger_set_drvdata(sigma_delta->trig, sigma_delta); |
| |
| ret = iio_trigger_register(sigma_delta->trig); |
| if (ret) |
| goto error_free_irq; |
| |
| /* select default trigger */ |
| indio_dev->trig = sigma_delta->trig; |
| |
| return 0; |
| |
| error_free_irq: |
| free_irq(sigma_delta->spi->irq, sigma_delta); |
| error_free_trig: |
| iio_trigger_free(sigma_delta->trig); |
| error_ret: |
| return ret; |
| } |
| |
| static void ad_sd_remove_trigger(struct iio_dev *indio_dev) |
| { |
| struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); |
| |
| iio_trigger_unregister(sigma_delta->trig); |
| free_irq(sigma_delta->spi->irq, sigma_delta); |
| iio_trigger_free(sigma_delta->trig); |
| } |
| |
| /** |
| * ad_sd_setup_buffer_and_trigger() - |
| * @indio_dev: The IIO device |
| */ |
| int ad_sd_setup_buffer_and_trigger(struct iio_dev *indio_dev) |
| { |
| int ret; |
| |
| ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time, |
| &ad_sd_trigger_handler, &ad_sd_buffer_setup_ops); |
| if (ret) |
| return ret; |
| |
| ret = ad_sd_probe_trigger(indio_dev); |
| if (ret) { |
| iio_triggered_buffer_cleanup(indio_dev); |
| return ret; |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(ad_sd_setup_buffer_and_trigger); |
| |
| /** |
| * ad_sd_cleanup_buffer_and_trigger() - |
| * @indio_dev: The IIO device |
| */ |
| void ad_sd_cleanup_buffer_and_trigger(struct iio_dev *indio_dev) |
| { |
| ad_sd_remove_trigger(indio_dev); |
| iio_triggered_buffer_cleanup(indio_dev); |
| } |
| EXPORT_SYMBOL_GPL(ad_sd_cleanup_buffer_and_trigger); |
| |
| /** |
| * ad_sd_init() - Initializes a ad_sigma_delta struct |
| * @sigma_delta: The ad_sigma_delta device |
| * @indio_dev: The IIO device which the Sigma Delta device is used for |
| * @spi: The SPI device for the ad_sigma_delta device |
| * @info: Device specific callbacks and options |
| * |
| * This function needs to be called before any other operations are performed on |
| * the ad_sigma_delta struct. |
| */ |
| int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev, |
| struct spi_device *spi, const struct ad_sigma_delta_info *info) |
| { |
| sigma_delta->spi = spi; |
| sigma_delta->info = info; |
| iio_device_set_drvdata(indio_dev, sigma_delta); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(ad_sd_init); |
| |
| MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); |
| MODULE_DESCRIPTION("Analog Devices Sigma-Delta ADCs"); |
| MODULE_LICENSE("GPL v2"); |