| /* |
| * AD7266/65 SPI ADC driver |
| * |
| * Copyright 2012 Analog Devices Inc. |
| * |
| * Licensed under the GPL-2. |
| */ |
| |
| #include <linux/device.h> |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/spi/spi.h> |
| #include <linux/regulator/consumer.h> |
| #include <linux/err.h> |
| #include <linux/gpio.h> |
| #include <linux/module.h> |
| |
| #include <linux/interrupt.h> |
| |
| #include <linux/iio/iio.h> |
| #include <linux/iio/buffer.h> |
| #include <linux/iio/trigger_consumer.h> |
| #include <linux/iio/triggered_buffer.h> |
| |
| #include <linux/platform_data/ad7266.h> |
| |
| struct ad7266_state { |
| struct spi_device *spi; |
| struct regulator *reg; |
| unsigned long vref_uv; |
| |
| struct spi_transfer single_xfer[3]; |
| struct spi_message single_msg; |
| |
| enum ad7266_range range; |
| enum ad7266_mode mode; |
| bool fixed_addr; |
| struct gpio gpios[3]; |
| |
| /* |
| * DMA (thus cache coherency maintenance) requires the |
| * transfer buffers to live in their own cache lines. |
| * The buffer needs to be large enough to hold two samples (4 bytes) and |
| * the naturally aligned timestamp (8 bytes). |
| */ |
| uint8_t data[ALIGN(4, sizeof(s64)) + sizeof(s64)] ____cacheline_aligned; |
| }; |
| |
| static int ad7266_wakeup(struct ad7266_state *st) |
| { |
| /* Any read with >= 2 bytes will wake the device */ |
| return spi_read(st->spi, st->data, 2); |
| } |
| |
| static int ad7266_powerdown(struct ad7266_state *st) |
| { |
| /* Any read with < 2 bytes will powerdown the device */ |
| return spi_read(st->spi, st->data, 1); |
| } |
| |
| static int ad7266_preenable(struct iio_dev *indio_dev) |
| { |
| struct ad7266_state *st = iio_priv(indio_dev); |
| int ret; |
| |
| ret = ad7266_wakeup(st); |
| if (ret) |
| return ret; |
| |
| ret = iio_sw_buffer_preenable(indio_dev); |
| if (ret) |
| ad7266_powerdown(st); |
| |
| return ret; |
| } |
| |
| static int ad7266_postdisable(struct iio_dev *indio_dev) |
| { |
| struct ad7266_state *st = iio_priv(indio_dev); |
| return ad7266_powerdown(st); |
| } |
| |
| static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = { |
| .preenable = &ad7266_preenable, |
| .postenable = &iio_triggered_buffer_postenable, |
| .predisable = &iio_triggered_buffer_predisable, |
| .postdisable = &ad7266_postdisable, |
| }; |
| |
| static irqreturn_t ad7266_trigger_handler(int irq, void *p) |
| { |
| struct iio_poll_func *pf = p; |
| struct iio_dev *indio_dev = pf->indio_dev; |
| struct ad7266_state *st = iio_priv(indio_dev); |
| int ret; |
| |
| ret = spi_read(st->spi, st->data, 4); |
| if (ret == 0) { |
| if (indio_dev->scan_timestamp) |
| ((s64 *)st->data)[1] = pf->timestamp; |
| iio_push_to_buffers(indio_dev, (u8 *)st->data); |
| } |
| |
| iio_trigger_notify_done(indio_dev->trig); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static void ad7266_select_input(struct ad7266_state *st, unsigned int nr) |
| { |
| unsigned int i; |
| |
| if (st->fixed_addr) |
| return; |
| |
| switch (st->mode) { |
| case AD7266_MODE_SINGLE_ENDED: |
| nr >>= 1; |
| break; |
| case AD7266_MODE_PSEUDO_DIFF: |
| nr |= 1; |
| break; |
| case AD7266_MODE_DIFF: |
| nr &= ~1; |
| break; |
| } |
| |
| for (i = 0; i < 3; ++i) |
| gpio_set_value(st->gpios[i].gpio, (bool)(nr & BIT(i))); |
| } |
| |
| static int ad7266_update_scan_mode(struct iio_dev *indio_dev, |
| const unsigned long *scan_mask) |
| { |
| struct ad7266_state *st = iio_priv(indio_dev); |
| unsigned int nr = find_first_bit(scan_mask, indio_dev->masklength); |
| |
| ad7266_select_input(st, nr); |
| |
| return 0; |
| } |
| |
| static int ad7266_read_single(struct ad7266_state *st, int *val, |
| unsigned int address) |
| { |
| int ret; |
| |
| ad7266_select_input(st, address); |
| |
| ret = spi_sync(st->spi, &st->single_msg); |
| *val = be16_to_cpu(st->data[address % 2]); |
| |
| return ret; |
| } |
| |
| static int ad7266_read_raw(struct iio_dev *indio_dev, |
| struct iio_chan_spec const *chan, int *val, int *val2, long m) |
| { |
| struct ad7266_state *st = iio_priv(indio_dev); |
| unsigned long scale_uv; |
| int ret; |
| |
| switch (m) { |
| case IIO_CHAN_INFO_RAW: |
| if (iio_buffer_enabled(indio_dev)) |
| return -EBUSY; |
| |
| ret = ad7266_read_single(st, val, chan->address); |
| if (ret) |
| return ret; |
| |
| *val = (*val >> 2) & 0xfff; |
| if (chan->scan_type.sign == 's') |
| *val = sign_extend32(*val, 11); |
| |
| return IIO_VAL_INT; |
| case IIO_CHAN_INFO_SCALE: |
| scale_uv = (st->vref_uv * 100); |
| if (st->mode == AD7266_MODE_DIFF) |
| scale_uv *= 2; |
| if (st->range == AD7266_RANGE_2VREF) |
| scale_uv *= 2; |
| |
| scale_uv >>= chan->scan_type.realbits; |
| *val = scale_uv / 100000; |
| *val2 = (scale_uv % 100000) * 10; |
| return IIO_VAL_INT_PLUS_MICRO; |
| case IIO_CHAN_INFO_OFFSET: |
| if (st->range == AD7266_RANGE_2VREF && |
| st->mode != AD7266_MODE_DIFF) |
| *val = 2048; |
| else |
| *val = 0; |
| return IIO_VAL_INT; |
| } |
| return -EINVAL; |
| } |
| |
| #define AD7266_CHAN(_chan, _sign) { \ |
| .type = IIO_VOLTAGE, \ |
| .indexed = 1, \ |
| .channel = (_chan), \ |
| .address = (_chan), \ |
| .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT \ |
| | IIO_CHAN_INFO_SCALE_SHARED_BIT \ |
| | IIO_CHAN_INFO_OFFSET_SHARED_BIT, \ |
| .scan_index = (_chan), \ |
| .scan_type = { \ |
| .sign = (_sign), \ |
| .realbits = 12, \ |
| .storagebits = 16, \ |
| .shift = 2, \ |
| .endianness = IIO_BE, \ |
| }, \ |
| } |
| |
| #define AD7266_DECLARE_SINGLE_ENDED_CHANNELS(_name, _sign) \ |
| const struct iio_chan_spec ad7266_channels_##_name[] = { \ |
| AD7266_CHAN(0, (_sign)), \ |
| AD7266_CHAN(1, (_sign)), \ |
| AD7266_CHAN(2, (_sign)), \ |
| AD7266_CHAN(3, (_sign)), \ |
| AD7266_CHAN(4, (_sign)), \ |
| AD7266_CHAN(5, (_sign)), \ |
| AD7266_CHAN(6, (_sign)), \ |
| AD7266_CHAN(7, (_sign)), \ |
| AD7266_CHAN(8, (_sign)), \ |
| AD7266_CHAN(9, (_sign)), \ |
| AD7266_CHAN(10, (_sign)), \ |
| AD7266_CHAN(11, (_sign)), \ |
| IIO_CHAN_SOFT_TIMESTAMP(13), \ |
| } |
| |
| #define AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(_name, _sign) \ |
| const struct iio_chan_spec ad7266_channels_##_name##_fixed[] = { \ |
| AD7266_CHAN(0, (_sign)), \ |
| AD7266_CHAN(1, (_sign)), \ |
| IIO_CHAN_SOFT_TIMESTAMP(2), \ |
| } |
| |
| static AD7266_DECLARE_SINGLE_ENDED_CHANNELS(u, 'u'); |
| static AD7266_DECLARE_SINGLE_ENDED_CHANNELS(s, 's'); |
| static AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(u, 'u'); |
| static AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(s, 's'); |
| |
| #define AD7266_CHAN_DIFF(_chan, _sign) { \ |
| .type = IIO_VOLTAGE, \ |
| .indexed = 1, \ |
| .channel = (_chan) * 2, \ |
| .channel2 = (_chan) * 2 + 1, \ |
| .address = (_chan), \ |
| .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT \ |
| | IIO_CHAN_INFO_SCALE_SHARED_BIT \ |
| | IIO_CHAN_INFO_OFFSET_SHARED_BIT, \ |
| .scan_index = (_chan), \ |
| .scan_type = { \ |
| .sign = _sign, \ |
| .realbits = 12, \ |
| .storagebits = 16, \ |
| .shift = 2, \ |
| .endianness = IIO_BE, \ |
| }, \ |
| .differential = 1, \ |
| } |
| |
| #define AD7266_DECLARE_DIFF_CHANNELS(_name, _sign) \ |
| const struct iio_chan_spec ad7266_channels_diff_##_name[] = { \ |
| AD7266_CHAN_DIFF(0, (_sign)), \ |
| AD7266_CHAN_DIFF(1, (_sign)), \ |
| AD7266_CHAN_DIFF(2, (_sign)), \ |
| AD7266_CHAN_DIFF(3, (_sign)), \ |
| AD7266_CHAN_DIFF(4, (_sign)), \ |
| AD7266_CHAN_DIFF(5, (_sign)), \ |
| IIO_CHAN_SOFT_TIMESTAMP(6), \ |
| } |
| |
| static AD7266_DECLARE_DIFF_CHANNELS(s, 's'); |
| static AD7266_DECLARE_DIFF_CHANNELS(u, 'u'); |
| |
| #define AD7266_DECLARE_DIFF_CHANNELS_FIXED(_name, _sign) \ |
| const struct iio_chan_spec ad7266_channels_diff_fixed_##_name[] = { \ |
| AD7266_CHAN_DIFF(0, (_sign)), \ |
| AD7266_CHAN_DIFF(1, (_sign)), \ |
| IIO_CHAN_SOFT_TIMESTAMP(2), \ |
| } |
| |
| static AD7266_DECLARE_DIFF_CHANNELS_FIXED(s, 's'); |
| static AD7266_DECLARE_DIFF_CHANNELS_FIXED(u, 'u'); |
| |
| static const struct iio_info ad7266_info = { |
| .read_raw = &ad7266_read_raw, |
| .update_scan_mode = &ad7266_update_scan_mode, |
| .driver_module = THIS_MODULE, |
| }; |
| |
| static unsigned long ad7266_available_scan_masks[] = { |
| 0x003, |
| 0x00c, |
| 0x030, |
| 0x0c0, |
| 0x300, |
| 0xc00, |
| 0x000, |
| }; |
| |
| static unsigned long ad7266_available_scan_masks_diff[] = { |
| 0x003, |
| 0x00c, |
| 0x030, |
| 0x000, |
| }; |
| |
| static unsigned long ad7266_available_scan_masks_fixed[] = { |
| 0x003, |
| 0x000, |
| }; |
| |
| struct ad7266_chan_info { |
| const struct iio_chan_spec *channels; |
| unsigned int num_channels; |
| unsigned long *scan_masks; |
| }; |
| |
| #define AD7266_CHAN_INFO_INDEX(_differential, _signed, _fixed) \ |
| (((_differential) << 2) | ((_signed) << 1) | ((_fixed) << 0)) |
| |
| static const struct ad7266_chan_info ad7266_chan_infos[] = { |
| [AD7266_CHAN_INFO_INDEX(0, 0, 0)] = { |
| .channels = ad7266_channels_u, |
| .num_channels = ARRAY_SIZE(ad7266_channels_u), |
| .scan_masks = ad7266_available_scan_masks, |
| }, |
| [AD7266_CHAN_INFO_INDEX(0, 0, 1)] = { |
| .channels = ad7266_channels_u_fixed, |
| .num_channels = ARRAY_SIZE(ad7266_channels_u_fixed), |
| .scan_masks = ad7266_available_scan_masks_fixed, |
| }, |
| [AD7266_CHAN_INFO_INDEX(0, 1, 0)] = { |
| .channels = ad7266_channels_s, |
| .num_channels = ARRAY_SIZE(ad7266_channels_s), |
| .scan_masks = ad7266_available_scan_masks, |
| }, |
| [AD7266_CHAN_INFO_INDEX(0, 1, 1)] = { |
| .channels = ad7266_channels_s_fixed, |
| .num_channels = ARRAY_SIZE(ad7266_channels_s_fixed), |
| .scan_masks = ad7266_available_scan_masks_fixed, |
| }, |
| [AD7266_CHAN_INFO_INDEX(1, 0, 0)] = { |
| .channels = ad7266_channels_diff_u, |
| .num_channels = ARRAY_SIZE(ad7266_channels_diff_u), |
| .scan_masks = ad7266_available_scan_masks_diff, |
| }, |
| [AD7266_CHAN_INFO_INDEX(1, 0, 1)] = { |
| .channels = ad7266_channels_diff_fixed_u, |
| .num_channels = ARRAY_SIZE(ad7266_channels_diff_fixed_u), |
| .scan_masks = ad7266_available_scan_masks_fixed, |
| }, |
| [AD7266_CHAN_INFO_INDEX(1, 1, 0)] = { |
| .channels = ad7266_channels_diff_s, |
| .num_channels = ARRAY_SIZE(ad7266_channels_diff_s), |
| .scan_masks = ad7266_available_scan_masks_diff, |
| }, |
| [AD7266_CHAN_INFO_INDEX(1, 1, 1)] = { |
| .channels = ad7266_channels_diff_fixed_s, |
| .num_channels = ARRAY_SIZE(ad7266_channels_diff_fixed_s), |
| .scan_masks = ad7266_available_scan_masks_fixed, |
| }, |
| }; |
| |
| static void ad7266_init_channels(struct iio_dev *indio_dev) |
| { |
| struct ad7266_state *st = iio_priv(indio_dev); |
| bool is_differential, is_signed; |
| const struct ad7266_chan_info *chan_info; |
| int i; |
| |
| is_differential = st->mode != AD7266_MODE_SINGLE_ENDED; |
| is_signed = (st->range == AD7266_RANGE_2VREF) | |
| (st->mode == AD7266_MODE_DIFF); |
| |
| i = AD7266_CHAN_INFO_INDEX(is_differential, is_signed, st->fixed_addr); |
| chan_info = &ad7266_chan_infos[i]; |
| |
| indio_dev->channels = chan_info->channels; |
| indio_dev->num_channels = chan_info->num_channels; |
| indio_dev->available_scan_masks = chan_info->scan_masks; |
| indio_dev->masklength = chan_info->num_channels - 1; |
| } |
| |
| static const char * const ad7266_gpio_labels[] = { |
| "AD0", "AD1", "AD2", |
| }; |
| |
| static int ad7266_probe(struct spi_device *spi) |
| { |
| struct ad7266_platform_data *pdata = spi->dev.platform_data; |
| struct iio_dev *indio_dev; |
| struct ad7266_state *st; |
| unsigned int i; |
| int ret; |
| |
| indio_dev = iio_device_alloc(sizeof(*st)); |
| if (indio_dev == NULL) |
| return -ENOMEM; |
| |
| st = iio_priv(indio_dev); |
| |
| st->reg = regulator_get(&spi->dev, "vref"); |
| if (!IS_ERR_OR_NULL(st->reg)) { |
| ret = regulator_enable(st->reg); |
| if (ret) |
| goto error_put_reg; |
| |
| st->vref_uv = regulator_get_voltage(st->reg); |
| } else { |
| /* Use internal reference */ |
| st->vref_uv = 2500000; |
| } |
| |
| if (pdata) { |
| st->fixed_addr = pdata->fixed_addr; |
| st->mode = pdata->mode; |
| st->range = pdata->range; |
| |
| if (!st->fixed_addr) { |
| for (i = 0; i < ARRAY_SIZE(st->gpios); ++i) { |
| st->gpios[i].gpio = pdata->addr_gpios[i]; |
| st->gpios[i].flags = GPIOF_OUT_INIT_LOW; |
| st->gpios[i].label = ad7266_gpio_labels[i]; |
| } |
| ret = gpio_request_array(st->gpios, |
| ARRAY_SIZE(st->gpios)); |
| if (ret) |
| goto error_disable_reg; |
| } |
| } else { |
| st->fixed_addr = true; |
| st->range = AD7266_RANGE_VREF; |
| st->mode = AD7266_MODE_DIFF; |
| } |
| |
| spi_set_drvdata(spi, indio_dev); |
| st->spi = spi; |
| |
| indio_dev->dev.parent = &spi->dev; |
| indio_dev->name = spi_get_device_id(spi)->name; |
| indio_dev->modes = INDIO_DIRECT_MODE; |
| indio_dev->info = &ad7266_info; |
| |
| ad7266_init_channels(indio_dev); |
| |
| /* wakeup */ |
| st->single_xfer[0].rx_buf = &st->data; |
| st->single_xfer[0].len = 2; |
| st->single_xfer[0].cs_change = 1; |
| /* conversion */ |
| st->single_xfer[1].rx_buf = &st->data; |
| st->single_xfer[1].len = 4; |
| st->single_xfer[1].cs_change = 1; |
| /* powerdown */ |
| st->single_xfer[2].tx_buf = &st->data; |
| st->single_xfer[2].len = 1; |
| |
| spi_message_init(&st->single_msg); |
| spi_message_add_tail(&st->single_xfer[0], &st->single_msg); |
| spi_message_add_tail(&st->single_xfer[1], &st->single_msg); |
| spi_message_add_tail(&st->single_xfer[2], &st->single_msg); |
| |
| ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time, |
| &ad7266_trigger_handler, &iio_triggered_buffer_setup_ops); |
| if (ret) |
| goto error_free_gpios; |
| |
| ret = iio_device_register(indio_dev); |
| if (ret) |
| goto error_buffer_cleanup; |
| |
| return 0; |
| |
| error_buffer_cleanup: |
| iio_triggered_buffer_cleanup(indio_dev); |
| error_free_gpios: |
| if (!st->fixed_addr) |
| gpio_free_array(st->gpios, ARRAY_SIZE(st->gpios)); |
| error_disable_reg: |
| if (!IS_ERR_OR_NULL(st->reg)) |
| regulator_disable(st->reg); |
| error_put_reg: |
| if (!IS_ERR_OR_NULL(st->reg)) |
| regulator_put(st->reg); |
| |
| iio_device_free(indio_dev); |
| |
| return ret; |
| } |
| |
| static int ad7266_remove(struct spi_device *spi) |
| { |
| struct iio_dev *indio_dev = spi_get_drvdata(spi); |
| struct ad7266_state *st = iio_priv(indio_dev); |
| |
| iio_device_unregister(indio_dev); |
| iio_triggered_buffer_cleanup(indio_dev); |
| if (!st->fixed_addr) |
| gpio_free_array(st->gpios, ARRAY_SIZE(st->gpios)); |
| if (!IS_ERR_OR_NULL(st->reg)) { |
| regulator_disable(st->reg); |
| regulator_put(st->reg); |
| } |
| iio_device_free(indio_dev); |
| |
| return 0; |
| } |
| |
| static const struct spi_device_id ad7266_id[] = { |
| {"ad7265", 0}, |
| {"ad7266", 0}, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(spi, ad7266_id); |
| |
| static struct spi_driver ad7266_driver = { |
| .driver = { |
| .name = "ad7266", |
| .owner = THIS_MODULE, |
| }, |
| .probe = ad7266_probe, |
| .remove = ad7266_remove, |
| .id_table = ad7266_id, |
| }; |
| module_spi_driver(ad7266_driver); |
| |
| MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); |
| MODULE_DESCRIPTION("Analog Devices AD7266/65 ADC"); |
| MODULE_LICENSE("GPL v2"); |