[PATCH 1/4] iio: adc: ad7606: Add support for AD7606B ADC
Jonathan Cameron
jic23 at kernel.org
Mon Aug 5 15:46:30 UTC 2019
On Fri, 2 Aug 2019 13:03:01 +0300
Beniamin Bia <beniamin.bia at analog.com> wrote:
> From: Stefan Popa <stefan.popa at analog.com>
>
> The AD7606B is a 16-bit ADC that supports simultaneous sampling of 8
> channels. It is pin compatible to AD7606, but adds extra modes by
> writing to the register map.
>
> The AD7606B can be configured to work in software mode by setting all
> oversampling pins to high. This mode is selected by default.
> The oversampling ratio is configured from the OS_MODE register (address
> 0x08) with the addition of OS=128 and OS=256 that were not available in
> hardware mode.
>
> The device is configured to output data on a single spi channel, but this
> configuration must be done right after restart. That is why the delay was
> removed for devices which doesn't require it.
>
> Moreover, in software mode, the range gpio has no longer its function.
> Instead, the scale can be configured individually for each channel from
> the RANGE_CH registers (address 0x03 to 0x06). Besides the already
> supported ±10 V and ±5 V ranges, software mode can also accommodate the
> ±2.5 V range.
>
> Signed-off-by: Stefan Popa <stefan.popa at analog.com>
> Co-developed-by: Beniamin Bia <beniamin.bia at analog.com>
> Signed-off-by: Beniamin Bia <beniamin.bia at analog.com>
This looks fine to me. I'll pick it up (if no other comments)
when you've tidied up the issues Rob raises for the DT bindings.
Thanks,
Jonathan
> ---
> drivers/iio/adc/ad7606.c | 13 ++++-
> drivers/iio/adc/ad7606.h | 4 ++
> drivers/iio/adc/ad7606_spi.c | 107 +++++++++++++++++++++++++++++++++++
> 3 files changed, 122 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c
> index ed2d08437e5d..f5ba94c03a8d 100644
> --- a/drivers/iio/adc/ad7606.c
> +++ b/drivers/iio/adc/ad7606.c
> @@ -410,12 +410,19 @@ static const struct ad7606_chip_info ad7606_chip_info_tbl[] = {
> .oversampling_avail = ad7606_oversampling_avail,
> .oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
> },
> + [ID_AD7606B] = {
> + .channels = ad7606_channels,
> + .num_channels = 9,
> + .oversampling_avail = ad7606_oversampling_avail,
> + .oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
> + },
> [ID_AD7616] = {
> .channels = ad7616_channels,
> .num_channels = 17,
> .oversampling_avail = ad7616_oversampling_avail,
> .oversampling_num = ARRAY_SIZE(ad7616_oversampling_avail),
> .os_req_reset = true,
> + .init_delay_ms = 15,
> },
> };
>
> @@ -631,8 +638,10 @@ int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
> dev_warn(st->dev, "failed to RESET: no RESET GPIO specified\n");
>
> /* AD7616 requires al least 15ms to reconfigure after a reset */
> - if (msleep_interruptible(15))
> - return -ERESTARTSYS;
> + if (st->chip_info->init_delay_ms) {
> + if (msleep_interruptible(st->chip_info->init_delay_ms))
> + return -ERESTARTSYS;
> + }
>
> st->write_scale = ad7606_write_scale_hw;
> st->write_os = ad7606_write_os_hw;
> diff --git a/drivers/iio/adc/ad7606.h b/drivers/iio/adc/ad7606.h
> index eeaaa8b905db..9350ef1f63b5 100644
> --- a/drivers/iio/adc/ad7606.h
> +++ b/drivers/iio/adc/ad7606.h
> @@ -46,6 +46,8 @@
> * oversampling ratios.
> * @oversampling_num number of elements stored in oversampling_avail array
> * @os_req_reset some devices require a reset to update oversampling
> + * @init_delay_ms required delay in miliseconds for initialization
> + * after a restart
> */
> struct ad7606_chip_info {
> const struct iio_chan_spec *channels;
> @@ -53,6 +55,7 @@ struct ad7606_chip_info {
> const unsigned int *oversampling_avail;
> unsigned int oversampling_num;
> bool os_req_reset;
> + unsigned long init_delay_ms;
> };
>
> /**
> @@ -155,6 +158,7 @@ enum ad7606_supported_device_ids {
> ID_AD7606_8,
> ID_AD7606_6,
> ID_AD7606_4,
> + ID_AD7606B,
> ID_AD7616,
> };
>
> diff --git a/drivers/iio/adc/ad7606_spi.c b/drivers/iio/adc/ad7606_spi.c
> index 98ed52b74507..070ee7e31e2c 100644
> --- a/drivers/iio/adc/ad7606_spi.c
> +++ b/drivers/iio/adc/ad7606_spi.c
> @@ -31,6 +31,20 @@
> /* The range of the channel is stored on 2 bits*/
> #define AD7616_RANGE_CH_MSK(ch) (0b11 << (((ch) & 0b11) * 2))
> #define AD7616_RANGE_CH_MODE(ch, mode) ((mode) << ((((ch) & 0b11)) * 2))
> +
> +#define AD7606_CONFIGURATION_REGISTER 0x02
> +#define AD7606_SINGLE_DOUT 0x0
> +
> +/*
> + * Range for AD7606B channels are stored in registers starting with address 0x3.
> + * Each register stores range for 2 channels(4 bits per channel).
> + */
> +#define AD7606_RANGE_CH_MSK(ch) (GENMASK(3, 0) << (4 * ((ch) & 0x1)))
> +#define AD7606_RANGE_CH_MODE(ch, mode) \
> + ((GENMASK(3, 0) & mode) << (4 * ((ch) & 0x1)))
> +#define AD7606_RANGE_CH_ADDR(ch) (0x03 + ((ch) >> 1))
> +#define AD7606_OS_MODE 0x08
> +
> static const struct iio_chan_spec ad7616_sw_channels[] = {
> IIO_CHAN_SOFT_TIMESTAMP(16),
> AD7616_CHANNEL(0),
> @@ -51,6 +65,22 @@ static const struct iio_chan_spec ad7616_sw_channels[] = {
> AD7616_CHANNEL(15),
> };
>
> +static const struct iio_chan_spec ad7606B_sw_channels[] = {
> + IIO_CHAN_SOFT_TIMESTAMP(8),
> + AD7616_CHANNEL(0),
> + AD7616_CHANNEL(1),
> + AD7616_CHANNEL(2),
> + AD7616_CHANNEL(3),
> + AD7616_CHANNEL(4),
> + AD7616_CHANNEL(5),
> + AD7616_CHANNEL(6),
> + AD7616_CHANNEL(7),
> +};
> +
> +static const unsigned int ad7606B_oversampling_avail[9] = {
> + 1, 2, 4, 8, 16, 32, 64, 128, 256
> +};
> +
> static u16 ad7616_spi_rd_wr_cmd(int addr, char isWriteOp)
> {
> /*
> @@ -60,6 +90,16 @@ static u16 ad7616_spi_rd_wr_cmd(int addr, char isWriteOp)
> return ((addr & 0x7F) << 1) | ((isWriteOp & 0x1) << 7);
> }
>
> +static u16 ad7606B_spi_rd_wr_cmd(int addr, char isWriteOp)
> +{
> + /*
> + * The address of register consists of one bit which
> + * specifies a read command placed bit 6, followed by
> + * 6 bits of address.
> + */
> + return (addr & 0x3F) | (((~isWriteOp) & 0x1) << 6);
> +}
> +
> static int ad7606_spi_read_block(struct device *dev,
> int count, void *buf)
> {
> @@ -169,6 +209,23 @@ static int ad7616_write_os_sw(struct iio_dev *indio_dev, int val)
> AD7616_OS_MASK, val << 2);
> }
>
> +static int ad7606_write_scale_sw(struct iio_dev *indio_dev, int ch, int val)
> +{
> + struct ad7606_state *st = iio_priv(indio_dev);
> +
> + return ad7606_spi_write_mask(st,
> + AD7606_RANGE_CH_ADDR(ch),
> + AD7606_RANGE_CH_MSK(ch),
> + AD7606_RANGE_CH_MODE(ch, val));
> +}
> +
> +static int ad7606_write_os_sw(struct iio_dev *indio_dev, int val)
> +{
> + struct ad7606_state *st = iio_priv(indio_dev);
> +
> + return ad7606_spi_reg_write(st, AD7606_OS_MODE, val);
> +}
> +
> static int ad7616_sw_mode_config(struct iio_dev *indio_dev)
> {
> struct ad7606_state *st = iio_priv(indio_dev);
> @@ -189,6 +246,42 @@ static int ad7616_sw_mode_config(struct iio_dev *indio_dev)
> AD7616_BURST_MODE | AD7616_SEQEN_MODE);
> }
>
> +static int ad7606B_sw_mode_config(struct iio_dev *indio_dev)
> +{
> + struct ad7606_state *st = iio_priv(indio_dev);
> + unsigned long os[3] = {1};
> +
> + /*
> + * Software mode is enabled when all three oversampling
> + * pins are set to high. If oversampling gpios are defined
> + * in the device tree, then they need to be set to high,
> + * otherwise, they must be hardwired to VDD
> + */
> + if (st->gpio_os) {
> + gpiod_set_array_value(ARRAY_SIZE(os),
> + st->gpio_os->desc, st->gpio_os->info, os);
> + }
> + /* OS of 128 and 256 are available only in software mode */
> + st->oversampling_avail = ad7606B_oversampling_avail;
> + st->num_os_ratios = ARRAY_SIZE(ad7606B_oversampling_avail);
> +
> + st->write_scale = ad7606_write_scale_sw;
> + st->write_os = &ad7606_write_os_sw;
> +
> + /* Configure device spi to output on a single channel */
> + st->bops->reg_write(st,
> + AD7606_CONFIGURATION_REGISTER,
> + AD7606_SINGLE_DOUT);
> +
> + /*
> + * Scale can be configured individually for each channel
> + * in software mode.
> + */
> + indio_dev->channels = ad7606B_sw_channels;
> +
> + return 0;
> +}
> +
> static const struct ad7606_bus_ops ad7606_spi_bops = {
> .read_block = ad7606_spi_read_block,
> };
> @@ -202,6 +295,15 @@ static const struct ad7606_bus_ops ad7616_spi_bops = {
> .sw_mode_config = ad7616_sw_mode_config,
> };
>
> +static const struct ad7606_bus_ops ad7606B_spi_bops = {
> + .read_block = ad7606_spi_read_block,
> + .reg_read = ad7606_spi_reg_read,
> + .reg_write = ad7606_spi_reg_write,
> + .write_mask = ad7606_spi_write_mask,
> + .rd_wr_cmd = ad7606B_spi_rd_wr_cmd,
> + .sw_mode_config = ad7606B_sw_mode_config,
> +};
> +
> static int ad7606_spi_probe(struct spi_device *spi)
> {
> const struct spi_device_id *id = spi_get_device_id(spi);
> @@ -211,6 +313,9 @@ static int ad7606_spi_probe(struct spi_device *spi)
> case ID_AD7616:
> bops = &ad7616_spi_bops;
> break;
> + case ID_AD7606B:
> + bops = &ad7606B_spi_bops;
> + break;
> default:
> bops = &ad7606_spi_bops;
> break;
> @@ -226,6 +331,7 @@ static const struct spi_device_id ad7606_id_table[] = {
> { "ad7606-4", ID_AD7606_4 },
> { "ad7606-6", ID_AD7606_6 },
> { "ad7606-8", ID_AD7606_8 },
> + { "ad7606b", ID_AD7606B },
> { "ad7616", ID_AD7616 },
> {}
> };
> @@ -236,6 +342,7 @@ static const struct of_device_id ad7606_of_match[] = {
> { .compatible = "adi,ad7606-4" },
> { .compatible = "adi,ad7606-6" },
> { .compatible = "adi,ad7606-8" },
> + { .compatible = "adi,ad7606b" },
> { .compatible = "adi,ad7616" },
> { },
> };
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