Re: [PATCH v2 4/4] iio: adc: ad7923: Add support for the ad7908/ad7918/ad7928
From: Ardelean, Alexandru
Date: Wed Dec 11 2019 - 02:46:30 EST
On Tue, 2019-12-10 at 12:08 -0300, Daniel Junho wrote:
> [External]
>
> The ad7928 is software compatible with the ad7923.
> The ad7908 and ad7918 are the 8 and 10-bit versions of the ad7928.
>
The patch looks good.
Comments mostly about namimg.
One about channel numbers.
> Signed-off-by: Daniel Junho <djunho@xxxxxxxxx>
> ---
> drivers/iio/adc/ad7923.c | 62 +++++++++++++++++++++++++++++++++-------
> 1 file changed, 51 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/iio/adc/ad7923.c b/drivers/iio/adc/ad7923.c
> index 6d56fa0b9e30..ae807fcaad76 100644
> --- a/drivers/iio/adc/ad7923.c
> +++ b/drivers/iio/adc/ad7923.c
> @@ -1,6 +1,6 @@
> // SPDX-License-Identifier: GPL-2.0-only
> /*
> - * AD7904/AD7914/AD7923/AD7924 SPI ADC driver
> + * AD7904/AD7914/AD7923/AD7924/AD7908/AD7918/AD7928 SPI ADC driver
> *
> * Copyright 2011 Analog Devices Inc (from AD7923 Driver)
> * Copyright 2012 CS Systemes d'Information
> @@ -29,11 +29,14 @@
> #define AD7923_PM_MODE_AS (1) /* auto shutdown */
> #define AD7923_PM_MODE_FS (2) /* full shutdown */
> #define AD7923_PM_MODE_OPS (3) /* normal operation */
> -#define AD7923_SEQUENCE_OFF (0) /* no sequence fonction
> */
> -#define AD7923_SEQUENCE_PROTECT (2) /* no interrupt
> write cycle */
> -#define AD7923_SEQUENCE_ON (3) /* continuous sequence */
>
> -#define AD7923_MAX_CHAN 4
> +#define AD7923_SEQUENCE_OFF (0x00) /* no sequence function
> */
> +#define AD7923_SEQUENCE_SHADOW (0x01) /* use the shadow
> register
> + * for programming
> + * (only AD7908/7918/7928)
[1] Since this reg is only available on these 3 chips, you could rename
this to AD7908_SEQUENCE_SHADOW and use it for these 3 chips only.
That way, you don't need to mention via comment "(only AD7908/7918/7928)"
> + */
> +#define AD7923_SEQUENCE_PROTECT (0x10) /* no interrupt
> write cycle */
> +#define AD7923_SEQUENCE_ON (0x11) /* continuous sequence */
>
> #define AD7923_PM_MODE_WRITE(mode) ((mode) << 4) /* write mode */
> #define AD7923_CHANNEL_WRITE(channel) ((channel) << 6) /* write
> channel */
> @@ -74,6 +77,9 @@ enum ad7923_id {
> AD7904,
> AD7914,
> AD7924,
> + AD7908,
> + AD7918,
> + AD7928
> };
>
> #define AD7923_V_CHAN(index, bits) \
> @@ -93,7 +99,7 @@ enum ad7923_id {
> }, \
> }
>
> -#define DECLARE_AD7923_CHANNELS(name, bits) \
> +#define DECLARE_AD7923_4CHANNELS(name, bits) \
> const struct iio_chan_spec name ## _channels[] = { \
> AD7923_V_CHAN(0, bits), \
> AD7923_V_CHAN(1, bits), \
> @@ -102,9 +108,25 @@ const struct iio_chan_spec name ## _channels[] = { \
> IIO_CHAN_SOFT_TIMESTAMP(4), \
> }
>
> -static DECLARE_AD7923_CHANNELS(ad7904, 8);
> -static DECLARE_AD7923_CHANNELS(ad7914, 10);
> -static DECLARE_AD7923_CHANNELS(ad7924, 12);
> +#define DECLARE_AD7923_8CHANNELS(name, bits) \
Same comments as [1], you could leave DECLARE_AD7923_CHANNELS and declare
DECLARE_AD7908_CHANNELS which has 8 channels and use for the 3 new chips.
> +const struct iio_chan_spec name ## _channels[] = { \
> + AD7923_V_CHAN(0, bits), \
> + AD7923_V_CHAN(1, bits), \
> + AD7923_V_CHAN(2, bits), \
> + AD7923_V_CHAN(3, bits), \
> + AD7923_V_CHAN(4, bits), \
> + AD7923_V_CHAN(5, bits), \
> + AD7923_V_CHAN(6, bits), \
> + AD7923_V_CHAN(7, bits), \
> + IIO_CHAN_SOFT_TIMESTAMP(8), \
> +}
> +
> +static DECLARE_AD7923_4CHANNELS(ad7904, 8);
> +static DECLARE_AD7923_4CHANNELS(ad7914, 10);
> +static DECLARE_AD7923_4CHANNELS(ad7924, 12);
> +static DECLARE_AD7923_8CHANNELS(ad7908, 8);
> +static DECLARE_AD7923_8CHANNELS(ad7918, 10);
> +static DECLARE_AD7923_8CHANNELS(ad7928, 12);
>
> static const struct ad7923_chip_info ad7923_chip_info[] = {
> [AD7904] = {
> @@ -119,6 +141,18 @@ static const struct ad7923_chip_info
> ad7923_chip_info[] = {
> .channels = ad7924_channels,
> .num_channels = ARRAY_SIZE(ad7924_channels),
> },
> + [AD7908] = {
> + .channels = ad7908_channels,
> + .num_channels = ARRAY_SIZE(ad7908_channels),
> + },
> + [AD7918] = {
> + .channels = ad7918_channels,
> + .num_channels = ARRAY_SIZE(ad7918_channels),
> + },
> + [AD7928] = {
> + .channels = ad7928_channels,
> + .num_channels = ARRAY_SIZE(ad7928_channels),
> + },
> };
>
> /**
> @@ -131,7 +165,7 @@ static int ad7923_update_scan_mode(struct iio_dev
> *indio_dev,
> int i, cmd, len;
>
> len = 0;
> - for_each_set_bit(i, active_scan_mask, AD7923_MAX_CHAN) {
> + for_each_set_bit(i, active_scan_mask, indio_dev->num_channels - 1)
I got the idea about 'indio_dev->num_channel - 1'.
This makes the assumption that the number of IIO channels is always HW-
channels + 1 timestamp channel [which for now is true].
I'm not sure if this is ok.
I think Jonathan would be a bit better here to comment.
> {
> cmd = AD7923_WRITE_CR | AD7923_CHANNEL_WRITE(i) |
> AD7923_SEQUENCE_WRITE(AD7923_SEQUENCE_OFF) |
> st->settings;
> @@ -344,6 +378,9 @@ static const struct spi_device_id ad7923_id[] = {
> {"ad7914", AD7914},
> {"ad7923", AD7924},
> {"ad7924", AD7924},
> + {"ad7908", AD7908},
> + {"ad7918", AD7918},
> + {"ad7928", AD7928},
> {}
> };
> MODULE_DEVICE_TABLE(spi, ad7923_id);
> @@ -353,6 +390,9 @@ static const struct of_device_id ad7923_of_match[] =
> {
> { .compatible = "adi,ad7914", },
> { .compatible = "adi,ad7923", },
> { .compatible = "adi,ad7924", },
> + { .compatible = "adi,ad7908", },
> + { .compatible = "adi,ad7918", },
> + { .compatible = "adi,ad7928", },
> { },
> };
> MODULE_DEVICE_TABLE(of, ad7923_of_match);
> @@ -370,5 +410,5 @@ module_spi_driver(ad7923_driver);
>
> MODULE_AUTHOR("Michael Hennerich <michael.hennerich@xxxxxxxxxx>");
> MODULE_AUTHOR("Patrick Vasseur <patrick.vasseur@xxxxxx>");
> -MODULE_DESCRIPTION("Analog Devices AD7904/AD7914/AD7923/AD7924 ADC");
> +MODULE_DESCRIPTION("Analog Devices
> AD7904/AD7914/AD7923/AD7924/AD7908/AD7918/AD7928 ADC");
This description is becoming long.
Maybe simplify to
MODULE_DESCRIPTION("Analog Devices AD7923 and similar ADC");
> MODULE_LICENSE("GPL v2");