On Thu, 15 Oct 2015, Marc Andre wrote:
> LTC2617 device (and the other devices from Linear Technology) have
> a different behavior for power down than the Analog Device devices.
> The command must be addressed with the right channel address. Also,
> only a single power down mode (90k to ground) is available.
please update Documentation/ABI/testing/sysfs-bus-iio for the 90k_to_gnd
mode, out_voltageY_powerdown_mode
> This patch adjusts the driver to handle the LTC case specifically.
>
> I decided to implement the different power down modes as a
> separate iio_ext_info structure. An alternative implementation
> would be to set the iio_ext_info structure not const
> and then adjust the enum in the probe() function based on a
> chip_info setting. In my view this would be less ideal because
> it uses more memory for the kernel.
>
> The different addressing is handled with a flag in the chip_info
> structure. Alternatively we could implement a copy of all
> set_powerdown_...() functions. I think this is less nice.
>
> Signed-off-by: Marc Andre <marc.andre@xxxxxxxxxx>
> ---
> drivers/iio/dac/ad5064.c | 120 ++++++++++++++++++++++++++++++++---------------
> 1 file changed, 82 insertions(+), 38 deletions(-)
>
> diff --git a/drivers/iio/dac/ad5064.c b/drivers/iio/dac/ad5064.c
> index a76f4cf..1b89625 100644
> --- a/drivers/iio/dac/ad5064.c
> +++ b/drivers/iio/dac/ad5064.c
> @@ -1,8 +1,8 @@
> /*
> * AD5024, AD5025, AD5044, AD5045, AD5064, AD5064-1, AD5065, AD5628, AD5629R,
> * AD5648, AD5666, AD5668, AD5669R, LTC2606, LTC2607, LTC2609, LTC2616,
> - * LTC2617, LTC2619, LTC2626, LTC2627, LTC2629
> - * Digital to analog converters driver
> + * LTC2617, LTC2619, LTC2626, LTC2627, LTC2629 Digital to analog converters
> + * driver
> *
> * Copyright 2011 Analog Devices Inc.
> *
> @@ -52,10 +52,12 @@
> /**
> * struct ad5064_chip_info - chip specific information
> * @shared_vref: whether the vref supply is shared between channels
> - * @internal_vref: internal reference voltage. 0 if the chip has no internal
> - * vref.
> + * @internal_vref: internal reference voltage. 0 if the chip has no
> + internal vref.
> * @channel: channel specification
> * @num_channels: number of channels
> + * @powerdown_ltc: Use alternative power down addressing as required by
> + * ltc2617 and others.
> */
>
> struct ad5064_chip_info {
> @@ -63,6 +65,7 @@ struct ad5064_chip_info {
> unsigned long internal_vref;
> const struct iio_chan_spec *channels;
> unsigned int num_channels;
> + bool powerdown_ltc;
> };
>
> struct ad5064_state;
> @@ -147,15 +150,21 @@ static int ad5064_write(struct ad5064_state *st, unsigned int cmd,
> static int ad5064_sync_powerdown_mode(struct ad5064_state *st,
> const struct iio_chan_spec *chan)
> {
> - unsigned int val;
> + unsigned int val, address;
> int ret;
>
> - val = (0x1 << chan->address);
> + if (st->chip_info->powerdown_ltc) {
> + val = 0;
> + address = chan->address;
> + } else {
> + address = 0;
> + val = (0x1 << chan->address);
>
> - if (st->pwr_down[chan->channel])
> - val |= st->pwr_down_mode[chan->channel] << 8;
> + if (st->pwr_down[chan->channel])
> + val |= st->pwr_down_mode[chan->channel] << 8;
> + }
>
> - ret = ad5064_write(st, AD5064_CMD_POWERDOWN_DAC, 0, val, 0);
> + ret = ad5064_write(st, AD5064_CMD_POWERDOWN_DAC, address, val, 0);
>
> return ret;
> }
> @@ -166,6 +175,10 @@ static const char * const ad5064_powerdown_modes[] = {
> "three_state",
> };
>
> +static const char * const ltc2617_powerdown_modes[] = {
> + "90kohm_to_gnd",
> +};
> +
> static int ad5064_get_powerdown_mode(struct iio_dev *indio_dev,
> const struct iio_chan_spec *chan)
> {
> @@ -196,6 +209,13 @@ static const struct iio_enum ad5064_powerdown_mode_enum = {
> .set = ad5064_set_powerdown_mode,
> };
>
> +static const struct iio_enum ltc2617_powerdown_mode_enum = {
> + .items = ltc2617_powerdown_modes,
> + .num_items = ARRAY_SIZE(ltc2617_powerdown_modes),
> + .get = ad5064_get_powerdown_mode,
> + .set = ad5064_set_powerdown_mode,
> +};
> +
> static ssize_t ad5064_read_dac_powerdown(struct iio_dev *indio_dev,
> uintptr_t private, const struct iio_chan_spec *chan, char *buf)
> {
> @@ -306,7 +326,19 @@ static const struct iio_chan_spec_ext_info ad5064_ext_info[] = {
> { },
> };
>
> -#define AD5064_CHANNEL(chan, addr, bits, _shift) { \
> +static const struct iio_chan_spec_ext_info ltc2617_ext_info[] = {
> + {
> + .name = "powerdown",
> + .read = ad5064_read_dac_powerdown,
> + .write = ad5064_write_dac_powerdown,
> + .shared = IIO_SEPARATE,
> + },
> + IIO_ENUM("powerdown_mode", IIO_SEPARATE, <c2617_powerdown_mode_enum),
> + IIO_ENUM_AVAILABLE("powerdown_mode", <c2617_powerdown_mode_enum),
> + { },
> +};
> +
> +#define AD5064_CHANNEL(chan, addr, bits, _shift, _ext_info) { \
> .type = IIO_VOLTAGE, \
> .indexed = 1, \
> .output = 1, \
> @@ -320,38 +352,41 @@ static const struct iio_chan_spec_ext_info ad5064_ext_info[] = {
> .storagebits = 16, \
> .shift = (_shift), \
> }, \
> - .ext_info = ad5064_ext_info, \
> + .ext_info = (_ext_info), \
> }
>
> -#define DECLARE_AD5064_CHANNELS(name, bits, shift) \
> +#define DECLARE_AD5064_CHANNELS(name, bits, shift, ext_info) \
> const struct iio_chan_spec name[] = { \
> - AD5064_CHANNEL(0, 0, bits, shift), \
> - AD5064_CHANNEL(1, 1, bits, shift), \
> - AD5064_CHANNEL(2, 2, bits, shift), \
> - AD5064_CHANNEL(3, 3, bits, shift), \
> - AD5064_CHANNEL(4, 4, bits, shift), \
> - AD5064_CHANNEL(5, 5, bits, shift), \
> - AD5064_CHANNEL(6, 6, bits, shift), \
> - AD5064_CHANNEL(7, 7, bits, shift), \
> + AD5064_CHANNEL(0, 0, bits, shift, ext_info), \
> + AD5064_CHANNEL(1, 1, bits, shift, ext_info), \
> + AD5064_CHANNEL(2, 2, bits, shift, ext_info), \
> + AD5064_CHANNEL(3, 3, bits, shift, ext_info), \
> + AD5064_CHANNEL(4, 4, bits, shift, ext_info), \
> + AD5064_CHANNEL(5, 5, bits, shift, ext_info), \
> + AD5064_CHANNEL(6, 6, bits, shift, ext_info), \
> + AD5064_CHANNEL(7, 7, bits, shift, ext_info), \
> }
>
> -#define DECLARE_AD5065_CHANNELS(name, bits, shift) \
> +#define DECLARE_AD5065_CHANNELS(name, bits, shift, ext_info) \
> const struct iio_chan_spec name[] = { \
> - AD5064_CHANNEL(0, 0, bits, shift), \
> - AD5064_CHANNEL(1, 3, bits, shift), \
> + AD5064_CHANNEL(0, 0, bits, shift, ext_info), \
> + AD5064_CHANNEL(1, 3, bits, shift, ext_info), \
> }
>
> -static DECLARE_AD5064_CHANNELS(ad5024_channels, 12, 8);
> -static DECLARE_AD5064_CHANNELS(ad5044_channels, 14, 6);
> -static DECLARE_AD5064_CHANNELS(ad5064_channels, 16, 4);
> +static DECLARE_AD5064_CHANNELS(ad5024_channels, 12, 8, ad5064_ext_info);
> +static DECLARE_AD5064_CHANNELS(ad5044_channels, 14, 6, ad5064_ext_info);
> +static DECLARE_AD5064_CHANNELS(ad5064_channels, 16, 4, ad5064_ext_info);
> +
> +static DECLARE_AD5065_CHANNELS(ad5025_channels, 12, 8, ad5064_ext_info);
> +static DECLARE_AD5065_CHANNELS(ad5045_channels, 14, 6, ad5064_ext_info);
> +static DECLARE_AD5065_CHANNELS(ad5065_channels, 16, 4, ad5064_ext_info);
>
> -static DECLARE_AD5065_CHANNELS(ad5025_channels, 12, 8);
> -static DECLARE_AD5065_CHANNELS(ad5045_channels, 14, 6);
> -static DECLARE_AD5065_CHANNELS(ad5065_channels, 16, 4);
> +static DECLARE_AD5064_CHANNELS(ad5629_channels, 12, 4, ad5064_ext_info);
> +static DECLARE_AD5064_CHANNELS(ad5669_channels, 16, 0, ad5064_ext_info);
>
> -static DECLARE_AD5064_CHANNELS(ad5629_channels, 12, 4);
> -static DECLARE_AD5064_CHANNELS(ltc2617_channels, 14, 2);
> -static DECLARE_AD5064_CHANNELS(ad5669_channels, 16, 0);
> +static DECLARE_AD5064_CHANNELS(ltc2607_channels, 16, 0, ltc2617_ext_info);
> +static DECLARE_AD5064_CHANNELS(ltc2617_channels, 14, 2, ltc2617_ext_info);
> +static DECLARE_AD5064_CHANNELS(ltc2627_channels, 12, 4, ltc2617_ext_info);
>
> static const struct ad5064_chip_info ad5064_chip_info_tbl[] = {
> [ID_AD5024] = {
> @@ -464,56 +499,65 @@ static const struct ad5064_chip_info ad5064_chip_info_tbl[] = {
> [ID_LTC2606] = {
> .shared_vref = true,
> .internal_vref = 0,
> - .channels = ad5669_channels,
> + .channels = ltc2607_channels,
> .num_channels = 1,
> + .powerdown_ltc = true,
> },
> [ID_LTC2607] = {
> .shared_vref = true,
> .internal_vref = 0,
> - .channels = ad5669_channels,
> + .channels = ltc2607_channels,
> .num_channels = 2,
> + .powerdown_ltc = true,
> },
> [ID_LTC2609] = {
> .shared_vref = false,
> .internal_vref = 0,
> - .channels = ad5669_channels,
> + .channels = ltc2607_channels,
> .num_channels = 4,
> + .powerdown_ltc = true,
> },
> [ID_LTC2616] = {
> .shared_vref = true,
> .internal_vref = 0,
> .channels = ltc2617_channels,
> .num_channels = 1,
> + .powerdown_ltc = true,
> },
> [ID_LTC2617] = {
> .shared_vref = true,
> .internal_vref = 0,
> .channels = ltc2617_channels,
> .num_channels = 2,
> + .powerdown_ltc = true,
> },
> [ID_LTC2619] = {
> .shared_vref = false,
> .internal_vref = 0,
> .channels = ltc2617_channels,
> .num_channels = 4,
> + .powerdown_ltc = true,
> },
> [ID_LTC2626] = {
> .shared_vref = true,
> .internal_vref = 0,
> - .channels = ad5629_channels,
> + .channels = ltc2627_channels,
> .num_channels = 1,
> + .powerdown_ltc = true,
> },
> [ID_LTC2627] = {
> .shared_vref = true,
> .internal_vref = 0,
> - .channels = ad5629_channels,
> + .channels = ltc2627_channels,
> .num_channels = 2,
> + .powerdown_ltc = true,
> },
> [ID_LTC2629] = {
> .shared_vref = false,
> .internal_vref = 0,
> - .channels = ad5629_channels,
> + .channels = ltc2627_channels,
> .num_channels = 4,
> + .powerdown_ltc = true,
> },
> };
>
>
--
Peter Meerwald
+43-664-2444418 (mobile)
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