Re: [PATCH v9 4/8] iio: dac: adi-axi-dac: extend features
From: Nuno Sá
Date: Tue Oct 29 2024 - 04:09:38 EST
On Mon, 2024-10-28 at 22:45 +0100, Angelo Dureghello wrote:
> From: Angelo Dureghello <adureghello@xxxxxxxxxxxx>
>
> Extend AXI-DAC backend with new features required to interface
> to the ad3552r DAC. Mainly, a new compatible string is added to
> support the ad3552r-axi DAC IP, very similar to the generic DAC
> IP but with some customizations to work with the ad3552r.
>
> Then, a series of generic functions has been added to match with
> ad3552r needs. Function names has been kept generic as much as
> possible, to allow re-utilization from other frontend drivers.
>
> Signed-off-by: Angelo Dureghello <adureghello@xxxxxxxxxxxx>
> ---
Hi Angelo,
Small stuff that Jonathan might be able to change while applying... With that:
Reviewed-by: Nuno Sa <nuno.sa@xxxxxxxxxx>
> drivers/iio/dac/adi-axi-dac.c | 256 +++++++++++++++++++++++++++++++++++++++--
> -
> 1 file changed, 242 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/iio/dac/adi-axi-dac.c b/drivers/iio/dac/adi-axi-dac.c
> index 04193a98616e..155d04ca2315 100644
> --- a/drivers/iio/dac/adi-axi-dac.c
> +++ b/drivers/iio/dac/adi-axi-dac.c
> @@ -46,9 +46,28 @@
> #define AXI_DAC_CNTRL_1_REG 0x0044
> #define AXI_DAC_CNTRL_1_SYNC BIT(0)
> #define AXI_DAC_CNTRL_2_REG 0x0048
> +#define AXI_DAC_CNTRL_2_SDR_DDR_N BIT(16)
> +#define AXI_DAC_CNTRL_2_SYMB_8B BIT(14)
> #define ADI_DAC_CNTRL_2_R1_MODE BIT(5)
> +#define AXI_DAC_CNTRL_2_UNSIGNED_DATA BIT(4)
> +#define AXI_DAC_STATUS_1_REG 0x0054
> +#define AXI_DAC_STATUS_2_REG 0x0058
> #define AXI_DAC_DRP_STATUS_REG 0x0074
> #define AXI_DAC_DRP_STATUS_DRP_LOCKED BIT(17)
> +#define AXI_DAC_CUSTOM_RD_REG 0x0080
> +#define AXI_DAC_CUSTOM_WR_REG 0x0084
> +#define AXI_DAC_CUSTOM_WR_DATA_8 GENMASK(23, 16)
> +#define AXI_DAC_CUSTOM_WR_DATA_16 GENMASK(23, 8)
> +#define AXI_DAC_UI_STATUS_REG 0x0088
> +#define AXI_DAC_UI_STATUS_IF_BUSY BIT(4)
> +#define AXI_DAC_CUSTOM_CTRL_REG 0x008C
> +#define AXI_DAC_CUSTOM_CTRL_ADDRESS GENMASK(31, 24)
> +#define AXI_DAC_CUSTOM_CTRL_SYNCED_TRANSFER BIT(2)
> +#define AXI_DAC_CUSTOM_CTRL_STREAM BIT(1)
> +#define AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA BIT(0)
> +
> +#define
> AXI_DAC_CUSTOM_CTRL_STREAM_ENABLE (AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA | \
> + AXI_DAC_CUSTOM_CTRL_STREAM)
>
> /* DAC Channel controls */
> #define AXI_DAC_CHAN_CNTRL_1_REG(c) (0x0400 + (c) * 0x40)
> @@ -63,12 +82,21 @@
> #define AXI_DAC_CHAN_CNTRL_7_REG(c) (0x0418 + (c) * 0x40)
> #define AXI_DAC_CHAN_CNTRL_7_DATA_SEL GENMASK(3, 0)
>
> +#define AXI_DAC_RD_ADDR(x) (BIT(7) | (x))
> +
> /* 360 degrees in rad */
> #define AXI_DAC_2_PI_MEGA 6283190
>
> enum {
> AXI_DAC_DATA_INTERNAL_TONE,
> AXI_DAC_DATA_DMA = 2,
> + AXI_DAC_DATA_INTERNAL_RAMP_16BIT = 11,
> +};
> +
> +struct axi_dac_info {
> + unsigned int version;
> + const struct iio_backend_info *backend_info;
> + bool has_dac_clk;
> };
>
> struct axi_dac_state {
> @@ -79,9 +107,11 @@ struct axi_dac_state {
> * data/variables.
> */
> struct mutex lock;
> + const struct axi_dac_info *info;
> u64 dac_clk;
> u32 reg_config;
> bool int_tone;
> + int dac_clk_rate;
> };
>
> static int axi_dac_enable(struct iio_backend *back)
> @@ -471,6 +501,11 @@ static int axi_dac_data_source_set(struct iio_backend
> *back, unsigned int chan,
> AXI_DAC_CHAN_CNTRL_7_REG(chan),
> AXI_DAC_CHAN_CNTRL_7_DATA_SEL,
> AXI_DAC_DATA_DMA);
> + case IIO_BACKEND_INTERNAL_RAMP_16BIT:
> + return regmap_update_bits(st->regmap,
> + AXI_DAC_CHAN_CNTRL_7_REG(chan),
> + AXI_DAC_CHAN_CNTRL_7_DATA_SEL,
> + AXI_DAC_DATA_INTERNAL_RAMP_16BIT);
> default:
> return -EINVAL;
> }
> @@ -528,6 +563,154 @@ static int axi_dac_reg_access(struct iio_backend *back,
> unsigned int reg,
> return regmap_write(st->regmap, reg, writeval);
> }
>
> +static int axi_dac_ddr_enable(struct iio_backend *back)
> +{
> + struct axi_dac_state *st = iio_backend_get_priv(back);
> +
> + return regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
> + AXI_DAC_CNTRL_2_SDR_DDR_N);
> +}
> +
> +static int axi_dac_ddr_disable(struct iio_backend *back)
> +{
> + struct axi_dac_state *st = iio_backend_get_priv(back);
> +
> + return regmap_set_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
> + AXI_DAC_CNTRL_2_SDR_DDR_N);
> +}
> +
> +static int axi_dac_data_stream_enable(struct iio_backend *back)
> +{
> + struct axi_dac_state *st = iio_backend_get_priv(back);
> +
> + return regmap_set_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
> + AXI_DAC_CUSTOM_CTRL_STREAM_ENABLE);
> +}
> +
> +static int axi_dac_data_stream_disable(struct iio_backend *back)
> +{
> + struct axi_dac_state *st = iio_backend_get_priv(back);
> +
> + return regmap_clear_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
> + AXI_DAC_CUSTOM_CTRL_STREAM_ENABLE);
> +}
> +
> +static int axi_dac_data_transfer_addr(struct iio_backend *back, u32 address)
> +{
> + struct axi_dac_state *st = iio_backend_get_priv(back);
> +
> + if (address > FIELD_MAX(AXI_DAC_CUSTOM_CTRL_ADDRESS))
> + return -EINVAL;
> +
> + /*
> + * Sample register address, when the DAC is configured, or stream
> + * start address when the FSM is in stream state.
> + */
> + return regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
> + AXI_DAC_CUSTOM_CTRL_ADDRESS,
> + FIELD_PREP(AXI_DAC_CUSTOM_CTRL_ADDRESS,
> + address));
> +}
> +
> +static int axi_dac_data_format_set(struct iio_backend *back, unsigned int ch,
> + const struct iio_backend_data_fmt *data)
> +{
> + struct axi_dac_state *st = iio_backend_get_priv(back);
> +
> + switch (data->type) {
> + case IIO_BACKEND_DATA_UNSIGNED:
> + return regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
> + AXI_DAC_CNTRL_2_UNSIGNED_DATA);
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int axi_dac_bus_reg_write_locked(struct iio_backend *back, u32 reg,
> + u32 val, size_t data_size)
nit: this is actually unlocked and needs to be locked from the outside. So,
unlocked could be a better suffix. But more importantly is the extra call to
iio_backend_get_priv(). We can just pass *st directly from the outer function.
> +{
> + struct axi_dac_state *st = iio_backend_get_priv(back);
> + int ret;
> + u32 ival;
> +
> + /*
> + * Both AXI_DAC_CNTRL_2_REG and AXI_DAC_CUSTOM_WR_REG need to know
> + * the data size. So keeping data size control here only,
> + * since data size is mandatory for the current transfer.
> + * DDR state handled separately by specific backend calls,
> + * generally all raw register writes are SDR.
> + */
> + if (data_size == sizeof(u16))
> + ival = FIELD_PREP(AXI_DAC_CUSTOM_WR_DATA_16, val);
> + else
> + ival = FIELD_PREP(AXI_DAC_CUSTOM_WR_DATA_8, val);
> +
> + ret = regmap_write(st->regmap, AXI_DAC_CUSTOM_WR_REG, ival);
> + if (ret)
> + return ret;
> +
> + if (data_size == sizeof(u8))
> + ret = regmap_set_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
> + AXI_DAC_CNTRL_2_SYMB_8B);
> + else
> + ret = regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
> + AXI_DAC_CNTRL_2_SYMB_8B);
> + if (ret)
> + return ret;
> +
> + ret = regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
> + AXI_DAC_CUSTOM_CTRL_ADDRESS,
> + FIELD_PREP(AXI_DAC_CUSTOM_CTRL_ADDRESS,
> reg));
> + if (ret)
> + return ret;
> +
> + ret = regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
> + AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA,
> + AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA);
> + if (ret)
> + return ret;
> +
> + ret = regmap_read_poll_timeout(st->regmap,
> + AXI_DAC_UI_STATUS_REG, ival,
> + FIELD_GET(AXI_DAC_UI_STATUS_IF_BUSY, ival) ==
> 0,
> + 10, 100 * KILO);
> + if (ret == -ETIMEDOUT)
> + dev_err(st->dev, "AXI read timeout\n");
> +
> + /* Cleaning always AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA */
> + return regmap_clear_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
> + AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA);
> +}
> +
> +static int axi_dac_bus_reg_write(struct iio_backend *back, u32 reg,
> + u32 val, size_t data_size)
> +{
> + struct axi_dac_state *st = iio_backend_get_priv(back);
> +
> + guard(mutex)(&st->lock);
> + return axi_dac_bus_reg_write_locked(back, reg, val, data_size);
> +}
> +
Also just realized that the above read()/write() functions could make more sense
in the patch making the device a "bus controller". But well, not that important
I guess.
- Nuno Sá