On Thu, 19 Sep 2024 11:20:02 +0200
Angelo Dureghello <adureghello@xxxxxxxxxxxx> 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 serie 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,
A few things in addition to Nuno's review.
> ---
> drivers/iio/dac/adi-axi-dac.c | 274 ++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 265 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/iio/dac/adi-axi-dac.c b/drivers/iio/dac/adi-axi-dac.c
> index b8b4171b8043..3ca3a14c575b 100644
> --- a/drivers/iio/dac/adi-axi-dac.c
> +++ b/drivers/iio/dac/adi-axi-dac.c
> @@ -44,11 +44,34 @@
> #define AXI_DAC_RSTN_MMCM_RSTN BIT(1)
> #define AXI_DAC_RSTN_RSTN BIT(0)
> #define AXI_DAC_REG_CNTRL_1 0x0044
> +#define AXI_DAC_EXT_SYNC_ARM BIT(1)
> +#define AXI_DAC_EXT_SYNC_DISARM BIT(2)
Probably want some sort of order in here! Either do highest
to lowest bit or the other way around. Not a mixture.
I should probably have moaned about this earlier, but naming these
defines to make it clear what is the register address and which
fields belong to that register. Right now that's not easy to tell
for most of these and means that more effort is needed in review
to check values are written to the relevant register and not some
other one.
Perhaps a precursor patch to clean that up would be a good idea.
(or do it right for the new stuff and chase this with a patch tidying
up the existing registers).
The exisint defines seem to have _REG_ in the middle which sort
of does this role but then the fields are not associated with the
register.
E.g. this one should be something like
#define AXI_DAC_FIELD_CNTRL_1_EXT_SYNC_ARM BIT(1)
More common would be to move _REG_ to the end and then just
have fields as the ones that aren't _REG
> #define AXI_DAC_SYNC BIT(0)
> #define AXI_DAC_REG_CNTRL_2 0x0048
> +#define AXI_DAC_SDR_DDR_N BIT(16)
> +#define AXI_DAC_SYMB_8B BIT(14)
> #define ADI_DAC_R1_MODE BIT(5)
Oddity of tabs vs spaces here that should be consistent.
> +#define AXI_DAC_UNSIGNED_DATA BIT(4)
> +#define AXI_DAC_REG_STATUS_1 0x54
> +#define AXI_DAC_REG_STATUS_2 0x58
> #define AXI_DAC_DRP_STATUS 0x0074
> #define AXI_DAC_DRP_LOCKED BIT(17)
> +#define AXI_DAC_CNTRL_DATA_RD 0x0080
Prior cases have _REG_ for the registers, this one doesn't.
> +#define AXI_DAC_DATA_RD_8 GENMASK(7, 0)
> +#define AXI_DAC_DATA_RD_16 GENMASK(15, 0)
> +#define AXI_DAC_CNTRL_DATA_WR 0x0084
> +#define AXI_DAC_DATA_WR_8 GENMASK(23, 16)
> +#define AXI_DAC_DATA_WR_16 GENMASK(23, 8)
Huh. interesting IP, it's aligned one way for read path and the opposite
for write. I bet that never introduces any bugs :)
I'd started commenting the DATA_RD cases seemed obvious enough not
to need defines before I read on a few lines!
> +#define AXI_DAC_UI_STATUS 0x0088
> +#define AXI_DAC_BUSY BIT(4)
> +#define AXI_DAC_REG_CUSTOM_CTRL 0x008C
> +#define AXI_DAC_ADDRESS GENMASK(31, 24)
> +#define AXI_DAC_SYNCED_TRANSFER BIT(2)
> +#define AXI_DAC_STREAM BIT(1)
> +#define AXI_DAC_TRANSFER_DATA BIT(0)
> +static int axi_dac_bus_reg_write(struct iio_backend *back, u32 reg,
> + unsigned int val, size_t data_size)
> +{
> + struct axi_dac_state *st = iio_backend_get_priv(back);
> +
> + switch (st->info->bus_type) {
> + case AXI_DAC_BUS_TYPE_DDR_QSPI: {
> + int ret;
> + u32 ival;
> +
> + if (data_size == 2)
> + ival = FIELD_PREP(AXI_DAC_DATA_WR_16, val);
> + else
> + ival = FIELD_PREP(AXI_DAC_DATA_WR_8, val);
> +
> + ret = regmap_write(st->regmap, AXI_DAC_CNTRL_DATA_WR, ival);
> + if (ret)
> + return ret;
> +
> + /*
> + * Both REG_CNTRL_2 and AXI_DAC_CNTRL_DATA_WR 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 == 1)
> + ret = regmap_set_bits(st->regmap, AXI_DAC_REG_CNTRL_2,
> + AXI_DAC_SYMB_8B);
> + else
> + ret = regmap_clear_bits(st->regmap, AXI_DAC_REG_CNTRL_2,
> + AXI_DAC_SYMB_8B);
> + if (ret)
> + return ret;
> +
> + ret = regmap_update_bits(st->regmap, AXI_DAC_REG_CUSTOM_CTRL,
> + AXI_DAC_ADDRESS,
> + FIELD_PREP(AXI_DAC_ADDRESS, reg));
> + if (ret)
> + return ret;
> +
> + ret = regmap_update_bits(st->regmap, AXI_DAC_REG_CUSTOM_CTRL,
> + AXI_DAC_TRANSFER_DATA,
> + AXI_DAC_TRANSFER_DATA);
> + if (ret)
> + return ret;
> +
> + ret = regmap_read_poll_timeout(st->regmap,
> + AXI_DAC_REG_CUSTOM_CTRL, ival,
> + ival & AXI_DAC_TRANSFER_DATA,
> + 10, 100 * KILO);
> + if (ret)
> + return ret;
> +
> + return regmap_clear_bits(st->regmap, AXI_DAC_REG_CUSTOM_CTRL,
> + AXI_DAC_TRANSFER_DATA);
> + }
> + default:
> + return -EOPNOTSUPP;
> + }
> +}
> +
> +static int axi_dac_bus_reg_read(struct iio_backend *back, u32 reg,
> + unsigned int *val, size_t data_size)
> +{
> + struct axi_dac_state *st = iio_backend_get_priv(back);
> +
> + switch (st->info->bus_type) {
> + case AXI_DAC_BUS_TYPE_DDR_QSPI: {
> + int ret;
> + u32 bval;
> +
> + ret = axi_dac_bus_reg_write(back, AXI_DAC_RD_ADDR(reg), 0,
> + data_size);
> + if (ret)
So the data size is in the write of the register not the read. That seems odd.
I guess this is about setting the bit that says how bit the read is going to be?
Maybe a comment would help here.
> + return ret;
> +
> + ret = regmap_read_poll_timeout(st->regmap, AXI_DAC_UI_STATUS,
> + bval, bval != AXI_DAC_BUSY,
> + 10, 100);
> + if (ret)
> + return ret;
> +
> + return regmap_read(st->regmap, AXI_DAC_CNTRL_DATA_RD, val);
I supposed datasize doesn't strictly matter here, but for ease of readability
I'd do FIELD_GET() to pull out only what was requested.
> + }
> + default:
> + return -EOPNOTSUPP;
> + }
> +}
> +
> static const struct iio_backend_ops axi_dac_generic_ops = {
> .enable = axi_dac_enable,
> .disable = axi_dac_disable,
> + .read_raw = axi_dac_read_raw,
> .request_buffer = axi_dac_request_buffer,
> .free_buffer = axi_dac_free_buffer,
> .extend_chan_spec = axi_dac_extend_chan,
> @@ -528,6 +768,14 @@ static const struct iio_backend_ops axi_dac_generic_ops = {
> .ext_info_get = axi_dac_ext_info_get,
> .data_source_set = axi_dac_data_source_set,
> .set_sample_rate = axi_dac_set_sample_rate,
> + .ext_sync_enable = axi_dac_ext_sync_enable,
> + .ext_sync_disable = axi_dac_ext_sync_disable,
> + .ddr_enable = axi_dac_ddr_enable,
> + .ddr_disable = axi_dac_ddr_disable,
> + .buffer_enable = axi_dac_buffer_enable,
> + .buffer_disable = axi_dac_buffer_disable,
> + .data_format_set = axi_dac_data_format_set,
> + .data_transfer_addr = axi_dac_data_transfer_addr,
> .debugfs_reg_access = iio_backend_debugfs_ptr(axi_dac_reg_access),
> };
>
> @@ -545,7 +793,6 @@ static const struct regmap_config axi_dac_regmap_config = {
>
> static int axi_dac_probe(struct platform_device *pdev)
> {
> - const unsigned int *expected_ver;
> struct axi_dac_state *st;
> void __iomem *base;
> unsigned int ver;
> @@ -556,8 +803,8 @@ static int axi_dac_probe(struct platform_device *pdev)
> if (!st)
> return -ENOMEM;
>
> - expected_ver = device_get_match_data(&pdev->dev);
> - if (!expected_ver)
> + st->info = device_get_match_data(&pdev->dev);
> + if (!st->info)
> return -ENODEV;
>
> clk = devm_clk_get_enabled(&pdev->dev, NULL);
> @@ -588,12 +835,13 @@ static int axi_dac_probe(struct platform_device *pdev)
> if (ret)
> return ret;
>
> - if (ADI_AXI_PCORE_VER_MAJOR(ver) != ADI_AXI_PCORE_VER_MAJOR(*expected_ver)) {
> + if (ADI_AXI_PCORE_VER_MAJOR(ver) !=
> + ADI_AXI_PCORE_VER_MAJOR(st->info->version)) {
> dev_err(&pdev->dev,
> "Major version mismatch. Expected %d.%.2d.%c, Reported %d.%.2d.%c\n",
> - ADI_AXI_PCORE_VER_MAJOR(*expected_ver),
> - ADI_AXI_PCORE_VER_MINOR(*expected_ver),
> - ADI_AXI_PCORE_VER_PATCH(*expected_ver),
> + ADI_AXI_PCORE_VER_MAJOR(st->info->version),
> + ADI_AXI_PCORE_VER_MINOR(st->info->version),
> + ADI_AXI_PCORE_VER_PATCH(st->info->version),
> ADI_AXI_PCORE_VER_MAJOR(ver),
> ADI_AXI_PCORE_VER_MINOR(ver),
> ADI_AXI_PCORE_VER_PATCH(ver));
> @@ -631,10 +879,18 @@ static int axi_dac_probe(struct platform_device *pdev)
> return 0;
> }
>
> -static unsigned int axi_dac_9_1_b_info = ADI_AXI_PCORE_VER(9, 1, 'b');
> +static const struct axi_dac_info dac_generic = {
> + .version = ADI_AXI_PCORE_VER(9, 1, 'b'),
> +};
> +
> +static const struct axi_dac_info dac_ad3552r = {
> + .version = ADI_AXI_PCORE_VER(9, 1, 'b'),
> + .bus_type = AXI_DAC_BUS_TYPE_DDR_QSPI,
> +};
>
> static const struct of_device_id axi_dac_of_match[] = {
> - { .compatible = "adi,axi-dac-9.1.b", .data = &axi_dac_9_1_b_info },
> + { .compatible = "adi,axi-dac-9.1.b", .data = &dac_generic },
> + { .compatible = "adi,axi-ad3552r", .data = &dac_ad3552r },
> {}
> };
> MODULE_DEVICE_TABLE(of, axi_dac_of_match);
>
