On Wed, Jul 12, 2023 at 11:10:48AM +0200, Cezary Rojewski wrote:
> With iteration helpers added there is a room for more complex query
> tasks which are commonly performed by sound drivers. Implement them in
> common API so that a unified mechanism is available for all of them.
>
> While the acpi_nhlt_endpoint_dmic_count() stands out a bit, it is a
> critical component for any AudioDSP driver to know how many digital
> microphones it is dealing with. There is no one perfect method, but the
> best one available is provided.
...
> +bool acpi_nhlt_endpoint_match(const struct acpi_nhlt_endpoint *ep,
> + int link_type, int dev_type, int dir, int bus_id)
> +{
> + return ep &&
> + (link_type < 0 || ep->link_type == link_type) &&
> + (dev_type < 0 || ep->device_type == dev_type) &&
> + (dir < 0 || ep->direction == dir) &&
> + (bus_id < 0 || ep->virtual_bus_id == bus_id);
I think you can split these for better reading.
if (!ep)
return false;
if (link_type >= 0 && ep->link_type != link_type)
return false;
if (dev_type >= 0 && ep->device_type != dev_type)
return false;
if (dir >= 0 && ep->direction != dir)
return false;
if (bus_id >= 0 && ep->virtual_bus_id != bus_id)
return false;
return true;
Yes, much more lines, but readability is better in my opinion.
I also believe that code generation on x86_64 will be the same.
> +}
...
> +struct acpi_nhlt_endpoint *
> +acpi_nhlt_find_endpoint(const struct acpi_table_nhlt *tb,
> + int link_type, int dev_type, int dir, int bus_id)
> +{
> + struct acpi_nhlt_endpoint *ep;
> + if (!tb)
> + return ERR_PTR(-EINVAL);
Just wondering how often we will have a caller that supplies NULL for tb.
> + for_each_nhlt_endpoint(tb, ep)
> + if (acpi_nhlt_endpoint_match(ep, link_type, dev_type, dir, bus_id))
> + return ep;
> + return NULL;
> +}
...
> +struct acpi_nhlt_format_config *
> +acpi_nhlt_endpoint_find_fmtcfg(const struct acpi_nhlt_endpoint *ep,
> + u16 ch, u32 rate, u16 vbps, u16 bps)
> +{
> + struct acpi_nhlt_wave_extensible *wav;
> + struct acpi_nhlt_format_config *fmt;
> + if (!ep)
> + return ERR_PTR(-EINVAL);
Similar Q as above.
> + for_each_nhlt_endpoint_fmtcfg(ep, fmt) {
> + wav = &fmt->format;
> +
> + if (wav->channel_count == ch &&
> + wav->valid_bits_per_sample == vbps &&
> + wav->bits_per_sample == bps &&
> + wav->samples_per_sec == rate)
Also can be split, but this one readable in the original form.
> + return fmt;
> + }
> +
> + return NULL;
> +}
...
> +struct acpi_nhlt_format_config *
> +acpi_nhlt_find_fmtcfg(const struct acpi_table_nhlt *tb,
> + int link_type, int dev_type, int dir, int bus_id,
> + u16 ch, u32 rate, u16 vbps, u16 bps)
> +{
> + struct acpi_nhlt_format_config *fmt;
> + struct acpi_nhlt_endpoint *ep;
> + if (!tb)
> + return ERR_PTR(-EINVAL);
Same as above.
Looking at them, wouldn't simply returning NULL suffice?
> + for_each_nhlt_endpoint(tb, ep) {
> + if (!acpi_nhlt_endpoint_match(ep, link_type, dev_type, dir, bus_id))
> + continue;
> +
> + fmt = acpi_nhlt_endpoint_find_fmtcfg(ep, ch, rate, vbps, bps);
> + if (fmt)
> + return fmt;
> + }
> +
> + return NULL;
> +}
...
> +int acpi_nhlt_endpoint_dmic_count(const struct acpi_nhlt_endpoint *ep)
> +{
> + struct acpi_nhlt_vendor_mic_devcfg *vendor_cfg;
> + struct acpi_nhlt_format_config *fmt;
> + struct acpi_nhlt_mic_devcfg *devcfg;
> + u16 max_ch = 0;
> +
> + if (!ep || ep->link_type != ACPI_NHLT_PDM)
> + return -EINVAL;
> +
> + /* Find max number of channels based on formats configuration. */
> + for_each_nhlt_endpoint_fmtcfg(ep, fmt)
> + max_ch = max(fmt->format.channel_count, max_ch);
> +
> + /* If @ep not a mic array, fallback to channels count. */
> + devcfg = acpi_nhlt_endpoint_mic_devcfg(ep);
> + if (!devcfg || devcfg->config_type != ACPI_NHLT_CONFIG_TYPE_MIC_ARRAY)
> + return max_ch;
> +
> + switch (devcfg->array_type) {
> + case ACPI_NHLT_SMALL_LINEAR_2ELEMENT:
> + case ACPI_NHLT_BIG_LINEAR_2ELEMENT:
> + return 2;
> +
> + case ACPI_NHLT_FIRST_GEOMETRY_LINEAR_4ELEMENT:
> + case ACPI_NHLT_PLANAR_LSHAPED_4ELEMENT:
> + case ACPI_NHLT_SECOND_GEOMETRY_LINEAR_4ELEMENT:
> + return 4;
> +
> + case ACPI_NHLT_VENDOR_DEFINED:
> + vendor_cfg = acpi_nhlt_endpoint_vendor_mic_devcfg(ep);
> + if (!vendor_cfg)
> + return -EINVAL;
> + return vendor_cfg->num_mics;
> +
> + default:
> + pr_warn("undefined mic array type: %#x\n", devcfg->array_type);
Is this function can ever be called without backing device? If not,
I would supply (ACPI?) device pointer and use dev_warn() instead.
But I'm not sure about this. Up to you, folks.
> + return max_ch;
> + }
> +}
--
With Best Regards,
Andy Shevchenko
