On 31-05-23, 11:37, Bard Liao wrote:
> From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
>
> This patch adds a new Device Number allocation strategy, with the IDA
> used only for devices that are wake-capable.
>
> "regular" devices such as amplifiers will use Device Numbers
> [1..min_ida-1].
>
> "wake-capable" devices such as jack or microphone codecs will use
> Device Numbers [min_ida..11].
>
> This hybrid strategy extends the number of supported devices in a
> system by only constraining the allocation if required, e.g. in the
> case of Intel LunarLake platforms the wake-capable devices are
> required to have a unique address to use the HDaudio SDI and HDAudio
> WAKEEN/WAKESTS registers.
This seems to be a consequence of Intel hardware decisions, so I guess
best suited place for this is Intel controller, do we really want to
have this in core logic?
>
> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
> Reviewed-by: Rander Wang <rander.wang@xxxxxxxxx>
> Signed-off-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
> ---
> drivers/soundwire/bus.c | 26 +++++++++++++++++++++-----
> include/linux/soundwire/sdw.h | 4 ++++
> 2 files changed, 25 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
> index e8c1c55a2a73..6f465cce8369 100644
> --- a/drivers/soundwire/bus.c
> +++ b/drivers/soundwire/bus.c
> @@ -159,7 +159,9 @@ static int sdw_delete_slave(struct device *dev, void *data)
>
> if (slave->dev_num) { /* clear dev_num if assigned */
> clear_bit(slave->dev_num, bus->assigned);
> - if (bus->dev_num_alloc == SDW_DEV_NUM_ALLOC_IDA)
> + if (bus->dev_num_alloc == SDW_DEV_NUM_ALLOC_IDA ||
> + (bus->dev_num_alloc == SDW_DEV_NUM_ALLOC_IDA_WAKE_ONLY &&
> + slave->prop.wake_capable))
> ida_free(&sdw_peripheral_ida, slave->dev_num);
> }
> list_del_init(&slave->node);
> @@ -699,17 +701,31 @@ EXPORT_SYMBOL(sdw_compare_devid);
> /* called with bus_lock held */
> static int sdw_get_device_num(struct sdw_slave *slave)
> {
> + struct sdw_bus *bus = slave->bus;
> int bit;
>
> - if (slave->bus->dev_num_alloc == SDW_DEV_NUM_ALLOC_IDA) {
> + if (bus->dev_num_alloc == SDW_DEV_NUM_ALLOC_IDA ||
> + (bus->dev_num_alloc == SDW_DEV_NUM_ALLOC_IDA_WAKE_ONLY &&
> + slave->prop.wake_capable)) {
> bit = ida_alloc_range(&sdw_peripheral_ida,
> - slave->bus->dev_num_ida_min, SDW_MAX_DEVICES,
> + bus->dev_num_ida_min, SDW_MAX_DEVICES,
> GFP_KERNEL);
> if (bit < 0)
> goto err;
> } else {
> - bit = find_first_zero_bit(slave->bus->assigned, SDW_MAX_DEVICES);
> - if (bit == SDW_MAX_DEVICES) {
> + int max_devices = SDW_MAX_DEVICES;
> +
> + if (bus->dev_num_alloc == SDW_DEV_NUM_ALLOC_IDA_WAKE_ONLY &&
> + !slave->prop.wake_capable) {
> + max_devices = bus->dev_num_ida_min - 1;
> +
> + /* range check */
> + if (max_devices < 1 || max_devices > SDW_MAX_DEVICES)
> + return -EINVAL;
> + }
> +
> + bit = find_first_zero_bit(bus->assigned, max_devices);
> + if (bit == max_devices) {
> bit = -ENODEV;
> goto err;
> }
> diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h
> index 4656d6d0f3bb..8a7541ac735e 100644
> --- a/include/linux/soundwire/sdw.h
> +++ b/include/linux/soundwire/sdw.h
> @@ -869,10 +869,14 @@ struct sdw_master_ops {
> * @SDW_DEV_NUM_ALLOC_DEFAULT: unconstrained first-come-first-serve allocation,
> * using range [1, 11]
> * @SDW_DEV_NUM_ALLOC_IDA: IDA-based allocation, using range [ida_min, 11]
> + * @SDW_DEV_NUM_ALLOC_IDA_WAKE_ONLY: Hybrid allocation where wake-capable devices rely on
> + * IDA-based allocation and range [ida_min, 11], while regular devices rely on default
> + * allocation in range [1, ida_min - 1]
> */
> enum sdw_dev_num_alloc {
> SDW_DEV_NUM_ALLOC_DEFAULT = 0,
> SDW_DEV_NUM_ALLOC_IDA,
> + SDW_DEV_NUM_ALLOC_IDA_WAKE_ONLY,
> };
>
> /**
> --
> 2.25.1
--
~Vinod
