Re: [PATCH 1/4] soundwire: add enum to control device number allocation

On 31-05-23, 11:37, Bard Liao wrote:

From: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com

Commit c60561014257 ("soundwire: bus: allow device number to be unique at system level") introduced two strategies to allocate device numbers.

a) a default unconstrained allocation, where each bus can allocate Device Numbers independently.

b) an ida-based allocation. In this case each Device Number will be unique at the system-level.

The IDA-based allocation is useful to simplify debug, but it was also introduced as a prerequisite to deal with the Intel Lunar Lake hardware programming sequences: the wake-ups have to be handled with a system-unique SDI address at the HDaudio controller level.

At the time, the restriction introduced by the IDA to 8 devices total seemed perfectly fine, but recently hardware vendors created configurations with more than 8 devices.

This patch provides an iso-functionality change, with the allocation selected with an enum instead of an 'ida_min' value. Follow-up patches will add a new allocation strategy to allow for more than 8 devices using information on the type of devices, and only use the IDA-based allocation for devices capable of generating a wake.

Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com Reviewed-by: Rander Wang rander.wang@intel.com Signed-off-by: Bard Liao yung-chuan.liao@linux.intel.com

---

drivers/soundwire/bus.c | 4 ++-- drivers/soundwire/intel_auxdevice.c | 1 + include/linux/soundwire/sdw.h | 16 +++++++++++++++- 3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index b44f8d0affa6..e8c1c55a2a73 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -159,7 +159,7 @@ 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_ida_min)
  

• if (bus->dev_num_alloc == SDW_DEV_NUM_ALLOC_IDA)
  ida_free(&sdw_peripheral_ida, slave->dev_num);
  

  } list_del_init(&slave->node);

@@ -701,7 +701,7 @@ static int sdw_get_device_num(struct sdw_slave *slave) { int bit;

• if (slave->bus->dev_num_ida_min) {

• if (slave->bus->dev_num_alloc == SDW_DEV_NUM_ALLOC_IDA) { bit = ida_alloc_range(&sdw_peripheral_ida, slave->bus->dev_num_ida_min, SDW_MAX_DEVICES, GFP_KERNEL);

diff --git a/drivers/soundwire/intel_auxdevice.c b/drivers/soundwire/intel_auxdevice.c index 0daa6ca9a224..30f3d2ab80fd 100644 --- a/drivers/soundwire/intel_auxdevice.c +++ b/drivers/soundwire/intel_auxdevice.c @@ -165,6 +165,7 @@ static int intel_link_probe(struct auxiliary_device *auxdev, cdns->msg_count = 0;

bus->link_id = auxdev->id;

• bus->dev_num_alloc = SDW_DEV_NUM_ALLOC_IDA; bus->dev_num_ida_min = INTEL_DEV_NUM_IDA_MIN; bus->clk_stop_timeout = 1;

diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h index c076a3f879b3..4656d6d0f3bb 100644 --- a/include/linux/soundwire/sdw.h +++ b/include/linux/soundwire/sdw.h @@ -864,6 +864,17 @@ struct sdw_master_ops { void (*new_peripheral_assigned)(struct sdw_bus *bus, int dev_num); };

+/**

• • enum sdw_dev_num_alloc - Device Number allocation strategies
• • @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]
• */

+enum sdw_dev_num_alloc {

• SDW_DEV_NUM_ALLOC_DEFAULT = 0,
• SDW_DEV_NUM_ALLOC_IDA,

Let default be IDA as 0, am sure we are not setting this field in qcom or amd controller, lets retain the defaults please

+};

/**

• struct sdw_bus - SoundWire bus
• @dev: Shortcut to &bus->md->dev to avoid changing the entire code.

@@ -895,9 +906,11 @@ struct sdw_master_ops {

• meaningful if multi_link is set. If set to 1, hardware-based
• synchronization will be used even if a stream only uses a single
• SoundWire segment.

• • @dev_num_alloc: bus-specific device number allocation
  • @dev_num_ida_min: if set, defines the minimum values for the IDA
  • used to allocate system-unique device numbers. This value needs to be

• • identical across all SoundWire bus in the system.

• • identical across all SoundWire bus in the system. Only used if @sdw_num_alloc
• • is not default.
  */

struct sdw_bus { struct device *dev; @@ -922,6 +935,7 @@ struct sdw_bus { u32 bank_switch_timeout; bool multi_link; int hw_sync_min_links;

• enum sdw_dev_num_alloc dev_num_alloc; int dev_num_ida_min;

};

-- 2.25.1