diff options
| author | Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> | 2022-08-23 12:50:03 +0800 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2022-08-30 10:16:41 +0530 |
| commit | c60561014257699d81ab392eb6cb6389ad8907df (patch) | |
| tree | 477c21fb7f9ce71f7a81d7020aea5a6b50cd3501 /drivers | |
| parent | 88de0a8f48bc2339e8c279315320e6f406ff5f96 (diff) | |
soundwire: bus: allow device number to be unique at system level
The SoundWire specification allows the device number to be allocated
at will. When a system includes multiple SoundWire links, the device
number scope is limited to the link to which the device is attached.
However, for integration/debug it can be convenient to have a unique
device number across the system. This patch adds a 'dev_num_ida_min'
field at the bus level, which when set will be used to allocate an
IDA.
The allocation happens when a hardware device reports as ATTACHED. If
any error happens during the enumeration, the allocated IDA is not
freed - the device number will be reused if/when the device re-joins
the bus. The IDA is only freed when the Linux device is unregistered.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20220823045004.2670658-3-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/soundwire/bus.c | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 1823a7414d04..d773eee71bc1 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -12,6 +12,7 @@ #include "sysfs_local.h" static DEFINE_IDA(sdw_bus_ida); +static DEFINE_IDA(sdw_peripheral_ida); static int sdw_get_id(struct sdw_bus *bus) { @@ -156,9 +157,11 @@ static int sdw_delete_slave(struct device *dev, void *data) mutex_lock(&bus->bus_lock); - if (slave->dev_num) /* clear dev_num if assigned */ + if (slave->dev_num) { /* clear dev_num if assigned */ clear_bit(slave->dev_num, bus->assigned); - + if (bus->dev_num_ida_min) + ida_free(&sdw_peripheral_ida, slave->dev_num); + } list_del_init(&slave->node); mutex_unlock(&bus->bus_lock); @@ -638,10 +641,18 @@ static int sdw_get_device_num(struct sdw_slave *slave) { int bit; - bit = find_first_zero_bit(slave->bus->assigned, SDW_MAX_DEVICES); - if (bit == SDW_MAX_DEVICES) { - bit = -ENODEV; - goto err; + if (slave->bus->dev_num_ida_min) { + bit = ida_alloc_range(&sdw_peripheral_ida, + slave->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) { + bit = -ENODEV; + goto err; + } } /* |