From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx>
Reviewed-by: Rander Wang <rander.wang@xxxxxxxxx>
Signed-off-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
---
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,
+};
+
/**
* 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
