[PATCH v2 06/13] i3c: master: Add support for devices without PID

Akhil R
2026-04-09T11:01:27Z

Devices using SETAASA for address assignment are not required to have
a 48-bit PID according to the I3C specification. Allow such devices to
register and use the static address where PID was required.

Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
---
drivers/i3c/master.c | 51 ++++++++++++++++++++++++++++++++++----------
1 file changed, 40 insertions(+), 11 deletions(-)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index a0f7a0d35f3f..324a0440724e 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -1835,8 +1835,17 @@ i3c_master_register_new_i3c_devs(struct i3c_master_controller *master)
desc->dev->dev.type = &i3c_device_type;
desc->dev->dev.bus = &i3c_bus_type;
desc->dev->dev.release = i3c_device_release;
- dev_set_name(&desc->dev->dev, "%d-%llx", master->bus.id,
- desc->info.pid);
+
+ /*
+ * For devices without PID (e.g., SETAASA devices), use
+ * static address for naming instead.
+ */
+ if (desc->info.pid)
+ dev_set_name(&desc->dev->dev, "%d-%llx", master->bus.id,
+ desc->info.pid);
+ else
+ dev_set_name(&desc->dev->dev, "%d-%02x", master->bus.id,
+ desc->info.static_addr);

if (desc->boardinfo)
device_set_node(&desc->dev->dev, desc->boardinfo->fwnode);
@@ -2285,8 +2294,18 @@ static void i3c_master_attach_boardinfo(struct i3c_dev_desc *i3cdev)
struct i3c_dev_boardinfo *i3cboardinfo;

list_for_each_entry(i3cboardinfo, &master->boardinfo.i3c, node) {
- if (i3cdev->info.pid != i3cboardinfo->pid)
- continue;
+ /*
+ * For devices without PID (e.g., SETAASA devices), match by
+ * static address. For devices with PID, match by PID.
+ */
+ if (i3cboardinfo->pid) {
+ if (i3cdev->info.pid != i3cboardinfo->pid)
+ continue;
+ } else {
+ if (!i3cboardinfo->static_addr ||
+ i3cdev->info.static_addr != i3cboardinfo->static_addr)
+ continue;
+ }

i3cdev->boardinfo = i3cboardinfo;
i3cdev->info.static_addr = i3cboardinfo->static_addr;
@@ -2300,8 +2319,12 @@ i3c_master_search_i3c_dev_duplicate(struct i3c_dev_desc *refdev)
struct i3c_master_controller *master = i3c_dev_get_master(refdev);
struct i3c_dev_desc *i3cdev;

+ if (!refdev->info.pid)
+ return NULL;
+
i3c_bus_for_each_i3cdev(&master->bus, i3cdev) {
- if (i3cdev != refdev && i3cdev->info.pid == refdev->info.pid)
+ if (i3cdev != refdev && i3cdev->info.pid &&
+ i3cdev->info.pid == refdev->info.pid)
return i3cdev;
}

@@ -2601,9 +2624,15 @@ i3c_master_add_i3c_boardinfo(struct i3c_master_controller *master,

boardinfo->pid = ((u64)reg[1] << 32) | reg[2];

- if ((boardinfo->pid & GENMASK_ULL(63, 48)) ||
- I3C_PID_RND_LOWER_32BITS(boardinfo->pid))
- return -EINVAL;
+ /* For SETAASA devices, validate the static address instead of PID */
+ if (boardinfo->static_addr_method & I3C_ADDR_METHOD_SETAASA) {
+ if (!boardinfo->static_addr)
+ return -EINVAL;
+ } else {
+ if ((boardinfo->pid & GENMASK_ULL(63, 48)) ||
+ I3C_PID_RND_LOWER_32BITS(boardinfo->pid))
+ return -EINVAL;
+ }

boardinfo->init_dyn_addr = init_dyn_addr;
boardinfo->fwnode = fwnode_handle_get(fwnode);
@@ -2626,10 +2655,10 @@ static int i3c_master_add_of_dev(struct i3c_master_controller *master,
return ret;

/*
- * The manufacturer ID can't be 0. If reg[1] == 0 that means we're
- * dealing with an I2C device.
+ * I3C device should have either the manufacturer ID specified or the
+ * address discovery method specified. Else treat it as an I2C device.
*/
- if (!reg[1])
+ if (!reg[1] && !fwnode_property_present(fwnode, "mipi-i3c-static-method"))
ret = i3c_master_add_i2c_boardinfo(master, fwnode, reg);
else
ret = i3c_master_add_i3c_boardinfo(master, fwnode, reg);
--
2.50.1