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

[Frank Li]

On Thu, Apr 09, 2026 at 04:27:36PM +0530, Akhil R wrote:
> 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@xxxxxxxxxx>
> ---

Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
>  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
>