Re: [PATCH v2 04/13] i3c: master: Support ACPI enumeration of child devices

Frank Li
2026-04-10T02:17:34Z

On Thu, Apr 09, 2026 at 04:27:34PM +0530, Akhil R wrote:
> Although the existing subsystem allows host controllers to register
> through the ACPI table, it was not possible to describe I3C or I2C
> devices when using ACPI. This is because the driver relied on reg
> property to retrieve the PID, static address etc whereas ACPI uses
> _ADR or serial resources to describe such devices.
>
> Read _ADR and LVR from the ACPI resources and extract the data as per the
> ACPI specification for an I3C bus. Also read mipi-i3c-static-address as
> per the MIPI DISCO specifications [1] to get the static address to be
> used. Hence enable describing the I3C or I2C devices in the ACPI
> table, which is required if the device is using a static address or if it
> needs some specific properties to be attached to it.

Please wrap your commit message at 75 char.

>
> [1] https://www.mipi.org/mipi-disco-for-i3c-download
>
> Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
> ---
> drivers/i3c/master.c | 140 ++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 132 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
> index 5e0e926f61f3..08d0fcabd6f1 100644
> --- a/drivers/i3c/master.c
> +++ b/drivers/i3c/master.c
> @@ -5,6 +5,7 @@
> * Author: Boris Brezillon <boris.brezillon@bootlin.com>
> */
>
> +#include <linux/acpi.h>
> #include <linux/atomic.h>
> #include <linux/bug.h>
> #include <linux/device.h>
> @@ -2403,6 +2404,53 @@ EXPORT_SYMBOL_GPL(i3c_master_add_i3c_dev_locked);
>
> #define OF_I3C_REG1_IS_I2C_DEV BIT(31)
>
> +#ifdef CONFIG_ACPI
...

> +#ifdef CONFIG_ACPI
> +static int i3c_master_add_acpi_dev(struct i3c_master_controller *master,
> + struct fwnode_handle *fwnode)

Can you move this and below function to previous #ifdef CONFIG_ACPI block.

Frank