Hi,
On Fri, Nov 08, 2024 at 01:03:20PM +0530, Shyam Sundar S K wrote:
> As of now, the I3C subsystem only has ARM-specific initialization, and
> there is no corresponding ACPI plumbing present. To address this, ACPI
> support needs to be added to both the I3C core and DW driver.
>
> Add support to get the ACPI handle from the _HID probed and parse the apci
> object to retrieve the slave information from BIOS.
>
> Based on the acpi object information propogated via BIOS, build the i3c
> board information so that the same information can be used across the
> driver to handle the slave requests.
>
> Co-developed-by: Sanket Goswami <Sanket.Goswami@xxxxxxx>
> Signed-off-by: Sanket Goswami <Sanket.Goswami@xxxxxxx>
> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@xxxxxxx>
> ---
> Cc: linux-acpi@xxxxxxxxxxxxxxx
>
> drivers/i3c/internals.h | 3 ++
> drivers/i3c/master.c | 84 ++++++++++++++++++++++++++++++
> drivers/i3c/master/dw-i3c-master.c | 7 +++
> include/linux/i3c/master.h | 1 +
> 4 files changed, 95 insertions(+)
>
> diff --git a/drivers/i3c/internals.h b/drivers/i3c/internals.h
> index 433f6088b7ce..178bc0ebe6b6 100644
> --- a/drivers/i3c/internals.h
> +++ b/drivers/i3c/internals.h
> @@ -10,6 +10,9 @@
>
> #include <linux/i3c/master.h>
>
> +#define I3C_GET_PID 0x08
> +#define I3C_GET_ADDR 0x7F
> +
> void i3c_bus_normaluse_lock(struct i3c_bus *bus);
> void i3c_bus_normaluse_unlock(struct i3c_bus *bus);
>
> diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
> index 6f3eb710a75d..0ceef2aa9161 100644
> --- a/drivers/i3c/master.c
> +++ b/drivers/i3c/master.c
> @@ -2251,6 +2251,84 @@ static int of_i3c_master_add_dev(struct i3c_master_controller *master,
> return ret;
> }
>
> +#if IS_ENABLED(CONFIG_ACPI)
> +static int i3c_acpi_configure_master(struct i3c_master_controller *master)
> +{
> + struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
> + enum i3c_addr_slot_status addrstatus;
> + struct i3c_dev_boardinfo *boardinfo;
> + struct device *dev = &master->dev;
> + struct fwnode_handle *fwnode;
> + struct acpi_device *adev;
> + u32 slv_addr, num_dev;
> + acpi_status status;
> + u64 val;
> +
> + status = acpi_evaluate_object_typed(master->ahandle, "_DSD", NULL, &buf, ACPI_TYPE_PACKAGE);
> + if (ACPI_FAILURE(status)) {
> + dev_err(&master->dev, "Error reading _DSD:%s\n", acpi_format_exception(status));
> + return -ENODEV;
> + }
Why do you need to do that?
> + num_dev = device_get_child_node_count(dev);
> + if (!num_dev) {
> + dev_err(&master->dev, "Error: no child node present\n");
> + return -EINVAL;
> + }
I think Jarkko already pointed out the problem with that. The whole
check should be dropped.
> + device_for_each_child_node(dev, fwnode) {
> + adev = to_acpi_device_node(fwnode);
> + if (!adev)
> + return -ENODEV;
> +
> + status = acpi_evaluate_integer(adev->handle, "_ADR", NULL, &val);
> + if (ACPI_FAILURE(status)) {
> + dev_err(&master->dev, "Error: eval _ADR failed\n");
> + return -EINVAL;
> + }
val = acpi_device_adr(adev);
> + slv_addr = val & I3C_GET_ADDR;
> +
> + boardinfo = devm_kzalloc(dev, sizeof(*boardinfo), GFP_KERNEL);
> + if (!boardinfo)
> + return -ENOMEM;
> +
> + if (slv_addr) {
> + if (slv_addr > I3C_MAX_ADDR)
> + return -EINVAL;
> +
> + addrstatus = i3c_bus_get_addr_slot_status(&master->bus, slv_addr);
> + if (addrstatus != I3C_ADDR_SLOT_FREE)
> + return -EINVAL;
> + }
> +
> + boardinfo->static_addr = slv_addr;
> + if (boardinfo->static_addr > I3C_MAX_ADDR)
> + return -EINVAL;
> +
> + addrstatus = i3c_bus_get_addr_slot_status(&master->bus, boardinfo->static_addr);
> + if (addrstatus != I3C_ADDR_SLOT_FREE)
> + return -EINVAL;
> +
> + boardinfo->pid = val >> I3C_GET_PID;
> + if ((boardinfo->pid & GENMASK_ULL(63, 48)) ||
> + I3C_PID_RND_LOWER_32BITS(boardinfo->pid))
> + return -EINVAL;
> +
> + /*
> + * According to the specification, SETDASA is not supported for DIMM slaves
> + * during device discovery. Therefore, BIOS will populate same initial
> + * dynamic address as the static address.
> + */
> + boardinfo->init_dyn_addr = boardinfo->static_addr;
> + list_add_tail(&boardinfo->node, &master->boardinfo.i3c);
> + }
> +
> + return 0;
> +}
> +#else
> +static int i3c_acpi_configure_master(struct i3c_master_controller *master) { return 0; }
> +#endif
I think this code should be placed into a separate file.
If the goal is to add ACPI support for code that is written for DT
only, then I think the first thing to do before that really should be
to convert the existing code to use the unified device property
interface, and move all the DT-only parts to a separate file(s).
thanks,
--
heikki
