It is used by sound/soc/sof/intel/hda.c. Please check history of alsa-devel mail list. Bard Liao is working on it.
> -----Original Message-----
> From: Alsa-devel <alsa-devel-bounces@xxxxxxxxxxxxxxxx> On Behalf Of Sudip
> Mukherjee
> Sent: Sunday, April 26, 2020 7:55 AM
> To: Vinod Koul <vkoul@xxxxxxxxxx>; Kale, Sanyog R <sanyog.r.kale@xxxxxxxxx>;
> Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
> Cc: alsa-devel@xxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Sudip
> Mukherjee <sudipm.mukherjee@xxxxxxxxx>
> Subject: [PATCH v2] soundwire: intel: Remove unused function
>
> The function sdw_intel_init() is not used anywhere, remove it for now.
> And that makes sdw_intel_add_controller(), sdw_intel_acpi_cb() and link_mask
> unused, so remove them as well.
>
> Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
> ---
> drivers/soundwire/intel_init.c | 162 -----------------------------------------
> 1 file changed, 162 deletions(-)
>
> diff --git a/drivers/soundwire/intel_init.c b/drivers/soundwire/intel_init.c index
> ad7053463889..d90929a5043b 100644
> --- a/drivers/soundwire/intel_init.c
> +++ b/drivers/soundwire/intel_init.c
> @@ -23,10 +23,6 @@
> #define SDW_LINK_BASE 0x30000
> #define SDW_LINK_SIZE 0x10000
>
> -static int link_mask;
> -module_param_named(sdw_link_mask, link_mask, int, 0444); -
> MODULE_PARM_DESC(sdw_link_mask, "Intel link mask (one bit per link)");
> -
> static int sdw_intel_cleanup_pdev(struct sdw_intel_ctx *ctx) {
> struct sdw_intel_link_res *link = ctx->links; @@ -47,164 +43,6 @@
> static int sdw_intel_cleanup_pdev(struct sdw_intel_ctx *ctx)
> return 0;
> }
>
> -static struct sdw_intel_ctx
> -*sdw_intel_add_controller(struct sdw_intel_res *res) -{
> - struct platform_device_info pdevinfo;
> - struct platform_device *pdev;
> - struct sdw_intel_link_res *link;
> - struct sdw_intel_ctx *ctx;
> - struct acpi_device *adev;
> - int ret, i;
> - u8 count;
> - u32 caps;
> -
> - if (acpi_bus_get_device(res->handle, &adev))
> - return NULL;
> -
> - /* Found controller, find links supported */
> - count = 0;
> - ret = fwnode_property_read_u8_array(acpi_fwnode_handle(adev),
> - "mipi-sdw-master-count", &count,
> 1);
> -
> - /* Don't fail on error, continue and use hw value */
> - if (ret) {
> - dev_err(&adev->dev,
> - "Failed to read mipi-sdw-master-count: %d\n", ret);
> - count = SDW_MAX_LINKS;
> - }
> -
> - /* Check SNDWLCAP.LCOUNT */
> - caps = ioread32(res->mmio_base + SDW_SHIM_BASE +
> SDW_SHIM_LCAP);
> - caps &= GENMASK(2, 0);
> -
> - /* Check HW supported vs property value and use min of two */
> - count = min_t(u8, caps, count);
> -
> - /* Check count is within bounds */
> - if (count > SDW_MAX_LINKS) {
> - dev_err(&adev->dev, "Link count %d exceeds max %d\n",
> - count, SDW_MAX_LINKS);
> - return NULL;
> - } else if (!count) {
> - dev_warn(&adev->dev, "No SoundWire links detected\n");
> - return NULL;
> - }
> -
> - dev_dbg(&adev->dev, "Creating %d SDW Link devices\n", count);
> -
> - ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
> - if (!ctx)
> - return NULL;
> -
> - ctx->count = count;
> - ctx->links = kcalloc(ctx->count, sizeof(*ctx->links), GFP_KERNEL);
> - if (!ctx->links)
> - goto link_err;
> -
> - link = ctx->links;
> -
> - /* Create SDW Master devices */
> - for (i = 0; i < count; i++) {
> - if (link_mask && !(link_mask & BIT(i))) {
> - dev_dbg(&adev->dev,
> - "Link %d masked, will not be enabled\n", i);
> - link++;
> - continue;
> - }
> -
> - link->registers = res->mmio_base + SDW_LINK_BASE
> - + (SDW_LINK_SIZE * i);
> - link->shim = res->mmio_base + SDW_SHIM_BASE;
> - link->alh = res->mmio_base + SDW_ALH_BASE;
> -
> - link->ops = res->ops;
> - link->dev = res->dev;
> -
> - memset(&pdevinfo, 0, sizeof(pdevinfo));
> -
> - pdevinfo.parent = res->parent;
> - pdevinfo.name = "int-sdw";
> - pdevinfo.id = i;
> - pdevinfo.fwnode = acpi_fwnode_handle(adev);
> -
> - pdev = platform_device_register_full(&pdevinfo);
> - if (IS_ERR(pdev)) {
> - dev_err(&adev->dev,
> - "platform device creation failed: %ld\n",
> - PTR_ERR(pdev));
> - goto pdev_err;
> - }
> -
> - link->pdev = pdev;
> - link++;
> - }
> -
> - return ctx;
> -
> -pdev_err:
> - sdw_intel_cleanup_pdev(ctx);
> -link_err:
> - kfree(ctx);
> - return NULL;
> -}
> -
> -static acpi_status sdw_intel_acpi_cb(acpi_handle handle, u32 level,
> - void *cdata, void **return_value)
> -{
> - struct sdw_intel_res *res = cdata;
> - struct acpi_device *adev;
> - acpi_status status;
> - u64 adr;
> -
> - status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL,
> &adr);
> - if (ACPI_FAILURE(status))
> - return AE_OK; /* keep going */
> -
> - if (acpi_bus_get_device(handle, &adev)) {
> - pr_err("%s: Couldn't find ACPI handle\n", __func__);
> - return AE_NOT_FOUND;
> - }
> -
> - res->handle = handle;
> -
> - /*
> - * On some Intel platforms, multiple children of the HDAS
> - * device can be found, but only one of them is the SoundWire
> - * controller. The SNDW device is always exposed with
> - * Name(_ADR, 0x40000000), with bits 31..28 representing the
> - * SoundWire link so filter accordingly
> - */
> - if ((adr & GENMASK(31, 28)) >> 28 != SDW_LINK_TYPE)
> - return AE_OK; /* keep going */
> -
> - /* device found, stop namespace walk */
> - return AE_CTRL_TERMINATE;
> -}
> -
> -/**
> - * sdw_intel_init() - SoundWire Intel init routine
> - * @parent_handle: ACPI parent handle
> - * @res: resource data
> - *
> - * This scans the namespace and creates SoundWire link controller devices
> - * based on the info queried.
> - */
> -static void *sdw_intel_init(acpi_handle *parent_handle,
> - struct sdw_intel_res *res)
> -{
> - acpi_status status;
> -
> - status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
> - parent_handle, 1,
> - sdw_intel_acpi_cb,
> - NULL, res, NULL);
> - if (ACPI_FAILURE(status))
> - return NULL;
> -
> - return sdw_intel_add_controller(res);
> -}
> -
> /**
> * sdw_intel_exit() - SoundWire Intel exit
> * @arg: callback context
> --
> 2.11.0
