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![Rafael J. Wysocki](/assets/img/avatar_default.png)
Replace acpi_bus_get_device() that is going to be dropped with acpi_fetch_acpi_dev(). No intentional functional impact. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/2828205.e9J7NaK4W3@kreacher Signed-off-by: Takashi Iwai <tiwai@suse.de>
185 lines
4.7 KiB
C
185 lines
4.7 KiB
C
// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
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// Copyright(c) 2015-2021 Intel Corporation.
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/*
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* SDW Intel ACPI scan helpers
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*/
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#include <linux/acpi.h>
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#include <linux/bits.h>
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#include <linux/bitfield.h>
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#include <linux/device.h>
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#include <linux/errno.h>
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#include <linux/export.h>
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#include <linux/fwnode.h>
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#include <linux/module.h>
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#include <linux/soundwire/sdw_intel.h>
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#include <linux/string.h>
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#define SDW_LINK_TYPE 4 /* from Intel ACPI documentation */
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#define SDW_MAX_LINKS 4
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static int ctrl_link_mask;
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module_param_named(sdw_link_mask, ctrl_link_mask, int, 0444);
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MODULE_PARM_DESC(sdw_link_mask, "Intel link mask (one bit per link)");
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static bool is_link_enabled(struct fwnode_handle *fw_node, int i)
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{
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struct fwnode_handle *link;
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char name[32];
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u32 quirk_mask = 0;
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/* Find master handle */
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snprintf(name, sizeof(name),
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"mipi-sdw-link-%d-subproperties", i);
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link = fwnode_get_named_child_node(fw_node, name);
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if (!link)
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return false;
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fwnode_property_read_u32(link,
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"intel-quirk-mask",
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&quirk_mask);
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if (quirk_mask & SDW_INTEL_QUIRK_MASK_BUS_DISABLE)
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return false;
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return true;
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}
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static int
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sdw_intel_scan_controller(struct sdw_intel_acpi_info *info)
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{
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struct acpi_device *adev = acpi_fetch_acpi_dev(info->handle);
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int ret, i;
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u8 count;
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if (!adev)
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return -EINVAL;
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/* Found controller, find links supported */
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count = 0;
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ret = fwnode_property_read_u8_array(acpi_fwnode_handle(adev),
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"mipi-sdw-master-count", &count, 1);
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/*
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* In theory we could check the number of links supported in
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* hardware, but in that step we cannot assume SoundWire IP is
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* powered.
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*
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* In addition, if the BIOS doesn't even provide this
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* 'master-count' property then all the inits based on link
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* masks will fail as well.
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*
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* We will check the hardware capabilities in the startup() step
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*/
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if (ret) {
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dev_err(&adev->dev,
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"Failed to read mipi-sdw-master-count: %d\n", ret);
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return -EINVAL;
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}
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/* Check count is within bounds */
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if (count > SDW_MAX_LINKS) {
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dev_err(&adev->dev, "Link count %d exceeds max %d\n",
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count, SDW_MAX_LINKS);
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return -EINVAL;
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}
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if (!count) {
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dev_warn(&adev->dev, "No SoundWire links detected\n");
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return -EINVAL;
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}
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dev_dbg(&adev->dev, "ACPI reports %d SDW Link devices\n", count);
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info->count = count;
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info->link_mask = 0;
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for (i = 0; i < count; i++) {
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if (ctrl_link_mask && !(ctrl_link_mask & BIT(i))) {
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dev_dbg(&adev->dev,
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"Link %d masked, will not be enabled\n", i);
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continue;
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}
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if (!is_link_enabled(acpi_fwnode_handle(adev), i)) {
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dev_dbg(&adev->dev,
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"Link %d not selected in firmware\n", i);
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continue;
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}
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info->link_mask |= BIT(i);
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}
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return 0;
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}
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static acpi_status sdw_intel_acpi_cb(acpi_handle handle, u32 level,
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void *cdata, void **return_value)
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{
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struct sdw_intel_acpi_info *info = cdata;
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acpi_status status;
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u64 adr;
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status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &adr);
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if (ACPI_FAILURE(status))
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return AE_OK; /* keep going */
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if (!acpi_fetch_acpi_dev(handle)) {
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pr_err("%s: Couldn't find ACPI handle\n", __func__);
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return AE_NOT_FOUND;
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}
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/*
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* On some Intel platforms, multiple children of the HDAS
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* device can be found, but only one of them is the SoundWire
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* controller. The SNDW device is always exposed with
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* Name(_ADR, 0x40000000), with bits 31..28 representing the
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* SoundWire link so filter accordingly
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*/
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if (FIELD_GET(GENMASK(31, 28), adr) != SDW_LINK_TYPE)
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return AE_OK; /* keep going */
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/* found the correct SoundWire controller */
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info->handle = handle;
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/* device found, stop namespace walk */
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return AE_CTRL_TERMINATE;
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}
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/**
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* sdw_intel_acpi_scan() - SoundWire Intel init routine
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* @parent_handle: ACPI parent handle
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* @info: description of what firmware/DSDT tables expose
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*
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* This scans the namespace and queries firmware to figure out which
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* links to enable. A follow-up use of sdw_intel_probe() and
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* sdw_intel_startup() is required for creation of devices and bus
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* startup
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*/
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int sdw_intel_acpi_scan(acpi_handle *parent_handle,
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struct sdw_intel_acpi_info *info)
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{
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acpi_status status;
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info->handle = NULL;
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/*
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* In the HDAS ACPI scope, 'SNDW' may be either the child of
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* 'HDAS' or the grandchild of 'HDAS'. So let's go through
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* the ACPI from 'HDAS' at max depth of 2 to find the 'SNDW'
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* device.
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*/
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status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
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parent_handle, 2,
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sdw_intel_acpi_cb,
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NULL, info, NULL);
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if (ACPI_FAILURE(status) || info->handle == NULL)
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return -ENODEV;
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return sdw_intel_scan_controller(info);
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}
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EXPORT_SYMBOL_NS(sdw_intel_acpi_scan, SND_INTEL_SOUNDWIRE_ACPI);
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MODULE_LICENSE("Dual BSD/GPL");
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MODULE_DESCRIPTION("Intel Soundwire ACPI helpers");
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