swh:1:snp:c2847dfd741eae21606027cf29250d1ebcd63fb4
Tip revision: 2ef96a5bb12be62ef75b5828c0aab838ebb29cb8 authored by Linus Torvalds on 10 May 2020, 22:16:58 UTC
Linux 5.7-rc5
Linux 5.7-rc5
Tip revision: 2ef96a5
intel_init.c
// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
// Copyright(c) 2015-17 Intel Corporation.
/*
* SDW Intel Init Routines
*
* Initializes and creates SDW devices based on ACPI and Hardware values
*/
#include <linux/acpi.h>
#include <linux/export.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/soundwire/sdw_intel.h>
#include "intel.h"
#define SDW_LINK_TYPE 4 /* from Intel ACPI documentation */
#define SDW_MAX_LINKS 4
#define SDW_SHIM_LCAP 0x0
#define SDW_SHIM_BASE 0x2C000
#define SDW_ALH_BASE 0x2C800
#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;
int i;
if (!link)
return 0;
for (i = 0; i < ctx->count; i++) {
if (link->pdev)
platform_device_unregister(link->pdev);
link++;
}
kfree(ctx->links);
ctx->links = NULL;
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.
*/
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
*
* Delete the controller instances created and cleanup
*/
void sdw_intel_exit(struct sdw_intel_ctx *ctx)
{
sdw_intel_cleanup_pdev(ctx);
kfree(ctx);
}
EXPORT_SYMBOL(sdw_intel_exit);
MODULE_LICENSE("Dual BSD/GPL");
MODULE_DESCRIPTION("Intel Soundwire Init Library");