1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2 // Copyright(c) 2015-17 Intel Corporation.
5 * SDW Intel Init Routines
7 * Initializes and creates SDW devices based on ACPI and Hardware values
10 #include <linux/acpi.h>
11 #include <linux/export.h>
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/soundwire/sdw_intel.h>
18 #define SDW_LINK_TYPE 4 /* from Intel ACPI documentation */
19 #define SDW_MAX_LINKS 4
20 #define SDW_SHIM_LCAP 0x0
21 #define SDW_SHIM_BASE 0x2C000
22 #define SDW_ALH_BASE 0x2C800
23 #define SDW_LINK_BASE 0x30000
24 #define SDW_LINK_SIZE 0x10000
27 module_param_named(sdw_link_mask, link_mask, int, 0444);
28 MODULE_PARM_DESC(sdw_link_mask, "Intel link mask (one bit per link)");
30 static int sdw_intel_cleanup_pdev(struct sdw_intel_ctx *ctx)
32 struct sdw_intel_link_res *link = ctx->links;
38 for (i = 0; i < ctx->count; i++) {
40 platform_device_unregister(link->pdev);
50 static struct sdw_intel_ctx
51 *sdw_intel_add_controller(struct sdw_intel_res *res)
53 struct platform_device_info pdevinfo;
54 struct platform_device *pdev;
55 struct sdw_intel_link_res *link;
56 struct sdw_intel_ctx *ctx;
57 struct acpi_device *adev;
62 if (acpi_bus_get_device(res->handle, &adev))
65 /* Found controller, find links supported */
67 ret = fwnode_property_read_u8_array(acpi_fwnode_handle(adev),
68 "mipi-sdw-master-count", &count, 1);
70 /* Don't fail on error, continue and use hw value */
73 "Failed to read mipi-sdw-master-count: %d\n", ret);
74 count = SDW_MAX_LINKS;
77 /* Check SNDWLCAP.LCOUNT */
78 caps = ioread32(res->mmio_base + SDW_SHIM_BASE + SDW_SHIM_LCAP);
79 caps &= GENMASK(2, 0);
81 /* Check HW supported vs property value and use min of two */
82 count = min_t(u8, caps, count);
84 /* Check count is within bounds */
85 if (count > SDW_MAX_LINKS) {
86 dev_err(&adev->dev, "Link count %d exceeds max %d\n",
87 count, SDW_MAX_LINKS);
92 dev_warn(&adev->dev, "No SoundWire links detected\n");
96 dev_dbg(&adev->dev, "Creating %d SDW Link devices\n", count);
98 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
103 ctx->links = kcalloc(ctx->count, sizeof(*ctx->links), GFP_KERNEL);
109 /* Create SDW Master devices */
110 for (i = 0; i < count; i++) {
111 if (link_mask && !(link_mask & BIT(i))) {
113 "Link %d masked, will not be enabled\n", i);
118 link->registers = res->mmio_base + SDW_LINK_BASE
119 + (SDW_LINK_SIZE * i);
120 link->shim = res->mmio_base + SDW_SHIM_BASE;
121 link->alh = res->mmio_base + SDW_ALH_BASE;
123 link->ops = res->ops;
124 link->dev = res->dev;
126 memset(&pdevinfo, 0, sizeof(pdevinfo));
128 pdevinfo.parent = res->parent;
129 pdevinfo.name = "int-sdw";
131 pdevinfo.fwnode = acpi_fwnode_handle(adev);
133 pdev = platform_device_register_full(&pdevinfo);
136 "platform device creation failed: %ld\n",
148 sdw_intel_cleanup_pdev(ctx);
154 static acpi_status sdw_intel_acpi_cb(acpi_handle handle, u32 level,
155 void *cdata, void **return_value)
157 struct sdw_intel_res *res = cdata;
158 struct acpi_device *adev;
162 status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &adr);
163 if (ACPI_FAILURE(status))
164 return AE_OK; /* keep going */
166 if (acpi_bus_get_device(handle, &adev)) {
167 pr_err("%s: Couldn't find ACPI handle\n", __func__);
171 res->handle = handle;
174 * On some Intel platforms, multiple children of the HDAS
175 * device can be found, but only one of them is the SoundWire
176 * controller. The SNDW device is always exposed with
177 * Name(_ADR, 0x40000000), with bits 31..28 representing the
178 * SoundWire link so filter accordingly
180 if ((adr & GENMASK(31, 28)) >> 28 != SDW_LINK_TYPE)
181 return AE_OK; /* keep going */
183 /* device found, stop namespace walk */
184 return AE_CTRL_TERMINATE;
188 * sdw_intel_init() - SoundWire Intel init routine
189 * @parent_handle: ACPI parent handle
190 * @res: resource data
192 * This scans the namespace and creates SoundWire link controller devices
193 * based on the info queried.
195 void *sdw_intel_init(acpi_handle *parent_handle, struct sdw_intel_res *res)
199 status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
203 if (ACPI_FAILURE(status))
206 return sdw_intel_add_controller(res);
210 * sdw_intel_exit() - SoundWire Intel exit
211 * @arg: callback context
213 * Delete the controller instances created and cleanup
215 void sdw_intel_exit(struct sdw_intel_ctx *ctx)
217 sdw_intel_cleanup_pdev(ctx);
220 EXPORT_SYMBOL(sdw_intel_exit);
222 MODULE_LICENSE("Dual BSD/GPL");
223 MODULE_DESCRIPTION("Intel Soundwire Init Library");