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);
90 dev_warn(&adev->dev, "No SoundWire links detected\n");
94 dev_dbg(&adev->dev, "Creating %d SDW Link devices\n", count);
96 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
101 ctx->links = kcalloc(ctx->count, sizeof(*ctx->links), GFP_KERNEL);
107 /* Create SDW Master devices */
108 for (i = 0; i < count; i++) {
109 if (link_mask && !(link_mask & BIT(i))) {
111 "Link %d masked, will not be enabled\n", i);
116 link->registers = res->mmio_base + SDW_LINK_BASE
117 + (SDW_LINK_SIZE * i);
118 link->shim = res->mmio_base + SDW_SHIM_BASE;
119 link->alh = res->mmio_base + SDW_ALH_BASE;
121 link->ops = res->ops;
122 link->dev = res->dev;
124 memset(&pdevinfo, 0, sizeof(pdevinfo));
126 pdevinfo.parent = res->parent;
127 pdevinfo.name = "int-sdw";
129 pdevinfo.fwnode = acpi_fwnode_handle(adev);
131 pdev = platform_device_register_full(&pdevinfo);
134 "platform device creation failed: %ld\n",
146 sdw_intel_cleanup_pdev(ctx);
152 static acpi_status sdw_intel_acpi_cb(acpi_handle handle, u32 level,
153 void *cdata, void **return_value)
155 struct sdw_intel_res *res = cdata;
156 struct acpi_device *adev;
160 status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &adr);
161 if (ACPI_FAILURE(status))
162 return AE_OK; /* keep going */
164 if (acpi_bus_get_device(handle, &adev)) {
165 pr_err("%s: Couldn't find ACPI handle\n", __func__);
169 res->handle = handle;
172 * On some Intel platforms, multiple children of the HDAS
173 * device can be found, but only one of them is the SoundWire
174 * controller. The SNDW device is always exposed with
175 * Name(_ADR, 0x40000000), with bits 31..28 representing the
176 * SoundWire link so filter accordingly
178 if ((adr & GENMASK(31, 28)) >> 28 != SDW_LINK_TYPE)
179 return AE_OK; /* keep going */
181 /* device found, stop namespace walk */
182 return AE_CTRL_TERMINATE;
186 * sdw_intel_init() - SoundWire Intel init routine
187 * @parent_handle: ACPI parent handle
188 * @res: resource data
190 * This scans the namespace and creates SoundWire link controller devices
191 * based on the info queried.
193 void *sdw_intel_init(acpi_handle *parent_handle, struct sdw_intel_res *res)
197 status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
201 if (ACPI_FAILURE(status))
204 return sdw_intel_add_controller(res);
208 * sdw_intel_exit() - SoundWire Intel exit
209 * @arg: callback context
211 * Delete the controller instances created and cleanup
213 void sdw_intel_exit(struct sdw_intel_ctx *ctx)
215 sdw_intel_cleanup_pdev(ctx);
218 EXPORT_SYMBOL(sdw_intel_exit);
220 MODULE_LICENSE("Dual BSD/GPL");
221 MODULE_DESCRIPTION("Intel Soundwire Init Library");