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>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/soundwire/sdw_intel.h>
17 #define SDW_LINK_TYPE 4 /* from Intel ACPI documentation */
18 #define SDW_MAX_LINKS 4
19 #define SDW_SHIM_LCAP 0x0
20 #define SDW_SHIM_BASE 0x2C000
21 #define SDW_ALH_BASE 0x2C800
22 #define SDW_LINK_BASE 0x30000
23 #define SDW_LINK_SIZE 0x10000
25 struct sdw_link_data {
26 struct sdw_intel_link_res res;
27 struct platform_device *pdev;
30 struct sdw_intel_ctx {
32 struct sdw_link_data *links;
35 static int sdw_intel_cleanup_pdev(struct sdw_intel_ctx *ctx)
37 struct sdw_link_data *link = ctx->links;
43 for (i = 0; i < ctx->count; i++) {
45 platform_device_unregister(link->pdev);
55 static struct sdw_intel_ctx
56 *sdw_intel_add_controller(struct sdw_intel_res *res)
58 struct platform_device_info pdevinfo;
59 struct platform_device *pdev;
60 struct sdw_link_data *link;
61 struct sdw_intel_ctx *ctx;
62 struct acpi_device *adev;
67 if (acpi_bus_get_device(res->handle, &adev))
70 /* Found controller, find links supported */
72 ret = fwnode_property_read_u8_array(acpi_fwnode_handle(adev),
73 "mipi-sdw-master-count", &count, 1);
75 /* Don't fail on error, continue and use hw value */
78 "Failed to read mipi-sdw-master-count: %d\n", ret);
79 count = SDW_MAX_LINKS;
82 /* Check SNDWLCAP.LCOUNT */
83 caps = ioread32(res->mmio_base + SDW_SHIM_BASE + SDW_SHIM_LCAP);
84 caps &= GENMASK(2, 0);
86 /* Check HW supported vs property value and use min of two */
87 count = min_t(u8, caps, count);
89 /* Check count is within bounds */
90 if (count > SDW_MAX_LINKS) {
91 dev_err(&adev->dev, "Link count %d exceeds max %d\n",
92 count, SDW_MAX_LINKS);
95 dev_warn(&adev->dev, "No SoundWire links detected\n");
99 dev_dbg(&adev->dev, "Creating %d SDW Link devices\n", count);
101 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
106 ctx->links = kcalloc(ctx->count, sizeof(*ctx->links), GFP_KERNEL);
112 /* Create SDW Master devices */
113 for (i = 0; i < count; i++) {
114 link->res.irq = res->irq;
115 link->res.registers = res->mmio_base + SDW_LINK_BASE
116 + (SDW_LINK_SIZE * i);
117 link->res.shim = res->mmio_base + SDW_SHIM_BASE;
118 link->res.alh = res->mmio_base + SDW_ALH_BASE;
120 link->res.ops = res->ops;
121 link->res.arg = res->arg;
123 memset(&pdevinfo, 0, sizeof(pdevinfo));
125 pdevinfo.parent = res->parent;
126 pdevinfo.name = "int-sdw";
128 pdevinfo.fwnode = acpi_fwnode_handle(adev);
129 pdevinfo.data = &link->res;
130 pdevinfo.size_data = sizeof(link->res);
132 pdev = platform_device_register_full(&pdevinfo);
135 "platform device creation failed: %ld\n",
147 sdw_intel_cleanup_pdev(ctx);
153 static acpi_status sdw_intel_acpi_cb(acpi_handle handle, u32 level,
154 void *cdata, void **return_value)
156 struct sdw_intel_res *res = cdata;
157 struct acpi_device *adev;
161 status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &adr);
162 if (ACPI_FAILURE(status))
163 return AE_OK; /* keep going */
165 if (acpi_bus_get_device(handle, &adev)) {
166 pr_err("%s: Couldn't find ACPI handle\n", __func__);
170 res->handle = handle;
173 * On some Intel platforms, multiple children of the HDAS
174 * device can be found, but only one of them is the SoundWire
175 * controller. The SNDW device is always exposed with
176 * Name(_ADR, 0x40000000), with bits 31..28 representing the
177 * SoundWire link so filter accordingly
179 if ((adr & GENMASK(31, 28)) >> 28 != SDW_LINK_TYPE)
180 return AE_OK; /* keep going */
182 /* device found, stop namespace walk */
183 return AE_CTRL_TERMINATE;
187 * sdw_intel_init() - SoundWire Intel init routine
188 * @parent_handle: ACPI parent handle
189 * @res: resource data
191 * This scans the namespace and creates SoundWire link controller devices
192 * based on the info queried.
194 void *sdw_intel_init(acpi_handle *parent_handle, struct sdw_intel_res *res)
198 status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
202 if (ACPI_FAILURE(status))
205 return sdw_intel_add_controller(res);
207 EXPORT_SYMBOL(sdw_intel_init);
210 * sdw_intel_exit() - SoundWire Intel exit
211 * @arg: callback context
213 * Delete the controller instances created and cleanup
215 void sdw_intel_exit(void *arg)
217 struct sdw_intel_ctx *ctx = arg;
219 sdw_intel_cleanup_pdev(ctx);
222 EXPORT_SYMBOL(sdw_intel_exit);
224 MODULE_LICENSE("Dual BSD/GPL");
225 MODULE_DESCRIPTION("Intel Soundwire Init Library");