1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2 // Copyright(c) 2015-17 Intel Corporation.
3 
4 /*
5  * SDW Intel Init Routines
6  *
7  * Initializes and creates SDW devices based on ACPI and Hardware values
8  */
9 
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>
15 #include "intel.h"
16 
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
24 
25 static int link_mask;
26 module_param_named(sdw_link_mask, link_mask, int, 0444);
27 MODULE_PARM_DESC(sdw_link_mask, "Intel link mask (one bit per link)");
28 
29 struct sdw_link_data {
30 	struct sdw_intel_link_res res;
31 	struct platform_device *pdev;
32 };
33 
34 struct sdw_intel_ctx {
35 	int count;
36 	struct sdw_link_data *links;
37 };
38 
39 static int sdw_intel_cleanup_pdev(struct sdw_intel_ctx *ctx)
40 {
41 	struct sdw_link_data *link = ctx->links;
42 	int i;
43 
44 	if (!link)
45 		return 0;
46 
47 	for (i = 0; i < ctx->count; i++) {
48 		if (link->pdev)
49 			platform_device_unregister(link->pdev);
50 		link++;
51 	}
52 
53 	kfree(ctx->links);
54 	ctx->links = NULL;
55 
56 	return 0;
57 }
58 
59 static struct sdw_intel_ctx
60 *sdw_intel_add_controller(struct sdw_intel_res *res)
61 {
62 	struct platform_device_info pdevinfo;
63 	struct platform_device *pdev;
64 	struct sdw_link_data *link;
65 	struct sdw_intel_ctx *ctx;
66 	struct acpi_device *adev;
67 	int ret, i;
68 	u8 count;
69 	u32 caps;
70 
71 	if (acpi_bus_get_device(res->handle, &adev))
72 		return NULL;
73 
74 	/* Found controller, find links supported */
75 	count = 0;
76 	ret = fwnode_property_read_u8_array(acpi_fwnode_handle(adev),
77 					    "mipi-sdw-master-count", &count, 1);
78 
79 	/* Don't fail on error, continue and use hw value */
80 	if (ret) {
81 		dev_err(&adev->dev,
82 			"Failed to read mipi-sdw-master-count: %d\n", ret);
83 		count = SDW_MAX_LINKS;
84 	}
85 
86 	/* Check SNDWLCAP.LCOUNT */
87 	caps = ioread32(res->mmio_base + SDW_SHIM_BASE + SDW_SHIM_LCAP);
88 	caps &= GENMASK(2, 0);
89 
90 	/* Check HW supported vs property value and use min of two */
91 	count = min_t(u8, caps, count);
92 
93 	/* Check count is within bounds */
94 	if (count > SDW_MAX_LINKS) {
95 		dev_err(&adev->dev, "Link count %d exceeds max %d\n",
96 			count, SDW_MAX_LINKS);
97 		return NULL;
98 	} else if (!count) {
99 		dev_warn(&adev->dev, "No SoundWire links detected\n");
100 		return NULL;
101 	}
102 
103 	dev_dbg(&adev->dev, "Creating %d SDW Link devices\n", count);
104 
105 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
106 	if (!ctx)
107 		return NULL;
108 
109 	ctx->count = count;
110 	ctx->links = kcalloc(ctx->count, sizeof(*ctx->links), GFP_KERNEL);
111 	if (!ctx->links)
112 		goto link_err;
113 
114 	link = ctx->links;
115 
116 	/* Create SDW Master devices */
117 	for (i = 0; i < count; i++) {
118 		if (link_mask && !(link_mask & BIT(i))) {
119 			dev_dbg(&adev->dev,
120 				"Link %d masked, will not be enabled\n", i);
121 			link++;
122 			continue;
123 		}
124 
125 		link->res.irq = res->irq;
126 		link->res.registers = res->mmio_base + SDW_LINK_BASE
127 					+ (SDW_LINK_SIZE * i);
128 		link->res.shim = res->mmio_base + SDW_SHIM_BASE;
129 		link->res.alh = res->mmio_base + SDW_ALH_BASE;
130 
131 		link->res.ops = res->ops;
132 		link->res.arg = res->arg;
133 
134 		memset(&pdevinfo, 0, sizeof(pdevinfo));
135 
136 		pdevinfo.parent = res->parent;
137 		pdevinfo.name = "int-sdw";
138 		pdevinfo.id = i;
139 		pdevinfo.fwnode = acpi_fwnode_handle(adev);
140 		pdevinfo.data = &link->res;
141 		pdevinfo.size_data = sizeof(link->res);
142 
143 		pdev = platform_device_register_full(&pdevinfo);
144 		if (IS_ERR(pdev)) {
145 			dev_err(&adev->dev,
146 				"platform device creation failed: %ld\n",
147 				PTR_ERR(pdev));
148 			goto pdev_err;
149 		}
150 
151 		link->pdev = pdev;
152 		link++;
153 	}
154 
155 	return ctx;
156 
157 pdev_err:
158 	sdw_intel_cleanup_pdev(ctx);
159 link_err:
160 	kfree(ctx);
161 	return NULL;
162 }
163 
164 static acpi_status sdw_intel_acpi_cb(acpi_handle handle, u32 level,
165 				     void *cdata, void **return_value)
166 {
167 	struct sdw_intel_res *res = cdata;
168 	struct acpi_device *adev;
169 	acpi_status status;
170 	u64 adr;
171 
172 	status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &adr);
173 	if (ACPI_FAILURE(status))
174 		return AE_OK; /* keep going */
175 
176 	if (acpi_bus_get_device(handle, &adev)) {
177 		pr_err("%s: Couldn't find ACPI handle\n", __func__);
178 		return AE_NOT_FOUND;
179 	}
180 
181 	res->handle = handle;
182 
183 	/*
184 	 * On some Intel platforms, multiple children of the HDAS
185 	 * device can be found, but only one of them is the SoundWire
186 	 * controller. The SNDW device is always exposed with
187 	 * Name(_ADR, 0x40000000), with bits 31..28 representing the
188 	 * SoundWire link so filter accordingly
189 	 */
190 	if ((adr & GENMASK(31, 28)) >> 28 != SDW_LINK_TYPE)
191 		return AE_OK; /* keep going */
192 
193 	/* device found, stop namespace walk */
194 	return AE_CTRL_TERMINATE;
195 }
196 
197 /**
198  * sdw_intel_init() - SoundWire Intel init routine
199  * @parent_handle: ACPI parent handle
200  * @res: resource data
201  *
202  * This scans the namespace and creates SoundWire link controller devices
203  * based on the info queried.
204  */
205 void *sdw_intel_init(acpi_handle *parent_handle, struct sdw_intel_res *res)
206 {
207 	acpi_status status;
208 
209 	status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
210 				     parent_handle, 1,
211 				     sdw_intel_acpi_cb,
212 				     NULL, res, NULL);
213 	if (ACPI_FAILURE(status))
214 		return NULL;
215 
216 	return sdw_intel_add_controller(res);
217 }
218 EXPORT_SYMBOL(sdw_intel_init);
219 
220 /**
221  * sdw_intel_exit() - SoundWire Intel exit
222  * @arg: callback context
223  *
224  * Delete the controller instances created and cleanup
225  */
226 void sdw_intel_exit(void *arg)
227 {
228 	struct sdw_intel_ctx *ctx = arg;
229 
230 	sdw_intel_cleanup_pdev(ctx);
231 	kfree(ctx);
232 }
233 EXPORT_SYMBOL(sdw_intel_exit);
234 
235 MODULE_LICENSE("Dual BSD/GPL");
236 MODULE_DESCRIPTION("Intel Soundwire Init Library");
237