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_MAX_LINKS		4
18 #define SDW_SHIM_LCAP		0x0
19 #define SDW_SHIM_BASE		0x2C000
20 #define SDW_ALH_BASE		0x2C800
21 #define SDW_LINK_BASE		0x30000
22 #define SDW_LINK_SIZE		0x10000
23 
24 struct sdw_link_data {
25 	struct sdw_intel_link_res res;
26 	struct platform_device *pdev;
27 };
28 
29 struct sdw_intel_ctx {
30 	int count;
31 	struct sdw_link_data *links;
32 };
33 
34 static int sdw_intel_cleanup_pdev(struct sdw_intel_ctx *ctx)
35 {
36 	struct sdw_link_data *link = ctx->links;
37 	int i;
38 
39 	if (!link)
40 		return 0;
41 
42 	for (i = 0; i < ctx->count; i++) {
43 		if (link->pdev)
44 			platform_device_unregister(link->pdev);
45 		link++;
46 	}
47 
48 	kfree(ctx->links);
49 	ctx->links = NULL;
50 
51 	return 0;
52 }
53 
54 static struct sdw_intel_ctx
55 *sdw_intel_add_controller(struct sdw_intel_res *res)
56 {
57 	struct platform_device_info pdevinfo;
58 	struct platform_device *pdev;
59 	struct sdw_link_data *link;
60 	struct sdw_intel_ctx *ctx;
61 	struct acpi_device *adev;
62 	int ret, i;
63 	u8 count;
64 	u32 caps;
65 
66 	if (acpi_bus_get_device(res->handle, &adev))
67 		return NULL;
68 
69 	/* Found controller, find links supported */
70 	count = 0;
71 	ret = fwnode_property_read_u8_array(acpi_fwnode_handle(adev),
72 					    "mipi-sdw-master-count", &count, 1);
73 
74 	/* Don't fail on error, continue and use hw value */
75 	if (ret) {
76 		dev_err(&adev->dev,
77 			"Failed to read mipi-sdw-master-count: %d\n", ret);
78 		count = SDW_MAX_LINKS;
79 	}
80 
81 	/* Check SNDWLCAP.LCOUNT */
82 	caps = ioread32(res->mmio_base + SDW_SHIM_BASE + SDW_SHIM_LCAP);
83 
84 	/* Check HW supported vs property value and use min of two */
85 	count = min_t(u8, caps, count);
86 
87 	/* Check count is within bounds */
88 	if (count > SDW_MAX_LINKS) {
89 		dev_err(&adev->dev, "Link count %d exceeds max %d\n",
90 			count, SDW_MAX_LINKS);
91 		return NULL;
92 	}
93 
94 	dev_dbg(&adev->dev, "Creating %d SDW Link devices\n", count);
95 
96 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
97 	if (!ctx)
98 		return NULL;
99 
100 	ctx->count = count;
101 	ctx->links = kcalloc(ctx->count, sizeof(*ctx->links), GFP_KERNEL);
102 	if (!ctx->links)
103 		goto link_err;
104 
105 	link = ctx->links;
106 
107 	/* Create SDW Master devices */
108 	for (i = 0; i < count; i++) {
109 		link->res.irq = res->irq;
110 		link->res.registers = res->mmio_base + SDW_LINK_BASE
111 					+ (SDW_LINK_SIZE * i);
112 		link->res.shim = res->mmio_base + SDW_SHIM_BASE;
113 		link->res.alh = res->mmio_base + SDW_ALH_BASE;
114 
115 		link->res.ops = res->ops;
116 		link->res.arg = res->arg;
117 
118 		memset(&pdevinfo, 0, sizeof(pdevinfo));
119 
120 		pdevinfo.parent = res->parent;
121 		pdevinfo.name = "int-sdw";
122 		pdevinfo.id = i;
123 		pdevinfo.fwnode = acpi_fwnode_handle(adev);
124 		pdevinfo.data = &link->res;
125 		pdevinfo.size_data = sizeof(link->res);
126 
127 		pdev = platform_device_register_full(&pdevinfo);
128 		if (IS_ERR(pdev)) {
129 			dev_err(&adev->dev,
130 				"platform device creation failed: %ld\n",
131 				PTR_ERR(pdev));
132 			goto pdev_err;
133 		}
134 
135 		link->pdev = pdev;
136 		link++;
137 	}
138 
139 	return ctx;
140 
141 pdev_err:
142 	sdw_intel_cleanup_pdev(ctx);
143 link_err:
144 	kfree(ctx);
145 	return NULL;
146 }
147 
148 static acpi_status sdw_intel_acpi_cb(acpi_handle handle, u32 level,
149 				     void *cdata, void **return_value)
150 {
151 	struct sdw_intel_res *res = cdata;
152 	struct acpi_device *adev;
153 
154 	if (acpi_bus_get_device(handle, &adev)) {
155 		pr_err("%s: Couldn't find ACPI handle\n", __func__);
156 		return AE_NOT_FOUND;
157 	}
158 
159 	res->handle = handle;
160 	return AE_OK;
161 }
162 
163 /**
164  * sdw_intel_init() - SoundWire Intel init routine
165  * @parent_handle: ACPI parent handle
166  * @res: resource data
167  *
168  * This scans the namespace and creates SoundWire link controller devices
169  * based on the info queried.
170  */
171 void *sdw_intel_init(acpi_handle *parent_handle, struct sdw_intel_res *res)
172 {
173 	acpi_status status;
174 
175 	status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
176 				     parent_handle, 1,
177 				     sdw_intel_acpi_cb,
178 				     NULL, res, NULL);
179 	if (ACPI_FAILURE(status))
180 		return NULL;
181 
182 	return sdw_intel_add_controller(res);
183 }
184 EXPORT_SYMBOL(sdw_intel_init);
185 
186 /**
187  * sdw_intel_exit() - SoundWire Intel exit
188  * @arg: callback context
189  *
190  * Delete the controller instances created and cleanup
191  */
192 void sdw_intel_exit(void *arg)
193 {
194 	struct sdw_intel_ctx *ctx = arg;
195 
196 	sdw_intel_cleanup_pdev(ctx);
197 	kfree(ctx);
198 }
199 EXPORT_SYMBOL(sdw_intel_exit);
200 
201 MODULE_LICENSE("Dual BSD/GPL");
202 MODULE_DESCRIPTION("Intel Soundwire Init Library");
203