1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2 // Copyright(c) 2024 Intel Corporation
3
4 /*
5 * The MIPI SDCA specification is available for public downloads at
6 * https://www.mipi.org/mipi-sdca-v1-0-download
7 */
8
9 #include <linux/acpi.h>
10 #include <linux/soundwire/sdw.h>
11 #include <sound/sdca.h>
12 #include <sound/sdca_function.h>
13
patch_sdca_function_type(struct device * dev,u32 interface_revision,u32 * function_type,const char ** function_name)14 static int patch_sdca_function_type(struct device *dev,
15 u32 interface_revision,
16 u32 *function_type,
17 const char **function_name)
18 {
19 unsigned long function_type_patch = 0;
20
21 /*
22 * Unfortunately early SDCA specifications used different indices for Functions,
23 * for backwards compatibility we have to reorder the values found
24 */
25 if (interface_revision >= 0x0801)
26 goto skip_early_draft_order;
27
28 switch (*function_type) {
29 case 1:
30 function_type_patch = SDCA_FUNCTION_TYPE_SMART_AMP;
31 break;
32 case 2:
33 function_type_patch = SDCA_FUNCTION_TYPE_SMART_MIC;
34 break;
35 case 3:
36 function_type_patch = SDCA_FUNCTION_TYPE_SPEAKER_MIC;
37 break;
38 case 4:
39 function_type_patch = SDCA_FUNCTION_TYPE_UAJ;
40 break;
41 case 5:
42 function_type_patch = SDCA_FUNCTION_TYPE_RJ;
43 break;
44 case 6:
45 function_type_patch = SDCA_FUNCTION_TYPE_HID;
46 break;
47 default:
48 dev_warn(dev, "%s: SDCA version %#x unsupported function type %d, skipped\n",
49 __func__, interface_revision, *function_type);
50 return -EINVAL;
51 }
52
53 skip_early_draft_order:
54 if (function_type_patch)
55 *function_type = function_type_patch;
56
57 /* now double-check the values */
58 switch (*function_type) {
59 case SDCA_FUNCTION_TYPE_SMART_AMP:
60 *function_name = SDCA_FUNCTION_TYPE_SMART_AMP_NAME;
61 break;
62 case SDCA_FUNCTION_TYPE_SMART_MIC:
63 *function_name = SDCA_FUNCTION_TYPE_SMART_MIC_NAME;
64 break;
65 case SDCA_FUNCTION_TYPE_UAJ:
66 *function_name = SDCA_FUNCTION_TYPE_UAJ_NAME;
67 break;
68 case SDCA_FUNCTION_TYPE_HID:
69 *function_name = SDCA_FUNCTION_TYPE_HID_NAME;
70 break;
71 case SDCA_FUNCTION_TYPE_SIMPLE_AMP:
72 case SDCA_FUNCTION_TYPE_SIMPLE_MIC:
73 case SDCA_FUNCTION_TYPE_SPEAKER_MIC:
74 case SDCA_FUNCTION_TYPE_RJ:
75 case SDCA_FUNCTION_TYPE_IMP_DEF:
76 dev_warn(dev, "%s: found unsupported SDCA function type %d, skipped\n",
77 __func__, *function_type);
78 return -EINVAL;
79 default:
80 dev_err(dev, "%s: found invalid SDCA function type %d, skipped\n",
81 __func__, *function_type);
82 return -EINVAL;
83 }
84
85 dev_info(dev, "%s: found SDCA function %s (type %d)\n",
86 __func__, *function_name, *function_type);
87
88 return 0;
89 }
90
find_sdca_function(struct acpi_device * adev,void * data)91 static int find_sdca_function(struct acpi_device *adev, void *data)
92 {
93 struct fwnode_handle *function_node = acpi_fwnode_handle(adev);
94 struct sdca_device_data *sdca_data = data;
95 struct device *dev = &adev->dev;
96 struct fwnode_handle *control5; /* used to identify function type */
97 const char *function_name;
98 u32 function_type;
99 int func_index;
100 u64 addr;
101 int ret;
102
103 if (sdca_data->num_functions >= SDCA_MAX_FUNCTION_COUNT) {
104 dev_err(dev, "%s: maximum number of functions exceeded\n", __func__);
105 return -EINVAL;
106 }
107
108 /*
109 * The number of functions cannot exceed 8, we could use
110 * acpi_get_local_address() but the value is stored as u64 so
111 * we might as well avoid casts and intermediate levels
112 */
113 ret = acpi_get_local_u64_address(adev->handle, &addr);
114 if (ret < 0)
115 return ret;
116
117 if (!addr) {
118 dev_err(dev, "%s: no addr\n", __func__);
119 return -ENODEV;
120 }
121
122 /*
123 * Extracting the topology type for an SDCA function is a
124 * convoluted process.
125 * The Function type is only visible as a result of a read
126 * from a control. In theory this would mean reading from the hardware,
127 * but the SDCA/DisCo specs defined the notion of "DC value" - a constant
128 * represented with a DSD subproperty.
129 * Drivers have to query the properties for the control
130 * SDCA_CONTROL_ENTITY_0_FUNCTION_TOPOLOGY (0x05)
131 */
132 control5 = fwnode_get_named_child_node(function_node,
133 "mipi-sdca-control-0x5-subproperties");
134 if (!control5)
135 return -ENODEV;
136
137 ret = fwnode_property_read_u32(control5, "mipi-sdca-control-dc-value",
138 &function_type);
139
140 fwnode_handle_put(control5);
141
142 if (ret < 0) {
143 dev_err(dev, "%s: the function type can only be determined from ACPI information\n",
144 __func__);
145 return ret;
146 }
147
148 ret = patch_sdca_function_type(dev, sdca_data->interface_revision,
149 &function_type, &function_name);
150 if (ret < 0)
151 return ret;
152
153 /* store results */
154 func_index = sdca_data->num_functions;
155 sdca_data->sdca_func[func_index].adr = addr;
156 sdca_data->sdca_func[func_index].type = function_type;
157 sdca_data->sdca_func[func_index].name = function_name;
158 sdca_data->num_functions++;
159
160 return 0;
161 }
162
sdca_lookup_functions(struct sdw_slave * slave)163 void sdca_lookup_functions(struct sdw_slave *slave)
164 {
165 struct device *dev = &slave->dev;
166 struct acpi_device *adev = to_acpi_device_node(dev->fwnode);
167
168 if (!adev) {
169 dev_info(dev, "No matching ACPI device found, ignoring peripheral\n");
170 return;
171 }
172 acpi_dev_for_each_child(adev, find_sdca_function, &slave->sdca_data);
173 }
174 EXPORT_SYMBOL_NS(sdca_lookup_functions, "SND_SOC_SDCA");
175
176 MODULE_LICENSE("Dual BSD/GPL");
177 MODULE_DESCRIPTION("SDCA library");
178