1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2022-2023 Intel Corporation
4 */
5
6 /**
7 * DOC: MEI_GSC_PROXY Client Driver
8 *
9 * The mei_gsc_proxy driver acts as a translation layer between
10 * proxy user (I915) and ME FW by proxying messages to ME FW
11 */
12
13 #include <linux/component.h>
14 #include <linux/mei_cl_bus.h>
15 #include <linux/module.h>
16 #include <linux/pci.h>
17 #include <linux/slab.h>
18 #include <linux/uuid.h>
19 #include <drm/drm_connector.h>
20 #include <drm/intel/i915_component.h>
21 #include <drm/intel/i915_gsc_proxy_mei_interface.h>
22
23 /**
24 * mei_gsc_proxy_send - Sends a proxy message to ME FW.
25 * @dev: device corresponding to the mei_cl_device
26 * @buf: a message buffer to send
27 * @size: size of the message
28 * Return: bytes sent on Success, <0 on Failure
29 */
mei_gsc_proxy_send(struct device * dev,const void * buf,size_t size)30 static int mei_gsc_proxy_send(struct device *dev, const void *buf, size_t size)
31 {
32 ssize_t ret;
33
34 if (!dev || !buf)
35 return -EINVAL;
36
37 ret = mei_cldev_send(to_mei_cl_device(dev), buf, size);
38 if (ret < 0)
39 dev_dbg(dev, "mei_cldev_send failed. %zd\n", ret);
40
41 return ret;
42 }
43
44 /**
45 * mei_gsc_proxy_recv - Receives a proxy message from ME FW.
46 * @dev: device corresponding to the mei_cl_device
47 * @buf: a message buffer to contain the received message
48 * @size: size of the buffer
49 * Return: bytes received on Success, <0 on Failure
50 */
mei_gsc_proxy_recv(struct device * dev,void * buf,size_t size)51 static int mei_gsc_proxy_recv(struct device *dev, void *buf, size_t size)
52 {
53 ssize_t ret;
54
55 if (!dev || !buf)
56 return -EINVAL;
57
58 ret = mei_cldev_recv(to_mei_cl_device(dev), buf, size);
59 if (ret < 0)
60 dev_dbg(dev, "mei_cldev_recv failed. %zd\n", ret);
61
62 return ret;
63 }
64
65 static const struct i915_gsc_proxy_component_ops mei_gsc_proxy_ops = {
66 .owner = THIS_MODULE,
67 .send = mei_gsc_proxy_send,
68 .recv = mei_gsc_proxy_recv,
69 };
70
mei_component_master_bind(struct device * dev)71 static int mei_component_master_bind(struct device *dev)
72 {
73 struct mei_cl_device *cldev = to_mei_cl_device(dev);
74 struct i915_gsc_proxy_component *comp_master = mei_cldev_get_drvdata(cldev);
75
76 comp_master->ops = &mei_gsc_proxy_ops;
77 comp_master->mei_dev = dev;
78 return component_bind_all(dev, comp_master);
79 }
80
mei_component_master_unbind(struct device * dev)81 static void mei_component_master_unbind(struct device *dev)
82 {
83 struct mei_cl_device *cldev = to_mei_cl_device(dev);
84 struct i915_gsc_proxy_component *comp_master = mei_cldev_get_drvdata(cldev);
85
86 component_unbind_all(dev, comp_master);
87 }
88
89 static const struct component_master_ops mei_component_master_ops = {
90 .bind = mei_component_master_bind,
91 .unbind = mei_component_master_unbind,
92 };
93
94 /**
95 * mei_gsc_proxy_component_match - compare function for matching mei.
96 *
97 * The function checks if the device is pci device and
98 * Intel VGA adapter, the subcomponent is SW Proxy
99 * and the VGA is on the bus 0 reserved for built-in devices
100 * to reject discrete GFX.
101 *
102 * @dev: master device
103 * @subcomponent: subcomponent to match (I915_COMPONENT_SWPROXY)
104 * @data: compare data (mei pci parent)
105 *
106 * Return:
107 * * 1 - if components match
108 * * 0 - otherwise
109 */
mei_gsc_proxy_component_match(struct device * dev,int subcomponent,void * data)110 static int mei_gsc_proxy_component_match(struct device *dev, int subcomponent,
111 void *data)
112 {
113 struct pci_dev *pdev;
114
115 if (!dev_is_pci(dev))
116 return 0;
117
118 pdev = to_pci_dev(dev);
119
120 if (pdev->class != (PCI_CLASS_DISPLAY_VGA << 8) ||
121 pdev->vendor != PCI_VENDOR_ID_INTEL)
122 return 0;
123
124 if (subcomponent != I915_COMPONENT_GSC_PROXY)
125 return 0;
126
127 /* Only built-in GFX */
128 return (pdev->bus->number == 0);
129 }
130
mei_gsc_proxy_probe(struct mei_cl_device * cldev,const struct mei_cl_device_id * id)131 static int mei_gsc_proxy_probe(struct mei_cl_device *cldev,
132 const struct mei_cl_device_id *id)
133 {
134 struct i915_gsc_proxy_component *comp_master;
135 struct component_match *master_match = NULL;
136 int ret;
137
138 ret = mei_cldev_enable(cldev);
139 if (ret < 0) {
140 dev_err(&cldev->dev, "mei_cldev_enable Failed. %d\n", ret);
141 goto enable_err_exit;
142 }
143
144 comp_master = kzalloc(sizeof(*comp_master), GFP_KERNEL);
145 if (!comp_master) {
146 ret = -ENOMEM;
147 goto err_exit;
148 }
149
150 component_match_add_typed(&cldev->dev, &master_match,
151 mei_gsc_proxy_component_match, NULL);
152 if (IS_ERR_OR_NULL(master_match)) {
153 ret = -ENOMEM;
154 goto err_exit;
155 }
156
157 mei_cldev_set_drvdata(cldev, comp_master);
158 ret = component_master_add_with_match(&cldev->dev,
159 &mei_component_master_ops,
160 master_match);
161 if (ret < 0) {
162 dev_err(&cldev->dev, "Master comp add failed %d\n", ret);
163 goto err_exit;
164 }
165
166 return 0;
167
168 err_exit:
169 mei_cldev_set_drvdata(cldev, NULL);
170 kfree(comp_master);
171 mei_cldev_disable(cldev);
172 enable_err_exit:
173 return ret;
174 }
175
mei_gsc_proxy_remove(struct mei_cl_device * cldev)176 static void mei_gsc_proxy_remove(struct mei_cl_device *cldev)
177 {
178 struct i915_gsc_proxy_component *comp_master = mei_cldev_get_drvdata(cldev);
179 int ret;
180
181 component_master_del(&cldev->dev, &mei_component_master_ops);
182 kfree(comp_master);
183 mei_cldev_set_drvdata(cldev, NULL);
184
185 ret = mei_cldev_disable(cldev);
186 if (ret)
187 dev_warn(&cldev->dev, "mei_cldev_disable() failed %d\n", ret);
188 }
189
190 #define MEI_UUID_GSC_PROXY UUID_LE(0xf73db04, 0x97ab, 0x4125, \
191 0xb8, 0x93, 0xe9, 0x4, 0xad, 0xd, 0x54, 0x64)
192
193 static struct mei_cl_device_id mei_gsc_proxy_tbl[] = {
194 { .uuid = MEI_UUID_GSC_PROXY, .version = MEI_CL_VERSION_ANY },
195 { }
196 };
197 MODULE_DEVICE_TABLE(mei, mei_gsc_proxy_tbl);
198
199 static struct mei_cl_driver mei_gsc_proxy_driver = {
200 .id_table = mei_gsc_proxy_tbl,
201 .name = KBUILD_MODNAME,
202 .probe = mei_gsc_proxy_probe,
203 .remove = mei_gsc_proxy_remove,
204 };
205
206 module_mei_cl_driver(mei_gsc_proxy_driver);
207
208 MODULE_AUTHOR("Intel Corporation");
209 MODULE_LICENSE("GPL");
210 MODULE_DESCRIPTION("MEI GSC PROXY");
211