1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * UCSI ACPI driver
4 *
5 * Copyright (C) 2017, Intel Corporation
6 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
7 */
8
9 #include <linux/platform_device.h>
10 #include <linux/module.h>
11 #include <linux/acpi.h>
12
13 #include "ucsi.h"
14
15 #define UCSI_DSM_UUID "6f8398c2-7ca4-11e4-ad36-631042b5008f"
16 #define UCSI_DSM_FUNC_WRITE 1
17 #define UCSI_DSM_FUNC_READ 2
18
19 struct ucsi_acpi {
20 struct device *dev;
21 struct ucsi *ucsi;
22 void __iomem *base;
23 struct completion complete;
24 unsigned long flags;
25 guid_t guid;
26 };
27
ucsi_acpi_dsm(struct ucsi_acpi * ua,int func)28 static int ucsi_acpi_dsm(struct ucsi_acpi *ua, int func)
29 {
30 union acpi_object *obj;
31
32 obj = acpi_evaluate_dsm(ACPI_HANDLE(ua->dev), &ua->guid, 1, func,
33 NULL);
34 if (!obj) {
35 dev_err(ua->dev, "%s: failed to evaluate _DSM %d\n",
36 __func__, func);
37 return -EIO;
38 }
39
40 ACPI_FREE(obj);
41 return 0;
42 }
43
ucsi_acpi_read(struct ucsi * ucsi,unsigned int offset,void * val,size_t val_len)44 static int ucsi_acpi_read(struct ucsi *ucsi, unsigned int offset,
45 void *val, size_t val_len)
46 {
47 struct ucsi_acpi *ua = ucsi_get_drvdata(ucsi);
48 int ret;
49
50 ret = ucsi_acpi_dsm(ua, UCSI_DSM_FUNC_READ);
51 if (ret)
52 return ret;
53
54 memcpy(val, (const void __force *)(ua->base + offset), val_len);
55
56 return 0;
57 }
58
ucsi_acpi_async_write(struct ucsi * ucsi,unsigned int offset,const void * val,size_t val_len)59 static int ucsi_acpi_async_write(struct ucsi *ucsi, unsigned int offset,
60 const void *val, size_t val_len)
61 {
62 struct ucsi_acpi *ua = ucsi_get_drvdata(ucsi);
63
64 memcpy((void __force *)(ua->base + offset), val, val_len);
65
66 return ucsi_acpi_dsm(ua, UCSI_DSM_FUNC_WRITE);
67 }
68
ucsi_acpi_sync_write(struct ucsi * ucsi,unsigned int offset,const void * val,size_t val_len)69 static int ucsi_acpi_sync_write(struct ucsi *ucsi, unsigned int offset,
70 const void *val, size_t val_len)
71 {
72 struct ucsi_acpi *ua = ucsi_get_drvdata(ucsi);
73 int ret;
74
75 set_bit(COMMAND_PENDING, &ua->flags);
76
77 ret = ucsi_acpi_async_write(ucsi, offset, val, val_len);
78 if (ret)
79 goto out_clear_bit;
80
81 if (!wait_for_completion_timeout(&ua->complete, 60 * HZ))
82 ret = -ETIMEDOUT;
83
84 out_clear_bit:
85 clear_bit(COMMAND_PENDING, &ua->flags);
86
87 return ret;
88 }
89
90 static const struct ucsi_operations ucsi_acpi_ops = {
91 .read = ucsi_acpi_read,
92 .sync_write = ucsi_acpi_sync_write,
93 .async_write = ucsi_acpi_async_write
94 };
95
ucsi_acpi_notify(acpi_handle handle,u32 event,void * data)96 static void ucsi_acpi_notify(acpi_handle handle, u32 event, void *data)
97 {
98 struct ucsi_acpi *ua = data;
99 u32 cci;
100 int ret;
101
102 ret = ucsi_acpi_read(ua->ucsi, UCSI_CCI, &cci, sizeof(cci));
103 if (ret)
104 return;
105
106 if (test_bit(COMMAND_PENDING, &ua->flags) &&
107 cci & (UCSI_CCI_ACK_COMPLETE | UCSI_CCI_COMMAND_COMPLETE))
108 complete(&ua->complete);
109 else if (UCSI_CCI_CONNECTOR(cci))
110 ucsi_connector_change(ua->ucsi, UCSI_CCI_CONNECTOR(cci));
111 }
112
ucsi_acpi_probe(struct platform_device * pdev)113 static int ucsi_acpi_probe(struct platform_device *pdev)
114 {
115 struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
116 struct ucsi_acpi *ua;
117 struct resource *res;
118 acpi_status status;
119 int ret;
120
121 if (adev->dep_unmet)
122 return -EPROBE_DEFER;
123
124 ua = devm_kzalloc(&pdev->dev, sizeof(*ua), GFP_KERNEL);
125 if (!ua)
126 return -ENOMEM;
127
128 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
129 if (!res) {
130 dev_err(&pdev->dev, "missing memory resource\n");
131 return -ENODEV;
132 }
133
134 /* This will make sure we can use ioremap() */
135 status = acpi_release_memory(ACPI_HANDLE(&pdev->dev), res, 1);
136 if (ACPI_FAILURE(status))
137 return -ENOMEM;
138
139 /*
140 * NOTE: The memory region for the data structures is used also in an
141 * operation region, which means ACPI has already reserved it. Therefore
142 * it can not be requested here, and we can not use
143 * devm_ioremap_resource().
144 */
145 ua->base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
146 if (!ua->base)
147 return -ENOMEM;
148
149 ret = guid_parse(UCSI_DSM_UUID, &ua->guid);
150 if (ret)
151 return ret;
152
153 init_completion(&ua->complete);
154 ua->dev = &pdev->dev;
155
156 ua->ucsi = ucsi_create(&pdev->dev, &ucsi_acpi_ops);
157 if (IS_ERR(ua->ucsi))
158 return PTR_ERR(ua->ucsi);
159
160 ucsi_set_drvdata(ua->ucsi, ua);
161
162 status = acpi_install_notify_handler(ACPI_HANDLE(&pdev->dev),
163 ACPI_DEVICE_NOTIFY,
164 ucsi_acpi_notify, ua);
165 if (ACPI_FAILURE(status)) {
166 dev_err(&pdev->dev, "failed to install notify handler\n");
167 ucsi_destroy(ua->ucsi);
168 return -ENODEV;
169 }
170
171 ret = ucsi_register(ua->ucsi);
172 if (ret) {
173 acpi_remove_notify_handler(ACPI_HANDLE(&pdev->dev),
174 ACPI_DEVICE_NOTIFY,
175 ucsi_acpi_notify);
176 ucsi_destroy(ua->ucsi);
177 return ret;
178 }
179
180 platform_set_drvdata(pdev, ua);
181
182 return 0;
183 }
184
ucsi_acpi_remove(struct platform_device * pdev)185 static int ucsi_acpi_remove(struct platform_device *pdev)
186 {
187 struct ucsi_acpi *ua = platform_get_drvdata(pdev);
188
189 ucsi_unregister(ua->ucsi);
190 ucsi_destroy(ua->ucsi);
191
192 acpi_remove_notify_handler(ACPI_HANDLE(&pdev->dev), ACPI_DEVICE_NOTIFY,
193 ucsi_acpi_notify);
194
195 return 0;
196 }
197
198 static const struct acpi_device_id ucsi_acpi_match[] = {
199 { "PNP0CA0", 0 },
200 { },
201 };
202 MODULE_DEVICE_TABLE(acpi, ucsi_acpi_match);
203
204 static struct platform_driver ucsi_acpi_platform_driver = {
205 .driver = {
206 .name = "ucsi_acpi",
207 .acpi_match_table = ACPI_PTR(ucsi_acpi_match),
208 },
209 .probe = ucsi_acpi_probe,
210 .remove = ucsi_acpi_remove,
211 };
212
213 module_platform_driver(ucsi_acpi_platform_driver);
214
215 MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
216 MODULE_LICENSE("GPL v2");
217 MODULE_DESCRIPTION("UCSI ACPI driver");
218