1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * lenovo-ymc.c - Lenovo Yoga Mode Control driver
4 *
5 * Copyright © 2022 Gergo Koteles <soyer@irl.hu>
6 */
7
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10 #include <linux/acpi.h>
11 #include <linux/dmi.h>
12 #include <linux/input.h>
13 #include <linux/input/sparse-keymap.h>
14 #include <linux/wmi.h>
15 #include "ideapad-laptop.h"
16
17 #define LENOVO_YMC_EVENT_GUID "06129D99-6083-4164-81AD-F092F9D773A6"
18 #define LENOVO_YMC_QUERY_GUID "09B0EE6E-C3FD-4243-8DA1-7911FF80BB8C"
19
20 #define LENOVO_YMC_QUERY_INSTANCE 0
21 #define LENOVO_YMC_QUERY_METHOD 0x01
22
23 static bool ec_trigger __read_mostly;
24 module_param(ec_trigger, bool, 0444);
25 MODULE_PARM_DESC(ec_trigger, "Enable EC triggering work-around to force emitting tablet mode events");
26
27 static bool force;
28 module_param(force, bool, 0444);
29 MODULE_PARM_DESC(force, "Force loading on boards without a convertible DMI chassis-type");
30
31 static const struct dmi_system_id ec_trigger_quirk_dmi_table[] = {
32 {
33 /* Lenovo Yoga 7 14ARB7 */
34 .matches = {
35 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
36 DMI_MATCH(DMI_PRODUCT_NAME, "82QF"),
37 },
38 },
39 {
40 /* Lenovo Yoga 7 14ACN6 */
41 .matches = {
42 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
43 DMI_MATCH(DMI_PRODUCT_NAME, "82N7"),
44 },
45 },
46 { }
47 };
48
49 static const struct dmi_system_id allowed_chasis_types_dmi_table[] = {
50 {
51 .matches = {
52 DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "31" /* Convertible */),
53 },
54 },
55 {
56 .matches = {
57 DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "32" /* Detachable */),
58 },
59 },
60 { }
61 };
62
63 struct lenovo_ymc_private {
64 struct input_dev *input_dev;
65 struct acpi_device *ec_acpi_dev;
66 };
67
lenovo_ymc_trigger_ec(struct wmi_device * wdev,struct lenovo_ymc_private * priv)68 static void lenovo_ymc_trigger_ec(struct wmi_device *wdev, struct lenovo_ymc_private *priv)
69 {
70 int err;
71
72 if (!priv->ec_acpi_dev)
73 return;
74
75 err = write_ec_cmd(priv->ec_acpi_dev->handle, VPCCMD_W_YMC, 1);
76 if (err)
77 dev_warn(&wdev->dev, "Could not write YMC: %d\n", err);
78 }
79
80 static const struct key_entry lenovo_ymc_keymap[] = {
81 /* Laptop */
82 { KE_SW, 0x01, { .sw = { SW_TABLET_MODE, 0 } } },
83 /* Tablet */
84 { KE_SW, 0x02, { .sw = { SW_TABLET_MODE, 1 } } },
85 /* Drawing Board */
86 { KE_SW, 0x03, { .sw = { SW_TABLET_MODE, 1 } } },
87 /* Tent */
88 { KE_SW, 0x04, { .sw = { SW_TABLET_MODE, 1 } } },
89 { KE_END },
90 };
91
lenovo_ymc_notify(struct wmi_device * wdev,union acpi_object * data)92 static void lenovo_ymc_notify(struct wmi_device *wdev, union acpi_object *data)
93 {
94 struct lenovo_ymc_private *priv = dev_get_drvdata(&wdev->dev);
95 u32 input_val = 0;
96 struct acpi_buffer input = { sizeof(input_val), &input_val };
97 struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
98 union acpi_object *obj;
99 acpi_status status;
100 int code;
101
102 status = wmi_evaluate_method(LENOVO_YMC_QUERY_GUID,
103 LENOVO_YMC_QUERY_INSTANCE,
104 LENOVO_YMC_QUERY_METHOD,
105 &input, &output);
106
107 if (ACPI_FAILURE(status)) {
108 dev_warn(&wdev->dev,
109 "Failed to evaluate query method: %s\n",
110 acpi_format_exception(status));
111 return;
112 }
113
114 obj = output.pointer;
115
116 if (obj->type != ACPI_TYPE_INTEGER) {
117 dev_warn(&wdev->dev,
118 "WMI event data is not an integer\n");
119 goto free_obj;
120 }
121 code = obj->integer.value;
122
123 if (!sparse_keymap_report_event(priv->input_dev, code, 1, true))
124 dev_warn(&wdev->dev, "Unknown key %d pressed\n", code);
125
126 free_obj:
127 kfree(obj);
128 lenovo_ymc_trigger_ec(wdev, priv);
129 }
130
acpi_dev_put_helper(void * p)131 static void acpi_dev_put_helper(void *p) { acpi_dev_put(p); }
132
lenovo_ymc_probe(struct wmi_device * wdev,const void * ctx)133 static int lenovo_ymc_probe(struct wmi_device *wdev, const void *ctx)
134 {
135 struct lenovo_ymc_private *priv;
136 struct input_dev *input_dev;
137 int err;
138
139 if (!dmi_check_system(allowed_chasis_types_dmi_table)) {
140 if (force)
141 dev_info(&wdev->dev, "Force loading Lenovo YMC support\n");
142 else
143 return -ENODEV;
144 }
145
146 ec_trigger |= dmi_check_system(ec_trigger_quirk_dmi_table);
147
148 priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);
149 if (!priv)
150 return -ENOMEM;
151
152 if (ec_trigger) {
153 pr_debug("Lenovo YMC enable EC triggering.\n");
154 priv->ec_acpi_dev = acpi_dev_get_first_match_dev("VPC2004", NULL, -1);
155
156 if (!priv->ec_acpi_dev) {
157 dev_err(&wdev->dev, "Could not find EC ACPI device.\n");
158 return -ENODEV;
159 }
160 err = devm_add_action_or_reset(&wdev->dev,
161 acpi_dev_put_helper, priv->ec_acpi_dev);
162 if (err) {
163 dev_err(&wdev->dev,
164 "Could not clean up EC ACPI device: %d\n", err);
165 return err;
166 }
167 }
168
169 input_dev = devm_input_allocate_device(&wdev->dev);
170 if (!input_dev)
171 return -ENOMEM;
172
173 input_dev->name = "Lenovo Yoga Tablet Mode Control switch";
174 input_dev->phys = LENOVO_YMC_EVENT_GUID "/input0";
175 input_dev->id.bustype = BUS_HOST;
176 input_dev->dev.parent = &wdev->dev;
177 err = sparse_keymap_setup(input_dev, lenovo_ymc_keymap, NULL);
178 if (err) {
179 dev_err(&wdev->dev,
180 "Could not set up input device keymap: %d\n", err);
181 return err;
182 }
183
184 err = input_register_device(input_dev);
185 if (err) {
186 dev_err(&wdev->dev,
187 "Could not register input device: %d\n", err);
188 return err;
189 }
190
191 priv->input_dev = input_dev;
192 dev_set_drvdata(&wdev->dev, priv);
193
194 /* Report the state for the first time on probe */
195 lenovo_ymc_trigger_ec(wdev, priv);
196 lenovo_ymc_notify(wdev, NULL);
197 return 0;
198 }
199
200 static const struct wmi_device_id lenovo_ymc_wmi_id_table[] = {
201 { .guid_string = LENOVO_YMC_EVENT_GUID },
202 { }
203 };
204 MODULE_DEVICE_TABLE(wmi, lenovo_ymc_wmi_id_table);
205
206 static struct wmi_driver lenovo_ymc_driver = {
207 .driver = {
208 .name = "lenovo-ymc",
209 },
210 .id_table = lenovo_ymc_wmi_id_table,
211 .probe = lenovo_ymc_probe,
212 .notify = lenovo_ymc_notify,
213 };
214
215 module_wmi_driver(lenovo_ymc_driver);
216
217 MODULE_AUTHOR("Gergo Koteles <soyer@irl.hu>");
218 MODULE_DESCRIPTION("Lenovo Yoga Mode Control driver");
219 MODULE_LICENSE("GPL");
220