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
 23static bool ec_trigger __read_mostly;
 24module_param(ec_trigger, bool, 0444);
 25MODULE_PARM_DESC(ec_trigger, "Enable EC triggering work-around to force emitting tablet mode events");
 26
 27static bool force;
 28module_param(force, bool, 0444);
 29MODULE_PARM_DESC(force, "Force loading on boards without a convertible DMI chassis-type");
 30
 31static 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
 49static 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
 63struct lenovo_ymc_private {
 64	struct input_dev *input_dev;
 65	struct acpi_device *ec_acpi_dev;
 66};
 67
 68static 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
 80static 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
 92static 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
126free_obj:
127	kfree(obj);
128	lenovo_ymc_trigger_ec(wdev, priv);
129}
130
131static void acpi_dev_put_helper(void *p) { acpi_dev_put(p); }
132
133static 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
200static const struct wmi_device_id lenovo_ymc_wmi_id_table[] = {
201	{ .guid_string = LENOVO_YMC_EVENT_GUID },
202	{ }
203};
204MODULE_DEVICE_TABLE(wmi, lenovo_ymc_wmi_id_table);
205
206static 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
215module_wmi_driver(lenovo_ymc_driver);
216
217MODULE_AUTHOR("Gergo Koteles <soyer@irl.hu>");
218MODULE_DESCRIPTION("Lenovo Yoga Mode Control driver");
219MODULE_LICENSE("GPL");