1/*
2 * ChromeOS EC multi-function device
3 *
4 * Copyright (C) 2012 Google, Inc
5 *
6 * This software is licensed under the terms of the GNU General Public
7 * License version 2, as published by the Free Software Foundation, and
8 * may be copied, distributed, and modified under those terms.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 * GNU General Public License for more details.
14 *
15 * The ChromeOS EC multi function device is used to mux all the requests
16 * to the EC device for its multiple features: keyboard controller,
17 * battery charging and regulator control, firmware update.
18 */
19
20#include <linux/of_platform.h>
21#include <linux/interrupt.h>
22#include <linux/slab.h>
23#include <linux/module.h>
24#include <linux/mfd/core.h>
25#include <linux/mfd/cros_ec.h>
26
27#define CROS_EC_DEV_EC_INDEX 0
28#define CROS_EC_DEV_PD_INDEX 1
29
30static struct cros_ec_platform ec_p = {
31	.ec_name = CROS_EC_DEV_NAME,
32	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX),
33};
34
35static struct cros_ec_platform pd_p = {
36	.ec_name = CROS_EC_DEV_PD_NAME,
37	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX),
38};
39
40static const struct mfd_cell ec_cell = {
41	.name = "cros-ec-ctl",
42	.platform_data = &ec_p,
43	.pdata_size = sizeof(ec_p),
44};
45
46static const struct mfd_cell ec_pd_cell = {
47	.name = "cros-ec-ctl",
48	.platform_data = &pd_p,
49	.pdata_size = sizeof(pd_p),
50};
51
52int cros_ec_register(struct cros_ec_device *ec_dev)
53{
54	struct device *dev = ec_dev->dev;
55	int err = 0;
56
57	ec_dev->max_request = sizeof(struct ec_params_hello);
58	ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
59	ec_dev->max_passthru = 0;
60
61	ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
62	if (!ec_dev->din)
63		return -ENOMEM;
64
65	ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
66	if (!ec_dev->dout)
67		return -ENOMEM;
68
69	mutex_init(&ec_dev->lock);
70
71	cros_ec_query_all(ec_dev);
72
73	err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO, &ec_cell, 1,
74			      NULL, ec_dev->irq, NULL);
75	if (err) {
76		dev_err(dev,
77			"Failed to register Embedded Controller subdevice %d\n",
78			err);
79		return err;
80	}
81
82	if (ec_dev->max_passthru) {
83		/*
84		 * Register a PD device as well on top of this device.
85		 * We make the following assumptions:
86		 * - behind an EC, we have a pd
87		 * - only one device added.
88		 * - the EC is responsive at init time (it is not true for a
89		 *   sensor hub.
90		 */
91		err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO,
92				      &ec_pd_cell, 1, NULL, ec_dev->irq, NULL);
93		if (err) {
94			dev_err(dev,
95				"Failed to register Power Delivery subdevice %d\n",
96				err);
97			return err;
98		}
99	}
100
101	if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
102		err = of_platform_populate(dev->of_node, NULL, NULL, dev);
103		if (err) {
104			mfd_remove_devices(dev);
105			dev_err(dev, "Failed to register sub-devices\n");
106			return err;
107		}
108	}
109
110	dev_info(dev, "Chrome EC device registered\n");
111
112	return 0;
113}
114EXPORT_SYMBOL(cros_ec_register);
115
116int cros_ec_remove(struct cros_ec_device *ec_dev)
117{
118	mfd_remove_devices(ec_dev->dev);
119
120	return 0;
121}
122EXPORT_SYMBOL(cros_ec_remove);
123
124#ifdef CONFIG_PM_SLEEP
125int cros_ec_suspend(struct cros_ec_device *ec_dev)
126{
127	struct device *dev = ec_dev->dev;
128
129	if (device_may_wakeup(dev))
130		ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
131
132	disable_irq(ec_dev->irq);
133	ec_dev->was_wake_device = ec_dev->wake_enabled;
134
135	return 0;
136}
137EXPORT_SYMBOL(cros_ec_suspend);
138
139int cros_ec_resume(struct cros_ec_device *ec_dev)
140{
141	enable_irq(ec_dev->irq);
142
143	if (ec_dev->wake_enabled) {
144		disable_irq_wake(ec_dev->irq);
145		ec_dev->wake_enabled = 0;
146	}
147
148	return 0;
149}
150EXPORT_SYMBOL(cros_ec_resume);
151
152#endif
153
154MODULE_LICENSE("GPL");
155MODULE_DESCRIPTION("ChromeOS EC core driver");
156