2 * ChromeOS EC multi-function device
4 * Copyright (C) 2012 Google, Inc
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.
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.
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.
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 #include <asm/unaligned.h>
28 #define CROS_EC_DEV_EC_INDEX 0
29 #define CROS_EC_DEV_PD_INDEX 1
31 static struct cros_ec_platform ec_p = {
32 .ec_name = CROS_EC_DEV_NAME,
33 .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX),
36 static struct cros_ec_platform pd_p = {
37 .ec_name = CROS_EC_DEV_PD_NAME,
38 .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX),
41 static const struct mfd_cell ec_cell = {
42 .name = "cros-ec-ctl",
43 .platform_data = &ec_p,
44 .pdata_size = sizeof(ec_p),
47 static const struct mfd_cell ec_pd_cell = {
48 .name = "cros-ec-ctl",
49 .platform_data = &pd_p,
50 .pdata_size = sizeof(pd_p),
53 static irqreturn_t ec_irq_thread(int irq, void *data)
55 struct cros_ec_device *ec_dev = data;
58 if (device_may_wakeup(ec_dev->dev))
59 pm_wakeup_event(ec_dev->dev, 0);
61 ret = cros_ec_get_next_event(ec_dev);
63 blocking_notifier_call_chain(&ec_dev->event_notifier,
68 int cros_ec_register(struct cros_ec_device *ec_dev)
70 struct device *dev = ec_dev->dev;
73 BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);
75 ec_dev->max_request = sizeof(struct ec_params_hello);
76 ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
77 ec_dev->max_passthru = 0;
79 ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
83 ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
87 mutex_init(&ec_dev->lock);
89 err = cros_ec_query_all(ec_dev);
91 dev_err(dev, "Cannot identify the EC: error %d\n", err);
96 err = request_threaded_irq(ec_dev->irq, NULL, ec_irq_thread,
97 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
98 "chromeos-ec", ec_dev);
100 dev_err(dev, "Failed to request IRQ %d: %d",
106 err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO, &ec_cell, 1,
107 NULL, ec_dev->irq, NULL);
110 "Failed to register Embedded Controller subdevice %d\n",
115 if (ec_dev->max_passthru) {
117 * Register a PD device as well on top of this device.
118 * We make the following assumptions:
119 * - behind an EC, we have a pd
120 * - only one device added.
121 * - the EC is responsive at init time (it is not true for a
124 err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO,
125 &ec_pd_cell, 1, NULL, ec_dev->irq, NULL);
128 "Failed to register Power Delivery subdevice %d\n",
134 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
135 err = of_platform_populate(dev->of_node, NULL, NULL, dev);
137 mfd_remove_devices(dev);
138 dev_err(dev, "Failed to register sub-devices\n");
143 dev_info(dev, "Chrome EC device registered\n");
149 free_irq(ec_dev->irq, ec_dev);
152 EXPORT_SYMBOL(cros_ec_register);
154 int cros_ec_remove(struct cros_ec_device *ec_dev)
156 mfd_remove_devices(ec_dev->dev);
160 EXPORT_SYMBOL(cros_ec_remove);
162 #ifdef CONFIG_PM_SLEEP
163 int cros_ec_suspend(struct cros_ec_device *ec_dev)
165 struct device *dev = ec_dev->dev;
167 if (device_may_wakeup(dev))
168 ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
170 disable_irq(ec_dev->irq);
171 ec_dev->was_wake_device = ec_dev->wake_enabled;
175 EXPORT_SYMBOL(cros_ec_suspend);
177 static void cros_ec_drain_events(struct cros_ec_device *ec_dev)
179 while (cros_ec_get_next_event(ec_dev) > 0)
180 blocking_notifier_call_chain(&ec_dev->event_notifier,
184 int cros_ec_resume(struct cros_ec_device *ec_dev)
186 enable_irq(ec_dev->irq);
189 * In some cases, we need to distinguish between events that occur
190 * during suspend if the EC is not a wake source. For example,
191 * keypresses during suspend should be discarded if it does not wake
194 * If the EC is not a wake source, drain the event queue and mark them
195 * as "queued during suspend".
197 if (ec_dev->wake_enabled) {
198 disable_irq_wake(ec_dev->irq);
199 ec_dev->wake_enabled = 0;
201 cros_ec_drain_events(ec_dev);
206 EXPORT_SYMBOL(cros_ec_resume);
210 MODULE_LICENSE("GPL");
211 MODULE_DESCRIPTION("ChromeOS EC core driver");