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/interrupt.h>
21 #include <linux/slab.h>
22 #include <linux/module.h>
23 #include <linux/mfd/core.h>
24 #include <linux/mfd/cros_ec.h>
25 #include <linux/mfd/cros_ec_commands.h>
27 int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
28 struct cros_ec_command *msg)
33 BUG_ON(msg->outsize > EC_PROTO2_MAX_PARAM_SIZE);
35 out[0] = EC_CMD_VERSION0 + msg->version;
36 out[1] = msg->command;
37 out[2] = msg->outsize;
38 csum = out[0] + out[1] + out[2];
39 for (i = 0; i < msg->outsize; i++)
40 csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->outdata[i];
41 out[EC_MSG_TX_HEADER_BYTES + msg->outsize] = (uint8_t)(csum & 0xff);
43 return EC_MSG_TX_PROTO_BYTES + msg->outsize;
45 EXPORT_SYMBOL(cros_ec_prepare_tx);
47 static irqreturn_t ec_irq_thread(int irq, void *data)
49 struct cros_ec_device *ec_dev = data;
51 if (device_may_wakeup(ec_dev->dev))
52 pm_wakeup_event(ec_dev->dev, 0);
54 blocking_notifier_call_chain(&ec_dev->event_notifier, 1, ec_dev);
59 static const struct mfd_cell cros_devs[] = {
61 .name = "cros-ec-keyb",
63 .of_compatible = "google,cros-ec-keyb",
66 .name = "cros-ec-i2c-tunnel",
68 .of_compatible = "google,cros-ec-i2c-tunnel",
72 int cros_ec_register(struct cros_ec_device *ec_dev)
74 struct device *dev = ec_dev->dev;
77 BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);
79 if (ec_dev->din_size) {
80 ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
84 if (ec_dev->dout_size) {
85 ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
91 dev_dbg(dev, "no valid IRQ: %d\n", ec_dev->irq);
95 err = request_threaded_irq(ec_dev->irq, NULL, ec_irq_thread,
96 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
97 "chromeos-ec", ec_dev);
99 dev_err(dev, "request irq %d: error %d\n", ec_dev->irq, err);
103 err = mfd_add_devices(dev, 0, cros_devs,
104 ARRAY_SIZE(cros_devs),
105 NULL, ec_dev->irq, NULL);
107 dev_err(dev, "failed to add mfd devices\n");
111 dev_info(dev, "Chrome EC device registered\n");
116 free_irq(ec_dev->irq, ec_dev);
120 EXPORT_SYMBOL(cros_ec_register);
122 int cros_ec_remove(struct cros_ec_device *ec_dev)
124 mfd_remove_devices(ec_dev->dev);
125 free_irq(ec_dev->irq, ec_dev);
129 EXPORT_SYMBOL(cros_ec_remove);
131 #ifdef CONFIG_PM_SLEEP
132 int cros_ec_suspend(struct cros_ec_device *ec_dev)
134 struct device *dev = ec_dev->dev;
136 if (device_may_wakeup(dev))
137 ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
139 disable_irq(ec_dev->irq);
140 ec_dev->was_wake_device = ec_dev->wake_enabled;
144 EXPORT_SYMBOL(cros_ec_suspend);
146 int cros_ec_resume(struct cros_ec_device *ec_dev)
148 enable_irq(ec_dev->irq);
150 if (ec_dev->wake_enabled) {
151 disable_irq_wake(ec_dev->irq);
152 ec_dev->wake_enabled = 0;
157 EXPORT_SYMBOL(cros_ec_resume);
161 MODULE_LICENSE("GPL");
162 MODULE_DESCRIPTION("ChromeOS EC core driver");