aboutsummaryrefslogtreecommitdiff
path: root/drivers/mfd/cros_ec.c
blob: 783fe2e73e1edd43344d3bb4c3b1fb09daf9cf3d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
/*
 * ChromeOS EC multi-function device
 *
 * Copyright (C) 2012 Google, Inc
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * The ChromeOS EC multi function device is used to mux all the requests
 * to the EC device for its multiple features: keyboard controller,
 * battery charging and regulator control, firmware update.
 */

#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/mfd/core.h>
#include <linux/mfd/cros_ec.h>
#include <linux/mfd/cros_ec_commands.h>

int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
		       struct cros_ec_msg *msg)
{
	uint8_t *out;
	int csum, i;

	BUG_ON(msg->out_len > EC_HOST_PARAM_SIZE);
	out = ec_dev->dout;
	out[0] = EC_CMD_VERSION0 + msg->version;
	out[1] = msg->cmd;
	out[2] = msg->out_len;
	csum = out[0] + out[1] + out[2];
	for (i = 0; i < msg->out_len; i++)
		csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->out_buf[i];
	out[EC_MSG_TX_HEADER_BYTES + msg->out_len] = (uint8_t)(csum & 0xff);

	return EC_MSG_TX_PROTO_BYTES + msg->out_len;
}
EXPORT_SYMBOL(cros_ec_prepare_tx);

static int cros_ec_command_sendrecv(struct cros_ec_device *ec_dev,
		uint16_t cmd, void *out_buf, int out_len,
		void *in_buf, int in_len)
{
	struct cros_ec_msg msg;

	msg.version = cmd >> 8;
	msg.cmd = cmd & 0xff;
	msg.out_buf = out_buf;
	msg.out_len = out_len;
	msg.in_buf = in_buf;
	msg.in_len = in_len;

	return ec_dev->command_xfer(ec_dev, &msg);
}

static int cros_ec_command_recv(struct cros_ec_device *ec_dev,
		uint16_t cmd, void *buf, int buf_len)
{
	return cros_ec_command_sendrecv(ec_dev, cmd, NULL, 0, buf, buf_len);
}

static int cros_ec_command_send(struct cros_ec_device *ec_dev,
		uint16_t cmd, void *buf, int buf_len)
{
	return cros_ec_command_sendrecv(ec_dev, cmd, buf, buf_len, NULL, 0);
}

static irqreturn_t ec_irq_thread(int irq, void *data)
{
	struct cros_ec_device *ec_dev = data;

	if (device_may_wakeup(ec_dev->dev))
		pm_wakeup_event(ec_dev->dev, 0);

	blocking_notifier_call_chain(&ec_dev->event_notifier, 1, ec_dev);

	return IRQ_HANDLED;
}

static const struct mfd_cell cros_devs[] = {
	{
		.name = "cros-ec-keyb",
		.id = 1,
		.of_compatible = "google,cros-ec-keyb",
	},
};

int cros_ec_register(struct cros_ec_device *ec_dev)
{
	struct device *dev = ec_dev->dev;
	int err = 0;

	BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);

	ec_dev->command_send = cros_ec_command_send;
	ec_dev->command_recv = cros_ec_command_recv;
	ec_dev->command_sendrecv = cros_ec_command_sendrecv;

	if (ec_dev->din_size) {
		ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
		if (!ec_dev->din)
			return -ENOMEM;
	}
	if (ec_dev->dout_size) {
		ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
		if (!ec_dev->dout)
			return -ENOMEM;
	}

	if (!ec_dev->irq) {
		dev_dbg(dev, "no valid IRQ: %d\n", ec_dev->irq);
		return err;
	}

	err = request_threaded_irq(ec_dev->irq, NULL, ec_irq_thread,
				   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
				   "chromeos-ec", ec_dev);
	if (err) {
		dev_err(dev, "request irq %d: error %d\n", ec_dev->irq, err);
		return err;
	}

	err = mfd_add_devices(dev, 0, cros_devs,
			      ARRAY_SIZE(cros_devs),
			      NULL, ec_dev->irq, NULL);
	if (err) {
		dev_err(dev, "failed to add mfd devices\n");
		goto fail_mfd;
	}

	dev_info(dev, "Chrome EC (%s)\n", ec_dev->name);

	return 0;

fail_mfd:
	free_irq(ec_dev->irq, ec_dev);

	return err;
}
EXPORT_SYMBOL(cros_ec_register);

int cros_ec_remove(struct cros_ec_device *ec_dev)
{
	mfd_remove_devices(ec_dev->dev);
	free_irq(ec_dev->irq, ec_dev);

	return 0;
}
EXPORT_SYMBOL(cros_ec_remove);

#ifdef CONFIG_PM_SLEEP
int cros_ec_suspend(struct cros_ec_device *ec_dev)
{
	struct device *dev = ec_dev->dev;

	if (device_may_wakeup(dev))
		ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);

	disable_irq(ec_dev->irq);
	ec_dev->was_wake_device = ec_dev->wake_enabled;

	return 0;
}
EXPORT_SYMBOL(cros_ec_suspend);

int cros_ec_resume(struct cros_ec_device *ec_dev)
{
	enable_irq(ec_dev->irq);

	if (ec_dev->wake_enabled) {
		disable_irq_wake(ec_dev->irq);
		ec_dev->wake_enabled = 0;
	}

	return 0;
}
EXPORT_SYMBOL(cros_ec_resume);

#endif