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Simon Glass4ab61742013-02-25 14:08:37 -08001/*
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/interrupt.h>
21#include <linux/slab.h>
Samuel Ortiz5ebeaff2013-03-20 09:46:15 +010022#include <linux/module.h>
Simon Glass4ab61742013-02-25 14:08:37 -080023#include <linux/mfd/core.h>
24#include <linux/mfd/cros_ec.h>
25#include <linux/mfd/cros_ec_commands.h>
26
27int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
28 struct cros_ec_msg *msg)
29{
30 uint8_t *out;
31 int csum, i;
32
33 BUG_ON(msg->out_len > EC_HOST_PARAM_SIZE);
34 out = ec_dev->dout;
35 out[0] = EC_CMD_VERSION0 + msg->version;
36 out[1] = msg->cmd;
37 out[2] = msg->out_len;
38 csum = out[0] + out[1] + out[2];
39 for (i = 0; i < msg->out_len; i++)
40 csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->out_buf[i];
41 out[EC_MSG_TX_HEADER_BYTES + msg->out_len] = (uint8_t)(csum & 0xff);
42
43 return EC_MSG_TX_PROTO_BYTES + msg->out_len;
44}
Samuel Ortiz5ebeaff2013-03-20 09:46:15 +010045EXPORT_SYMBOL(cros_ec_prepare_tx);
Simon Glass4ab61742013-02-25 14:08:37 -080046
47static int cros_ec_command_sendrecv(struct cros_ec_device *ec_dev,
48 uint16_t cmd, void *out_buf, int out_len,
49 void *in_buf, int in_len)
50{
51 struct cros_ec_msg msg;
52
53 msg.version = cmd >> 8;
54 msg.cmd = cmd & 0xff;
55 msg.out_buf = out_buf;
56 msg.out_len = out_len;
57 msg.in_buf = in_buf;
58 msg.in_len = in_len;
59
60 return ec_dev->command_xfer(ec_dev, &msg);
61}
62
63static int cros_ec_command_recv(struct cros_ec_device *ec_dev,
64 uint16_t cmd, void *buf, int buf_len)
65{
66 return cros_ec_command_sendrecv(ec_dev, cmd, NULL, 0, buf, buf_len);
67}
68
69static int cros_ec_command_send(struct cros_ec_device *ec_dev,
70 uint16_t cmd, void *buf, int buf_len)
71{
72 return cros_ec_command_sendrecv(ec_dev, cmd, buf, buf_len, NULL, 0);
73}
74
75static irqreturn_t ec_irq_thread(int irq, void *data)
76{
77 struct cros_ec_device *ec_dev = data;
78
79 if (device_may_wakeup(ec_dev->dev))
80 pm_wakeup_event(ec_dev->dev, 0);
81
82 blocking_notifier_call_chain(&ec_dev->event_notifier, 1, ec_dev);
83
84 return IRQ_HANDLED;
85}
86
87static struct mfd_cell cros_devs[] = {
88 {
89 .name = "cros-ec-keyb",
90 .id = 1,
91 .of_compatible = "google,cros-ec-keyb",
92 },
93};
94
95int cros_ec_register(struct cros_ec_device *ec_dev)
96{
97 struct device *dev = ec_dev->dev;
98 int err = 0;
99
100 BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);
101
102 ec_dev->command_send = cros_ec_command_send;
103 ec_dev->command_recv = cros_ec_command_recv;
104 ec_dev->command_sendrecv = cros_ec_command_sendrecv;
105
106 if (ec_dev->din_size) {
Lee Jones22f9ee72013-05-23 16:25:10 +0100107 ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
108 if (!ec_dev->din)
109 return -ENOMEM;
Simon Glass4ab61742013-02-25 14:08:37 -0800110 }
111 if (ec_dev->dout_size) {
Lee Jones22f9ee72013-05-23 16:25:10 +0100112 ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
113 if (!ec_dev->dout)
114 return -ENOMEM;
Simon Glass4ab61742013-02-25 14:08:37 -0800115 }
116
117 if (!ec_dev->irq) {
118 dev_dbg(dev, "no valid IRQ: %d\n", ec_dev->irq);
Lee Jones22f9ee72013-05-23 16:25:10 +0100119 return err;
Simon Glass4ab61742013-02-25 14:08:37 -0800120 }
121
122 err = request_threaded_irq(ec_dev->irq, NULL, ec_irq_thread,
123 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
124 "chromeos-ec", ec_dev);
125 if (err) {
126 dev_err(dev, "request irq %d: error %d\n", ec_dev->irq, err);
Lee Jones22f9ee72013-05-23 16:25:10 +0100127 return err;
Simon Glass4ab61742013-02-25 14:08:37 -0800128 }
129
130 err = mfd_add_devices(dev, 0, cros_devs,
131 ARRAY_SIZE(cros_devs),
132 NULL, ec_dev->irq, NULL);
133 if (err) {
134 dev_err(dev, "failed to add mfd devices\n");
135 goto fail_mfd;
136 }
137
138 dev_info(dev, "Chrome EC (%s)\n", ec_dev->name);
139
140 return 0;
141
142fail_mfd:
143 free_irq(ec_dev->irq, ec_dev);
Lee Jones22f9ee72013-05-23 16:25:10 +0100144
Simon Glass4ab61742013-02-25 14:08:37 -0800145 return err;
146}
Samuel Ortiz5ebeaff2013-03-20 09:46:15 +0100147EXPORT_SYMBOL(cros_ec_register);
Simon Glass4ab61742013-02-25 14:08:37 -0800148
149int cros_ec_remove(struct cros_ec_device *ec_dev)
150{
151 mfd_remove_devices(ec_dev->dev);
152 free_irq(ec_dev->irq, ec_dev);
Simon Glass4ab61742013-02-25 14:08:37 -0800153
154 return 0;
155}
Samuel Ortiz5ebeaff2013-03-20 09:46:15 +0100156EXPORT_SYMBOL(cros_ec_remove);
Simon Glass4ab61742013-02-25 14:08:37 -0800157
158#ifdef CONFIG_PM_SLEEP
159int cros_ec_suspend(struct cros_ec_device *ec_dev)
160{
161 struct device *dev = ec_dev->dev;
162
163 if (device_may_wakeup(dev))
164 ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
165
166 disable_irq(ec_dev->irq);
167 ec_dev->was_wake_device = ec_dev->wake_enabled;
168
169 return 0;
170}
Samuel Ortiz5ebeaff2013-03-20 09:46:15 +0100171EXPORT_SYMBOL(cros_ec_suspend);
Simon Glass4ab61742013-02-25 14:08:37 -0800172
173int cros_ec_resume(struct cros_ec_device *ec_dev)
174{
175 enable_irq(ec_dev->irq);
176
177 if (ec_dev->wake_enabled) {
178 disable_irq_wake(ec_dev->irq);
179 ec_dev->wake_enabled = 0;
180 }
181
182 return 0;
183}
Samuel Ortiz5ebeaff2013-03-20 09:46:15 +0100184EXPORT_SYMBOL(cros_ec_resume);
185
Simon Glass4ab61742013-02-25 14:08:37 -0800186#endif