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
30 static 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
35 static 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
40 static const struct mfd_cell ec_cell = {
41 .name = "cros-ec-ctl",
42 .platform_data = &ec_p,
43 .pdata_size = sizeof(ec_p),
44 };
45
46 static 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
cros_ec_register(struct cros_ec_device * ec_dev)52 int 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 err = cros_ec_query_all(ec_dev);
72 if (err) {
73 dev_err(dev, "Cannot identify the EC: error %d\n", err);
74 return err;
75 }
76
77 err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO, &ec_cell, 1,
78 NULL, ec_dev->irq, NULL);
79 if (err) {
80 dev_err(dev,
81 "Failed to register Embedded Controller subdevice %d\n",
82 err);
83 return err;
84 }
85
86 if (ec_dev->max_passthru) {
87 /*
88 * Register a PD device as well on top of this device.
89 * We make the following assumptions:
90 * - behind an EC, we have a pd
91 * - only one device added.
92 * - the EC is responsive at init time (it is not true for a
93 * sensor hub.
94 */
95 err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO,
96 &ec_pd_cell, 1, NULL, ec_dev->irq, NULL);
97 if (err) {
98 dev_err(dev,
99 "Failed to register Power Delivery subdevice %d\n",
100 err);
101 return err;
102 }
103 }
104
105 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
106 err = of_platform_populate(dev->of_node, NULL, NULL, dev);
107 if (err) {
108 mfd_remove_devices(dev);
109 dev_err(dev, "Failed to register sub-devices\n");
110 return err;
111 }
112 }
113
114 dev_info(dev, "Chrome EC device registered\n");
115
116 return 0;
117 }
118 EXPORT_SYMBOL(cros_ec_register);
119
cros_ec_remove(struct cros_ec_device * ec_dev)120 int cros_ec_remove(struct cros_ec_device *ec_dev)
121 {
122 mfd_remove_devices(ec_dev->dev);
123
124 return 0;
125 }
126 EXPORT_SYMBOL(cros_ec_remove);
127
128 #ifdef CONFIG_PM_SLEEP
cros_ec_suspend(struct cros_ec_device * ec_dev)129 int cros_ec_suspend(struct cros_ec_device *ec_dev)
130 {
131 struct device *dev = ec_dev->dev;
132
133 if (device_may_wakeup(dev))
134 ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
135
136 disable_irq(ec_dev->irq);
137 ec_dev->was_wake_device = ec_dev->wake_enabled;
138
139 return 0;
140 }
141 EXPORT_SYMBOL(cros_ec_suspend);
142
cros_ec_resume(struct cros_ec_device * ec_dev)143 int cros_ec_resume(struct cros_ec_device *ec_dev)
144 {
145 enable_irq(ec_dev->irq);
146
147 if (ec_dev->wake_enabled) {
148 disable_irq_wake(ec_dev->irq);
149 ec_dev->wake_enabled = 0;
150 }
151
152 return 0;
153 }
154 EXPORT_SYMBOL(cros_ec_resume);
155
156 #endif
157
158 MODULE_LICENSE("GPL");
159 MODULE_DESCRIPTION("ChromeOS EC core driver");
160