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4ab6174e SG |
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/interrupt.h> | |
21 | #include <linux/slab.h> | |
5ebeaff5 | 22 | #include <linux/module.h> |
4ab6174e SG |
23 | #include <linux/mfd/core.h> |
24 | #include <linux/mfd/cros_ec.h> | |
25 | #include <linux/mfd/cros_ec_commands.h> | |
d86c21fd AB |
26 | #include <linux/delay.h> |
27 | ||
28 | #define EC_COMMAND_RETRIES 50 | |
4ab6174e SG |
29 | |
30 | int cros_ec_prepare_tx(struct cros_ec_device *ec_dev, | |
5d4773e2 | 31 | struct cros_ec_command *msg) |
4ab6174e SG |
32 | { |
33 | uint8_t *out; | |
34 | int csum, i; | |
35 | ||
5d4773e2 | 36 | BUG_ON(msg->outsize > EC_PROTO2_MAX_PARAM_SIZE); |
4ab6174e SG |
37 | out = ec_dev->dout; |
38 | out[0] = EC_CMD_VERSION0 + msg->version; | |
5d4773e2 BR |
39 | out[1] = msg->command; |
40 | out[2] = msg->outsize; | |
4ab6174e | 41 | csum = out[0] + out[1] + out[2]; |
5d4773e2 BR |
42 | for (i = 0; i < msg->outsize; i++) |
43 | csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->outdata[i]; | |
44 | out[EC_MSG_TX_HEADER_BYTES + msg->outsize] = (uint8_t)(csum & 0xff); | |
4ab6174e | 45 | |
5d4773e2 | 46 | return EC_MSG_TX_PROTO_BYTES + msg->outsize; |
4ab6174e | 47 | } |
5ebeaff5 | 48 | EXPORT_SYMBOL(cros_ec_prepare_tx); |
4ab6174e | 49 | |
6db07b63 BR |
50 | int cros_ec_check_result(struct cros_ec_device *ec_dev, |
51 | struct cros_ec_command *msg) | |
52 | { | |
53 | switch (msg->result) { | |
54 | case EC_RES_SUCCESS: | |
55 | return 0; | |
56 | case EC_RES_IN_PROGRESS: | |
57 | dev_dbg(ec_dev->dev, "command 0x%02x in progress\n", | |
58 | msg->command); | |
59 | return -EAGAIN; | |
60 | default: | |
61 | dev_dbg(ec_dev->dev, "command 0x%02x returned %d\n", | |
62 | msg->command, msg->result); | |
63 | return 0; | |
64 | } | |
65 | } | |
66 | EXPORT_SYMBOL(cros_ec_check_result); | |
67 | ||
a6551a76 AB |
68 | int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev, |
69 | struct cros_ec_command *msg) | |
70 | { | |
63427530 AB |
71 | int ret; |
72 | ||
73 | mutex_lock(&ec_dev->lock); | |
74 | ret = ec_dev->cmd_xfer(ec_dev, msg); | |
d86c21fd AB |
75 | if (msg->result == EC_RES_IN_PROGRESS) { |
76 | int i; | |
77 | struct cros_ec_command status_msg; | |
78 | struct ec_response_get_comms_status status; | |
79 | ||
80 | status_msg.version = 0; | |
81 | status_msg.command = EC_CMD_GET_COMMS_STATUS; | |
82 | status_msg.outdata = NULL; | |
83 | status_msg.outsize = 0; | |
84 | status_msg.indata = (uint8_t *)&status; | |
85 | status_msg.insize = sizeof(status); | |
86 | ||
87 | /* | |
88 | * Query the EC's status until it's no longer busy or | |
89 | * we encounter an error. | |
90 | */ | |
91 | for (i = 0; i < EC_COMMAND_RETRIES; i++) { | |
92 | usleep_range(10000, 11000); | |
93 | ||
94 | ret = ec_dev->cmd_xfer(ec_dev, &status_msg); | |
95 | if (ret < 0) | |
96 | break; | |
97 | ||
98 | msg->result = status_msg.result; | |
99 | if (status_msg.result != EC_RES_SUCCESS) | |
100 | break; | |
101 | if (!(status.flags & EC_COMMS_STATUS_PROCESSING)) | |
102 | break; | |
103 | } | |
104 | } | |
63427530 AB |
105 | mutex_unlock(&ec_dev->lock); |
106 | ||
107 | return ret; | |
a6551a76 AB |
108 | } |
109 | EXPORT_SYMBOL(cros_ec_cmd_xfer); | |
110 | ||
5ac98553 | 111 | static const struct mfd_cell cros_devs[] = { |
4ab6174e SG |
112 | { |
113 | .name = "cros-ec-keyb", | |
114 | .id = 1, | |
115 | .of_compatible = "google,cros-ec-keyb", | |
116 | }, | |
9d230c9e DA |
117 | { |
118 | .name = "cros-ec-i2c-tunnel", | |
119 | .id = 2, | |
120 | .of_compatible = "google,cros-ec-i2c-tunnel", | |
121 | }, | |
4ab6174e SG |
122 | }; |
123 | ||
124 | int cros_ec_register(struct cros_ec_device *ec_dev) | |
125 | { | |
126 | struct device *dev = ec_dev->dev; | |
127 | int err = 0; | |
128 | ||
4ab6174e | 129 | if (ec_dev->din_size) { |
22f9ee75 LJ |
130 | ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL); |
131 | if (!ec_dev->din) | |
132 | return -ENOMEM; | |
4ab6174e SG |
133 | } |
134 | if (ec_dev->dout_size) { | |
22f9ee75 LJ |
135 | ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL); |
136 | if (!ec_dev->dout) | |
137 | return -ENOMEM; | |
4ab6174e SG |
138 | } |
139 | ||
63427530 AB |
140 | mutex_init(&ec_dev->lock); |
141 | ||
4ab6174e SG |
142 | err = mfd_add_devices(dev, 0, cros_devs, |
143 | ARRAY_SIZE(cros_devs), | |
144 | NULL, ec_dev->irq, NULL); | |
145 | if (err) { | |
146 | dev_err(dev, "failed to add mfd devices\n"); | |
d1fd345e | 147 | return err; |
4ab6174e SG |
148 | } |
149 | ||
533cec8f | 150 | dev_info(dev, "Chrome EC device registered\n"); |
4ab6174e SG |
151 | |
152 | return 0; | |
4ab6174e | 153 | } |
5ebeaff5 | 154 | EXPORT_SYMBOL(cros_ec_register); |
4ab6174e SG |
155 | |
156 | int cros_ec_remove(struct cros_ec_device *ec_dev) | |
157 | { | |
158 | mfd_remove_devices(ec_dev->dev); | |
4ab6174e SG |
159 | |
160 | return 0; | |
161 | } | |
5ebeaff5 | 162 | EXPORT_SYMBOL(cros_ec_remove); |
4ab6174e SG |
163 | |
164 | #ifdef CONFIG_PM_SLEEP | |
165 | int cros_ec_suspend(struct cros_ec_device *ec_dev) | |
166 | { | |
167 | struct device *dev = ec_dev->dev; | |
168 | ||
169 | if (device_may_wakeup(dev)) | |
170 | ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq); | |
171 | ||
172 | disable_irq(ec_dev->irq); | |
173 | ec_dev->was_wake_device = ec_dev->wake_enabled; | |
174 | ||
175 | return 0; | |
176 | } | |
5ebeaff5 | 177 | EXPORT_SYMBOL(cros_ec_suspend); |
4ab6174e SG |
178 | |
179 | int cros_ec_resume(struct cros_ec_device *ec_dev) | |
180 | { | |
181 | enable_irq(ec_dev->irq); | |
182 | ||
183 | if (ec_dev->wake_enabled) { | |
184 | disable_irq_wake(ec_dev->irq); | |
185 | ec_dev->wake_enabled = 0; | |
186 | } | |
187 | ||
188 | return 0; | |
189 | } | |
5ebeaff5 SO |
190 | EXPORT_SYMBOL(cros_ec_resume); |
191 | ||
4ab6174e | 192 | #endif |
a865a589 BR |
193 | |
194 | MODULE_LICENSE("GPL"); | |
195 | MODULE_DESCRIPTION("ChromeOS EC core driver"); |