tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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#include <linux/suspend.h>
27#include <asm/unaligned.h>
28
29#define CROS_EC_DEV_EC_INDEX 0
30#define CROS_EC_DEV_PD_INDEX 1
31
32static struct cros_ec_platform ec_p = {
33 .ec_name = CROS_EC_DEV_NAME,
34 .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX),
35};
36
37static struct cros_ec_platform pd_p = {
38 .ec_name = CROS_EC_DEV_PD_NAME,
39 .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX),
40};
41
42static const struct mfd_cell ec_cell = {
43 .name = "cros-ec-dev",
44 .platform_data = &ec_p,
45 .pdata_size = sizeof(ec_p),
46};
47
48static const struct mfd_cell ec_pd_cell = {
49 .name = "cros-ec-dev",
50 .platform_data = &pd_p,
51 .pdata_size = sizeof(pd_p),
52};
53
54static irqreturn_t ec_irq_thread(int irq, void *data)
55{
56 struct cros_ec_device *ec_dev = data;
57 bool wake_event = true;
58 int ret;
59
60 ret = cros_ec_get_next_event(ec_dev, &wake_event);
61
62 /*
63 * Signal only if wake host events or any interrupt if
64 * cros_ec_get_next_event() returned an error (default value for
65 * wake_event is true)
66 */
67 if (wake_event && device_may_wakeup(ec_dev->dev))
68 pm_wakeup_event(ec_dev->dev, 0);
69
70 if (ret > 0)
71 blocking_notifier_call_chain(&ec_dev->event_notifier,
72 0, ec_dev);
73 return IRQ_HANDLED;
74}
75
76static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event)
77{
78 struct {
79 struct cros_ec_command msg;
80 struct ec_params_host_sleep_event req;
81 } __packed buf;
82
83 memset(&buf, 0, sizeof(buf));
84
85 buf.req.sleep_event = sleep_event;
86
87 buf.msg.command = EC_CMD_HOST_SLEEP_EVENT;
88 buf.msg.version = 0;
89 buf.msg.outsize = sizeof(buf.req);
90
91 return cros_ec_cmd_xfer(ec_dev, &buf.msg);
92}
93
94int cros_ec_register(struct cros_ec_device *ec_dev)
95{
96 struct device *dev = ec_dev->dev;
97 int err = 0;
98
99 BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);
100
101 ec_dev->max_request = sizeof(struct ec_params_hello);
102 ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
103 ec_dev->max_passthru = 0;
104
105 ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
106 if (!ec_dev->din)
107 return -ENOMEM;
108
109 ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
110 if (!ec_dev->dout)
111 return -ENOMEM;
112
113 mutex_init(&ec_dev->lock);
114
115 err = cros_ec_query_all(ec_dev);
116 if (err) {
117 dev_err(dev, "Cannot identify the EC: error %d\n", err);
118 return err;
119 }
120
121 if (ec_dev->irq) {
122 err = devm_request_threaded_irq(dev, ec_dev->irq, NULL,
123 ec_irq_thread, IRQF_TRIGGER_LOW | IRQF_ONESHOT,
124 "chromeos-ec", ec_dev);
125 if (err) {
126 dev_err(dev, "Failed to request IRQ %d: %d",
127 ec_dev->irq, err);
128 return err;
129 }
130 }
131
132 err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO, &ec_cell, 1,
133 NULL, ec_dev->irq, NULL);
134 if (err) {
135 dev_err(dev,
136 "Failed to register Embedded Controller subdevice %d\n",
137 err);
138 return err;
139 }
140
141 if (ec_dev->max_passthru) {
142 /*
143 * Register a PD device as well on top of this device.
144 * We make the following assumptions:
145 * - behind an EC, we have a pd
146 * - only one device added.
147 * - the EC is responsive at init time (it is not true for a
148 * sensor hub.
149 */
150 err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO,
151 &ec_pd_cell, 1, NULL, ec_dev->irq, NULL);
152 if (err) {
153 dev_err(dev,
154 "Failed to register Power Delivery subdevice %d\n",
155 err);
156 return err;
157 }
158 }
159
160 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
161 err = devm_of_platform_populate(dev);
162 if (err) {
163 mfd_remove_devices(dev);
164 dev_err(dev, "Failed to register sub-devices\n");
165 return err;
166 }
167 }
168
169 /*
170 * Clear sleep event - this will fail harmlessly on platforms that
171 * don't implement the sleep event host command.
172 */
173 err = cros_ec_sleep_event(ec_dev, 0);
174 if (err < 0)
175 dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec",
176 err);
177
178 dev_info(dev, "Chrome EC device registered\n");
179
180 return 0;
181}
182EXPORT_SYMBOL(cros_ec_register);
183
184int cros_ec_remove(struct cros_ec_device *ec_dev)
185{
186 mfd_remove_devices(ec_dev->dev);
187
188 return 0;
189}
190EXPORT_SYMBOL(cros_ec_remove);
191
192#ifdef CONFIG_PM_SLEEP
193int cros_ec_suspend(struct cros_ec_device *ec_dev)
194{
195 struct device *dev = ec_dev->dev;
196 int ret;
197 u8 sleep_event;
198
199 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ?
200 HOST_SLEEP_EVENT_S3_SUSPEND :
201 HOST_SLEEP_EVENT_S0IX_SUSPEND;
202
203 ret = cros_ec_sleep_event(ec_dev, sleep_event);
204 if (ret < 0)
205 dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec",
206 ret);
207
208 if (device_may_wakeup(dev))
209 ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
210
211 disable_irq(ec_dev->irq);
212 ec_dev->was_wake_device = ec_dev->wake_enabled;
213 ec_dev->suspended = true;
214
215 return 0;
216}
217EXPORT_SYMBOL(cros_ec_suspend);
218
219static void cros_ec_report_events_during_suspend(struct cros_ec_device *ec_dev)
220{
221 while (cros_ec_get_next_event(ec_dev, NULL) > 0)
222 blocking_notifier_call_chain(&ec_dev->event_notifier,
223 1, ec_dev);
224}
225
226int cros_ec_resume(struct cros_ec_device *ec_dev)
227{
228 int ret;
229 u8 sleep_event;
230
231 ec_dev->suspended = false;
232 enable_irq(ec_dev->irq);
233
234 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ?
235 HOST_SLEEP_EVENT_S3_RESUME :
236 HOST_SLEEP_EVENT_S0IX_RESUME;
237
238 ret = cros_ec_sleep_event(ec_dev, sleep_event);
239 if (ret < 0)
240 dev_dbg(ec_dev->dev, "Error %d sending resume event to ec",
241 ret);
242
243 if (ec_dev->wake_enabled) {
244 disable_irq_wake(ec_dev->irq);
245 ec_dev->wake_enabled = 0;
246 }
247 /*
248 * Let the mfd devices know about events that occur during
249 * suspend. This way the clients know what to do with them.
250 */
251 cros_ec_report_events_during_suspend(ec_dev);
252
253
254 return 0;
255}
256EXPORT_SYMBOL(cros_ec_resume);
257
258#endif
259
260MODULE_LICENSE("GPL");
261MODULE_DESCRIPTION("ChromeOS EC core driver");