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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * ChromeOS EC multi-function device
4 *
5 * Copyright (C) 2012 Google, Inc
6 *
7 * The ChromeOS EC multi function device is used to mux all the requests
8 * to the EC device for its multiple features: keyboard controller,
9 * battery charging and regulator control, firmware update.
10 */
11
12#include <linux/of_platform.h>
13#include <linux/interrupt.h>
14#include <linux/slab.h>
15#include <linux/module.h>
16#include <linux/platform_data/cros_ec_commands.h>
17#include <linux/platform_data/cros_ec_proto.h>
18#include <linux/suspend.h>
19
20#include "cros_ec.h"
21
22#define CROS_EC_DEV_EC_INDEX 0
23#define CROS_EC_DEV_PD_INDEX 1
24
25static struct cros_ec_platform ec_p = {
26 .ec_name = CROS_EC_DEV_NAME,
27 .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX),
28};
29
30static struct cros_ec_platform pd_p = {
31 .ec_name = CROS_EC_DEV_PD_NAME,
32 .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX),
33};
34
35/**
36 * cros_ec_irq_handler() - top half part of the interrupt handler
37 * @irq: IRQ id
38 * @data: (ec_dev) Device with events to process.
39 *
40 * Return: Wakeup the bottom half
41 */
42static irqreturn_t cros_ec_irq_handler(int irq, void *data)
43{
44 struct cros_ec_device *ec_dev = data;
45
46 ec_dev->last_event_time = cros_ec_get_time_ns();
47
48 return IRQ_WAKE_THREAD;
49}
50
51/**
52 * cros_ec_handle_event() - process and forward pending events on EC
53 * @ec_dev: Device with events to process.
54 *
55 * Call this function in a loop when the kernel is notified that the EC has
56 * pending events.
57 *
58 * Return: true if more events are still pending and this function should be
59 * called again.
60 */
61static bool cros_ec_handle_event(struct cros_ec_device *ec_dev)
62{
63 bool wake_event;
64 bool ec_has_more_events;
65 int ret;
66
67 ret = cros_ec_get_next_event(ec_dev, &wake_event, &ec_has_more_events);
68
69 /*
70 * Signal only if wake host events or any interrupt if
71 * cros_ec_get_next_event() returned an error (default value for
72 * wake_event is true)
73 */
74 if (wake_event && device_may_wakeup(ec_dev->dev))
75 pm_wakeup_event(ec_dev->dev, 0);
76
77 if (ret > 0)
78 blocking_notifier_call_chain(&ec_dev->event_notifier,
79 0, ec_dev);
80
81 return ec_has_more_events;
82}
83
84/**
85 * cros_ec_irq_thread() - bottom half part of the interrupt handler
86 * @irq: IRQ id
87 * @data: (ec_dev) Device with events to process.
88 *
89 * Return: Interrupt handled.
90 */
91irqreturn_t cros_ec_irq_thread(int irq, void *data)
92{
93 struct cros_ec_device *ec_dev = data;
94 bool ec_has_more_events;
95
96 do {
97 ec_has_more_events = cros_ec_handle_event(ec_dev);
98 } while (ec_has_more_events);
99
100 return IRQ_HANDLED;
101}
102EXPORT_SYMBOL(cros_ec_irq_thread);
103
104static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event)
105{
106 int ret;
107 struct {
108 struct cros_ec_command msg;
109 union {
110 struct ec_params_host_sleep_event req0;
111 struct ec_params_host_sleep_event_v1 req1;
112 struct ec_response_host_sleep_event_v1 resp1;
113 } u;
114 } __packed buf;
115
116 memset(&buf, 0, sizeof(buf));
117
118 if (ec_dev->host_sleep_v1) {
119 buf.u.req1.sleep_event = sleep_event;
120 buf.u.req1.suspend_params.sleep_timeout_ms =
121 EC_HOST_SLEEP_TIMEOUT_DEFAULT;
122
123 buf.msg.outsize = sizeof(buf.u.req1);
124 if ((sleep_event == HOST_SLEEP_EVENT_S3_RESUME) ||
125 (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME))
126 buf.msg.insize = sizeof(buf.u.resp1);
127
128 buf.msg.version = 1;
129
130 } else {
131 buf.u.req0.sleep_event = sleep_event;
132 buf.msg.outsize = sizeof(buf.u.req0);
133 }
134
135 buf.msg.command = EC_CMD_HOST_SLEEP_EVENT;
136
137 ret = cros_ec_cmd_xfer_status(ec_dev, &buf.msg);
138
139 /* For now, report failure to transition to S0ix with a warning. */
140 if (ret >= 0 && ec_dev->host_sleep_v1 &&
141 (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME)) {
142 ec_dev->last_resume_result =
143 buf.u.resp1.resume_response.sleep_transitions;
144
145 WARN_ONCE(buf.u.resp1.resume_response.sleep_transitions &
146 EC_HOST_RESUME_SLEEP_TIMEOUT,
147 "EC detected sleep transition timeout. Total slp_s0 transitions: %d",
148 buf.u.resp1.resume_response.sleep_transitions &
149 EC_HOST_RESUME_SLEEP_TRANSITIONS_MASK);
150 }
151
152 return ret;
153}
154
155static int cros_ec_ready_event(struct notifier_block *nb,
156 unsigned long queued_during_suspend,
157 void *_notify)
158{
159 struct cros_ec_device *ec_dev = container_of(nb, struct cros_ec_device,
160 notifier_ready);
161 u32 host_event = cros_ec_get_host_event(ec_dev);
162
163 if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_INTERFACE_READY)) {
164 mutex_lock(&ec_dev->lock);
165 cros_ec_query_all(ec_dev);
166 mutex_unlock(&ec_dev->lock);
167 return NOTIFY_OK;
168 }
169
170 return NOTIFY_DONE;
171}
172
173/**
174 * cros_ec_register() - Register a new ChromeOS EC, using the provided info.
175 * @ec_dev: Device to register.
176 *
177 * Before calling this, allocate a pointer to a new device and then fill
178 * in all the fields up to the --private-- marker.
179 *
180 * Return: 0 on success or negative error code.
181 */
182int cros_ec_register(struct cros_ec_device *ec_dev)
183{
184 struct device *dev = ec_dev->dev;
185 int err = 0;
186
187 BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);
188
189 ec_dev->max_request = sizeof(struct ec_params_hello);
190 ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
191 ec_dev->max_passthru = 0;
192
193 ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
194 if (!ec_dev->din)
195 return -ENOMEM;
196
197 ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
198 if (!ec_dev->dout)
199 return -ENOMEM;
200
201 mutex_init(&ec_dev->lock);
202
203 err = cros_ec_query_all(ec_dev);
204 if (err) {
205 dev_err(dev, "Cannot identify the EC: error %d\n", err);
206 return err;
207 }
208
209 if (ec_dev->irq > 0) {
210 err = devm_request_threaded_irq(dev, ec_dev->irq,
211 cros_ec_irq_handler,
212 cros_ec_irq_thread,
213 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
214 "chromeos-ec", ec_dev);
215 if (err) {
216 dev_err(dev, "Failed to request IRQ %d: %d",
217 ec_dev->irq, err);
218 return err;
219 }
220 }
221
222 /* Register a platform device for the main EC instance */
223 ec_dev->ec = platform_device_register_data(ec_dev->dev, "cros-ec-dev",
224 PLATFORM_DEVID_AUTO, &ec_p,
225 sizeof(struct cros_ec_platform));
226 if (IS_ERR(ec_dev->ec)) {
227 dev_err(ec_dev->dev,
228 "Failed to create CrOS EC platform device\n");
229 return PTR_ERR(ec_dev->ec);
230 }
231
232 if (ec_dev->max_passthru) {
233 /*
234 * Register a platform device for the PD behind the main EC.
235 * We make the following assumptions:
236 * - behind an EC, we have a pd
237 * - only one device added.
238 * - the EC is responsive at init time (it is not true for a
239 * sensor hub).
240 */
241 ec_dev->pd = platform_device_register_data(ec_dev->dev,
242 "cros-ec-dev",
243 PLATFORM_DEVID_AUTO, &pd_p,
244 sizeof(struct cros_ec_platform));
245 if (IS_ERR(ec_dev->pd)) {
246 dev_err(ec_dev->dev,
247 "Failed to create CrOS PD platform device\n");
248 platform_device_unregister(ec_dev->ec);
249 return PTR_ERR(ec_dev->pd);
250 }
251 }
252
253 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
254 err = devm_of_platform_populate(dev);
255 if (err) {
256 platform_device_unregister(ec_dev->pd);
257 platform_device_unregister(ec_dev->ec);
258 dev_err(dev, "Failed to register sub-devices\n");
259 return err;
260 }
261 }
262
263 /*
264 * Clear sleep event - this will fail harmlessly on platforms that
265 * don't implement the sleep event host command.
266 */
267 err = cros_ec_sleep_event(ec_dev, 0);
268 if (err < 0)
269 dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec",
270 err);
271
272 if (ec_dev->mkbp_event_supported) {
273 /*
274 * Register the notifier for EC_HOST_EVENT_INTERFACE_READY
275 * event.
276 */
277 ec_dev->notifier_ready.notifier_call = cros_ec_ready_event;
278 err = blocking_notifier_chain_register(&ec_dev->event_notifier,
279 &ec_dev->notifier_ready);
280 if (err)
281 return err;
282 }
283
284 dev_info(dev, "Chrome EC device registered\n");
285
286 /*
287 * Unlock EC that may be waiting for AP to process MKBP events.
288 * If the AP takes to long to answer, the EC would stop sending events.
289 */
290 if (ec_dev->mkbp_event_supported)
291 cros_ec_irq_thread(0, ec_dev);
292
293 return 0;
294}
295EXPORT_SYMBOL(cros_ec_register);
296
297/**
298 * cros_ec_unregister() - Remove a ChromeOS EC.
299 * @ec_dev: Device to unregister.
300 *
301 * Call this to deregister a ChromeOS EC, then clean up any private data.
302 *
303 * Return: 0 on success or negative error code.
304 */
305int cros_ec_unregister(struct cros_ec_device *ec_dev)
306{
307 if (ec_dev->pd)
308 platform_device_unregister(ec_dev->pd);
309 platform_device_unregister(ec_dev->ec);
310
311 return 0;
312}
313EXPORT_SYMBOL(cros_ec_unregister);
314
315#ifdef CONFIG_PM_SLEEP
316/**
317 * cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device.
318 * @ec_dev: Device to suspend.
319 *
320 * This can be called by drivers to handle a suspend event.
321 *
322 * Return: 0 on success or negative error code.
323 */
324int cros_ec_suspend(struct cros_ec_device *ec_dev)
325{
326 struct device *dev = ec_dev->dev;
327 int ret;
328 u8 sleep_event;
329
330 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ?
331 HOST_SLEEP_EVENT_S3_SUSPEND :
332 HOST_SLEEP_EVENT_S0IX_SUSPEND;
333
334 ret = cros_ec_sleep_event(ec_dev, sleep_event);
335 if (ret < 0)
336 dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec",
337 ret);
338
339 if (device_may_wakeup(dev))
340 ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
341
342 disable_irq(ec_dev->irq);
343 ec_dev->was_wake_device = ec_dev->wake_enabled;
344 ec_dev->suspended = true;
345
346 return 0;
347}
348EXPORT_SYMBOL(cros_ec_suspend);
349
350static void cros_ec_report_events_during_suspend(struct cros_ec_device *ec_dev)
351{
352 while (ec_dev->mkbp_event_supported &&
353 cros_ec_get_next_event(ec_dev, NULL, NULL) > 0)
354 blocking_notifier_call_chain(&ec_dev->event_notifier,
355 1, ec_dev);
356}
357
358/**
359 * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device.
360 * @ec_dev: Device to resume.
361 *
362 * This can be called by drivers to handle a resume event.
363 *
364 * Return: 0 on success or negative error code.
365 */
366int cros_ec_resume(struct cros_ec_device *ec_dev)
367{
368 int ret;
369 u8 sleep_event;
370
371 ec_dev->suspended = false;
372 enable_irq(ec_dev->irq);
373
374 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ?
375 HOST_SLEEP_EVENT_S3_RESUME :
376 HOST_SLEEP_EVENT_S0IX_RESUME;
377
378 ret = cros_ec_sleep_event(ec_dev, sleep_event);
379 if (ret < 0)
380 dev_dbg(ec_dev->dev, "Error %d sending resume event to ec",
381 ret);
382
383 if (ec_dev->wake_enabled) {
384 disable_irq_wake(ec_dev->irq);
385 ec_dev->wake_enabled = 0;
386 }
387 /*
388 * Let the mfd devices know about events that occur during
389 * suspend. This way the clients know what to do with them.
390 */
391 cros_ec_report_events_during_suspend(ec_dev);
392
393
394 return 0;
395}
396EXPORT_SYMBOL(cros_ec_resume);
397
398#endif
399
400MODULE_LICENSE("GPL");
401MODULE_DESCRIPTION("ChromeOS EC core driver");