[linux.git] / drivers / mfd / cros_ec.c

/*
 * ChromeOS EC multi-function device
 *
 * Copyright (C) 2012 Google, Inc
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * The ChromeOS EC multi function device is used to mux all the requests
 * to the EC device for its multiple features: keyboard controller,
 * battery charging and regulator control, firmware update.
 */

#include <linux/of_platform.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/mfd/core.h>
#include <linux/mfd/cros_ec.h>
#include <linux/suspend.h>
#include <asm/unaligned.h>

#define CROS_EC_DEV_EC_INDEX 0
#define CROS_EC_DEV_PD_INDEX 1

static struct cros_ec_platform ec_p = {
	.ec_name = CROS_EC_DEV_NAME,
	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX),
};

static struct cros_ec_platform pd_p = {
	.ec_name = CROS_EC_DEV_PD_NAME,
	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX),
};

static const struct mfd_cell ec_cell = {
	.name = "cros-ec-dev",
	.platform_data = &ec_p,
	.pdata_size = sizeof(ec_p),
};

static const struct mfd_cell ec_pd_cell = {
	.name = "cros-ec-dev",
	.platform_data = &pd_p,
	.pdata_size = sizeof(pd_p),
};

static irqreturn_t ec_irq_thread(int irq, void *data)
{
	struct cros_ec_device *ec_dev = data;
	bool wake_event = true;
	int ret;

	ret = cros_ec_get_next_event(ec_dev, &wake_event);

	/*
	 * Signal only if wake host events or any interrupt if
	 * cros_ec_get_next_event() returned an error (default value for
	 * wake_event is true)
	 */
	if (wake_event && device_may_wakeup(ec_dev->dev))
		pm_wakeup_event(ec_dev->dev, 0);

	if (ret > 0)
		blocking_notifier_call_chain(&ec_dev->event_notifier,
					     0, ec_dev);
	return IRQ_HANDLED;
}

static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event)
{
	struct {
		struct cros_ec_command msg;
		struct ec_params_host_sleep_event req;
	} __packed buf;

	memset(&buf, 0, sizeof(buf));

	buf.req.sleep_event = sleep_event;

	buf.msg.command = EC_CMD_HOST_SLEEP_EVENT;
	buf.msg.version = 0;
	buf.msg.outsize = sizeof(buf.req);

	return cros_ec_cmd_xfer(ec_dev, &buf.msg);
}

int cros_ec_register(struct cros_ec_device *ec_dev)
{
	struct device *dev = ec_dev->dev;
	int err = 0;

	BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);

	ec_dev->max_request = sizeof(struct ec_params_hello);
	ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
	ec_dev->max_passthru = 0;

	ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
	if (!ec_dev->din)
		return -ENOMEM;

	ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
	if (!ec_dev->dout)
		return -ENOMEM;

	mutex_init(&ec_dev->lock);

	cros_ec_query_all(ec_dev);

	if (ec_dev->irq) {
		err = request_threaded_irq(ec_dev->irq, NULL, ec_irq_thread,
					   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
					   "chromeos-ec", ec_dev);
		if (err) {
			dev_err(dev, "Failed to request IRQ %d: %d",
				ec_dev->irq, err);
			return err;
		}
	}

	err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO, &ec_cell, 1,
			      NULL, ec_dev->irq, NULL);
	if (err) {
		dev_err(dev,
			"Failed to register Embedded Controller subdevice %d\n",
			err);
		goto fail_mfd;
	}

	if (ec_dev->max_passthru) {
		/*
		 * Register a PD device as well on top of this device.
		 * We make the following assumptions:
		 * - behind an EC, we have a pd
		 * - only one device added.
		 * - the EC is responsive at init time (it is not true for a
		 *   sensor hub.
		 */
		err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO,
				      &ec_pd_cell, 1, NULL, ec_dev->irq, NULL);
		if (err) {
			dev_err(dev,
				"Failed to register Power Delivery subdevice %d\n",
				err);
			goto fail_mfd;
		}
	}

	if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
		err = devm_of_platform_populate(dev);
		if (err) {
			mfd_remove_devices(dev);
			dev_err(dev, "Failed to register sub-devices\n");
			goto fail_mfd;
		}
	}

	/*
	 * Clear sleep event - this will fail harmlessly on platforms that
	 * don't implement the sleep event host command.
	 */
	err = cros_ec_sleep_event(ec_dev, 0);
	if (err < 0)
		dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec",
			err);

	dev_info(dev, "Chrome EC device registered\n");

	cros_ec_acpi_install_gpe_handler(dev);

	return 0;

fail_mfd:
	if (ec_dev->irq)
		free_irq(ec_dev->irq, ec_dev);
	return err;
}
EXPORT_SYMBOL(cros_ec_register);

int cros_ec_remove(struct cros_ec_device *ec_dev)
{
	mfd_remove_devices(ec_dev->dev);

	cros_ec_acpi_remove_gpe_handler();

	if (ec_dev->irq)
		free_irq(ec_dev->irq, ec_dev);

	return 0;
}
EXPORT_SYMBOL(cros_ec_remove);

#ifdef CONFIG_PM_SLEEP
int cros_ec_suspend(struct cros_ec_device *ec_dev)
{
	struct device *dev = ec_dev->dev;
	int ret;
	u8 sleep_event;

	if (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) {
		sleep_event = HOST_SLEEP_EVENT_S3_SUSPEND;
	} else {
		sleep_event = HOST_SLEEP_EVENT_S0IX_SUSPEND;

		/* Clearing the GPE status for any pending event */
		cros_ec_acpi_clear_gpe();
	}

	ret = cros_ec_sleep_event(ec_dev, sleep_event);
	if (ret < 0)
		dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec",
			ret);

	if (device_may_wakeup(dev))
		ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);

	disable_irq(ec_dev->irq);
	ec_dev->was_wake_device = ec_dev->wake_enabled;
	ec_dev->suspended = true;

	return 0;
}
EXPORT_SYMBOL(cros_ec_suspend);

static void cros_ec_drain_events(struct cros_ec_device *ec_dev)
{
	while (cros_ec_get_next_event(ec_dev, NULL) > 0)
		blocking_notifier_call_chain(&ec_dev->event_notifier,
					     1, ec_dev);
}

int cros_ec_resume(struct cros_ec_device *ec_dev)
{
	int ret;
	u8 sleep_event;

	ec_dev->suspended = false;
	enable_irq(ec_dev->irq);

	sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ?
		      HOST_SLEEP_EVENT_S3_RESUME :
		      HOST_SLEEP_EVENT_S0IX_RESUME;

	ret = cros_ec_sleep_event(ec_dev, sleep_event);
	if (ret < 0)
		dev_dbg(ec_dev->dev, "Error %d sending resume event to ec",
			ret);

	/*
	 * In some cases, we need to distinguish between events that occur
	 * during suspend if the EC is not a wake source. For example,
	 * keypresses during suspend should be discarded if it does not wake
	 * the system.
	 *
	 * If the EC is not a wake source, drain the event queue and mark them
	 * as "queued during suspend".
	 */
	if (ec_dev->wake_enabled) {
		disable_irq_wake(ec_dev->irq);
		ec_dev->wake_enabled = 0;
	} else {
		cros_ec_drain_events(ec_dev);
	}

	return 0;
}
EXPORT_SYMBOL(cros_ec_resume);

#endif

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("ChromeOS EC core driver");
Commit	Line	Data
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
bb03ffb9	20	#include <linux/of_platform.h>
4ab6174e SG	21	#include <linux/interrupt.h>
4ab6174e SG	22	#include <linux/slab.h>
5ebeaff5	23	#include <linux/module.h>
4ab6174e SG	24	#include <linux/mfd/core.h>
4ab6174e SG	25	#include <linux/mfd/cros_ec.h>
f00c06fd	26	#include <linux/suspend.h>
6f1d912b	27	#include <asm/unaligned.h>
a6551a76	28
57b33ff0 GG	29	#define CROS_EC_DEV_EC_INDEX 0
	30	#define CROS_EC_DEV_PD_INDEX 1
	31
cf649e00	32	static struct cros_ec_platform ec_p = {
57b33ff0 GG	33	.ec_name = CROS_EC_DEV_NAME,
	34	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX),
	35	};
	36
cf649e00	37	static struct cros_ec_platform pd_p = {
57b33ff0 GG	38	.ec_name = CROS_EC_DEV_PD_NAME,
	39	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX),
	40	};
	41
cf649e00	42	static const struct mfd_cell ec_cell = {
ea01a31b	43	.name = "cros-ec-dev",
57b33ff0 GG	44	.platform_data = &ec_p,
	45	.pdata_size = sizeof(ec_p),
	46	};
	47
cf649e00	48	static const struct mfd_cell ec_pd_cell = {
ea01a31b	49	.name = "cros-ec-dev",
57b33ff0 GG	50	.platform_data = &pd_p,
57b33ff0 GG	51	.pdata_size = sizeof(pd_p),
4ab6174e SG	52	};
4ab6174e SG	53
6f1d912b VY	54	static irqreturn_t ec_irq_thread(int irq, void *data)
	55	{
	56	struct cros_ec_device *ec_dev = data;
29d99b96	57	bool wake_event = true;
6f1d912b VY	58	int ret;
6f1d912b VY	59
29d99b96 SN	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))
6f1d912b VY	68	pm_wakeup_event(ec_dev->dev, 0);
6f1d912b VY	69
6f1d912b VY	70	if (ret > 0)
	71	blocking_notifier_call_chain(&ec_dev->event_notifier,
	72	0, ec_dev);
	73	return IRQ_HANDLED;
	74	}
	75
f00c06fd SN	76	static 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
4ab6174e SG	94	int cros_ec_register(struct cros_ec_device *ec_dev)
	95	{
	96	struct device *dev = ec_dev->dev;
	97	int err = 0;
	98
6f1d912b VY	99	BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);
6f1d912b VY	100
2c7589af SB	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;
4ab6174e	112
63427530 AB	113	mutex_init(&ec_dev->lock);
63427530 AB	114
2c7589af SB	115	cros_ec_query_all(ec_dev);
2c7589af SB	116
6f1d912b VY	117	if (ec_dev->irq) {
	118	err = request_threaded_irq(ec_dev->irq, NULL, ec_irq_thread,
	119	IRQF_TRIGGER_LOW \| IRQF_ONESHOT,
	120	"chromeos-ec", ec_dev);
	121	if (err) {
	122	dev_err(dev, "Failed to request IRQ %d: %d",
	123	ec_dev->irq, err);
	124	return err;
	125	}
	126	}
	127
57b33ff0	128	err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO, &ec_cell, 1,
4ab6174e SG	129	NULL, ec_dev->irq, NULL);
4ab6174e SG	130	if (err) {
57b33ff0 GG	131	dev_err(dev,
	132	"Failed to register Embedded Controller subdevice %d\n",
	133	err);
6f1d912b	134	goto fail_mfd;
4ab6174e SG	135	}
4ab6174e SG	136
57b33ff0 GG	137	if (ec_dev->max_passthru) {
	138	/*
	139	* Register a PD device as well on top of this device.
	140	* We make the following assumptions:
	141	* - behind an EC, we have a pd
	142	* - only one device added.
	143	* - the EC is responsive at init time (it is not true for a
	144	* sensor hub.
	145	*/
	146	err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO,
	147	&ec_pd_cell, 1, NULL, ec_dev->irq, NULL);
	148	if (err) {
	149	dev_err(dev,
	150	"Failed to register Power Delivery subdevice %d\n",
	151	err);
6f1d912b	152	goto fail_mfd;
57b33ff0 GG	153	}
	154	}
	155
bb03ffb9	156	if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
2eb131ef	157	err = devm_of_platform_populate(dev);
bb03ffb9 TB	158	if (err) {
	159	mfd_remove_devices(dev);
	160	dev_err(dev, "Failed to register sub-devices\n");
6f1d912b	161	goto fail_mfd;
bb03ffb9 TB	162	}
	163	}
	164
f00c06fd SN	165	/*
	166	* Clear sleep event - this will fail harmlessly on platforms that
	167	* don't implement the sleep event host command.
	168	*/
	169	err = cros_ec_sleep_event(ec_dev, 0);
	170	if (err < 0)
	171	dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec",
	172	err);
	173
533cec8f	174	dev_info(dev, "Chrome EC device registered\n");
4ab6174e	175
e04653a9 AP	176	cros_ec_acpi_install_gpe_handler(dev);
e04653a9 AP	177
4ab6174e	178	return 0;
6f1d912b VY	179
	180	fail_mfd:
	181	if (ec_dev->irq)
	182	free_irq(ec_dev->irq, ec_dev);
	183	return err;
4ab6174e	184	}
5ebeaff5	185	EXPORT_SYMBOL(cros_ec_register);
4ab6174e SG	186
	187	int cros_ec_remove(struct cros_ec_device *ec_dev)
	188	{
	189	mfd_remove_devices(ec_dev->dev);
4ab6174e	190
e04653a9 AP	191	cros_ec_acpi_remove_gpe_handler();
e04653a9 AP	192
f58b14e6 JC	193	if (ec_dev->irq)
	194	free_irq(ec_dev->irq, ec_dev);
	195
4ab6174e SG	196	return 0;
4ab6174e SG	197	}
5ebeaff5	198	EXPORT_SYMBOL(cros_ec_remove);
4ab6174e SG	199
	200	#ifdef CONFIG_PM_SLEEP
	201	int cros_ec_suspend(struct cros_ec_device *ec_dev)
	202	{
	203	struct device *dev = ec_dev->dev;
f00c06fd SN	204	int ret;
	205	u8 sleep_event;
	206
e04653a9 AP	207	if (!IS_ENABLED(CONFIG_ACPI) \|\| pm_suspend_via_firmware()) {
	208	sleep_event = HOST_SLEEP_EVENT_S3_SUSPEND;
	209	} else {
	210	sleep_event = HOST_SLEEP_EVENT_S0IX_SUSPEND;
	211
	212	/* Clearing the GPE status for any pending event */
	213	cros_ec_acpi_clear_gpe();
	214	}
f00c06fd SN	215
	216	ret = cros_ec_sleep_event(ec_dev, sleep_event);
	217	if (ret < 0)
	218	dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec",
	219	ret);
4ab6174e SG	220
	221	if (device_may_wakeup(dev))
	222	ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
	223
	224	disable_irq(ec_dev->irq);
	225	ec_dev->was_wake_device = ec_dev->wake_enabled;
a9eb186e	226	ec_dev->suspended = true;
4ab6174e SG	227
	228	return 0;
	229	}
5ebeaff5	230	EXPORT_SYMBOL(cros_ec_suspend);
4ab6174e	231
6f1d912b VY	232	static void cros_ec_drain_events(struct cros_ec_device *ec_dev)
6f1d912b VY	233	{
29d99b96	234	while (cros_ec_get_next_event(ec_dev, NULL) > 0)
6f1d912b VY	235	blocking_notifier_call_chain(&ec_dev->event_notifier,
	236	1, ec_dev);
	237	}
	238
4ab6174e SG	239	int cros_ec_resume(struct cros_ec_device *ec_dev)
4ab6174e SG	240	{
f00c06fd SN	241	int ret;
	242	u8 sleep_event;
	243
a9eb186e	244	ec_dev->suspended = false;
4ab6174e SG	245	enable_irq(ec_dev->irq);
4ab6174e SG	246
9c576bd3 SN	247	sleep_event = (!IS_ENABLED(CONFIG_ACPI) \|\| pm_suspend_via_firmware()) ?
	248	HOST_SLEEP_EVENT_S3_RESUME :
	249	HOST_SLEEP_EVENT_S0IX_RESUME;
f00c06fd SN	250
	251	ret = cros_ec_sleep_event(ec_dev, sleep_event);
	252	if (ret < 0)
	253	dev_dbg(ec_dev->dev, "Error %d sending resume event to ec",
	254	ret);
	255
6f1d912b VY	256	/*
	257	* In some cases, we need to distinguish between events that occur
	258	* during suspend if the EC is not a wake source. For example,
	259	* keypresses during suspend should be discarded if it does not wake
	260	* the system.
	261	*
	262	* If the EC is not a wake source, drain the event queue and mark them
	263	* as "queued during suspend".
	264	*/
4ab6174e SG	265	if (ec_dev->wake_enabled) {
	266	disable_irq_wake(ec_dev->irq);
	267	ec_dev->wake_enabled = 0;
6f1d912b VY	268	} else {
6f1d912b VY	269	cros_ec_drain_events(ec_dev);
4ab6174e SG	270	}
	271
	272	return 0;
	273	}
5ebeaff5 SO	274	EXPORT_SYMBOL(cros_ec_resume);
5ebeaff5 SO	275
4ab6174e	276	#endif
a865a589 BR	277
	278	MODULE_LICENSE("GPL");
	279	MODULE_DESCRIPTION("ChromeOS EC core driver");