[mirror_ubuntu-focal-kernel.git] / drivers / platform / olpc / olpc-ec.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Generic driver for the OLPC Embedded Controller.
 *
 * Author: Andres Salomon <dilinger@queued.net>
 *
 * Copyright (C) 2011-2012 One Laptop per Child Foundation.
 */
#include <linux/completion.h>
#include <linux/debugfs.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/regulator/driver.h>
#include <linux/olpc-ec.h>

struct ec_cmd_desc {
	u8 cmd;
	u8 *inbuf, *outbuf;
	size_t inlen, outlen;

	int err;
	struct completion finished;
	struct list_head node;

	void *priv;
};

struct olpc_ec_priv {
	struct olpc_ec_driver *drv;
	u8 version;
	struct work_struct worker;
	struct mutex cmd_lock;

	/* DCON regulator */
	struct regulator_dev *dcon_rdev;
	bool dcon_enabled;

	/* Pending EC commands */
	struct list_head cmd_q;
	spinlock_t cmd_q_lock;

	struct dentry *dbgfs_dir;

	/*
	 * EC event mask to be applied during suspend (defining wakeup
	 * sources).
	 */
	u16 ec_wakeup_mask;

	/*
	 * Running an EC command while suspending means we don't always finish
	 * the command before the machine suspends.  This means that the EC
	 * is expecting the command protocol to finish, but we after a period
	 * of time (while the OS is asleep) the EC times out and restarts its
	 * idle loop.  Meanwhile, the OS wakes up, thinks it's still in the
	 * middle of the command protocol, starts throwing random things at
	 * the EC... and everyone's uphappy.
	 */
	bool suspended;
};

static struct olpc_ec_driver *ec_driver;
static struct olpc_ec_priv *ec_priv;
static void *ec_cb_arg;

void olpc_ec_driver_register(struct olpc_ec_driver *drv, void *arg)
{
	ec_driver = drv;
	ec_cb_arg = arg;
}
EXPORT_SYMBOL_GPL(olpc_ec_driver_register);

static void olpc_ec_worker(struct work_struct *w)
{
	struct olpc_ec_priv *ec = container_of(w, struct olpc_ec_priv, worker);
	struct ec_cmd_desc *desc = NULL;
	unsigned long flags;

	/* Grab the first pending command from the queue */
	spin_lock_irqsave(&ec->cmd_q_lock, flags);
	if (!list_empty(&ec->cmd_q)) {
		desc = list_first_entry(&ec->cmd_q, struct ec_cmd_desc, node);
		list_del(&desc->node);
	}
	spin_unlock_irqrestore(&ec->cmd_q_lock, flags);

	/* Do we actually have anything to do? */
	if (!desc)
		return;

	/* Protect the EC hw with a mutex; only run one cmd at a time */
	mutex_lock(&ec->cmd_lock);
	desc->err = ec_driver->ec_cmd(desc->cmd, desc->inbuf, desc->inlen,
			desc->outbuf, desc->outlen, ec_cb_arg);
	mutex_unlock(&ec->cmd_lock);

	/* Finished, wake up olpc_ec_cmd() */
	complete(&desc->finished);

	/* Run the worker thread again in case there are more cmds pending */
	schedule_work(&ec->worker);
}

/*
 * Throw a cmd descripter onto the list.  We now have SMP OLPC machines, so
 * locking is pretty critical.
 */
static void queue_ec_descriptor(struct ec_cmd_desc *desc,
		struct olpc_ec_priv *ec)
{
	unsigned long flags;

	INIT_LIST_HEAD(&desc->node);

	spin_lock_irqsave(&ec->cmd_q_lock, flags);
	list_add_tail(&desc->node, &ec->cmd_q);
	spin_unlock_irqrestore(&ec->cmd_q_lock, flags);

	schedule_work(&ec->worker);
}

int olpc_ec_cmd(u8 cmd, u8 *inbuf, size_t inlen, u8 *outbuf, size_t outlen)
{
	struct olpc_ec_priv *ec = ec_priv;
	struct ec_cmd_desc desc;

	/* Driver not yet registered. */
	if (!ec_driver)
		return -EPROBE_DEFER;

	if (WARN_ON(!ec_driver->ec_cmd))
		return -ENODEV;

	if (!ec)
		return -ENOMEM;

	/* Suspending in the middle of a command hoses things really badly */
	if (WARN_ON(ec->suspended))
		return -EBUSY;

	might_sleep();

	desc.cmd = cmd;
	desc.inbuf = inbuf;
	desc.outbuf = outbuf;
	desc.inlen = inlen;
	desc.outlen = outlen;
	desc.err = 0;
	init_completion(&desc.finished);

	queue_ec_descriptor(&desc, ec);

	/* Timeouts must be handled in the platform-specific EC hook */
	wait_for_completion(&desc.finished);

	/* The worker thread dequeues the cmd; no need to do anything here */
	return desc.err;
}
EXPORT_SYMBOL_GPL(olpc_ec_cmd);

void olpc_ec_wakeup_set(u16 value)
{
	struct olpc_ec_priv *ec = ec_priv;

	if (WARN_ON(!ec))
		return;

	ec->ec_wakeup_mask |= value;
}
EXPORT_SYMBOL_GPL(olpc_ec_wakeup_set);

void olpc_ec_wakeup_clear(u16 value)
{
	struct olpc_ec_priv *ec = ec_priv;

	if (WARN_ON(!ec))
		return;

	ec->ec_wakeup_mask &= ~value;
}
EXPORT_SYMBOL_GPL(olpc_ec_wakeup_clear);

int olpc_ec_mask_write(u16 bits)
{
	struct olpc_ec_priv *ec = ec_priv;

	if (WARN_ON(!ec))
		return -ENODEV;

	/* EC version 0x5f adds support for wide SCI mask */
	if (ec->version >= 0x5f) {
		__be16 ec_word = cpu_to_be16(bits);

		return olpc_ec_cmd(EC_WRITE_EXT_SCI_MASK, (void *)&ec_word, 2, NULL, 0);
	} else {
		u8 ec_byte = bits & 0xff;

		return olpc_ec_cmd(EC_WRITE_SCI_MASK, &ec_byte, 1, NULL, 0);
	}
}
EXPORT_SYMBOL_GPL(olpc_ec_mask_write);

/*
 * Returns true if the compile and runtime configurations allow for EC events
 * to wake the system.
 */
bool olpc_ec_wakeup_available(void)
{
	if (WARN_ON(!ec_driver))
		return false;

	return ec_driver->wakeup_available;
}
EXPORT_SYMBOL_GPL(olpc_ec_wakeup_available);

int olpc_ec_sci_query(u16 *sci_value)
{
	struct olpc_ec_priv *ec = ec_priv;
	int ret;

	if (WARN_ON(!ec))
		return -ENODEV;

	/* EC version 0x5f adds support for wide SCI mask */
	if (ec->version >= 0x5f) {
		__be16 ec_word;

		ret = olpc_ec_cmd(EC_EXT_SCI_QUERY, NULL, 0, (void *)&ec_word, 2);
		if (ret == 0)
			*sci_value = be16_to_cpu(ec_word);
	} else {
		u8 ec_byte;

		ret = olpc_ec_cmd(EC_SCI_QUERY, NULL, 0, &ec_byte, 1);
		if (ret == 0)
			*sci_value = ec_byte;
	}

	return ret;
}
EXPORT_SYMBOL_GPL(olpc_ec_sci_query);

#ifdef CONFIG_DEBUG_FS

/*
 * debugfs support for "generic commands", to allow sending
 * arbitrary EC commands from userspace.
 */

#define EC_MAX_CMD_ARGS (5 + 1)		/* cmd byte + 5 args */
#define EC_MAX_CMD_REPLY (8)

static DEFINE_MUTEX(ec_dbgfs_lock);
static unsigned char ec_dbgfs_resp[EC_MAX_CMD_REPLY];
static unsigned int ec_dbgfs_resp_bytes;

static ssize_t ec_dbgfs_cmd_write(struct file *file, const char __user *buf,
		size_t size, loff_t *ppos)
{
	int i, m;
	unsigned char ec_cmd[EC_MAX_CMD_ARGS];
	unsigned int ec_cmd_int[EC_MAX_CMD_ARGS];
	char cmdbuf[64];
	int ec_cmd_bytes;

	mutex_lock(&ec_dbgfs_lock);

	size = simple_write_to_buffer(cmdbuf, sizeof(cmdbuf), ppos, buf, size);

	m = sscanf(cmdbuf, "%x:%u %x %x %x %x %x", &ec_cmd_int[0],
			&ec_dbgfs_resp_bytes, &ec_cmd_int[1], &ec_cmd_int[2],
			&ec_cmd_int[3], &ec_cmd_int[4], &ec_cmd_int[5]);
	if (m < 2 || ec_dbgfs_resp_bytes > EC_MAX_CMD_REPLY) {
		/* reset to prevent overflow on read */
		ec_dbgfs_resp_bytes = 0;

		pr_debug("olpc-ec: bad ec cmd:  cmd:response-count [arg1 [arg2 ...]]\n");
		size = -EINVAL;
		goto out;
	}

	/* convert scanf'd ints to char */
	ec_cmd_bytes = m - 2;
	for (i = 0; i <= ec_cmd_bytes; i++)
		ec_cmd[i] = ec_cmd_int[i];

	pr_debug("olpc-ec: debugfs cmd 0x%02x with %d args %5ph, want %d returns\n",
			ec_cmd[0], ec_cmd_bytes, ec_cmd + 1,
			ec_dbgfs_resp_bytes);

	olpc_ec_cmd(ec_cmd[0], (ec_cmd_bytes == 0) ? NULL : &ec_cmd[1],
			ec_cmd_bytes, ec_dbgfs_resp, ec_dbgfs_resp_bytes);

	pr_debug("olpc-ec: response %8ph (%d bytes expected)\n",
			ec_dbgfs_resp, ec_dbgfs_resp_bytes);

out:
	mutex_unlock(&ec_dbgfs_lock);
	return size;
}

static ssize_t ec_dbgfs_cmd_read(struct file *file, char __user *buf,
		size_t size, loff_t *ppos)
{
	unsigned int i, r;
	char *rp;
	char respbuf[64];

	mutex_lock(&ec_dbgfs_lock);
	rp = respbuf;
	rp += sprintf(rp, "%02x", ec_dbgfs_resp[0]);
	for (i = 1; i < ec_dbgfs_resp_bytes; i++)
		rp += sprintf(rp, ", %02x", ec_dbgfs_resp[i]);
	mutex_unlock(&ec_dbgfs_lock);
	rp += sprintf(rp, "\n");

	r = rp - respbuf;
	return simple_read_from_buffer(buf, size, ppos, respbuf, r);
}

static const struct file_operations ec_dbgfs_ops = {
	.write = ec_dbgfs_cmd_write,
	.read = ec_dbgfs_cmd_read,
};

static struct dentry *olpc_ec_setup_debugfs(void)
{
	struct dentry *dbgfs_dir;

	dbgfs_dir = debugfs_create_dir("olpc-ec", NULL);
	if (IS_ERR_OR_NULL(dbgfs_dir))
		return NULL;

	debugfs_create_file("cmd", 0600, dbgfs_dir, NULL, &ec_dbgfs_ops);

	return dbgfs_dir;
}

#else

static struct dentry *olpc_ec_setup_debugfs(void)
{
	return NULL;
}

#endif /* CONFIG_DEBUG_FS */

static int olpc_ec_set_dcon_power(struct olpc_ec_priv *ec, bool state)
{
	unsigned char ec_byte = state;
	int ret;

	if (ec->dcon_enabled == state)
		return 0;

	ret = olpc_ec_cmd(EC_DCON_POWER_MODE, &ec_byte, 1, NULL, 0);
	if (ret)
		return ret;

	ec->dcon_enabled = state;
	return 0;
}

static int dcon_regulator_enable(struct regulator_dev *rdev)
{
	struct olpc_ec_priv *ec = rdev_get_drvdata(rdev);

	return olpc_ec_set_dcon_power(ec, true);
}

static int dcon_regulator_disable(struct regulator_dev *rdev)
{
	struct olpc_ec_priv *ec = rdev_get_drvdata(rdev);

	return olpc_ec_set_dcon_power(ec, false);
}

static int dcon_regulator_is_enabled(struct regulator_dev *rdev)
{
	struct olpc_ec_priv *ec = rdev_get_drvdata(rdev);

	return ec->dcon_enabled ? 1 : 0;
}

static struct regulator_ops dcon_regulator_ops = {
	.enable		= dcon_regulator_enable,
	.disable	= dcon_regulator_disable,
	.is_enabled	= dcon_regulator_is_enabled,
};

static const struct regulator_desc dcon_desc = {
	.name	= "dcon",
	.id	= 0,
	.ops	= &dcon_regulator_ops,
	.type	= REGULATOR_VOLTAGE,
	.owner	= THIS_MODULE,
};

static int olpc_ec_probe(struct platform_device *pdev)
{
	struct olpc_ec_priv *ec;
	struct regulator_config config = { };
	int err;

	if (!ec_driver)
		return -ENODEV;

	ec = kzalloc(sizeof(*ec), GFP_KERNEL);
	if (!ec)
		return -ENOMEM;

	ec->drv = ec_driver;
	INIT_WORK(&ec->worker, olpc_ec_worker);
	mutex_init(&ec->cmd_lock);

	INIT_LIST_HEAD(&ec->cmd_q);
	spin_lock_init(&ec->cmd_q_lock);

	ec_priv = ec;
	platform_set_drvdata(pdev, ec);

	/* get the EC revision */
	err = olpc_ec_cmd(EC_FIRMWARE_REV, NULL, 0, &ec->version, 1);
	if (err)
		goto error;

	config.dev = pdev->dev.parent;
	config.driver_data = ec;
	ec->dcon_enabled = true;
	ec->dcon_rdev = devm_regulator_register(&pdev->dev, &dcon_desc,
								&config);
	if (IS_ERR(ec->dcon_rdev)) {
		dev_err(&pdev->dev, "failed to register DCON regulator\n");
		err = PTR_ERR(ec->dcon_rdev);
		goto error;
	}

	ec->dbgfs_dir = olpc_ec_setup_debugfs();

	return 0;

error:
	ec_priv = NULL;
	kfree(ec);
	return err;
}

static int olpc_ec_suspend(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct olpc_ec_priv *ec = platform_get_drvdata(pdev);
	int err = 0;

	olpc_ec_mask_write(ec->ec_wakeup_mask);

	if (ec_driver->suspend)
		err = ec_driver->suspend(pdev);
	if (!err)
		ec->suspended = true;

	return err;
}

static int olpc_ec_resume(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct olpc_ec_priv *ec = platform_get_drvdata(pdev);

	ec->suspended = false;
	return ec_driver->resume ? ec_driver->resume(pdev) : 0;
}

static const struct dev_pm_ops olpc_ec_pm_ops = {
	.suspend_late = olpc_ec_suspend,
	.resume_early = olpc_ec_resume,
};

static struct platform_driver olpc_ec_plat_driver = {
	.probe = olpc_ec_probe,
	.driver = {
		.name = "olpc-ec",
		.pm = &olpc_ec_pm_ops,
	},
};

static int __init olpc_ec_init_module(void)
{
	return platform_driver_register(&olpc_ec_plat_driver);
}
arch_initcall(olpc_ec_init_module);
Commit	Line	Data
ff206db4	1	// SPDX-License-Identifier: GPL-2.0-or-later
392a325c AS	2	/*
	3	* Generic driver for the OLPC Embedded Controller.
	4	*
f48d1496 PG	5	* Author: Andres Salomon <dilinger@queued.net>
f48d1496 PG	6	*
392a325c	7	* Copyright (C) 2011-2012 One Laptop per Child Foundation.
392a325c	8	*/
3d26c20b	9	#include <linux/completion.h>
6cca83d4	10	#include <linux/debugfs.h>
3d26c20b AS	11	#include <linux/spinlock.h>
3d26c20b AS	12	#include <linux/mutex.h>
ac250415	13	#include <linux/platform_device.h>
d278b7a2	14	#include <linux/slab.h>
3d26c20b	15	#include <linux/workqueue.h>
f48d1496	16	#include <linux/init.h>
3d26c20b	17	#include <linux/list.h>
231c0c21	18	#include <linux/regulator/driver.h>
3d26c20b	19	#include <linux/olpc-ec.h>
392a325c	20
3d26c20b AS	21	struct ec_cmd_desc {
	22	u8 cmd;
	23	u8 inbuf, outbuf;
	24	size_t inlen, outlen;
	25
	26	int err;
	27	struct completion finished;
	28	struct list_head node;
	29
	30	void *priv;
	31	};
	32
d278b7a2 AS	33	struct olpc_ec_priv {
d278b7a2 AS	34	struct olpc_ec_driver *drv;
ec9964b4	35	u8 version;
99ecb01c AS	36	struct work_struct worker;
	37	struct mutex cmd_lock;
	38
231c0c21 LR	39	/* DCON regulator */
	40	struct regulator_dev *dcon_rdev;
	41	bool dcon_enabled;
	42
99ecb01c AS	43	/* Pending EC commands */
	44	struct list_head cmd_q;
	45	spinlock_t cmd_q_lock;
d278b7a2	46
6cca83d4 AS	47	struct dentry *dbgfs_dir;
6cca83d4 AS	48
ec9964b4 LR	49	/*
	50	* EC event mask to be applied during suspend (defining wakeup
	51	* sources).
	52	*/
	53	u16 ec_wakeup_mask;
	54
d278b7a2 AS	55	/*
	56	* Running an EC command while suspending means we don't always finish
	57	* the command before the machine suspends. This means that the EC
	58	* is expecting the command protocol to finish, but we after a period
	59	* of time (while the OS is asleep) the EC times out and restarts its
	60	* idle loop. Meanwhile, the OS wakes up, thinks it's still in the
	61	* middle of the command protocol, starts throwing random things at
	62	* the EC... and everyone's uphappy.
	63	*/
	64	bool suspended;
	65	};
	66
3d26c20b	67	static struct olpc_ec_driver *ec_driver;
d278b7a2	68	static struct olpc_ec_priv *ec_priv;
3d26c20b	69	static void *ec_cb_arg;
3d26c20b AS	70
	71	void olpc_ec_driver_register(struct olpc_ec_driver drv, void arg)
	72	{
	73	ec_driver = drv;
	74	ec_cb_arg = arg;
	75	}
	76	EXPORT_SYMBOL_GPL(olpc_ec_driver_register);
	77
	78	static void olpc_ec_worker(struct work_struct *w)
	79	{
99ecb01c	80	struct olpc_ec_priv *ec = container_of(w, struct olpc_ec_priv, worker);
3d26c20b AS	81	struct ec_cmd_desc *desc = NULL;
	82	unsigned long flags;
	83
	84	/* Grab the first pending command from the queue */
99ecb01c AS	85	spin_lock_irqsave(&ec->cmd_q_lock, flags);
	86	if (!list_empty(&ec->cmd_q)) {
	87	desc = list_first_entry(&ec->cmd_q, struct ec_cmd_desc, node);
3d26c20b AS	88	list_del(&desc->node);
3d26c20b AS	89	}
99ecb01c	90	spin_unlock_irqrestore(&ec->cmd_q_lock, flags);
3d26c20b AS	91
	92	/* Do we actually have anything to do? */
	93	if (!desc)
	94	return;
	95
	96	/* Protect the EC hw with a mutex; only run one cmd at a time */
99ecb01c	97	mutex_lock(&ec->cmd_lock);
3d26c20b AS	98	desc->err = ec_driver->ec_cmd(desc->cmd, desc->inbuf, desc->inlen,
3d26c20b AS	99	desc->outbuf, desc->outlen, ec_cb_arg);
99ecb01c	100	mutex_unlock(&ec->cmd_lock);
3d26c20b AS	101
	102	/* Finished, wake up olpc_ec_cmd() */
	103	complete(&desc->finished);
	104
	105	/* Run the worker thread again in case there are more cmds pending */
99ecb01c	106	schedule_work(&ec->worker);
3d26c20b AS	107	}
	108
	109	/*
	110	* Throw a cmd descripter onto the list. We now have SMP OLPC machines, so
	111	* locking is pretty critical.
	112	*/
99ecb01c AS	113	static void queue_ec_descriptor(struct ec_cmd_desc *desc,
99ecb01c AS	114	struct olpc_ec_priv *ec)
3d26c20b AS	115	{
	116	unsigned long flags;
	117
	118	INIT_LIST_HEAD(&desc->node);
	119
99ecb01c AS	120	spin_lock_irqsave(&ec->cmd_q_lock, flags);
	121	list_add_tail(&desc->node, &ec->cmd_q);
	122	spin_unlock_irqrestore(&ec->cmd_q_lock, flags);
3d26c20b	123
99ecb01c	124	schedule_work(&ec->worker);
3d26c20b AS	125	}
3d26c20b AS	126
392a325c AS	127	int olpc_ec_cmd(u8 cmd, u8 inbuf, size_t inlen, u8 outbuf, size_t outlen)
392a325c AS	128	{
d278b7a2	129	struct olpc_ec_priv *ec = ec_priv;
3d26c20b AS	130	struct ec_cmd_desc desc;
3d26c20b AS	131
560331ea LR	132	/* Driver not yet registered. */
	133	if (!ec_driver)
	134	return -EPROBE_DEFER;
	135
	136	if (WARN_ON(!ec_driver->ec_cmd))
3d26c20b AS	137	return -ENODEV;
3d26c20b AS	138
d278b7a2 AS	139	if (!ec)
	140	return -ENOMEM;
	141
	142	/* Suspending in the middle of a command hoses things really badly */
	143	if (WARN_ON(ec->suspended))
	144	return -EBUSY;
	145
3d26c20b AS	146	might_sleep();
	147
	148	desc.cmd = cmd;
	149	desc.inbuf = inbuf;
	150	desc.outbuf = outbuf;
	151	desc.inlen = inlen;
	152	desc.outlen = outlen;
	153	desc.err = 0;
	154	init_completion(&desc.finished);
	155
99ecb01c	156	queue_ec_descriptor(&desc, ec);
3d26c20b AS	157
	158	/* Timeouts must be handled in the platform-specific EC hook */
	159	wait_for_completion(&desc.finished);
	160
	161	/* The worker thread dequeues the cmd; no need to do anything here */
	162	return desc.err;
392a325c AS	163	}
392a325c AS	164	EXPORT_SYMBOL_GPL(olpc_ec_cmd);
ac250415	165
ec9964b4 LR	166	void olpc_ec_wakeup_set(u16 value)
	167	{
	168	struct olpc_ec_priv *ec = ec_priv;
	169
	170	if (WARN_ON(!ec))
	171	return;
	172
	173	ec->ec_wakeup_mask \|= value;
	174	}
	175	EXPORT_SYMBOL_GPL(olpc_ec_wakeup_set);
	176
	177	void olpc_ec_wakeup_clear(u16 value)
	178	{
	179	struct olpc_ec_priv *ec = ec_priv;
	180
	181	if (WARN_ON(!ec))
	182	return;
	183
	184	ec->ec_wakeup_mask &= ~value;
	185	}
	186	EXPORT_SYMBOL_GPL(olpc_ec_wakeup_clear);
	187
	188	int olpc_ec_mask_write(u16 bits)
	189	{
	190	struct olpc_ec_priv *ec = ec_priv;
	191
	192	if (WARN_ON(!ec))
	193	return -ENODEV;
	194
	195	/* EC version 0x5f adds support for wide SCI mask */
	196	if (ec->version >= 0x5f) {
	197	__be16 ec_word = cpu_to_be16(bits);
	198
	199	return olpc_ec_cmd(EC_WRITE_EXT_SCI_MASK, (void *)&ec_word, 2, NULL, 0);
	200	} else {
	201	u8 ec_byte = bits & 0xff;
	202
	203	return olpc_ec_cmd(EC_WRITE_SCI_MASK, &ec_byte, 1, NULL, 0);
	204	}
	205	}
	206	EXPORT_SYMBOL_GPL(olpc_ec_mask_write);
	207
	208	/*
	209	* Returns true if the compile and runtime configurations allow for EC events
	210	* to wake the system.
	211	*/
	212	bool olpc_ec_wakeup_available(void)
	213	{
	214	if (WARN_ON(!ec_driver))
	215	return false;
	216
	217	return ec_driver->wakeup_available;
	218	}
	219	EXPORT_SYMBOL_GPL(olpc_ec_wakeup_available);
	220
	221	int olpc_ec_sci_query(u16 *sci_value)
	222	{
	223	struct olpc_ec_priv *ec = ec_priv;
	224	int ret;
	225
	226	if (WARN_ON(!ec))
	227	return -ENODEV;
	228
	229	/* EC version 0x5f adds support for wide SCI mask */
230	if (ec->version >= 0x5f) {
231	__be16 ec_word;
232
233	ret = olpc_ec_cmd(EC_EXT_SCI_QUERY, NULL, 0, (void *)&ec_word, 2);
234	if (ret == 0)
235	*sci_value = be16_to_cpu(ec_word);
236	} else {
237	u8 ec_byte;
238
239	ret = olpc_ec_cmd(EC_SCI_QUERY, NULL, 0, &ec_byte, 1);
240	if (ret == 0)
241	*sci_value = ec_byte;
242	}
243
244	return ret;
245	}
246	EXPORT_SYMBOL_GPL(olpc_ec_sci_query);
247
6cca83d4 AS	248	#ifdef CONFIG_DEBUG_FS
	249
	250	/*
	251	* debugfs support for "generic commands", to allow sending
	252	* arbitrary EC commands from userspace.
	253	*/
	254
	255	#define EC_MAX_CMD_ARGS (5 + 1) /* cmd byte + 5 args */
	256	#define EC_MAX_CMD_REPLY (8)
	257
	258	static DEFINE_MUTEX(ec_dbgfs_lock);
	259	static unsigned char ec_dbgfs_resp[EC_MAX_CMD_REPLY];
	260	static unsigned int ec_dbgfs_resp_bytes;
	261
	262	static ssize_t ec_dbgfs_cmd_write(struct file file, const char __user buf,
	263	size_t size, loff_t *ppos)
	264	{
	265	int i, m;
	266	unsigned char ec_cmd[EC_MAX_CMD_ARGS];
	267	unsigned int ec_cmd_int[EC_MAX_CMD_ARGS];
	268	char cmdbuf[64];
	269	int ec_cmd_bytes;
	270
	271	mutex_lock(&ec_dbgfs_lock);
	272
	273	size = simple_write_to_buffer(cmdbuf, sizeof(cmdbuf), ppos, buf, size);
	274
	275	m = sscanf(cmdbuf, "%x:%u %x %x %x %x %x", &ec_cmd_int[0],
	276	&ec_dbgfs_resp_bytes, &ec_cmd_int[1], &ec_cmd_int[2],
	277	&ec_cmd_int[3], &ec_cmd_int[4], &ec_cmd_int[5]);
	278	if (m < 2 \|\| ec_dbgfs_resp_bytes > EC_MAX_CMD_REPLY) {
	279	/* reset to prevent overflow on read */
	280	ec_dbgfs_resp_bytes = 0;
	281
	282	pr_debug("olpc-ec: bad ec cmd: cmd:response-count [arg1 [arg2 ...]]\n");
	283	size = -EINVAL;
	284	goto out;
	285	}
	286
	287	/* convert scanf'd ints to char */
	288	ec_cmd_bytes = m - 2;
	289	for (i = 0; i <= ec_cmd_bytes; i++)
	290	ec_cmd[i] = ec_cmd_int[i];
	291
7d3777d1 AS	292	pr_debug("olpc-ec: debugfs cmd 0x%02x with %d args %5ph, want %d returns\n",
	293	ec_cmd[0], ec_cmd_bytes, ec_cmd + 1,
	294	ec_dbgfs_resp_bytes);
6cca83d4 AS	295
	296	olpc_ec_cmd(ec_cmd[0], (ec_cmd_bytes == 0) ? NULL : &ec_cmd[1],
	297	ec_cmd_bytes, ec_dbgfs_resp, ec_dbgfs_resp_bytes);
	298
7d3777d1 AS	299	pr_debug("olpc-ec: response %8ph (%d bytes expected)\n",
7d3777d1 AS	300	ec_dbgfs_resp, ec_dbgfs_resp_bytes);
6cca83d4 AS	301
	302	out:
	303	mutex_unlock(&ec_dbgfs_lock);
	304	return size;
	305	}
	306
	307	static ssize_t ec_dbgfs_cmd_read(struct file file, char __user buf,
	308	size_t size, loff_t *ppos)
	309	{
	310	unsigned int i, r;
	311	char *rp;
	312	char respbuf[64];
	313
	314	mutex_lock(&ec_dbgfs_lock);
	315	rp = respbuf;
	316	rp += sprintf(rp, "%02x", ec_dbgfs_resp[0]);
	317	for (i = 1; i < ec_dbgfs_resp_bytes; i++)
	318	rp += sprintf(rp, ", %02x", ec_dbgfs_resp[i]);
	319	mutex_unlock(&ec_dbgfs_lock);
	320	rp += sprintf(rp, "\n");
	321
	322	r = rp - respbuf;
	323	return simple_read_from_buffer(buf, size, ppos, respbuf, r);
	324	}
	325
	326	static const struct file_operations ec_dbgfs_ops = {
	327	.write = ec_dbgfs_cmd_write,
	328	.read = ec_dbgfs_cmd_read,
	329	};
	330
	331	static struct dentry *olpc_ec_setup_debugfs(void)
	332	{
	333	struct dentry *dbgfs_dir;
	334
	335	dbgfs_dir = debugfs_create_dir("olpc-ec", NULL);
	336	if (IS_ERR_OR_NULL(dbgfs_dir))
	337	return NULL;
	338
	339	debugfs_create_file("cmd", 0600, dbgfs_dir, NULL, &ec_dbgfs_ops);
	340
	341	return dbgfs_dir;
	342	}
	343
	344	#else
	345
	346	static struct dentry *olpc_ec_setup_debugfs(void)
	347	{
	348	return NULL;
	349	}
	350
	351	#endif /* CONFIG_DEBUG_FS */
	352
231c0c21 LR	353	static int olpc_ec_set_dcon_power(struct olpc_ec_priv *ec, bool state)
	354	{
	355	unsigned char ec_byte = state;
	356	int ret;
	357
	358	if (ec->dcon_enabled == state)
	359	return 0;
	360
	361	ret = olpc_ec_cmd(EC_DCON_POWER_MODE, &ec_byte, 1, NULL, 0);
	362	if (ret)
	363	return ret;
	364
	365	ec->dcon_enabled = state;
	366	return 0;
	367	}
	368
	369	static int dcon_regulator_enable(struct regulator_dev *rdev)
	370	{
	371	struct olpc_ec_priv *ec = rdev_get_drvdata(rdev);
	372
	373	return olpc_ec_set_dcon_power(ec, true);
	374	}
	375
	376	static int dcon_regulator_disable(struct regulator_dev *rdev)
	377	{
	378	struct olpc_ec_priv *ec = rdev_get_drvdata(rdev);
	379
	380	return olpc_ec_set_dcon_power(ec, false);
	381	}
	382
	383	static int dcon_regulator_is_enabled(struct regulator_dev *rdev)
	384	{
	385	struct olpc_ec_priv *ec = rdev_get_drvdata(rdev);
	386
	387	return ec->dcon_enabled ? 1 : 0;
	388	}
	389
	390	static struct regulator_ops dcon_regulator_ops = {
	391	.enable = dcon_regulator_enable,
	392	.disable = dcon_regulator_disable,
	393	.is_enabled = dcon_regulator_is_enabled,
	394	};
	395
	396	static const struct regulator_desc dcon_desc = {
	397	.name = "dcon",
	398	.id = 0,
	399	.ops = &dcon_regulator_ops,
	400	.type = REGULATOR_VOLTAGE,
	401	.owner = THIS_MODULE,
	402	};
	403
ac250415 AS	404	static int olpc_ec_probe(struct platform_device *pdev)
ac250415 AS	405	{
d278b7a2	406	struct olpc_ec_priv *ec;
231c0c21	407	struct regulator_config config = { };
ac250415 AS	408	int err;
	409
	410	if (!ec_driver)
	411	return -ENODEV;
	412
d278b7a2 AS	413	ec = kzalloc(sizeof(*ec), GFP_KERNEL);
	414	if (!ec)
	415	return -ENOMEM;
99ecb01c	416
d278b7a2	417	ec->drv = ec_driver;
99ecb01c AS	418	INIT_WORK(&ec->worker, olpc_ec_worker);
	419	mutex_init(&ec->cmd_lock);
	420
	421	INIT_LIST_HEAD(&ec->cmd_q);
	422	spin_lock_init(&ec->cmd_q_lock);
	423
d278b7a2 AS	424	ec_priv = ec;
	425	platform_set_drvdata(pdev, ec);
	426
ec9964b4 LR	427	/* get the EC revision */
ec9964b4 LR	428	err = olpc_ec_cmd(EC_FIRMWARE_REV, NULL, 0, &ec->version, 1);
cf5e6a71 LR	429	if (err)
cf5e6a71 LR	430	goto error;
ac250415	431
231c0c21 LR	432	config.dev = pdev->dev.parent;
	433	config.driver_data = ec;
	434	ec->dcon_enabled = true;
	435	ec->dcon_rdev = devm_regulator_register(&pdev->dev, &dcon_desc,
	436	&config);
	437	if (IS_ERR(ec->dcon_rdev)) {
	438	dev_err(&pdev->dev, "failed to register DCON regulator\n");
3c555a78	439	err = PTR_ERR(ec->dcon_rdev);
cf5e6a71	440	goto error;
231c0c21 LR	441	}
231c0c21 LR	442
ec9964b4 LR	443	ec->dbgfs_dir = olpc_ec_setup_debugfs();
ec9964b4 LR	444
cf5e6a71 LR	445	return 0;
	446
	447	error:
	448	ec_priv = NULL;
	449	kfree(ec);
ac250415 AS	450	return err;
	451	}
	452
	453	static int olpc_ec_suspend(struct device *dev)
	454	{
	455	struct platform_device *pdev = to_platform_device(dev);
d278b7a2 AS	456	struct olpc_ec_priv *ec = platform_get_drvdata(pdev);
	457	int err = 0;
	458
ec9964b4 LR	459	olpc_ec_mask_write(ec->ec_wakeup_mask);
ec9964b4 LR	460
d278b7a2 AS	461	if (ec_driver->suspend)
	462	err = ec_driver->suspend(pdev);
	463	if (!err)
	464	ec->suspended = true;
	465
	466	return err;
ac250415 AS	467	}
	468
	469	static int olpc_ec_resume(struct device *dev)
	470	{
	471	struct platform_device *pdev = to_platform_device(dev);
d278b7a2 AS	472	struct olpc_ec_priv *ec = platform_get_drvdata(pdev);
	473
	474	ec->suspended = false;
ac250415 AS	475	return ec_driver->resume ? ec_driver->resume(pdev) : 0;
	476	}
	477
	478	static const struct dev_pm_ops olpc_ec_pm_ops = {
	479	.suspend_late = olpc_ec_suspend,
	480	.resume_early = olpc_ec_resume,
	481	};
	482
	483	static struct platform_driver olpc_ec_plat_driver = {
	484	.probe = olpc_ec_probe,
	485	.driver = {
	486	.name = "olpc-ec",
	487	.pm = &olpc_ec_pm_ops,
	488	},
	489	};
	490
	491	static int __init olpc_ec_init_module(void)
	492	{
	493	return platform_driver_register(&olpc_ec_plat_driver);
	494	}
93dbc1b3	495	arch_initcall(olpc_ec_init_module);