smu.c

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	 * for power management.
	 * For now, we don't power manage machines with an SMU chip,
	 * I'm a bit too far from figuring out how that works with those
	 * new chipsets, but that will come back and bite us
	 */
	of_register_platform_driver(&smu_of_platform_driver);
	return 0;
}

device_initcall(smu_init_sysfs);

struct of_device *smu_get_ofdev(void)
{
	if (!smu)
		return NULL;
	return smu->of_dev;
}

EXPORT_SYMBOL_GPL(smu_get_ofdev);

/*
 * i2c interface
 */

static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
{
	void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
	void *misc = cmd->misc;
	unsigned long flags;

	/* Check for read case */
	if (!fail && cmd->read) {
		if (cmd->pdata[0] < 1)
			fail = 1;
		else
			memcpy(cmd->info.data, &cmd->pdata[1],
			       cmd->info.datalen);
	}

	DPRINTK("SMU: completing, success: %d\n", !fail);

	/* Update status and mark no pending i2c command with lock
	 * held so nobody comes in while we dequeue an eventual
	 * pending next i2c command
	 */
	spin_lock_irqsave(&smu->lock, flags);
	smu->cmd_i2c_cur = NULL;
	wmb();
	cmd->status = fail ? -EIO : 0;

	/* Is there another i2c command waiting ? */
	if (!list_empty(&smu->cmd_i2c_list)) {
		struct smu_i2c_cmd *newcmd;

		/* Fetch it, new current, remove from list */
		newcmd = list_entry(smu->cmd_i2c_list.next,
				    struct smu_i2c_cmd, link);
		smu->cmd_i2c_cur = newcmd;
		list_del(&cmd->link);

		/* Queue with low level smu */
		list_add_tail(&cmd->scmd.link, &smu->cmd_list);
		if (smu->cmd_cur == NULL)
			smu_start_cmd();
	}
	spin_unlock_irqrestore(&smu->lock, flags);

	/* Call command completion handler if any */
	if (done)
		done(cmd, misc);

}


static void smu_i2c_retry(unsigned long data)
{
	struct smu_i2c_cmd	*cmd = smu->cmd_i2c_cur;

	DPRINTK("SMU: i2c failure, requeuing...\n");

	/* requeue command simply by resetting reply_len */
	cmd->pdata[0] = 0xff;
	cmd->scmd.reply_len = sizeof(cmd->pdata);
	smu_queue_cmd(&cmd->scmd);
}


static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
{
	struct smu_i2c_cmd	*cmd = misc;
	int			fail = 0;

	DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
		cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);

	/* Check for possible status */
	if (scmd->status < 0)
		fail = 1;
	else if (cmd->read) {
		if (cmd->stage == 0)
			fail = cmd->pdata[0] != 0;
		else
			fail = cmd->pdata[0] >= 0x80;
	} else {
		fail = cmd->pdata[0] != 0;
	}

	/* Handle failures by requeuing command, after 5ms interval
	 */
	if (fail && --cmd->retries > 0) {
		DPRINTK("SMU: i2c failure, starting timer...\n");
		BUG_ON(cmd != smu->cmd_i2c_cur);
		if (!smu_irq_inited) {
			mdelay(5);
			smu_i2c_retry(0);
			return;
		}
		mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
		return;
	}

	/* If failure or stage 1, command is complete */
	if (fail || cmd->stage != 0) {
		smu_i2c_complete_command(cmd, fail);
		return;
	}

	DPRINTK("SMU: going to stage 1\n");

	/* Ok, initial command complete, now poll status */
	scmd->reply_buf = cmd->pdata;
	scmd->reply_len = sizeof(cmd->pdata);
	scmd->data_buf = cmd->pdata;
	scmd->data_len = 1;
	cmd->pdata[0] = 0;
	cmd->stage = 1;
	cmd->retries = 20;
	smu_queue_cmd(scmd);
}


int smu_queue_i2c(struct smu_i2c_cmd *cmd)
{
	unsigned long flags;

	if (smu == NULL)
		return -ENODEV;

	/* Fill most fields of scmd */
	cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
	cmd->scmd.done = smu_i2c_low_completion;
	cmd->scmd.misc = cmd;
	cmd->scmd.reply_buf = cmd->pdata;
	cmd->scmd.reply_len = sizeof(cmd->pdata);
	cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
	cmd->scmd.status = 1;
	cmd->stage = 0;
	cmd->pdata[0] = 0xff;
	cmd->retries = 20;
	cmd->status = 1;

	/* Check transfer type, sanitize some "info" fields
	 * based on transfer type and do more checking
	 */
	cmd->info.caddr = cmd->info.devaddr;
	cmd->read = cmd->info.devaddr & 0x01;
	switch(cmd->info.type) {
	case SMU_I2C_TRANSFER_SIMPLE:
		memset(&cmd->info.sublen, 0, 4);
		break;
	case SMU_I2C_TRANSFER_COMBINED:
		cmd->info.devaddr &= 0xfe;
	case SMU_I2C_TRANSFER_STDSUB:
		if (cmd->info.sublen > 3)
			return -EINVAL;
		break;
	default:
		return -EINVAL;
	}

	/* Finish setting up command based on transfer direction
	 */
	if (cmd->read) {
		if (cmd->info.datalen > SMU_I2C_READ_MAX)
			return -EINVAL;
		memset(cmd->info.data, 0xff, cmd->info.datalen);
		cmd->scmd.data_len = 9;
	} else {
		if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
			return -EINVAL;
		cmd->scmd.data_len = 9 + cmd->info.datalen;
	}

	DPRINTK("SMU: i2c enqueuing command\n");
	DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
		cmd->read ? "read" : "write", cmd->info.datalen,
		cmd->info.bus, cmd->info.caddr,
		cmd->info.subaddr[0], cmd->info.type);


	/* Enqueue command in i2c list, and if empty, enqueue also in
	 * main command list
	 */
	spin_lock_irqsave(&smu->lock, flags);
	if (smu->cmd_i2c_cur == NULL) {
		smu->cmd_i2c_cur = cmd;
		list_add_tail(&cmd->scmd.link, &smu->cmd_list);
		if (smu->cmd_cur == NULL)
			smu_start_cmd();
	} else
		list_add_tail(&cmd->link, &smu->cmd_i2c_list);
	spin_unlock_irqrestore(&smu->lock, flags);

	return 0;
}

/*
 * Handling of "partitions"
 */

static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
{
	DECLARE_COMPLETION_ONSTACK(comp);
	unsigned int chunk;
	struct smu_cmd cmd;
	int rc;
	u8 params[8];

	/* We currently use a chunk size of 0xe. We could check the
	 * SMU firmware version and use bigger sizes though
	 */
	chunk = 0xe;

	while (len) {
		unsigned int clen = min(len, chunk);

		cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
		cmd.data_len = 7;
		cmd.data_buf = params;
		cmd.reply_len = chunk;
		cmd.reply_buf = dest;
		cmd.done = smu_done_complete;
		cmd.misc = &comp;
		params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
		params[1] = 0x4;
		*((u32 *)&params[2]) = addr;
		params[6] = clen;

		rc = smu_queue_cmd(&cmd);
		if (rc)
			return rc;
		wait_for_completion(&comp);
		if (cmd.status != 0)
			return rc;
		if (cmd.reply_len != clen) {
			printk(KERN_DEBUG "SMU: short read in "
			       "smu_read_datablock, got: %d, want: %d\n",
			       cmd.reply_len, clen);
			return -EIO;
		}
		len -= clen;
		addr += clen;
		dest += clen;
	}
	return 0;
}

static struct smu_sdbp_header *smu_create_sdb_partition(int id)
{
	DECLARE_COMPLETION_ONSTACK(comp);
	struct smu_simple_cmd cmd;
	unsigned int addr, len, tlen;
	struct smu_sdbp_header *hdr;
	struct property *prop;

	/* First query the partition info */
	DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
	smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
			 smu_done_complete, &comp,
			 SMU_CMD_PARTITION_LATEST, id);
	wait_for_completion(&comp);
	DPRINTK("SMU: done, status: %d, reply_len: %d\n",
		cmd.cmd.status, cmd.cmd.reply_len);

	/* Partition doesn't exist (or other error) */
	if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
		return NULL;

	/* Fetch address and length from reply */
	addr = *((u16 *)cmd.buffer);
	len = cmd.buffer[3] << 2;
	/* Calucluate total length to allocate, including the 17 bytes
	 * for "sdb-partition-XX" that we append at the end of the buffer
	 */
	tlen = sizeof(struct property) + len + 18;

	prop = kzalloc(tlen, GFP_KERNEL);
	if (prop == NULL)
		return NULL;
	hdr = (struct smu_sdbp_header *)(prop + 1);
	prop->name = ((char *)prop) + tlen - 18;
	sprintf(prop->name, "sdb-partition-%02x", id);
	prop->length = len;
	prop->value = hdr;
	prop->next = NULL;

	/* Read the datablock */
	if (smu_read_datablock((u8 *)hdr, addr, len)) {
		printk(KERN_DEBUG "SMU: datablock read failed while reading "
		       "partition %02x !\n", id);
		goto failure;
	}

	/* Got it, check a few things and create the property */
	if (hdr->id != id) {
		printk(KERN_DEBUG "SMU: Reading partition %02x and got "
		       "%02x !\n", id, hdr->id);
		goto failure;
	}
	if (prom_add_property(smu->of_node, prop)) {
		printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
		       "property !\n", id);
		goto failure;
	}

	return hdr;
 failure:
	kfree(prop);
	return NULL;
}

/* Note: Only allowed to return error code in pointers (using ERR_PTR)
 * when interruptible is 1
 */
const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
		unsigned int *size, int interruptible)
{
	char pname[32];
	const struct smu_sdbp_header *part;

	if (!smu)
		return NULL;

	sprintf(pname, "sdb-partition-%02x", id);

	DPRINTK("smu_get_sdb_partition(%02x)\n", id);

	if (interruptible) {
		int rc;
		rc = mutex_lock_interruptible(&smu_part_access);
		if (rc)
			return ERR_PTR(rc);
	} else
		mutex_lock(&smu_part_access);

	part = of_get_property(smu->of_node, pname, size);
	if (part == NULL) {
		DPRINTK("trying to extract from SMU ...\n");
		part = smu_create_sdb_partition(id);
		if (part != NULL && size)
			*size = part->len << 2;
	}
	mutex_unlock(&smu_part_access);
	return part;
}

const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
{
	return __smu_get_sdb_partition(id, size, 0);
}
EXPORT_SYMBOL(smu_get_sdb_partition);


/*
 * Userland driver interface
 */


static LIST_HEAD(smu_clist);
static DEFINE_SPINLOCK(smu_clist_lock);

enum smu_file_mode {
	smu_file_commands,
	smu_file_events,
	smu_file_closing
};

struct smu_private
{
	struct list_head	list;
	enum smu_file_mode	mode;
	int			busy;
	struct smu_cmd		cmd;
	spinlock_t		lock;
	wait_queue_head_t	wait;
	u8			buffer[SMU_MAX_DATA];
};


static int smu_open(struct inode *inode, struct file *file)
{
	struct smu_private *pp;
	unsigned long flags;

	pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
	if (pp == 0)
		return -ENOMEM;
	spin_lock_init(&pp->lock);
	pp->mode = smu_file_commands;
	init_waitqueue_head(&pp->wait);

	spin_lock_irqsave(&smu_clist_lock, flags);
	list_add(&pp->list, &smu_clist);
	spin_unlock_irqrestore(&smu_clist_lock, flags);
	file->private_data = pp;

	return 0;
}


static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
{
	struct smu_private *pp = misc;

	wake_up_all(&pp->wait);
}


static ssize_t smu_write(struct file *file, const char __user *buf,
			 size_t count, loff_t *ppos)
{
	struct smu_private *pp = file->private_data;
	unsigned long flags;
	struct smu_user_cmd_hdr hdr;
	int rc = 0;

	if (pp->busy)
		return -EBUSY;
	else if (copy_from_user(&hdr, buf, sizeof(hdr)))
		return -EFAULT;
	else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
		pp->mode = smu_file_events;
		return 0;
	} else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
		const struct smu_sdbp_header *part;
		part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
		if (part == NULL)
			return -EINVAL;
		else if (IS_ERR(part))
			return PTR_ERR(part);
		return 0;
	} else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
		return -EINVAL;
	else if (pp->mode != smu_file_commands)
		return -EBADFD;
	else if (hdr.data_len > SMU_MAX_DATA)
		return -EINVAL;

	spin_lock_irqsave(&pp->lock, flags);
	if (pp->busy) {
		spin_unlock_irqrestore(&pp->lock, flags);
		return -EBUSY;
	}
	pp->busy = 1;
	pp->cmd.status = 1;
	spin_unlock_irqrestore(&pp->lock, flags);

	if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
		pp->busy = 0;
		return -EFAULT;
	}

	pp->cmd.cmd = hdr.cmd;
	pp->cmd.data_len = hdr.data_len;
	pp->cmd.reply_len = SMU_MAX_DATA;
	pp->cmd.data_buf = pp->buffer;
	pp->cmd.reply_buf = pp->buffer;
	pp->cmd.done = smu_user_cmd_done;
	pp->cmd.misc = pp;
	rc = smu_queue_cmd(&pp->cmd);
	if (rc < 0)
		return rc;
	return count;
}


static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
				char __user *buf, size_t count)
{
	DECLARE_WAITQUEUE(wait, current);
	struct smu_user_reply_hdr hdr;
	unsigned long flags;
	int size, rc = 0;

	if (!pp->busy)
		return 0;
	if (count < sizeof(struct smu_user_reply_hdr))
		return -EOVERFLOW;
	spin_lock_irqsave(&pp->lock, flags);
	if (pp->cmd.status == 1) {
		if (file->f_flags & O_NONBLOCK)
			return -EAGAIN;
		add_wait_queue(&pp->wait, &wait);
		for (;;) {
			set_current_state(TASK_INTERRUPTIBLE);
			rc = 0;
			if (pp->cmd.status != 1)
				break;
			rc = -ERESTARTSYS;
			if (signal_pending(current))
				break;
			spin_unlock_irqrestore(&pp->lock, flags);
			schedule();
			spin_lock_irqsave(&pp->lock, flags);
		}
		set_current_state(TASK_RUNNING);
		remove_wait_queue(&pp->wait, &wait);
	}
	spin_unlock_irqrestore(&pp->lock, flags);
	if (rc)
		return rc;
	if (pp->cmd.status != 0)
		pp->cmd.reply_len = 0;
	size = sizeof(hdr) + pp->cmd.reply_len;
	if (count < size)
		size = count;
	rc = size;
	hdr.status = pp->cmd.status;
	hdr.reply_len = pp->cmd.reply_len;
	if (copy_to_user(buf, &hdr, sizeof(hdr)))
		return -EFAULT;
	size -= sizeof(hdr);
	if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
		return -EFAULT;
	pp->busy = 0;

	return rc;
}


static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
			       char __user *buf, size_t count)
{
	/* Not implemented */
	msleep_interruptible(1000);
	return 0;
}


static ssize_t smu_read(struct file *file, char __user *buf,
			size_t count, loff_t *ppos)
{
	struct smu_private *pp = file->private_data;

	if (pp->mode == smu_file_commands)
		return smu_read_command(file, pp, buf, count);
	if (pp->mode == smu_file_events)
		return smu_read_events(file, pp, buf, count);

	return -EBADFD;
}

static unsigned int smu_fpoll(struct file *file, poll_table *wait)
{
	struct smu_private *pp = file->private_data;
	unsigned int mask = 0;
	unsigned long flags;

	if (pp == 0)
		return 0;

	if (pp->mode == smu_file_commands) {
		poll_wait(file, &pp->wait, wait);

		spin_lock_irqsave(&pp->lock, flags);
		if (pp->busy && pp->cmd.status != 1)
			mask |= POLLIN;
		spin_unlock_irqrestore(&pp->lock, flags);
	} if (pp->mode == smu_file_events) {
		/* Not yet implemented */
	}
	return mask;
}

static int smu_release(struct inode *inode, struct file *file)
{
	struct smu_private *pp = file->private_data;
	unsigned long flags;
	unsigned int busy;

	if (pp == 0)
		return 0;

	file->private_data = NULL;

	/* Mark file as closing to avoid races with new request */
	spin_lock_irqsave(&pp->lock, flags);
	pp->mode = smu_file_closing;
	busy = pp->busy;

	/* Wait for any pending request to complete */
	if (busy && pp->cmd.status == 1) {
		DECLARE_WAITQUEUE(wait, current);

		add_wait_queue(&pp->wait, &wait);
		for (;;) {
			set_current_state(TASK_UNINTERRUPTIBLE);
			if (pp->cmd.status != 1)
				break;
			spin_unlock_irqrestore(&pp->lock, flags);
			schedule();
			spin_lock_irqsave(&pp->lock, flags);
		}
		set_current_state(TASK_RUNNING);
		remove_wait_queue(&pp->wait, &wait);
	}
	spin_unlock_irqrestore(&pp->lock, flags);

	spin_lock_irqsave(&smu_clist_lock, flags);
	list_del(&pp->list);
	spin_unlock_irqrestore(&smu_clist_lock, flags);
	kfree(pp);

	return 0;
}


static const struct file_operations smu_device_fops = {
	.llseek		= no_llseek,
	.read		= smu_read,
	.write		= smu_write,
	.poll		= smu_fpoll,
	.open		= smu_open,
	.release	= smu_release,
};

static struct miscdevice pmu_device = {
	MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
};

static int smu_device_init(void)
{
	if (!smu)
		return -ENODEV;
	if (misc_register(&pmu_device) < 0)
		printk(KERN_ERR "via-pmu: cannot register misc device.\n");
	return 0;
}
device_initcall(smu_device_init);