drivers/fsi: Add SBEFIFO and OCC client drivers

577 lines not on this page · raw message

index 6ba190a..fed3739 100644
@@ -19,6 +19,7 @@
 #include <linux/kernel.h>
 #include <linux/kref.h>
 #include <linux/list.h>
+#include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/poll.h>
 #include <linux/sched.h>

@@ -54,6 +55,7 @@
 struct sbefifo {
 	struct timer_list poll_timer;
 	struct fsi_device *fsi_dev;
+	struct miscdevice mdev;
 	wait_queue_head_t wait;
 	struct list_head xfrs;
 	struct kref kref;

@@ -256,6 +258,99 @@ static void sbefifo_put(struct sbefifo *sbefifo)
 	kref_put(&sbefifo->kref, sbefifo_free);
 }
 
+static struct sbefifo_xfr *sbefifo_enq_xfr(struct sbefifo_client *client)
+{
+	struct sbefifo *sbefifo = client->dev;
+	struct sbefifo_xfr *xfr;
+
+	if (READ_ONCE(sbefifo->rc))
+		return ERR_PTR(sbefifo->rc);
+
+	xfr = kzalloc(sizeof(*xfr), GFP_KERNEL);
+	if (!xfr)
+		return ERR_PTR(-ENOMEM);
+
+	xfr->rbuf = &client->rbuf;
+	xfr->wbuf = &client->wbuf;
+	list_add_tail(&xfr->xfrs, &sbefifo->xfrs);
+	list_add_tail(&xfr->client, &client->xfrs);
+
+	return xfr;
+}
+
+static bool sbefifo_xfr_rsp_pending(struct sbefifo_client *client)
+{
+	struct sbefifo_xfr *xfr = list_first_entry_or_null(&client->xfrs,
+							   struct sbefifo_xfr,
+							   client);
+
+	if (xfr && test_bit(SBEFIFO_XFR_RESP_PENDING, &xfr->flags))
+		return true;
+
+	return false;
+}
+
+static struct sbefifo_client *sbefifo_new_client(struct sbefifo *sbefifo)
+{
+	struct sbefifo_client *client;
+
+	client = kzalloc(sizeof(*client), GFP_KERNEL);
+	if (!client)
+		return NULL;
+
+	kref_init(&client->kref);
+	client->dev = sbefifo;
+	sbefifo_buf_init(&client->rbuf);
+	sbefifo_buf_init(&client->wbuf);
+	INIT_LIST_HEAD(&client->xfrs);
+
+	sbefifo_get(sbefifo);
+
+	return client;
+}
+
+static void sbefifo_client_release(struct kref *kref)
+{
+	struct sbefifo *sbefifo;
+	struct sbefifo_client *client;
+	struct sbefifo_xfr *xfr, *tmp;
+
+	client = container_of(kref, struct sbefifo_client, kref);
+	sbefifo = client->dev;
+
+	if (!READ_ONCE(sbefifo->rc)) {
+		list_for_each_entry_safe(xfr, tmp, &client->xfrs, client) {
+			if (test_bit(SBEFIFO_XFR_COMPLETE, &xfr->flags)) {
+				list_del(&xfr->client);
+				kfree(xfr);
+				continue;
+			}
+
+			/*
+			 * The client left with pending or running xfrs.
+			 * Cancel them.
+			 */
+			set_bit(SBEFIFO_XFR_CANCEL, &xfr->flags);
+			sbefifo_get(sbefifo);
+			if (mod_timer(&client->dev->poll_timer, jiffies))
+				sbefifo_put(sbefifo);
+		}
+	}
+
+	sbefifo_put(sbefifo);
+	kfree(client);
+}
+
+static void sbefifo_get_client(struct sbefifo_client *client)
+{
+	kref_get(&client->kref);
+}
+
+static void sbefifo_put_client(struct sbefifo_client *client)
+{
+	kref_put(&client->kref, sbefifo_client_release);
+}
+
 static struct sbefifo_xfr *sbefifo_next_xfr(struct sbefifo *sbefifo)
 {
 	struct sbefifo_xfr *xfr, *tmp;

@@ -430,6 +525,252 @@ static void sbefifo_poll_timer(unsigned long data)
 	spin_unlock_irqrestore(&sbefifo->lock, flags);
 }
 
+static int sbefifo_open(struct inode *inode, struct file *file)
+{
+	struct sbefifo *sbefifo = container_of(file->private_data,
+					       struct sbefifo, mdev);
+	struct sbefifo_client *client;
+	int ret;
+
+	ret = READ_ONCE(sbefifo->rc);
+	if (ret)
+		return ret;
+
+	client = sbefifo_new_client(sbefifo);
+	if (!client)
+		return -ENOMEM;
+
+	file->private_data = client;
+
+	return 0;
+}
+
+static unsigned int sbefifo_poll(struct file *file, poll_table *wait)
+{
+	struct sbefifo_client *client = file->private_data;
+	struct sbefifo *sbefifo = client->dev;
+	unsigned int mask = 0;
+
+	poll_wait(file, &sbefifo->wait, wait);
+
+	if (READ_ONCE(sbefifo->rc))
+		mask |= POLLERR;
+
+	if (sbefifo_buf_nbreadable(&client->rbuf))
+		mask |= POLLIN;
+
+	if (sbefifo_buf_nbwriteable(&client->wbuf))
+		mask |= POLLOUT;
+
+	return mask;
+}
+
+static bool sbefifo_read_ready(struct sbefifo *sbefifo,
+			       struct sbefifo_client *client, size_t *n,
+			       size_t *ret)
+{
+	struct sbefifo_xfr *xfr = list_first_entry_or_null(&client->xfrs,
+							   struct sbefifo_xfr,
+							   client);
+
+	*n = sbefifo_buf_nbreadable(&client->rbuf);
+	*ret = READ_ONCE(sbefifo->rc);
+
+	return *ret || *n ||
+		(xfr && test_bit(SBEFIFO_XFR_COMPLETE, &xfr->flags));
+}
+
+static ssize_t sbefifo_read(struct file *file, char __user *buf, size_t len,
+			    loff_t *offset)
+{
+	struct sbefifo_client *client = file->private_data;
+	struct sbefifo *sbefifo = client->dev;
+	struct sbefifo_xfr *xfr;
+	size_t n;
+	ssize_t ret = 0;
+
+	if ((len >> 2) << 2 != len)
+		return -EINVAL;
+
+	if ((file->f_flags & O_NONBLOCK) && !sbefifo_xfr_rsp_pending(client))
+		return -EAGAIN;
+
+	sbefifo_get_client(client);
+	if (wait_event_interruptible(sbefifo->wait,
+				     sbefifo_read_ready(sbefifo, client, &n,
+							&ret))) {
+		ret = -ERESTARTSYS;
+		goto out;
+	}
+
+	if (ret) {
+		INIT_LIST_HEAD(&client->xfrs);
+		goto out;
+	}
+
+	n = min_t(size_t, n, len);
+
+	if (copy_to_user(buf, READ_ONCE(client->rbuf.rpos), n)) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	if (sbefifo_buf_readnb(&client->rbuf, n)) {
+		xfr = list_first_entry_or_null(&client->xfrs,
+					       struct sbefifo_xfr, client);
+		if (!xfr) {
+			/* should be impossible to not have an xfr here */
+			WARN_ONCE(1, "no xfr in queue");
+			ret = -EPROTO;
+			goto out;
+		}
+
+		if (!test_bit(SBEFIFO_XFR_COMPLETE, &xfr->flags)) {
+			/* Fill the read buffer back up. */
+			sbefifo_get(sbefifo);
+			if (mod_timer(&client->dev->poll_timer, jiffies))
+				sbefifo_put(sbefifo);
+		} else {
+			list_del(&xfr->client);
+			kfree(xfr);
+			wake_up_interruptible(&sbefifo->wait);
+		}
+	}
+
+	ret = n;
+
+out:
+	sbefifo_put_client(client);
+	return ret;
+}
+
+static bool sbefifo_write_ready(struct sbefifo *sbefifo,
+				struct sbefifo_xfr *xfr,
+				struct sbefifo_client *client, size_t *n)
+{
+	struct sbefifo_xfr *next = list_first_entry_or_null(&client->xfrs,
+							    struct sbefifo_xfr,
+							    client);
+
+	*n = sbefifo_buf_nbwriteable(&client->wbuf);
+	return READ_ONCE(sbefifo->rc) || (next == xfr && *n);
+}
+
+static ssize_t sbefifo_write(struct file *file, const char __user *buf,
+			     size_t len, loff_t *offset)
+{
+	unsigned long flags;
+	struct sbefifo_client *client = file->private_data;
+	struct sbefifo *sbefifo = client->dev;
+	struct sbefifo_xfr *xfr;
+	ssize_t ret = 0;
+	size_t n;
+
+	if ((len >> 2) << 2 != len)
+		return -EINVAL;
+
+	if (!len)
+		return 0;
+
+	sbefifo_get_client(client);
+	n = sbefifo_buf_nbwriteable(&client->wbuf);
+
+	spin_lock_irqsave(&sbefifo->lock, flags);
+	xfr = sbefifo_next_xfr(sbefifo);	/* next xfr to be executed */
+
+	if ((file->f_flags & O_NONBLOCK) && xfr && n < len) {
+		spin_unlock_irqrestore(&sbefifo->lock, flags);
+		ret = -EAGAIN;
+		goto out;
+	}
+
+	xfr = sbefifo_enq_xfr(client);		/* this xfr queued up */
+	if (IS_ERR(xfr)) {
+		spin_unlock_irqrestore(&sbefifo->lock, flags);
+		ret = PTR_ERR(xfr);
+		goto out;
+	}
+
+	spin_unlock_irqrestore(&sbefifo->lock, flags);
+
+	/*
+	 * Partial writes are not really allowed in that EOT is sent exactly
+	 * once per write.
+	 */
+	while (len) {
+		if (wait_event_interruptible(sbefifo->wait,
+					     sbefifo_write_ready(sbefifo, xfr,
+								 client,
+								 &n))) {
+			set_bit(SBEFIFO_XFR_CANCEL, &xfr->flags);
+			sbefifo_get(sbefifo);
+			if (mod_timer(&sbefifo->poll_timer, jiffies))
+				sbefifo_put(sbefifo);
+
+			ret = -ERESTARTSYS;
+			goto out;
+		}
+
+		if (sbefifo->rc) {
+			INIT_LIST_HEAD(&client->xfrs);
+			ret = sbefifo->rc;
+			goto out;
+		}
+
+		n = min_t(size_t, n, len);
+
+		if (copy_from_user(READ_ONCE(client->wbuf.wpos), buf, n)) {
+			set_bit(SBEFIFO_XFR_CANCEL, &xfr->flags);
+			sbefifo_get(sbefifo);
+			if (mod_timer(&sbefifo->poll_timer, jiffies))
+				sbefifo_put(sbefifo);
+			ret = -EFAULT;
+			goto out;
+		}
+
+		buf += n;
+
+		sbefifo_buf_wrotenb(&client->wbuf, n);
+		len -= n;
+		ret += n;
+
+		/*
+		 * Set this before starting timer to avoid race condition on
+		 * this flag with the timer function writer.
+		 */
+		if (!len)
+			set_bit(SBEFIFO_XFR_WRITE_DONE, &xfr->flags);
+
+		/* Drain the write buffer. */
+		sbefifo_get(sbefifo);
+		if (mod_timer(&client->dev->poll_timer, jiffies))
+			sbefifo_put(sbefifo);
+	}
+
+out:
+	sbefifo_put_client(client);
+	return ret;
+}
+
+static int sbefifo_release(struct inode *inode, struct file *file)
+{
+	struct sbefifo_client *client = file->private_data;
+	struct sbefifo *sbefifo = client->dev;
+
+	sbefifo_put_client(client);
+
+	return READ_ONCE(sbefifo->rc);
+}
+
+static const struct file_operations sbefifo_fops = {
+	.owner		= THIS_MODULE,
+	.open		= sbefifo_open,
+	.read		= sbefifo_read,
+	.write		= sbefifo_write,
+	.poll		= sbefifo_poll,
+	.release	= sbefifo_release,
+};
+
 static int sbefifo_request_reset(struct sbefifo *sbefifo)
 {
 	int ret;

@@ -504,6 +845,18 @@ static int sbefifo_probe(struct device *dev)
 	setup_timer(&sbefifo->poll_timer, sbefifo_poll_timer,
 		    (unsigned long)sbefifo);
 
+	sbefifo->mdev.minor = MISC_DYNAMIC_MINOR;
+	sbefifo->mdev.fops = &sbefifo_fops;
+	sbefifo->mdev.name = sbefifo->name;
+	sbefifo->mdev.parent = dev;
+	ret = misc_register(&sbefifo->mdev);
+	if (ret) {
+		dev_err(dev, "failed to register miscdevice: %d\n", ret);
+		ida_simple_remove(&sbefifo_ida, sbefifo->idx);
+		sbefifo_put(sbefifo);
+		return ret;
+	}
+
 	dev_set_drvdata(dev, sbefifo);
 
 	return 0;

@@ -529,6 +882,8 @@ static int sbefifo_remove(struct device *dev)
 
 	wake_up_all(&sbefifo->wait);
 
+	misc_deregister(&sbefifo->mdev);
+
 	ida_simple_remove(&sbefifo_ida, sbefifo->idx);
 
 	if (del_timer_sync(&sbefifo->poll_timer))

index fed3739..b622c70 100644
@@ -15,12 +15,16 @@
 #include <linux/errno.h>
 #include <linux/fs.h>
 #include <linux/fsi.h>
+#include <linux/fsi-sbefifo.h>
 #include <linux/idr.h>
 #include <linux/kernel.h>
 #include <linux/kref.h>
 #include <linux/list.h>
 #include <linux/miscdevice.h>
 #include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
 #include <linux/poll.h>
 #include <linux/sched.h>
 #include <linux/slab.h>

@@ -92,6 +96,7 @@ struct sbefifo_client {
 	struct list_head xfrs;
 	struct sbefifo *dev;
 	struct kref kref;
+	unsigned long f_flags;
 };
 
 static DEFINE_IDA(sbefifo_ida);

@@ -541,6 +546,7 @@ static int sbefifo_open(struct inode *inode, struct file *file)
 		return -ENOMEM;
 
 	file->private_data = client;
+	client->f_flags = file->f_flags;
 
 	return 0;
 }

@@ -580,10 +586,9 @@ static bool sbefifo_read_ready(struct sbefifo *sbefifo,
 		(xfr && test_bit(SBEFIFO_XFR_COMPLETE, &xfr->flags));
 }
 
-static ssize_t sbefifo_read(struct file *file, char __user *buf, size_t len,
-			    loff_t *offset)
+static ssize_t sbefifo_read_common(struct sbefifo_client *client,
+				   char __user *ubuf, char *kbuf, size_t len)
 {
-	struct sbefifo_client *client = file->private_data;
 	struct sbefifo *sbefifo = client->dev;
 	struct sbefifo_xfr *xfr;
 	size_t n;

@@ -592,7 +597,7 @@ static ssize_t sbefifo_read(struct file *file, char __user *buf, size_t len,
 	if ((len >> 2) << 2 != len)
 		return -EINVAL;
 
-	if ((file->f_flags & O_NONBLOCK) && !sbefifo_xfr_rsp_pending(client))
+	if ((client->f_flags & O_NONBLOCK) && !sbefifo_xfr_rsp_pending(client))
 		return -EAGAIN;
 
 	sbefifo_get_client(client);

@@ -610,9 +615,13 @@ static ssize_t sbefifo_read(struct file *file, char __user *buf, size_t len,
 
 	n = min_t(size_t, n, len);
 
-	if (copy_to_user(buf, READ_ONCE(client->rbuf.rpos), n)) {
-		ret = -EFAULT;
-		goto out;
+	if (ubuf) {
+		if (copy_to_user(ubuf, READ_ONCE(client->rbuf.rpos), n)) {
+			ret = -EFAULT;
+			goto out;
+		}
+	} else {
+		memcpy(kbuf, READ_ONCE(client->rbuf.rpos), n);
 	}
 
 	if (sbefifo_buf_readnb(&client->rbuf, n)) {

@@ -644,6 +653,14 @@ static ssize_t sbefifo_read(struct file *file, char __user *buf, size_t len,
 	return ret;
 }
 
+static ssize_t sbefifo_read(struct file *file, char __user *buf, size_t len,
+			    loff_t *offset)
+{
+	struct sbefifo_client *client = file->private_data;
+
+	return sbefifo_read_common(client, buf, NULL, len);
+}
+
 static bool sbefifo_write_ready(struct sbefifo *sbefifo,
 				struct sbefifo_xfr *xfr,
 				struct sbefifo_client *client, size_t *n)

@@ -656,11 +673,11 @@ static bool sbefifo_write_ready(struct sbefifo *sbefifo,
 	return READ_ONCE(sbefifo->rc) || (next == xfr && *n);
 }
 
-static ssize_t sbefifo_write(struct file *file, const char __user *buf,
-			     size_t len, loff_t *offset)
+static ssize_t sbefifo_write_common(struct sbefifo_client *client,
+				    const char __user *ubuf, const char *kbuf,
+				    size_t len)
 {
 	unsigned long flags;
-	struct sbefifo_client *client = file->private_data;
 	struct sbefifo *sbefifo = client->dev;
 	struct sbefifo_xfr *xfr;
 	ssize_t ret = 0;

@@ -678,7 +695,7 @@ static ssize_t sbefifo_write(struct file *file, const char __user *buf,
 	spin_lock_irqsave(&sbefifo->lock, flags);
 	xfr = sbefifo_next_xfr(sbefifo);	/* next xfr to be executed */
 
-	if ((file->f_flags & O_NONBLOCK) && xfr && n < len) {
+	if ((client->f_flags & O_NONBLOCK) && xfr && n < len) {
 		spin_unlock_irqrestore(&sbefifo->lock, flags);
 		ret = -EAGAIN;
 		goto out;

@@ -719,16 +736,22 @@ static ssize_t sbefifo_write(struct file *file, const char __user *buf,
 
 		n = min_t(size_t, n, len);
 
-		if (copy_from_user(READ_ONCE(client->wbuf.wpos), buf, n)) {
-			set_bit(SBEFIFO_XFR_CANCEL, &xfr->flags);
-			sbefifo_get(sbefifo);
-			if (mod_timer(&sbefifo->poll_timer, jiffies))
-				sbefifo_put(sbefifo);
-			ret = -EFAULT;
-			goto out;
-		}
+		if (ubuf) {
+			if (copy_from_user(READ_ONCE(client->wbuf.wpos), ubuf,
+					   n)) {
+				set_bit(SBEFIFO_XFR_CANCEL, &xfr->flags);
+				sbefifo_get(sbefifo);
+				if (mod_timer(&sbefifo->poll_timer, jiffies))
+					sbefifo_put(sbefifo);
+				ret = -EFAULT;
+				goto out;
+			}
 
-		buf += n;
+			ubuf += n;
+		} else {
+			memcpy(READ_ONCE(client->wbuf.wpos), kbuf, n);
+			kbuf += n;
+		}
 
 		sbefifo_buf_wrotenb(&client->wbuf, n);
 		len -= n;

@@ -752,6 +775,14 @@ static ssize_t sbefifo_write(struct file *file, const char __user *buf,
 	return ret;
 }
 
+static ssize_t sbefifo_write(struct file *file, const char __user *buf,
+			     size_t len, loff_t *offset)
+{
+	struct sbefifo_client *client = file->private_data;
+
+	return sbefifo_write_common(client, buf, NULL, len);
+}
+
 static int sbefifo_release(struct inode *inode, struct file *file)
 {
 	struct sbefifo_client *client = file->private_data;

@@ -771,6 +802,56 @@ static int sbefifo_release(struct inode *inode, struct file *file)
 	.release	= sbefifo_release,
 };
 
+struct sbefifo_client *sbefifo_drv_open(struct device *dev,
+					unsigned long flags)
+{
+	struct sbefifo_client *client;
+	struct sbefifo *sbefifo = dev_get_drvdata(dev);
+
+	if (!sbefifo)
+		return NULL;
+
+	client = sbefifo_new_client(sbefifo);
+	if (client)
+		client->f_flags = flags;
+
+	return client;
+}
+EXPORT_SYMBOL_GPL(sbefifo_drv_open);
+
+int sbefifo_drv_read(struct sbefifo_client *client, char *buf, size_t len)
+{
+	return sbefifo_read_common(client, NULL, buf, len);
+}
+EXPORT_SYMBOL_GPL(sbefifo_drv_read);
+
+int sbefifo_drv_write(struct sbefifo_client *client, const char *buf,
+		      size_t len)
+{
+	return sbefifo_write_common(client, NULL, buf, len);
+}
+EXPORT_SYMBOL_GPL(sbefifo_drv_write);
+
+void sbefifo_drv_release(struct sbefifo_client *client)
+{
+	if (!client)
+		return;
+
+	sbefifo_put_client(client);
+}
+EXPORT_SYMBOL_GPL(sbefifo_drv_release);
+
+static int sbefifo_unregister_child(struct device *dev, void *data)
+{
+	struct platform_device *child = to_platform_device(dev);
+
+	of_device_unregister(child);
+	if (dev->of_node)
+		of_node_clear_flag(dev->of_node, OF_POPULATED);
+
+	return 0;
+}
+
 static int sbefifo_request_reset(struct sbefifo *sbefifo)
 {
 	int ret;

@@ -805,8 +886,11 @@ static int sbefifo_probe(struct device *dev)
 {
 	struct fsi_device *fsi_dev = to_fsi_dev(dev);
 	struct sbefifo *sbefifo;
+	struct device_node *np;
+	struct platform_device *child;
+	char child_name[32];
 	u32 up, down;
-	int ret;
+	int ret, child_idx = 0;
 
 	dev_dbg(dev, "Found sbefifo device\n");
 	sbefifo = kzalloc(sizeof(*sbefifo), GFP_KERNEL);

@@ -857,6 +941,16 @@ static int sbefifo_probe(struct device *dev)
 		return ret;
 	}
 
+	/* create platform devs for dts child nodes (occ, etc) */
+	for_each_available_child_of_node(dev->of_node, np) {
+		snprintf(child_name, sizeof(child_name), "%s-dev%d",
+			 sbefifo->name, child_idx++);
+		child = of_platform_device_create(np, child_name, dev);
+		if (!child)
+			dev_warn(dev, "failed to create child %s dev\n",
+				 child_name);
+	}
+
 	dev_set_drvdata(dev, sbefifo);
 
 	return 0;

@@ -883,6 +977,7 @@ static int sbefifo_remove(struct device *dev)
 	wake_up_all(&sbefifo->wait);
 
 	misc_deregister(&sbefifo->mdev);
+	device_for_each_child(dev, NULL, sbefifo_unregister_child);
 
 	ida_simple_remove(&sbefifo_ida, sbefifo->idx);
 

new file mode 100644
index 0000000..8e55891
@@ -0,0 +1,30 @@
+/*
+ * SBEFIFO FSI Client device driver
+ *
+ * Copyright (C) IBM Corporation 2017
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERGCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef LINUX_FSI_SBEFIFO_H
+#define LINUX_FSI_SBEFIFO_H
+
+struct device;
+struct sbefifo_client;
+
+extern struct sbefifo_client *sbefifo_drv_open(struct device *dev,
+					       unsigned long flags);
+extern int sbefifo_drv_read(struct sbefifo_client *client, char *buf,
+			    size_t len);
+extern int sbefifo_drv_write(struct sbefifo_client *client, const char *buf,
+			     size_t len);
+extern void sbefifo_drv_release(struct sbefifo_client *client);
+
+#endif /* LINUX_FSI_SBEFIFO_H */

518 lines not on this page · raw message

index 99dbfa3..1aeb67d 100644
@@ -16,6 +16,7 @@
 #include <linux/idr.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
+#include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of.h>

@@ -40,6 +41,7 @@ struct occ {
 	struct device *sbefifo;
 	char name[32];
 	int idx;
+	struct miscdevice mdev;
 	struct list_head xfrs;
 	spinlock_t list_lock;		/* lock access to the xfrs list */
 	struct mutex occ_lock;		/* lock access to the hardware */

@@ -113,6 +115,29 @@ struct occ_client {
 
 static DEFINE_IDA(occ_ida);
 
+static int occ_enqueue_xfr(struct occ_xfr *xfr)
+{
+	int empty;
+	unsigned long flags;
+	struct occ_client *client = to_client(xfr);
+	struct occ *occ = client->occ;
+
+	if (occ->cancel)
+		return -ENODEV;
+
+	spin_lock_irqsave(&occ->list_lock, flags);
+
+	empty = list_empty(&occ->xfrs);
+	list_add_tail(&xfr->link, &occ->xfrs);
+
+	spin_unlock_irqrestore(&occ->list_lock, flags);
+
+	if (empty)
+		queue_work(occ_wq, &occ->work);
+
+	return 0;
+}
+
 static void occ_get_client(struct occ_client *client)
 {
 	kref_get(&client->kref);

@@ -131,6 +156,230 @@ static void occ_put_client(struct occ_client *client)
 	kref_put(&client->kref, occ_client_release);
 }
 
+static int occ_open(struct inode *inode, struct file *file)
+{
+	struct miscdevice *mdev = file->private_data;
+	struct occ *occ = to_occ(mdev);
+	struct occ_client *client = kzalloc(sizeof(*client), GFP_KERNEL);
+
+	if (!client)
+		return -ENOMEM;
+
+	client->occ = occ;
+	kref_init(&client->kref);
+	spin_lock_init(&client->lock);
+	init_waitqueue_head(&client->wait);
+
+	if (file->f_flags & O_NONBLOCK)
+		set_bit(CLIENT_NONBLOCKING, &client->flags);
+
+	file->private_data = client;
+
+	return 0;
+}
+
+static inline bool occ_read_ready(struct occ_xfr *xfr, struct occ *occ)
+{
+	return test_bit(XFR_COMPLETE, &xfr->flags) ||
+		test_bit(XFR_CANCELED, &xfr->flags) || occ->cancel;
+}
+
+static ssize_t occ_read(struct file *file, char __user *buf, size_t len,
+			loff_t *offset)
+{
+	int rc;
+	unsigned long flags;
+	size_t bytes;
+	struct occ_xfr *xfr;
+	struct occ *occ;
+	struct occ_client *client = file->private_data;
+
+	if (!client)
+		return -ENODEV;
+
+	if (len > OCC_SRAM_BYTES)
+		return -EINVAL;
+
+	occ_get_client(client);
+	xfr = &client->xfr;
+	occ = client->occ;
+
+	spin_lock_irqsave(&client->lock, flags);
+
+	if (!test_bit(CLIENT_XFR_PENDING, &client->flags)) {
+		/* we just finished reading all data, return 0 */
+		if (client->read_offset) {
+			rc = 0;
+			client->read_offset = 0;
+		} else {
+			rc = -ENOMSG;
+		}
+
+		goto done;
+	}
+
+	if (!test_bit(XFR_COMPLETE, &xfr->flags)) {
+		if (test_bit(CLIENT_NONBLOCKING, &client->flags)) {
+			rc = -EAGAIN;
+			goto done;
+		}
+
+		spin_unlock_irqrestore(&client->lock, flags);
+
+		rc = wait_event_interruptible(client->wait,
+					      occ_read_ready(xfr, occ));
+
+		spin_lock_irqsave(&client->lock, flags);
+
+		if (!test_bit(XFR_COMPLETE, &xfr->flags)) {
+			if (occ->cancel || test_bit(XFR_CANCELED, &xfr->flags))
+				rc = -ENODEV;
+			else
+				rc = -EINTR;
+
+			goto done;
+		}
+	}
+
+	if (xfr->rc) {
+		rc = xfr->rc;
+		goto done;
+	}
+
+	bytes = min(len, xfr->resp_data_length - client->read_offset);
+	if (copy_to_user(buf, &xfr->buf[client->read_offset], bytes)) {
+		rc = -EFAULT;
+		goto done;
+	}
+
+	client->read_offset += bytes;
+
+	/* xfr done */
+	if (client->read_offset == xfr->resp_data_length)
+		clear_bit(CLIENT_XFR_PENDING, &client->flags);
+
+	rc = bytes;
+
+done:
+	spin_unlock_irqrestore(&client->lock, flags);
+	occ_put_client(client);
+	return rc;
+}
+
+static ssize_t occ_write(struct file *file, const char __user *buf,
+			 size_t len, loff_t *offset)
+{
+	int rc;
+	unsigned long flags;
+	unsigned int i;
+	u16 data_length, checksum = 0;
+	struct occ_xfr *xfr;
+	struct occ_client *client = file->private_data;
+
+	if (!client)
+		return -ENODEV;
+
+	if (len > (OCC_CMD_DATA_BYTES + 3) || len < 3)
+		return -EINVAL;
+
+	occ_get_client(client);
+	xfr = &client->xfr;
+
+	spin_lock_irqsave(&client->lock, flags);
+
+	if (test_bit(CLIENT_XFR_PENDING, &client->flags)) {
+		rc = -EBUSY;
+		goto done;
+	}
+
+	memset(xfr, 0, sizeof(*xfr));	/* clear out the transfer */
+	xfr->buf[0] = 1;		/* occ sequence number */
+
+	/*
+	 * Assume user data follows the occ command format.
+	 * byte 0: command type
+	 * bytes 1-2: data length (msb first)
+	 * bytes 3-n: data
+	 */
+	if (copy_from_user(&xfr->buf[1], buf, len)) {
+		rc = -EFAULT;
+		goto done;
+	}
+
+	data_length = (xfr->buf[2] << 8) + xfr->buf[3];
+	if (data_length > OCC_CMD_DATA_BYTES) {
+		rc = -EINVAL;
+		goto done;
+	}
+
+	for (i = 0; i < data_length + 4; ++i)
+		checksum += xfr->buf[i];
+
+	xfr->buf[data_length + 4] = checksum >> 8;
+	xfr->buf[data_length + 5] = checksum & 0xFF;
+
+	xfr->cmd_data_length = data_length + 6;
+	client->read_offset = 0;
+
+	rc = occ_enqueue_xfr(xfr);
+	if (rc)
+		goto done;
+
+	set_bit(CLIENT_XFR_PENDING, &client->flags);
+	rc = len;
+
+done:
+	spin_unlock_irqrestore(&client->lock, flags);
+	occ_put_client(client);
+	return rc;
+}
+
+static int occ_release(struct inode *inode, struct file *file)
+{
+	unsigned long flags;
+	struct occ *occ;
+	struct occ_xfr *xfr;
+	struct occ_client *client = file->private_data;
+
+	if (!client)
+		return -ENODEV;
+
+	xfr = &client->xfr;
+	occ = client->occ;
+
+	spin_lock_irqsave(&client->lock, flags);
+
+	set_bit(XFR_CANCELED, &xfr->flags);
+	if (!test_bit(CLIENT_XFR_PENDING, &client->flags))
+		goto done;
+
+	spin_lock(&occ->list_lock);
+
+	if (!test_bit(XFR_IN_PROGRESS, &xfr->flags)) {
+		/* already deleted from list if complete */
+		if (!test_bit(XFR_COMPLETE, &xfr->flags))
+			list_del(&xfr->link);
+	}
+
+	spin_unlock(&occ->list_lock);
+
+	wake_up_all(&client->wait);
+
+done:
+	spin_unlock_irqrestore(&client->lock, flags);
+
+	occ_put_client(client);
+	return 0;
+}
+
+static const struct file_operations occ_fops = {
+	.owner = THIS_MODULE,
+	.open = occ_open,
+	.read = occ_read,
+	.write = occ_write,
+	.release = occ_release,
+};
+
 static int occ_write_sbefifo(struct sbefifo_client *client, const char *buf,
 			     ssize_t len)
 {

@@ -450,6 +699,19 @@ static int occ_probe(struct platform_device *pdev)
 		occ->idx = ida_simple_get(&occ_ida, 1, INT_MAX, GFP_KERNEL);
 	}
 
+	snprintf(occ->name, sizeof(occ->name), "occ%d", occ->idx);
+	occ->mdev.fops = &occ_fops;
+	occ->mdev.minor = MISC_DYNAMIC_MINOR;
+	occ->mdev.name = occ->name;
+	occ->mdev.parent = dev;
+
+	rc = misc_register(&occ->mdev);
+	if (rc) {
+		dev_err(dev, "failed to register miscdevice: %d\n", rc);
+		ida_simple_remove(&occ_ida, occ->idx);
+		return rc;
+	}
+
 	platform_set_drvdata(pdev, occ);
 
 	return 0;

@@ -471,6 +733,8 @@ static int occ_remove(struct platform_device *pdev)
 	}
 	spin_unlock_irqrestore(&occ->list_lock, flags);
 
+	misc_deregister(&occ->mdev);
+
 	cancel_work_sync(&occ->work);
 
 	ida_simple_remove(&occ_ida, occ->idx);

index 1aeb67d..1713550 100644
@@ -19,7 +19,9 @@
 #include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/fsi-occ.h>
 #include <linux/of.h>
+#include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/sched.h>
 #include <linux/slab.h>

@@ -32,8 +34,6 @@
 #define OCC_CMD_DATA_BYTES	4090
 #define OCC_RESP_DATA_BYTES	4089
 
-#define OCC_RESP_CMD_IN_PRG    0xFF
-
 #define OCC_TIMEOUT_MS		1000
 #define OCC_CMD_IN_PRG_WAIT_MS	50
 

@@ -156,23 +156,34 @@ static void occ_put_client(struct occ_client *client)
 	kref_put(&client->kref, occ_client_release);
 }
 
-static int occ_open(struct inode *inode, struct file *file)
+static struct occ_client *occ_open_common(struct occ *occ, unsigned long flags)
 {
-	struct miscdevice *mdev = file->private_data;
-	struct occ *occ = to_occ(mdev);
 	struct occ_client *client = kzalloc(sizeof(*client), GFP_KERNEL);
 
 	if (!client)
-		return -ENOMEM;
+		return NULL;
 
 	client->occ = occ;
 	kref_init(&client->kref);
 	spin_lock_init(&client->lock);
 	init_waitqueue_head(&client->wait);
 
-	if (file->f_flags & O_NONBLOCK)
+	if (flags & O_NONBLOCK)
 		set_bit(CLIENT_NONBLOCKING, &client->flags);
 
+	return client;
+}
+
+static int occ_open(struct inode *inode, struct file *file)
+{
+	struct occ_client *client;
+	struct miscdevice *mdev = file->private_data;
+	struct occ *occ = to_occ(mdev);
+
+	client = occ_open_common(occ, file->f_flags);
+	if (!client)
+		return -ENOMEM;
+
 	file->private_data = client;
 
 	return 0;

@@ -184,15 +195,14 @@ static inline bool occ_read_ready(struct occ_xfr *xfr, struct occ *occ)
 		test_bit(XFR_CANCELED, &xfr->flags) || occ->cancel;
 }
 
-static ssize_t occ_read(struct file *file, char __user *buf, size_t len,
-			loff_t *offset)
+static ssize_t occ_read_common(struct occ_client *client, char __user *ubuf,
+			       char *kbuf, size_t len)
 {
 	int rc;
 	unsigned long flags;
 	size_t bytes;
 	struct occ_xfr *xfr;
 	struct occ *occ;
-	struct occ_client *client = file->private_data;
 
 	if (!client)
 		return -ENODEV;

@@ -247,9 +257,14 @@ static ssize_t occ_read(struct file *file, char __user *buf, size_t len,
 	}
 
 	bytes = min(len, xfr->resp_data_length - client->read_offset);
-	if (copy_to_user(buf, &xfr->buf[client->read_offset], bytes)) {
-		rc = -EFAULT;
-		goto done;
+	if (ubuf) {
+		if (copy_to_user(ubuf, &xfr->buf[client->read_offset],
+				 bytes)) {
+			rc = -EFAULT;
+			goto done;
+		}
+	} else {
+		memcpy(kbuf, &xfr->buf[client->read_offset], bytes);
 	}
 
 	client->read_offset += bytes;

@@ -266,15 +281,23 @@ static ssize_t occ_read(struct file *file, char __user *buf, size_t len,
 	return rc;
 }
 
-static ssize_t occ_write(struct file *file, const char __user *buf,
-			 size_t len, loff_t *offset)
+static ssize_t occ_read(struct file *file, char __user *buf, size_t len,
+			loff_t *offset)
+{
+	struct occ_client *client = file->private_data;
+
+	return occ_read_common(client, buf, NULL, len);
+}
+
+static ssize_t occ_write_common(struct occ_client *client,
+				const char __user *ubuf, const char *kbuf,
+				size_t len)
 {
 	int rc;
 	unsigned long flags;
 	unsigned int i;
 	u16 data_length, checksum = 0;
 	struct occ_xfr *xfr;
-	struct occ_client *client = file->private_data;
 
 	if (!client)
 		return -ENODEV;

@@ -301,9 +324,13 @@ static ssize_t occ_write(struct file *file, const char __user *buf,
 	 * bytes 1-2: data length (msb first)
 	 * bytes 3-n: data
 	 */
-	if (copy_from_user(&xfr->buf[1], buf, len)) {
-		rc = -EFAULT;
-		goto done;
+	if (ubuf) {
+		if (copy_from_user(&xfr->buf[1], ubuf, len)) {
+			rc = -EFAULT;
+			goto done;
+		}
+	} else {
+		memcpy(&xfr->buf[1], kbuf, len);
 	}
 
 	data_length = (xfr->buf[2] << 8) + xfr->buf[3];

@@ -334,12 +361,19 @@ static ssize_t occ_write(struct file *file, const char __user *buf,
 	return rc;
 }
 
-static int occ_release(struct inode *inode, struct file *file)
+static ssize_t occ_write(struct file *file, const char __user *buf,
+			 size_t len, loff_t *offset)
+{
+	struct occ_client *client = file->private_data;
+
+	return occ_write_common(client, buf, NULL, len);
+}
+
+static int occ_release_common(struct occ_client *client)
 {
 	unsigned long flags;
 	struct occ *occ;
 	struct occ_xfr *xfr;
-	struct occ_client *client = file->private_data;
 
 	if (!client)
 		return -ENODEV;

@@ -372,6 +406,13 @@ static int occ_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
+static int occ_release(struct inode *inode, struct file *file)
+{
+	struct occ_client *client = file->private_data;
+
+	return occ_release_common(client);
+}
+
 static const struct file_operations occ_fops = {
 	.owner = THIS_MODULE,
 	.open = occ_open,

@@ -665,12 +706,55 @@ static void occ_worker(struct work_struct *work)
 		goto again;
 }
 
+struct occ_client *occ_drv_open(struct device *dev, unsigned long flags)
+{
+	struct occ *occ = dev_get_drvdata(dev);
+
+	if (!occ)
+		return NULL;
+
+	return occ_open_common(occ, flags);
+}
+EXPORT_SYMBOL_GPL(occ_drv_open);
+
+int occ_drv_read(struct occ_client *client, char *buf, size_t len)
+{
+	return occ_read_common(client, NULL, buf, len);
+}
+EXPORT_SYMBOL_GPL(occ_drv_read);
+
+int occ_drv_write(struct occ_client *client, const char *buf, size_t len)
+{
+	return occ_write_common(client, NULL, buf, len);
+}
+EXPORT_SYMBOL_GPL(occ_drv_write);
+
+void occ_drv_release(struct occ_client *client)
+{
+	occ_release_common(client);
+}
+EXPORT_SYMBOL_GPL(occ_drv_release);
+
+static int occ_unregister_child(struct device *dev, void *data)
+{
+	struct platform_device *child = to_platform_device(dev);
+
+	of_device_unregister(child);
+	if (dev->of_node)
+		of_node_clear_flag(dev->of_node, OF_POPULATED);
+
+	return 0;
+}
+
 static int occ_probe(struct platform_device *pdev)
 {
-	int rc;
+	int rc, child_idx = 0;
 	u32 reg;
 	struct occ *occ;
+	struct device_node *np;
+	struct platform_device *child;
 	struct device *dev = &pdev->dev;
+	char child_name[32];
 
 	occ = devm_kzalloc(dev, sizeof(*occ), GFP_KERNEL);
 	if (!occ)

@@ -712,6 +796,15 @@ static int occ_probe(struct platform_device *pdev)
 		return rc;
 	}
 
+	/* create platform devs for dts child nodes (hwmon, etc) */
+	for_each_available_child_of_node(dev->of_node, np) {
+		snprintf(child_name, sizeof(child_name), "occ%d-dev%d",
+			 occ->idx, child_idx++);
+		child = of_platform_device_create(np, child_name, dev);
+		if (!child)
+			dev_warn(dev, "failed to create child node dev\n");
+	}
+
 	platform_set_drvdata(pdev, occ);
 
 	return 0;

@@ -734,6 +827,7 @@ static int occ_remove(struct platform_device *pdev)
 	spin_unlock_irqrestore(&occ->list_lock, flags);
 
 	misc_deregister(&occ->mdev);
+	device_for_each_child(&pdev->dev, NULL, occ_unregister_child);
 
 	cancel_work_sync(&occ->work);
 

41 lines not on this page · raw message