linux-kernel - [PATCH RFC] media: lirc: Allow lirc dev to talk to rc device

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Date:	Fri, 12 Jul 2013 09:55:28 +0100
From:	Srinivas KANDAGATLA <srinivas.kandagatla@...com>
To:	linux-media@...r.kernel.org
Cc:	alipowski@...eria.pl, Mauro Carvalho Chehab <mchehab@...hat.com>,
	linux-kernel@...r.kernel.org, srinivas.kandagatla@...il.com,
	srinivas.kandagatla@...com
Subject: [PATCH RFC] media: lirc: Allow lirc dev to talk to rc device

From: Srinivas Kandagatla <srinivas.kandagatla@...com>

The use case is simple, if any rc device has allowed protocols =
RC_TYPE_LIRC and map_name = RC_MAP_LIRC set, the driver open will be never
called. The reason for this is, all of the key maps except lirc have some
KEYS in there map, so during rc_register_device process these keys are
matched against the input drivers and open is performed, so for the case
of RC_MAP_EMPTY, a tty/vt/keyboard is matched and the driver open is
performed.

In case of lirc, there is no match and result is that there is no open
performed, however the lirc-dev will go ahead and create a /dev/lirc0
node. Now when lircd/mode2 opens this device, no data is available
because the driver was never opened.

lirc_dev seems to have no link with actual rc device w.r.t open/close.
This patch adds the missing link rc_dev pointer to lirc_driver structure
for cases like this, so that it can do the open/close of the real driver
in accordance to lircd/mode2 open/close.

Without this patch its impossible to open a rc device which has
RC_TYPE_LIRC ad RC_MAP_LIRC set.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@...com>
---
 drivers/media/rc/ir-lirc-codec.c |    1 +
 drivers/media/rc/lirc_dev.c      |   14 ++++++++++++++
 include/media/lirc_dev.h         |    1 +
 3 files changed, 16 insertions(+), 0 deletions(-)

diff --git a/drivers/media/rc/ir-lirc-codec.c b/drivers/media/rc/ir-lirc-codec.c
index e456126..d5ad27f 100644
--- a/drivers/media/rc/ir-lirc-codec.c
+++ b/drivers/media/rc/ir-lirc-codec.c
@@ -375,6 +375,7 @@ static int ir_lirc_register(struct rc_dev *dev)
 	drv->code_length = sizeof(struct ir_raw_event) * 8;
 	drv->fops = &lirc_fops;
 	drv->dev = &dev->dev;
+	drv->rc_dev = dev;
 	drv->owner = THIS_MODULE;
 
 	drv->minor = lirc_register_driver(drv);
diff --git a/drivers/media/rc/lirc_dev.c b/drivers/media/rc/lirc_dev.c
index 8dc057b..485bf7d 100644
--- a/drivers/media/rc/lirc_dev.c
+++ b/drivers/media/rc/lirc_dev.c
@@ -35,6 +35,7 @@
 #include <linux/device.h>
 #include <linux/cdev.h>
 
+#include <media/rc-core.h>
 #include <media/lirc.h>
 #include <media/lirc_dev.h>
 
@@ -437,6 +438,7 @@ EXPORT_SYMBOL(lirc_unregister_driver);
 int lirc_dev_fop_open(struct inode *inode, struct file *file)
 {
 	struct irctl *ir;
+	struct rc_dev *rc_dev;
 	struct cdev *cdev;
 	int retval = 0;
 
@@ -467,6 +469,13 @@ int lirc_dev_fop_open(struct inode *inode, struct file *file)
 		goto error;
 	}
 
+	rc_dev = ir->d.rc_dev;
+	if (rc_dev && rc_dev->open) {
+		retval = rc_dev->open(rc_dev);
+		if (retval)
+			goto error;
+	}
+
 	cdev = ir->cdev;
 	if (try_module_get(cdev->owner)) {
 		ir->open++;
@@ -499,6 +508,7 @@ int lirc_dev_fop_close(struct inode *inode, struct file *file)
 {
 	struct irctl *ir = irctls[iminor(inode)];
 	struct cdev *cdev;
+	struct rc_dev *rc_dev;
 
 	if (!ir) {
 		printk(KERN_ERR "%s: called with invalid irctl\n", __func__);
@@ -511,6 +521,10 @@ int lirc_dev_fop_close(struct inode *inode, struct file *file)
 
 	WARN_ON(mutex_lock_killable(&lirc_dev_lock));
 
+	rc_dev = ir->d.rc_dev;
+	if (rc_dev && rc_dev->close)
+		rc_dev->close(rc_dev);
+
 	ir->open--;
 	if (ir->attached) {
 		ir->d.set_use_dec(ir->d.data);
diff --git a/include/media/lirc_dev.h b/include/media/lirc_dev.h
index 168dd0b..96dccb6 100644
--- a/include/media/lirc_dev.h
+++ b/include/media/lirc_dev.h
@@ -139,6 +139,7 @@ struct lirc_driver {
 	struct lirc_buffer *rbuf;
 	int (*set_use_inc) (void *data);
 	void (*set_use_dec) (void *data);
+	struct rc_dev *rc_dev;
 	const struct file_operations *fops;
 	struct device *dev;
 	struct module *owner;
-- 
1.7.6.5

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