V4L/DVB: ir-nec-decoder: Add sysfs node to enable/disable per irrcv

With the help of raw_register/raw_unregister, adds a sysfs group
associated with the decoder, inside the corresponding irrcv node.

Writing 1 to nec_decoder/enabled enables the decoder, while
writing 0 disables it.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

2 files changed, 133 insertions, 2 deletions

diff --git a/drivers/media/IR/ir-nec-decoder.c b/drivers/media/IR/ir-nec-decoder.c
index cb57cc287734..83a9912722f4 100644
--- a/drivers/media/IR/ir-nec-decoder.c
+++ b/drivers/media/IR/ir-nec-decoder.c
@@ -39,6 +39,85 @@
 
 #define REPEAT_TIME     240 /* ms */
 
+/* Used to register nec_decoder clients */
+static LIST_HEAD(decoder_list);
+static spinlock_t decoder_lock;
+
+struct decoder_data {
+        struct list_head        list;
+        struct ir_input_dev     *ir_dev;
+        int                     enabled:1;
+};
+
+
+/**
+ * get_decoder_data()   - gets decoder data
+ * @input_dev:  input device
+ *
+ * Returns the struct decoder_data that corresponds to a device
+ */
+
+static struct decoder_data *get_decoder_data(struct  ir_input_dev *ir_dev)
+{
+        struct decoder_data *data = NULL;
+
+        spin_lock(&decoder_lock);
+        list_for_each_entry(data, &decoder_list, list) {
+                if (data->ir_dev == ir_dev)
+                        break;
+        }
+        spin_unlock(&decoder_lock);
+        return data;
+}
+
+static ssize_t store_enabled(struct device *d,
+                             struct device_attribute *mattr,
+                             const char *buf,
+                             size_t len)
+{
+        unsigned long value;
+        struct ir_input_dev *ir_dev = dev_get_drvdata(d);
+        struct decoder_data *data = get_decoder_data(ir_dev);
+
+        if (!data)
+                return -EINVAL;
+
+        if (strict_strtoul(buf, 10, &value) || value > 1)
+                return -EINVAL;
+
+        data->enabled = value;
+
+        return len;
+}
+
+static ssize_t show_enabled(struct device *d,
+                             struct device_attribute *mattr, char *buf)
+{
+        struct ir_input_dev *ir_dev = dev_get_drvdata(d);
+        struct decoder_data *data = get_decoder_data(ir_dev);
+
+        if (!data)
+                return -EINVAL;
+
+        if (data->enabled)
+                return sprintf(buf, "1\n");
+        else
+        return sprintf(buf, "0\n");
+}
+
+static DEVICE_ATTR(enabled, S_IRUGO | S_IWUSR, show_enabled, store_enabled);
+
+static struct attribute *decoder_attributes[] = {
+        &dev_attr_enabled.attr,
+        NULL
+};
+
+static struct attribute_group decoder_attribute_group = {
+        .name   = "nec_decoder",
+        .attrs  = decoder_attributes,
+};
+
+
 /** is_repeat - Check if it is a NEC repeat event
  * @input_dev:  the struct input_dev descriptor of the device
  * @pos:        the position of the first event
@@ -184,9 +263,15 @@ static int ir_nec_decode(struct input_dev *input_dev,
                          struct ir_raw_event *evs,
                          int len)
 {
+        struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
+        struct decoder_data *data;
         int pos = 0;
         int rc = 0;
 
+        data = get_decoder_data(ir_dev);
+        if (!data || !data->enabled)
+                return 0;
+
         while (pos < len) {
                 if (__ir_nec_decode(input_dev, evs, len, &pos) > 0)
                         rc++;
@@ -194,8 +279,54 @@ static int ir_nec_decode(struct input_dev *input_dev,
         return rc;
 }
 
+static int ir_nec_register(struct input_dev *input_dev)
+{
+        struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
+        struct decoder_data *data;
+        int rc;
+
+        rc = sysfs_create_group(&ir_dev->dev.kobj, &decoder_attribute_group);
+        if (rc < 0)
+                return rc;
+
+        data = kzalloc(sizeof(*data), GFP_KERNEL);
+        if (!data) {
+                sysfs_remove_group(&ir_dev->dev.kobj, &decoder_attribute_group);
+                return -ENOMEM;
+        }
+
+        data->ir_dev = ir_dev;
+        data->enabled = 1;
+
+        spin_lock(&decoder_lock);
+        list_add_tail(&data->list, &decoder_list);
+        spin_unlock(&decoder_lock);
+
+        return 0;
+}
+
+static int ir_nec_unregister(struct input_dev *input_dev)
+{
+        struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
+        static struct decoder_data *data;
+
+        data = get_decoder_data(ir_dev);
+        if (!data)
+                return 0;
+
+        sysfs_remove_group(&ir_dev->dev.kobj, &decoder_attribute_group);
+
+        spin_lock(&decoder_lock);
+        list_del(&data->list);
+        spin_unlock(&decoder_lock);
+
+        return 0;
+}
+
 static struct ir_raw_handler nec_handler = {
-        .decode = ir_nec_decode,
+        .decode         = ir_nec_decode,
+        .raw_register   = ir_nec_register,
+        .raw_unregister = ir_nec_unregister,
 };
 
 static int __init ir_nec_decode_init(void)
diff --git a/drivers/media/IR/ir-raw-event.c b/drivers/media/IR/ir-raw-event.c
index 11f23f4491b2..371d88e5a586 100644
--- a/drivers/media/IR/ir-raw-event.c
+++ b/drivers/media/IR/ir-raw-event.c
@@ -223,7 +223,7 @@ static void init_decoders(struct work_struct *work)
 void ir_raw_init(void)
 {
         spin_lock_init(&ir_raw_handler_lock);
-        
+
 #ifdef MODULE
         INIT_WORK(&wq_load, init_decoders);
         schedule_work(&wq_load);