media: rc: meson-ir: add timeout on idle

Commit Message

Matthias Reichl March 6, 2018, 5:41 p.m. UTC

Meson doesn't seem to be able to generate timeout events
in hardware. So install a software timer to generate the
timeout events required by the decoders to prevent
"ghost keypresses".

Signed-off-by: Matthias Reichl <[e-mail]>
---
 drivers/media/rc/meson-ir.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

Patch

diff --git a/drivers/media/rc/meson-ir.c b/drivers/media/rc/meson-ir.c
index f2204eb77e2a..f34c5836412b 100644
--- a/drivers/media/rc/meson-ir.c
+++ b/drivers/media/rc/meson-ir.c
@@ -69,6 +69,7 @@  struct meson_ir {
 	void __iomem	*reg;
 	struct rc_dev	*rc;
 	spinlock_t	lock;
+	struct timer_list timeout_timer;
 };
 
 static void meson_ir_set_mask(struct meson_ir *ir, unsigned int reg,
@@ -98,6 +99,10 @@  static irqreturn_t meson_ir_irq(int irqno, void *dev_id)
 	rawir.pulse = !!(status & STATUS_IR_DEC_IN);
 
 	ir_raw_event_store(ir->rc, &rawir);
+
+	mod_timer(&ir->timeout_timer,
+		jiffies + nsecs_to_jiffies(ir->rc->timeout));
+
 	ir_raw_event_handle(ir->rc);
 
 	spin_unlock(&ir->lock);
@@ -105,6 +110,17 @@  static irqreturn_t meson_ir_irq(int irqno, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static void meson_ir_timeout_timer(struct timer_list *t)
+{
+	struct meson_ir *ir = from_timer(ir, t, timeout_timer);
+	DEFINE_IR_RAW_EVENT(rawir);
+
+	rawir.timeout = true;
+	rawir.duration = ir->rc->timeout;
+	ir_raw_event_store(ir->rc, &rawir);
+	ir_raw_event_handle(ir->rc);
+}
+
 static int meson_ir_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -145,7 +161,9 @@  static int meson_ir_probe(struct platform_device *pdev)
 	ir->rc->map_name = map_name ? map_name : RC_MAP_EMPTY;
 	ir->rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
 	ir->rc->rx_resolution = US_TO_NS(MESON_TRATE);
+	ir->rc->min_timeout = 1;
 	ir->rc->timeout = MS_TO_NS(200);
+	ir->rc->max_timeout = 10 * IR_DEFAULT_TIMEOUT;
 	ir->rc->driver_name = DRIVER_NAME;
 
 	spin_lock_init(&ir->lock);
@@ -157,6 +175,8 @@  static int meson_ir_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	timer_setup(&ir->timeout_timer, meson_ir_timeout_timer, 0);
+
 	ret = devm_request_irq(dev, irq, meson_ir_irq, 0, NULL, ir);
 	if (ret) {
 		dev_err(dev, "failed to request irq\n");
@@ -198,6 +218,8 @@  static int meson_ir_remove(struct platform_device *pdev)
 	meson_ir_set_mask(ir, IR_DEC_REG1, REG1_ENABLE, 0);
 	spin_unlock_irqrestore(&ir->lock, flags);
 
+	del_timer_sync(&ir->timeout_timer);
+
 	return 0;
 }