[PATCH v2 3/5] rc: img-ir: biphase enabled with workaround
From: Sifan Naeem
Date: Thu Dec 11 2014 - 15:06:38 EST
Biphase decoding in the current img-ir has got a quirk, where multiple
Interrupts are generated when an incomplete IR code is received by the
decoder.
Patch adds a work around for the quirk and enables biphase decoding.
Changes from v1:
* rebased due to conflict with "img-ir/hw: Fix potential deadlock stopping timer"
* spinlock taken in img_ir_suspend_timer
* check for hw->stopping before handling quirks in img_ir_isr_hw
* new memeber added to img_ir_priv_hw to save irq status over suspend
Signed-off-by: Sifan Naeem <sifan.naeem@xxxxxxxxxx>
---
drivers/media/rc/img-ir/img-ir-hw.c | 60 +++++++++++++++++++++++++++++++++--
drivers/media/rc/img-ir/img-ir-hw.h | 4 +++
2 files changed, 61 insertions(+), 3 deletions(-)
diff --git a/drivers/media/rc/img-ir/img-ir-hw.c b/drivers/media/rc/img-ir/img-ir-hw.c
index 9cecda7..5c32f05 100644
--- a/drivers/media/rc/img-ir/img-ir-hw.c
+++ b/drivers/media/rc/img-ir/img-ir-hw.c
@@ -52,6 +52,11 @@ static struct img_ir_decoder *img_ir_decoders[] = {
#define IMG_IR_QUIRK_CODE_BROKEN 0x1 /* Decode is broken */
#define IMG_IR_QUIRK_CODE_LEN_INCR 0x2 /* Bit length needs increment */
+/*
+ * The decoder generates rapid interrupts without actually having
+ * received any new data after an incomplete IR code is decoded.
+ */
+#define IMG_IR_QUIRK_CODE_IRQ 0x4
/* functions for preprocessing timings, ensuring max is set */
@@ -542,6 +547,7 @@ static void img_ir_set_decoder(struct img_ir_priv *priv,
*/
spin_unlock_irq(&priv->lock);
del_timer_sync(&hw->end_timer);
+ del_timer_sync(&hw->suspend_timer);
spin_lock_irq(&priv->lock);
hw->stopping = false;
@@ -861,6 +867,29 @@ static void img_ir_end_timer(unsigned long arg)
spin_unlock_irq(&priv->lock);
}
+/*
+ * Timer function to re-enable the current protocol after it had been
+ * cleared when invalid interrupts were generated due to a quirk in the
+ * img-ir decoder.
+ */
+static void img_ir_suspend_timer(unsigned long arg)
+{
+ struct img_ir_priv *priv = (struct img_ir_priv *)arg;
+
+ spin_lock_irq(&priv->lock);
+ /*
+ * Don't overwrite enabled valid/match IRQs if they have already been
+ * changed by e.g. a filter change.
+ */
+ if ((priv->hw.quirk_suspend_irq & IMG_IR_IRQ_EDGE) ==
+ img_ir_read(priv, IMG_IR_IRQ_ENABLE))
+ img_ir_write(priv, IMG_IR_IRQ_ENABLE,
+ priv->hw.quirk_suspend_irq);
+ /* enable */
+ img_ir_write(priv, IMG_IR_CONTROL, priv->hw.reg_timings.ctrl);
+ spin_unlock_irq(&priv->lock);
+}
+
#ifdef CONFIG_COMMON_CLK
static void img_ir_change_frequency(struct img_ir_priv *priv,
struct clk_notifier_data *change)
@@ -926,15 +955,38 @@ void img_ir_isr_hw(struct img_ir_priv *priv, u32 irq_status)
if (!hw->decoder)
return;
+ ct = hw->decoder->control.code_type;
+
ir_status = img_ir_read(priv, IMG_IR_STATUS);
- if (!(ir_status & (IMG_IR_RXDVAL | IMG_IR_RXDVALD2)))
+ if (!(ir_status & (IMG_IR_RXDVAL | IMG_IR_RXDVALD2))) {
+ if (!(priv->hw.ct_quirks[ct] & IMG_IR_QUIRK_CODE_IRQ) ||
+ hw->stopping)
+ return;
+ /*
+ * The below functionality is added as a work around to stop
+ * multiple Interrupts generated when an incomplete IR code is
+ * received by the decoder.
+ * The decoder generates rapid interrupts without actually
+ * having received any new data. After a single interrupt it's
+ * expected to clear up, but instead multiple interrupts are
+ * rapidly generated. only way to get out of this loop is to
+ * reset the control register after a short delay.
+ */
+ img_ir_write(priv, IMG_IR_CONTROL, 0);
+ hw->quirk_suspend_irq = img_ir_read(priv, IMG_IR_IRQ_ENABLE);
+ img_ir_write(priv, IMG_IR_IRQ_ENABLE,
+ hw->quirk_suspend_irq & IMG_IR_IRQ_EDGE);
+
+ /* Timer activated to re-enable the protocol. */
+ mod_timer(&hw->suspend_timer,
+ jiffies + msecs_to_jiffies(5));
return;
+ }
ir_status &= ~(IMG_IR_RXDVAL | IMG_IR_RXDVALD2);
img_ir_write(priv, IMG_IR_STATUS, ir_status);
len = (ir_status & IMG_IR_RXDLEN) >> IMG_IR_RXDLEN_SHIFT;
/* some versions report wrong length for certain code types */
- ct = hw->decoder->control.code_type;
if (hw->ct_quirks[ct] & IMG_IR_QUIRK_CODE_LEN_INCR)
++len;
@@ -976,7 +1028,7 @@ static void img_ir_probe_hw_caps(struct img_ir_priv *priv)
hw->ct_quirks[IMG_IR_CODETYPE_PULSELEN]
|= IMG_IR_QUIRK_CODE_LEN_INCR;
hw->ct_quirks[IMG_IR_CODETYPE_BIPHASE]
- |= IMG_IR_QUIRK_CODE_BROKEN;
+ |= IMG_IR_QUIRK_CODE_IRQ;
hw->ct_quirks[IMG_IR_CODETYPE_2BITPULSEPOS]
|= IMG_IR_QUIRK_CODE_BROKEN;
}
@@ -995,6 +1047,8 @@ int img_ir_probe_hw(struct img_ir_priv *priv)
/* Set up the end timer */
setup_timer(&hw->end_timer, img_ir_end_timer, (unsigned long)priv);
+ setup_timer(&hw->suspend_timer, img_ir_suspend_timer,
+ (unsigned long)priv);
/* Register a clock notifier */
if (!IS_ERR(priv->clk)) {
diff --git a/drivers/media/rc/img-ir/img-ir-hw.h b/drivers/media/rc/img-ir/img-ir-hw.h
index beac3a6..b31ffc9 100644
--- a/drivers/media/rc/img-ir/img-ir-hw.h
+++ b/drivers/media/rc/img-ir/img-ir-hw.h
@@ -218,6 +218,7 @@ enum img_ir_mode {
* @rdev: Remote control device
* @clk_nb: Notifier block for clock notify events.
* @end_timer: Timer until repeat timeout.
+ * @suspend_timer: Timer to re-enable protocol.
* @decoder: Current decoder settings.
* @enabled_protocols: Currently enabled protocols.
* @clk_hz: Current core clock rate in Hz.
@@ -228,12 +229,14 @@ enum img_ir_mode {
* @stopping: Indicates that decoder is being taken down and timers
* should not be restarted.
* @suspend_irqen: Saved IRQ enable mask over suspend.
+ * @quirk_suspend_irq: Saved IRQ enable mask over quirk suspend timer.
*/
struct img_ir_priv_hw {
unsigned int ct_quirks[4];
struct rc_dev *rdev;
struct notifier_block clk_nb;
struct timer_list end_timer;
+ struct timer_list suspend_timer;
const struct img_ir_decoder *decoder;
u64 enabled_protocols;
unsigned long clk_hz;
@@ -244,6 +247,7 @@ struct img_ir_priv_hw {
enum img_ir_mode mode;
bool stopping;
u32 suspend_irqen;
+ u32 quirk_suspend_irq;
};
static inline bool img_ir_hw_enabled(struct img_ir_priv_hw *hw)
--
1.7.9.5
--
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