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Diffstat (limited to 'drivers/media/rc/img-ir/img-ir-raw.c')
-rw-r--r--drivers/media/rc/img-ir/img-ir-raw.c151
1 files changed, 151 insertions, 0 deletions
diff --git a/drivers/media/rc/img-ir/img-ir-raw.c b/drivers/media/rc/img-ir/img-ir-raw.c
new file mode 100644
index 000000000..8b0bdd960
--- /dev/null
+++ b/drivers/media/rc/img-ir/img-ir-raw.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * ImgTec IR Raw Decoder found in PowerDown Controller.
+ *
+ * Copyright 2010-2014 Imagination Technologies Ltd.
+ *
+ * This ties into the input subsystem using the RC-core in raw mode. Raw IR
+ * signal edges are reported and decoded by generic software decoders.
+ */
+
+#include <linux/spinlock.h>
+#include <media/rc-core.h>
+#include "img-ir.h"
+
+#define ECHO_TIMEOUT_MS 150 /* ms between echos */
+
+/* must be called with priv->lock held */
+static void img_ir_refresh_raw(struct img_ir_priv *priv, u32 irq_status)
+{
+ struct img_ir_priv_raw *raw = &priv->raw;
+ struct rc_dev *rc_dev = priv->raw.rdev;
+ int multiple;
+ u32 ir_status;
+
+ /* find whether both rise and fall was detected */
+ multiple = ((irq_status & IMG_IR_IRQ_EDGE) == IMG_IR_IRQ_EDGE);
+ /*
+ * If so, we need to see if the level has actually changed.
+ * If it's just noise that we didn't have time to process,
+ * there's no point reporting it.
+ */
+ ir_status = img_ir_read(priv, IMG_IR_STATUS) & IMG_IR_IRRXD;
+ if (multiple && ir_status == raw->last_status)
+ return;
+ raw->last_status = ir_status;
+
+ /* report the edge to the IR raw decoders */
+ if (ir_status) /* low */
+ ir_raw_event_store_edge(rc_dev, false);
+ else /* high */
+ ir_raw_event_store_edge(rc_dev, true);
+ ir_raw_event_handle(rc_dev);
+}
+
+/* called with priv->lock held */
+void img_ir_isr_raw(struct img_ir_priv *priv, u32 irq_status)
+{
+ struct img_ir_priv_raw *raw = &priv->raw;
+
+ /* check not removing */
+ if (!raw->rdev)
+ return;
+
+ img_ir_refresh_raw(priv, irq_status);
+
+ /* start / push back the echo timer */
+ mod_timer(&raw->timer, jiffies + msecs_to_jiffies(ECHO_TIMEOUT_MS));
+}
+
+/*
+ * Echo timer callback function.
+ * The raw decoders expect to get a final sample even if there are no edges, in
+ * order to be assured of the final space. If there are no edges for a certain
+ * time we use this timer to emit a final sample to satisfy them.
+ */
+static void img_ir_echo_timer(struct timer_list *t)
+{
+ struct img_ir_priv *priv = from_timer(priv, t, raw.timer);
+
+ spin_lock_irq(&priv->lock);
+
+ /* check not removing */
+ if (priv->raw.rdev)
+ /*
+ * It's safe to pass irq_status=0 since it's only used to check
+ * for double edges.
+ */
+ img_ir_refresh_raw(priv, 0);
+
+ spin_unlock_irq(&priv->lock);
+}
+
+void img_ir_setup_raw(struct img_ir_priv *priv)
+{
+ u32 irq_en;
+
+ if (!priv->raw.rdev)
+ return;
+
+ /* clear and enable edge interrupts */
+ spin_lock_irq(&priv->lock);
+ irq_en = img_ir_read(priv, IMG_IR_IRQ_ENABLE);
+ irq_en |= IMG_IR_IRQ_EDGE;
+ img_ir_write(priv, IMG_IR_IRQ_CLEAR, IMG_IR_IRQ_EDGE);
+ img_ir_write(priv, IMG_IR_IRQ_ENABLE, irq_en);
+ spin_unlock_irq(&priv->lock);
+}
+
+int img_ir_probe_raw(struct img_ir_priv *priv)
+{
+ struct img_ir_priv_raw *raw = &priv->raw;
+ struct rc_dev *rdev;
+ int error;
+
+ /* Set up the echo timer */
+ timer_setup(&raw->timer, img_ir_echo_timer, 0);
+
+ /* Allocate raw decoder */
+ raw->rdev = rdev = rc_allocate_device(RC_DRIVER_IR_RAW);
+ if (!rdev) {
+ dev_err(priv->dev, "cannot allocate raw input device\n");
+ return -ENOMEM;
+ }
+ rdev->priv = priv;
+ rdev->map_name = RC_MAP_EMPTY;
+ rdev->device_name = "IMG Infrared Decoder Raw";
+
+ /* Register raw decoder */
+ error = rc_register_device(rdev);
+ if (error) {
+ dev_err(priv->dev, "failed to register raw IR input device\n");
+ rc_free_device(rdev);
+ raw->rdev = NULL;
+ return error;
+ }
+
+ return 0;
+}
+
+void img_ir_remove_raw(struct img_ir_priv *priv)
+{
+ struct img_ir_priv_raw *raw = &priv->raw;
+ struct rc_dev *rdev = raw->rdev;
+ u32 irq_en;
+
+ if (!rdev)
+ return;
+
+ /* switch off and disable raw (edge) interrupts */
+ spin_lock_irq(&priv->lock);
+ raw->rdev = NULL;
+ irq_en = img_ir_read(priv, IMG_IR_IRQ_ENABLE);
+ irq_en &= ~IMG_IR_IRQ_EDGE;
+ img_ir_write(priv, IMG_IR_IRQ_ENABLE, irq_en);
+ img_ir_write(priv, IMG_IR_IRQ_CLEAR, IMG_IR_IRQ_EDGE);
+ spin_unlock_irq(&priv->lock);
+
+ rc_unregister_device(rdev);
+
+ del_timer_sync(&raw->timer);
+}