[media] winbond-cir: add carrier detection

The winbond hardware has a counter for leading edges, which increases as
they are received. As we read raw IR from a fifo in an interrupt handler,
we cannot correlate them to specific IR pulses so we simply count all
pulses and edges until we go idle and disable the receiver.

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 75 insertions, 5 deletions

diff --git a/drivers/media/rc/winbond-cir.c b/drivers/media/rc/winbond-cir.c
index f040bbfd2100..7f3c476dde05 100644
--- a/drivers/media/rc/winbond-cir.c
+++ b/drivers/media/rc/winbond-cir.c
@@ -7,6 +7,7 @@
  *  with minor modifications.
  *
  *  Original Author: David Härdeman <david@hardeman.nu>
+ *     Copyright (C) 2012 Sean Young <sean@mess.org>
  *     Copyright (C) 2009 - 2011 David Härdeman <david@hardeman.nu>
  *
  *  Dedicated to my daughter Matilda, without whose loving attention this
@@ -22,9 +23,7 @@
  *    o IR Receive
  *    o IR Transmit
  *    o Wake-On-CIR functionality
- *
- *  To do:
- *    o Learning
+ *    o Carrier detection
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -149,6 +148,12 @@
 #define WBCIR_REGSEL_MASK       0x20
 /* Starting address of selected register in WBCIR_REG_WCEIR_INDEX */
 #define WBCIR_REG_ADDR0         0x00
+/* Enable carrier counter */
+#define WBCIR_CNTR_EN           0x01
+/* Reset carrier counter */
+#define WBCIR_CNTR_R            0x02
+/* Invert TX */
+#define WBCIR_IRTX_INV          0x04
 
 /* Valid banks for the SP3 UART */
 enum wbcir_bank {
@@ -207,6 +212,8 @@ struct wbcir_data {
         /* RX state */
         enum wbcir_rxstate rxstate;
         struct led_trigger *rxtrigger;
+        int carrier_report_enabled;
+        u32 pulse_duration;
 
         /* TX state */
         enum wbcir_txstate txstate;
@@ -329,6 +336,30 @@ wbcir_to_rc6cells(u8 val)
  *****************************************************************************/
 
 static void
+wbcir_carrier_report(struct wbcir_data *data)
+{
+        unsigned counter = inb(data->ebase + WBCIR_REG_ECEIR_CNT_LO) |
+                        inb(data->ebase + WBCIR_REG_ECEIR_CNT_HI) << 8;
+
+        if (counter > 0 && counter < 0xffff) {
+                DEFINE_IR_RAW_EVENT(ev);
+
+                ev.carrier_report = 1;
+                ev.carrier = DIV_ROUND_CLOSEST(counter * 1000000u,
+                                                data->pulse_duration);
+
+                ir_raw_event_store(data->dev, &ev);
+        }
+
+        /* reset and restart the counter */
+        data->pulse_duration = 0;
+        wbcir_set_bits(data->ebase + WBCIR_REG_ECEIR_CCTL, WBCIR_CNTR_R,
+                                                WBCIR_CNTR_EN | WBCIR_CNTR_R);
+        wbcir_set_bits(data->ebase + WBCIR_REG_ECEIR_CCTL, WBCIR_CNTR_EN,
+                                                WBCIR_CNTR_EN | WBCIR_CNTR_R);
+}
+
+static void
 wbcir_idle_rx(struct rc_dev *dev, bool idle)
 {
         struct wbcir_data *data = dev->priv;
@@ -341,6 +372,10 @@ wbcir_idle_rx(struct rc_dev *dev, bool idle)
         if (idle && data->rxstate != WBCIR_RXSTATE_INACTIVE) {
                 data->rxstate = WBCIR_RXSTATE_INACTIVE;
                 led_trigger_event(data->rxtrigger, LED_OFF);
+
+                if (data->carrier_report_enabled)
+                        wbcir_carrier_report(data);
+
                 /* Tell hardware to go idle by setting RXINACTIVE */
                 outb(WBCIR_RX_DISABLE, data->sbase + WBCIR_REG_SP3_ASCR);
         }
@@ -351,14 +386,21 @@ wbcir_irq_rx(struct wbcir_data *data, struct pnp_dev *device)
 {
         u8 irdata;
         DEFINE_IR_RAW_EVENT(rawir);
+        unsigned duration;
 
         /* Since RXHDLEV is set, at least 8 bytes are in the FIFO */
         while (inb(data->sbase + WBCIR_REG_SP3_LSR) & WBCIR_RX_AVAIL) {
                 irdata = inb(data->sbase + WBCIR_REG_SP3_RXDATA);
                 if (data->rxstate == WBCIR_RXSTATE_ERROR)
                         continue;
+
+                duration = ((irdata & 0x7F) + 1) * 2;
                 rawir.pulse = irdata & 0x80 ? false : true;
-                rawir.duration = US_TO_NS(((irdata & 0x7F) + 1) * 2);
+                rawir.duration = US_TO_NS(duration);
+
+                if (rawir.pulse)
+                        data->pulse_duration += duration;
+
                 ir_raw_event_store_with_filter(data->dev, &rawir);
         }
 
@@ -488,6 +530,33 @@ wbcir_irq_handler(int irqno, void *cookie)
  *****************************************************************************/
 
 static int
+wbcir_set_carrier_report(struct rc_dev *dev, int enable)
+{
+        struct wbcir_data *data = dev->priv;
+        unsigned long flags;
+
+        spin_lock_irqsave(&data->spinlock, flags);
+
+        if (data->carrier_report_enabled == enable) {
+                spin_unlock_irqrestore(&data->spinlock, flags);
+                return 0;
+        }
+
+        data->pulse_duration = 0;
+        wbcir_set_bits(data->ebase + WBCIR_REG_ECEIR_CCTL, WBCIR_CNTR_R,
+                                                WBCIR_CNTR_EN | WBCIR_CNTR_R);
+
+        if (enable && data->dev->idle)
+                wbcir_set_bits(data->ebase + WBCIR_REG_ECEIR_CCTL,
+                                WBCIR_CNTR_EN, WBCIR_CNTR_EN | WBCIR_CNTR_R);
+
+        data->carrier_report_enabled = enable;
+        spin_unlock_irqrestore(&data->spinlock, flags);
+
+        return 0;
+}
+
+static int
 wbcir_txcarrier(struct rc_dev *dev, u32 carrier)
 {
         struct wbcir_data *data = dev->priv;
@@ -833,7 +902,7 @@ wbcir_init_hw(struct wbcir_data *data)
 
         /* Set IRTX_INV */
         if (invert)
-                outb(0x04, data->ebase + WBCIR_REG_ECEIR_CCTL);
+                outb(WBCIR_IRTX_INV, data->ebase + WBCIR_REG_ECEIR_CCTL);
         else
                 outb(0x00, data->ebase + WBCIR_REG_ECEIR_CCTL);
 
@@ -1014,6 +1083,7 @@ wbcir_probe(struct pnp_dev *device, const struct pnp_device_id *dev_id)
         data->dev->input_id.version = WBCIR_ID_CHIP;
         data->dev->map_name = RC_MAP_RC6_MCE;
         data->dev->s_idle = wbcir_idle_rx;
+        data->dev->s_carrier_report = wbcir_set_carrier_report;
         data->dev->s_tx_mask = wbcir_txmask;
         data->dev->s_tx_carrier = wbcir_txcarrier;
         data->dev->tx_ir = wbcir_tx;