V4L/DVB: v4l2_subdev, cx23885: Differentiate IR carrier sense and I/O pin inversion

There is a distinction on IR Tx for the CX2388[578] chips of carrier
sense inversion (space is a carrier burst and mark is no burst) and I/O
pin level inversion (0 is high output level, 1 is low output level).
Allow the caller to set these parameters distinctly as v4l2_subdevice
IR parameters.  This permits the IR device to be configured and enabled
without the IR Tx LED being on during idle/space time due to an external
hardware level inversion

Signed-off-by: Andy Walls <awalls@md.metrocast.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

2 files changed, 25 insertions, 9 deletions

diff --git a/drivers/media/video/cx23885/cx23885-input.c b/drivers/media/video/cx23885/cx23885-input.c
index d0b1613ede2f..496d751ffdc8 100644
--- a/drivers/media/video/cx23885/cx23885-input.c
+++ b/drivers/media/video/cx23885/cx23885-input.c
@@ -170,7 +170,7 @@ static int cx23885_input_ir_start(struct cx23885_dev *dev)
                  * mark is received as low logic level;
                  * falling edges are detected as rising edges; etc.
                  */
-                params.invert = true;
+                params.invert_level = true;
                 break;
         }
         v4l2_subdev_call(dev->sd_ir, ir, rx_s_parameters, &params);
diff --git a/drivers/media/video/cx23885/cx23888-ir.c b/drivers/media/video/cx23885/cx23888-ir.c
index f63d378257a7..28ca90ff223c 100644
--- a/drivers/media/video/cx23885/cx23888-ir.c
+++ b/drivers/media/video/cx23885/cx23888-ir.c
@@ -60,6 +60,8 @@ MODULE_PARM_DESC(ir_888_debug, "enable debug messages [CX23888 IR controller]");
 #define CNTRL_CPL       0x00001000
 #define CNTRL_LBM       0x00002000
 #define CNTRL_R         0x00004000
+/* CX23888 specific control flag */
+#define CNTRL_IVO       0x00008000
 
 #define CX23888_IR_TXCLK_REG    0x170004
 #define TXCLK_TCD       0x0000FFFF
@@ -423,6 +425,13 @@ static inline void control_tx_polarity_invert(struct cx23885_dev *dev,
                            invert ? CNTRL_CPL : 0);
 }
 
+static inline void control_tx_level_invert(struct cx23885_dev *dev,
+                                          bool invert)
+{
+        cx23888_ir_and_or4(dev, CX23888_IR_CNTRL_REG, ~CNTRL_IVO,
+                           invert ? CNTRL_IVO : 0);
+}
+
 /*
  * IR Rx & Tx Clock Register helpers
  */
@@ -782,8 +791,8 @@ static int cx23888_ir_rx_s_parameters(struct v4l2_subdev *sd,
 
         control_rx_s_edge_detection(dev, CNTRL_EDG_BOTH);
 
-        o->invert = p->invert;
-        atomic_set(&state->rx_invert, p->invert);
+        o->invert_level = p->invert_level;
+        atomic_set(&state->rx_invert, p->invert_level);
 
         o->interrupt_enable = p->interrupt_enable;
         o->enable = p->enable;
@@ -894,8 +903,11 @@ static int cx23888_ir_tx_s_parameters(struct v4l2_subdev *sd,
         /* FIXME - make this dependent on resolution for better performance */
         control_tx_irq_watermark(dev, TX_FIFO_HALF_EMPTY);
 
-        control_tx_polarity_invert(dev, p->invert);
-        o->invert = p->invert;
+        control_tx_polarity_invert(dev, p->invert_carrier_sense);
+        o->invert_carrier_sense = p->invert_carrier_sense;
+
+        control_tx_level_invert(dev, p->invert_level);
+        o->invert_level = p->invert_level;
 
         o->interrupt_enable = p->interrupt_enable;
         o->enable = p->enable;
@@ -1025,8 +1037,11 @@ static int cx23888_ir_log_status(struct v4l2_subdev *sd)
                   cntrl & CNTRL_TFE ? "enabled" : "disabled");
         v4l2_info(sd, "\tFIFO interrupt watermark:          %s\n",
                   cntrl & CNTRL_TIC ? "not empty" : "half full or less");
-        v4l2_info(sd, "\tSignal polarity:                   %s\n",
-                  cntrl & CNTRL_CPL ? "0:mark 1:space" : "0:space 1:mark");
+        v4l2_info(sd, "\tOutput pin level inversion         %s\n",
+                  cntrl & CNTRL_IVO ? "yes" : "no");
+        v4l2_info(sd, "\tCarrier polarity:                  %s\n",
+                  cntrl & CNTRL_CPL ? "space:burst mark:noburst"
+                                    : "space:noburst mark:burst");
         if (cntrl & CNTRL_MOD) {
                 v4l2_info(sd, "\tCarrier (16 clocks):               %u Hz\n",
                           clock_divider_to_carrier_freq(txclk));
@@ -1146,7 +1161,7 @@ static const struct v4l2_subdev_ir_parameters default_rx_params = {
         .noise_filter_min_width = 333333, /* ns */
         .carrier_range_lower = 35000,
         .carrier_range_upper = 37000,
-        .invert = false,
+        .invert_level = false,
 };
 
 static const struct v4l2_subdev_ir_parameters default_tx_params = {
@@ -1160,7 +1175,8 @@ static const struct v4l2_subdev_ir_parameters default_tx_params = {
         .modulation = true,
         .carrier_freq = 36000, /* 36 kHz - RC-5 carrier */
         .duty_cycle = 25,      /* 25 %   - RC-5 carrier */
-        .invert = false,
+        .invert_level = false,
+        .invert_carrier_sense = false,
 };
 
 int cx23888_ir_probe(struct cx23885_dev *dev)