IR support for A83T - sunxi-ir driver update

This patch updates the sunxi-ir driver to set the ir base clock from devicetree.

This is neccessary since there are different ir recievers on the market, that operate with different frequencys. So this value needs to be set depending on the attached receiver.

Signed-off-by Philipp Rossak <[email protected]>

---
 drivers/media/rc/sunxi-cir.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

drivers/media/rc/sunxi-cir.c +0 -0

index 97f367b446c4..55b53d6463e9 100644

drivers/media/rc/sunxi-cir.c +2 -3

-/* Sample period in ns */
-#define SUNXI_IR_SAMPLE       (1000000000ul / SUNXI_IR_CLK)
 /* Noise threshold in samples  */
 #define SUNXI_IR_RXNOISE      1
 /* Idle Threshold in samples */

@@ -122,7 +116,7 @@ static irqreturn_t sunxi_ir_irq(int irqno, void *dev_id)
 			/* for each bit in fifo */
 			dt = readb(ir->base + SUNXI_IR_RXFIFO_REG);
 			rawir.pulse = (dt & 0x80) != 0;
-			rawir.duration = ((dt & 0x7f) + 1) * SUNXI_IR_SAMPLE;
+			rawir.duration = ((dt & 0x7f) + 1) * ir->rc->rx_resolution;
 			ir_raw_event_store_with_filter(ir->rc, &rawir);
 		}
 	}

@@ -148,6 +142,7 @@ static int sunxi_ir_probe(struct platform_device *pdev)
 	struct device_node *dn = dev->of_node;
 	struct resource *res;
 	struct sunxi_ir *ir;
+	u32 b_clk_freq;
 
 	ir = devm_kzalloc(dev, sizeof(struct sunxi_ir), GFP_KERNEL);
 	if (!ir)

drivers/media/rc/sunxi-cir.c +1 -1

 	/* Reset (optional) */
 	ir->rst = devm_reset_control_get_optional_exclusive(dev, NULL);
 	if (IS_ERR(ir->rst))

@@ -180,7 +181,7 @@ static int sunxi_ir_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	ret = clk_set_rate(ir->clk, SUNXI_IR_BASE_CLK);
+	ret = clk_set_rate(ir->clk, b_clk_freq);
 	if (ret) {
 		dev_err(dev, "set ir base clock failed!\n");
 		goto exit_reset_assert;

Em Sat, 16 Dec 2017 03:49:10 +0100
Philipp Rossak <[email protected]> escreveu:

Hi Phillip,

This is not a full review of this patchset. I just want to point you that you should keep supporting existing DT files.

Quoted 6 lines

This patch updates the sunxi-ir driver to set the ir base clock from devicetree.

This is neccessary since there are different ir recievers on the market, that operate with different frequencys. So this value needs to be set depending on the attached receiver.

Please don't break backward compatibility with old DT files. In this specific case, it seems simple enough to be backward-compatible.

Quoted 11 lines

Signed-off-by Philipp Rossak <[email protected]>

---
  drivers/media/rc/sunxi-cir.c | 20 +++++++++++---------
  1 file changed, 11 insertions(+), 9 deletions(-)

drivers/media/rc/sunxi-cir.c +0 -0

index 97f367b446c4..55b53d6463e9 100644

drivers/media/rc/sunxi-cir.c line 78

Quoted 7 lines

drivers/media/rc/sunxi-cir.c +0 -4

@@ -72,12 +72,6 @@
  /* CIR_REG register idle threshold */
  #define REG_CIR_ITHR(val)    (((val) << 8) & (GENMASK(15, 8)))
 
-/* Required frequency for IR0 or IR1 clock in CIR mode */
-#define SUNXI_IR_BASE_CLK     8000000
-/* Frequency after IR internal divider  */
-#define SUNXI_IR_CLK          (SUNXI_IR_BASE_CLK / 64)

Keep those to definitions...

Quoted 23 lines

drivers/media/rc/sunxi-cir.c +2 -3

-/* Sample period in ns */
-#define SUNXI_IR_SAMPLE       (1000000000ul / SUNXI_IR_CLK)
  /* Noise threshold in samples  */
  #define SUNXI_IR_RXNOISE      1
  /* Idle Threshold in samples */

@@ -122,7 +116,7 @@ static irqreturn_t sunxi_ir_irq(int irqno, void *dev_id)
  			/* for each bit in fifo */
  			dt = readb(ir->base + SUNXI_IR_RXFIFO_REG);
  			rawir.pulse = (dt & 0x80) != 0;
-			rawir.duration = ((dt & 0x7f) + 1) * SUNXI_IR_SAMPLE;
+			rawir.duration = ((dt & 0x7f) + 1) * ir->rc->rx_resolution;
  			ir_raw_event_store_with_filter(ir->rc, &rawir);
  		}
  	}

@@ -148,6 +142,7 @@ static int sunxi_ir_probe(struct platform_device *pdev)
  	struct device_node *dn = dev->of_node;
  	struct resource *res;
  	struct sunxi_ir *ir;
+	u32 b_clk_freq;
 
  	ir = devm_kzalloc(dev, sizeof(struct sunxi_ir), GFP_KERNEL);
  	if (!ir)

drivers/media/rc/sunxi-cir.c static int sunxi_ir_probe(struct platform_device *pdev) · line 175

Quoted 9 lines

drivers/media/rc/sunxi-cir.c +6 -0

@@ -172,6 +167,12 @@ static int sunxi_ir_probe(struct platform_device *pdev)
  		return PTR_ERR(ir->clk);
  	}
 
+	/* Required frequency for IR0 or IR1 clock in CIR mode */
+	if (of_property_read_u32(dn, "base-clk-frequency", &b_clk_freq)) {
+		dev_err(dev, "failed to get ir base clock frequency.\n");
+		return -ENODATA;
+	}
+

And here, instead of returning an error, if the property can't be read, it means it is an older DT file. Just default to SUNXI_IR_BASE_CLK. This will make it backward-compatible with old DT files that don't have such property.

Regards,
Mauro

Quoted 13 lines

drivers/media/rc/sunxi-cir.c +1 -1

  	/* Reset (optional) */
  	ir->rst = devm_reset_control_get_optional_exclusive(dev, NULL);
  	if (IS_ERR(ir->rst))

@@ -180,7 +181,7 @@ static int sunxi_ir_probe(struct platform_device *pdev)
  	if (ret)
  		return ret;
 
-	ret = clk_set_rate(ir->clk, SUNXI_IR_BASE_CLK);
+	ret = clk_set_rate(ir->clk, b_clk_freq);
  	if (ret) {
  		dev_err(dev, "set ir base clock failed!\n");
  		goto exit_reset_assert;

drivers/media/rc/sunxi-cir.c static int sunxi_ir_probe(struct platform_device *pdev) · line 233

Quoted 9 lines

drivers/media/rc/sunxi-cir.c +2 -1

@@ -225,7 +226,8 @@ static int sunxi_ir_probe(struct platform_device *pdev)
  	ir->rc->map_name = ir->map_name ?: RC_MAP_EMPTY;
  	ir->rc->dev.parent = dev;
  	ir->rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
-	ir->rc->rx_resolution = SUNXI_IR_SAMPLE;
+	/* Frequency after IR internal divider with sample period in ns */
+	ir->rc->rx_resolution = (1000000000ul / (b_clk_freq / 64));
  	ir->rc->timeout = MS_TO_NS(SUNXI_IR_TIMEOUT);
  	ir->rc->driver_name = SUNXI_IR_DEV;
 

Thanks,
Mauro

This patch updates documentation for Device-Tree bindings for sunxi IR controller and adds the new requiered property for the base clock frequency.

Signed-off-by Philipp Rossak <[email protected]>

---
 Documentation/devicetree/bindings/media/sunxi-ir.txt | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

Documentation/devicetree/bindings/media/sunxi-ir.txt +0 -3

index 91648c569b1e..5f4960c61245 100644
@@ -1,12 +1,13 @@
 Device-Tree bindings for SUNXI IR controller found in sunXi SoC family
 
 Required properties:
-- compatible	    : "allwinner,sun4i-a10-ir" or "allwinner,sun5i-a13-ir"
-- clocks	    : list of clock specifiers, corresponding to
-		      entries in clock-names property;