[PATCH v2 24/30] dm: core: add a function to decode display timings

Dario Binacchi dariobin at libero.it
Sun Sep 6 14:11:54 CEST 2020


The patch adds a function to get display timings from the device tree
node attached to the device.

Signed-off-by: Dario Binacchi <dariobin at libero.it>
Reviewed-by: Simon Glass <sjg at chromium.org>
---

(no changes since v1)

 arch/sandbox/dts/test.dts | 46 ++++++++++++++++++++++
 drivers/core/read.c       |  6 +++
 include/dm/read.h         | 24 ++++++++++++
 test/dm/test-fdt.c        | 80 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 156 insertions(+)

diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index af701d2086..03626ab289 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -129,6 +129,52 @@
 		str-value = "test string";
 		interrupts-extended = <&irq 3 0>;
 		acpi,name = "GHIJ";
+		display-timings {
+			timing0: 240x320 {
+				clock-frequency = <6500000>;
+				hactive = <240>;
+				vactive = <320>;
+				hfront-porch = <6>;
+				hback-porch = <7>;
+				hsync-len = <1>;
+				vback-porch = <5>;
+				vfront-porch = <8>;
+				vsync-len = <2>;
+				hsync-active = <1>;
+				vsync-active = <0>;
+				de-active = <1>;
+				pixelclk-active = <1>;
+				interlaced;
+				doublescan;
+				doubleclk;
+			};
+			timing1: 480x800 {
+				clock-frequency = <9000000>;
+				hactive = <480>;
+				vactive = <800>;
+				hfront-porch = <10>;
+				hback-porch = <59>;
+				hsync-len = <12>;
+				vback-porch = <15>;
+				vfront-porch = <17>;
+				vsync-len = <16>;
+				hsync-active = <0>;
+				vsync-active = <1>;
+				de-active = <0>;
+				pixelclk-active = <0>;
+			};
+			timing2: 800x480 {
+				clock-frequency = <33500000>;
+				hactive = <800>;
+				vactive = <480>;
+				hback-porch = <89>;
+				hfront-porch = <164>;
+				vback-porch = <23>;
+				vfront-porch = <10>;
+				hsync-len = <11>;
+				vsync-len = <13>;
+			};
+		};
 	};
 
 	junk {
diff --git a/drivers/core/read.c b/drivers/core/read.c
index 86f3f88170..f4fc0fa345 100644
--- a/drivers/core/read.c
+++ b/drivers/core/read.c
@@ -376,3 +376,9 @@ int dev_read_pci_bus_range(const struct udevice *dev,
 
 	return 0;
 }
+
+int dev_decode_display_timing(const struct udevice *dev, int index,
+			      struct display_timing *config)
+{
+	return ofnode_decode_display_timing(dev_ofnode(dev), index, config);
+}
diff --git a/include/dm/read.h b/include/dm/read.h
index 67db94adfc..a8d3f13198 100644
--- a/include/dm/read.h
+++ b/include/dm/read.h
@@ -692,6 +692,23 @@ int dev_get_child_count(const struct udevice *dev);
  */
 int dev_read_pci_bus_range(const struct udevice *dev, struct resource *res);
 
+/**
+ * dev_decode_display_timing() - decode display timings
+ *
+ * Decode display timings from the supplied 'display-timings' node.
+ * See doc/device-tree-bindings/video/display-timing.txt for binding
+ * information.
+ *
+ * @dev: device to read DT display timings from. The node linked to the device
+ *       contains a child node called 'display-timings' which in turn contains
+ *       one or more display timing nodes.
+ * @index: index number to read (0=first timing subnode)
+ * @config: place to put timings
+ * @return 0 if OK, -FDT_ERR_NOTFOUND if not found
+ */
+int dev_decode_display_timing(const struct udevice *dev, int index,
+			      struct display_timing *config);
+
 #else /* CONFIG_DM_DEV_READ_INLINE is enabled */
 
 static inline int dev_read_u32(const struct udevice *dev,
@@ -1014,6 +1031,13 @@ static inline int dev_get_child_count(const struct udevice *dev)
 	return ofnode_get_child_count(dev_ofnode(dev));
 }
 
+static inline int dev_decode_display_timing(const struct udevice *dev,
+					    int index,
+					    struct display_timing *config)
+{
+	return ofnode_decode_display_timing(dev_ofnode(dev), index, config);
+}
+
 #endif /* CONFIG_DM_DEV_READ_INLINE */
 
 /**
diff --git a/test/dm/test-fdt.c b/test/dm/test-fdt.c
index 632f388d02..219e6c1031 100644
--- a/test/dm/test-fdt.c
+++ b/test/dm/test-fdt.c
@@ -1117,3 +1117,83 @@ static int dm_test_ofdata_order(struct unit_test_state *uts)
 	return 0;
 }
 DM_TEST(dm_test_ofdata_order, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);
+
+/* Test dev_decode_display_timing() */
+static int dm_test_decode_display_timing(struct unit_test_state *uts)
+{
+	struct udevice *dev;
+	struct display_timing timing;
+
+	ut_assertok(uclass_first_device_err(UCLASS_TEST_FDT, &dev));
+	ut_asserteq_str("a-test", dev->name);
+
+	ut_assertok(dev_decode_display_timing(dev, 0, &timing));
+	ut_assert(timing.hactive.typ == 240);
+	ut_assert(timing.hback_porch.typ == 7);
+	ut_assert(timing.hfront_porch.typ == 6);
+	ut_assert(timing.hsync_len.typ == 1);
+	ut_assert(timing.vactive.typ == 320);
+	ut_assert(timing.vback_porch.typ == 5);
+	ut_assert(timing.vfront_porch.typ == 8);
+	ut_assert(timing.vsync_len.typ == 2);
+	ut_assert(timing.pixelclock.typ == 6500000);
+	ut_assert(timing.flags & DISPLAY_FLAGS_HSYNC_HIGH);
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_HSYNC_LOW));
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_VSYNC_HIGH));
+	ut_assert(timing.flags & DISPLAY_FLAGS_VSYNC_LOW);
+	ut_assert(timing.flags & DISPLAY_FLAGS_DE_HIGH);
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_DE_LOW));
+	ut_assert(timing.flags & DISPLAY_FLAGS_PIXDATA_POSEDGE);
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE));
+	ut_assert(timing.flags & DISPLAY_FLAGS_INTERLACED);
+	ut_assert(timing.flags & DISPLAY_FLAGS_DOUBLESCAN);
+	ut_assert(timing.flags & DISPLAY_FLAGS_DOUBLECLK);
+
+	ut_assertok(dev_decode_display_timing(dev, 1, &timing));
+	ut_assert(timing.hactive.typ == 480);
+	ut_assert(timing.hback_porch.typ == 59);
+	ut_assert(timing.hfront_porch.typ == 10);
+	ut_assert(timing.hsync_len.typ == 12);
+	ut_assert(timing.vactive.typ == 800);
+	ut_assert(timing.vback_porch.typ == 15);
+	ut_assert(timing.vfront_porch.typ == 17);
+	ut_assert(timing.vsync_len.typ == 16);
+	ut_assert(timing.pixelclock.typ == 9000000);
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_HSYNC_HIGH));
+	ut_assert(timing.flags & DISPLAY_FLAGS_HSYNC_LOW);
+	ut_assert(timing.flags & DISPLAY_FLAGS_VSYNC_HIGH);
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_VSYNC_LOW));
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_DE_HIGH));
+	ut_assert(timing.flags & DISPLAY_FLAGS_DE_LOW);
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_PIXDATA_POSEDGE));
+	ut_assert(timing.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE);
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_INTERLACED));
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_DOUBLESCAN));
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_DOUBLECLK));
+
+	ut_assertok(dev_decode_display_timing(dev, 2, &timing));
+	ut_assert(timing.hactive.typ == 800);
+	ut_assert(timing.hback_porch.typ == 89);
+	ut_assert(timing.hfront_porch.typ == 164);
+	ut_assert(timing.hsync_len.typ == 11);
+	ut_assert(timing.vactive.typ == 480);
+	ut_assert(timing.vback_porch.typ == 23);
+	ut_assert(timing.vfront_porch.typ == 10);
+	ut_assert(timing.vsync_len.typ == 13);
+	ut_assert(timing.pixelclock.typ == 33500000);
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_HSYNC_HIGH));
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_HSYNC_LOW));
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_VSYNC_HIGH));
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_VSYNC_LOW));
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_DE_HIGH));
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_DE_LOW));
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_PIXDATA_POSEDGE));
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE));
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_INTERLACED));
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_DOUBLESCAN));
+	ut_assert(!(timing.flags & DISPLAY_FLAGS_DOUBLECLK));
+
+	ut_assert(dev_decode_display_timing(dev, 3, &timing));
+	return 0;
+}
+DM_TEST(dm_test_decode_display_timing, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);
-- 
2.17.1



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