3 files changed, 143 insertions, 1 deletions

diff --git a/Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt b/Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt
index abe9e9d8b785..b95696d748c7 100644
--- a/Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt
+++ b/Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt
@@ -53,6 +53,30 @@ Required properties:
 On the A13, there is one more clock required:
    - 'tcon-ch1': The clock driving the TCON channel 1
 
+DRC
+---
+
+The DRC (Dynamic Range Controller), found in the latest Allwinner SoCs
+(A31, A23, A33), allows to dynamically adjust pixel
+brightness/contrast based on histogram measurements for LCD content
+adaptive backlight control.
+
+
+Required properties:
+  - compatible: value must be one of:
+    * allwinner,sun8i-a33-drc
+  - reg: base address and size of the memory-mapped region.
+  - interrupts: interrupt associated to this IP
+  - clocks: phandles to the clocks feeding the DRC
+    * ahb: the DRC interface clock
+    * mod: the DRC module clock
+    * ram: the DRC DRAM clock
+  - clock-names: the clock names mentioned above
+  - resets: phandles to the reset line driving the DRC
+
+- ports: A ports node with endpoint definitions as defined in
+  Documentation/devicetree/bindings/media/video-interfaces.txt. The
+  first port should be the input endpoints, the second one the outputs
 
 Display Engine Backend
 ----------------------
diff --git a/drivers/gpu/drm/sun4i/Makefile b/drivers/gpu/drm/sun4i/Makefile
index 58cd55149827..d625a82a6e5f 100644
--- a/drivers/gpu/drm/sun4i/Makefile
+++ b/drivers/gpu/drm/sun4i/Makefile
@@ -9,5 +9,5 @@ sun4i-tcon-y += sun4i_dotclock.o
 
 obj-$(CONFIG_DRM_SUN4I)		+= sun4i-drm.o sun4i-tcon.o
 obj-$(CONFIG_DRM_SUN4I)		+= sun4i_backend.o
-
+obj-$(CONFIG_DRM_SUN4I)		+= sun6i_drc.o
 obj-$(CONFIG_DRM_SUN4I)		+= sun4i_tv.o
diff --git a/drivers/gpu/drm/sun4i/sun6i_drc.c b/drivers/gpu/drm/sun4i/sun6i_drc.c
new file mode 100644
index 000000000000..bf6d846d8132
--- /dev/null
+++ b/drivers/gpu/drm/sun4i/sun6i_drc.c
@@ -0,0 +1,118 @@
+/*
+ * Copyright (C) 2016 Free Electrons
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * 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 the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ */
+
+#include <linux/clk.h>
+#include <linux/component.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+
+struct sun6i_drc {
+	struct clk		*bus_clk;
+	struct clk		*mod_clk;
+	struct reset_control	*reset;
+};
+
+static int sun6i_drc_bind(struct device *dev, struct device *master,
+			 void *data)
+{
+	struct sun6i_drc *drc;
+	int ret;
+
+	drc = devm_kzalloc(dev, sizeof(*drc), GFP_KERNEL);
+	if (!drc)
+		return -ENOMEM;
+	dev_set_drvdata(dev, drc);
+
+	drc->reset = devm_reset_control_get(dev, NULL);
+	if (IS_ERR(drc->reset)) {
+		dev_err(dev, "Couldn't get our reset line\n");
+		return PTR_ERR(drc->reset);
+	}
+
+	ret = reset_control_deassert(drc->reset);
+	if (ret) {
+		dev_err(dev, "Couldn't deassert our reset line\n");
+		return ret;
+	}
+
+	drc->bus_clk = devm_clk_get(dev, "ahb");
+	if (IS_ERR(drc->bus_clk)) {
+		dev_err(dev, "Couldn't get our bus clock\n");
+		ret = PTR_ERR(drc->bus_clk);
+		goto err_assert_reset;
+	}
+	clk_prepare_enable(drc->bus_clk);
+
+	drc->mod_clk = devm_clk_get(dev, "mod");
+	if (IS_ERR(drc->mod_clk)) {
+		dev_err(dev, "Couldn't get our mod clock\n");
+		ret = PTR_ERR(drc->mod_clk);
+		goto err_disable_bus_clk;
+	}
+	clk_prepare_enable(drc->mod_clk);
+
+	return 0;
+
+err_disable_bus_clk:
+	clk_disable_unprepare(drc->bus_clk);
+err_assert_reset:
+	reset_control_assert(drc->reset);
+	return ret;
+}
+
+static void sun6i_drc_unbind(struct device *dev, struct device *master,
+			    void *data)
+{
+	struct sun6i_drc *drc = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(drc->mod_clk);
+	clk_disable_unprepare(drc->bus_clk);
+	reset_control_assert(drc->reset);
+}
+
+static struct component_ops sun6i_drc_ops = {
+	.bind	= sun6i_drc_bind,
+	.unbind	= sun6i_drc_unbind,
+};
+
+static int sun6i_drc_probe(struct platform_device *pdev)
+{
+	return component_add(&pdev->dev, &sun6i_drc_ops);
+}
+
+static int sun6i_drc_remove(struct platform_device *pdev)
+{
+	component_del(&pdev->dev, &sun6i_drc_ops);
+
+	return 0;
+}
+
+static const struct of_device_id sun6i_drc_of_table[] = {
+	{ .compatible = "allwinner,sun8i-a33-drc" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sun6i_drc_of_table);
+
+static struct platform_driver sun6i_drc_platform_driver = {
+	.probe		= sun6i_drc_probe,
+	.remove		= sun6i_drc_remove,
+	.driver		= {
+		.name		= "sun6i-drc",
+		.of_match_table	= sun6i_drc_of_table,
+	},
+};
+module_platform_driver(sun6i_drc_platform_driver);
+
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
+MODULE_DESCRIPTION("Allwinner A31 Dynamic Range Control (DRC) Driver");
+MODULE_LICENSE("GPL");