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[v4] drm/fsl-dcu: Implement gamma_lut atomic crtc properties

Message ID 1475032676-10678-1-git-send-email-meng.yi@nxp.com (mailing list archive)
State New, archived
Headers show

Commit Message

Meng Yi Sept. 28, 2016, 3:17 a.m. UTC
Gamma correction is optional and can be used to adjust the color
output values to match the gamut of a particular TFT LCD panel
Errata:
Gamma_R, Gamma_G and Gamma_B registers are little-endian registers
while the rest of the address-space in 2D-ACE is big-endian.
Workaround:
Split the DCU regs into "regs", "palette", "gamma" and "cursor".
Create a second regmap for gamma memory space using little endian.

Suggested-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Meng Yi <meng.yi@nxp.com>
---
Changes since V1:
-created a second regmap for gamma
-updated the DCU DT binding
-removed Kconfig for gamma and enable gamma when valid data filled.
---
 .../devicetree/bindings/display/fsl,dcu.txt        | 15 +++++++++-
 drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c         | 32 ++++++++++++++++++++
 drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c          | 35 +++++++++++++++++++++-
 drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h          |  7 +++++
 4 files changed, 87 insertions(+), 2 deletions(-)
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/display/fsl,dcu.txt b/Documentation/devicetree/bindings/display/fsl,dcu.txt
index 63ec2a6..e3cf2de 100644
--- a/Documentation/devicetree/bindings/display/fsl,dcu.txt
+++ b/Documentation/devicetree/bindings/display/fsl,dcu.txt
@@ -6,6 +6,15 @@  Required properties:
 	* "fsl,vf610-dcu".
 
 - reg:			Address and length of the register set for dcu.
+			Parameter                        Address Range
+
+			Register address space           0x0000 – 0x1FFF
+			Palette/Tile address space       0x2000 – 0x3FFF
+			Gamma_R address space            0x4000 – 0x43FF
+			Gamma_G address space            0x4400 – 0x47FF
+			Gamma_B address space            0x4800 – 0x4BFF
+			Cursor address space             0x4C00 – 0x4FFF
+
 - clocks:		Handle to "dcu" and "pix" clock (in the order below)
 			This can be the same clock (e.g. LS1021a)
 			See ../clocks/clock-bindings.txt for details.
@@ -20,7 +29,11 @@  Optional properties:
 Examples:
 dcu: dcu@2ce0000 {
 	compatible = "fsl,ls1021a-dcu";
-	reg = <0x0 0x2ce0000 0x0 0x10000>;
+	reg = <0x0 0x2ce0000 0x0 0x2000>,
+	      <0x0 0x2ce2000 0x0 0x2000>,
+	      <0x0 0x2ce4000 0x0 0xc00>,
+	      <0x0 0x2ce4c00 0x0 0x400>;
+	reg-names = "regs", "palette", "gamma", "cursor";
 	clocks = <&platform_clk 0>, <&platform_clk 0>;
 	clock-names = "dcu", "pix";
 	big-endian;
diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c
index 3371635..4ff969b 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c
@@ -22,6 +22,30 @@ 
 #include "fsl_dcu_drm_drv.h"
 #include "fsl_dcu_drm_plane.h"
 
+static void fsl_crtc_gamma_set(struct drm_crtc *crtc, struct drm_color_lut *lut,
+			      uint32_t size)
+{
+	struct fsl_dcu_drm_device *fsl_dev = crtc->dev->dev_private;
+	unsigned int i;
+
+	if (crtc->state->gamma_lut->data) {
+		for (i = 0; i < size; i++) {
+			regmap_write(fsl_dev->regmap_gamma, FSL_GAMMA_R + 4 * i,
+				     lut[i].red);
+			regmap_write(fsl_dev->regmap_gamma, FSL_GAMMA_G + 4 * i,
+				     lut[i].green);
+			regmap_write(fsl_dev->regmap_gamma, FSL_GAMMA_B + 4 * i,
+				     lut[i].blue);
+		}
+
+		regmap_update_bits(fsl_dev->regmap, DCU_DCU_MODE,
+				   DCU_MODE_EN_GAMMA_MASK,
+				   DCU_MODE_GAMMA_ENABLE);
+	} else
+		regmap_update_bits(fsl_dev->regmap, DCU_DCU_MODE,
+				   DCU_MODE_EN_GAMMA_MASK, 0);
+}
+
 static void fsl_dcu_drm_crtc_atomic_flush(struct drm_crtc *crtc,
 					  struct drm_crtc_state *old_crtc_state)
 {
@@ -37,6 +61,10 @@  static void fsl_dcu_drm_crtc_atomic_flush(struct drm_crtc *crtc,
 			drm_crtc_send_vblank_event(crtc, event);
 		spin_unlock_irq(&crtc->dev->event_lock);
 	}
+
+	if (crtc->state->color_mgmt_changed && crtc->state->gamma_lut)
+		fsl_crtc_gamma_set(crtc, (struct drm_color_lut *)
+				   crtc->state->gamma_lut->data, 256);
 }
 
 static void fsl_dcu_drm_disable_crtc(struct drm_crtc *crtc)
@@ -135,6 +163,7 @@  static const struct drm_crtc_funcs fsl_dcu_drm_crtc_funcs = {
 	.page_flip = drm_atomic_helper_page_flip,
 	.reset = drm_atomic_helper_crtc_reset,
 	.set_config = drm_atomic_helper_set_config,
+	.gamma_set = drm_atomic_helper_legacy_gamma_set,
 };
 
 int fsl_dcu_drm_crtc_create(struct fsl_dcu_drm_device *fsl_dev)
@@ -158,5 +187,8 @@  int fsl_dcu_drm_crtc_create(struct fsl_dcu_drm_device *fsl_dev)
 
 	drm_crtc_helper_add(crtc, &fsl_dcu_drm_crtc_helper_funcs);
 
+	drm_crtc_enable_color_mgmt(crtc, 0, false, 256);
+	drm_mode_crtc_set_gamma_size(crtc, 256);
+
 	return 0;
 }
diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
index 092aaec..e662890 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
@@ -48,6 +48,20 @@  static const struct regmap_config fsl_dcu_regmap_config = {
 	.volatile_reg = fsl_dcu_drm_is_volatile_reg,
 };
 
+/*
+ * force using little endian here since ls1021a's gamma regs are little
+ * endian while the other regs are big endian, and all vf610s's regs
+ * are little endian
+ */
+static const struct regmap_config fsl_dcu_regmap_gamma_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.val_format_endian = REGMAP_ENDIAN_LITTLE,
+
+	.volatile_reg = fsl_dcu_drm_is_volatile_reg,
+};
+
 static int fsl_dcu_drm_irq_init(struct drm_device *dev)
 {
 	struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
@@ -327,7 +341,7 @@  static int fsl_dcu_drm_probe(struct platform_device *pdev)
 	struct drm_device *drm;
 	struct device *dev = &pdev->dev;
 	struct resource *res;
-	void __iomem *base;
+	void __iomem *base, *base_gamma;
 	struct drm_driver *driver = &fsl_dcu_drm_driver;
 	struct clk *pix_clk_in;
 	char pix_clk_name[32];
@@ -370,6 +384,25 @@  static int fsl_dcu_drm_probe(struct platform_device *pdev)
 		return PTR_ERR(fsl_dev->regmap);
 	}
 
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "gamma");
+	if (!res) {
+		dev_err(dev, "could not get gamma memory resource\n");
+		return -ENODEV;
+	}
+
+	base_gamma = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base_gamma)) {
+		ret = PTR_ERR(base_gamma);
+		return ret;
+	}
+
+	fsl_dev->regmap_gamma = devm_regmap_init_mmio(dev, base_gamma,
+			&fsl_dcu_regmap_gamma_config);
+	if (IS_ERR(fsl_dev->regmap_gamma)) {
+		dev_err(dev, "regmap_gamma init failed\n");
+		return PTR_ERR(fsl_dev->regmap_gamma);
+	}
+
 	fsl_dev->clk = devm_clk_get(dev, "dcu");
 	if (IS_ERR(fsl_dev->clk)) {
 		dev_err(dev, "failed to get dcu clock\n");
diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
index 3b371fe7..2610b6c 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
@@ -25,6 +25,8 @@ 
 #define DCU_MODE_NORMAL			1
 #define DCU_MODE_TEST			2
 #define DCU_MODE_COLORBAR		3
+#define DCU_MODE_EN_GAMMA_MASK		0x04
+#define DCU_MODE_GAMMA_ENABLE		BIT(2)
 
 #define DCU_BGND			0x0014
 #define DCU_BGND_R(x)			((x) << 16)
@@ -165,6 +167,10 @@ 
 #define VF610_LAYER_REG_NUM		9
 #define LS1021A_LAYER_REG_NUM		10
 
+#define FSL_GAMMA_R			0x000
+#define FSL_GAMMA_G			0x400
+#define FSL_GAMMA_B			0x800
+
 struct clk;
 struct device;
 struct drm_device;
@@ -182,6 +188,7 @@  struct fsl_dcu_drm_device {
 	struct device *dev;
 	struct device_node *np;
 	struct regmap *regmap;
+	struct regmap *regmap_gamma;
 	int irq;
 	struct clk *clk;
 	struct clk *pix_clk;