[PATCH v7 0/7] drm: rcar-du: Add Color Management Module (CMM)

[PATCH v7 0/7] drm: rcar-du: Add Color Management Module (CMM)

[Jacopo Mondi]

An additional round for cmm to fix the KConfig issue reported by Dave spotted
while collecting Laurent's pull request for the v5.5 merge window, which we've
now missed.

I could have sent a 6.2 version of the single 3/7 patch, but given I already
sent a 6.1 for this same one, I assumed a single series would have been
easier to collect, considering we're anyway late for this merge window.

The DTS patches have been collected by Geert already.

Thanks
   j

Detailed v1->v5 change log
https://lkml.org/lkml/2019/10/15/337

v6->v7
- Include the two updates for 3/7 and 5/7 I've sent as v6.1 against the v6
  series
- Make the DRM_RCAR_CMM symbol a tristate and make it implied by DRM_RCAR_DU
  to prevent having DU built-in and CMM has a module, which causes linkage
  errors due to unresolved symbols.

Jacopo Mondi (7):
  dt-bindings: display: renesas,cmm: Add R-Car CMM documentation
  dt-bindings: display, renesas,du: Document cmms property
  drm: rcar-du: Add support for CMM
  drm: rcar-du: kms: Initialize CMM instances
  drm: rcar-du: crtc: Control CMM operations
  drm: rcar-du: crtc: Register GAMMA_LUT properties
  drm: rcar-du: kms: Expand comment in vsps parsing routine

 .../bindings/display/renesas,cmm.yaml         |  67 ++++++
 .../bindings/display/renesas,du.txt           |   5 +
 drivers/gpu/drm/rcar-du/Kconfig               |   8 +
 drivers/gpu/drm/rcar-du/Makefile              |   1 +
 drivers/gpu/drm/rcar-du/rcar_cmm.c            | 212 ++++++++++++++++++
 drivers/gpu/drm/rcar-du/rcar_cmm.h            |  58 +++++
 drivers/gpu/drm/rcar-du/rcar_du_crtc.c        |  65 ++++++
 drivers/gpu/drm/rcar-du/rcar_du_crtc.h        |   2 +
 drivers/gpu/drm/rcar-du/rcar_du_drv.h         |   2 +
 drivers/gpu/drm/rcar-du/rcar_du_group.c       |  10 +
 drivers/gpu/drm/rcar-du/rcar_du_group.h       |   2 +
 drivers/gpu/drm/rcar-du/rcar_du_kms.c         |  82 ++++++-
 drivers/gpu/drm/rcar-du/rcar_du_regs.h        |   5 +
 13 files changed, 518 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/display/renesas,cmm.yaml
 create mode 100644 drivers/gpu/drm/rcar-du/rcar_cmm.c
 create mode 100644 drivers/gpu/drm/rcar-du/rcar_cmm.h

--
2.23.0

[PATCH v7 1/7] dt-bindings: display: renesas,cmm: Add R-Car CMM documentation

[Jacopo Mondi]

Add device tree bindings documentation for the Renesas R-Car Display
Unit Color Management Module.

CMM is the image enhancement module available on each R-Car DU video
channel on R-Car Gen2 and Gen3 SoCs (V3H and V3M excluded).

Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
---
 .../bindings/display/renesas,cmm.yaml         | 67 +++++++++++++++++++
 1 file changed, 67 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/renesas,cmm.yaml

diff --git a/Documentation/devicetree/bindings/display/renesas,cmm.yaml b/Documentation/devicetree/bindings/display/renesas,cmm.yaml
new file mode 100644
index 000000000000..a57037b9e9ba
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/renesas,cmm.yaml
@@ -0,0 +1,67 @@
+# SPDX-License-Identifier: GPL-2.0-only
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/renesas,cmm.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas R-Car Color Management Module (CMM)
+
+maintainers:
+  - Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+  - Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
+  - Jacopo Mondi <jacopo+renesas@jmondi.org>
+
+description: |+
+  Renesas R-Car color management module connected to R-Car DU video channels.
+  It provides image enhancement functions such as 1-D look-up tables (LUT),
+  3-D look-up tables (CLU), 1D-histogram generation (HGO), and color
+  space conversion (CSC).
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+        - enum:
+          - renesas,r8a7795-cmm
+          - renesas,r8a7796-cmm
+          - renesas,r8a77965-cmm
+          - renesas,r8a77990-cmm
+          - renesas,r8a77995-cmm
+        - const: renesas,rcar-gen3-cmm
+      - items:
+        - const: renesas,rcar-gen2-cmm
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+  power-domains:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - resets
+  - power-domains
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/r8a7796-cpg-mssr.h>
+    #include <dt-bindings/power/r8a7796-sysc.h>
+
+    cmm0: cmm@fea40000 {
+         compatible = "renesas,r8a7796-cmm",
+                      "renesas,rcar-gen3-cmm";
+         reg = <0 0xfea40000 0 0x1000>;
+         power-domains = <&sysc R8A7796_PD_ALWAYS_ON>;
+         clocks = <&cpg CPG_MOD 711>;
+         resets = <&cpg 711>;
+    };
-- 
2.23.0

[PATCH v7 2/7] dt-bindings: display, renesas,du: Document cmms property

[Jacopo Mondi]

Document the newly added 'cmms' property which accepts a list of phandle
and channel index pairs that point to the CMM units available for each
Display Unit output video channel.

Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
---
 Documentation/devicetree/bindings/display/renesas,du.txt | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/renesas,du.txt b/Documentation/devicetree/bindings/display/renesas,du.txt
index c97dfacad281..3d9809b486b6 100644
--- a/Documentation/devicetree/bindings/display/renesas,du.txt
+++ b/Documentation/devicetree/bindings/display/renesas,du.txt
@@ -45,6 +45,10 @@ Required Properties:
     instance that serves the DU channel, and the channel index identifies the
     LIF instance in that VSP.
 
+  - renesas,cmms: A list of phandles to the CMM instances present in the SoC,
+    one for each available DU channel. The property shall not be specified for
+    SoCs that do not provide any CMM (such as V3M and V3H).
+
 Required nodes:
 
 The connections to the DU output video ports are modeled using the OF graph
@@ -91,6 +95,7 @@ Example: R8A7795 (R-Car H3) ES2.0 DU
 			 <&cpg CPG_MOD 721>;
 		clock-names = "du.0", "du.1", "du.2", "du.3";
 		vsps = <&vspd0 0>, <&vspd1 0>, <&vspd2 0>, <&vspd0 1>;
+		renesas,cmms = <&cmm0>, <&cmm1>, <&cmm2>, <&cmm3>;
 
 		ports {
 			#address-cells = <1>;
-- 
2.23.0

Re: [PATCH v7 2/7] dt-bindings: display, renesas,du: Document cmms property

[Geert Uytterhoeven]

Hi Jacopo,

Sorry for spoiling your v7 ;-)

On Wed, Nov 13, 2019 at 11:04 AM Jacopo Mondi <jacopo+renesas@jmondi.org> wrote:
> Document the newly added 'cmms' property which accepts a list of phandle

renesas,cmms

> and channel index pairs that point to the CMM units available for each
> Display Unit output video channel.
>
> Reviewed-by: Rob Herring <robh@kernel.org>
> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v7 2/7] dt-bindings: display, renesas,du: Document cmms property

[Laurent Pinchart]

On Wed, Nov 13, 2019 at 02:34:27PM +0100, Geert Uytterhoeven wrote:
> Hi Jacopo,
> 
> Sorry for spoiling your v7 ;-)
> 
> On Wed, Nov 13, 2019 at 11:04 AM Jacopo Mondi <jacopo+renesas@jmondi.org> wrote:
> > Document the newly added 'cmms' property which accepts a list of phandle
> 
> renesas,cmms

Fix applied to my branch.

> > and channel index pairs that point to the CMM units available for each
> > Display Unit output video channel.
> >
> > Reviewed-by: Rob Herring <robh@kernel.org>
> > Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>

-- 
Regards,

Laurent Pinchart

[PATCH v7 3/7] drm: rcar-du: Add support for CMM

[Jacopo Mondi]

Add a driver for the R-Car Display Unit Color Correction Module.

In most of Gen3 SoCs, each DU output channel is provided with a CMM unit
to perform image enhancement and color correction.

Add support for CMM through a driver that supports configuration of
the 1-dimensional LUT table. More advanced CMM features will be
implemented on top of this initial one.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>

---
v6 -> v7
- Expand rcar_cmm_setup() function documentation to detail its relationship
  with rcar_cmm_enable() and their call order precedence.

- Kconfig update: Make DRM_RCAR_CMM a tristate option and 'imply' it from the
  RCAR_DU one. This guarantees that if DU is built as a module CMM can only be
  built as a module as well. At the same time, if DU is built-in, CMM can
  be built-in only.
---
 drivers/gpu/drm/rcar-du/Kconfig    |   8 ++
 drivers/gpu/drm/rcar-du/Makefile   |   1 +
 drivers/gpu/drm/rcar-du/rcar_cmm.c | 217 +++++++++++++++++++++++++++++
 drivers/gpu/drm/rcar-du/rcar_cmm.h |  58 ++++++++
 4 files changed, 284 insertions(+)
 create mode 100644 drivers/gpu/drm/rcar-du/rcar_cmm.c
 create mode 100644 drivers/gpu/drm/rcar-du/rcar_cmm.h

diff --git a/drivers/gpu/drm/rcar-du/Kconfig b/drivers/gpu/drm/rcar-du/Kconfig
index 1529849e217e..6ed7a4f3c44e 100644
--- a/drivers/gpu/drm/rcar-du/Kconfig
+++ b/drivers/gpu/drm/rcar-du/Kconfig
@@ -5,6 +5,7 @@ config DRM_RCAR_DU
 	depends on ARM || ARM64
 	depends on ARCH_RENESAS || COMPILE_TEST
 	imply DRM_RCAR_LVDS
+	imply DRM_RCAR_CMM
 	select DRM_KMS_HELPER
 	select DRM_KMS_CMA_HELPER
 	select DRM_GEM_CMA_HELPER
@@ -13,6 +14,13 @@ config DRM_RCAR_DU
 	  Choose this option if you have an R-Car chipset.
 	  If M is selected the module will be called rcar-du-drm.

+config DRM_RCAR_CMM
+	tristate "R-Car DU Color Management Module (CMM) Support"
+	depends on DRM && OF
+	depends on DRM_RCAR_DU
+	help
+	  Enable support for R-Car Color Management Module (CMM).
+
 config DRM_RCAR_DW_HDMI
 	tristate "R-Car DU Gen3 HDMI Encoder Support"
 	depends on DRM && OF
diff --git a/drivers/gpu/drm/rcar-du/Makefile b/drivers/gpu/drm/rcar-du/Makefile
index 6c2ed9c46467..4d1187ccc3e5 100644
--- a/drivers/gpu/drm/rcar-du/Makefile
+++ b/drivers/gpu/drm/rcar-du/Makefile
@@ -15,6 +15,7 @@ rcar-du-drm-$(CONFIG_DRM_RCAR_LVDS)	+= rcar_du_of.o \
 rcar-du-drm-$(CONFIG_DRM_RCAR_VSP)	+= rcar_du_vsp.o
 rcar-du-drm-$(CONFIG_DRM_RCAR_WRITEBACK) += rcar_du_writeback.o

+obj-$(CONFIG_DRM_RCAR_CMM)		+= rcar_cmm.o
 obj-$(CONFIG_DRM_RCAR_DU)		+= rcar-du-drm.o
 obj-$(CONFIG_DRM_RCAR_DW_HDMI)		+= rcar_dw_hdmi.o
 obj-$(CONFIG_DRM_RCAR_LVDS)		+= rcar_lvds.o
diff --git a/drivers/gpu/drm/rcar-du/rcar_cmm.c b/drivers/gpu/drm/rcar-du/rcar_cmm.c
new file mode 100644
index 000000000000..c578095b09a5
--- /dev/null
+++ b/drivers/gpu/drm/rcar-du/rcar_cmm.c
@@ -0,0 +1,217 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * rcar_cmm.c -- R-Car Display Unit Color Management Module
+ *
+ * Copyright (C) 2019 Jacopo Mondi <jacopo+renesas@jmondi.org>
+ */
+
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+#include <drm/drm_color_mgmt.h>
+
+#include "rcar_cmm.h"
+
+#define CM2_LUT_CTRL		0x0000
+#define CM2_LUT_CTRL_LUT_EN	BIT(0)
+#define CM2_LUT_TBL_BASE	0x0600
+#define CM2_LUT_TBL(__i)	(CM2_LUT_TBL_BASE + (__i) * 4)
+
+struct rcar_cmm {
+	void __iomem *base;
+
+	/*
+	 * @lut:		1D-LUT state
+	 * @lut.enabled:	1D-LUT enabled flag
+	 */
+	struct {
+		bool enabled;
+	} lut;
+};
+
+static inline int rcar_cmm_read(struct rcar_cmm *rcmm, u32 reg)
+{
+	return ioread32(rcmm->base + reg);
+}
+
+static inline void rcar_cmm_write(struct rcar_cmm *rcmm, u32 reg, u32 data)
+{
+	iowrite32(data, rcmm->base + reg);
+}
+
+/*
+ * rcar_cmm_lut_write() - Scale the DRM LUT table entries to hardware precision
+ *			  and write to the CMM registers
+ * @rcmm: Pointer to the CMM device
+ * @drm_lut: Pointer to the DRM LUT table
+ */
+static void rcar_cmm_lut_write(struct rcar_cmm *rcmm,
+			       const struct drm_color_lut *drm_lut)
+{
+	unsigned int i;
+
+	for (i = 0; i < CM2_LUT_SIZE; ++i) {
+		u32 entry = drm_color_lut_extract(drm_lut[i].red, 8) << 16
+			  | drm_color_lut_extract(drm_lut[i].green, 8) << 8
+			  | drm_color_lut_extract(drm_lut[i].blue, 8);
+
+		rcar_cmm_write(rcmm, CM2_LUT_TBL(i), entry);
+	}
+}
+
+/*
+ * rcar_cmm_setup() - Configure the CMM unit
+ * @pdev: The platform device associated with the CMM instance
+ * @config: The CMM unit configuration
+ *
+ * Configure the CMM unit with the given configuration. Currently enabling,
+ * disabling and programming of the 1-D LUT unit is supported.
+ *
+ * As rcar_cmm_setup() accesses the CMM registers the unit should be powered
+ * and its functional clock enabled. To guarantee this, before any call to
+ * this function is made, the CMM unit has to be enabled by calling
+ * rcar_cmm_enable() first.
+ *
+ * TODO: Add support for LUT double buffer operations to avoid updating the
+ * LUT table entries while a frame is being displayed.
+ */
+int rcar_cmm_setup(struct platform_device *pdev,
+		   const struct rcar_cmm_config *config)
+{
+	struct rcar_cmm *rcmm = platform_get_drvdata(pdev);
+
+	/* Disable LUT if no table is provided. */
+	if (!config->lut.table) {
+		if (rcmm->lut.enabled) {
+			rcar_cmm_write(rcmm, CM2_LUT_CTRL, 0);
+			rcmm->lut.enabled = false;
+		}
+
+		return 0;
+	}
+
+	/* Enable LUT and program the new gamma table values. */
+	if (!rcmm->lut.enabled) {
+		rcar_cmm_write(rcmm, CM2_LUT_CTRL, CM2_LUT_CTRL_LUT_EN);
+		rcmm->lut.enabled = true;
+	}
+
+	rcar_cmm_lut_write(rcmm, config->lut.table);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rcar_cmm_setup);
+
+/*
+ * rcar_cmm_enable() - Enable the CMM unit
+ * @pdev: The platform device associated with the CMM instance
+ *
+ * When the output of the corresponding DU channel is routed to the CMM unit,
+ * the unit shall be enabled before the DU channel is started, and remain
+ * enabled until the channel is stopped. The CMM unit shall be disabled with
+ * rcar_cmm_disable().
+ *
+ * Calls to rcar_cmm_enable() and rcar_cmm_disable() are not reference-counted.
+ * It is an error to attempt to enable an already enabled CMM unit, or to
+ * attempt to disable a disabled unit.
+ */
+int rcar_cmm_enable(struct platform_device *pdev)
+{
+	int ret;
+
+	ret = pm_runtime_get_sync(&pdev->dev);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rcar_cmm_enable);
+
+/*
+ * rcar_cmm_disable() - Disable the CMM unit
+ * @pdev: The platform device associated with the CMM instance
+ *
+ * See rcar_cmm_enable() for usage information.
+ *
+ * Disabling the CMM unit disable all the internal processing blocks. The CMM
+ * state shall thus be restored with rcar_cmm_setup() when re-enabling the CMM
+ * unit after the next rcar_cmm_enable() call.
+ */
+void rcar_cmm_disable(struct platform_device *pdev)
+{
+	struct rcar_cmm *rcmm = platform_get_drvdata(pdev);
+
+	rcar_cmm_write(rcmm, CM2_LUT_CTRL, 0);
+	rcmm->lut.enabled = false;
+
+	pm_runtime_put(&pdev->dev);
+}
+EXPORT_SYMBOL_GPL(rcar_cmm_disable);
+
+/*
+ * rcar_cmm_init() - Initialize the CMM unit
+ * @pdev: The platform device associated with the CMM instance
+ *
+ * Return: 0 on success, -EPROBE_DEFER if the CMM is not available yet,
+ *         -ENODEV if the DRM_RCAR_CMM config option is disabled
+ */
+int rcar_cmm_init(struct platform_device *pdev)
+{
+	struct rcar_cmm *rcmm = platform_get_drvdata(pdev);
+
+	if (!rcmm)
+		return -EPROBE_DEFER;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rcar_cmm_init);
+
+static int rcar_cmm_probe(struct platform_device *pdev)
+{
+	struct rcar_cmm *rcmm;
+
+	rcmm = devm_kzalloc(&pdev->dev, sizeof(*rcmm), GFP_KERNEL);
+	if (!rcmm)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, rcmm);
+
+	rcmm->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(rcmm->base))
+		return PTR_ERR(rcmm->base);
+
+	pm_runtime_enable(&pdev->dev);
+
+	return 0;
+}
+
+static int rcar_cmm_remove(struct platform_device *pdev)
+{
+	pm_runtime_disable(&pdev->dev);
+
+	return 0;
+}
+
+static const struct of_device_id rcar_cmm_of_table[] = {
+	{ .compatible = "renesas,rcar-gen3-cmm", },
+	{ .compatible = "renesas,rcar-gen2-cmm", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, rcar_cmm_of_table);
+
+static struct platform_driver rcar_cmm_platform_driver = {
+	.probe		= rcar_cmm_probe,
+	.remove		= rcar_cmm_remove,
+	.driver		= {
+		.name	= "rcar-cmm",
+		.of_match_table = rcar_cmm_of_table,
+	},
+};
+
+module_platform_driver(rcar_cmm_platform_driver);
+
+MODULE_AUTHOR("Jacopo Mondi <jacopo+renesas@jmondi.org>");
+MODULE_DESCRIPTION("Renesas R-Car CMM Driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/gpu/drm/rcar-du/rcar_cmm.h b/drivers/gpu/drm/rcar-du/rcar_cmm.h
new file mode 100644
index 000000000000..b5f7ec6db04a
--- /dev/null
+++ b/drivers/gpu/drm/rcar-du/rcar_cmm.h
@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * rcar_cmm.h -- R-Car Display Unit Color Management Module
+ *
+ * Copyright (C) 2019 Jacopo Mondi <jacopo+renesas@jmondi.org>
+ */
+
+#ifndef __RCAR_CMM_H__
+#define __RCAR_CMM_H__
+
+#define CM2_LUT_SIZE		256
+
+struct drm_color_lut;
+struct platform_device;
+
+/**
+ * struct rcar_cmm_config - CMM configuration
+ *
+ * @lut:	1D-LUT configuration
+ * @lut.table:	1D-LUT table entries. Disable LUT operations when NULL
+ */
+struct rcar_cmm_config {
+	struct {
+		struct drm_color_lut *table;
+	} lut;
+};
+
+#if IS_ENABLED(CONFIG_DRM_RCAR_CMM)
+int rcar_cmm_init(struct platform_device *pdev);
+
+int rcar_cmm_enable(struct platform_device *pdev);
+void rcar_cmm_disable(struct platform_device *pdev);
+
+int rcar_cmm_setup(struct platform_device *pdev,
+		   const struct rcar_cmm_config *config);
+#else
+static inline int rcar_cmm_init(struct platform_device *pdev)
+{
+	return -ENODEV;
+}
+
+static inline int rcar_cmm_enable(struct platform_device *pdev)
+{
+	return 0;
+}
+
+static inline void rcar_cmm_disable(struct platform_device *pdev)
+{
+}
+
+static inline int rcar_cmm_setup(struct platform_device *pdev,
+				 const struct rcar_cmm_config *config)
+{
+	return 0;
+}
+#endif /* IS_ENABLED(CONFIG_DRM_RCAR_CMM) */
+
+#endif /* __RCAR_CMM_H__ */
--
2.23.0

Re: [PATCH v7 3/7] drm: rcar-du: Add support for CMM

[Laurent Pinchart]

Hi Jacopo,

Thank you for the patch.

On Wed, Nov 13, 2019 at 11:05:52AM +0100, Jacopo Mondi wrote:
> Add a driver for the R-Car Display Unit Color Correction Module.
> 
> In most of Gen3 SoCs, each DU output channel is provided with a CMM unit
> to perform image enhancement and color correction.
> 
> Add support for CMM through a driver that supports configuration of
> the 1-dimensional LUT table. More advanced CMM features will be
> implemented on top of this initial one.
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> 
> ---
> v6 -> v7
> - Expand rcar_cmm_setup() function documentation to detail its relationship
>   with rcar_cmm_enable() and their call order precedence.
> 
> - Kconfig update: Make DRM_RCAR_CMM a tristate option and 'imply' it from the
>   RCAR_DU one. This guarantees that if DU is built as a module CMM can only be
>   built as a module as well. At the same time, if DU is built-in, CMM can
>   be built-in only.
> ---
>  drivers/gpu/drm/rcar-du/Kconfig    |   8 ++
>  drivers/gpu/drm/rcar-du/Makefile   |   1 +
>  drivers/gpu/drm/rcar-du/rcar_cmm.c | 217 +++++++++++++++++++++++++++++
>  drivers/gpu/drm/rcar-du/rcar_cmm.h |  58 ++++++++
>  4 files changed, 284 insertions(+)
>  create mode 100644 drivers/gpu/drm/rcar-du/rcar_cmm.c
>  create mode 100644 drivers/gpu/drm/rcar-du/rcar_cmm.h
> 
> diff --git a/drivers/gpu/drm/rcar-du/Kconfig b/drivers/gpu/drm/rcar-du/Kconfig
> index 1529849e217e..6ed7a4f3c44e 100644
> --- a/drivers/gpu/drm/rcar-du/Kconfig
> +++ b/drivers/gpu/drm/rcar-du/Kconfig
> @@ -5,6 +5,7 @@ config DRM_RCAR_DU
>  	depends on ARM || ARM64
>  	depends on ARCH_RENESAS || COMPILE_TEST
>  	imply DRM_RCAR_LVDS
> +	imply DRM_RCAR_CMM

I'll swap those two lines.

>  	select DRM_KMS_HELPER
>  	select DRM_KMS_CMA_HELPER
>  	select DRM_GEM_CMA_HELPER
> @@ -13,6 +14,13 @@ config DRM_RCAR_DU
>  	  Choose this option if you have an R-Car chipset.
>  	  If M is selected the module will be called rcar-du-drm.
> 
> +config DRM_RCAR_CMM
> +	tristate "R-Car DU Color Management Module (CMM) Support"
> +	depends on DRM && OF
> +	depends on DRM_RCAR_DU

I just wanted to point out that this prevents DRM_RCAR_DU=m and
DRM_RCAR_CMM=y, but I don't think that is a useful use case.

> +	help
> +	  Enable support for R-Car Color Management Module (CMM).
> +
>  config DRM_RCAR_DW_HDMI
>  	tristate "R-Car DU Gen3 HDMI Encoder Support"
>  	depends on DRM && OF
> diff --git a/drivers/gpu/drm/rcar-du/Makefile b/drivers/gpu/drm/rcar-du/Makefile
> index 6c2ed9c46467..4d1187ccc3e5 100644
> --- a/drivers/gpu/drm/rcar-du/Makefile
> +++ b/drivers/gpu/drm/rcar-du/Makefile
> @@ -15,6 +15,7 @@ rcar-du-drm-$(CONFIG_DRM_RCAR_LVDS)	+= rcar_du_of.o \
>  rcar-du-drm-$(CONFIG_DRM_RCAR_VSP)	+= rcar_du_vsp.o
>  rcar-du-drm-$(CONFIG_DRM_RCAR_WRITEBACK) += rcar_du_writeback.o
> 
> +obj-$(CONFIG_DRM_RCAR_CMM)		+= rcar_cmm.o
>  obj-$(CONFIG_DRM_RCAR_DU)		+= rcar-du-drm.o
>  obj-$(CONFIG_DRM_RCAR_DW_HDMI)		+= rcar_dw_hdmi.o
>  obj-$(CONFIG_DRM_RCAR_LVDS)		+= rcar_lvds.o
> diff --git a/drivers/gpu/drm/rcar-du/rcar_cmm.c b/drivers/gpu/drm/rcar-du/rcar_cmm.c
> new file mode 100644
> index 000000000000..c578095b09a5
> --- /dev/null
> +++ b/drivers/gpu/drm/rcar-du/rcar_cmm.c
> @@ -0,0 +1,217 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * rcar_cmm.c -- R-Car Display Unit Color Management Module
> + *
> + * Copyright (C) 2019 Jacopo Mondi <jacopo+renesas@jmondi.org>
> + */
> +
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +
> +#include <drm/drm_color_mgmt.h>
> +
> +#include "rcar_cmm.h"
> +
> +#define CM2_LUT_CTRL		0x0000
> +#define CM2_LUT_CTRL_LUT_EN	BIT(0)
> +#define CM2_LUT_TBL_BASE	0x0600
> +#define CM2_LUT_TBL(__i)	(CM2_LUT_TBL_BASE + (__i) * 4)
> +
> +struct rcar_cmm {
> +	void __iomem *base;
> +
> +	/*
> +	 * @lut:		1D-LUT state
> +	 * @lut.enabled:	1D-LUT enabled flag
> +	 */
> +	struct {
> +		bool enabled;
> +	} lut;
> +};
> +
> +static inline int rcar_cmm_read(struct rcar_cmm *rcmm, u32 reg)
> +{
> +	return ioread32(rcmm->base + reg);
> +}
> +
> +static inline void rcar_cmm_write(struct rcar_cmm *rcmm, u32 reg, u32 data)
> +{
> +	iowrite32(data, rcmm->base + reg);
> +}
> +
> +/*
> + * rcar_cmm_lut_write() - Scale the DRM LUT table entries to hardware precision
> + *			  and write to the CMM registers
> + * @rcmm: Pointer to the CMM device
> + * @drm_lut: Pointer to the DRM LUT table
> + */
> +static void rcar_cmm_lut_write(struct rcar_cmm *rcmm,
> +			       const struct drm_color_lut *drm_lut)
> +{
> +	unsigned int i;
> +
> +	for (i = 0; i < CM2_LUT_SIZE; ++i) {
> +		u32 entry = drm_color_lut_extract(drm_lut[i].red, 8) << 16
> +			  | drm_color_lut_extract(drm_lut[i].green, 8) << 8
> +			  | drm_color_lut_extract(drm_lut[i].blue, 8);
> +
> +		rcar_cmm_write(rcmm, CM2_LUT_TBL(i), entry);
> +	}
> +}
> +
> +/*
> + * rcar_cmm_setup() - Configure the CMM unit
> + * @pdev: The platform device associated with the CMM instance
> + * @config: The CMM unit configuration
> + *
> + * Configure the CMM unit with the given configuration. Currently enabling,
> + * disabling and programming of the 1-D LUT unit is supported.
> + *
> + * As rcar_cmm_setup() accesses the CMM registers the unit should be powered
> + * and its functional clock enabled. To guarantee this, before any call to
> + * this function is made, the CMM unit has to be enabled by calling
> + * rcar_cmm_enable() first.
> + *
> + * TODO: Add support for LUT double buffer operations to avoid updating the
> + * LUT table entries while a frame is being displayed.
> + */
> +int rcar_cmm_setup(struct platform_device *pdev,
> +		   const struct rcar_cmm_config *config)
> +{
> +	struct rcar_cmm *rcmm = platform_get_drvdata(pdev);
> +
> +	/* Disable LUT if no table is provided. */
> +	if (!config->lut.table) {
> +		if (rcmm->lut.enabled) {
> +			rcar_cmm_write(rcmm, CM2_LUT_CTRL, 0);
> +			rcmm->lut.enabled = false;
> +		}
> +
> +		return 0;
> +	}
> +
> +	/* Enable LUT and program the new gamma table values. */
> +	if (!rcmm->lut.enabled) {
> +		rcar_cmm_write(rcmm, CM2_LUT_CTRL, CM2_LUT_CTRL_LUT_EN);
> +		rcmm->lut.enabled = true;
> +	}
> +
> +	rcar_cmm_lut_write(rcmm, config->lut.table);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(rcar_cmm_setup);
> +
> +/*
> + * rcar_cmm_enable() - Enable the CMM unit
> + * @pdev: The platform device associated with the CMM instance
> + *
> + * When the output of the corresponding DU channel is routed to the CMM unit,
> + * the unit shall be enabled before the DU channel is started, and remain
> + * enabled until the channel is stopped. The CMM unit shall be disabled with
> + * rcar_cmm_disable().
> + *
> + * Calls to rcar_cmm_enable() and rcar_cmm_disable() are not reference-counted.
> + * It is an error to attempt to enable an already enabled CMM unit, or to
> + * attempt to disable a disabled unit.
> + */
> +int rcar_cmm_enable(struct platform_device *pdev)
> +{
> +	int ret;
> +
> +	ret = pm_runtime_get_sync(&pdev->dev);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(rcar_cmm_enable);
> +
> +/*
> + * rcar_cmm_disable() - Disable the CMM unit
> + * @pdev: The platform device associated with the CMM instance
> + *
> + * See rcar_cmm_enable() for usage information.
> + *
> + * Disabling the CMM unit disable all the internal processing blocks. The CMM
> + * state shall thus be restored with rcar_cmm_setup() when re-enabling the CMM
> + * unit after the next rcar_cmm_enable() call.
> + */
> +void rcar_cmm_disable(struct platform_device *pdev)
> +{
> +	struct rcar_cmm *rcmm = platform_get_drvdata(pdev);
> +
> +	rcar_cmm_write(rcmm, CM2_LUT_CTRL, 0);
> +	rcmm->lut.enabled = false;
> +
> +	pm_runtime_put(&pdev->dev);
> +}
> +EXPORT_SYMBOL_GPL(rcar_cmm_disable);
> +
> +/*
> + * rcar_cmm_init() - Initialize the CMM unit
> + * @pdev: The platform device associated with the CMM instance
> + *
> + * Return: 0 on success, -EPROBE_DEFER if the CMM is not available yet,
> + *         -ENODEV if the DRM_RCAR_CMM config option is disabled
> + */
> +int rcar_cmm_init(struct platform_device *pdev)
> +{
> +	struct rcar_cmm *rcmm = platform_get_drvdata(pdev);
> +
> +	if (!rcmm)
> +		return -EPROBE_DEFER;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(rcar_cmm_init);
> +
> +static int rcar_cmm_probe(struct platform_device *pdev)
> +{
> +	struct rcar_cmm *rcmm;
> +
> +	rcmm = devm_kzalloc(&pdev->dev, sizeof(*rcmm), GFP_KERNEL);
> +	if (!rcmm)
> +		return -ENOMEM;
> +	platform_set_drvdata(pdev, rcmm);
> +
> +	rcmm->base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(rcmm->base))
> +		return PTR_ERR(rcmm->base);
> +
> +	pm_runtime_enable(&pdev->dev);
> +
> +	return 0;
> +}
> +
> +static int rcar_cmm_remove(struct platform_device *pdev)
> +{
> +	pm_runtime_disable(&pdev->dev);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id rcar_cmm_of_table[] = {
> +	{ .compatible = "renesas,rcar-gen3-cmm", },
> +	{ .compatible = "renesas,rcar-gen2-cmm", },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, rcar_cmm_of_table);
> +
> +static struct platform_driver rcar_cmm_platform_driver = {
> +	.probe		= rcar_cmm_probe,
> +	.remove		= rcar_cmm_remove,
> +	.driver		= {
> +		.name	= "rcar-cmm",
> +		.of_match_table = rcar_cmm_of_table,
> +	},
> +};
> +
> +module_platform_driver(rcar_cmm_platform_driver);
> +
> +MODULE_AUTHOR("Jacopo Mondi <jacopo+renesas@jmondi.org>");
> +MODULE_DESCRIPTION("Renesas R-Car CMM Driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/gpu/drm/rcar-du/rcar_cmm.h b/drivers/gpu/drm/rcar-du/rcar_cmm.h
> new file mode 100644
> index 000000000000..b5f7ec6db04a
> --- /dev/null
> +++ b/drivers/gpu/drm/rcar-du/rcar_cmm.h
> @@ -0,0 +1,58 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * rcar_cmm.h -- R-Car Display Unit Color Management Module
> + *
> + * Copyright (C) 2019 Jacopo Mondi <jacopo+renesas@jmondi.org>
> + */
> +
> +#ifndef __RCAR_CMM_H__
> +#define __RCAR_CMM_H__
> +
> +#define CM2_LUT_SIZE		256
> +
> +struct drm_color_lut;
> +struct platform_device;
> +
> +/**
> + * struct rcar_cmm_config - CMM configuration
> + *
> + * @lut:	1D-LUT configuration
> + * @lut.table:	1D-LUT table entries. Disable LUT operations when NULL
> + */
> +struct rcar_cmm_config {
> +	struct {
> +		struct drm_color_lut *table;
> +	} lut;
> +};
> +
> +#if IS_ENABLED(CONFIG_DRM_RCAR_CMM)
> +int rcar_cmm_init(struct platform_device *pdev);
> +
> +int rcar_cmm_enable(struct platform_device *pdev);
> +void rcar_cmm_disable(struct platform_device *pdev);
> +
> +int rcar_cmm_setup(struct platform_device *pdev,
> +		   const struct rcar_cmm_config *config);
> +#else
> +static inline int rcar_cmm_init(struct platform_device *pdev)
> +{
> +	return -ENODEV;
> +}
> +
> +static inline int rcar_cmm_enable(struct platform_device *pdev)
> +{
> +	return 0;
> +}
> +
> +static inline void rcar_cmm_disable(struct platform_device *pdev)
> +{
> +}
> +
> +static inline int rcar_cmm_setup(struct platform_device *pdev,
> +				 const struct rcar_cmm_config *config)
> +{
> +	return 0;
> +}
> +#endif /* IS_ENABLED(CONFIG_DRM_RCAR_CMM) */
> +
> +#endif /* __RCAR_CMM_H__ */

-- 
Regards,

Laurent Pinchart

Re: [PATCH v7 3/7] drm: rcar-du: Add support for CMM

[Geert Uytterhoeven]

Hi Jacopo,

On Wed, Nov 13, 2019 at 11:04 AM Jacopo Mondi <jacopo+renesas@jmondi.org> wrote:
> Add a driver for the R-Car Display Unit Color Correction Module.
> In most of Gen3 SoCs, each DU output channel is provided with a CMM unit
> to perform image enhancement and color correction.
>
> Add support for CMM through a driver that supports configuration of
> the 1-dimensional LUT table. More advanced CMM features will be
> implemented on top of this initial one.
>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>

> --- a/drivers/gpu/drm/rcar-du/Kconfig
> +++ b/drivers/gpu/drm/rcar-du/Kconfig
> @@ -5,6 +5,7 @@ config DRM_RCAR_DU
>         depends on ARM || ARM64
>         depends on ARCH_RENESAS || COMPILE_TEST
>         imply DRM_RCAR_LVDS
> +       imply DRM_RCAR_CMM
>         select DRM_KMS_HELPER
>         select DRM_KMS_CMA_HELPER
>         select DRM_GEM_CMA_HELPER
> @@ -13,6 +14,13 @@ config DRM_RCAR_DU
>           Choose this option if you have an R-Car chipset.
>           If M is selected the module will be called rcar-du-drm.
>
> +config DRM_RCAR_CMM
> +       tristate "R-Car DU Color Management Module (CMM) Support"
> +       depends on DRM && OF
> +       depends on DRM_RCAR_DU

DRM_RCAR_DU already depends on DRM && OF, so the line above
can be removed.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v7 3/7] drm: rcar-du: Add support for CMM

[Laurent Pinchart]

Hi Geert,

On Thu, Nov 28, 2019 at 08:56:14AM +0100, Geert Uytterhoeven wrote:
> On Wed, Nov 13, 2019 at 11:04 AM Jacopo Mondi <jacopo+renesas@jmondi.org> wrote:
> > Add a driver for the R-Car Display Unit Color Correction Module.
> > In most of Gen3 SoCs, each DU output channel is provided with a CMM unit
> > to perform image enhancement and color correction.
> >
> > Add support for CMM through a driver that supports configuration of
> > the 1-dimensional LUT table. More advanced CMM features will be
> > implemented on top of this initial one.
> >
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> 
> > --- a/drivers/gpu/drm/rcar-du/Kconfig
> > +++ b/drivers/gpu/drm/rcar-du/Kconfig
> > @@ -5,6 +5,7 @@ config DRM_RCAR_DU
> >         depends on ARM || ARM64
> >         depends on ARCH_RENESAS || COMPILE_TEST
> >         imply DRM_RCAR_LVDS
> > +       imply DRM_RCAR_CMM
> >         select DRM_KMS_HELPER
> >         select DRM_KMS_CMA_HELPER
> >         select DRM_GEM_CMA_HELPER
> > @@ -13,6 +14,13 @@ config DRM_RCAR_DU
> >           Choose this option if you have an R-Car chipset.
> >           If M is selected the module will be called rcar-du-drm.
> >
> > +config DRM_RCAR_CMM
> > +       tristate "R-Car DU Color Management Module (CMM) Support"
> > +       depends on DRM && OF
> > +       depends on DRM_RCAR_DU
> 
> DRM_RCAR_DU already depends on DRM && OF, so the line above
> can be removed.

I've sent a pull request already. Can we address this on top ? Or is it
worth a separate patch, should we wait until we have to touch this and
then fix it in a "while at it" fashion ?

-- 
Regards,

Laurent Pinchart

Re: [PATCH v7 3/7] drm: rcar-du: Add support for CMM

[Geert Uytterhoeven]

Hi Laurent,

On Thu, Nov 28, 2019 at 9:09 AM Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
> On Thu, Nov 28, 2019 at 08:56:14AM +0100, Geert Uytterhoeven wrote:
> > On Wed, Nov 13, 2019 at 11:04 AM Jacopo Mondi <jacopo+renesas@jmondi.org> wrote:
> > > Add a driver for the R-Car Display Unit Color Correction Module.
> > > In most of Gen3 SoCs, each DU output channel is provided with a CMM unit
> > > to perform image enhancement and color correction.
> > >
> > > Add support for CMM through a driver that supports configuration of
> > > the 1-dimensional LUT table. More advanced CMM features will be
> > > implemented on top of this initial one.
> > >
> > > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> > > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> >
> > > --- a/drivers/gpu/drm/rcar-du/Kconfig
> > > +++ b/drivers/gpu/drm/rcar-du/Kconfig
> > > @@ -5,6 +5,7 @@ config DRM_RCAR_DU
> > >         depends on ARM || ARM64
> > >         depends on ARCH_RENESAS || COMPILE_TEST
> > >         imply DRM_RCAR_LVDS
> > > +       imply DRM_RCAR_CMM
> > >         select DRM_KMS_HELPER
> > >         select DRM_KMS_CMA_HELPER
> > >         select DRM_GEM_CMA_HELPER
> > > @@ -13,6 +14,13 @@ config DRM_RCAR_DU
> > >           Choose this option if you have an R-Car chipset.
> > >           If M is selected the module will be called rcar-du-drm.
> > >
> > > +config DRM_RCAR_CMM
> > > +       tristate "R-Car DU Color Management Module (CMM) Support"
> > > +       depends on DRM && OF
> > > +       depends on DRM_RCAR_DU
> >
> > DRM_RCAR_DU already depends on DRM && OF, so the line above
> > can be removed.
>
> I've sent a pull request already. Can we address this on top ? Or is it
> worth a separate patch, should we wait until we have to touch this and
> then fix it in a "while at it" fashion ?

Sure. "while at it" is fine for me.  It's not blocker.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

[PATCH v7 4/7] drm: rcar-du: kms: Initialize CMM instances

[Jacopo Mondi]

Implement device tree parsing to collect the available CMM instances
described by the 'renesas,cmms' property. Associate CMMs with CRTCs and
store a mask of active CMMs in the DU group for later enablement.

Enforce the probe and suspend/resume ordering of DU and CMM by creating
a stateless device link between the two.

Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
---
 drivers/gpu/drm/rcar-du/rcar_du_crtc.c  |  6 ++
 drivers/gpu/drm/rcar-du/rcar_du_crtc.h  |  2 +
 drivers/gpu/drm/rcar-du/rcar_du_drv.h   |  2 +
 drivers/gpu/drm/rcar-du/rcar_du_group.h |  2 +
 drivers/gpu/drm/rcar-du/rcar_du_kms.c   | 76 +++++++++++++++++++++++++
 5 files changed, 88 insertions(+)

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
index 2da46e3dc4ae..23f1d6cc1719 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
@@ -1194,6 +1194,12 @@ int rcar_du_crtc_create(struct rcar_du_group *rgrp, unsigned int swindex,
 	if (ret < 0)
 		return ret;
 
+	/* CMM might be disabled for this CRTC. */
+	if (rcdu->cmms[swindex]) {
+		rcrtc->cmm = rcdu->cmms[swindex];
+		rgrp->cmms_mask |= BIT(hwindex % 2);
+	}
+
 	drm_crtc_helper_add(crtc, &crtc_helper_funcs);
 
 	/* Start with vertical blanking interrupt reporting disabled. */
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.h b/drivers/gpu/drm/rcar-du/rcar_du_crtc.h
index 3b7fc668996f..5f2940c42225 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.h
+++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.h
@@ -39,6 +39,7 @@ struct rcar_du_vsp;
  * @vblank_wait: wait queue used to signal vertical blanking
  * @vblank_count: number of vertical blanking interrupts to wait for
  * @group: CRTC group this CRTC belongs to
+ * @cmm: CMM associated with this CRTC
  * @vsp: VSP feeding video to this CRTC
  * @vsp_pipe: index of the VSP pipeline feeding video to this CRTC
  * @writeback: the writeback connector
@@ -64,6 +65,7 @@ struct rcar_du_crtc {
 	unsigned int vblank_count;
 
 	struct rcar_du_group *group;
+	struct platform_device *cmm;
 	struct rcar_du_vsp *vsp;
 	unsigned int vsp_pipe;
 
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.h b/drivers/gpu/drm/rcar-du/rcar_du_drv.h
index 1327cd0df90a..61504c54e2ec 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_drv.h
+++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.h
@@ -13,6 +13,7 @@
 #include <linux/kernel.h>
 #include <linux/wait.h>
 
+#include "rcar_cmm.h"
 #include "rcar_du_crtc.h"
 #include "rcar_du_group.h"
 #include "rcar_du_vsp.h"
@@ -85,6 +86,7 @@ struct rcar_du_device {
 	struct rcar_du_encoder *encoders[RCAR_DU_OUTPUT_MAX];
 
 	struct rcar_du_group groups[RCAR_DU_MAX_GROUPS];
+	struct platform_device *cmms[RCAR_DU_MAX_CRTCS];
 	struct rcar_du_vsp vsps[RCAR_DU_MAX_VSPS];
 
 	struct {
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_group.h b/drivers/gpu/drm/rcar-du/rcar_du_group.h
index 87950c1f6a52..e9906609c635 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_group.h
+++ b/drivers/gpu/drm/rcar-du/rcar_du_group.h
@@ -22,6 +22,7 @@ struct rcar_du_device;
  * @mmio_offset: registers offset in the device memory map
  * @index: group index
  * @channels_mask: bitmask of populated DU channels in this group
+ * @cmms_mask: bitmask of available CMMs in this group
  * @num_crtcs: number of CRTCs in this group (1 or 2)
  * @use_count: number of users of the group (rcar_du_group_(get|put))
  * @used_crtcs: number of CRTCs currently in use
@@ -37,6 +38,7 @@ struct rcar_du_group {
 	unsigned int index;
 
 	unsigned int channels_mask;
+	unsigned int cmms_mask;
 	unsigned int num_crtcs;
 	unsigned int use_count;
 	unsigned int used_crtcs;
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
index 2dc9caee8767..7c9fb5860e54 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
@@ -17,7 +17,9 @@
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_vblank.h>
 
+#include <linux/device.h>
 #include <linux/of_graph.h>
+#include <linux/of_platform.h>
 #include <linux/wait.h>
 
 #include "rcar_du_crtc.h"
@@ -614,6 +616,75 @@ static int rcar_du_vsps_init(struct rcar_du_device *rcdu)
 	return ret;
 }
 
+static int rcar_du_cmm_init(struct rcar_du_device *rcdu)
+{
+	const struct device_node *np = rcdu->dev->of_node;
+	unsigned int i;
+	int cells;
+
+	cells = of_property_count_u32_elems(np, "renesas,cmms");
+	if (cells == -EINVAL)
+		return 0;
+
+	if (cells > rcdu->num_crtcs) {
+		dev_err(rcdu->dev,
+			"Invalid number of entries in 'renesas,cmms'\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < cells; ++i) {
+		struct platform_device *pdev;
+		struct device_link *link;
+		struct device_node *cmm;
+		int ret;
+
+		cmm = of_parse_phandle(np, "renesas,cmms", i);
+		if (IS_ERR(cmm)) {
+			dev_err(rcdu->dev,
+				"Failed to parse 'renesas,cmms' property\n");
+			return PTR_ERR(cmm);
+		}
+
+		if (!of_device_is_available(cmm)) {
+			/* It's fine to have a phandle to a non-enabled CMM. */
+			of_node_put(cmm);
+			continue;
+		}
+
+		pdev = of_find_device_by_node(cmm);
+		if (IS_ERR(pdev)) {
+			dev_err(rcdu->dev, "No device found for CMM%u\n", i);
+			of_node_put(cmm);
+			return PTR_ERR(pdev);
+		}
+
+		of_node_put(cmm);
+
+		/*
+		 * -ENODEV is used to report that the CMM config option is
+		 * disabled: return 0 and let the DU continue probing.
+		 */
+		ret = rcar_cmm_init(pdev);
+		if (ret)
+			return ret == -ENODEV ? 0 : ret;
+
+		/*
+		 * Enforce suspend/resume ordering by making the CMM a provider
+		 * of the DU: CMM is suspended after and resumed before the DU.
+		 */
+		link = device_link_add(rcdu->dev, &pdev->dev, DL_FLAG_STATELESS);
+		if (!link) {
+			dev_err(rcdu->dev,
+				"Failed to create device link to CMM%u\n", i);
+			return -EINVAL;
+		}
+
+		rcdu->cmms[i] = pdev;
+	}
+
+	return 0;
+}
+
 int rcar_du_modeset_init(struct rcar_du_device *rcdu)
 {
 	static const unsigned int mmio_offsets[] = {
@@ -704,6 +775,11 @@ int rcar_du_modeset_init(struct rcar_du_device *rcdu)
 			return ret;
 	}
 
+	/* Initialize the Color Management Modules. */
+	ret = rcar_du_cmm_init(rcdu);
+	if (ret)
+		return ret;
+
 	/* Create the CRTCs. */
 	for (swindex = 0, hwindex = 0; swindex < rcdu->num_crtcs; ++hwindex) {
 		struct rcar_du_group *rgrp;
-- 
2.23.0

[PATCH v7 5/7] drm: rcar-du: crtc: Control CMM operations

[Jacopo Mondi]

Implement CMM handling in the crtc begin and enable atomic callbacks,
and enable CMM unit through the Display Extensional Functions
register at group setup time.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>

---
v6 -> v7
- Drop check for CMM in rcar_du_cmm_check as if the gamma_table property is
  available, a CMM unit for this CRTC was registered
- Add TODO note to investigate how the activation order of CMM and CRTC
  impact on the first displayed fram
---
---
 drivers/gpu/drm/rcar-du/rcar_du_crtc.c  | 61 +++++++++++++++++++++++++
 drivers/gpu/drm/rcar-du/rcar_du_group.c | 10 ++++
 drivers/gpu/drm/rcar-du/rcar_du_regs.h  |  5 ++
 3 files changed, 76 insertions(+)

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
index 23f1d6cc1719..3f0f16946f42 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
@@ -21,6 +21,7 @@
 #include <drm/drm_plane_helper.h>
 #include <drm/drm_vblank.h>
 
+#include "rcar_cmm.h"
 #include "rcar_du_crtc.h"
 #include "rcar_du_drv.h"
 #include "rcar_du_encoder.h"
@@ -474,6 +475,45 @@ static void rcar_du_crtc_wait_page_flip(struct rcar_du_crtc *rcrtc)
 	rcar_du_crtc_finish_page_flip(rcrtc);
 }
 
+/* -----------------------------------------------------------------------------
+ * Color Management Module (CMM)
+ */
+
+static int rcar_du_cmm_check(struct drm_crtc *crtc,
+			     struct drm_crtc_state *state)
+{
+	struct drm_property_blob *drm_lut = state->gamma_lut;
+	struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc);
+	struct device *dev = rcrtc->dev->dev;
+
+	if (!drm_lut)
+		return 0;
+
+	/* We only accept fully populated LUT tables. */
+	if (drm_color_lut_size(drm_lut) != CM2_LUT_SIZE) {
+		dev_err(dev, "invalid gamma lut size: %lu bytes\n",
+			drm_lut->length);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void rcar_du_cmm_setup(struct drm_crtc *crtc)
+{
+	struct drm_property_blob *drm_lut = crtc->state->gamma_lut;
+	struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc);
+	struct rcar_cmm_config cmm_config = {};
+
+	if (!rcrtc->cmm)
+		return;
+
+	if (drm_lut)
+		cmm_config.lut.table = (struct drm_color_lut *)drm_lut->data;
+
+	rcar_cmm_setup(rcrtc->cmm, &cmm_config);
+}
+
 /* -----------------------------------------------------------------------------
  * Start/Stop and Suspend/Resume
  */
@@ -619,6 +659,9 @@ static void rcar_du_crtc_stop(struct rcar_du_crtc *rcrtc)
 	if (rcar_du_has(rcrtc->dev, RCAR_DU_FEATURE_VSP1_SOURCE))
 		rcar_du_vsp_disable(rcrtc);
 
+	if (rcrtc->cmm)
+		rcar_cmm_disable(rcrtc->cmm);
+
 	/*
 	 * Select switch sync mode. This stops display operation and configures
 	 * the HSYNC and VSYNC signals as inputs.
@@ -642,6 +685,11 @@ static int rcar_du_crtc_atomic_check(struct drm_crtc *crtc,
 {
 	struct rcar_du_crtc_state *rstate = to_rcar_crtc_state(state);
 	struct drm_encoder *encoder;
+	int ret;
+
+	ret = rcar_du_cmm_check(crtc, state);
+	if (ret)
+		return ret;
 
 	/* Store the routes from the CRTC output to the DU outputs. */
 	rstate->outputs = 0;
@@ -667,6 +715,8 @@ static void rcar_du_crtc_atomic_enable(struct drm_crtc *crtc,
 	struct rcar_du_crtc_state *rstate = to_rcar_crtc_state(crtc->state);
 	struct rcar_du_device *rcdu = rcrtc->dev;
 
+	if (rcrtc->cmm)
+		rcar_cmm_enable(rcrtc->cmm);
 	rcar_du_crtc_get(rcrtc);
 
 	/*
@@ -686,6 +736,13 @@ static void rcar_du_crtc_atomic_enable(struct drm_crtc *crtc,
 	}
 
 	rcar_du_crtc_start(rcrtc);
+
+	/*
+	 * TODO: The chip manual indicates that CMM tables should be written
+	 * after the DU channel has been activated. Investigate the impact
+	 * of this restriction on the first displayed frame.
+	 */
+	rcar_du_cmm_setup(crtc);
 }
 
 static void rcar_du_crtc_atomic_disable(struct drm_crtc *crtc,
@@ -739,6 +796,10 @@ static void rcar_du_crtc_atomic_begin(struct drm_crtc *crtc,
 	 */
 	rcar_du_crtc_get(rcrtc);
 
+	/* If the active state changed, we let .atomic_enable handle CMM. */
+	if (crtc->state->color_mgmt_changed && !crtc->state->active_changed)
+		rcar_du_cmm_setup(crtc);
+
 	if (rcar_du_has(rcrtc->dev, RCAR_DU_FEATURE_VSP1_SOURCE))
 		rcar_du_vsp_atomic_begin(rcrtc);
 }
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_group.c b/drivers/gpu/drm/rcar-du/rcar_du_group.c
index 9eee47969e77..88a783ceb3e9 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_group.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_group.c
@@ -135,6 +135,7 @@ static void rcar_du_group_setup_didsr(struct rcar_du_group *rgrp)
 static void rcar_du_group_setup(struct rcar_du_group *rgrp)
 {
 	struct rcar_du_device *rcdu = rgrp->dev;
+	u32 defr7 = DEFR7_CODE;
 
 	/* Enable extended features */
 	rcar_du_group_write(rgrp, DEFR, DEFR_CODE | DEFR_DEFE);
@@ -147,6 +148,15 @@ static void rcar_du_group_setup(struct rcar_du_group *rgrp)
 
 	rcar_du_group_setup_pins(rgrp);
 
+	/*
+	 * TODO: Handle routing of the DU output to CMM dynamically, as we
+	 * should bypass CMM completely when no color management feature is
+	 * used.
+	 */
+	defr7 |= (rgrp->cmms_mask & BIT(1) ? DEFR7_CMME1 : 0) |
+		 (rgrp->cmms_mask & BIT(0) ? DEFR7_CMME0 : 0);
+	rcar_du_group_write(rgrp, DEFR7, defr7);
+
 	if (rcdu->info->gen >= 2) {
 		rcar_du_group_setup_defr8(rgrp);
 		rcar_du_group_setup_didsr(rgrp);
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_regs.h b/drivers/gpu/drm/rcar-du/rcar_du_regs.h
index bc87f080b170..fb9964949368 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_regs.h
+++ b/drivers/gpu/drm/rcar-du/rcar_du_regs.h
@@ -197,6 +197,11 @@
 #define DEFR6_MLOS1		(1 << 2)
 #define DEFR6_DEFAULT		(DEFR6_CODE | DEFR6_TCNE1)
 
+#define DEFR7			0x000ec
+#define DEFR7_CODE		(0x7779 << 16)
+#define DEFR7_CMME1		BIT(6)
+#define DEFR7_CMME0		BIT(4)
+
 /* -----------------------------------------------------------------------------
  * R8A7790-only Control Registers
  */
-- 
2.23.0

[PATCH v7 6/7] drm: rcar-du: crtc: Register GAMMA_LUT properties

[Jacopo Mondi]

Enable the GAMMA_LUT KMS property using the framework helpers to
register the property and set the associated gamma table maximum size.

Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
---
 drivers/gpu/drm/rcar-du/rcar_du_crtc.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
index 3f0f16946f42..e12ce9c8923b 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
@@ -1136,6 +1136,7 @@ static const struct drm_crtc_funcs crtc_funcs_gen3 = {
 	.set_crc_source = rcar_du_crtc_set_crc_source,
 	.verify_crc_source = rcar_du_crtc_verify_crc_source,
 	.get_crc_sources = rcar_du_crtc_get_crc_sources,
+	.gamma_set = drm_atomic_helper_legacy_gamma_set,
 };
 
 /* -----------------------------------------------------------------------------
@@ -1259,6 +1260,9 @@ int rcar_du_crtc_create(struct rcar_du_group *rgrp, unsigned int swindex,
 	if (rcdu->cmms[swindex]) {
 		rcrtc->cmm = rcdu->cmms[swindex];
 		rgrp->cmms_mask |= BIT(hwindex % 2);
+
+		drm_mode_crtc_set_gamma_size(crtc, CM2_LUT_SIZE);
+		drm_crtc_enable_color_mgmt(crtc, 0, false, CM2_LUT_SIZE);
 	}
 
 	drm_crtc_helper_add(crtc, &crtc_helper_funcs);
-- 
2.23.0

[PATCH v7 7/7] drm: rcar-du: kms: Expand comment in vsps parsing routine

[Jacopo Mondi]

Expand comment in the 'vsps' parsing routine to specify the LIF
channel index defaults to 0 in case the second cell of the property
is not specified to remain compatible with older DT bindings.

Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
---
 drivers/gpu/drm/rcar-du/rcar_du_kms.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
index 7c9fb5860e54..186422ac552b 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
@@ -587,7 +587,11 @@ static int rcar_du_vsps_init(struct rcar_du_device *rcdu)
 
 		vsps[j].crtcs_mask |= BIT(i);
 
-		/* Store the VSP pointer and pipe index in the CRTC. */
+		/*
+		 * Store the VSP pointer and pipe index in the CRTC. If the
+		 * second cell of the 'vsps' specifier isn't present, default
+		 * to 0 to remain compatible with older DT bindings.
+		 */
 		rcdu->crtcs[i].vsp = &rcdu->vsps[j];
 		rcdu->crtcs[i].vsp_pipe = cells >= 1 ? args.args[0] : 0;
 	}
-- 
2.23.0