drm: rcar-du: kms: Initialize CMM instances

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>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
index 2da46e3..23f1d6c 100644 (file)
--- 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 3b7fc66..5f2940c 100644 (file)
--- 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 1327cd0..61504c5 100644 (file)
--- 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 87950c1..e990660 100644 (file)
--- 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 0d59f39..186422a 100644 (file)
--- 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"
@@ -618,6 +620,75 @@ error:
        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[] = {
@@ -708,6 +779,11 @@ 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;