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

From: Jacopo Mondi
Date: Wed Nov 13 2019 - 05:04:29 EST


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@xxxxxxxxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
---
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