component: Make into an aggregate bus

This series is from discussion we had on reordering the device lists for
drm shutdown paths[1]. I've introduced an 'aggregate' bus that we put
the aggregate device onto and then we probe the aggregate device once
all the components are probed and call component_add(). The probe/remove
hooks are where the bind/unbind calls go, and then a shutdown hook is
added that can be used to shutdown the drm display pipeline at the right
time.

This works for me on my sc7180 board. I no longer get a warning from i2c
at shutdown that we're trying to make an i2c transaction after the i2c
bus has been shutdown. There's more work to do on the msm drm driver to
extract component device resources like clks, regulators, etc. out of
the component bind function into the driver probe but I wanted to move
everything over now in other component drivers before tackling that
problem.

Tested-by tags would be appreciated, and Acked-by/Reviewed-by tags too.

Changes since v3 (https://lore.kernel.org/r/20211026000044.885195-1-swboyd@chromium.org):
 - Picked up tags
 - Rebased to v5.16-rc2
 - Updated component.c for a few new patches there
 - Dropped a conversion patch
 - Added a conversion patch

Changes since v2 (https://lore.kernel.org/r/20211006193819.2654854-1-swboyd@chromium.org):
 - Picked up acks
 - Fixed build warnings/errors
 - Reworked patch series to rename 'master' in a different patch

Changes since v1 (https://lore.kernel.org/r/20210520002519.3538432-1-swboyd@chromium.org):
 - Use devlink to connect components to the aggregate device
 - Don't set the registering device as a parent of the aggregate device
 - New patch for bind_component/unbind_component ops that takes the
   aggregate device
 - Convert all drivers in the tree to use the aggregate driver approach
 - Allow one aggregate driver to be used for multiple aggregate devices

[1] https://lore.kernel.org/r/20210508074118.1621729-1-swboyd@chromium.org

130 more lines

Use an aggregate driver instead of component ops so that we can get
proper driver probe ordering of the aggregate device with respect to all
the component devices that make up the aggregate device.

Cc: <redacted>
Cc: <redacted>
Cc: Daniel Vetter <redacted>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Rob Clark <redacted>
Cc: Russell King <redacted>
Cc: Saravana Kannan <redacted>
Signed-off-by: Stephen Boyd <redacted>
---
 drivers/video/fbdev/omap2/omapfb/dss/dss.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/video/fbdev/omap2/omapfb/dss/dss.c b/drivers/video/fbdev/omap2/omapfb/dss/dss.c
index a6b1c1598040..f12663c39ceb 100644
--- a/drivers/video/fbdev/omap2/omapfb/dss/dss.c
+++ b/drivers/video/fbdev/omap2/omapfb/dss/dss.c

@@ -1067,8 +1067,9 @@ static int dss_video_pll_probe(struct platform_device *pdev)
 }
 
 /* DSS HW IP initialisation */
-static int dss_bind(struct device *dev)
+static int dss_bind(struct aggregate_device *adev)
 {
+	struct device *dev = adev->parent;
 	struct platform_device *pdev = to_platform_device(dev);
 	struct resource *dss_mem;
 	u32 rev;

@@ -1167,8 +1168,9 @@ static int dss_bind(struct device *dev)
 	return r;
 }
 
-static void dss_unbind(struct device *dev)
+static void dss_unbind(struct aggregate_device *adev)
 {
+	struct device *dev = adev->parent;
 	struct platform_device *pdev = to_platform_device(dev);
 
 	dss_initialized = false;

@@ -1188,9 +1190,13 @@ static void dss_unbind(struct device *dev)
 	dss_put_clocks();
 }
 
-static const struct component_master_ops dss_component_ops = {
-	.bind = dss_bind,
-	.unbind = dss_unbind,
+static struct aggregate_driver dss_aggregate_driver = {
+	.probe = dss_bind,
+	.remove = dss_unbind,
+	.driver = {
+		.name = "dss_fbdev",
+		.owner = THIS_MODULE,
+	},
 };
 
 static int dss_component_compare(struct device *dev, void *data)

@@ -1225,7 +1231,7 @@ static int dss_probe(struct platform_device *pdev)
 	/* add all the child devices as components */
 	device_for_each_child(&pdev->dev, &match, dss_add_child_component);
 
-	r = component_master_add_with_match(&pdev->dev, &dss_component_ops, match);
+	r = component_aggregate_register(&pdev->dev, &dss_aggregate_driver, match);
 	if (r)
 		return r;
 

@@ -1234,7 +1240,7 @@ static int dss_probe(struct platform_device *pdev)
 
 static int dss_remove(struct platform_device *pdev)
 {
-	component_master_del(&pdev->dev, &dss_component_ops);
+	component_aggregate_unregister(&pdev->dev, &dss_aggregate_driver);
 	return 0;
 }
 

-- 
https://chromeos.dev

On Thu, Dec 2, 2021 at 11:27 PM Stephen Boyd [off-list ref] wrote:

  drm/mcde: Migrate to aggregate driver

This also works fine after the patch series.
Tested-by: Linus Walleij <redacted>

Yours,
Linus Walleij

On Thu, Dec 02, 2021 at 02:26:58PM -0800, Stephen Boyd wrote:

This series is from discussion we had on reordering the device lists for
drm shutdown paths[1]. I've introduced an 'aggregate' bus that we put
the aggregate device onto and then we probe the aggregate device once
all the components are probed and call component_add(). The probe/remove
hooks are where the bind/unbind calls go, and then a shutdown hook is
added that can be used to shutdown the drm display pipeline at the right
time.

This works for me on my sc7180 board. I no longer get a warning from i2c
at shutdown that we're trying to make an i2c transaction after the i2c
bus has been shutdown. There's more work to do on the msm drm driver to
extract component device resources like clks, regulators, etc. out of
the component bind function into the driver probe but I wanted to move
everything over now in other component drivers before tackling that
problem.

Tested-by tags would be appreciated, and Acked-by/Reviewed-by tags too.

Thanks for pushing this forward. Unfortunately I'm completely burried and
it's just not improving, so merge plan:

- please get Greg KH to ack the bus/driver core stuff

- please get one of the drm-misc committers we have from Google's Chromeos
  team (there should be a few by now) to review&push this.

Otherwise I fear this might get stuck and I'd really like to avoid that.

Cheers, Daniel

Changes since v3 (https://lore.kernel.org/r/20211026000044.885195-1-swboyd@chromium.org):
 - Picked up tags
 - Rebased to v5.16-rc2
 - Updated component.c for a few new patches there
 - Dropped a conversion patch
 - Added a conversion patch

Changes since v2 (https://lore.kernel.org/r/20211006193819.2654854-1-swboyd@chromium.org):
 - Picked up acks
 - Fixed build warnings/errors
 - Reworked patch series to rename 'master' in a different patch

Changes since v1 (https://lore.kernel.org/r/20210520002519.3538432-1-swboyd@chromium.org):
 - Use devlink to connect components to the aggregate device
 - Don't set the registering device as a parent of the aggregate device
 - New patch for bind_component/unbind_component ops that takes the
   aggregate device
 - Convert all drivers in the tree to use the aggregate driver approach
 - Allow one aggregate driver to be used for multiple aggregate devices

[1] https://lore.kernel.org/r/20210508074118.1621729-1-swboyd@chromium.org


Stephen Boyd (34):
  component: Introduce struct aggregate_device
  component: Remove most references to 'master'
  component: Introduce the aggregate bus_type
  component: Move struct aggregate_device out to header file
  component: Add {bind,unbind}_component() ops that take aggregate
    device
  drm/of: Add a drm_of_aggregate_probe() API
  drm/msm: Migrate to aggregate driver
  drm/komeda: Migrate to aggregate driver
  drm/arm/hdlcd: Migrate to aggregate driver
  drm/malidp: Migrate to aggregate driver
  drm/armada: Migrate to aggregate driver
  drm/etnaviv: Migrate to aggregate driver
  drm/kirin: Migrate to aggregate driver
  drm/exynos: Migrate to aggregate driver

113 more quoted lines

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Quoting Daniel Vetter (2021-12-07 10:22:15)

On Thu, Dec 02, 2021 at 02:26:58PM -0800, Stephen Boyd wrote:

quoted

This series is from discussion we had on reordering the device lists for
drm shutdown paths[1]. I've introduced an 'aggregate' bus that we put
the aggregate device onto and then we probe the aggregate device once
all the components are probed and call component_add(). The probe/remove
hooks are where the bind/unbind calls go, and then a shutdown hook is
added that can be used to shutdown the drm display pipeline at the right
time.

This works for me on my sc7180 board. I no longer get a warning from i2c
at shutdown that we're trying to make an i2c transaction after the i2c
bus has been shutdown. There's more work to do on the msm drm driver to
extract component device resources like clks, regulators, etc. out of
the component bind function into the driver probe but I wanted to move
everything over now in other component drivers before tackling that
problem.

Tested-by tags would be appreciated, and Acked-by/Reviewed-by tags too.

Thanks for pushing this forward. Unfortunately I'm completely burried and
it's just not improving, so merge plan:

- please get Greg KH to ack the bus/driver core stuff

- please get one of the drm-misc committers we have from Google's Chromeos
  team (there should be a few by now) to review&push this.

Sounds like a plan. Thanks!

Otherwise I fear this might get stuck and I'd really like to avoid that.