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Message-ID: <20240627071904.4017160-1-wenst@chromium.org>
Date: Thu, 27 Jun 2024 15:19:03 +0800
From: Chen-Yu Tsai <wenst@...omium.org>
To: Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
Maxime Ripard <mripard@...nel.org>,
Thomas Zimmermann <tzimmermann@...e.de>,
David Airlie <airlied@...il.com>,
Daniel Vetter <daniel@...ll.ch>
Cc: Chen-Yu Tsai <wenst@...omium.org>,
dri-devel@...ts.freedesktop.org,
linux-kernel@...r.kernel.org,
Luca Ceresoli <luca.ceresoli@...tlin.com>
Subject: [PATCH v2] drm/mipi-dsi: Add OF notifier handler
Add OF notifier handler needed for creating/destroying MIPI DSI devices
according to dynamic runtime changes in the DT live tree. This code is
enabled when CONFIG_OF_DYNAMIC is selected.
This is based on existing code for I2C and SPI subsystems.
Signed-off-by: Chen-Yu Tsai <wenst@...omium.org>
---
Changes since v1:
- Added stub mipi_dsi_of_notifier in CONFIG_OF=n section for compilation
drivers/gpu/drm/drm_mipi_dsi.c | 68 +++++++++++++++++++++++++++++++++-
1 file changed, 67 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
index a471c46f5ca6..35d6ed1fb587 100644
--- a/drivers/gpu/drm/drm_mipi_dsi.c
+++ b/drivers/gpu/drm/drm_mipi_dsi.c
@@ -118,6 +118,7 @@ static void mipi_dsi_dev_release(struct device *dev)
{
struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
+ of_node_clear_flag(dev->of_node, OF_POPULATED);
of_node_put(dev->of_node);
kfree(dsi);
}
@@ -158,6 +159,7 @@ static struct mipi_dsi_device *
of_mipi_dsi_device_add(struct mipi_dsi_host *host, struct device_node *node)
{
struct mipi_dsi_device_info info = { };
+ struct mipi_dsi_device *device;
int ret;
u32 reg;
@@ -175,10 +177,72 @@ of_mipi_dsi_device_add(struct mipi_dsi_host *host, struct device_node *node)
info.channel = reg;
info.node = of_node_get(node);
+ of_node_set_flag(node, OF_POPULATED);
- return mipi_dsi_device_register_full(host, &info);
+ device = mipi_dsi_device_register_full(host, &info);
+ if (IS_ERR(device))
+ of_node_clear_flag(node, OF_POPULATED);
+
+ return device;
}
+
+#if IS_ENABLED(CONFIG_OF_DYNAMIC)
+static int of_mipi_dsi_notify(struct notifier_block *nb, unsigned long action, void *arg)
+{
+ struct of_reconfig_data *rd = arg;
+ struct mipi_dsi_host *host;
+ struct mipi_dsi_device *device;
+
+ switch (of_reconfig_get_state_change(action, rd)) {
+ case OF_RECONFIG_CHANGE_ADD:
+ host = of_find_mipi_dsi_host_by_node(rd->dn->parent);
+ if (!host)
+ return NOTIFY_OK; /* not for us */
+
+ if (of_node_test_and_set_flag(rd->dn, OF_POPULATED))
+ return NOTIFY_OK;
+
+ /*
+ * Clear the flag before adding the device so that fw_devlink
+ * doesn't skip adding consumers to this device.
+ */
+ rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
+ device = of_mipi_dsi_device_add(host, rd->dn);
+ if (IS_ERR(device)) {
+ dev_err(host->dev, "failed to create device for '%pOF'\n", rd->dn);
+ of_node_clear_flag(rd->dn, OF_POPULATED);
+ return notifier_from_errno(PTR_ERR(device));
+ }
+ break;
+ case OF_RECONFIG_CHANGE_REMOVE:
+ /* already depopulated? */
+ if (!of_node_check_flag(rd->dn, OF_POPULATED))
+ return NOTIFY_OK;
+
+ /* find our device by node */
+ device = of_find_mipi_dsi_device_by_node(rd->dn);
+ if (!device)
+ return NOTIFY_OK; /* no? not meant for us */
+
+ /* unregister takes one ref away */
+ mipi_dsi_device_unregister(device);
+
+ /* and put the reference of the find */
+ put_device(&device->dev);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block mipi_dsi_of_notifier = {
+ .notifier_call = of_mipi_dsi_notify,
+};
+#else
+static struct notifier_block mipi_dsi_of_notifier __always_unused;
+#endif
#else
+static struct notifier_block mipi_dsi_of_notifier __always_unused;
static struct mipi_dsi_device *
of_mipi_dsi_device_add(struct mipi_dsi_host *host, struct device_node *node)
{
@@ -1703,6 +1767,8 @@ EXPORT_SYMBOL(mipi_dsi_driver_unregister);
static int __init mipi_dsi_bus_init(void)
{
+ if (IS_ENABLED(CONFIG_OF_DYNAMIC))
+ WARN_ON(of_reconfig_notifier_register(&mipi_dsi_of_notifier));
return bus_register(&mipi_dsi_bus_type);
}
postcore_initcall(mipi_dsi_bus_init);
--
2.45.2.741.gdbec12cfda-goog
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