[PATCH v3 00/10] Barebox Deep-Probe

[PATCH v3 00/10] Barebox Deep-Probe

[Marco Felsch]

Hi all,

this series is our approach to address the EPROBE_DEFER and initcall
shifting problem. I skip the deep-probe explanation here and instead
refer to the detailed commit message of patch 5.

Thanks a lot to Sascha, Ahmad and Lucas for the review feedback :)
Each patch has a own changelog.

Patch 1:
 - Cleanup

Patch 2-3:
 - Those patches were Patch-1 in my v2. Sascha suggested to split it and
   to adapt the commit messages.

Patche 4-6:
 - Deep probe preparation patche

Patch 7:
 - The interesting part of this series. This patch implements the
   deep-probe mechanism and adds helpers to make your board deep-probe
   aware.

Patch 8-9:
 - Adds STM32MP1 and i.MX architecture specific deep-probe code. For
   those architectures this means that we need to populate the
   memory-controller.

Patch 10:
 - Convert the sabrelite board to use the deep_probe mechanism. This can
   be used as example for others :)

Comments and testers are welcome, as always :)

Regards,
  Marco

Lucas Stach (1):
  of: base: move memory init from DT to initcall

Marco Felsch (9):
  imx53: remove unused imx53_add_nand
  of: platform: remove check of already added devices
  of: platform: Keep track of populated platform devices
  of: base: move clock init from of_probe() to barebox_register_of()
  initcall: add of_populate_initcall
  common: add initial barebox deep-probe support
  ARM: i.MX: esdctl: add deep-probe support
  ARM: stm32mp: ddrctrl: add deep-probe support
  ARM: boards: mx6-sabrelite: add deep-probe support

 .../boards/freescale-mx6-sabrelite/board.c    |  24 +-
 arch/arm/mach-imx/esdctl.c                    |  13 +-
 .../arm/mach-imx/include/mach/devices-imx53.h |  27 ---
 arch/arm/mach-stm32mp/ddrctrl.c               |  13 +-
 common/Makefile                               |   1 +
 common/deep-probe.c                           |  34 +++
 drivers/base/driver.c                         |  11 +-
 drivers/clk/clk.c                             |   5 +
 drivers/i2c/i2c.c                             |   8 +
 drivers/of/base.c                             |  28 ++-
 drivers/of/platform.c                         | 216 +++++++++++++++---
 drivers/regulator/core.c                      |   6 +
 drivers/reset/core.c                          |   4 +
 drivers/spi/spi.c                             |   2 +
 include/asm-generic/barebox.lds.h             |  11 +-
 include/deep-probe.h                          |  26 +++
 include/init.h                                |  10 +-
 include/of.h                                  |  29 +++
 18 files changed, 388 insertions(+), 80 deletions(-)
 create mode 100644 common/deep-probe.c
 create mode 100644 include/deep-probe.h

-- 
2.20.1


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[PATCH v3 01/10] imx53: remove unused imx53_add_nand

[Marco Felsch]

The TX53 board was the last user of this function. This board was
converted to device tree based boot by commit 971366078893
("i.MX53/TX53: rework to dts based boot") so we can remove this
legacy helper.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
Changelog:

v3:
- new patch
---
 .../arm/mach-imx/include/mach/devices-imx53.h | 27 -------------------
 1 file changed, 27 deletions(-)

diff --git a/arch/arm/mach-imx/include/mach/devices-imx53.h b/arch/arm/mach-imx/include/mach/devices-imx53.h
index e5c257a40b..3d1e8a27a8 100644
--- a/arch/arm/mach-imx/include/mach/devices-imx53.h
+++ b/arch/arm/mach-imx/include/mach/devices-imx53.h
@@ -77,33 +77,6 @@ static inline struct device_d *imx53_add_mmc3(struct esdhc_platform_data *pdata)
 	return imx_add_esdhc_imx5((void *)MX53_ESDHC4_BASE_ADDR, 3, pdata);
 }
 
-static inline struct device_d *imx53_add_nand(struct imx_nand_platform_data *pdata)
-{
-	struct resource res[] = {
-		{
-			.start = MX53_NFC_BASE_ADDR,
-			.end = MX53_NFC_BASE_ADDR + SZ_4K - 1,
-			.flags = IORESOURCE_MEM,
-		}, {
-			.start = MX53_NFC_AXI_BASE_ADDR,
-			.end = MX53_NFC_AXI_BASE_ADDR + SZ_4K - 1,
-			.flags = IORESOURCE_MEM,
-		},
-	};
-	struct device_d *dev = xzalloc(sizeof(*dev));
-
-	dev->resource = xzalloc(sizeof(struct resource) * ARRAY_SIZE(res));
-	memcpy(dev->resource, res, sizeof(struct resource) * ARRAY_SIZE(res));
-	dev->num_resources = ARRAY_SIZE(res);
-	dev_set_name(dev, "imx_nand");
-	dev->id = DEVICE_ID_DYNAMIC;
-	dev->platform_data = pdata;
-
-	platform_device_register(dev);
-
-	return dev;
-}
-
 static inline struct device_d *imx53_add_kpp(struct matrix_keymap_data *pdata)
 {
 	return imx_add_kpp((void *)MX53_KPP_BASE_ADDR, pdata);
-- 
2.20.1


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[PATCH v3 02/10] of: platform: remove check of already added devices

[Marco Felsch]

This check is a relict of the early barebox device tree days, where
devices were added by machine and/or board code too. The check ensured
too not populate the same device twice. Nowadays _real_ hardware devices
(devices with hardware resources) which are not auto enumerable should
only be added using the device tree. Remove the check to cleanup the
code and to remove looping over each device every time
of_platform_device_create() is called instead of keeping it for legacy
boards/machines. Those legacy boards/machines should be converted
instead.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
Changelog:

v3:
- new patch
---
 drivers/of/platform.c | 31 +------------------------------
 1 file changed, 1 insertion(+), 30 deletions(-)

diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 21c7cce1a5..51781798c6 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -101,7 +101,7 @@ struct device_d *of_platform_device_create(struct device_node *np,
 	struct device_d *dev;
 	struct resource *res = NULL, temp_res;
 	resource_size_t resinval;
-	int i, j, ret, num_reg = 0, match;
+	int i, ret, num_reg = 0;
 
 	if (!of_device_is_available(np))
 		return NULL;
@@ -121,35 +121,6 @@ struct device_d *of_platform_device_create(struct device_node *np,
 				return NULL;
 			}
 		}
-
-		/*
-		 * A device may already be registered as platform_device.
-		 * Instead of registering the same device again, just
-		 * add this node to the existing device.
-		 */
-		for_each_device(dev) {
-			if (!dev->resource)
-				continue;
-
-			for (i = 0, match = 0; i < num_reg; i++)
-				for (j = 0; j < dev->num_resources; j++)
-					if (dev->resource[j].start ==
-						res[i].start &&
-					    dev->resource[j].end ==
-						res[i].end) {
-						match++;
-						break;
-					}
-
-			/* check if all address resources match */
-			if (match == num_reg) {
-				debug("connecting %s to %s\n",
-					np->name, dev_name(dev));
-				dev->device_node = np;
-				free(res);
-				return dev;
-			}
-		}
 	}
 
 	/* setup generic device info */
-- 
2.20.1


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[PATCH v3 03/10] of: platform: Keep track of populated platform devices

[Marco Felsch]

Linux does not allow to populate the same of device more than once.
Linux uses the OF_POPULATED flag for that purpose. Align the logic with
the current linux state with the exception that we are returning the
already created device. This is needed for the later added deep-probe
mechanism.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
Changelog:

v3:
- new patch
---
 drivers/of/platform.c | 20 +++++++++++++++++++-
 include/of.h          |  1 +
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 51781798c6..01de6f98af 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -106,6 +106,13 @@ struct device_d *of_platform_device_create(struct device_node *np,
 	if (!of_device_is_available(np))
 		return NULL;
 
+	/*
+	 * Linux uses the OF_POPULATED flag to skip already populated/created
+	 * devices.
+	 */
+	if (np->dev)
+		return np->dev;
+
 	/* count the io resources */
 	if (of_can_translate_address(np))
 		while (of_address_to_resource(np, num_reg, &temp_res) == 0)
@@ -141,8 +148,10 @@ struct device_d *of_platform_device_create(struct device_node *np,
 		(num_reg) ? &dev->resource[0].start : &resinval);
 
 	ret = platform_device_register(dev);
-	if (!ret)
+	if (!ret) {
+		np->dev = dev;
 		return dev;
+	}
 
 	free(dev);
 	if (num_reg)
@@ -223,6 +232,13 @@ static struct device_d *of_amba_device_create(struct device_node *np)
 	if (!of_device_is_available(np))
 		return NULL;
 
+	/*
+	 * Linux uses the OF_POPULATED flag to skip already populated/created
+	 * devices.
+	 */
+	if (np->dev)
+		return np->dev;
+
 	dev = xzalloc(sizeof(*dev));
 
 	/* setup generic device info */
@@ -246,6 +262,8 @@ static struct device_d *of_amba_device_create(struct device_node *np)
 	if (ret)
 		goto amba_err_free;
 
+	np->dev = &dev->dev;
+
 	return &dev->dev;
 
 amba_err_free:
diff --git a/include/of.h b/include/of.h
index 08a02e1105..d1dbb702d8 100644
--- a/include/of.h
+++ b/include/of.h
@@ -35,6 +35,7 @@ struct device_node {
 	struct list_head parent_list;
 	struct list_head list;
 	phandle phandle;
+	struct device_d *dev;
 };
 
 struct of_device_id {
-- 
2.20.1


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[PATCH v3 04/10] of: base: move memory init from DT to initcall

[Marco Felsch]

From: Lucas Stach <dev@lynxeye.de>

Instead of calling it from of_probe, convert it to a initcall at
the appropriate level. This allows to move of_probe to later in
the init sequence while keeping the memory init at the same place,
which is important as many other drivers need the valid memory area
to be set up properly.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
Changelog:

v2:
- no changes
v3:
- no changes
---
 drivers/of/base.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 5b45c2023f..2a3e34b071 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -2229,10 +2229,13 @@ const struct of_device_id of_default_bus_match_table[] = {
 	}
 };
 
-static void of_probe_memory(void)
+static int of_probe_memory(void)
 {
 	struct device_node *memory = root_node;
 
+	if (!IS_ENABLED(CONFIG_OFDEVICE))
+		return 0;
+
 	/* Parse all available node with "memory" device_type */
 	while (1) {
 		memory = of_find_node_by_type(memory, "memory");
@@ -2241,7 +2244,10 @@ static void of_probe_memory(void)
 
 		of_add_memory(memory, false);
 	}
+
+	return 0;
 }
+mem_initcall(of_probe_memory);
 
 static void of_platform_device_create_root(struct device_node *np)
 {
@@ -2271,8 +2277,6 @@ int of_probe(void)
 	if (of_model)
 		barebox_set_model(of_model);
 
-	of_probe_memory();
-
 	firmware = of_find_node_by_path("/firmware");
 	if (firmware)
 		of_platform_populate(firmware, NULL, NULL);
-- 
2.20.1


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[PATCH v3 05/10] of: base: move clock init from of_probe() to barebox_register_of()

[Marco Felsch]

This is required for the new deep-probe mechanism. Barebox deep-probe
calls of_probe() very late and so clock drivers using the old
CLK_OF_DECLARE_DRIVER() mechanism are added very late. This would break
the deep-probe approach.

Move of_clk_init() and call it right before of_probe() should have no
impact because of_clk_init() depends only on an unflatten dtb.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
Changelog:

v2:
- no changes
v3:
- fix commit message typo
---
 drivers/of/base.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 2a3e34b071..a1903735f4 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1660,8 +1660,10 @@ void barebox_register_of(struct device_node *root)
 	of_fix_tree(root);
 	of_set_root_node(root);
 
-	if (IS_ENABLED(CONFIG_OFDEVICE))
+	if (IS_ENABLED(CONFIG_OFDEVICE)) {
+		of_clk_init(root, NULL);
 		of_probe();
+	}
 }
 
 void barebox_register_fdt(const void *dtb)
@@ -2283,7 +2285,6 @@ int of_probe(void)
 
 	of_platform_device_create_root(root_node);
 
-	of_clk_init(root_node, NULL);
 	of_platform_populate(root_node, of_default_bus_match_table, NULL);
 
 	return 0;
-- 
2.20.1


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[PATCH v3 06/10] initcall: add of_populate_initcall

[Marco Felsch]

Add dedicated initcall for of_probe() which is required for the following
device-on-demand/deep-probe mechanism.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
Changelog:

v2:
- no changes
v3:
- align initcall id with level
---
 include/asm-generic/barebox.lds.h |  1 +
 include/init.h                    | 10 +++++++---
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/include/asm-generic/barebox.lds.h b/include/asm-generic/barebox.lds.h
index 6971e2c1d2..a7d32160d1 100644
--- a/include/asm-generic/barebox.lds.h
+++ b/include/asm-generic/barebox.lds.h
@@ -33,6 +33,7 @@
 	KEEP(*(.initcall.12))			\
 	KEEP(*(.initcall.13))			\
 	KEEP(*(.initcall.14))			\
+	KEEP(*(.initcall.15))			\
 	__barebox_initcalls_end = .;
 
 #define BAREBOX_EXITCALLS			\
diff --git a/include/init.h b/include/init.h
index 2d61bc8963..c695f99867 100644
--- a/include/init.h
+++ b/include/init.h
@@ -47,6 +47,9 @@ typedef void (*exitcall_t)(void);
  * initializes variables that couldn't be statically initialized.
  *
  * This only exists for built-in code, not for modules.
+ *
+ * The only purpose for "of_populate" is to call of_probe() other functions are
+ * not allowed.
  */
 #define pure_initcall(fn)		__define_initcall("0",fn,0)
 
@@ -61,9 +64,10 @@ typedef void (*exitcall_t)(void);
 #define fs_initcall(fn)			__define_initcall("9",fn,9)
 #define device_initcall(fn)		__define_initcall("10",fn,10)
 #define crypto_initcall(fn)		__define_initcall("11",fn,11)
-#define late_initcall(fn)		__define_initcall("12",fn,12)
-#define environment_initcall(fn)	__define_initcall("13",fn,13)
-#define postenvironment_initcall(fn)	__define_initcall("14",fn,14)
+#define of_populate_initcall(fn)	__define_initcall("12",fn,12)
+#define late_initcall(fn)		__define_initcall("13",fn,13)
+#define environment_initcall(fn)	__define_initcall("14",fn,14)
+#define postenvironment_initcall(fn)	__define_initcall("15",fn,15)
 
 #define early_exitcall(fn)		__define_exitcall("0",fn,0)
 #define predevshutdown_exitcall(fn)	__define_exitcall("1",fn,1)
-- 
2.20.1


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[PATCH v3 07/10] common: add initial barebox deep-probe support

[Marco Felsch]

The barebox 'deep probe' or 'probe on demand' mechanism is the answer of
unwanted -EPROBE_DEFER failures. The EPROBE_DEFER error code was
introduced by commit ab3da15bc14c ("base: Introduce deferred probing")
and since then it causes a few problems.

The error is returned if either the device is not yet present or the
driver is not yet registered. This makes sense on linux systems where
modules and hot-plug devices are used very often but not for barebox.
The module support is rarely used and devices aren't hot pluggable.

The current barebox behaviour populates all devices before the drivers
are registered so all devices are present during the driver
registration. So the driver probe() function gets called immediately
after the driver registration and causes the -EPROBE_DEFER error if this
driver depends on an other not yet registered driver.

To get rid of the EPROBE_DEFER error code we need to reorder the device
population and the driver registration. All drivers must be registered
first. In an ideal world all driver can be registered by the same
initcall level. Then devices are getting populated which causes calling
the driver probe() function but this time resources/devices are created
on demand if not yet available.

Dependencies between devices are normally expressed as references to
other device nodes. With deep probe barebox provides helper functions
which take a device node and probe the device behind that node if
necessary. This means instead of returning -EPROBE_DEFER, we can now
make the desired resources available once we need them.

If the resource can't be created we are returning -ENODEV since we are
not supporting hot-plugging. Dropping EPROBE_DEFER is the long-term
goal, avoid initcall shifting is the short-term goal.

Call it deep-probe since the on-demand device creation can create very
deep stacks. This commit adds the initial support for: spi, i2c, reset,
regulator and clk resource on-demand creation. The deep-probe mechanism
must be enabled for each board to avoid breaking changes using
deep_probe_enable(). This can be changed later after all boards are
converted to the new mechanism.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
Changelog:

v2:
- add deep-probe state to verify it once
- use a linker list array instead of initcalls and runtime allocation
- make of_device_create_on_demand an internal function
- convert to of_device_ensure_probed* and of_devices_ensure_probed*
- add missing function docs
- force the existence of the driver to avoid EPROBE_DEFER (see long-term
  goal)
- return int instead of device_d
- fix stub funcs
- add BUG_ON() to track undefined behaviour
- add comment to of_platform_device_create() to make it clear that
  calling it again for an already populated device is not allowed
- i2c: only set of_node->dev if it is available

v3:
- s/DEEP_PROBE_UNKONW/DEEP_PROBE_UNKONWN/
- return retval of of_probe() during barebox_of_populate()
- fix comment typos
- make use of __UNIQUE_ID macro to simplify BAREBOX_DEEP_PROBE_ENABLE
- make deep_probe_entry's static -> local
- drop unrelated changes
- fix commit message typo
- be a bit smarter handling while handling deep_probe_state
---
 common/Makefile                   |   1 +
 common/deep-probe.c               |  34 ++++++
 drivers/base/driver.c             |  11 +-
 drivers/clk/clk.c                 |   5 +
 drivers/i2c/i2c.c                 |   8 ++
 drivers/of/base.c                 |  13 ++-
 drivers/of/platform.c             | 165 ++++++++++++++++++++++++++++++
 drivers/regulator/core.c          |   6 ++
 drivers/reset/core.c              |   4 +
 drivers/spi/spi.c                 |   2 +
 include/asm-generic/barebox.lds.h |  10 +-
 include/deep-probe.h              |  26 +++++
 include/of.h                      |  28 +++++
 13 files changed, 310 insertions(+), 3 deletions(-)
 create mode 100644 common/deep-probe.c
 create mode 100644 include/deep-probe.h

diff --git a/common/Makefile b/common/Makefile
index c3ae3ca1b9..8525240422 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -3,6 +3,7 @@ obj-y				+= memory_display.o
 pbl-$(CONFIG_PBL_CONSOLE)	+= memory_display.o
 obj-y				+= clock.o
 obj-y				+= console_common.o
+obj-y				+= deep-probe.o
 obj-y				+= startup.o
 obj-y				+= misc.o
 obj-pbl-y			+= memsize.o
diff --git a/common/deep-probe.c b/common/deep-probe.c
new file mode 100644
index 0000000000..9fc67f170c
--- /dev/null
+++ b/common/deep-probe.c
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <common.h>
+#include <deep-probe.h>
+#include <of.h>
+
+enum deep_probe_state {
+	DEEP_PROBE_UNKONWN = -1,
+	DEEP_PROBE_NOT_SUPPORTED,
+	DEEP_PROBE_SUPPORTED
+};
+
+static enum deep_probe_state boardstate = DEEP_PROBE_UNKONWN;
+
+bool deep_probe_is_supported(void)
+{
+	struct deep_probe_entry *board;
+
+	if (boardstate > DEEP_PROBE_UNKONWN)
+		return boardstate;
+
+	/* determine boardstate */
+	for (board = &__barebox_deep_probe_start;
+	     board != &__barebox_deep_probe_end; board++) {
+		if (of_machine_is_compatible(board->compatible)) {
+			boardstate = DEEP_PROBE_SUPPORTED;
+			return true;
+		}
+	}
+
+	boardstate = DEEP_PROBE_NOT_SUPPORTED;
+	return false;
+}
+EXPORT_SYMBOL_GPL(deep_probe_is_supported);
diff --git a/drivers/base/driver.c b/drivers/base/driver.c
index 3205bbc3c3..acec5f9fb8 100644
--- a/drivers/base/driver.c
+++ b/drivers/base/driver.c
@@ -21,6 +21,7 @@
 
 #include <common.h>
 #include <command.h>
+#include <deep-probe.h>
 #include <driver.h>
 #include <malloc.h>
 #include <console.h>
@@ -95,7 +96,15 @@ int device_probe(struct device_d *dev)
 	if (ret == -EPROBE_DEFER) {
 		list_del(&dev->active);
 		list_add(&dev->active, &deferred);
-		dev_dbg(dev, "probe deferred\n");
+
+		/*
+		 * -EPROBE_DEFER should never appear on a deep-probe machine so
+		 * inform the user immediately.
+		 */
+		if (deep_probe_is_supported())
+			dev_warn(dev, "probe deferred\n");
+		else
+			dev_dbg(dev, "probe deferred\n");
 		return ret;
 	}
 
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index b04d44593b..e40dfae9ce 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -439,6 +439,11 @@ struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
 {
 	struct of_clk_provider *provider;
 	struct clk *clk = ERR_PTR(-EPROBE_DEFER);
+	int ret;
+
+	ret = of_device_ensure_probed(clkspec->np);
+	if (ret)
+		return ERR_PTR(ret);
 
 	/* Check if we have such a provider in our array */
 	list_for_each_entry(provider, &of_clk_providers, link) {
diff --git a/drivers/i2c/i2c.c b/drivers/i2c/i2c.c
index 57d8c7017f..12aac42794 100644
--- a/drivers/i2c/i2c.c
+++ b/drivers/i2c/i2c.c
@@ -407,6 +407,9 @@ static struct i2c_client *i2c_new_device(struct i2c_adapter *adapter,
 	}
 	client->dev.info = i2c_info;
 
+	if (chip->of_node)
+		chip->of_node->dev = &client->dev;
+
 	return client;
 }
 
@@ -548,6 +551,11 @@ struct i2c_adapter *i2c_get_adapter(int busnum)
 struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
 {
 	struct i2c_adapter *adap;
+	int ret;
+
+	ret = of_device_ensure_probed(node);
+	if (ret)
+		return ERR_PTR(ret);
 
 	for_each_i2c_adapter(adap)
 		if (adap->dev.device_node == node)
diff --git a/drivers/of/base.c b/drivers/of/base.c
index a1903735f4..5bb07ef743 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -15,6 +15,7 @@
  * GNU General Public License for more details.
  */
 #include <common.h>
+#include <deep-probe.h>
 #include <of.h>
 #include <of_address.h>
 #include <errno.h>
@@ -1652,6 +1653,15 @@ int of_set_root_node(struct device_node *node)
 	return 0;
 }
 
+static int barebox_of_populate(void)
+{
+	if (IS_ENABLED(CONFIG_OFDEVICE) && deep_probe_is_supported())
+		return of_probe();
+
+	return 0;
+}
+of_populate_initcall(barebox_of_populate);
+
 void barebox_register_of(struct device_node *root)
 {
 	if (root_node)
@@ -1662,7 +1672,8 @@ void barebox_register_of(struct device_node *root)
 
 	if (IS_ENABLED(CONFIG_OFDEVICE)) {
 		of_clk_init(root, NULL);
-		of_probe();
+		if (!deep_probe_is_supported())
+			of_probe();
 	}
 }
 
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 01de6f98af..700dc4ac04 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -15,6 +15,7 @@
  * GNU General Public License for more details.
  */
 #include <common.h>
+#include <deep-probe.h>
 #include <malloc.h>
 #include <of.h>
 #include <of_address.h>
@@ -29,6 +30,12 @@
 struct device_d *of_find_device_by_node(struct device_node *np)
 {
 	struct device_d *dev;
+	int ret;
+
+	ret = of_device_ensure_probed(np);
+	if (ret)
+		return NULL;
+
 	for_each_device(dev)
 		if (dev->device_node == np)
 			return dev;
@@ -353,3 +360,161 @@ int of_platform_populate(struct device_node *root,
 	return rc;
 }
 EXPORT_SYMBOL_GPL(of_platform_populate);
+
+static struct device_d *of_device_create_on_demand(struct device_node *np)
+{
+	struct device_node *parent;
+	struct device_d *parent_dev, *dev;
+
+	parent = of_get_parent(np);
+	if (!parent)
+		return NULL;
+
+	/* Create all parent devices needed for the requested device */
+	parent_dev = parent->dev ? : of_device_create_on_demand(parent);
+	if (IS_ERR(parent_dev))
+		return parent_dev;
+
+	/*
+	 * Parent devices like i2c/spi controllers are populating their own
+	 * devices. So it can be that the requested device already exist after
+	 * the parent device creation.
+	 */
+	if (np->dev)
+		return np->dev;
+
+	pr_debug("%s: Create %s (%s) on demand\n", __func__,
+		 np->name, np->full_name);
+
+	if (of_device_is_compatible(np, "arm,primecell"))
+		dev = of_amba_device_create(np);
+	else
+		dev = of_platform_device_create(np, parent_dev);
+
+	return dev ? : ERR_PTR(-ENODEV);
+}
+
+/**
+ * of_device_ensure_probed() - ensures that a device is probed
+ *
+ * @np: the device_node handle which should be probed
+ *
+ * Ensures that the device is populated and probed so frameworks can make use of
+ * it.
+ *
+ * Return: %0 on success
+ *	   %-ENODEV if either the device can't be populated, the driver is
+ *	     missing or the driver probe returns an error.
+ */
+int of_device_ensure_probed(struct device_node *np)
+{
+	struct device_d *dev;
+
+	if (!deep_probe_is_supported())
+		return 0;
+
+	dev = of_device_create_on_demand(np);
+	if (IS_ERR(dev))
+		return PTR_ERR(dev);
+
+	BUG_ON(!dev);
+
+	/*
+	 * The deep-probe mechanism relies on the fact that all necessary
+	 * drivers are added before the device creation. Furthermore deep-probe
+	 * is the answer to the EPROBE_DEFER errno so we must ensure that the
+	 * driver was probed successfully after the device creation. Both
+	 * requirements are fulfilled if 'dev->driver' is not NULL.
+	 */
+	if (!dev->driver)
+		return -ENODEV;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_device_ensure_probed);
+
+/**
+ * of_device_ensure_probed_by_alias() - ensures that a device is probed
+ *
+ * @alias: the alias string to search for a device
+ *
+ * The function search for a given alias string and ensures that the device is
+ * populated and probed if found.
+ *
+ * Return: %0 on success
+ *	   %-ENODEV if either the device can't be populated, the driver is
+ *	     missing or the driver probe returns an error
+ *	   %-EINVAL if alias can't be found
+ */
+int of_device_ensure_probed_by_alias(const char *alias)
+{
+	struct device_node *dev_node;
+
+	dev_node = of_find_node_by_alias(NULL, alias);
+	if (!dev_node)
+		return -EINVAL;
+
+	return of_device_ensure_probed(dev_node);
+}
+EXPORT_SYMBOL_GPL(of_device_ensure_probed_by_alias);
+
+/**
+ * of_devices_ensure_probed_by_dev_id() - ensures that a devices are probed
+ *
+ * @np: the start point device_node handle
+ * @ids: the matching 'struct of_device_id' ids
+ *
+ * The function start searching the device tree from @np and populates and
+ * probes devices which matches @ids.
+ *
+ * Return: %0 on success
+ *	   %-ENODEV if either the device wasn't found, can't be populated,
+ *	     the driver is missing or the driver probe returns an error
+ */
+int of_devices_ensure_probed_by_dev_id(struct device_node *np,
+				       const struct of_device_id *ids)
+{
+	struct device_node *child;
+
+	if (of_match_node(ids, np))
+		return of_device_ensure_probed(np);
+
+	for_each_child_of_node(np, child) {
+		int ret;
+
+		ret = of_devices_ensure_probed_by_dev_id(child, ids);
+		if (!ret)
+			return 0;
+	}
+
+	return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(of_devices_ensure_probed_by_dev_id);
+
+/**
+ * of_devices_ensure_probed_by_property() - ensures that a devices are probed
+ *
+ * @property_name: The property name to search for
+ *
+ * The function start searching the whole device tree and populates and probe
+ * devices which matches @property_name.
+ *
+ * Return: %0 on success
+ *	   %-ENODEV if either the device wasn't found, can't be populated,
+ *	     the driver is missing or the driver probe returns an error
+ */
+int of_devices_ensure_probed_by_property(const char *property_name)
+{
+	struct device_node *node;
+
+	for_each_node_with_property(node, property_name) {
+		int ret;
+
+		ret = of_device_ensure_probed(node);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_devices_ensure_probed_by_property);
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 6ea21a4609..803b66bd0c 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -175,6 +175,7 @@ int of_regulator_register(struct regulator_dev *rd, struct device_node *node)
 		return PTR_ERR(ri);
 
 	ri->node = node;
+	node->dev = rd->dev;
 
 	of_property_read_u32(node, "regulator-enable-ramp-delay",
 			&ri->enable_time_us);
@@ -191,6 +192,7 @@ static struct regulator_internal *of_regulator_get(struct device_d *dev, const c
 	char *propname;
 	struct regulator_internal *ri;
 	struct device_node *node;
+	int ret;
 
 	propname = basprintf("%s-supply", supply);
 
@@ -222,6 +224,10 @@ static struct regulator_internal *of_regulator_get(struct device_d *dev, const c
 		goto out;
 	}
 
+	ret = of_device_ensure_probed(node);
+	if (ret)
+		return ERR_PTR(ret);
+
 	list_for_each_entry(ri, &regulator_list, list) {
 		if (ri->node == node) {
 			dev_dbg(dev, "Using %s regulator from %s\n",
diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index 26a54f21df..e2edca6658 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -168,6 +168,10 @@ static struct reset_control *of_reset_control_get(struct device_node *node,
 	if (ret)
 		return ERR_PTR(ret);
 
+	ret = of_device_ensure_probed(args.np);
+	if (ret)
+		return ERR_PTR(ret);
+
 	rcdev = NULL;
 	list_for_each_entry(r, &reset_controller_list, list) {
 		if (args.np == r->of_node) {
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 8421d9d7c1..d1d3bdcc41 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -107,6 +107,8 @@ struct spi_device *spi_new_device(struct spi_controller *ctrl,
 	if (status)
 		goto fail;
 
+	chip->device_node->dev = &proxy->dev;
+
 	return proxy;
 fail:
 	free(proxy);
diff --git a/include/asm-generic/barebox.lds.h b/include/asm-generic/barebox.lds.h
index a7d32160d1..c5f9d97547 100644
--- a/include/asm-generic/barebox.lds.h
+++ b/include/asm-generic/barebox.lds.h
@@ -114,6 +114,13 @@
 	KEEP(*(.rsa_keys.rodata.*));		\
 	__rsa_keys_end = .;			\
 
+#define BAREBOX_DEEP_PROBE			\
+	STRUCT_ALIGN();				\
+	__barebox_deep_probe_start = .;		\
+	KEEP(*(SORT_BY_NAME(.barebox_deep_probe*)))	\
+	__barebox_deep_probe_end = .;
+
+
 #ifdef CONFIG_CONSTRUCTORS
 #define KERNEL_CTORS()  . = ALIGN(8);                      \
 			__ctors_start = .;                 \
@@ -136,7 +143,8 @@
 	BAREBOX_CLK_TABLE			\
 	BAREBOX_DTB				\
 	BAREBOX_RSA_KEYS			\
-	BAREBOX_PCI_FIXUP
+	BAREBOX_PCI_FIXUP			\
+	BAREBOX_DEEP_PROBE
 
 #if defined(CONFIG_ARCH_BAREBOX_MAX_BARE_INIT_SIZE) && \
 CONFIG_ARCH_BAREBOX_MAX_BARE_INIT_SIZE < CONFIG_BAREBOX_MAX_BARE_INIT_SIZE
diff --git a/include/deep-probe.h b/include/deep-probe.h
new file mode 100644
index 0000000000..a646c10340
--- /dev/null
+++ b/include/deep-probe.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __DEEP_PROBE_H
+#define __DEEP_PROBE_H
+
+#include <linux/stringify.h>
+#include <linux/types.h>
+
+struct deep_probe_entry {
+	const char *compatible;
+};
+
+bool deep_probe_is_supported(void);
+
+extern struct deep_probe_entry __barebox_deep_probe_start;
+extern struct deep_probe_entry __barebox_deep_probe_end;
+
+#define __BAREBOX_DEEP_PROBE_ENABLE(_entry,_compatible)			\
+	static const struct deep_probe_entry _entry			\
+	__attribute__ ((used,section (".barebox_deep_probe_" __stringify(_entry)))) = { \
+		.compatible = _compatible,				\
+	}
+
+#define BAREBOX_DEEP_PROBE_ENABLE(_compatible)	\
+	__BAREBOX_DEEP_PROBE_ENABLE(__UNIQUE_ID(deepprobe),_compatible)
+
+#endif /* __DEEP_PROBE_H */
diff --git a/include/of.h b/include/of.h
index d1dbb702d8..1531853d24 100644
--- a/include/of.h
+++ b/include/of.h
@@ -274,6 +274,12 @@ extern struct device_d *of_device_enable_and_register_by_name(const char *name);
 extern struct device_d *of_device_enable_and_register_by_alias(
 							const char *alias);
 
+extern int of_device_ensure_probed(struct device_node *np);
+extern int of_device_ensure_probed_by_alias(const char *alias);
+extern int of_devices_ensure_probed_by_property(const char *property_name);
+extern int of_devices_ensure_probed_by_dev_id(struct device_node *np,
+					      const struct of_device_id *ids);
+
 struct cdev *of_parse_partition(struct cdev *cdev, struct device_node *node);
 int of_parse_partitions(struct cdev *cdev, struct device_node *node);
 int of_partitions_register_fixup(struct cdev *cdev);
@@ -345,6 +351,28 @@ static inline struct device_d *of_platform_device_create(struct device_node *np,
 	return NULL;
 }
 
+static inline int of_device_ensure_probed(struct device_node *np)
+{
+	return 0;
+}
+
+static inline int of_device_ensure_probed_by_alias(const char *alias)
+{
+	return 0;
+}
+
+static inline int of_devices_ensure_probed_by_property(const char *property_name)
+{
+	return 0;
+}
+
+static inline int
+of_devices_ensure_probed_by_dev_id(struct device_node *np,
+				   const struct of_device_id *ids)
+{
+	return 0;
+}
+
 static inline int of_bus_n_addr_cells(struct device_node *np)
 {
 	return 0;
-- 
2.20.1


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[PATCH v3 08/10] ARM: i.MX: esdctl: add deep-probe support

[Marco Felsch]

In case of deep-probe we have to ensure that the memory device is
available after the mem_initcall().

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
Changelog:

v2
- convert to of_devices_ensure_probed_by_dev_id()
- drop use-less deep-probe include
v3:
- no changes
---
 arch/arm/mach-imx/esdctl.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-imx/esdctl.c b/arch/arm/mach-imx/esdctl.c
index 426a96a3c4..1a3af9718b 100644
--- a/arch/arm/mach-imx/esdctl.c
+++ b/arch/arm/mach-imx/esdctl.c
@@ -703,7 +703,18 @@ static struct driver_d imx_esdctl_driver = {
 	.of_compatible = DRV_OF_COMPAT(imx_esdctl_dt_ids),
 };
 
-mem_platform_driver(imx_esdctl_driver);
+static int imx_esdctl_init(void)
+{
+	int ret;
+
+	ret = platform_driver_register(&imx_esdctl_driver);
+	if (ret)
+		return ret;
+
+	return of_devices_ensure_probed_by_dev_id(of_get_root_node(),
+						  imx_esdctl_dt_ids);
+}
+mem_initcall(imx_esdctl_init);
 
 /*
  * The i.MX SoCs usually have two SDRAM chipselects. The following
-- 
2.20.1


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[PATCH v3 09/10] ARM: stm32mp: ddrctrl: add deep-probe support

[Marco Felsch]

In case of deep-probe we have to ensure that the memory device is
available after the mem_initcall().

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
Changelog:

v2:
- convert to of_devices_ensure_probed_by_dev_id()
- drop use-less deep-probe include
v3:
- no changes
---
 arch/arm/mach-stm32mp/ddrctrl.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-stm32mp/ddrctrl.c b/arch/arm/mach-stm32mp/ddrctrl.c
index 646fe4401a..a7a87ef8f8 100644
--- a/arch/arm/mach-stm32mp/ddrctrl.c
+++ b/arch/arm/mach-stm32mp/ddrctrl.c
@@ -148,4 +148,15 @@ static struct driver_d stm32mp1_ddr_driver = {
 	.of_compatible = DRV_OF_COMPAT(stm32mp1_ddr_dt_ids),
 };
 
-mem_platform_driver(stm32mp1_ddr_driver);
+static int stm32mp1_ddr_init(void)
+{
+	int ret;
+
+	ret = platform_driver_register(&stm32mp1_ddr_driver);
+	if (ret)
+		return ret;
+
+	return of_devices_ensure_probed_by_dev_id(of_get_root_node(),
+						  stm32mp1_ddr_dt_ids);
+}
+mem_initcall(stm32mp1_ddr_init);
-- 
2.20.1


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[PATCH v3 10/10] ARM: boards: mx6-sabrelite: add deep-probe support

[Marco Felsch]

Explicit request the required gpio resources instead of relying on their
existence based on the initcall level.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
Changelog:

v2:
- convert to new macro name
- convert to new api
v3:
- convert to new BAREBOX_DEEP_PROBE_ENABLE macro
---
 .../boards/freescale-mx6-sabrelite/board.c    | 24 ++++++++++++-------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/arch/arm/boards/freescale-mx6-sabrelite/board.c b/arch/arm/boards/freescale-mx6-sabrelite/board.c
index 1b39ef82c6..0a2df391e9 100644
--- a/arch/arm/boards/freescale-mx6-sabrelite/board.c
+++ b/arch/arm/boards/freescale-mx6-sabrelite/board.c
@@ -13,7 +13,9 @@
 #include <mach/bbu.h>
 #include <asm/armlinux.h>
 #include <generated/mach-types.h>
+#include <of.h>
 #include <partition.h>
+#include <deep-probe.h>
 #include <linux/phy.h>
 #include <asm/io.h>
 #include <asm/mmu.h>
@@ -98,10 +100,6 @@ static int sabrelite_ksz9021rn_setup(void)
 {
 	int ret;
 
-	if (!of_machine_is_compatible("fsl,imx6q-sabrelite") &&
-	    !of_machine_is_compatible("fsl,imx6dl-sabrelite"))
-		return 0;
-
 	mxc_iomux_v3_setup_multiple_pads(sabrelite_enet_gpio_pads,
 			ARRAY_SIZE(sabrelite_enet_gpio_pads));
 
@@ -118,11 +116,6 @@ static int sabrelite_ksz9021rn_setup(void)
 
 	return 0;
 }
-/*
- * Do this before the fec initializes but after our
- * gpios are available.
- */
-fs_initcall(sabrelite_ksz9021rn_setup);
 
 static void sabrelite_ehci_init(void)
 {
@@ -134,10 +127,20 @@ static void sabrelite_ehci_init(void)
 
 static int sabrelite_devices_init(void)
 {
+	int ret;
+
 	if (!of_machine_is_compatible("fsl,imx6q-sabrelite") &&
 	    !of_machine_is_compatible("fsl,imx6dl-sabrelite"))
 		return 0;
 
+	ret = of_devices_ensure_probed_by_property("gpio-controller");
+	if (ret)
+		return ret;
+
+	ret = sabrelite_ksz9021rn_setup();
+	if (ret)
+		return ret;
+
 	sabrelite_ehci_init();
 
 	armlinux_set_architecture(3769);
@@ -163,3 +166,6 @@ static int sabrelite_coredevices_init(void)
 	return 0;
 }
 coredevice_initcall(sabrelite_coredevices_init);
+
+BAREBOX_DEEP_PROBE_ENABLE("fsl,imx6q-sabrelite");
+BAREBOX_DEEP_PROBE_ENABLE("fsl,imx6dl-sabrelite");
-- 
2.20.1


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Re: [PATCH v3 07/10] common: add initial barebox deep-probe support

[Sascha Hauer]

Hi Marco,

Looks mostly good, only a few things, mostly nitpicks, left.

> +int of_device_ensure_probed_by_alias(const char *alias)
> +{
> +	struct device_node *dev_node;
> +
> +	dev_node = of_find_node_by_alias(NULL, alias);
> +	if (!dev_node)
> +		return -EINVAL;
> +
> +	return of_device_ensure_probed(dev_node);
> +}
> +EXPORT_SYMBOL_GPL(of_device_ensure_probed_by_alias);
> +
> +/**
> + * of_devices_ensure_probed_by_dev_id() - ensures that a devices are probed

s/a//

> + *
> + * @np: the start point device_node handle
> + * @ids: the matching 'struct of_device_id' ids
> + *
> + * The function start searching the device tree from @np and populates and
> + * probes devices which matches @ids.

s/matches/match/

> + *
> + * Return: %0 on success
> + *	   %-ENODEV if either the device wasn't found, can't be populated,
> + *	     the driver is missing or the driver probe returns an error
> + */
> +int of_devices_ensure_probed_by_dev_id(struct device_node *np,
> +				       const struct of_device_id *ids)
> +{
> +	struct device_node *child;
> +
> +	if (of_match_node(ids, np))
> +		return of_device_ensure_probed(np);
> +
> +	for_each_child_of_node(np, child) {
> +		int ret;
> +
> +		ret = of_devices_ensure_probed_by_dev_id(child, ids);
> +		if (!ret)
> +			return 0;
> +	}
> +
> +	return -ENODEV;
> +}
> +EXPORT_SYMBOL_GPL(of_devices_ensure_probed_by_dev_id);

I think you want to use for_each_matching_node() here which iterates
over the tree without recursion.

> +
> +/**
> + * of_devices_ensure_probed_by_property() - ensures that a devices are probed

s/a//

> + *
> + * @property_name: The property name to search for
> + *
> + * The function start searching the whole device tree and populates and probe

s/probe/probes/

> + * devices which matches @property_name.

s/matches/match/

Sascha

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

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Re: [PATCH v3 07/10] common: add initial barebox deep-probe support

[Sascha Hauer]

On Wed, Oct 21, 2020 at 01:58:10PM +0200, Marco Felsch wrote:
> The barebox 'deep probe' or 'probe on demand' mechanism is the answer of
> +
> +/**
> + * of_devices_ensure_probed_by_dev_id() - ensures that a devices are probed
> + *
> + * @np: the start point device_node handle
> + * @ids: the matching 'struct of_device_id' ids
> + *
> + * The function start searching the device tree from @np and populates and
> + * probes devices which matches @ids.
> + *
> + * Return: %0 on success
> + *	   %-ENODEV if either the device wasn't found, can't be populated,
> + *	     the driver is missing or the driver probe returns an error
> + */
> +int of_devices_ensure_probed_by_dev_id(struct device_node *np,
> +				       const struct of_device_id *ids)
> +{
> +	struct device_node *child;
> +
> +	if (of_match_node(ids, np))
> +		return of_device_ensure_probed(np);
> +
> +	for_each_child_of_node(np, child) {
> +		int ret;
> +
> +		ret = of_devices_ensure_probed_by_dev_id(child, ids);
> +		if (!ret)
> +			return 0;
> +	}

Ok, this needs fixing. After of_devices_ensure_probed_by_dev_id()
returns successfully you must continue the loop, otherwise only the
first matching devices on each level is probed.

Sascha


-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

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