[PATCH U-Boot v2019.04-aspeed-openbmc 0/6] Add GPIO hog support

[PATCH U-Boot v2019.04-aspeed-openbmc 0/6] Add GPIO hog support

[Eddie James]

This series adds support for GPIO hogging based on upstream patches.
I added additional support for hogging in the SPL, and enabled this
for the AST2600 "rainier" openbmc platform.

Eddie James (3):
  gpio: Enable hogging support in SPL
  Add GPIO hogging support for AST2600 openbmc config
  ast2600: Add GPIO controller and hog TPM reset pin

Heiko Schocher (2):
  gpio: add gpio-hog support
  gpio: fixes for gpio-hog support

Jean-Jacques Hiblot (1):
  dm: Add a No-op uclass

 arch/arm/dts/ast2600-rainier.dts           |  11 +
 arch/sandbox/dts/test.dts                  |  12 ++
 common/board_r.c                           |   6 +
 common/spl/spl.c                           |   7 +
 configs/ast2600_openbmc_spl_emmc_defconfig |   4 +-
 doc/device-tree-bindings/gpio/gpio.txt     |  60 ++++++
 drivers/core/uclass.c                      |   5 +
 drivers/gpio/Kconfig                       |  20 ++
 drivers/gpio/gpio-uclass.c                 | 230 +++++++++++++++++++--
 include/asm-generic/gpio.h                 |  34 +++
 include/dm/uclass-id.h                     |   1 +
 test/dm/Makefile                           |   1 +
 test/dm/nop.c                              |  73 +++++++
 13 files changed, 447 insertions(+), 17 deletions(-)
 create mode 100644 test/dm/nop.c

-- 
2.27.0

[PATCH U-Boot v2019.04-aspeed-openbmc 1/6] dm: Add a No-op uclass

[Eddie James]

From: Jean-Jacques Hiblot <jjhiblot@ti.com>

This uclass is intended for devices that do not need any features from the
uclass, including binding children.
This will typically be used by devices that are used to bind child devices
but do not use dm_scan_fdt_dev() to do it. That is for example the case of
several USB wrappers that have 2 child devices (1 for device and 1 for
host) but bind only one at a any given time.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
---
 arch/sandbox/dts/test.dts | 12 +++++++
 drivers/core/uclass.c     |  5 +++
 include/dm/uclass-id.h    |  1 +
 test/dm/Makefile          |  1 +
 test/dm/nop.c             | 73 +++++++++++++++++++++++++++++++++++++++
 5 files changed, 92 insertions(+)
 create mode 100644 test/dm/nop.c

diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index 87d8e5bcc9..b705161086 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -400,6 +400,18 @@
 		sandbox,silent;	/* Don't emit sounds while testing */
 	};
 
+	nop-test_0 {
+		compatible = "sandbox,nop_sandbox1";
+		nop-test_1 {
+			compatible = "sandbox,nop_sandbox2";
+			bind = "True";
+		};
+		nop-test_2 {
+			compatible = "sandbox,nop_sandbox2";
+			bind = "False";
+		};
+	};
+
 	misc-test {
 		compatible = "sandbox,misc_sandbox";
 	};
diff --git a/drivers/core/uclass.c b/drivers/core/uclass.c
index fc3157de39..dc9eb62893 100644
--- a/drivers/core/uclass.c
+++ b/drivers/core/uclass.c
@@ -757,3 +757,8 @@ int uclass_pre_remove_device(struct udevice *dev)
 	return 0;
 }
 #endif
+
+UCLASS_DRIVER(nop) = {
+	.id		= UCLASS_NOP,
+	.name		= "nop",
+};
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 13ae6e1e4c..281c0d6ed2 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -62,6 +62,7 @@ enum uclass_id {
 	UCLASS_MMC,		/* SD / MMC card or chip */
 	UCLASS_MOD_EXP,		/* RSA Mod Exp device */
 	UCLASS_MTD,		/* Memory Technology Device (MTD) device */
+	UCLASS_NOP,		/* No-op devices */
 	UCLASS_NORTHBRIDGE,	/* Intel Northbridge / SDRAM controller */
 	UCLASS_NVME,		/* NVM Express device */
 	UCLASS_PANEL,		/* Display panel, such as an LCD */
diff --git a/test/dm/Makefile b/test/dm/Makefile
index 49857c5092..aeb3aa0ca7 100644
--- a/test/dm/Makefile
+++ b/test/dm/Makefile
@@ -3,6 +3,7 @@
 # Copyright (c) 2013 Google, Inc
 
 obj-$(CONFIG_UT_DM) += bus.o
+obj-$(CONFIG_UT_DM) += nop.o
 obj-$(CONFIG_UT_DM) += test-driver.o
 obj-$(CONFIG_UT_DM) += test-fdt.o
 obj-$(CONFIG_UT_DM) += test-main.o
diff --git a/test/dm/nop.c b/test/dm/nop.c
new file mode 100644
index 0000000000..2df29f3d15
--- /dev/null
+++ b/test/dm/nop.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Test for the NOP uclass
+ *
+ * (C) Copyright 2019 - Texas Instruments Incorporated - http://www.ti.com/
+ * Jean-Jacques Hiblot <jjhiblot@ti.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/ofnode.h>
+#include <dm/lists.h>
+#include <dm/device.h>
+#include <dm/test.h>
+#include <misc.h>
+#include <test/ut.h>
+
+static int noptest_bind(struct udevice *parent)
+{
+	ofnode ofnode = dev_read_first_subnode(parent);
+
+	while (ofnode_valid(ofnode)) {
+		struct udevice *dev;
+		const char *bind_flag = ofnode_read_string(ofnode, "bind");
+
+		if (bind_flag && (strcmp(bind_flag, "True") == 0))
+			lists_bind_fdt(parent, ofnode, &dev, false);
+		ofnode = dev_read_next_subnode(ofnode);
+	}
+
+	return 0;
+}
+
+static const struct udevice_id noptest1_ids[] = {
+	{
+		.compatible = "sandbox,nop_sandbox1",
+	},
+	{ }
+};
+
+U_BOOT_DRIVER(noptest_drv1) = {
+	.name	= "noptest1_drv",
+	.of_match	= noptest1_ids,
+	.id	= UCLASS_NOP,
+	.bind = noptest_bind,
+};
+
+static const struct udevice_id noptest2_ids[] = {
+	{
+		.compatible = "sandbox,nop_sandbox2",
+	},
+	{ }
+};
+
+U_BOOT_DRIVER(noptest_drv2) = {
+	.name	= "noptest2_drv",
+	.of_match	= noptest2_ids,
+	.id	= UCLASS_NOP,
+};
+
+static int dm_test_nop(struct unit_test_state *uts)
+{
+	struct udevice *dev;
+
+	ut_assertok(uclass_get_device_by_name(UCLASS_NOP, "nop-test_0", &dev));
+	ut_assertok(uclass_get_device_by_name(UCLASS_NOP, "nop-test_1", &dev));
+	ut_asserteq(-ENODEV,
+		    uclass_get_device_by_name(UCLASS_NOP, "nop-test_2", &dev));
+
+	return 0;
+}
+
+DM_TEST(dm_test_nop, DM_TESTF_FLAT_TREE | DM_TESTF_SCAN_FDT);
-- 
2.27.0

Re: [PATCH U-Boot v2019.04-aspeed-openbmc 1/6] dm: Add a No-op uclass

[Andrew Jeffery]

On Tue, 25 Jan 2022, at 05:44, Eddie James wrote:
> From: Jean-Jacques Hiblot <jjhiblot@ti.com>
>
> This uclass is intended for devices that do not need any features from the
> uclass, including binding children.
> This will typically be used by devices that are used to bind child devices
> but do not use dm_scan_fdt_dev() to do it. That is for example the case of
> several USB wrappers that have 2 child devices (1 for device and 1 for
> host) but bind only one at a any given time.

(cherry-picked from 07e33711fec4f1106f36805b5dc830da07c783c5) ?

> Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
> Reviewed-by: Simon Glass <sjg@chromium.org>

[PATCH U-Boot v2019.04-aspeed-openbmc 2/6] gpio: add gpio-hog support

[Eddie James]

From: Heiko Schocher <hs@denx.de>

add gpio-hog support. GPIO hogging is a mechanism
providing automatic GPIO request and configuration
as part of the gpio-controller's driver probe function.

for more infos see:
doc/device-tree-bindings/gpio/gpio.txt

Signed-off-by: Heiko Schocher <hs@denx.de>
Tested-by: Michal Simek <michal.simek@xilinx.com> (zcu102)
Tested-by: Patrick Delaunay <patrick.delaunay@st.com>
---
 common/board_r.c                       |   6 +
 doc/device-tree-bindings/gpio/gpio.txt |  55 ++++++++
 drivers/gpio/Kconfig                   |  10 ++
 drivers/gpio/gpio-uclass.c             | 181 ++++++++++++++++++++++---
 include/asm-generic/gpio.h             |  32 +++++
 5 files changed, 268 insertions(+), 16 deletions(-)

diff --git a/common/board_r.c b/common/board_r.c
index 472987d5d5..5bb8f88bd0 100644
--- a/common/board_r.c
+++ b/common/board_r.c
@@ -48,6 +48,9 @@
 #include <linux/compiler.h>
 #include <linux/err.h>
 #include <efi_loader.h>
+#if defined(CONFIG_DM_GPIO_HOG)
+#include <asm/gpio.h>
+#endif
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -785,6 +788,9 @@ static init_fnc_t init_sequence_r[] = {
 #ifdef CONFIG_CMD_NET
 	initr_ethaddr,
 #endif
+#if defined(CONFIG_DM_GPIO_HOG)
+	gpio_hog_probe_all,
+#endif
 #ifdef CONFIG_BOARD_LATE_INIT
 	board_late_init,
 #endif
diff --git a/doc/device-tree-bindings/gpio/gpio.txt b/doc/device-tree-bindings/gpio/gpio.txt
index f7a158d858..e774439369 100644
--- a/doc/device-tree-bindings/gpio/gpio.txt
+++ b/doc/device-tree-bindings/gpio/gpio.txt
@@ -210,3 +210,58 @@ Example 2:
 Here, three GPIO ranges are defined wrt. two pin controllers. pinctrl1 GPIO
 ranges are defined using pin numbers whereas the GPIO ranges wrt. pinctrl2
 are named "foo" and "bar".
+
+3) GPIO hog definitions
+-----------------------
+
+The GPIO chip may contain GPIO hog definitions. GPIO hogging is a mechanism
+providing automatic GPIO request and configuration as part of the
+gpio-controller's driver probe function.
+
+Each GPIO hog definition is represented as a child node of the GPIO controller.
+Required properties:
+- gpio-hog:   A property specifying that this child node represents a GPIO hog.
+- gpios:      Store the GPIO information (id, flags) for the GPIO to
+	      affect.
+
+              ! Not yet support more than one gpio !
+
+Only one of the following properties scanned in the order shown below.
+- input:      A property specifying to set the GPIO direction as input.
+- output-low  A property specifying to set the GPIO direction as output with
+	      the value low.
+- output-high A property specifying to set the GPIO direction as output with
+	      the value high.
+
+Optional properties:
+- line-name:  The GPIO label name. If not present the node name is used.
+
+Example:
+
+        tca6416@20 {
+                compatible = "ti,tca6416";
+                reg = <0x20>;
+                #gpio-cells = <2>;
+                gpio-controller;
+
+                env_reset {
+                        gpio-hog;
+                        input;
+                        gpios = <6 GPIO_ACTIVE_LOW>;
+                };
+                boot_rescue {
+                        gpio-hog;
+                        input;
+                        gpios = <7 GPIO_ACTIVE_LOW>;
+                };
+        };
+
+For the above Example you can than access the gpio in your boardcode
+with:
+
+        desc = gpio_hog_lookup_name("boot_rescue.gpio-hog");
+        if (desc) {
+                if (dm_gpio_get_value(desc))
+                        printf("\nBooting into Rescue System\n");
+		else
+			printf("\nBoot normal\n");
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index a519a0a169..56ed37c2b5 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -14,6 +14,16 @@ config DM_GPIO
 	  particular GPIOs that they provide. The uclass interface
 	  is defined in include/asm-generic/gpio.h.
 
+config DM_GPIO_HOG
+	bool "Enable GPIO hog support"
+	depends on DM_GPIO
+	default n
+	help
+	  Enable gpio hog support
+	  The GPIO chip may contain GPIO hog definitions. GPIO hogging
+	  is a mechanism providing automatic GPIO request and config-
+	  uration as part of the gpio-controller's driver probe function.
+
 config ALTERA_PIO
 	bool "Altera PIO driver"
 	depends on DM_GPIO
diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index da5e9ba6e5..308d0863ad 100644
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -5,6 +5,9 @@
 
 #include <common.h>
 #include <dm.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
+#include <dm/uclass-internal.h>
 #include <dt-bindings/gpio/gpio.h>
 #include <errno.h>
 #include <fdtdec.h>
@@ -141,6 +144,118 @@ static int gpio_find_and_xlate(struct gpio_desc *desc,
 		return gpio_xlate_offs_flags(desc->dev, desc, args);
 }
 
+#if defined(CONFIG_DM_GPIO_HOG)
+
+struct gpio_hog_priv {
+	struct gpio_desc gpiod;
+};
+
+struct gpio_hog_data {
+	int gpiod_flags;
+	int value;
+	u32 val[2];
+};
+
+static int gpio_hog_ofdata_to_platdata(struct udevice *dev)
+{
+	struct gpio_hog_data *plat = dev_get_platdata(dev);
+	const char *nodename;
+	int ret;
+
+	plat->value = 0;
+	if (dev_read_bool(dev, "input")) {
+		plat->gpiod_flags = GPIOD_IS_IN;
+	} else if (dev_read_bool(dev, "output-high")) {
+		plat->value = 1;
+		plat->gpiod_flags = GPIOD_IS_OUT;
+	} else if (dev_read_bool(dev, "output-low")) {
+		plat->gpiod_flags = GPIOD_IS_OUT;
+	} else {
+		printf("%s: missing gpio-hog state.\n", __func__);
+		return -EINVAL;
+	}
+	ret = dev_read_u32_array(dev, "gpios", plat->val, 2);
+	if (ret) {
+		printf("%s: wrong gpios property, 2 values needed %d\n",
+		       __func__, ret);
+		return ret;
+	}
+	nodename = dev_read_string(dev, "line-name");
+	if (!nodename)
+		nodename = dev_read_name(dev);
+	device_set_name(dev, nodename);
+
+	return 0;
+}
+
+static int gpio_hog_probe(struct udevice *dev)
+{
+	struct gpio_hog_data *plat = dev_get_platdata(dev);
+	struct gpio_hog_priv *priv = dev_get_priv(dev);
+	int ret;
+
+	ret = gpio_dev_request_index(dev->parent, dev->name, "gpio-hog",
+				     plat->val[0], plat->gpiod_flags,
+				     plat->val[1], &priv->gpiod);
+	if (ret < 0) {
+		debug("%s: node %s could not get gpio.\n", __func__,
+		      dev->name);
+		return ret;
+	}
+	dm_gpio_set_dir(&priv->gpiod);
+	if (plat->gpiod_flags == GPIOD_IS_OUT)
+		dm_gpio_set_value(&priv->gpiod, plat->value);
+
+	return 0;
+}
+
+int gpio_hog_probe_all(void)
+{
+	struct udevice *dev;
+	int ret;
+
+	for (uclass_first_device(UCLASS_NOP, &dev);
+	     dev;
+	     uclass_find_next_device(&dev)) {
+		if (dev->driver == DM_GET_DRIVER(gpio_hog)) {
+			ret = device_probe(dev);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+struct gpio_desc *gpio_hog_lookup_name(const char *name)
+{
+	struct udevice *dev;
+
+	gpio_hog_probe_all();
+	if (!uclass_get_device_by_name(UCLASS_NOP, name, &dev)) {
+		struct gpio_hog_priv *priv = dev_get_priv(dev);
+
+		return &priv->gpiod;
+	}
+
+	return NULL;
+}
+
+U_BOOT_DRIVER(gpio_hog) = {
+	.name	= "gpio_hog",
+	.id	= UCLASS_NOP,
+	.ofdata_to_platdata = gpio_hog_ofdata_to_platdata,
+	.probe = gpio_hog_probe,
+	.priv_auto_alloc_size = sizeof(struct gpio_hog_priv),
+	.platdata_auto_alloc_size = sizeof(struct gpio_hog_data),
+};
+#else
+struct gpio_desc *gpio_hog_lookup_name(const char *name)
+{
+	return NULL;
+}
+#endif
+
 int dm_gpio_request(struct gpio_desc *desc, const char *label)
 {
 	struct udevice *dev = desc->dev;
@@ -640,22 +755,25 @@ int dm_gpio_get_values_as_int(const struct gpio_desc *desc_list, int count)
 	return vector;
 }
 
-static int gpio_request_tail(int ret, ofnode node,
+static int gpio_request_tail(int ret, const char *nodename,
 			     struct ofnode_phandle_args *args,
 			     const char *list_name, int index,
-			     struct gpio_desc *desc, int flags, bool add_index)
+			     struct gpio_desc *desc, int flags,
+			     bool add_index, struct udevice *dev)
 {
-	desc->dev = NULL;
+	desc->dev = dev;
 	desc->offset = 0;
 	desc->flags = 0;
 	if (ret)
 		goto err;
 
-	ret = uclass_get_device_by_ofnode(UCLASS_GPIO, args->node,
-					  &desc->dev);
-	if (ret) {
-		debug("%s: uclass_get_device_by_ofnode failed\n", __func__);
-		goto err;
+	if (!desc->dev) {
+		ret = uclass_get_device_by_ofnode(UCLASS_GPIO, args->node,
+						  &desc->dev);
+		if (ret) {
+			debug("%s: uclass_get_device_by_ofnode failed\n", __func__);
+			goto err;
+		}
 	}
 	ret = gpio_find_and_xlate(desc, args);
 	if (ret) {
@@ -663,8 +781,7 @@ static int gpio_request_tail(int ret, ofnode node,
 		goto err;
 	}
 	ret = dm_gpio_requestf(desc, add_index ? "%s.%s%d" : "%s.%s",
-			       ofnode_get_name(node),
-			       list_name, index);
+			       nodename, list_name, index);
 	if (ret) {
 		debug("%s: dm_gpio_requestf failed\n", __func__);
 		goto err;
@@ -678,7 +795,7 @@ static int gpio_request_tail(int ret, ofnode node,
 	return 0;
 err:
 	debug("%s: Node '%s', property '%s', failed to request GPIO index %d: %d\n",
-	      __func__, ofnode_get_name(node), list_name, index, ret);
+	      __func__, nodename, list_name, index, ret);
 	return ret;
 }
 
@@ -692,8 +809,8 @@ static int _gpio_request_by_name_nodev(ofnode node, const char *list_name,
 	ret = ofnode_parse_phandle_with_args(node, list_name, "#gpio-cells", 0,
 					     index, &args);
 
-	return gpio_request_tail(ret, node, &args, list_name, index, desc,
-				 flags, add_index);
+	return gpio_request_tail(ret, ofnode_get_name(node), &args, list_name,
+				 index, desc, flags, add_index, NULL);
 }
 
 int gpio_request_by_name_nodev(ofnode node, const char *list_name, int index,
@@ -707,13 +824,14 @@ int gpio_request_by_name(struct udevice *dev, const char *list_name, int index,
 			 struct gpio_desc *desc, int flags)
 {
 	struct ofnode_phandle_args args;
+	ofnode node;
 	int ret;
 
 	ret = dev_read_phandle_with_args(dev, list_name, "#gpio-cells", 0,
 					 index, &args);
-
-	return gpio_request_tail(ret, dev_ofnode(dev), &args, list_name,
-				 index, desc, flags, index > 0);
+	node = dev_ofnode(dev);
+	return gpio_request_tail(ret, ofnode_get_name(node), &args, list_name,
+				 index, desc, flags, index > 0, NULL);
 }
 
 int gpio_request_list_by_name_nodev(ofnode node, const char *list_name,
@@ -854,8 +972,28 @@ static int gpio_pre_remove(struct udevice *dev)
 	return gpio_renumber(dev);
 }
 
+int gpio_dev_request_index(struct udevice *dev, const char *nodename,
+			   char *list_name, int index, int flags,
+			   int dtflags, struct gpio_desc *desc)
+{
+	struct ofnode_phandle_args args;
+
+	args.node =  ofnode_null();
+	args.args_count = 2;
+	args.args[0] = index;
+	args.args[1] = dtflags;
+
+	return gpio_request_tail(0, nodename, &args, list_name, index, desc,
+				 flags, 0, dev);
+}
+
 static int gpio_post_bind(struct udevice *dev)
 {
+#if defined(CONFIG_DM_GPIO_HOG)
+	struct udevice *child;
+	ofnode node;
+#endif
+
 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
 	struct dm_gpio_ops *ops = (struct dm_gpio_ops *)device_get_ops(dev);
 	static int reloc_done;
@@ -885,6 +1023,17 @@ static int gpio_post_bind(struct udevice *dev)
 		reloc_done++;
 	}
 #endif
+
+#if defined(CONFIG_DM_GPIO_HOG)
+	dev_for_each_subnode(node, dev) {
+		if (ofnode_read_bool(node, "gpio-hog")) {
+			const char *name = ofnode_get_name(node);
+
+			device_bind_driver_to_node(dev, "gpio_hog", name,
+						   node, &child);
+		}
+	}
+#endif
 	return 0;
 }
 
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index d03602696f..37f71e5708 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -348,6 +348,22 @@ const char *gpio_get_bank_info(struct udevice *dev, int *offset_count);
  */
 int dm_gpio_lookup_name(const char *name, struct gpio_desc *desc);
 
+/**
+ * gpio_hog_lookup_name() - Look up a named GPIO and return the gpio descr.
+ *
+ * @name:	Name to look up
+ * @return:	Returns gpio_desc for gpio
+ */
+struct gpio_desc *gpio_hog_lookup_name(const char *name);
+
+/**
+ * gpio_hog_probe_all() - probe all gpio devices with
+ * gpio-hog subnodes.
+ *
+ * @return:	Returns return value from device_probe()
+ */
+int gpio_hog_probe_all(void);
+
 /**
  * gpio_lookup_name - Look up a GPIO name and return its details
  *
@@ -503,6 +519,22 @@ int gpio_request_list_by_name_nodev(ofnode node, const char *list_name,
 				    struct gpio_desc *desc_list, int max_count,
 				    int flags);
 
+/**
+ * gpio_dev_request_index() - request single GPIO from gpio device
+ *
+ * @dev:	GPIO device
+ * @nodename:	Name of node
+ * @list_name:	Name of GPIO list (e.g. "board-id-gpios")
+ * @index:	Index number of the GPIO in that list use request (0=first)
+ * @flags:	GPIOD_* flags
+ * @dtflags:	GPIO flags read from DT
+ * @desc:	GPIO descriotor filled from this function
+ * @return:	return value from gpio_request_tail()
+ */
+int gpio_dev_request_index(struct udevice *dev, const char *nodename,
+			   char *list_name, int index, int flags,
+			   int dtflags, struct gpio_desc *desc);
+
 /**
  * dm_gpio_free() - Free a single GPIO
  *
-- 
2.27.0

Re: [PATCH U-Boot v2019.04-aspeed-openbmc 2/6] gpio: add gpio-hog support

[Andrew Jeffery]

On Tue, 25 Jan 2022, at 05:44, Eddie James wrote:
> From: Heiko Schocher <hs@denx.de>
>
> add gpio-hog support. GPIO hogging is a mechanism
> providing automatic GPIO request and configuration
> as part of the gpio-controller's driver probe function.
>
> for more infos see:
> doc/device-tree-bindings/gpio/gpio.txt
>

(cherry-picked from 5fc7cf8c8e268590f3b0037eecea7f6798209f78) ?

> Signed-off-by: Heiko Schocher <hs@denx.de>
> Tested-by: Michal Simek <michal.simek@xilinx.com> (zcu102)
> Tested-by: Patrick Delaunay <patrick.delaunay@st.com>

[PATCH U-Boot v2019.04-aspeed-openbmc 3/6] gpio: fixes for gpio-hog support

[Eddie James]

From: Heiko Schocher <hs@denx.de>

recently added gpio hog patch was "in discussion"
state with Simon Glass. This patch now adds most
of comments from Simon Glass.

Signed-off-by: Heiko Schocher <hs@denx.de>
---
 common/board_r.c                       |   4 +-
 doc/device-tree-bindings/gpio/gpio.txt |  17 ++--
 drivers/gpio/Kconfig                   |   2 +-
 drivers/gpio/gpio-uclass.c             | 103 ++++++++++++++++++-------
 include/asm-generic/gpio.h             |  12 +--
 5 files changed, 96 insertions(+), 42 deletions(-)

diff --git a/common/board_r.c b/common/board_r.c
index 5bb8f88bd0..429b9a2833 100644
--- a/common/board_r.c
+++ b/common/board_r.c
@@ -48,7 +48,7 @@
 #include <linux/compiler.h>
 #include <linux/err.h>
 #include <efi_loader.h>
-#if defined(CONFIG_DM_GPIO_HOG)
+#if defined(CONFIG_GPIO_HOG)
 #include <asm/gpio.h>
 #endif
 
@@ -788,7 +788,7 @@ static init_fnc_t init_sequence_r[] = {
 #ifdef CONFIG_CMD_NET
 	initr_ethaddr,
 #endif
-#if defined(CONFIG_DM_GPIO_HOG)
+#if defined(CONFIG_GPIO_HOG)
 	gpio_hog_probe_all,
 #endif
 #ifdef CONFIG_BOARD_LATE_INIT
diff --git a/doc/device-tree-bindings/gpio/gpio.txt b/doc/device-tree-bindings/gpio/gpio.txt
index e774439369..e146917ff3 100644
--- a/doc/device-tree-bindings/gpio/gpio.txt
+++ b/doc/device-tree-bindings/gpio/gpio.txt
@@ -252,6 +252,7 @@ Example:
                 boot_rescue {
                         gpio-hog;
                         input;
+                        line-name = "foo-bar-gpio";
                         gpios = <7 GPIO_ACTIVE_LOW>;
                 };
         };
@@ -259,9 +260,13 @@ Example:
 For the above Example you can than access the gpio in your boardcode
 with:
 
-        desc = gpio_hog_lookup_name("boot_rescue.gpio-hog");
-        if (desc) {
-                if (dm_gpio_get_value(desc))
-                        printf("\nBooting into Rescue System\n");
-		else
-			printf("\nBoot normal\n");
+	struct gpio_desc *desc;
+	int ret;
+
+	ret = gpio_hog_lookup_name("boot_rescue", &desc);
+	if (ret)
+		return;
+	if (dm_gpio_get_value(desc) == 1)
+		printf("\nBooting into Rescue System\n");
+	else if (dm_gpio_get_value(desc) == 0)
+		printf("\nBoot normal\n");
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 56ed37c2b5..a8dc16ca0e 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -14,7 +14,7 @@ config DM_GPIO
 	  particular GPIOs that they provide. The uclass interface
 	  is defined in include/asm-generic/gpio.h.
 
-config DM_GPIO_HOG
+config GPIO_HOG
 	bool "Enable GPIO hog support"
 	depends on DM_GPIO
 	default n
diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index 308d0863ad..01cfa2f788 100644
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -144,7 +144,7 @@ static int gpio_find_and_xlate(struct gpio_desc *desc,
 		return gpio_xlate_offs_flags(desc->dev, desc, args);
 }
 
-#if defined(CONFIG_DM_GPIO_HOG)
+#if defined(CONFIG_GPIO_HOG)
 
 struct gpio_hog_priv {
 	struct gpio_desc gpiod;
@@ -181,9 +181,8 @@ static int gpio_hog_ofdata_to_platdata(struct udevice *dev)
 		return ret;
 	}
 	nodename = dev_read_string(dev, "line-name");
-	if (!nodename)
-		nodename = dev_read_name(dev);
-	device_set_name(dev, nodename);
+	if (nodename)
+		device_set_name(dev, nodename);
 
 	return 0;
 }
@@ -202,9 +201,15 @@ static int gpio_hog_probe(struct udevice *dev)
 		      dev->name);
 		return ret;
 	}
-	dm_gpio_set_dir(&priv->gpiod);
-	if (plat->gpiod_flags == GPIOD_IS_OUT)
-		dm_gpio_set_value(&priv->gpiod, plat->value);
+
+	if (plat->gpiod_flags == GPIOD_IS_OUT) {
+		ret = dm_gpio_set_value(&priv->gpiod, plat->value);
+		if (ret < 0) {
+			debug("%s: node %s could not set gpio.\n", __func__,
+			      dev->name);
+			return ret;
+		}
+	}
 
 	return 0;
 }
@@ -213,32 +218,38 @@ int gpio_hog_probe_all(void)
 {
 	struct udevice *dev;
 	int ret;
+	int retval = 0;
 
 	for (uclass_first_device(UCLASS_NOP, &dev);
 	     dev;
 	     uclass_find_next_device(&dev)) {
 		if (dev->driver == DM_GET_DRIVER(gpio_hog)) {
 			ret = device_probe(dev);
-			if (ret)
-				return ret;
+			if (ret) {
+				printf("Failed to probe device %s err: %d\n",
+				       dev->name, ret);
+				retval = ret;
+			}
 		}
 	}
 
-	return 0;
+	return retval;
 }
 
-struct gpio_desc *gpio_hog_lookup_name(const char *name)
+int gpio_hog_lookup_name(const char *name, struct gpio_desc **desc)
 {
 	struct udevice *dev;
 
+	*desc = NULL;
 	gpio_hog_probe_all();
 	if (!uclass_get_device_by_name(UCLASS_NOP, name, &dev)) {
 		struct gpio_hog_priv *priv = dev_get_priv(dev);
 
-		return &priv->gpiod;
+		*desc = &priv->gpiod;
+		return 0;
 	}
 
-	return NULL;
+	return -ENODEV;
 }
 
 U_BOOT_DRIVER(gpio_hog) = {
@@ -250,9 +261,9 @@ U_BOOT_DRIVER(gpio_hog) = {
 	.platdata_auto_alloc_size = sizeof(struct gpio_hog_data),
 };
 #else
-struct gpio_desc *gpio_hog_lookup_name(const char *name)
+int gpio_hog_lookup_name(const char *name, struct gpio_desc **desc)
 {
-	return NULL;
+	return 0;
 }
 #endif
 
@@ -755,13 +766,45 @@ int dm_gpio_get_values_as_int(const struct gpio_desc *desc_list, int count)
 	return vector;
 }
 
+/**
+ * gpio_request_tail: common work for requesting a gpio.
+ *
+ * ret:		return value from previous work in function which calls
+ *		this function.
+ *		This seems bogus (why calling this function instead not
+ *		calling it and end caller function instead?).
+ *		Because on error in caller function we want to set some
+ *		default values in gpio desc and have a common error
+ *		debug message, which provides this function.
+ * nodename:	Name of node for which gpio gets requested
+ *		used for gpio label name.
+ * args:	pointer to output arguments structure
+ * list_name:	Name of GPIO list
+ *		used for gpio label name.
+ * index:	gpio index in gpio list
+ *		used for gpio label name.
+ * desc:	pointer to gpio descriptor, filled from this
+ *		function.
+ * flags:	gpio flags to use.
+ * add_index:	should index added to gpio label name
+ * gpio_dev:	pointer to gpio device from which the gpio
+ *		will be requested. If NULL try to get the
+ *		gpio device with uclass_get_device_by_ofnode()
+ *
+ * return:	In error case this function sets default values in
+ *		gpio descriptor, also emmits a debug message.
+ *		On success it returns 0 else the error code from
+ *		function calls, or the error code passed through
+ *		ret to this function.
+ *
+ */
 static int gpio_request_tail(int ret, const char *nodename,
 			     struct ofnode_phandle_args *args,
 			     const char *list_name, int index,
 			     struct gpio_desc *desc, int flags,
-			     bool add_index, struct udevice *dev)
+			     bool add_index, struct udevice *gpio_dev)
 {
-	desc->dev = dev;
+	desc->dev = gpio_dev;
 	desc->offset = 0;
 	desc->flags = 0;
 	if (ret)
@@ -771,7 +814,8 @@ static int gpio_request_tail(int ret, const char *nodename,
 		ret = uclass_get_device_by_ofnode(UCLASS_GPIO, args->node,
 						  &desc->dev);
 		if (ret) {
-			debug("%s: uclass_get_device_by_ofnode failed\n", __func__);
+			debug("%s: uclass_get_device_by_ofnode failed\n",
+			      __func__);
 			goto err;
 		}
 	}
@@ -989,10 +1033,8 @@ int gpio_dev_request_index(struct udevice *dev, const char *nodename,
 
 static int gpio_post_bind(struct udevice *dev)
 {
-#if defined(CONFIG_DM_GPIO_HOG)
 	struct udevice *child;
 	ofnode node;
-#endif
 
 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
 	struct dm_gpio_ops *ops = (struct dm_gpio_ops *)device_get_ops(dev);
@@ -1024,16 +1066,21 @@ static int gpio_post_bind(struct udevice *dev)
 	}
 #endif
 
-#if defined(CONFIG_DM_GPIO_HOG)
-	dev_for_each_subnode(node, dev) {
-		if (ofnode_read_bool(node, "gpio-hog")) {
-			const char *name = ofnode_get_name(node);
-
-			device_bind_driver_to_node(dev, "gpio_hog", name,
-						   node, &child);
+	if (IS_ENABLED(CONFIG_GPIO_HOG)) {
+		dev_for_each_subnode(node, dev) {
+			if (ofnode_read_bool(node, "gpio-hog")) {
+				const char *name = ofnode_get_name(node);
+				int ret;
+
+				ret = device_bind_driver_to_node(dev,
+								 "gpio_hog",
+								 name, node,
+								 &child);
+				if (ret)
+					return ret;
+			}
 		}
 	}
-#endif
 	return 0;
 }
 
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index 37f71e5708..d6cf18744f 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -352,9 +352,10 @@ int dm_gpio_lookup_name(const char *name, struct gpio_desc *desc);
  * gpio_hog_lookup_name() - Look up a named GPIO and return the gpio descr.
  *
  * @name:	Name to look up
- * @return:	Returns gpio_desc for gpio
+ * @desc:	Returns GPIO description, on success, else NULL
+ * @return:	Returns 0 if OK, else -ENODEV
  */
-struct gpio_desc *gpio_hog_lookup_name(const char *name);
+int gpio_hog_lookup_name(const char *name, struct gpio_desc **desc);
 
 /**
  * gpio_hog_probe_all() - probe all gpio devices with
@@ -523,12 +524,13 @@ int gpio_request_list_by_name_nodev(ofnode node, const char *list_name,
  * gpio_dev_request_index() - request single GPIO from gpio device
  *
  * @dev:	GPIO device
- * @nodename:	Name of node
+ * @nodename:	Name of node for which gpio gets requested, used
+ *		for the gpio label name
  * @list_name:	Name of GPIO list (e.g. "board-id-gpios")
  * @index:	Index number of the GPIO in that list use request (0=first)
  * @flags:	GPIOD_* flags
- * @dtflags:	GPIO flags read from DT
- * @desc:	GPIO descriotor filled from this function
+ * @dtflags:	GPIO flags read from DT defined see GPIOD_*
+ * @desc:	returns GPIO descriptor filled from this function
  * @return:	return value from gpio_request_tail()
  */
 int gpio_dev_request_index(struct udevice *dev, const char *nodename,
-- 
2.27.0

Re: [PATCH U-Boot v2019.04-aspeed-openbmc 3/6] gpio: fixes for gpio-hog support

[Andrew Jeffery]

On Tue, 25 Jan 2022, at 05:45, Eddie James wrote:
> From: Heiko Schocher <hs@denx.de>
>
> recently added gpio hog patch was "in discussion"
> state with Simon Glass. This patch now adds most
> of comments from Simon Glass.
>
> Signed-off-by: Heiko Schocher <hs@denx.de>

Cherry-picked from 49b10cb4926285b856b207c1f5bb40c75487f08b ?

[PATCH U-Boot v2019.04-aspeed-openbmc 4/6] gpio: Enable hogging support in SPL

[Eddie James]

Use the CONFIG macros to conditionally build the GPIO hogging support in
either the SPL or U-Boot, or both, depending on the configuration. Also
call the GPIO hog probe function in the common SPL board initialization
as an equivalent to adding it to the U-Boot init sequence functions.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 common/spl/spl.c           |  7 +++++++
 drivers/gpio/Kconfig       | 10 ++++++++++
 drivers/gpio/gpio-uclass.c | 12 +++++++-----
 3 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/common/spl/spl.c b/common/spl/spl.c
index a1d4514fd3..bbb7578463 100644
--- a/common/spl/spl.c
+++ b/common/spl/spl.c
@@ -12,6 +12,9 @@
 #include <dm.h>
 #include <handoff.h>
 #include <spl.h>
+#if defined(CONFIG_SPL_GPIO_HOG)
+#include <asm/gpio.h>
+#endif
 #include <asm/sections.h>
 #include <asm/u-boot.h>
 #include <nand.h>
@@ -652,6 +655,10 @@ void board_init_r(gd_t *dummy1, ulong dummy2)
 	timer_init();
 #endif
 
+#if defined(CONFIG_SPL_GPIO_HOG)
+	gpio_hog_probe_all();
+#endif
+
 #if CONFIG_IS_ENABLED(BOARD_INIT)
 	spl_board_init();
 #endif
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index a8dc16ca0e..8b8bf6822f 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -24,6 +24,16 @@ config GPIO_HOG
 	  is a mechanism providing automatic GPIO request and config-
 	  uration as part of the gpio-controller's driver probe function.
 
+config SPL_GPIO_HOG
+	bool "Enable GPIO hog support in SPL"
+	depends on SPL_GPIO_SUPPORT
+	default n
+	help
+	  Enable gpio hog support
+	  The GPIO chip may contain GPIO hog definitions. GPIO hogging
+	  is a mechanism providing automatic GPIO request and config-
+	  uration as part of the gpio-controller's driver probe function.
+
 config ALTERA_PIO
 	bool "Altera PIO driver"
 	depends on DM_GPIO
diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index 01cfa2f788..219caa651b 100644
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -144,7 +144,7 @@ static int gpio_find_and_xlate(struct gpio_desc *desc,
 		return gpio_xlate_offs_flags(desc->dev, desc, args);
 }
 
-#if defined(CONFIG_GPIO_HOG)
+#if CONFIG_IS_ENABLED(GPIO_HOG)
 
 struct gpio_hog_priv {
 	struct gpio_desc gpiod;
@@ -1033,9 +1033,6 @@ int gpio_dev_request_index(struct udevice *dev, const char *nodename,
 
 static int gpio_post_bind(struct udevice *dev)
 {
-	struct udevice *child;
-	ofnode node;
-
 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
 	struct dm_gpio_ops *ops = (struct dm_gpio_ops *)device_get_ops(dev);
 	static int reloc_done;
@@ -1066,7 +1063,11 @@ static int gpio_post_bind(struct udevice *dev)
 	}
 #endif
 
-	if (IS_ENABLED(CONFIG_GPIO_HOG)) {
+#if CONFIG_IS_ENABLED(GPIO_HOG)
+	{
+		struct udevice *child;
+		ofnode node;
+
 		dev_for_each_subnode(node, dev) {
 			if (ofnode_read_bool(node, "gpio-hog")) {
 				const char *name = ofnode_get_name(node);
@@ -1081,6 +1082,7 @@ static int gpio_post_bind(struct udevice *dev)
 			}
 		}
 	}
+#endif
 	return 0;
 }
 
-- 
2.27.0

Re: [PATCH U-Boot v2019.04-aspeed-openbmc 4/6] gpio: Enable hogging support in SPL

[Andrew Jeffery]

On Tue, 25 Jan 2022, at 05:45, Eddie James wrote:
> Use the CONFIG macros to conditionally build the GPIO hogging support in
> either the SPL or U-Boot, or both, depending on the configuration. Also
> call the GPIO hog probe function in the common SPL board initialization
> as an equivalent to adding it to the U-Boot init sequence functions.
>
> Signed-off-by: Eddie James <eajames@linux.ibm.com>
> ---
>  common/spl/spl.c           |  7 +++++++
>  drivers/gpio/Kconfig       | 10 ++++++++++
>  drivers/gpio/gpio-uclass.c | 12 +++++++-----
>  3 files changed, 24 insertions(+), 5 deletions(-)
>
> diff --git a/common/spl/spl.c b/common/spl/spl.c
> index a1d4514fd3..bbb7578463 100644
> --- a/common/spl/spl.c
> +++ b/common/spl/spl.c
> @@ -12,6 +12,9 @@
>  #include <dm.h>
>  #include <handoff.h>
>  #include <spl.h>
> +#if defined(CONFIG_SPL_GPIO_HOG)
> +#include <asm/gpio.h>
> +#endif
>  #include <asm/sections.h>
>  #include <asm/u-boot.h>
>  #include <nand.h>
> @@ -652,6 +655,10 @@ void board_init_r(gd_t *dummy1, ulong dummy2)
>  	timer_init();
>  #endif
> 
> +#if defined(CONFIG_SPL_GPIO_HOG)
> +	gpio_hog_probe_all();
> +#endif
> +
>  #if CONFIG_IS_ENABLED(BOARD_INIT)
>  	spl_board_init();
>  #endif
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index a8dc16ca0e..8b8bf6822f 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -24,6 +24,16 @@ config GPIO_HOG
>  	  is a mechanism providing automatic GPIO request and config-
>  	  uration as part of the gpio-controller's driver probe function.
> 
> +config SPL_GPIO_HOG
> +	bool "Enable GPIO hog support in SPL"
> +	depends on SPL_GPIO_SUPPORT
> +	default n
> +	help
> +	  Enable gpio hog support
> +	  The GPIO chip may contain GPIO hog definitions. GPIO hogging
> +	  is a mechanism providing automatic GPIO request and config-
> +	  uration as part of the gpio-controller's driver probe function.
> +
>  config ALTERA_PIO
>  	bool "Altera PIO driver"
>  	depends on DM_GPIO
> diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
> index 01cfa2f788..219caa651b 100644
> --- a/drivers/gpio/gpio-uclass.c
> +++ b/drivers/gpio/gpio-uclass.c
> @@ -144,7 +144,7 @@ static int gpio_find_and_xlate(struct gpio_desc *desc,
>  		return gpio_xlate_offs_flags(desc->dev, desc, args);
>  }
> 
> -#if defined(CONFIG_GPIO_HOG)
> +#if CONFIG_IS_ENABLED(GPIO_HOG)
> 
>  struct gpio_hog_priv {
>  	struct gpio_desc gpiod;
> @@ -1033,9 +1033,6 @@ int gpio_dev_request_index(struct udevice *dev, 
> const char *nodename,
> 
>  static int gpio_post_bind(struct udevice *dev)
>  {
> -	struct udevice *child;
> -	ofnode node;
> -
>  #if defined(CONFIG_NEEDS_MANUAL_RELOC)
>  	struct dm_gpio_ops *ops = (struct dm_gpio_ops *)device_get_ops(dev);
>  	static int reloc_done;
> @@ -1066,7 +1063,11 @@ static int gpio_post_bind(struct udevice *dev)
>  	}
>  #endif
> 
> -	if (IS_ENABLED(CONFIG_GPIO_HOG)) {
> +#if CONFIG_IS_ENABLED(GPIO_HOG)

Why switch to a CPP conditional here?

I mean, it's not clear why there was a choice for a C conditional 
originally, so I'm curious either way.

Otherwise:

Reviewed-by: Andrew Jeffery <andrew@aj.id.au>

Re: [PATCH U-Boot v2019.04-aspeed-openbmc 4/6] gpio: Enable hogging support in SPL

[Eddie James]

On 2/2/22 20:11, Andrew Jeffery wrote:
>
> On Tue, 25 Jan 2022, at 05:45, Eddie James wrote:
>> Use the CONFIG macros to conditionally build the GPIO hogging support in
>> either the SPL or U-Boot, or both, depending on the configuration. Also
>> call the GPIO hog probe function in the common SPL board initialization
>> as an equivalent to adding it to the U-Boot init sequence functions.
>>
>> Signed-off-by: Eddie James <eajames@linux.ibm.com>
>> ---
>>   common/spl/spl.c           |  7 +++++++
>>   drivers/gpio/Kconfig       | 10 ++++++++++
>>   drivers/gpio/gpio-uclass.c | 12 +++++++-----
>>   3 files changed, 24 insertions(+), 5 deletions(-)
>>
>> diff --git a/common/spl/spl.c b/common/spl/spl.c
>> index a1d4514fd3..bbb7578463 100644
>> --- a/common/spl/spl.c
>> +++ b/common/spl/spl.c
>> @@ -12,6 +12,9 @@
>>   #include <dm.h>
>>   #include <handoff.h>
>>   #include <spl.h>
>> +#if defined(CONFIG_SPL_GPIO_HOG)
>> +#include <asm/gpio.h>
>> +#endif
>>   #include <asm/sections.h>
>>   #include <asm/u-boot.h>
>>   #include <nand.h>
>> @@ -652,6 +655,10 @@ void board_init_r(gd_t *dummy1, ulong dummy2)
>>   	timer_init();
>>   #endif
>>
>> +#if defined(CONFIG_SPL_GPIO_HOG)
>> +	gpio_hog_probe_all();
>> +#endif
>> +
>>   #if CONFIG_IS_ENABLED(BOARD_INIT)
>>   	spl_board_init();
>>   #endif
>> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
>> index a8dc16ca0e..8b8bf6822f 100644
>> --- a/drivers/gpio/Kconfig
>> +++ b/drivers/gpio/Kconfig
>> @@ -24,6 +24,16 @@ config GPIO_HOG
>>   	  is a mechanism providing automatic GPIO request and config-
>>   	  uration as part of the gpio-controller's driver probe function.
>>
>> +config SPL_GPIO_HOG
>> +	bool "Enable GPIO hog support in SPL"
>> +	depends on SPL_GPIO_SUPPORT
>> +	default n
>> +	help
>> +	  Enable gpio hog support
>> +	  The GPIO chip may contain GPIO hog definitions. GPIO hogging
>> +	  is a mechanism providing automatic GPIO request and config-
>> +	  uration as part of the gpio-controller's driver probe function.
>> +
>>   config ALTERA_PIO
>>   	bool "Altera PIO driver"
>>   	depends on DM_GPIO
>> diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
>> index 01cfa2f788..219caa651b 100644
>> --- a/drivers/gpio/gpio-uclass.c
>> +++ b/drivers/gpio/gpio-uclass.c
>> @@ -144,7 +144,7 @@ static int gpio_find_and_xlate(struct gpio_desc *desc,
>>   		return gpio_xlate_offs_flags(desc->dev, desc, args);
>>   }
>>
>> -#if defined(CONFIG_GPIO_HOG)
>> +#if CONFIG_IS_ENABLED(GPIO_HOG)
>>
>>   struct gpio_hog_priv {
>>   	struct gpio_desc gpiod;
>> @@ -1033,9 +1033,6 @@ int gpio_dev_request_index(struct udevice *dev,
>> const char *nodename,
>>
>>   static int gpio_post_bind(struct udevice *dev)
>>   {
>> -	struct udevice *child;
>> -	ofnode node;
>> -
>>   #if defined(CONFIG_NEEDS_MANUAL_RELOC)
>>   	struct dm_gpio_ops *ops = (struct dm_gpio_ops *)device_get_ops(dev);
>>   	static int reloc_done;
>> @@ -1066,7 +1063,11 @@ static int gpio_post_bind(struct udevice *dev)
>>   	}
>>   #endif
>>
>> -	if (IS_ENABLED(CONFIG_GPIO_HOG)) {
>> +#if CONFIG_IS_ENABLED(GPIO_HOG)
> Why switch to a CPP conditional here?
>
> I mean, it's not clear why there was a choice for a C conditional
> originally, so I'm curious either way.


Well I just thought it should match the other conditionals for GPIO_HOG, 
and it's obviously more efficient at runtime. Other than that, no reason 
really.


Thanks!

Eddie


>
> Otherwise:
>
> Reviewed-by: Andrew Jeffery <andrew@aj.id.au>

Re: [PATCH U-Boot v2019.04-aspeed-openbmc 4/6] gpio: Enable hogging support in SPL

[Andrew Jeffery]

On Fri, 4 Feb 2022, at 02:17, Eddie James wrote:
> On 2/2/22 20:11, Andrew Jeffery wrote:
>>
>> On Tue, 25 Jan 2022, at 05:45, Eddie James wrote:
>>> -	if (IS_ENABLED(CONFIG_GPIO_HOG)) {
>>> +#if CONFIG_IS_ENABLED(GPIO_HOG)
>> Why switch to a CPP conditional here?
>>
>> I mean, it's not clear why there was a choice for a C conditional
>> originally, so I'm curious either way.
>
>
> Well I just thought it should match the other conditionals for GPIO_HOG, 
> and it's obviously more efficient at runtime. Other than that, no reason 
> really.

Well, I expect it will be optimised out in the C case anyway.

Doesn't matter too much.

Andrew

[PATCH U-Boot v2019.04-aspeed-openbmc 5/6] Add GPIO hogging support for AST2600 openbmc config

[Eddie James]

Enable GPIO support in the SPL and hog the GPIOs in the SPL only. Also
increase the size of the malloc size in the SPL to get the GPIO driver
loaded.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 configs/ast2600_openbmc_spl_emmc_defconfig | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/configs/ast2600_openbmc_spl_emmc_defconfig b/configs/ast2600_openbmc_spl_emmc_defconfig
index 344a4d8f9c..5f50298a58 100644
--- a/configs/ast2600_openbmc_spl_emmc_defconfig
+++ b/configs/ast2600_openbmc_spl_emmc_defconfig
@@ -11,6 +11,7 @@ CONFIG_SYS_TEXT_BASE=0x81000000
 CONFIG_ASPEED_AST2600=y
 # CONFIG_ASPEED_LOADERS is not set
 CONFIG_TARGET_EVB_AST2600A1=y
+CONFIG_SPL_GPIO_SUPPORT=y
 CONFIG_SPL_LIBCOMMON_SUPPORT=y
 CONFIG_SPL_LIBGENERIC_SUPPORT=y
 CONFIG_SYS_MALLOC_F_LEN=0x2000
@@ -19,7 +20,7 @@ CONFIG_SPL_SERIAL_SUPPORT=y
 CONFIG_SPL_DRIVERS_MISC_SUPPORT=y
 CONFIG_ENV_SIZE=0x10000
 CONFIG_ENV_OFFSET=0x5000
-CONFIG_SPL_SYS_MALLOC_F_LEN=0x800
+CONFIG_SPL_SYS_MALLOC_F_LEN=0x1000
 CONFIG_SPL=y
 CONFIG_SPL_STACK_R_ADDR=0x90300000
 CONFIG_ARMV7_BOOT_SEC_DEFAULT=y
@@ -94,6 +95,7 @@ CONFIG_CLK=y
 CONFIG_SPL_CLK=y
 CONFIG_ASPEED_HACE=y
 CONFIG_DM_GPIO=y
+CONFIG_SPL_GPIO_HOG=y
 CONFIG_ASPEED_GPIO=y
 CONFIG_DM_I2C=y
 CONFIG_SYS_I2C_ASPEED=y
-- 
2.27.0

Re: [PATCH U-Boot v2019.04-aspeed-openbmc 5/6] Add GPIO hogging support for AST2600 openbmc config

[Andrew Jeffery]

On Tue, 25 Jan 2022, at 05:45, Eddie James wrote:
> Enable GPIO support in the SPL and hog the GPIOs in the SPL only. Also
> increase the size of the malloc size in the SPL to get the GPIO driver
> loaded.
>
> Signed-off-by: Eddie James <eajames@linux.ibm.com>
> ---
>  configs/ast2600_openbmc_spl_emmc_defconfig | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/configs/ast2600_openbmc_spl_emmc_defconfig 
> b/configs/ast2600_openbmc_spl_emmc_defconfig
> index 344a4d8f9c..5f50298a58 100644
> --- a/configs/ast2600_openbmc_spl_emmc_defconfig
> +++ b/configs/ast2600_openbmc_spl_emmc_defconfig
> @@ -11,6 +11,7 @@ CONFIG_SYS_TEXT_BASE=0x81000000
>  CONFIG_ASPEED_AST2600=y
>  # CONFIG_ASPEED_LOADERS is not set
>  CONFIG_TARGET_EVB_AST2600A1=y
> +CONFIG_SPL_GPIO_SUPPORT=y
>  CONFIG_SPL_LIBCOMMON_SUPPORT=y
>  CONFIG_SPL_LIBGENERIC_SUPPORT=y
>  CONFIG_SYS_MALLOC_F_LEN=0x2000
> @@ -19,7 +20,7 @@ CONFIG_SPL_SERIAL_SUPPORT=y
>  CONFIG_SPL_DRIVERS_MISC_SUPPORT=y
>  CONFIG_ENV_SIZE=0x10000
>  CONFIG_ENV_OFFSET=0x5000
> -CONFIG_SPL_SYS_MALLOC_F_LEN=0x800
> +CONFIG_SPL_SYS_MALLOC_F_LEN=0x1000

How much capacity does this leave us with? Have you looked at the 
memory layout for the SPL (I haven't, so any legwork you do here is 
appreciated ;) )?

>  CONFIG_SPL=y
>  CONFIG_SPL_STACK_R_ADDR=0x90300000
>  CONFIG_ARMV7_BOOT_SEC_DEFAULT=y
> @@ -94,6 +95,7 @@ CONFIG_CLK=y
>  CONFIG_SPL_CLK=y
>  CONFIG_ASPEED_HACE=y
>  CONFIG_DM_GPIO=y
> +CONFIG_SPL_GPIO_HOG=y
>  CONFIG_ASPEED_GPIO=y
>  CONFIG_DM_I2C=y
>  CONFIG_SYS_I2C_ASPEED=y
> -- 
> 2.27.0

Re: [PATCH U-Boot v2019.04-aspeed-openbmc 5/6] Add GPIO hogging support for AST2600 openbmc config

[Eddie James]

On 2/2/22 20:13, Andrew Jeffery wrote:
>
> On Tue, 25 Jan 2022, at 05:45, Eddie James wrote:
>> Enable GPIO support in the SPL and hog the GPIOs in the SPL only. Also
>> increase the size of the malloc size in the SPL to get the GPIO driver
>> loaded.
>>
>> Signed-off-by: Eddie James <eajames@linux.ibm.com>
>> ---
>>   configs/ast2600_openbmc_spl_emmc_defconfig | 4 +++-
>>   1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/configs/ast2600_openbmc_spl_emmc_defconfig
>> b/configs/ast2600_openbmc_spl_emmc_defconfig
>> index 344a4d8f9c..5f50298a58 100644
>> --- a/configs/ast2600_openbmc_spl_emmc_defconfig
>> +++ b/configs/ast2600_openbmc_spl_emmc_defconfig
>> @@ -11,6 +11,7 @@ CONFIG_SYS_TEXT_BASE=0x81000000
>>   CONFIG_ASPEED_AST2600=y
>>   # CONFIG_ASPEED_LOADERS is not set
>>   CONFIG_TARGET_EVB_AST2600A1=y
>> +CONFIG_SPL_GPIO_SUPPORT=y
>>   CONFIG_SPL_LIBCOMMON_SUPPORT=y
>>   CONFIG_SPL_LIBGENERIC_SUPPORT=y
>>   CONFIG_SYS_MALLOC_F_LEN=0x2000
>> @@ -19,7 +20,7 @@ CONFIG_SPL_SERIAL_SUPPORT=y
>>   CONFIG_SPL_DRIVERS_MISC_SUPPORT=y
>>   CONFIG_ENV_SIZE=0x10000
>>   CONFIG_ENV_OFFSET=0x5000
>> -CONFIG_SPL_SYS_MALLOC_F_LEN=0x800
>> +CONFIG_SPL_SYS_MALLOC_F_LEN=0x1000
> How much capacity does this leave us with? Have you looked at the
> memory layout for the SPL (I haven't, so any legwork you do here is
> appreciated ;) )?


I'm not sure, I haven't looked into it that much. When I was debugging, 
trying to figure out why my SPL wouldn't load, we were right at capacity 
without the GPIO stuff - allocating like 0x7c0 or so. We should have 
plenty more room now. I guess I'm not sure where that memory comes from 
anyway.


Thanks,

Eddie


>
>>   CONFIG_SPL=y
>>   CONFIG_SPL_STACK_R_ADDR=0x90300000
>>   CONFIG_ARMV7_BOOT_SEC_DEFAULT=y
>> @@ -94,6 +95,7 @@ CONFIG_CLK=y
>>   CONFIG_SPL_CLK=y
>>   CONFIG_ASPEED_HACE=y
>>   CONFIG_DM_GPIO=y
>> +CONFIG_SPL_GPIO_HOG=y
>>   CONFIG_ASPEED_GPIO=y
>>   CONFIG_DM_I2C=y
>>   CONFIG_SYS_I2C_ASPEED=y
>> -- 
>> 2.27.0

Re: [PATCH U-Boot v2019.04-aspeed-openbmc 5/6] Add GPIO hogging support for AST2600 openbmc config

[Andrew Jeffery]

On Fri, 4 Feb 2022, at 02:29, Eddie James wrote:
> On 2/2/22 20:13, Andrew Jeffery wrote:
>>
>> On Tue, 25 Jan 2022, at 05:45, Eddie James wrote:
>>> Enable GPIO support in the SPL and hog the GPIOs in the SPL only. Also
>>> increase the size of the malloc size in the SPL to get the GPIO driver
>>> loaded.
>>>
>>> Signed-off-by: Eddie James <eajames@linux.ibm.com>
>>> ---
>>>   configs/ast2600_openbmc_spl_emmc_defconfig | 4 +++-
>>>   1 file changed, 3 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/configs/ast2600_openbmc_spl_emmc_defconfig
>>> b/configs/ast2600_openbmc_spl_emmc_defconfig
>>> index 344a4d8f9c..5f50298a58 100644
>>> --- a/configs/ast2600_openbmc_spl_emmc_defconfig
>>> +++ b/configs/ast2600_openbmc_spl_emmc_defconfig
>>> @@ -11,6 +11,7 @@ CONFIG_SYS_TEXT_BASE=0x81000000
>>>   CONFIG_ASPEED_AST2600=y
>>>   # CONFIG_ASPEED_LOADERS is not set
>>>   CONFIG_TARGET_EVB_AST2600A1=y
>>> +CONFIG_SPL_GPIO_SUPPORT=y
>>>   CONFIG_SPL_LIBCOMMON_SUPPORT=y
>>>   CONFIG_SPL_LIBGENERIC_SUPPORT=y
>>>   CONFIG_SYS_MALLOC_F_LEN=0x2000
>>> @@ -19,7 +20,7 @@ CONFIG_SPL_SERIAL_SUPPORT=y
>>>   CONFIG_SPL_DRIVERS_MISC_SUPPORT=y
>>>   CONFIG_ENV_SIZE=0x10000
>>>   CONFIG_ENV_OFFSET=0x5000
>>> -CONFIG_SPL_SYS_MALLOC_F_LEN=0x800
>>> +CONFIG_SPL_SYS_MALLOC_F_LEN=0x1000
>> How much capacity does this leave us with? Have you looked at the
>> memory layout for the SPL (I haven't, so any legwork you do here is
>> appreciated ;) )?
>
>
> I'm not sure, I haven't looked into it that much. When I was debugging, 
> trying to figure out why my SPL wouldn't load, we were right at capacity 
> without the GPIO stuff - allocating like 0x7c0 or so. We should have 
> plenty more room now. I guess I'm not sure where that memory comes from 
> anyway.

Okay. Might be something for another day.

[PATCH U-Boot v2019.04-aspeed-openbmc 6/6] ast2600: Add GPIO controller and hog TPM reset pin

[Eddie James]

Hog the GPIO pin to reset the TPM.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 arch/arm/dts/ast2600-rainier.dts | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/arm/dts/ast2600-rainier.dts b/arch/arm/dts/ast2600-rainier.dts
index aae507b4c2..d0e82d1512 100755
--- a/arch/arm/dts/ast2600-rainier.dts
+++ b/arch/arm/dts/ast2600-rainier.dts
@@ -108,3 +108,14 @@
 	u-boot,dm-pre-reloc;
 	status = "okay";
 };
+
+&gpio0 {
+	u-boot,dm-pre-reloc;
+
+	tpm_reset {
+		u-boot,dm-pre-reloc;
+		gpio-hog;
+		output-high;
+		gpios = <ASPEED_GPIO(R, 0) GPIO_ACTIVE_HIGH>;
+	};
+};
-- 
2.27.0

Re: [PATCH U-Boot v2019.04-aspeed-openbmc 6/6] ast2600: Add GPIO controller and hog TPM reset pin

[Andrew Jeffery]

On Tue, 25 Jan 2022, at 05:45, Eddie James wrote:
> Hog the GPIO pin to reset the TPM.
>
> Signed-off-by: Eddie James <eajames@linux.ibm.com>
> ---
>  arch/arm/dts/ast2600-rainier.dts | 11 +++++++++++
>  1 file changed, 11 insertions(+)
>
> diff --git a/arch/arm/dts/ast2600-rainier.dts b/arch/arm/dts/ast2600-rainier.dts
> index aae507b4c2..d0e82d1512 100755
> --- a/arch/arm/dts/ast2600-rainier.dts
> +++ b/arch/arm/dts/ast2600-rainier.dts
> @@ -108,3 +108,14 @@
>  	u-boot,dm-pre-reloc;
>  	status = "okay";
>  };
> +
> +&gpio0 {
> +	u-boot,dm-pre-reloc;
> +
> +	tpm_reset {
> +		u-boot,dm-pre-reloc;

Do we need this in the hog node? Seems like it's only necessary in controller nodes.

> +		gpio-hog;
> +		output-high;
> +		gpios = <ASPEED_GPIO(R, 0) GPIO_ACTIVE_HIGH>;
> +	};
> +};
> -- 
> 2.27.0

Re: [PATCH U-Boot v2019.04-aspeed-openbmc 6/6] ast2600: Add GPIO controller and hog TPM reset pin

[Eddie James]

On 2/2/22 20:17, Andrew Jeffery wrote:
>
> On Tue, 25 Jan 2022, at 05:45, Eddie James wrote:
>> Hog the GPIO pin to reset the TPM.
>>
>> Signed-off-by: Eddie James <eajames@linux.ibm.com>
>> ---
>>   arch/arm/dts/ast2600-rainier.dts | 11 +++++++++++
>>   1 file changed, 11 insertions(+)
>>
>> diff --git a/arch/arm/dts/ast2600-rainier.dts b/arch/arm/dts/ast2600-rainier.dts
>> index aae507b4c2..d0e82d1512 100755
>> --- a/arch/arm/dts/ast2600-rainier.dts
>> +++ b/arch/arm/dts/ast2600-rainier.dts
>> @@ -108,3 +108,14 @@
>>   	u-boot,dm-pre-reloc;
>>   	status = "okay";
>>   };
>> +
>> +&gpio0 {
>> +	u-boot,dm-pre-reloc;
>> +
>> +	tpm_reset {
>> +		u-boot,dm-pre-reloc;
> Do we need this in the hog node? Seems like it's only necessary in controller nodes.


Yes it is necessary, the SPL dtc compiler will cull anything without 
that property.


Thanks,

Eddie


>
>> +		gpio-hog;
>> +		output-high;
>> +		gpios = <ASPEED_GPIO(R, 0) GPIO_ACTIVE_HIGH>;
>> +	};
>> +};
>> -- 
>> 2.27.0

Re: [PATCH U-Boot v2019.04-aspeed-openbmc 6/6] ast2600: Add GPIO controller and hog TPM reset pin

[Andrew Jeffery]

On Fri, 4 Feb 2022, at 02:31, Eddie James wrote:
> On 2/2/22 20:17, Andrew Jeffery wrote:
>>
>> On Tue, 25 Jan 2022, at 05:45, Eddie James wrote:
>>> Hog the GPIO pin to reset the TPM.
>>>
>>> Signed-off-by: Eddie James <eajames@linux.ibm.com>
>>> ---
>>>   arch/arm/dts/ast2600-rainier.dts | 11 +++++++++++
>>>   1 file changed, 11 insertions(+)
>>>
>>> diff --git a/arch/arm/dts/ast2600-rainier.dts b/arch/arm/dts/ast2600-rainier.dts
>>> index aae507b4c2..d0e82d1512 100755
>>> --- a/arch/arm/dts/ast2600-rainier.dts
>>> +++ b/arch/arm/dts/ast2600-rainier.dts
>>> @@ -108,3 +108,14 @@
>>>   	u-boot,dm-pre-reloc;
>>>   	status = "okay";
>>>   };
>>> +
>>> +&gpio0 {
>>> +	u-boot,dm-pre-reloc;
>>> +
>>> +	tpm_reset {
>>> +		u-boot,dm-pre-reloc;
>> Do we need this in the hog node? Seems like it's only necessary in controller nodes.
>
>
> Yes it is necessary, the SPL dtc compiler will cull anything without 
> that property.

Are you sure it's done at dts translation time?

My understanding is the driver model core will only instantiate drivers 
for devices with the property. This suggests all nodes are retained.

I used uclass_get_device_by_driver() in the mach-aspeed patch which 
will forcibly probe the driver.

Andrew

Re: [PATCH U-Boot v2019.04-aspeed-openbmc 6/6] ast2600: Add GPIO controller and hog TPM reset pin

[Eddie James]

On 2/3/22 16:12, Andrew Jeffery wrote:
>
> On Fri, 4 Feb 2022, at 02:31, Eddie James wrote:
>> On 2/2/22 20:17, Andrew Jeffery wrote:
>>> On Tue, 25 Jan 2022, at 05:45, Eddie James wrote:
>>>> Hog the GPIO pin to reset the TPM.
>>>>
>>>> Signed-off-by: Eddie James <eajames@linux.ibm.com>
>>>> ---
>>>>    arch/arm/dts/ast2600-rainier.dts | 11 +++++++++++
>>>>    1 file changed, 11 insertions(+)
>>>>
>>>> diff --git a/arch/arm/dts/ast2600-rainier.dts b/arch/arm/dts/ast2600-rainier.dts
>>>> index aae507b4c2..d0e82d1512 100755
>>>> --- a/arch/arm/dts/ast2600-rainier.dts
>>>> +++ b/arch/arm/dts/ast2600-rainier.dts
>>>> @@ -108,3 +108,14 @@
>>>>    	u-boot,dm-pre-reloc;
>>>>    	status = "okay";
>>>>    };
>>>> +
>>>> +&gpio0 {
>>>> +	u-boot,dm-pre-reloc;
>>>> +
>>>> +	tpm_reset {
>>>> +		u-boot,dm-pre-reloc;
>>> Do we need this in the hog node? Seems like it's only necessary in controller nodes.
>>
>> Yes it is necessary, the SPL dtc compiler will cull anything without
>> that property.
> Are you sure it's done at dts translation time?
>
> My understanding is the driver model core will only instantiate drivers
> for devices with the property. This suggests all nodes are retained.
>
> I used uclass_get_device_by_driver() in the mach-aspeed patch which
> will forcibly probe the driver.


Well, I can use fdtdump and compare the outputs. It looks to me like the 
node wouldn't be in the SPL dts at all without that property, unless 
fdtdump simply isn't detecting it in that case for some reason.

With the property:

$ fdtdump spl/u-boot-spl.dtb

**** fdtdump is a low-level debugging tool, not meant for general use.
**** If you want to decompile a dtb, you probably want
****     dtc -I dtb -O dts <filename>

/dts-v1/;
// magic:               0xd00dfeed
// totalsize:           0xa46 (2630)
// off_dt_struct:       0x38
// off_dt_strings:      0x8b0
// off_mem_rsvmap:      0x28
// version:             17
// last_comp_version:   2
// boot_cpuid_phys:     0x0
// size_dt_strings:     0x196
// size_dt_struct:      0x878

/ {
     #address-cells = <0x00000001>;
     #size-cells = <0x00000001>;
     model = Rainier;
     compatible = ibm,rainier-bmc, aspeed,ast2600;
     chosen {
         stdout-path = /ahb/apb/serial@1e784000;
     };
     aliases {
         serial4 = /ahb/apb/serial@1e784000;
         mmc0 = /ahb/apb/emmc@1e750000/emmc_slot0@100;
     };
     ahb {
         compatible = simple-bus;
         #address-cells = <0x00000001>;
         #size-cells = <0x00000001>;
         device_type = soc;
         ranges;
         u-boot,dm-pre-reloc;
         apb {
             compatible = simple-bus;
             #address-cells = <0x00000001>;
             #size-cells = <0x00000001>;
             ranges;
             u-boot,dm-pre-reloc;
             hace@1e6d0000 {
                 compatible = aspeed,ast2600-hace;
                 reg = <0x1e6d0000 0x00000200>;
                 interrupts = <0x00000000 0x00000004 0x00000004>;
                 clocks = <0x00000002 0x00000007>;
                 clock-names = yclk;
                 status = okay;
                 u-boot,dm-pre-reloc;
             };
             emmc@1e750000 {
                 #interrupt-cells = <0x00000001>;
                 compatible = aspeed,aspeed-emmc-irq, simple-mfd;
                 reg = <0x1e750000 0x00001000>;
                 interrupts = <0x00000000 0x0000000f 0x00000004>;
                 interrupt-controller;
                 clocks = <0x00000002 0x0000001f 0x00000002 0x00000020>;
                 clock-names = ctrlclk, extclk;
                 #address-cells = <0x00000001>;
                 #size-cells = <0x00000001>;
                 ranges = <0x00000000 0x1e750000 0x00001000>;
                 u-boot,dm-pre-reloc;
                 timing-phase = <0x000700ff>;
                 phandle = <0x00000012>;
                 emmc_slot0@100 {
                     compatible = aspeed,emmc-ast2600;
                     reg = <0x00000100 0x00000100>;
                     interrupts = <0x00000000>;
                     clocks = <0x00000002 0x00000035>;
                     status = okay;
                     u-boot,dm-pre-reloc;
                     bus-width = <0x00000004>;
                     sdhci-drive-type = <0x00000001>;
                 };
             };
             gpio@1e780000 {
                 compatible = aspeed,ast2600-gpio;
                 reg = <0x1e780000 0x00000400>;
                 interrupts = <0x00000000 0x00000028 0x00000004>;
                 #gpio-cells = <0x00000002>;
                 gpio-controller;
                 interrupt-controller;
                 gpio-ranges = <0x00000014 0x00000000 0x00000000 
0x000000d0>;
                 ngpios = <0x000000d0>;
                 u-boot,dm-pre-reloc;
                 tpm_reset {
                     u-boot,dm-pre-reloc;
                     gpio-hog;
                     output-high;
                     gpios = <0x00000088 0x00000000>;
                 };
             };
             serial@1e784000 {
                 compatible = ns16550a;
                 reg = <0x1e784000 0x00001000>;
                 reg-shift = <0x00000002>;
                 interrupts = <0x00000000 0x00000024 0x00000004>;
                 clocks = <0x00000002 0x0000000f>;
                 clock-frequency = <0x001c2b8a>;
                 no-loopback-test;
                 status = okay;
                 u-boot,dm-pre-reloc;
             };
             watchdog@1e785040 {
                 compatible = aspeed,ast2600-wdt;
                 reg = <0x1e785040 0x00000040>;
                 u-boot,dm-pre-reloc;
                 status = okay;
             };
         };
     };
     clock-controller@1e6e2000 {
         compatible = aspeed,ast2600-scu;
         reg = <0x1e6e2000 0x00001000>;
         u-boot,dm-pre-reloc;
         #clock-cells = <0x00000001>;
         #reset-cells = <0x00000001>;
         uart-clk-source = <0x00000000>;
         phandle = <0x00000002>;
     };
     reset-controller {
         u-boot,dm-pre-reloc;
         compatible = aspeed,ast2600-reset;
         aspeed,wdt = <0x00000017>;
         #reset-cells = <0x00000001>;
         phandle = <0x00000004>;
     };
     sdrammc@1e6e0000 {
         u-boot,dm-pre-reloc;
         compatible = aspeed,ast2600-sdrammc;
         reg = <0x1e6e0000 0x00000100 0x1e6e0100 0x00000300 0x1e6e0400 
0x00000200>;
         #reset-cells = <0x00000001>;
         clocks = <0x00000002 0x00000033>;
         resets = <0x00000004 0x00000000>;
         clock-frequency = <0x17d78400>;
     };
};


Without the property:

$ fdtdump spl/u-boot-spl.dtb

**** fdtdump is a low-level debugging tool, not meant for general use.
**** If you want to decompile a dtb, you probably want
****     dtc -I dtb -O dts <filename>

/dts-v1/;
// magic:               0xd00dfeed
// totalsize:           0x9e5 (2533)
// off_dt_struct:       0x38
// off_dt_strings:      0x864
// off_mem_rsvmap:      0x28
// version:             17
// last_comp_version:   2
// boot_cpuid_phys:     0x0
// size_dt_strings:     0x181
// size_dt_struct:      0x82c

/ {
     #address-cells = <0x00000001>;
     #size-cells = <0x00000001>;
     model = Rainier;
     compatible = ibm,rainier-bmc, aspeed,ast2600;
     chosen {
         stdout-path = /ahb/apb/serial@1e784000;
     };
     aliases {
         serial4 = /ahb/apb/serial@1e784000;
         mmc0 = /ahb/apb/emmc@1e750000/emmc_slot0@100;
     };
     ahb {
         compatible = simple-bus;
         #address-cells = <0x00000001>;
         #size-cells = <0x00000001>;
         device_type = soc;
         ranges;
         u-boot,dm-pre-reloc;
         apb {
             compatible = simple-bus;
             #address-cells = <0x00000001>;
             #size-cells = <0x00000001>;
             ranges;
             u-boot,dm-pre-reloc;
             hace@1e6d0000 {
                 compatible = aspeed,ast2600-hace;
                 reg = <0x1e6d0000 0x00000200>;
                 interrupts = <0x00000000 0x00000004 0x00000004>;
                 clocks = <0x00000002 0x00000007>;
                 clock-names = yclk;
                 status = okay;
                 u-boot,dm-pre-reloc;
             };
             emmc@1e750000 {
                 #interrupt-cells = <0x00000001>;
                 compatible = aspeed,aspeed-emmc-irq, simple-mfd;
                 reg = <0x1e750000 0x00001000>;
                 interrupts = <0x00000000 0x0000000f 0x00000004>;
                 interrupt-controller;
                 clocks = <0x00000002 0x0000001f 0x00000002 0x00000020>;
                 clock-names = ctrlclk, extclk;
                 #address-cells = <0x00000001>;
                 #size-cells = <0x00000001>;
                 ranges = <0x00000000 0x1e750000 0x00001000>;
                 u-boot,dm-pre-reloc;
                 timing-phase = <0x000700ff>;
                 phandle = <0x00000012>;
                 emmc_slot0@100 {
                     compatible = aspeed,emmc-ast2600;
                     reg = <0x00000100 0x00000100>;
                     interrupts = <0x00000000>;
                     clocks = <0x00000002 0x00000035>;
                     status = okay;
                     u-boot,dm-pre-reloc;
                     bus-width = <0x00000004>;
                     sdhci-drive-type = <0x00000001>;
                 };
             };
             gpio@1e780000 {
                 compatible = aspeed,ast2600-gpio;
                 reg = <0x1e780000 0x00000400>;
                 interrupts = <0x00000000 0x00000028 0x00000004>;
                 #gpio-cells = <0x00000002>;
                 gpio-controller;
                 interrupt-controller;
                 gpio-ranges = <0x00000014 0x00000000 0x00000000 
0x000000d0>;
                 ngpios = <0x000000d0>;
                 u-boot,dm-pre-reloc;
             };
             serial@1e784000 {
                 compatible = ns16550a;
                 reg = <0x1e784000 0x00001000>;
                 reg-shift = <0x00000002>;
                 interrupts = <0x00000000 0x00000024 0x00000004>;
                 clocks = <0x00000002 0x0000000f>;
                 clock-frequency = <0x001c2b8a>;
                 no-loopback-test;
                 status = okay;
                 u-boot,dm-pre-reloc;
             };
             watchdog@1e785040 {
                 compatible = aspeed,ast2600-wdt;
                 reg = <0x1e785040 0x00000040>;
                 u-boot,dm-pre-reloc;
                 status = okay;
             };
         };
     };
     clock-controller@1e6e2000 {
         compatible = aspeed,ast2600-scu;
         reg = <0x1e6e2000 0x00001000>;
         u-boot,dm-pre-reloc;
         #clock-cells = <0x00000001>;
         #reset-cells = <0x00000001>;
         uart-clk-source = <0x00000000>;
         phandle = <0x00000002>;
     };
     reset-controller {
         u-boot,dm-pre-reloc;
         compatible = aspeed,ast2600-reset;
         aspeed,wdt = <0x00000017>;
         #reset-cells = <0x00000001>;
         phandle = <0x00000004>;
     };
     sdrammc@1e6e0000 {
         u-boot,dm-pre-reloc;
         compatible = aspeed,ast2600-sdrammc;
         reg = <0x1e6e0000 0x00000100 0x1e6e0100 0x00000300 0x1e6e0400 
0x00000200>;
         #reset-cells = <0x00000001>;
         clocks = <0x00000002 0x00000033>;
         resets = <0x00000004 0x00000000>;
         clock-frequency = <0x17d78400>;
     };
};



>
> Andrew