[PATCH 00/10] Add support for extension boards detection and DT overlays application

[PATCH 00/10] Add support for extension boards detection and DT overlays application

[Kory Maincent]

This series of patches aims at proposing a generic U-Boot mechanism to
detect extension boards connected to the HW platform, and apply the
appropriate Device Tree overlays depending on the detected extension
boards.

Indeed, numerous popular platforms, such as the BeagleBone or the
RaspberryPi, feature some kind of extension board mechanism. These
extension boards are often discoverable through some kind of EEPROM
(connected on I2C, 1-wire, etc.) and require Device Tree overlays to be
applied at the U-Boot level to provide a complete HW description to the
Linux kernel. However, currently this logic is usually implemented
ad-hoc in downstream forks of U-Boot.

This series proposes to bring a HW-agnostic and generic solution to
this problem to upstream U-Boot. The series shows that it is generic
enough by implementing its usage for 2 different families of HW
platforms and expansion boards:

 - The BeagleBone Black and BeagleBone AI, that use extension boards
   where the EEPROM describing the extension boards is connected over
   I2C.

 - The CHIP, that uses extension boards where the EEPROM describing the
   extension boards is connected over 1-wire.

The patch series implements a new command called "extension", with two
sub-commands:

 - "extension scan" to detect available extension boards

 - "extension list" will simply list the detected extension boards

 - "extension apply" will allow to apply the Device Tree overlays
   corresponding to one extension board or to all expansion boards

Note that the name "extension" has been chosen to not refer to any
particular board-specific terminology for extension boards ("cape" for
BeagleBone, "DIP" for CHIP, "hat" for RaspberryPi, etc.). However, we
welcome suggestions of other names and are definitely willing to use a
different naming.

The "extension apply" command requires two environment variables to be
defined so that it knows how to apply DT overlays. This is described
in more details in PATCH 1.

This generic code requires board-specific code for the detection and
enumeration of extension boards. This is simply implemented in the form
of a board-specific extension_board_scan() function, which fills in a
list of detected extension boards.

In detail:

 - PATCH 1 move fdt_valid function to fdt_support file
 - PATCH 2 implements the generic command and logic
 - PATCH 3 implements the python test for the "extension" command
 - PATCH 4 implements the board-specific code for the BeagleBone platforms
 - PATCH 5 enables the mechanism for the BeagleBone AI
 - PATCH 6 to 8 enable the mechanism for the CHIP
 - PATCH 9 and 10 enable the mechanism for the BeagleBone Black

Thanks in advance for your review and feedback

Kory Maincent (10):
  fdt_support: move fdt_valid from cmd_fdt.c to fdt_support.c
  cmd: add support for a new "extension" command
  pytest: add sandbox test for "extension" command
  ti/common: add support for extension_scan_board function
  am57xx: add support for cape detect functionality
  arm: dts: sun5i: enable one-wire on the CHIP
  arm: mach-sunxi: add CHIP board target
  sun5i: add support for DIP detection to CHIP board
  arm: am335x: add support for i2c2 bus
  am335x: add support for cape detect functionality

 arch/Kconfig                              |   2 +
 arch/arm/dts/sun5i-r8-chip.dts            |   6 +
 arch/arm/mach-omap2/am33xx/Kconfig        |   1 +
 arch/arm/mach-omap2/am33xx/clock_am33xx.c |   1 +
 arch/arm/mach-omap2/omap5/Kconfig         |   1 +
 arch/arm/mach-sunxi/Kconfig               |  16 +++
 arch/sandbox/dts/Makefile                 |   1 +
 arch/sandbox/dts/overlay0.dts             |   9 ++
 arch/sandbox/dts/overlay1.dts             |   9 ++
 board/sandbox/sandbox.c                   |  23 +++
 board/sunxi/Makefile                      |   1 +
 board/sunxi/chip.c                        | 104 ++++++++++++++
 board/ti/am335x/board.c                   |   3 +
 board/ti/am335x/board.h                   |   1 +
 board/ti/am335x/mux.c                     |  15 ++
 board/ti/am57xx/board.c                   |   1 +
 board/ti/common/Kconfig                   |   3 +
 board/ti/common/Makefile                  |   1 +
 board/ti/common/cape_detect.c             |  96 +++++++++++++
 board/ti/common/cape_detect.h             |  28 ++++
 cmd/Kconfig                               |  12 ++
 cmd/Makefile                              |   1 +
 cmd/extension_board.c                     | 167 ++++++++++++++++++++++
 cmd/fdt.c                                 |  49 -------
 common/fdt_support.c                      |  46 ++++++
 configs/CHIP_defconfig                    |   1 +
 doc/README.extension                      |  80 +++++++++++
 include/configs/am335x_evm.h              |   2 +
 include/configs/am57xx_evm.h              |   2 +
 include/extension_board.h                 |  31 ++++
 include/fdt_support.h                     |   2 +
 test/py/tests/test_extension.py           |  52 +++++++
 32 files changed, 718 insertions(+), 49 deletions(-)
 create mode 100644 arch/sandbox/dts/overlay0.dts
 create mode 100644 arch/sandbox/dts/overlay1.dts
 create mode 100644 board/sunxi/chip.c
 create mode 100644 board/ti/common/cape_detect.c
 create mode 100644 board/ti/common/cape_detect.h
 create mode 100644 cmd/extension_board.c
 create mode 100644 doc/README.extension
 create mode 100644 include/extension_board.h
 create mode 100644 test/py/tests/test_extension.py

-- 
2.17.1

[PATCH 01/10] fdt_support: move fdt_valid from cmd_fdt.c to fdt_support.c

[Kory Maincent]

Move the fdt_valid function to fdt_support.
This changes allow to be able to test the validity of a devicetree in
other c files.

Update code syntax.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
---
 cmd/fdt.c             | 49 -------------------------------------------
 common/fdt_support.c  | 46 ++++++++++++++++++++++++++++++++++++++++
 include/fdt_support.h |  2 ++
 3 files changed, 48 insertions(+), 49 deletions(-)

diff --git a/cmd/fdt.c b/cmd/fdt.c
index 89ab572d8d..f1e2fc2fd8 100644
--- a/cmd/fdt.c
+++ b/cmd/fdt.c
@@ -27,7 +27,6 @@
  */
 DECLARE_GLOBAL_DATA_PTR;
 
-static int fdt_valid(struct fdt_header **blobp);
 static int fdt_parse_prop(char *const*newval, int count, char *data, int *len);
 static int fdt_print(const char *pathp, char *prop, int depth);
 static int is_printable_string(const void *data, int len);
@@ -732,54 +731,6 @@ static int do_fdt(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 
 /****************************************************************************/
 
-/**
- * fdt_valid() - Check if an FDT is valid. If not, change it to NULL
- *
- * @blobp: Pointer to FDT pointer
- * @return 1 if OK, 0 if bad (in which case *blobp is set to NULL)
- */
-static int fdt_valid(struct fdt_header **blobp)
-{
-	const void *blob = *blobp;
-	int err;
-
-	if (blob == NULL) {
-		printf ("The address of the fdt is invalid (NULL).\n");
-		return 0;
-	}
-
-	err = fdt_check_header(blob);
-	if (err == 0)
-		return 1;	/* valid */
-
-	if (err < 0) {
-		printf("libfdt fdt_check_header(): %s", fdt_strerror(err));
-		/*
-		 * Be more informative on bad version.
-		 */
-		if (err == -FDT_ERR_BADVERSION) {
-			if (fdt_version(blob) <
-			    FDT_FIRST_SUPPORTED_VERSION) {
-				printf (" - too old, fdt %d < %d",
-					fdt_version(blob),
-					FDT_FIRST_SUPPORTED_VERSION);
-			}
-			if (fdt_last_comp_version(blob) >
-			    FDT_LAST_SUPPORTED_VERSION) {
-				printf (" - too new, fdt %d > %d",
-					fdt_version(blob),
-					FDT_LAST_SUPPORTED_VERSION);
-			}
-		}
-		printf("\n");
-		*blobp = NULL;
-		return 0;
-	}
-	return 1;
-}
-
-/****************************************************************************/
-
 /*
  * Parse the user's input, partially heuristic.  Valid formats:
  * <0x00112233 4 05>	- an array of cells.  Numbers follow standard
diff --git a/common/fdt_support.c b/common/fdt_support.c
index 5ae75df3c6..84ee274c72 100644
--- a/common/fdt_support.c
+++ b/common/fdt_support.c
@@ -1814,3 +1814,49 @@ int fdt_overlay_apply_verbose(void *fdt, void *fdto)
 	return err;
 }
 #endif
+
+/**
+ * fdt_valid() - Check if an FDT is valid. If not, change it to NULL
+ *
+ * @blobp: Pointer to FDT pointer
+ * @return 1 if OK, 0 if bad (in which case *blobp is set to NULL)
+ */
+int fdt_valid(struct fdt_header **blobp)
+{
+	const void *blob = *blobp;
+	int err;
+
+	if (!blob) {
+		printf("The address of the fdt is invalid (NULL).\n");
+		return 0;
+	}
+
+	err = fdt_check_header(blob);
+	if (err == 0)
+		return 1;	/* valid */
+
+	if (err < 0) {
+		printf("libfdt fdt_check_header(): %s", fdt_strerror(err));
+		/*
+		 * Be more informative on bad version.
+		 */
+		if (err == -FDT_ERR_BADVERSION) {
+			if (fdt_version(blob) <
+			    FDT_FIRST_SUPPORTED_VERSION) {
+				printf(" - too old, fdt %d < %d",
+				       fdt_version(blob),
+				       FDT_FIRST_SUPPORTED_VERSION);
+			}
+			if (fdt_last_comp_version(blob) >
+			    FDT_LAST_SUPPORTED_VERSION) {
+				printf(" - too new, fdt %d > %d",
+				       fdt_version(blob),
+				       FDT_LAST_SUPPORTED_VERSION);
+			}
+		}
+		printf("\n");
+		*blobp = NULL;
+		return 0;
+	}
+	return 1;
+}
diff --git a/include/fdt_support.h b/include/fdt_support.h
index dbbac0fb6a..fab8df0bcb 100644
--- a/include/fdt_support.h
+++ b/include/fdt_support.h
@@ -328,6 +328,8 @@ int fdt_setup_simplefb_node(void *fdt, int node, u64 base_address, u32 width,
 
 int fdt_overlay_apply_verbose(void *fdt, void *fdto);
 
+int fdt_valid(struct fdt_header **blobp);
+
 /**
  * fdt_get_cells_len() - Get the length of a type of cell in top-level nodes
  *
-- 
2.17.1

[PATCH 02/10] cmd: add support for a new "extension" command

[Kory Maincent]

This patch adds a new "extension" command, which aims at detecting
extension boards connected to the hardware platform, and apply the
Device Tree overlays that describe the hardware present on those
extension boards.

In order to enable this mechanism, board-specific code must implement
the extension_board_scan() function that fills in a linked list of
"struct extension", each describing one extension board. In addition,
the board-specific code must select the SUPPORT_EXTENSION_SCAN Kconfig
boolean.

Based on this:

 - "extension scan" makes the generic code call the board-specific
   extension_board_scan() function to retrieve the list of detected
   extension boards.

 - "extension list" allows to list the detected extension boards.

 - "extension apply <number>|all" allows to apply the Device Tree
   overlay(s) corresponding to one, or all, extension boards

The latter requires two environment variables to exist:

 - extension_overlay_addr: the RAM address where to load the Device
   Tree overlays

 - extension_overlay_cmd: the U-Boot command to load one overlay.
   Indeed, the location and mechanism to load DT overlays is very setup
   specific.

When calling the command described in the extension_overlay_cmd
variable, the variable extension_overlay_name will be defined. So a
typical extension_overlay_cmd will look like this:

  extension_overlay_cmd=load mmc 0:1 $extension_overlay_addr /boot/$extension_overlay_name

Here is an example on how to use it:
=> run loadfdt
=> fdt addr $fdtaddr
=> setenv extension_overlay_addr 0x1000
=> setenv extension_overlay_cmd 'load mmc 0:1 ${extension_overlay_addr} /boot/${extension_overlay_name}'
=> extension scan
Found 1 extension board(s).
=> extension apply 0
519 bytes read in 3 ms (168.9 KiB/s)

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
---
 cmd/Kconfig               |  12 +++
 cmd/Makefile              |   1 +
 cmd/extension_board.c     | 167 ++++++++++++++++++++++++++++++++++++++
 doc/README.extension      |  80 ++++++++++++++++++
 include/extension_board.h |  31 +++++++
 5 files changed, 291 insertions(+)
 create mode 100644 cmd/extension_board.c
 create mode 100644 doc/README.extension
 create mode 100644 include/extension_board.h

diff --git a/cmd/Kconfig b/cmd/Kconfig
index 1595de999b..90be5c260a 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -314,6 +314,18 @@ config CMD_FDT
 	help
 	  Do FDT related setup before booting into the Operating System.
 
+config SUPPORT_EXTENSION_SCAN
+	bool
+
+config CMD_EXTENSION
+	bool "Extension board management command"
+	select CMD_FDT
+	depends on SUPPORT_EXTENSION_SCAN
+	help
+	  Enables the "extension" command, which allows to detect
+	  extension boards connected to the system, and apply
+	  corresponding Device Tree overlays.
+
 config CMD_GO
 	bool "go"
 	default y
diff --git a/cmd/Makefile b/cmd/Makefile
index dd86675bf2..87da67d27d 100644
--- a/cmd/Makefile
+++ b/cmd/Makefile
@@ -53,6 +53,7 @@ obj-$(CONFIG_CMD_DIAG) += diag.o
 endif
 obj-$(CONFIG_CMD_ADTIMG) += adtimg.o
 obj-$(CONFIG_CMD_ABOOTIMG) += abootimg.o
+obj-$(CONFIG_CMD_EXTENSION) += extension_board.o
 obj-$(CONFIG_CMD_ECHO) += echo.o
 obj-$(CONFIG_ENV_IS_IN_EEPROM) += eeprom.o
 obj-$(CONFIG_CMD_EEPROM) += eeprom.o
diff --git a/cmd/extension_board.c b/cmd/extension_board.c
new file mode 100644
index 0000000000..4fed84da2d
--- /dev/null
+++ b/cmd/extension_board.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2021
+ * K?ry Maincent, Bootlin, <kory.maincent@bootlin.com>
+ */
+
+#include <common.h>
+#include <command.h>
+#include <malloc.h>
+#include <extension_board.h>
+#include <mapmem.h>
+#include <linux/libfdt.h>
+#include <fdt_support.h>
+
+static LIST_HEAD(extension_list);
+
+static int extension_apply(struct extension *extension)
+{
+	char *overlay_cmd;
+	ulong extrasize, overlay_addr;
+	struct fdt_header *blob;
+
+	if (!working_fdt) {
+		puts(
+			"No FDT memory address configured. Please configure\n"
+			"the FDT address via \"fdt addr <address>\" command.\n");
+		return CMD_RET_FAILURE;
+	}
+
+	overlay_cmd = env_get("extension_overlay_cmd");
+	if (!overlay_cmd) {
+		printf("Environment extension_overlay_cmd is missing\n");
+		return CMD_RET_FAILURE;
+	}
+
+	overlay_addr = env_get_hex("extension_overlay_addr", 0);
+	if (!overlay_addr) {
+		printf("Environment extension_overlay_addr is missing\n");
+		return CMD_RET_FAILURE;
+	}
+
+	env_set("extension_overlay_name", extension->overlay);
+	if (run_command(overlay_cmd, 0) != 0)
+		return CMD_RET_FAILURE;
+
+	extrasize = env_get_hex("filesize", 0);
+	if (!extrasize)
+		return CMD_RET_FAILURE;
+
+	fdt_shrink_to_minimum(working_fdt, extrasize);
+
+	blob = map_sysmem(overlay_addr, 0);
+	if (!fdt_valid(&blob))
+		return CMD_RET_FAILURE;
+
+	/* apply method prints messages on error */
+	if (fdt_overlay_apply_verbose(working_fdt, blob))
+		return CMD_RET_FAILURE;
+
+	return CMD_RET_SUCCESS;
+}
+
+static int do_extension_list(struct cmd_tbl *cmdtp, int flag,
+			     int argc, char *const argv[])
+{
+	int i;
+	struct extension *extension;
+
+	if (list_empty(&extension_list)) {
+		printf("No extension registered - Please run \"extension scan\"\n");
+		return CMD_RET_SUCCESS;
+	}
+
+	list_for_each_entry(extension, &extension_list, list) {
+		printf("Extension %d: %s\n", i++, extension->name);
+		printf("\tManufacturer: \t\t%s\n", extension->owner);
+		printf("\tVersion: \t\t%s\n", extension->version);
+		printf("\tDevicetree overlay: \t%s\n", extension->overlay);
+		printf("\tOther information: \t%s\n", extension->other);
+	}
+	return CMD_RET_SUCCESS;
+}
+
+static int do_extension_scan(struct cmd_tbl *cmdtp, int flag,
+			     int argc, char *const argv[])
+{
+	struct extension *extension, *next;
+	int extension_num;
+
+	list_for_each_entry_safe(extension, next, &extension_list, list) {
+		list_del(&extension->list);
+		free(extension);
+	}
+	extension_num = extension_board_scan(&extension_list);
+
+	if (extension_num < 0)
+		return CMD_RET_FAILURE;
+
+	printf("Found %d extension board(s).\n", extension_num);
+
+	return CMD_RET_SUCCESS;
+}
+
+static int do_extension_apply(struct cmd_tbl *cmdtp, int flag,
+			      int argc, char *const argv[])
+{
+	struct extension *extension = NULL;
+	struct list_head *entry;
+	int i = 0, extension_id, ret;
+
+	if (argc < 2)
+		return CMD_RET_USAGE;
+
+	if (strcmp(argv[1], "all") == 0) {
+		list_for_each_entry(extension, &extension_list, list)
+			ret = extension_apply(extension);
+			if (ret != CMD_RET_SUCCESS)
+				break;
+	} else {
+		extension_id = simple_strtol(argv[1], NULL, 10);
+		list_for_each(entry, &extension_list) {
+			if (i == extension_id) {
+				extension = list_entry(entry, struct extension,  list);
+				break;
+			}
+			i++;
+		}
+
+		if (!extension) {
+			printf("Wrong extension number\n");
+			return CMD_RET_FAILURE;
+		}
+
+		ret = extension_apply(extension);
+	}
+
+	return ret;
+}
+
+static struct cmd_tbl cmd_extension[] = {
+	U_BOOT_CMD_MKENT(scan, 1, 1, do_extension_scan, "", ""),
+	U_BOOT_CMD_MKENT(list, 1, 0, do_extension_list, "", ""),
+	U_BOOT_CMD_MKENT(apply, 2, 0, do_extension_apply, "", ""),
+};
+
+static int do_extensionops(struct cmd_tbl *cmdtp, int flag, int argc,
+			   char *const argv[])
+{
+	struct cmd_tbl *cp;
+
+	/* Drop the extension command */
+	argc--;
+	argv++;
+
+	cp = find_cmd_tbl(argv[0], cmd_extension, ARRAY_SIZE(cmd_extension));
+	if (cp)
+		return cp->cmd(cmdtp, flag, argc, argv);
+
+	return CMD_RET_USAGE;
+}
+
+U_BOOT_CMD(extension, 3, 1, do_extensionops,
+	"Extension board management sub system",
+	"scan - scan plugged extension(s) board(s)\n"
+	"extension list - lists available extension(s) board(s)\n"
+	"extension apply <extension number|all> - applies DT overlays corresponding to extension boards\n"
+);
diff --git a/doc/README.extension b/doc/README.extension
new file mode 100644
index 0000000000..6face05084
--- /dev/null
+++ b/doc/README.extension
@@ -0,0 +1,80 @@
+U-Boot extension board usage (CONFIG_EXTENSION)
+===============================================
+
+The "extension" command proposes a generic U-Boot mechanism to detect
+extension boards connected to the HW platform, and apply the appropriate
+Device Tree overlays depending on the detected extension boards.
+
+The "extension" command comes with three sub-commands:
+
+ - "extension scan" makes the generic code call the board-specific
+   extension_board_scan() function to retrieve the list of detected
+   extension boards.
+
+ - "extension list" allows to list the detected extension boards.
+
+ - "extension apply <number>|all" allows to apply the Device Tree
+   overlay(s) corresponding to one, or all, extension boards
+
+The latter requires two environment variables to exist:
+
+ - extension_overlay_addr: the RAM address where to load the Device
+   Tree overlays
+
+ - extension_overlay_cmd: the U-Boot command to load one overlay.
+   Indeed, the location and mechanism to load DT overlays is very setup
+   specific.
+
+In order to enable this mechanism, board-specific code must implement
+the extension_board_scan() function that fills in a linked list of
+"struct extension", each describing one extension board. In addition,
+the board-specific code must select the SUPPORT_EXTENSION_SCAN Kconfig
+boolean.
+
+Usage example
+-------------
+
+1. Make sure your devicetree is loaded and set as the working fdt tree.
+
+=> run loadfdt
+=> fdt addr $fdtaddr
+
+2. Prepare the environment variables
+
+=> setenv extension_overlay_addr 0x88080000
+=> setenv extension_overlay_cmd 'load mmc 0:1 ${extension_overlay_addr} /boot/${extension_overlay_name}'
+
+3. Detect the plugged extension board
+
+=> extension scan
+
+4. List the plugged extension board information and the devicetree
+   overlay name
+
+=> extension list
+
+5. Apply the appropriate devicetree overlay
+
+For apply the selected overlay:
+=> extension apply 0
+
+For apply all the overlays:
+=> extension apply all
+
+Simple extension_board_scan function example
+--------------------------------------------
+
+int extension_board_scan(struct list_head *extension_list)
+{
+	struct extension *extension;
+
+	extension = calloc(1, sizeof(struct extension));
+	snprintf(extension->overlay, sizeof(extension->overlay), "overlay.dtbo");
+	snprintf(extension->name, sizeof(extension->name), "extension board");
+	snprintf(extension->owner, sizeof(extension->owner), "sandbox");
+	snprintf(extension->version, sizeof(extension->version), "1.1");
+	snprintf(extension->other, sizeof(extension->other), "Extension board information");
+	list_add_tail(&extension->list, extension_list);
+
+	return 1;
+}
diff --git a/include/extension_board.h b/include/extension_board.h
new file mode 100644
index 0000000000..c530a0ad8a
--- /dev/null
+++ b/include/extension_board.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * (C) Copyright 2021
+ * K?ry Maincent, Bootlin, <kory.maincent@bootlin.com>
+ */
+
+#ifndef __EXTENSION_SUPPORT_H
+#define __EXTENSION_SUPPORT_H
+
+struct extension {
+	struct list_head list;
+	char name[32];
+	char owner[32];
+	char version[32];
+	char overlay[32];
+	char other[32];
+};
+
+/**
+ * extension_board_scan - Add system-specific function to scan extension board.
+ * @param extension_list	List of extension board information to update.
+ * @return the number of extension.
+ *
+ * This function is called if CONFIG_CMD_EXTENSION is defined.
+ * Needs to fill the list extension_list with elements.
+ * Each element need to be allocated to an extension structure.
+ *
+ */
+int extension_board_scan(struct list_head *extension_list);
+
+#endif /* __EXTENSION_SUPPORT_H */
-- 
2.17.1

[PATCH 03/10] pytest: add sandbox test for "extension" command

[Kory Maincent]

This commit extends the sandbox to implement a dummy
extension_board_scan() function and enables the extension command in
the sandbox configuration. It then adds a test that checks the proper
functionality of the extension command by applying two Device Tree
overlays to the sandbox Device Tree.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
---
 arch/Kconfig                    |  2 ++
 arch/sandbox/dts/Makefile       |  1 +
 arch/sandbox/dts/overlay0.dts   |  9 ++++++
 arch/sandbox/dts/overlay1.dts   |  9 ++++++
 board/sandbox/sandbox.c         | 23 +++++++++++++++
 test/py/tests/test_extension.py | 52 +++++++++++++++++++++++++++++++++
 6 files changed, 96 insertions(+)
 create mode 100644 arch/sandbox/dts/overlay0.dts
 create mode 100644 arch/sandbox/dts/overlay1.dts
 create mode 100644 test/py/tests/test_extension.py

diff --git a/arch/Kconfig b/arch/Kconfig
index 3aa99e08fc..fbe969cce0 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -109,6 +109,7 @@ config SANDBOX
 	select SPI
 	select SUPPORT_OF_CONTROL
 	select SYSRESET_CMD_POWEROFF
+	select SUPPORT_EXTENSION_SCAN
 	imply BITREVERSE
 	select BLOBLIST
 	imply CMD_DM
@@ -146,6 +147,7 @@ config SANDBOX
 	imply ACPI_PMC_SANDBOX
 	imply CMD_PMC
 	imply CMD_CLONE
+	imply CMD_EXTENSION
 
 config SH
 	bool "SuperH architecture"
diff --git a/arch/sandbox/dts/Makefile b/arch/sandbox/dts/Makefile
index d231dc2877..3e5dc67d53 100644
--- a/arch/sandbox/dts/Makefile
+++ b/arch/sandbox/dts/Makefile
@@ -6,6 +6,7 @@ else
 dtb-$(CONFIG_SANDBOX) += sandbox.dtb
 endif
 dtb-$(CONFIG_UT_DM) += test.dtb
+dtb-$(CONFIG_CMD_EXTENSION) += overlay0.dtbo overlay1.dtbo
 
 targets += $(dtb-y)
 
diff --git a/arch/sandbox/dts/overlay0.dts b/arch/sandbox/dts/overlay0.dts
new file mode 100644
index 0000000000..70c6cf77aa
--- /dev/null
+++ b/arch/sandbox/dts/overlay0.dts
@@ -0,0 +1,9 @@
+/dts-v1/;
+/plugin/;
+
+&{/buttons} {
+	btn3 {
+		gpios = <&gpio_a 5 0>;
+		label = "button3";
+	};
+};
diff --git a/arch/sandbox/dts/overlay1.dts b/arch/sandbox/dts/overlay1.dts
new file mode 100644
index 0000000000..51621b3110
--- /dev/null
+++ b/arch/sandbox/dts/overlay1.dts
@@ -0,0 +1,9 @@
+/dts-v1/;
+/plugin/;
+
+&{/buttons} {
+	btn4 {
+		gpios = <&gpio_a 5 0>;
+		label = "button4";
+	};
+};
diff --git a/board/sandbox/sandbox.c b/board/sandbox/sandbox.c
index 18a605de02..6ba1a7177d 100644
--- a/board/sandbox/sandbox.c
+++ b/board/sandbox/sandbox.c
@@ -13,6 +13,9 @@
 #include <os.h>
 #include <asm/test.h>
 #include <asm/u-boot-sandbox.h>
+#include <malloc.h>
+
+#include <extension_board.h>
 
 /*
  * Pointer to initial global data area
@@ -81,6 +84,26 @@ int ft_board_setup(void *fdt, struct bd_info *bd)
 	return fdt_add_mem_rsv(fdt, 0x00d02000, 0x4000);
 }
 
+#ifdef CONFIG_CMD_EXTENSION
+int extension_board_scan(struct list_head *extension_list)
+{
+	struct extension *extension;
+	int i;
+
+	for (i = 0; i < 2; i++) {
+		extension = calloc(1, sizeof(struct extension));
+		snprintf(extension->overlay, sizeof(extension->overlay), "overlay%d.dtbo", i);
+		snprintf(extension->name, sizeof(extension->name), "extension board %d", i);
+		snprintf(extension->owner, sizeof(extension->owner), "sandbox");
+		snprintf(extension->version, sizeof(extension->version), "1.1");
+		snprintf(extension->other, sizeof(extension->other), "Fictionnal extension board");
+		list_add_tail(&extension->list, extension_list);
+	}
+
+	return i;
+}
+#endif
+
 #ifdef CONFIG_BOARD_LATE_INIT
 int board_late_init(void)
 {
diff --git a/test/py/tests/test_extension.py b/test/py/tests/test_extension.py
new file mode 100644
index 0000000000..4712f9bfe3
--- /dev/null
+++ b/test/py/tests/test_extension.py
@@ -0,0 +1,52 @@
+# SPDX-License-Identifier:  GPL-2.0+
+# Copyright (c) 2020
+# Author: Kory Maincent <kory.maincent@bootlin.com>
+
+# Test U-Boot's "extension" commands.
+
+import os
+import pytest
+import u_boot_utils
+
+overlay_addr = 0x1000
+
+SANDBOX_DTB='arch/sandbox/dts/sandbox.dtb'
+OVERLAY_DIR='arch/sandbox/dts/'
+
+def load_dtb(u_boot_console):
+    u_boot_console.log.action('Loading devicetree to RAM...')
+    u_boot_console.run_command('host load hostfs - $fdt_addr_r %s' % (os.path.join(u_boot_console.config.build_dir, SANDBOX_DTB)))
+    u_boot_console.run_command('fdt addr $fdt_addr_r')
+
+ at pytest.mark.buildconfigspec('cmd_fdt')
+def test_extension(u_boot_console):
+    """Test the 'extension' command."""
+
+    load_dtb(u_boot_console)
+
+    output = u_boot_console.run_command('extension list')
+    assert('No extension' in output)
+
+    output = u_boot_console.run_command('extension scan')
+    assert output == 'Found 2 extension board(s).'
+
+    output = u_boot_console.run_command('extension list')
+    assert('overlay0.dtbo' in output)
+    assert('overlay1.dtbo' in output)
+
+    u_boot_console.run_command_list([
+        'setenv extension_overlay_addr %s' % (overlay_addr),
+        'setenv extension_overlay_cmd \'host load hostfs - ${extension_overlay_addr} %s${extension_overlay_name}\'' % (os.path.join(u_boot_console.config.build_dir, OVERLAY_DIR))])
+
+    output = u_boot_console.run_command('extension apply 0')
+    assert('bytes read' in output)
+
+    output = u_boot_console.run_command('fdt print')
+    assert('button3' in output)
+
+    output = u_boot_console.run_command('extension apply all')
+    assert('bytes read' in output)
+
+    output = u_boot_console.run_command('fdt print')
+    assert('button4' in output)
+
-- 
2.17.1

[PATCH 04/10] ti/common: add support for extension_scan_board function

[Kory Maincent]

The BeagleBone platforms all use a common mechanism to discover and
identify extension boards (called "capes"): each extension board has an
I2C-connected EEPROM describing itself.

This patch implements a generic extension_scan_board() feature that can
be used by all BeagleBone platforms to read those I2C EEPROMs and fill
in the list of "extension" structures.

Following commits will enable this common logic on two BeagleBone
platforms.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
---
 board/ti/common/Kconfig       |  3 ++
 board/ti/common/Makefile      |  1 +
 board/ti/common/cape_detect.c | 96 +++++++++++++++++++++++++++++++++++
 board/ti/common/cape_detect.h | 28 ++++++++++
 4 files changed, 128 insertions(+)
 create mode 100644 board/ti/common/cape_detect.c
 create mode 100644 board/ti/common/cape_detect.h

diff --git a/board/ti/common/Kconfig b/board/ti/common/Kconfig
index 9ead7ca038..2e5b852a65 100644
--- a/board/ti/common/Kconfig
+++ b/board/ti/common/Kconfig
@@ -16,6 +16,9 @@ config EEPROM_CHIP_ADDRESS
 	default 0x50
 	depends on TI_I2C_BOARD_DETECT
 
+config CAPE_EEPROM_BUS_NUM
+	int
+
 config TI_COMMON_CMD_OPTIONS
 	bool "Enable cmd options on TI platforms"
 	imply CMD_ASKENV
diff --git a/board/ti/common/Makefile b/board/ti/common/Makefile
index cb97f226ae..3172d87b46 100644
--- a/board/ti/common/Makefile
+++ b/board/ti/common/Makefile
@@ -2,3 +2,4 @@
 # Copyright (C) 2015-2016 Texas Instruments Incorporated - http://www.ti.com/
 
 obj-${CONFIG_TI_I2C_BOARD_DETECT} += board_detect.o
+obj-${CONFIG_CMD_EXTENSION} += cape_detect.o
diff --git a/board/ti/common/cape_detect.c b/board/ti/common/cape_detect.c
new file mode 100644
index 0000000000..2e6105cfbf
--- /dev/null
+++ b/board/ti/common/cape_detect.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2021
+ * K?ry Maincent, Bootlin, <kory.maincent@bootlin.com>
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <i2c.h>
+#include <extension_board.h>
+
+#include "cape_detect.h"
+
+static void sanitize_field(char *text, size_t size)
+{
+	char *c = NULL;
+
+	for (c = text; c < text + (int)size; c++) {
+		if (*c == 0xFF)
+			*c = 0;
+	}
+}
+
+int extension_board_scan(struct list_head *extension_list)
+{
+	struct extension *cape;
+	struct am335x_cape_eeprom_id eeprom_header;
+
+	int num_capes = 0;
+	int ret, i;
+	struct udevice *dev;
+	unsigned char addr;
+
+	char process_cape_part_number[17] = {'0'};
+	char process_cape_version[5] = {'0'};
+	uint8_t cursor = 0;
+
+	for (addr = CAPE_EEPROM_FIRST_ADDR; addr <= CAPE_EEPROM_LAST_ADDR; addr++) {
+		ret = i2c_get_chip_for_busnum(CONFIG_CAPE_EEPROM_BUS_NUM, addr, 1, &dev);
+		if (ret)
+			continue;
+
+		/* Move the read cursor to the beginning of the EEPROM */
+		dm_i2c_write(dev, 0, &cursor, 1);
+		ret = dm_i2c_read(dev, 0, (uint8_t *)&eeprom_header,
+				  sizeof(struct am335x_cape_eeprom_id));
+		if (ret) {
+			printf("Cannot read i2c EEPROM\n");
+			continue;
+		}
+
+		if (eeprom_header.header != CAPE_MAGIC)
+			continue;
+
+		sanitize_field(eeprom_header.board_name, sizeof(eeprom_header.board_name));
+		sanitize_field(eeprom_header.version, sizeof(eeprom_header.version));
+		sanitize_field(eeprom_header.manufacturer, sizeof(eeprom_header.manufacturer));
+		sanitize_field(eeprom_header.part_number, sizeof(eeprom_header.part_number));
+
+		/* Process cape part_number */
+		memset(process_cape_part_number, 0, sizeof(process_cape_part_number));
+		strncpy(process_cape_part_number, eeprom_header.part_number, 16);
+		/* Some capes end with '.' */
+		for (i = 15; i >= 0; i--) {
+			if (process_cape_part_number[i] == '.')
+				process_cape_part_number[i] = '\0';
+			else
+				break;
+		}
+
+		/* Process cape version */
+		memset(process_cape_version, 0, sizeof(process_cape_version));
+		strncpy(process_cape_version, eeprom_header.version, 4);
+		for (i = 0; i < 4; i++) {
+			if (process_cape_version[i] == 0)
+				process_cape_version[i] = '0';
+		}
+
+		printf("BeagleBone Cape: %s (0x%x)\n", eeprom_header.board_name, addr);
+
+		cape = calloc(1, sizeof(struct extension));
+		if (!cape) {
+			printf("Error in memory allocation\n");
+			return num_capes;
+		}
+
+		snprintf(cape->overlay, sizeof(cape->overlay), "%s-%s.dtbo",
+			 process_cape_part_number, process_cape_version);
+		strncpy(cape->name, eeprom_header.board_name, 32);
+		strncpy(cape->version, process_cape_version, 4);
+		strncpy(cape->owner, eeprom_header.manufacturer, 16);
+		list_add_tail(&cape->list, extension_list);
+		num_capes++;
+	}
+	return num_capes;
+}
diff --git a/board/ti/common/cape_detect.h b/board/ti/common/cape_detect.h
new file mode 100644
index 0000000000..b0d5c9f18b
--- /dev/null
+++ b/board/ti/common/cape_detect.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * (C) Copyright 2021
+ * K?ry Maincent, Bootlin, <kory.maincent@bootlin.com>
+ */
+
+#ifndef __CAPE_DETECT_H
+#define __CAPE_DETECT_H
+
+struct am335x_cape_eeprom_id {
+	unsigned int header;
+	char eeprom_rev[2];
+	char board_name[32];
+	char version[4];
+	char manufacturer[16];
+	char part_number[16];
+};
+
+#define CAPE_EEPROM_FIRST_ADDR	0x54
+#define CAPE_EEPROM_LAST_ADDR	0x57
+
+#define CAPE_EEPROM_ADDR_LEN 0x10
+
+#define CAPE_MAGIC 0xEE3355AA
+
+int extension_board_scan(struct list_head *extension_list);
+
+#endif /* __CAPE_DETECT_H */
-- 
2.17.1

[PATCH 05/10] am57xx: add support for cape detect functionality

[Kory Maincent]

This commit enables using the extension board detection mechanism on
AM57xx based platforms.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
---
 arch/arm/mach-omap2/omap5/Kconfig | 1 +
 board/ti/am57xx/board.c           | 1 +
 include/configs/am57xx_evm.h      | 2 ++
 3 files changed, 4 insertions(+)

diff --git a/arch/arm/mach-omap2/omap5/Kconfig b/arch/arm/mach-omap2/omap5/Kconfig
index a7132dae09..4c2f990b28 100644
--- a/arch/arm/mach-omap2/omap5/Kconfig
+++ b/arch/arm/mach-omap2/omap5/Kconfig
@@ -36,6 +36,7 @@ config TARGET_AM57XX_EVM
 	select CMD_DDR3
 	select DRA7XX
 	select TI_I2C_BOARD_DETECT
+	select SUPPORT_EXTENSION_SCAN
 	imply DM_THERMAL
 	imply SCSI
 	imply SPL_THERMAL
diff --git a/board/ti/am57xx/board.c b/board/ti/am57xx/board.c
index 7809875510..a2df4def78 100644
--- a/board/ti/am57xx/board.c
+++ b/board/ti/am57xx/board.c
@@ -42,6 +42,7 @@
 #include <hang.h>
 
 #include "../common/board_detect.h"
+#include "../common/cape_detect.h"
 #include "mux_data.h"
 
 #ifdef CONFIG_SUPPORT_EMMC_BOOT
diff --git a/include/configs/am57xx_evm.h b/include/configs/am57xx_evm.h
index c47ffccff1..0413d171c4 100644
--- a/include/configs/am57xx_evm.h
+++ b/include/configs/am57xx_evm.h
@@ -26,6 +26,8 @@
 #define CONFIG_SYS_I2C_EEPROM_ADDR	0x50	/* Main EEPROM */
 #define CONFIG_SYS_I2C_EEPROM_ADDR_LEN	2
 
+#define CONFIG_CAPE_EEPROM_BUS_NUM	3
+
 #define CONFIG_SYS_OMAP_ABE_SYSCK
 
 #ifndef CONFIG_SPL_BUILD
-- 
2.17.1

[PATCH 06/10] arm: dts: sun5i: enable one-wire on the CHIP

[Kory Maincent]

Add the EEPROM description in the devicetree for the CHIP board.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
---
 arch/arm/dts/sun5i-r8-chip.dts | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm/dts/sun5i-r8-chip.dts b/arch/arm/dts/sun5i-r8-chip.dts
index 879a4b0f3b..d915eb3eb7 100644
--- a/arch/arm/dts/sun5i-r8-chip.dts
+++ b/arch/arm/dts/sun5i-r8-chip.dts
@@ -89,6 +89,12 @@
 		gpios = <&pio 3 2 GPIO_ACTIVE_HIGH>; /* PD2 */
 		pinctrl-names = "default";
 		pinctrl-0 = <&chip_w1_pin>;
+
+		w1_eeprom: w1_eeprom at 0 {
+			compatible = "maxim,ds2431";
+			status = "okay";
+		};
+
 	};
 };
 
-- 
2.17.1

[PATCH 07/10] arm: mach-sunxi: add CHIP board target

[Kory Maincent]

The CHIP board use one-wire EEPROM to discover and identify extension
boards (called "DIPs").

This commit add the configuration for the CHIP board target to enable the
EEPROM one-wire driver.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
---

Need the following patches series to fix a one-wire gpio issue.
https://lists.denx.de/pipermail/u-boot/2021-February/440073.html

 arch/arm/mach-sunxi/Kconfig | 14 ++++++++++++++
 configs/CHIP_defconfig      |  1 +
 2 files changed, 15 insertions(+)

diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
index 49ef217f08..37a4294d88 100644
--- a/arch/arm/mach-sunxi/Kconfig
+++ b/arch/arm/mach-sunxi/Kconfig
@@ -1,5 +1,19 @@
 if ARCH_SUNXI
 
+choice
+	prompt "Sunxi board select"
+	optional
+
+config TARGET_CHIP
+	bool "CHIP board"
+	select W1
+	select W1_GPIO
+	select W1_EEPROM
+	select W1_EEPROM_DS24XXX
+
+endchoice
+
+
 config SPL_LDSCRIPT
 	default "arch/arm/cpu/armv7/sunxi/u-boot-spl.lds" if !ARM64
 
diff --git a/configs/CHIP_defconfig b/configs/CHIP_defconfig
index a70ee31d40..6810797b19 100644
--- a/configs/CHIP_defconfig
+++ b/configs/CHIP_defconfig
@@ -1,6 +1,7 @@
 CONFIG_ARM=y
 CONFIG_ARCH_SUNXI=y
 CONFIG_SPL=y
+CONFIG_TARGET_CHIP=y
 CONFIG_MACH_SUN5I=y
 CONFIG_DRAM_TIMINGS_DDR3_800E_1066G_1333J=y
 CONFIG_USB0_VBUS_PIN="PB10"
-- 
2.17.1

[PATCH 08/10] sun5i: add support for DIP detection to CHIP board

[Kory Maincent]

Add the extension_board_scan specific function to scan the information
of the EEPROM on one-wire and fill the extension struct.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
---
 arch/arm/mach-sunxi/Kconfig |   2 +
 board/sunxi/Makefile        |   1 +
 board/sunxi/chip.c          | 104 ++++++++++++++++++++++++++++++++++++
 3 files changed, 107 insertions(+)
 create mode 100644 board/sunxi/chip.c

diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
index 37a4294d88..3bb8a08b34 100644
--- a/arch/arm/mach-sunxi/Kconfig
+++ b/arch/arm/mach-sunxi/Kconfig
@@ -6,10 +6,12 @@ choice
 
 config TARGET_CHIP
 	bool "CHIP board"
+	select SUPPORT_EXTENSION_SCAN
 	select W1
 	select W1_GPIO
 	select W1_EEPROM
 	select W1_EEPROM_DS24XXX
+	imply CMD_EXTENSION
 
 endchoice
 
diff --git a/board/sunxi/Makefile b/board/sunxi/Makefile
index c4e13f8c38..e6dcc9fca5 100644
--- a/board/sunxi/Makefile
+++ b/board/sunxi/Makefile
@@ -11,3 +11,4 @@ obj-$(CONFIG_SUN7I_GMAC)	+= gmac.o
 obj-$(CONFIG_MACH_SUN4I)	+= dram_sun4i_auto.o
 obj-$(CONFIG_MACH_SUN5I)	+= dram_sun5i_auto.o
 obj-$(CONFIG_MACH_SUN7I)	+= dram_sun5i_auto.o
+obj-$(CONFIG_TARGET_CHIP)	+= chip.o
diff --git a/board/sunxi/chip.c b/board/sunxi/chip.c
new file mode 100644
index 0000000000..fc3d14e497
--- /dev/null
+++ b/board/sunxi/chip.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2021
+ * K?ry Maincent, Bootlin, <kory.maincent@bootlin.com>
+ * Based on initial code from Maxime Ripard
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <dm.h>
+#include <w1.h>
+#include <w1-eeprom.h>
+#include <dm/device-internal.h>
+
+#include <asm/arch/gpio.h>
+
+#include <extension_board.h>
+
+#ifdef CONFIG_CMD_EXTENSION
+
+#define for_each_1w_device(b, d) \
+	for (device_find_first_child(b, d); *d; device_find_next_child(d))
+
+#define dip_convert(field)						\
+	(								\
+		(sizeof(field) == 1) ? field :				\
+		(sizeof(field) == 2) ? be16_to_cpu(field) :		\
+		(sizeof(field) == 4) ? be32_to_cpu(field) :		\
+		-1							\
+	)
+
+#define DIP_MAGIC	0x50494843	/* CHIP */
+
+struct dip_w1_header {
+	u32     magic;                  /* CHIP */
+	u8      version;                /* spec version */
+	u32     vendor_id;
+	u16     product_id;
+	u8      product_version;
+	char    vendor_name[32];
+	char    product_name[32];
+	u8      rsvd[36];               /* rsvd for future spec versions */
+	u8      data[16];               /* user data, per-dip specific */
+} __packed;
+
+int extension_board_scan(struct list_head *extension_list)
+{
+	struct extension *dip;
+	struct dip_w1_header w1_header;
+	struct udevice *bus, *dev;
+	u32 vid;
+	u16 pid;
+	int ret;
+
+	int num_dip = 0;
+
+	sunxi_gpio_set_pull(SUNXI_GPD(2), SUNXI_GPIO_PULL_UP);
+
+	ret = w1_get_bus(0, &bus);
+	if (ret) {
+		printf("one wire interface not found\n");
+		return 0;
+	}
+
+	for_each_1w_device(bus, &dev) {
+		if (w1_get_device_family(dev) != W1_FAMILY_DS2431)
+			continue;
+
+		ret = device_probe(dev);
+		if (ret) {
+			printf("Couldn't probe device %s: error %d",
+			       dev->name, ret);
+			continue;
+		}
+
+		w1_eeprom_read_buf(dev, 0, (u8 *)&w1_header, sizeof(w1_header));
+
+		if (w1_header.magic != DIP_MAGIC)
+			continue;
+
+		vid = dip_convert(w1_header.vendor_id);
+		pid = dip_convert(w1_header.product_id);
+
+		printf("DIP: %s (0x%x) from %s (0x%x)\n",
+		       w1_header.product_name, pid,
+		       w1_header.vendor_name, vid);
+
+		dip = calloc(1, sizeof(struct extension));
+		if (!dip) {
+			printf("Error in memory allocation\n");
+			return num_dip;
+		}
+
+		snprintf(dip->overlay, sizeof(dip->overlay), "dip-%x-%x.dtbo",
+			 vid, pid);
+		strncpy(dip->name, w1_header.product_name, 32);
+		strncpy(dip->owner, w1_header.vendor_name, 32);
+		list_add_tail(&dip->list, extension_list);
+		num_dip++;
+	}
+	return num_dip;
+}
+
+#endif /* CONFIG_CMD_EXTENSION */
-- 
2.17.1

[PATCH 09/10] arm: am335x: add support for i2c2 bus

[Kory Maincent]

The am335x from BeagleBone use i2c EEPROM to detect capes.
The memory is wired to i2c bus 2 therefore it need to be enabled.

Add i2c2 clock, pinmux description and pinmux enable function.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
---
 arch/arm/mach-omap2/am33xx/clock_am33xx.c |  1 +
 board/ti/am335x/board.c                   |  2 ++
 board/ti/am335x/board.h                   |  1 +
 board/ti/am335x/mux.c                     | 15 +++++++++++++++
 4 files changed, 19 insertions(+)

diff --git a/arch/arm/mach-omap2/am33xx/clock_am33xx.c b/arch/arm/mach-omap2/am33xx/clock_am33xx.c
index 2427933c8b..7c67444024 100644
--- a/arch/arm/mach-omap2/am33xx/clock_am33xx.c
+++ b/arch/arm/mach-omap2/am33xx/clock_am33xx.c
@@ -220,6 +220,7 @@ void enable_basic_clocks(void)
 		&cmper->gpio2clkctrl,
 		&cmper->gpio3clkctrl,
 		&cmper->i2c1clkctrl,
+		&cmper->i2c2clkctrl,
 		&cmper->cpgmac0clkctrl,
 		&cmper->spi0clkctrl,
 		&cmrtc->rtcclkctrl,
diff --git a/board/ti/am335x/board.c b/board/ti/am335x/board.c
index 984cc5e3ba..56cdda856c 100644
--- a/board/ti/am335x/board.c
+++ b/board/ti/am335x/board.c
@@ -76,8 +76,10 @@ static struct ctrl_dev *cdev = (struct ctrl_dev *)CTRL_DEVICE_BASE;
 void do_board_detect(void)
 {
 	enable_i2c0_pin_mux();
+	enable_i2c2_pin_mux();
 #ifndef CONFIG_DM_I2C
 	i2c_init(CONFIG_SYS_OMAP24_I2C_SPEED, CONFIG_SYS_OMAP24_I2C_SLAVE);
+	i2c_init(CONFIG_SYS_OMAP24_I2C_SPEED2, CONFIG_SYS_OMAP24_I2C_SLAVE2);
 #endif
 	if (ti_i2c_eeprom_am_get(CONFIG_EEPROM_BUS_ADDRESS,
 				 CONFIG_EEPROM_CHIP_ADDRESS))
diff --git a/board/ti/am335x/board.h b/board/ti/am335x/board.h
index 48df914af9..c2962111c1 100644
--- a/board/ti/am335x/board.h
+++ b/board/ti/am335x/board.h
@@ -93,5 +93,6 @@ void enable_uart3_pin_mux(void);
 void enable_uart4_pin_mux(void);
 void enable_uart5_pin_mux(void);
 void enable_i2c0_pin_mux(void);
+void enable_i2c2_pin_mux(void);
 void enable_board_pin_mux(void);
 #endif
diff --git a/board/ti/am335x/mux.c b/board/ti/am335x/mux.c
index 6fb2c009ba..78dc0cca42 100644
--- a/board/ti/am335x/mux.c
+++ b/board/ti/am335x/mux.c
@@ -124,6 +124,14 @@ static struct module_pin_mux i2c1_pin_mux[] = {
 	{-1},
 };
 
+static struct module_pin_mux i2c2_pin_mux[] = {
+	{OFFSET(uart1_ctsn), (MODE(3) | RXACTIVE |
+			PULLUDEN | PULLUP_EN | SLEWCTRL)},	/* I2C_DATA */
+	{OFFSET(uart1_rtsn), (MODE(3) | RXACTIVE |
+			PULLUDEN | PULLUP_EN | SLEWCTRL)},	/* I2C_SCLK */
+	{-1},
+};
+
 static struct module_pin_mux spi0_pin_mux[] = {
 	{OFFSET(spi0_sclk), (MODE(0) | RXACTIVE | PULLUDEN)},	/* SPI0_SCLK */
 	{OFFSET(spi0_d0), (MODE(0) | RXACTIVE |
@@ -308,6 +316,11 @@ void enable_i2c0_pin_mux(void)
 	configure_module_pin_mux(i2c0_pin_mux);
 }
 
+void enable_i2c2_pin_mux(void)
+{
+	configure_module_pin_mux(i2c2_pin_mux);
+}
+
 /*
  * The AM335x GP EVM, if daughter card(s) are connected, can have 8
  * different profiles.  These profiles determine what peripherals are
@@ -367,6 +380,7 @@ void enable_board_pin_mux(void)
 #else
 		configure_module_pin_mux(mmc1_pin_mux);
 #endif
+		configure_module_pin_mux(i2c2_pin_mux);
 	} else if (board_is_gp_evm()) {
 		/* General Purpose EVM */
 		unsigned short profile = detect_daughter_board_profile();
@@ -411,6 +425,7 @@ void enable_board_pin_mux(void)
 #else
 		configure_module_pin_mux(mmc1_pin_mux);
 #endif
+		configure_module_pin_mux(i2c2_pin_mux);
 	} else if (board_is_pb()) {
 		configure_module_pin_mux(mii1_pin_mux);
 		configure_module_pin_mux(mmc0_pin_mux);
-- 
2.17.1

[PATCH 10/10] am335x: add support for cape detect functionality

[Kory Maincent]

Update the Kconfig and the board file to make the am335x board compatible
with cape detection.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
---
 arch/arm/mach-omap2/am33xx/Kconfig | 1 +
 board/ti/am335x/board.c            | 1 +
 include/configs/am335x_evm.h       | 2 ++
 3 files changed, 4 insertions(+)

diff --git a/arch/arm/mach-omap2/am33xx/Kconfig b/arch/arm/mach-omap2/am33xx/Kconfig
index 9a98e8a0a9..11e54cd293 100644
--- a/arch/arm/mach-omap2/am33xx/Kconfig
+++ b/arch/arm/mach-omap2/am33xx/Kconfig
@@ -34,6 +34,7 @@ config TARGET_AM335X_EVM
 	select DM_GPIO
 	select DM_SERIAL
 	select TI_I2C_BOARD_DETECT
+	select SUPPORT_EXTENSION_SCAN
 	imply CMD_DM
 	imply SPL_DM
 	imply SPL_DM_SEQ_ALIAS
diff --git a/board/ti/am335x/board.c b/board/ti/am335x/board.c
index 56cdda856c..eb5cbd3b30 100644
--- a/board/ti/am335x/board.c
+++ b/board/ti/am335x/board.c
@@ -43,6 +43,7 @@
 #include <env_internal.h>
 #include <watchdog.h>
 #include "../common/board_detect.h"
+#include "../common/cape_detect.h"
 #include "board.h"
 
 DECLARE_GLOBAL_DATA_PTR;
diff --git a/include/configs/am335x_evm.h b/include/configs/am335x_evm.h
index 5af90d932d..65835e094d 100644
--- a/include/configs/am335x_evm.h
+++ b/include/configs/am335x_evm.h
@@ -188,6 +188,8 @@
 #define CONFIG_SYS_I2C_EEPROM_ADDR	0x50	/* Main EEPROM */
 #define CONFIG_SYS_I2C_EEPROM_ADDR_LEN	2
 
+#define CONFIG_CAPE_EEPROM_BUS_NUM	2
+
 /* PMIC support */
 #define CONFIG_POWER_TPS65217
 #define CONFIG_POWER_TPS65910
-- 
2.17.1

[PATCH 01/10] fdt_support: move fdt_valid from cmd_fdt.c to fdt_support.c

[Tom Rini]

On Thu, Feb 18, 2021 at 02:29:29PM +0100, Kory Maincent wrote:

> Move the fdt_valid function to fdt_support.
> This changes allow to be able to test the validity of a devicetree in
> other c files.
> 
> Update code syntax.
> 
> Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>

Reviewed-by: Tom Rini <trini@konsulko.com>

-- 
Tom
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[PATCH 02/10] cmd: add support for a new "extension" command

[Tom Rini]

On Thu, Feb 18, 2021 at 02:29:30PM +0100, Kory Maincent wrote:

> This patch adds a new "extension" command, which aims at detecting
> extension boards connected to the hardware platform, and apply the
> Device Tree overlays that describe the hardware present on those
> extension boards.
> 
> In order to enable this mechanism, board-specific code must implement
> the extension_board_scan() function that fills in a linked list of
> "struct extension", each describing one extension board. In addition,
> the board-specific code must select the SUPPORT_EXTENSION_SCAN Kconfig
> boolean.
[snip]
>  doc/README.extension      |  80 ++++++++++++++++++

This should be rST and under docs/ somewhere.

[snip]
> +		puts(
> +			"No FDT memory address configured. Please configure\n"
> +			"the FDT address via \"fdt addr <address>\" command.\n");

This should be a printf() and line-formatted correctly so checkpatch.pl
doesn't complain.  Thanks!

-- 
Tom
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[PATCH 06/10] arm: dts: sun5i: enable one-wire on the CHIP

[Tom Rini]

On Thu, Feb 18, 2021 at 02:29:34PM +0100, Kory Maincent wrote:
> Add the EEPROM description in the devicetree for the CHIP board.
> 
> Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
> ---
>  arch/arm/dts/sun5i-r8-chip.dts | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/arch/arm/dts/sun5i-r8-chip.dts b/arch/arm/dts/sun5i-r8-chip.dts
> index 879a4b0f3b..d915eb3eb7 100644
> --- a/arch/arm/dts/sun5i-r8-chip.dts
> +++ b/arch/arm/dts/sun5i-r8-chip.dts
> @@ -89,6 +89,12 @@
>  		gpios = <&pio 3 2 GPIO_ACTIVE_HIGH>; /* PD2 */
>  		pinctrl-names = "default";
>  		pinctrl-0 = <&chip_w1_pin>;
> +
> +		w1_eeprom: w1_eeprom at 0 {
> +			compatible = "maxim,ds2431";
> +			status = "okay";
> +		};
> +
>  	};
>  };

This should be in, or re-synced from, the Linux dts file.

-- 
Tom
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[PATCH 07/10] arm: mach-sunxi: add CHIP board target

[Tom Rini]

On Thu, Feb 18, 2021 at 02:29:35PM +0100, Kory Maincent wrote:
> The CHIP board use one-wire EEPROM to discover and identify extension
> boards (called "DIPs").
> 
> This commit add the configuration for the CHIP board target to enable the
> EEPROM one-wire driver.
> 
> Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
> ---
> 
> Need the following patches series to fix a one-wire gpio issue.
> https://lists.denx.de/pipermail/u-boot/2021-February/440073.html
> 
>  arch/arm/mach-sunxi/Kconfig | 14 ++++++++++++++
>  configs/CHIP_defconfig      |  1 +
>  2 files changed, 15 insertions(+)
> 
> diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
> index 49ef217f08..37a4294d88 100644
> --- a/arch/arm/mach-sunxi/Kconfig
> +++ b/arch/arm/mach-sunxi/Kconfig
> @@ -1,5 +1,19 @@
>  if ARCH_SUNXI
>  
> +choice
> +	prompt "Sunxi board select"
> +	optional
> +
> +config TARGET_CHIP
> +	bool "CHIP board"
> +	select W1
> +	select W1_GPIO
> +	select W1_EEPROM
> +	select W1_EEPROM_DS24XXX
> +
> +endchoice
> +
> +
>  config SPL_LDSCRIPT
>  	default "arch/arm/cpu/armv7/sunxi/u-boot-spl.lds" if !ARM64
>  
> diff --git a/configs/CHIP_defconfig b/configs/CHIP_defconfig
> index a70ee31d40..6810797b19 100644
> --- a/configs/CHIP_defconfig
> +++ b/configs/CHIP_defconfig
> @@ -1,6 +1,7 @@
>  CONFIG_ARM=y
>  CONFIG_ARCH_SUNXI=y
>  CONFIG_SPL=y
> +CONFIG_TARGET_CHIP=y
>  CONFIG_MACH_SUN5I=y
>  CONFIG_DRAM_TIMINGS_DDR3_800E_1066G_1333J=y
>  CONFIG_USB0_VBUS_PIN="PB10"

I think you should really just be adding options to the defconfig
directly, sunxi has been avoiding adding TARGET_xxx options.

-- 
Tom
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[PATCH 08/10] sun5i: add support for DIP detection to CHIP board

[Tom Rini]

On Thu, Feb 18, 2021 at 02:29:36PM +0100, Kory Maincent wrote:

> Add the extension_board_scan specific function to scan the information
> of the EEPROM on one-wire and fill the extension struct.
> 
> Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
> ---
>  arch/arm/mach-sunxi/Kconfig |   2 +
>  board/sunxi/Makefile        |   1 +
>  board/sunxi/chip.c          | 104 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 107 insertions(+)
>  create mode 100644 board/sunxi/chip.c
> 
> diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
> index 37a4294d88..3bb8a08b34 100644
> --- a/arch/arm/mach-sunxi/Kconfig
> +++ b/arch/arm/mach-sunxi/Kconfig
> @@ -6,10 +6,12 @@ choice
>  
>  config TARGET_CHIP
>  	bool "CHIP board"
> +	select SUPPORT_EXTENSION_SCAN
>  	select W1
>  	select W1_GPIO
>  	select W1_EEPROM
>  	select W1_EEPROM_DS24XXX
> +	imply CMD_EXTENSION

And then based on my comment in the previous patch, similar to
PINEPHONE_DT_SELECTION and other board-specific options, add a
CHIP_DIP_SCAN option or similar.

-- 
Tom
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[PATCH 10/10] am335x: add support for cape detect functionality

[Tom Rini]

On Thu, Feb 18, 2021 at 02:29:38PM +0100, Kory Maincent wrote:

> Update the Kconfig and the board file to make the am335x board compatible
> with cape detection.
> 
> Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
> ---
>  arch/arm/mach-omap2/am33xx/Kconfig | 1 +
>  board/ti/am335x/board.c            | 1 +
>  include/configs/am335x_evm.h       | 2 ++
>  3 files changed, 4 insertions(+)
[snip]
> +#define CONFIG_CAPE_EEPROM_BUS_NUM	2

You can't add new CONFIG options like that outside of Kconfig.

-- 
Tom
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[PATCH 08/10] sun5i: add support for DIP detection to CHIP board

[Andre Przywara]

On Fri, 19 Feb 2021 11:54:54 -0500
Tom Rini <trini@konsulko.com> wrote:

Hi,

> On Thu, Feb 18, 2021 at 02:29:36PM +0100, Kory Maincent wrote:
> 
> > Add the extension_board_scan specific function to scan the information
> > of the EEPROM on one-wire and fill the extension struct.
> > 
> > Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
> > ---
> >  arch/arm/mach-sunxi/Kconfig |   2 +
> >  board/sunxi/Makefile        |   1 +
> >  board/sunxi/chip.c          | 104 ++++++++++++++++++++++++++++++++++++
> >  3 files changed, 107 insertions(+)
> >  create mode 100644 board/sunxi/chip.c
> > 
> > diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
> > index 37a4294d88..3bb8a08b34 100644
> > --- a/arch/arm/mach-sunxi/Kconfig
> > +++ b/arch/arm/mach-sunxi/Kconfig
> > @@ -6,10 +6,12 @@ choice
> >  
> >  config TARGET_CHIP
> >  	bool "CHIP board"
> > +	select SUPPORT_EXTENSION_SCAN
> >  	select W1
> >  	select W1_GPIO
> >  	select W1_EEPROM
> >  	select W1_EEPROM_DS24XXX
> > +	imply CMD_EXTENSION  
> 
> And then based on my comment in the previous patch, similar to
> PINEPHONE_DT_SELECTION and other board-specific options, add a
> CHIP_DIP_SCAN option or similar.

Yes, indeed, thanks Tom.

The idea of making this extension scheme generic is great, it's just
that sunxi is using a different approach to board specific code here.
Normally we expect U-Boot-proper board specific code to be DT driven,
and where this does not really work, use those symbols that Tom pointed
to.

Thanks,
Andre

[PATCH 08/10] sun5i: add support for DIP detection to CHIP board

[Köry Maincent]

Hi Tom, Andre

Thanks for your reviews.

On Fri, 19 Feb 2021 17:29:26 +0000
Andre Przywara <andre.przywara@arm.com> wrote:

> > 
> > And then based on my comment in the previous patch, similar to
> > PINEPHONE_DT_SELECTION and other board-specific options, add a
> > CHIP_DIP_SCAN option or similar.  
> 
> Yes, indeed, thanks Tom.
> 
> The idea of making this extension scheme generic is great, it's just
> that sunxi is using a different approach to board specific code here.
> Normally we expect U-Boot-proper board specific code to be DT driven,
> and where this does not really work, use those symbols that Tom pointed
> to.

For my extension_board_scan board specific function, would you prefer if I move
to callback like below instead of Kconfig?

if (of_machine_is_compatible("nextthing,chip"))
	extension_board_register_callback(chip_extension_board_scan);

Regards,
K?ry

[PATCH 08/10] sun5i: add support for DIP detection to CHIP board

[Andre Przywara]

On Mon, 22 Feb 2021 15:23:08 +0100
K?ry Maincent <kory.maincent@bootlin.com> wrote:

Hi K?ry,

> Thanks for your reviews.
> 
> On Fri, 19 Feb 2021 17:29:26 +0000
> Andre Przywara <andre.przywara@arm.com> wrote:
> 
> > > 
> > > And then based on my comment in the previous patch, similar to
> > > PINEPHONE_DT_SELECTION and other board-specific options, add a
> > > CHIP_DIP_SCAN option or similar.    
> > 
> > Yes, indeed, thanks Tom.
> > 
> > The idea of making this extension scheme generic is great, it's just
> > that sunxi is using a different approach to board specific code here.
> > Normally we expect U-Boot-proper board specific code to be DT driven,
> > and where this does not really work, use those symbols that Tom pointed
> > to.  
> 
> For my extension_board_scan board specific function, would you prefer if I move
> to callback like below instead of Kconfig?
> 
> if (of_machine_is_compatible("nextthing,chip"))
> 	extension_board_register_callback(chip_extension_board_scan);

Well, the CHIP Pro uses a different compatible string, so you would
need to check for that too.
I am not fully decided if checking for the machine compatible is the
right approach. The more traditional U-Boot way would be to define a
config symbol (as Tom already pointed out), that would also keep the
code out of other board builds.
We do this already with CONFIG_PINE64_DT_SELECTION and
CONFIG_PINEPHONE_DT_SELECTION.

Cheers,
Andre

[PATCH 08/10] sun5i: add support for DIP detection to CHIP board

[Köry Maincent]

Hello Andre,

On Tue, 23 Feb 2021 13:30:38 +0000
Andre Przywara <andre.przywara@arm.com> wrote:
y extension_board_scan board specific function, would you prefer if I
> > move to callback like below instead of Kconfig?
> > 
> > if (of_machine_is_compatible("nextthing,chip"))
> > 	extension_board_register_callback(chip_extension_board_scan);  
> 
> Well, the CHIP Pro uses a different compatible string, so you would
> need to check for that too.
> I am not fully decided if checking for the machine compatible is the
> right approach. The more traditional U-Boot way would be to define a
> config symbol (as Tom already pointed out), that would also keep the
> code out of other board builds.
> We do this already with CONFIG_PINE64_DT_SELECTION and
> CONFIG_PINEPHONE_DT_SELECTION.

Okay, I will move on to the traditional config symbol.

Thanks.

K?ry