[U-Boot] [PATCH v2 1/3] drivers: Add board uclass
Mario Six
mario.six at gdsys.cc
Fri Apr 27 12:51:32 UTC 2018
Since there is no canonical "board device" that can be used in board
files, it is difficult to use DM function for board initialization in
these cases.
Hence, add a uclass that implements a simple "board device", which can
hold devices not suitable anywhere else in the device tree, and is also
able to read encoded information, e.g. hard-wired GPIOs on a GPIO
expander, read-only memory ICs, etc. that carry information about the
hardware.
The devices of this uclass expose methods to read generic data types
(integers, strings, booleans) to encode the information provided by the
hardware.
Signed-off-by: Mario Six <mario.six at gdsys.cc>
---
v1 -> v2:
* Corrected description of dev parameter of devinfo_detect
* Added size parameter to devinfo_get_str
* Expanded uclass documentation
* Added function to get devinfo instance
* Renamed the uclass from devinfo to board
---
drivers/Kconfig | 2 +
drivers/Makefile | 1 +
drivers/board/Kconfig | 17 +++++++
drivers/board/Makefile | 9 ++++
drivers/board/board-uclass.c | 61 +++++++++++++++++++++++
include/board.h | 115 +++++++++++++++++++++++++++++++++++++++++++
include/dm/uclass-id.h | 1 +
7 files changed, 206 insertions(+)
create mode 100644 drivers/board/Kconfig
create mode 100644 drivers/board/Makefile
create mode 100644 drivers/board/board-uclass.c
create mode 100644 include/board.h
diff --git a/drivers/Kconfig b/drivers/Kconfig
index c2e813f5ad..19c7c448c0 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -22,6 +22,8 @@ source "drivers/ddr/Kconfig"
source "drivers/demo/Kconfig"
+source "drivers/board/Kconfig"
+
source "drivers/ddr/fsl/Kconfig"
source "drivers/dfu/Kconfig"
diff --git a/drivers/Makefile b/drivers/Makefile
index 6846d181aa..fecf64021c 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -72,6 +72,7 @@ obj-y += block/
obj-$(CONFIG_BOOTCOUNT_LIMIT) += bootcount/
obj-$(CONFIG_CPU) += cpu/
obj-y += crypto/
+obj-y += board/
obj-y += firmware/
obj-$(CONFIG_FPGA) += fpga/
obj-y += misc/
diff --git a/drivers/board/Kconfig b/drivers/board/Kconfig
new file mode 100644
index 0000000000..cc1cf27205
--- /dev/null
+++ b/drivers/board/Kconfig
@@ -0,0 +1,17 @@
+menuconfig BOARD
+ bool "Device Information"
+ help
+ Support methods to query hardware configurations from internal
+ mechanisms (e.g. reading GPIO values, determining the presence of
+ devices on busses, etc.). This enables the usage of U-Boot with
+ modular board architectures.
+
+if BOARD
+
+
+config BOARD_GAZERBEAM
+ bool "Enable device information for the Gazerbeam board"
+ help
+ Support querying device information for the gdsys Gazerbeam board.
+
+endif
diff --git a/drivers/board/Makefile b/drivers/board/Makefile
new file mode 100644
index 0000000000..397706245a
--- /dev/null
+++ b/drivers/board/Makefile
@@ -0,0 +1,9 @@
+#
+# (C) Copyright 2017
+# Mario Six, Guntermann & Drunck GmbH, mario.six at gdsys.cc
+#
+# SPDX-License-Identifier: GPL-2.0+
+#
+
+obj-$(CONFIG_BOARD) += board-uclass.o
+obj-$(CONFIG_BOARD_GAZERBEAM) += gazerbeam.o
diff --git a/drivers/board/board-uclass.c b/drivers/board/board-uclass.c
new file mode 100644
index 0000000000..3137437245
--- /dev/null
+++ b/drivers/board/board-uclass.c
@@ -0,0 +1,61 @@
+/*
+ * (C) Copyright 2017
+ * Mario Six, Guntermann & Drunck GmbH, mario.six at gdsys.cc
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <board.h>
+
+int get_board(struct udevice **devp)
+{
+ return uclass_first_device_err(UCLASS_BOARD, devp);
+}
+
+int board_detect(struct udevice *dev)
+{
+ struct board_ops *ops = board_get_ops(dev);
+
+ if (!ops->detect)
+ return -ENOSYS;
+
+ return ops->detect(dev);
+}
+
+int board_get_bool(struct udevice *dev, int id, bool *val)
+{
+ struct board_ops *ops = board_get_ops(dev);
+
+ if (!ops->get_bool)
+ return -ENOSYS;
+
+ return ops->get_bool(dev, id, val);
+}
+
+int board_get_int(struct udevice *dev, int id, int *val)
+{
+ struct board_ops *ops = board_get_ops(dev);
+
+ if (!ops->get_int)
+ return -ENOSYS;
+
+ return ops->get_int(dev, id, val);
+}
+
+int board_get_str(struct udevice *dev, int id, size_t size, char *val)
+{
+ struct board_ops *ops = board_get_ops(dev);
+
+ if (!ops->get_str)
+ return -ENOSYS;
+
+ return ops->get_str(dev, id, size, val);
+}
+
+UCLASS_DRIVER(board) = {
+ .id = UCLASS_BOARD,
+ .name = "board",
+ .post_bind = dm_scan_fdt_dev,
+};
diff --git a/include/board.h b/include/board.h
new file mode 100644
index 0000000000..0e64a3dfce
--- /dev/null
+++ b/include/board.h
@@ -0,0 +1,115 @@
+/*
+ * (C) Copyright 2017
+ * Mario Six, Guntermann & Drunck GmbH, mario.six at gdsys.cc
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+/**
+ * This uclass encapsulates hardware methods to gather information about a
+ * board or a specific device such as hard-wired GPIOs on GPIO expanders,
+ * read-only data in flash ICs, or similar.
+ *
+ * The interface offers functions to read the usual standard data types (bool,
+ * int, string) from the device, each of which is identified by a static
+ * numeric ID (which will usually be defined as a enum in a header file).
+ *
+ * If for example dev was a board device representing a read-only serial
+ * number flash IC, we could call
+ *
+ * board_detect(dev);
+ * board_get_int(dev, ID_SERIAL_NUMBER, &serial);
+ *
+ * to read the serial number from the device.
+ */
+
+struct board_ops {
+ /**
+ * detect() - Run the hardware info detection procedure for this
+ * device.
+ *
+ * @dev: The device containing the information
+ * @return 0 if OK, -ve on error.
+ */
+ int (*detect)(struct udevice *dev);
+
+ /**
+ * get_bool() - Read a specific bool data value that describes the
+ * hardware setup.
+ *
+ * @dev: The board instance to gather the data.
+ * @id: A unique identifier for the bool value to be read.
+ * @val: Pointer to a buffer that receives the value read.
+ * @return 0 if OK, -ve on error.
+ */
+ int (*get_bool)(struct udevice *dev, int id, bool *val);
+
+ /**
+ * get_int() - Read a specific int data value that describes the
+ * hardware setup.
+ *
+ * @dev: The board instance to gather the data.
+ * @id: A unique identifier for the int value to be read.
+ * @val: Pointer to a buffer that receives the value read.
+ * @return 0 if OK, -ve on error.
+ */
+ int (*get_int)(struct udevice *dev, int id, int *val);
+
+ /**
+ * get_str() - Read a specific string data value that describes the
+ * hardware setup.
+ *
+ * @dev: The board instance to gather the data.
+ * @id: A unique identifier for the string value to be read.
+ * @size: The size of the buffer to receive the string data.
+ * @val: Pointer to a buffer that receives the value read.
+ * @return 0 if OK, -ve on error.
+ */
+ int (*get_str)(struct udevice *dev, int id, size_t size, char *val);
+};
+
+#define board_get_ops(dev) ((struct board_ops *)(dev)->driver->ops)
+
+/**
+ * board_detect() - Run the hardware info detection procedure for this device.
+ *
+ * @dev: The device containing the information
+ * @return 0 if OK, -ve on error.
+ */
+int board_detect(struct udevice *dev);
+
+/**
+ * board_get_bool() - Read a specific bool data value that describes the
+ * hardware setup.
+ *
+ * @dev: The board instance to gather the data.
+ * @id: A unique identifier for the bool value to be read.
+ * @val: Pointer to a buffer that receives the value read.
+ * @return 0 if OK, -ve on error.
+ */
+int board_get_bool(struct udevice *dev, int id, bool *val);
+
+/**
+ * board_get_int() - Read a specific int data value that describes the
+ * hardware setup.
+ *
+ * @dev: The board instance to gather the data.
+ * @id: A unique identifier for the int value to be read.
+ * @val: Pointer to a buffer that receives the value read.
+ * @return 0 if OK, -ve on error.
+ */
+int board_get_int(struct udevice *dev, int id, int *val);
+
+/**
+ * board_get_str() - Read a specific string data value that describes the
+ * hardware setup.
+ *
+ * @dev: The board instance to gather the data.
+ * @id: A unique identifier for the string value to be read.
+ * @size: The size of the buffer to receive the string data.
+ * @val: Pointer to a buffer that receives the value read.
+ * @return 0 if OK, -ve on error.
+ */
+int board_get_str(struct udevice *dev, int id, size_t size, char *val);
+
+int get_board(struct udevice **devp);
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index d28fb3e23f..97327194b4 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -30,6 +30,7 @@ enum uclass_id {
UCLASS_ADC, /* Analog-to-digital converter */
UCLASS_AHCI, /* SATA disk controller */
UCLASS_BLK, /* Block device */
+ UCLASS_BOARD, /* Device information from hardware */
UCLASS_CLK, /* Clock source, e.g. used by peripherals */
UCLASS_CPU, /* CPU, typically part of an SoC */
UCLASS_CROS_EC, /* Chrome OS EC */
--
2.16.1
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