[U-Boot] [PATCH v2 1/2] bootcount: add uclass for bootcount
Philipp Tomsich
philipp.tomsich at theobroma-systems.com
Tue Nov 27 22:00:18 UTC 2018
The original bootcount methods do not provide an interface to DM and
rely on a static configuration for I2C devices (e.g. bus, chip-addr,
etc. are configured through defines statically). On a modern system
that exposes multiple devices in a DTS-configurable way, this is less
than optimal and a interface to DM-based devices will be desirable.
This adds a simple driver that is DM-aware and configurable via DTS.
If ambiguous (i.e. multiple bootcount-devices are present) the
/chosen/u-boot,bootcount-device property can be used to select one
bootcount device.
Initially, this provides support for the following DM devices:
* RTC devices
Signed-off-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>
Tested-by: Klaus Goger <klaus.goger at theobroma-systems.com>
---
Changes in v2:
- changed to provide a UCLASS-based implementation, as requested by
SJG in his earlier review
- split off the RV3029 driver into a separate series
doc/device-tree-bindings/chosen.txt | 30 ++++++++++++
drivers/bootcount/Kconfig | 8 ++++
drivers/bootcount/Makefile | 2 +
drivers/bootcount/bootcount-uclass.c | 93 ++++++++++++++++++++++++++++++++++++
include/bootcount.h | 48 +++++++++++++++++++
include/dm/uclass-id.h | 1 +
6 files changed, 182 insertions(+)
create mode 100644 drivers/bootcount/bootcount-uclass.c
diff --git a/doc/device-tree-bindings/chosen.txt b/doc/device-tree-bindings/chosen.txt
index 86c533a..395c950 100644
--- a/doc/device-tree-bindings/chosen.txt
+++ b/doc/device-tree-bindings/chosen.txt
@@ -42,6 +42,36 @@ Example
};
};
+u-boot,bootcount-device property
+--------------------------------
+
+In a DM-based system, the bootcount may be stored in a device known to
+the DM framework (e.g. in a battery-backed SRAM area within a RTC
+device) managed by a device conforming to UCLASS_BOOTCOUNT. If
+multiple such devices are present in a system concurrently, then the
+u-boot,bootcount-device property can select the preferred target.
+
+Example
+-------
+/ {
+ chosen {
+ u-boot,bootcount-device = &bootcount-rv3029;
+ };
+
+ bootcount-rv3029: bootcount at 0 {
+ compatible = "u-boot,bootcount-rtc";
+ rtc = &rv3029;
+ offset = <0x38>;
+ };
+
+ i2c2 {
+ rv3029: rtc at 56 {
+ compatible = "mc,rv3029";
+ reg = <0x56>;
+ };
+ };
+};
+
u-boot,spl-boot-order property
------------------------------
diff --git a/drivers/bootcount/Kconfig b/drivers/bootcount/Kconfig
index 6703363..46571eb 100644
--- a/drivers/bootcount/Kconfig
+++ b/drivers/bootcount/Kconfig
@@ -70,6 +70,14 @@ config BOOTCOUNT_AT91
bool "Boot counter for Atmel AT91SAM9XE"
depends on AT91SAM9XE
+config DM_BOOTCOUNT
+ bool "Boot counter in a device-model device"
+ help
+ Enables reading/writing the bootcount in a device-model based
+ backing store. If an entry in /chosen/u-boot,bootcount-device
+ exists, this will be the preferred bootcount device; otherwise
+ the first available bootcount device will be used.
+
endchoice
config BOOTCOUNT_BOOTLIMIT
diff --git a/drivers/bootcount/Makefile b/drivers/bootcount/Makefile
index 68bc006..81980b3 100644
--- a/drivers/bootcount/Makefile
+++ b/drivers/bootcount/Makefile
@@ -7,3 +7,5 @@ obj-$(CONFIG_BOOTCOUNT_RAM) += bootcount_ram.o
obj-$(CONFIG_BOOTCOUNT_ENV) += bootcount_env.o
obj-$(CONFIG_BOOTCOUNT_I2C) += bootcount_i2c.o
obj-$(CONFIG_BOOTCOUNT_EXT) += bootcount_ext.o
+
+obj-$(CONFIG_DM_BOOTCOUNT) += bootcount-uclass.o
diff --git a/drivers/bootcount/bootcount-uclass.c b/drivers/bootcount/bootcount-uclass.c
new file mode 100644
index 0000000..0689db7
--- /dev/null
+++ b/drivers/bootcount/bootcount-uclass.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2018 Theobroma Systems Design und Consulting GmbH
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <bootcount.h>
+
+int dm_bootcount_get(struct udevice *dev, u32 *bootcount)
+{
+ struct bootcount_ops *ops = bootcount_get_ops(dev);
+
+ assert(ops);
+ if (!ops->get)
+ return -ENOSYS;
+ return ops->get(dev, bootcount);
+}
+
+int dm_bootcount_set(struct udevice *dev, const u32 bootcount)
+{
+ struct bootcount_ops *ops = bootcount_get_ops(dev);
+
+ assert(ops);
+ if (!ops->set)
+ return -ENOSYS;
+ return ops->set(dev, bootcount);
+}
+
+/* Now implement the generic default functions */
+void bootcount_store(ulong val)
+{
+ struct udevice *dev = NULL;
+ ofnode node;
+ const char *propname = "u-boot,bootcount-device";
+ int ret = -ENODEV;
+
+ /*
+ * If there's a preferred bootcount device selected by the user (by
+ * setting '/chosen/u-boot,bootcount-device' in the DTS), try to use
+ * it if available.
+ */
+ node = ofnode_get_chosen_node(propname);
+ if (ofnode_valid(node))
+ ret = uclass_get_device_by_ofnode(UCLASS_BOOTCOUNT, node, &dev);
+
+ /* If there was no user-selected device, use the first available one */
+ if (ret)
+ ret = uclass_get_device(UCLASS_BOOTCOUNT, 0, &dev);
+
+ if (dev)
+ ret = dm_bootcount_set(dev, val);
+
+ if (ret)
+ pr_debug("%s: failed to store 0x%lx\n", __func__, val);
+}
+
+ulong bootcount_load(void)
+{
+ struct udevice *dev = NULL;
+ ofnode node;
+ const char *propname = "u-boot,bootcount-device";
+ int ret = -ENODEV;
+ u32 val;
+
+ /*
+ * If there's a preferred bootcount device selected by the user (by
+ * setting '/chosen/u-boot,bootcount-device' in the DTS), try to use
+ * it if available.
+ */
+ node = ofnode_get_chosen_node(propname);
+ if (ofnode_valid(node))
+ ret = uclass_get_device_by_ofnode(UCLASS_BOOTCOUNT, node, &dev);
+
+ /* If there was no user-selected device, use the first available one */
+ if (ret)
+ ret = uclass_get_device(UCLASS_BOOTCOUNT, 0, &dev);
+
+ if (dev)
+ ret = dm_bootcount_get(dev, &val);
+
+ if (ret)
+ pr_debug("%s: failed to load bootcount\n", __func__);
+
+ /* Return the 0, if the call to dm_bootcount_get failed */
+ return ret ? 0 : val;
+}
+
+UCLASS_DRIVER(bootcount) = {
+ .name = "bootcount",
+ .id = UCLASS_BOOTCOUNT,
+};
diff --git a/include/bootcount.h b/include/bootcount.h
index 671adcc..daee843 100644
--- a/include/bootcount.h
+++ b/include/bootcount.h
@@ -10,6 +10,54 @@
#include <asm/io.h>
#include <asm/byteorder.h>
+#ifdef CONFIG_DM_BOOTCOUNT
+
+struct bootcount_ops {
+ /**
+ * get() - get the current bootcount value
+ *
+ * Returns the current counter value of the bootcount backing
+ * store.
+ *
+ * @dev: Device to read from
+ * @bootcount: Address to put the current bootcount value
+ */
+ int (*get)(struct udevice *dev, u32 *bootcount);
+
+ /**
+ * set() - set a bootcount value (e.g. to reset or increment)
+ *
+ * Sets the value in the bootcount backing store.
+ *
+ * @dev: Device to read from
+ * @bootcount: New bootcount value to store
+ */
+ int (*set)(struct udevice *dev, const u32 bootcount);
+};
+
+/* Access the operations for a bootcount device */
+#define bootcount_get_ops(dev) ((struct bootcount_ops *)(dev)->driver->ops)
+
+/**
+ * dm_bootcount_get() - Read the current value from a bootcount storage
+ *
+ * @dev: Device to read from
+ * @bootcount: Place to put the current bootcount
+ * @return 0 if OK, -ve on error
+ */
+int dm_bootcount_get(struct udevice *dev, u32 *bootcount);
+
+/**
+ * dm_bootcount_set() - Write a value to a bootcount storage
+ *
+ * @dev: Device to read from
+ * @bootcount: Value to be written to the backing storage
+ * @return 0 if OK, -ve on error
+ */
+int dm_bootcount_set(struct udevice *dev, u32 bootcount);
+
+#endif
+
#if defined(CONFIG_SPL_BOOTCOUNT_LIMIT) || defined(CONFIG_BOOTCOUNT_LIMIT)
#if !defined(CONFIG_SYS_BOOTCOUNT_LE) && !defined(CONFIG_SYS_BOOTCOUNT_BE)
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index aad5d26..0e41f8a 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -32,6 +32,7 @@ enum uclass_id {
UCLASS_AXI, /* AXI bus */
UCLASS_BLK, /* Block device */
UCLASS_BOARD, /* Device information from hardware */
+ UCLASS_BOOTCOUNT, /* Bootcount backing store */
UCLASS_CLK, /* Clock source, e.g. used by peripherals */
UCLASS_CPU, /* CPU, typically part of an SoC */
UCLASS_CROS_EC, /* Chrome OS EC */
--
2.1.4
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