[PATCH v2] bootcounter: add DM support for memory based bootcounter

[Heiko Schocher]

add DM/DTS support for the memory based bootcounter
in drivers/bootcount/bootcount.c.

Let the old implementation in, so boards which have
not yet convert to DM/DTS do not break.

Signed-off-by: Heiko Schocher <hs at denx.de>
---
Travis build:
https://travis-ci.org/hsdenx/u-boot-test/builds/657150708

Changes in v2:
- add changes requested from Simon Glass
  - add comment to struct bootcount_mem_priv
  - change type of singleword from u8 to bool
  - use dev_read_addr() and dev_read_bool()
  - use "u-boot,bootcount" for compatible
    string instead "uboot,bootcount"

 doc/device-tree-bindings/misc/bootcounter.txt | 21 +++++
 drivers/bootcount/Kconfig                     |  7 ++
 drivers/bootcount/Makefile                    |  1 +
 drivers/bootcount/bootcount.c                 | 92 +++++++++++++++++++
 4 files changed, 121 insertions(+)
 create mode 100644 doc/device-tree-bindings/misc/bootcounter.txt

diff --git a/doc/device-tree-bindings/misc/bootcounter.txt b/doc/device-tree-bindings/misc/bootcounter.txt
new file mode 100644
index 0000000000..d32fbc37b2
--- /dev/null
+++ b/doc/device-tree-bindings/misc/bootcounter.txt
@@ -0,0 +1,21 @@
+U-Boot bootcounter Devicetree Binding
+=====================================
+
+The device tree node describes the U-Boot bootcounter
+memory based device binding.
+
+Required properties :
+
+- compatible : "u-boot,bootcount";
+- single-word : set this, if you have only one word space
+    for storing the bootcounter.
+
+Example
+-------
+
+MPC83xx based board:
+
+bootcount at 0x13ff8 {
+	compatible = "u-boot,bootcount";
+	reg = <0x13ff8 0x08>;
+};
diff --git a/drivers/bootcount/Kconfig b/drivers/bootcount/Kconfig
index 0e506c9ea2..0356f8ba18 100644
--- a/drivers/bootcount/Kconfig
+++ b/drivers/bootcount/Kconfig
@@ -106,6 +106,13 @@ config DM_BOOTCOUNT_I2C_EEPROM
 	  pointing to the underlying i2c eeprom device) and an optional 'offset'
 	  property are supported.
 
+config BOOTCOUNT_MEM
+	bool "Support memory based bootcounter"
+	help
+	  Enabling Memory based bootcount, typically in a SoC register which
+	  is not cleared on softreset.
+	  compatible = "u-boot,bootcount";
+
 endmenu
 
 endif
diff --git a/drivers/bootcount/Makefile b/drivers/bootcount/Makefile
index 73ccfb5a08..059d40d16b 100644
--- a/drivers/bootcount/Makefile
+++ b/drivers/bootcount/Makefile
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0+
 
 obj-$(CONFIG_BOOTCOUNT_GENERIC)	+= bootcount.o
+obj-$(CONFIG_BOOTCOUNT_MEM)	+= bootcount.o
 obj-$(CONFIG_BOOTCOUNT_AT91)	+= bootcount_at91.o
 obj-$(CONFIG_BOOTCOUNT_AM33XX)	+= bootcount_davinci.o
 obj-$(CONFIG_BOOTCOUNT_RAM)	+= bootcount_ram.o
diff --git a/drivers/bootcount/bootcount.c b/drivers/bootcount/bootcount.c
index 7a6d03dcca..655dfaf59c 100644
--- a/drivers/bootcount/bootcount.c
+++ b/drivers/bootcount/bootcount.c
@@ -8,6 +8,7 @@
 #include <cpu_func.h>
 #include <linux/compiler.h>
 
+#if !defined(CONFIG_DM_BOOTCOUNT)
 /* Now implement the generic default functions */
 __weak void bootcount_store(ulong a)
 {
@@ -49,3 +50,94 @@ __weak ulong bootcount_load(void)
 		return raw_bootcount_load(reg);
 #endif /* defined(CONFIG_SYS_BOOTCOUNT_SINGLEWORD) */
 }
+#else
+#include <dm.h>
+
+/*
+ * struct bootcount_mem_priv - private bootcount mem driver data
+ *
+ * @base: base address used for bootcounter
+ * @singleword: if true use only one 32 bit word for bootcounter
+ */
+struct bootcount_mem_priv {
+	phys_addr_t base;
+	bool singleword;
+};
+
+static int bootcount_mem_get(struct udevice *dev, u32 *a)
+{
+	struct bootcount_mem_priv *priv = dev_get_priv(dev);
+	void *reg = (void *)priv->base;
+	u32 magic = CONFIG_SYS_BOOTCOUNT_MAGIC;
+
+	if (priv->singleword) {
+		u32 tmp = raw_bootcount_load(reg);
+
+		if ((tmp & 0xffff0000) != (magic & 0xffff0000))
+			return -ENODEV;
+
+		*a = (tmp & 0x0000ffff);
+	} else {
+		if (raw_bootcount_load(reg + 4) != magic)
+			return -ENODEV;
+
+		*a = raw_bootcount_load(reg);
+	}
+
+	return 0;
+};
+
+static int bootcount_mem_set(struct udevice *dev, const u32 a)
+{
+	struct bootcount_mem_priv *priv = dev_get_priv(dev);
+	void *reg = (void *)priv->base;
+	u32 magic = CONFIG_SYS_BOOTCOUNT_MAGIC;
+	uintptr_t flush_start = rounddown(priv->base,
+					  CONFIG_SYS_CACHELINE_SIZE);
+	uintptr_t flush_end;
+
+	if (priv->singleword) {
+		raw_bootcount_store(reg, (magic & 0xffff0000) | a);
+		flush_end = roundup(priv->base + 4,
+				    CONFIG_SYS_CACHELINE_SIZE);
+	} else {
+		raw_bootcount_store(reg, a);
+		raw_bootcount_store(reg + 4, magic);
+		flush_end = roundup(priv->base + 8,
+				    CONFIG_SYS_CACHELINE_SIZE);
+	}
+	flush_dcache_range(flush_start, flush_end);
+
+	return 0;
+};
+
+static const struct bootcount_ops bootcount_mem_ops = {
+	.get = bootcount_mem_get,
+	.set = bootcount_mem_set,
+};
+
+static int bootcount_mem_probe(struct udevice *dev)
+{
+	struct bootcount_mem_priv *priv = dev_get_priv(dev);
+
+	priv->base = (phys_addr_t)dev_read_addr(dev);
+	if (dev_read_bool(dev, "single-word"))
+		priv->singleword = true;
+
+	return 0;
+}
+
+static const struct udevice_id bootcount_mem_ids[] = {
+	{ .compatible = "u-boot,bootcount" },
+	{ }
+};
+
+U_BOOT_DRIVER(bootcount_mem) = {
+	.name	= "bootcount-mem",
+	.id	= UCLASS_BOOTCOUNT,
+	.priv_auto_alloc_size = sizeof(struct bootcount_mem_priv),
+	.probe	= bootcount_mem_probe,
+	.of_match = bootcount_mem_ids,
+	.ops	= &bootcount_mem_ops,
+};
+#endif
-- 
2.24.1