[PATCH 2/4] bootcount: add simple register support

[Jean-Christophe PLAGNIOL-VILLARD]

use a register to store the boot count
if 2 ressources: one for magic, one for value
otherwise 16 upper bit for magic 16 lower for value

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
---
 drivers/misc/bootcount/Kconfig    |   7 +++
 drivers/misc/bootcount/Makefile   |   1 +
 drivers/misc/bootcount/register.c | 107 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 115 insertions(+)
 create mode 100644 drivers/misc/bootcount/register.c

diff --git a/drivers/misc/bootcount/Kconfig b/drivers/misc/bootcount/Kconfig
index 77a1140..c028cf9 100644
--- a/drivers/misc/bootcount/Kconfig
+++ b/drivers/misc/bootcount/Kconfig
@@ -9,4 +9,11 @@ menuconfig BOOTCOUNT
 
 if BOOTCOUNT
 
+config BOOTCOUNT_REGISTER
+	tristate "Register"
+	help
+	  use a register to store the boot count
+	  if 2 ressources: one for magic, one for value
+	  otherwise 16 upper bit for magic 16 lower for value
+
 endif # BOOTCOUNT
diff --git a/drivers/misc/bootcount/Makefile b/drivers/misc/bootcount/Makefile
index 3c02ba1..cb6cb27 100644
--- a/drivers/misc/bootcount/Makefile
+++ b/drivers/misc/bootcount/Makefile
@@ -1 +1,2 @@
 obj-y		+= core.o
+obj-$(CONFIG_BOOTCOUNT_REGISTER) += register.o
diff --git a/drivers/misc/bootcount/register.c b/drivers/misc/bootcount/register.c
new file mode 100644
index 0000000..fc57f70
--- /dev/null
+++ b/drivers/misc/bootcount/register.c
@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2013 Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
+ *
+ * GPLv2 Only
+ */
+
+#include <common.h>
+#include <driver.h>
+#include <init.h>
+#include <io.h>
+#include <errno.h>
+#include <bootcount.h>
+
+#define BOOTCOUNT_MAGIC	0xb001c041
+
+struct bootcount_register {
+	struct device_d *dev;
+	void __iomem *base;
+	void __iomem *magic;
+	void (*set)(struct bootcount_register *br);
+
+	struct bootcount_driver drv;
+};
+
+static void bootcount_register_set_one(struct bootcount_register *br)
+{
+	u32 val;
+
+	val = BOOTCOUNT_MAGIC | (br->drv.count & 0xffff);
+
+	writel(val, br->base);
+}
+
+static void bootcount_register_set_two(struct bootcount_register *br)
+{
+	writel(BOOTCOUNT_MAGIC, br->magic);
+	writel(br->drv.count, br->base);
+}
+
+static void bootcount_register_parse_one(struct bootcount_register *br)
+{
+	u32 val;
+
+	val = readl(br->base);
+
+	if ((val & 0xffff0000) != (BOOTCOUNT_MAGIC& 0xffff0000))
+		return;
+
+	br->drv.count = val & 0xffff;
+}
+
+static void bootcount_register_parse_two(struct bootcount_register *br)
+{
+	u32 val;
+
+	val = readl(br->magic);
+
+	if (val != BOOTCOUNT_MAGIC)
+		return;
+
+	br->drv.count = readl(br->base);
+}
+
+static void bootcount_register_drv_set(struct bootcount_driver *d)
+{
+	struct bootcount_register *br = d->priv;
+
+	br->set(br);
+}
+
+static int bootcount_register_probe(struct device_d *dev)
+{
+	struct bootcount_register *br;
+	int ret;
+
+	br = xzalloc(sizeof(*br));
+	br->base = dev_request_mem_region(dev, 0);
+	br->magic = dev_request_mem_region(dev, 1);
+	br->dev = dev;
+
+	br->drv.priv = br;
+	br->drv.set = bootcount_register_drv_set;
+	br->drv.parent = dev;
+	if (!br->magic) {
+		bootcount_register_parse_one(br);
+		br->set = bootcount_register_set_one;
+	} else {
+		bootcount_register_parse_two(br);
+		br->set = bootcount_register_set_two;
+	}
+	ret = register_bootcount(&br->drv);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static struct driver_d bootcount_register_driver = {
+	.name = "bootcount_register",
+	.probe = bootcount_register_probe,
+};
+
+static int bootcount_register_init(void)
+{
+	return platform_driver_register(&bootcount_register_driver);
+}
+postcore_initcall(bootcount_register_init);
-- 
1.8.4.rc1