[PATCH v4 16/18] am335x, guardian: software update available status is stored in AM3352 RTC scracth register

[Gireesh.Hiremath]

From: Gireesh Hiremath <gireesh.hirem...@in.bosch.com>

RTC second scratch register[32-bit]:
  -zero byte hold boot count value
  -first byte hold update available state
  -second byte hold version
  -third byte hold magic number

Signed-off-by: Gireesh Hiremath <gireesh.hirem...@in.bosch.com>

Gbp-Pq: Topic apertis/guardian
Gbp-Pq: Name am335x-guardian-software-update-available-status-is-store.patch
---
 drivers/bootcount/Kconfig           | 34 +++++++++++++++--
 drivers/bootcount/Makefile          |  1 +
 drivers/bootcount/bootcount_nvmem.c | 57 +++++++++++++++++++++++++++++
 3 files changed, 89 insertions(+), 3 deletions(-)
 create mode 100644 drivers/bootcount/bootcount_nvmem.c

diff --git a/drivers/bootcount/Kconfig b/drivers/bootcount/Kconfig
index b5ccea0d9c..0de2b7bd78 100644
--- a/drivers/bootcount/Kconfig
+++ b/drivers/bootcount/Kconfig
@@ -42,6 +42,25 @@ config BOOTCOUNT_AM33XX
          This requires the RTC clocks, etc, to be enabled prior to use and
          not all boards with this IP block on it will have the RTC in use.
 
+config BOOTCOUNT_AM33XX_NVMEM
+       bool "Boot counter in AM33XX RTC IP block with upgrade_available flag"
+       depends on AM33XX
+        select SPL_AM33XX_ENABLE_RTC32K_OSC if AM33XX
+       help
+         Add support for maintaining bootcount,upgrade_available,
+         version and BOOTMAGIC in a AM33xx RTC IP block
+         scratch register2.
+
+         A bootcount driver for the RTC IP block found on many TI platforms.
+         This requires the RTC clocks, etc, to be enabled prior to use and
+         not all boards with this IP block on it will have the RTC in use.
+
+         If there is upgrade in software then "upgrade_available" is 1,
+         "bootcount" is incremented otherwise "upgrade_available" and
+         "bootcount" is  always 0. So the Userspace Application must set
+         the "upgrade_available" and "bootcount" variable to 0, if a boot
+         was successfully.
+
 config BOOTCOUNT_ENV
        bool "Boot counter in environment"
        help
@@ -177,16 +196,25 @@ config SYS_BOOTCOUNT_EXT_NAME
 
 config SYS_BOOTCOUNT_ADDR
        hex "RAM address used for reading and writing the boot counter"
-       default 0x44E3E000 if BOOTCOUNT_AM33XX
+       default 0x44E3E000 if BOOTCOUNT_AM33XX || BOOTCOUNT_AM33XX_NVMEM
        default 0xE0115FF8 if ARCH_LS1043A || ARCH_LS1021A
        depends on BOOTCOUNT_AM33XX || BOOTCOUNT_GENERIC || BOOTCOUNT_EXT || \
-                  BOOTCOUNT_I2C
+                  BOOTCOUNT_I2C || BOOTCOUNT_AM33XX_NVMEM
        help
          Set the address used for reading and writing the boot counter.
 
 config SYS_BOOTCOUNT_MAGIC
        hex "Magic value for the boot counter"
-       default 0xB001C041
+       default 0xB001C041 if BOOTCOUNT_GENERIC || BOOTCOUNT_EXT || \
+                             BOOTCOUNT_AM33XX || BOOTCOUNT_ENV || \
+                             BOOTCOUNT_RAM || BOOTCOUNT_I2C || \
+                             BOOTCOUNT_AT91 || DM_BOOTCOUNT
+       default 0xB0 if BOOTCOUNT_AM33XX_NVMEM
+       depends on BOOTCOUNT_GENERIC || BOOTCOUNT_EXT || \
+                  BOOTCOUNT_AM33XX || BOOTCOUNT_ENV || \
+                  BOOTCOUNT_RAM || BOOTCOUNT_I2C || \
+                  BOOTCOUNT_AT91 || DM_BOOTCOUNT || \
+                  BOOTCOUNT_AM33XX_NVMEM
        help
          Set the magic value used for the boot counter.
 
diff --git a/drivers/bootcount/Makefile b/drivers/bootcount/Makefile
index 51d860b00e..12658ffdce 100644
--- a/drivers/bootcount/Makefile
+++ b/drivers/bootcount/Makefile
@@ -8,6 +8,7 @@ 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_BOOTCOUNT_AM33XX_NVMEM)   += bootcount_nvmem.o
 
 obj-$(CONFIG_DM_BOOTCOUNT)      += bootcount-uclass.o
 obj-$(CONFIG_DM_BOOTCOUNT_RTC)  += rtc.o
diff --git a/drivers/bootcount/bootcount_nvmem.c 
b/drivers/bootcount/bootcount_nvmem.c
new file mode 100644
index 0000000000..5f266d5ec8
--- /dev/null
+++ b/drivers/bootcount/bootcount_nvmem.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2011
+ * Heiko Schocher, DENX Software Engineering, h...@denx.de.
+ * (C) Copyright 2018 Robert Bosch Power Tools GmbH.
+ *
+ * A bootcount driver for the RTC IP block found on many TI platforms.
+ * This requires the RTC clocks, etc, to be enabled prior to use and
+ * not all boards with this IP block on it will have the RTC in use.
+ */
+
+#include <bootcount.h>
+#include <asm/davinci_rtc.h>
+
+#define        BC_VERSION      2
+
+void bootcount_store(ulong bootcount)
+{
+       u8 upgrade_available = 0;
+       ulong val = 0;
+       struct davinci_rtc *reg =
+               (struct davinci_rtc *)CONFIG_SYS_BOOTCOUNT_ADDR;
+
+       val = raw_bootcount_load(&reg->scratch2);
+       upgrade_available = (val >> 8) & 0x000000ff;
+
+       /* Only update bootcount during upgrade process */
+       if (!upgrade_available)
+               bootcount = 0;
+
+       val = (bootcount & 0x000000ff) |
+             (upgrade_available << 8) |
+             (BC_VERSION << 16) |
+             (CONFIG_SYS_BOOTCOUNT_MAGIC << 24);
+
+       /*
+        * write RTC kick registers to enable write
+        * for RTC Scratch registers. Scratch register 2 is
+        * used for bootcount value.
+        */
+       writel(RTC_KICK0R_WE, &reg->kick0r);
+       writel(RTC_KICK1R_WE, &reg->kick1r);
+       raw_bootcount_store(&reg->scratch2, val);
+}
+
+ulong bootcount_load(void)
+{
+       unsigned long val = 0;
+       struct davinci_rtc *reg =
+               (struct davinci_rtc *)CONFIG_SYS_BOOTCOUNT_ADDR;
+
+       val = raw_bootcount_load(&reg->scratch2);
+       if ((val >> 24) != CONFIG_SYS_BOOTCOUNT_MAGIC)
+               return 0;
+       else
+               return val & 0x000000ff;
+}
-- 
2.20.1