[PATCH 1/1] bootcount: add a new driver with syscon as backend
Nandor Han
nandor.han at vaisala.com
Wed Apr 21 15:02:14 CEST 2021
The driver will use a syscon regmap as backend and supports both
16 and 32 size value. The value will be stored in the CPU's endianness.
Signed-off-by: Nandor Han <nandor.han at vaisala.com>
---
Notes:
Description
-----------
Add a new driver for bootcount feature that supports `syscon` device as
backend.
Testing
-------
UnitTests:
1. Verify that unit-tests run successfully: PASS
```
./test/py/test.py --bd sandbox --build -k ut_dm_bootcount -v
test/py/tests/test_ut.py::test_ut[ut_dm_bootcount_rtc] PASSED [ 33%]
test/py/tests/test_ut.py::test_ut[ut_dm_bootcount_syscon_four_bytes] PASSED [ 66%]
test/py/tests/test_ut.py::test_ut[ut_dm_bootcount_syscon_two_bytes] PASSED [100%]
```
Using hardware:
Board: i.MX6sx based dev board
U-Boot version: 2020.01
1. Use `bootcount` command to verity that value is updated
correctly: PASS
arch/sandbox/dts/test.dts | 14 ++
configs/sandbox_defconfig | 1 +
doc/device-tree-bindings/bootcount-syscon.txt | 25 +++
drivers/bootcount/Kconfig | 12 ++
drivers/bootcount/Makefile | 1 +
drivers/bootcount/bootcount_syscon.c | 159 ++++++++++++++++++
test/dm/bootcount.c | 48 +++++-
7 files changed, 257 insertions(+), 3 deletions(-)
create mode 100644 doc/device-tree-bindings/bootcount-syscon.txt
create mode 100644 drivers/bootcount/bootcount_syscon.c
diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index 48240aa26f..dadea0f0de 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -701,6 +701,20 @@
i2c-eeprom = <&bootcount_i2c>;
};
+ bootcount_4 at 0 {
+ compatible = "u-boot,bootcount-syscon";
+ syscon = <&syscon0>;
+ reg = <0x0 0x04>, <0x0 0x04>;
+ reg-names = "syscon_reg", "offset";
+ };
+
+ bootcount_2 at 0 {
+ compatible = "u-boot,bootcount-syscon";
+ syscon = <&syscon0>;
+ reg = <0x0 0x04>, <0x0 0x02> ;
+ reg-names = "syscon_reg", "offset";
+ };
+
adc: adc at 0 {
compatible = "sandbox,adc";
#io-channel-cells = <1>;
diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index d3de9c3155..465c184ade 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -123,6 +123,7 @@ CONFIG_AXI=y
CONFIG_AXI_SANDBOX=y
CONFIG_BOOTCOUNT_LIMIT=y
CONFIG_DM_BOOTCOUNT=y
+CONFIG_DM_BOOTCOUNT_SYSCON=y
CONFIG_DM_BOOTCOUNT_RTC=y
CONFIG_DM_BOOTCOUNT_I2C_EEPROM=y
CONFIG_BUTTON=y
diff --git a/doc/device-tree-bindings/bootcount-syscon.txt b/doc/device-tree-bindings/bootcount-syscon.txt
new file mode 100644
index 0000000000..f2482b3c6f
--- /dev/null
+++ b/doc/device-tree-bindings/bootcount-syscon.txt
@@ -0,0 +1,25 @@
+Bootcount Configuration
+This is the implementation of the feature as described in
+https://www.denx.de/wiki/DULG/UBootBootCountLimit.
+
+Required Properties:
+- compatible: must be "u-boot,bootcount-syscon".
+- syscon: reference to the syscon device used.
+- reg: contains address and size of the register and the location and size of the bootcount value.
+ The driver supports a 4 bytes register length and 2 and 4 bytes bootcount value length.
+- reg-names: must be "syscon_reg", "offset";
+
+Example:
+ ...
+ syscon0: syscon at 0 {
+ compatible = "sandbox,syscon0";
+ reg = <0x10 16>;
+ };
+ ...
+ bootcount at 0 {
+ compatible = "u-boot,bootcount-syscon";
+ syscon = <&syscon0>;
+ reg = <0x0 0x04>, <0x0 0x04>;
+ reg-names = "syscon_reg", "offset";
+ };
+
diff --git a/drivers/bootcount/Kconfig b/drivers/bootcount/Kconfig
index b5ccea0d9c..41a5c919d5 100644
--- a/drivers/bootcount/Kconfig
+++ b/drivers/bootcount/Kconfig
@@ -125,6 +125,18 @@ config BOOTCOUNT_MEM
is not cleared on softreset.
compatible = "u-boot,bootcount";
+config DM_BOOTCOUNT_SYSCON
+ bool "Support SYSCON devices as a backing store for bootcount"
+ select REGMAP
+ select SYSCON
+ help
+ Enable reading/writing the bootcount value in a DM SYSCON device.
+ The driver supports a fixed 32 bits size register using the native
+ endianness. However, this can be controlled from the SYSCON DT node
+ configuration.
+
+ Accessing the backend is done using the regmap interface.
+
endmenu
endif
diff --git a/drivers/bootcount/Makefile b/drivers/bootcount/Makefile
index 51d860b00e..10fadf4fe9 100644
--- a/drivers/bootcount/Makefile
+++ b/drivers/bootcount/Makefile
@@ -13,3 +13,4 @@ obj-$(CONFIG_DM_BOOTCOUNT) += bootcount-uclass.o
obj-$(CONFIG_DM_BOOTCOUNT_RTC) += rtc.o
obj-$(CONFIG_DM_BOOTCOUNT_I2C_EEPROM) += i2c-eeprom.o
obj-$(CONFIG_DM_BOOTCOUNT_SPI_FLASH) += spi-flash.o
+obj-$(CONFIG_DM_BOOTCOUNT_SYSCON) += bootcount_syscon.o
diff --git a/drivers/bootcount/bootcount_syscon.c b/drivers/bootcount/bootcount_syscon.c
new file mode 100644
index 0000000000..413fd5bb9d
--- /dev/null
+++ b/drivers/bootcount/bootcount_syscon.c
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) Vaisala Oyj. All rights reserved.
+ */
+
+#include <common.h>
+#include <bootcount.h>
+#include <dm.h>
+#include <dm/device_compat.h>
+#include <linux/ioport.h>
+#include <regmap.h>
+#include <syscon.h>
+
+#define BYTES_TO_BITS(bytes) ((bytes) << 3)
+#define GEN_REG_MASK(val_size, val_addr) \
+ (GENMASK(BYTES_TO_BITS(val_size) - 1, 0) \
+ << (!!((val_addr) == 0x02) * BYTES_TO_BITS(2)))
+#define GET_DEFAULT_VALUE(val_size) \
+ (CONFIG_SYS_BOOTCOUNT_MAGIC >> \
+ (BYTES_TO_BITS((sizeof(u32) - (val_size)))))
+
+/**
+ * struct bootcount_syscon_priv - driver's private data
+ *
+ * @regmap: syscon regmap
+ * @reg_addr: register address used to store the bootcount value
+ * @size: size of the bootcount value (2 or 4 bytes)
+ * @magic: magic used to validate/save the bootcount value
+ * @magic_mask: magic value bitmask
+ * @reg_mask: mask used to identify the location of the bootcount value
+ * in the register when 2 bytes length is used
+ * @shift: value used to extract the botcount value from the register
+ */
+struct bootcount_syscon_priv {
+ struct regmap *regmap;
+ fdt_addr_t reg_addr;
+ fdt_size_t size;
+ u32 magic;
+ u32 magic_mask;
+ u32 reg_mask;
+ int shift;
+};
+
+static int bootcount_syscon_set(struct udevice *dev, const u32 val)
+{
+ struct bootcount_syscon_priv *priv = dev_get_priv(dev);
+ u32 regval;
+
+ if ((val & priv->magic_mask) != 0)
+ return -EINVAL;
+
+ regval = (priv->magic & priv->magic_mask) | (val & ~priv->magic_mask);
+
+ if (priv->size == 2) {
+ regval &= 0xffff;
+ regval |= (regval & 0xffff) << BYTES_TO_BITS(priv->size);
+ }
+
+ debug("%s: Prepare to write reg value: 0x%08x with register mask: 0x%08x\n",
+ __func__, regval, priv->reg_mask);
+
+ return regmap_update_bits(priv->regmap, priv->reg_addr, priv->reg_mask,
+ regval);
+}
+
+static int bootcount_syscon_get(struct udevice *dev, u32 *val)
+{
+ struct bootcount_syscon_priv *priv = dev_get_priv(dev);
+ u32 regval;
+ int ret;
+
+ ret = regmap_read(priv->regmap, priv->reg_addr, ®val);
+ if (ret)
+ return ret;
+
+ regval &= priv->reg_mask;
+ regval >>= priv->shift;
+
+ if ((regval & priv->magic_mask) == (priv->magic & priv->magic_mask)) {
+ *val = regval & ~priv->magic_mask;
+ } else {
+ dev_err(dev, "%s: Invalid bootcount magic\n", __func__);
+ return -EINVAL;
+ }
+
+ debug("%s: Read bootcount value: 0x%08x from regval: 0x%08x\n",
+ __func__, *val, regval);
+ return 0;
+}
+
+static int bootcount_syscon_of_to_plat(struct udevice *dev)
+{
+ struct bootcount_syscon_priv *priv = dev_get_priv(dev);
+ fdt_addr_t bootcount_offset;
+ fdt_size_t reg_size;
+
+ priv->regmap = syscon_regmap_lookup_by_phandle(dev, "syscon");
+ if (IS_ERR(priv->regmap)) {
+ dev_err(dev, "%s: Unable to find regmap (%ld)\n", __func__,
+ PTR_ERR(priv->regmap));
+ return PTR_ERR(priv->regmap);
+ }
+
+ priv->reg_addr = dev_read_addr_size_name(dev, "syscon_reg", ®_size);
+ if (priv->reg_addr == FDT_ADDR_T_NONE) {
+ dev_err(dev, "%s: syscon_reg address not found\n", __func__);
+ return -EINVAL;
+ }
+ if (reg_size != 4) {
+ dev_err(dev, "%s: Unsupported register size: %d\n", __func__,
+ reg_size);
+ return -EINVAL;
+ }
+
+ bootcount_offset = dev_read_addr_size_name(dev, "offset", &priv->size);
+ if (bootcount_offset == FDT_ADDR_T_NONE) {
+ dev_err(dev, "%s: offset configuration not found\n", __func__);
+ return -EINVAL;
+ }
+ if (bootcount_offset + priv->size > reg_size) {
+ dev_err(dev,
+ "%s: Bootcount value doesn't fit in the reserved space\n",
+ __func__);
+ return -EINVAL;
+ }
+ if (priv->size != 2 && priv->size != 4) {
+ dev_err(dev,
+ "%s: Driver supports only 2 and 4 bytes bootcount size\n",
+ __func__);
+ return -EINVAL;
+ }
+
+ priv->magic = GET_DEFAULT_VALUE(priv->size);
+ priv->magic_mask = GENMASK(BYTES_TO_BITS(priv->size) - 1,
+ BYTES_TO_BITS(priv->size >> 1));
+ priv->shift = !!(bootcount_offset == 0x02) * BYTES_TO_BITS(priv->size);
+ priv->reg_mask = GEN_REG_MASK(priv->size, bootcount_offset);
+
+ return 0;
+}
+
+static const struct bootcount_ops bootcount_syscon_ops = {
+ .get = bootcount_syscon_get,
+ .set = bootcount_syscon_set,
+};
+
+static const struct udevice_id bootcount_syscon_ids[] = {
+ { .compatible = "u-boot,bootcount-syscon" },
+ {}
+};
+
+U_BOOT_DRIVER(bootcount_syscon) = {
+ .name = "bootcount-syscon",
+ .id = UCLASS_BOOTCOUNT,
+ .of_to_plat = bootcount_syscon_of_to_plat,
+ .priv_auto = sizeof(struct bootcount_syscon_priv),
+ .of_match = bootcount_syscon_ids,
+ .ops = &bootcount_syscon_ops,
+};
diff --git a/test/dm/bootcount.c b/test/dm/bootcount.c
index e0c47b5d7a..b77b472d1f 100644
--- a/test/dm/bootcount.c
+++ b/test/dm/bootcount.c
@@ -12,12 +12,13 @@
#include <test/test.h>
#include <test/ut.h>
-static int dm_test_bootcount(struct unit_test_state *uts)
+static int dm_test_bootcount_rtc(struct unit_test_state *uts)
{
struct udevice *dev;
u32 val;
- ut_assertok(uclass_get_device(UCLASS_BOOTCOUNT, 0, &dev));
+ ut_assertok(uclass_get_device_by_name(UCLASS_BOOTCOUNT, "bootcount at 0",
+ &dev));
ut_assertok(dm_bootcount_set(dev, 0));
ut_assertok(dm_bootcount_get(dev, &val));
ut_assert(val == 0);
@@ -36,5 +37,46 @@ static int dm_test_bootcount(struct unit_test_state *uts)
return 0;
}
-DM_TEST(dm_test_bootcount, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);
+DM_TEST(dm_test_bootcount_rtc, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);
+static int dm_test_bootcount_syscon_four_bytes(struct unit_test_state *uts)
+{
+ struct udevice *dev;
+ u32 val;
+
+ sandbox_set_enable_memio(true);
+ ut_assertok(uclass_get_device_by_name(UCLASS_BOOTCOUNT, "bootcount_4 at 0",
+ &dev));
+ ut_assertok(dm_bootcount_set(dev, 0xab));
+ ut_assertok(dm_bootcount_get(dev, &val));
+ ut_assert(val == 0xab);
+ ut_assertok(dm_bootcount_set(dev, 0));
+ ut_assertok(dm_bootcount_get(dev, &val));
+ ut_assert(val == 0);
+
+ return 0;
+}
+
+DM_TEST(dm_test_bootcount_syscon_four_bytes,
+ UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);
+
+static int dm_test_bootcount_syscon_two_bytes(struct unit_test_state *uts)
+{
+ struct udevice *dev;
+ u32 val;
+
+ sandbox_set_enable_memio(true);
+ ut_assertok(uclass_get_device_by_name(UCLASS_BOOTCOUNT, "bootcount_2 at 0",
+ &dev));
+ ut_assertok(dm_bootcount_set(dev, 0xab));
+ ut_assertok(dm_bootcount_get(dev, &val));
+ ut_assert(val == 0xab);
+ ut_assertok(dm_bootcount_set(dev, 0));
+ ut_assertok(dm_bootcount_get(dev, &val));
+ ut_assert(val == 0);
+
+ return 0;
+}
+
+DM_TEST(dm_test_bootcount_syscon_two_bytes,
+ UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);
--
2.26.3
More information about the U-Boot
mailing list