Hi Philipp, > 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: > the /chosen/u-boot,bootcount-device property is used to detect the DM > device storing the bootcount and deviceclass-specific commands are > used to read/write the bootcount. > > Initially, this provides support for the following DM devices: > * RTC devices implementing the read8/write8 ops > > Signed-off-by: Philipp Tomsich <philipp.toms...@theobroma-systems.com> > Tested-by: Klaus Goger <klaus.go...@theobroma-systems.com> > --- > > doc/device-tree-bindings/chosen.txt | 27 +++++++++++ > drivers/bootcount/Kconfig | 12 +++++ > drivers/bootcount/Makefile | 1 + > drivers/bootcount/bootcount_dm.c | 93 > +++++++++++++++++++++++++++++++++++++ 4 files changed, 133 > insertions(+) create mode 100644 drivers/bootcount/bootcount_dm.c > > diff --git a/doc/device-tree-bindings/chosen.txt > b/doc/device-tree-bindings/chosen.txt index da7b4e6..734fd15 100644 > --- a/doc/device-tree-bindings/chosen.txt > +++ b/doc/device-tree-bindings/chosen.txt > @@ -42,6 +42,33 @@ 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). To identify the device to be used for the bootcount, the > +u-boot,bootcount-device property needs to point to the target device. > + > +Further configuration in the target device's node may be required > +(e.g. an offset into an I2C RTC's address space), depending on the > +UCLASS of the target device. > + > +Example > +------- > +/ { > + chosen { > + u-boot,bootcount-device = &rv3029; > + }; > + > + i2c2 { > + rv3029: rtc@56 { > + compatible = "mc,rv3029"; > + reg = <0x56>; > + u-boot,bootcount-offset = <0x38>; > + }; > + }; > +}; > + > u-boot,spl-boot-order property > ------------------------------ > > diff --git a/drivers/bootcount/Kconfig b/drivers/bootcount/Kconfig > index d335ed1..cdde7b5 100644 > --- a/drivers/bootcount/Kconfig > +++ b/drivers/bootcount/Kconfig > @@ -70,6 +70,18 @@ config BOOTCOUNT_AT91 > bool "Boot counter for Atmel AT91SAM9XE" > depends on AT91SAM9XE > > +config BOOTCOUNT_DM > + bool "Boot counter in a device-model device" > + help > + Enables reading/writing the bootcount in a device-model > + device referenced from the /chosen node. The type of the > + device is detected from DM and any additional configuration > + information (e.g. the offset into a RTC device that > supports > + read32/write32) is read from the device's node. > + > + At this time the following DM device classes are supported: > + * RTC (using read32/write32) > + > endchoice > > config BOOTCOUNT_ALEN > diff --git a/drivers/bootcount/Makefile b/drivers/bootcount/Makefile > index 68bc006..e8ed729 100644 > --- a/drivers/bootcount/Makefile > +++ b/drivers/bootcount/Makefile > @@ -7,3 +7,4 @@ 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_DM) += bootcount_dm.o > diff --git a/drivers/bootcount/bootcount_dm.c > b/drivers/bootcount/bootcount_dm.c new file mode 100644 > index 0000000..99bdb88 > --- /dev/null > +++ b/drivers/bootcount/bootcount_dm.c > @@ -0,0 +1,93 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * (C) Copyright 2018 Theobroma Systems Design und Consulting GmbH > + */ > + > +#include <common.h> > +#include <bootcount.h> > +#include <dm.h> > +#include <rtc.h> > + > +const u8 bootcount_magic = 0xbc; > + > +static void bootcount_store_rtc(struct udevice *dev, ulong a) > +{ > +#if CONFIG_IS_ENABLED(DM_RTC) > + u32 offset; > + const char *offset_propname = "u-boot,bootcount-offset"; > + const u16 val = bootcount_magic << 8 | (a & 0xff); > + > + if (dev_read_u32(dev, offset_propname, &offset) < 0) { > + debug("%s: requires %s\n", __func__, > offset_propname); > + return; > + } > + > + if (rtc_write16(dev, offset, val) < 0) { > + debug("%s: rtc_write16 failed\n", __func__); > + return; > + } > +#endif > +} > + > +static u32 bootcount_load_rtc(struct udevice *dev) > +{ > +#if CONFIG_IS_ENABLED(DM_RTC) > + u32 offset; > + const char *offset_propname = "u-boot,bootcount-offset"; > + u16 val; > + > + if (dev_read_u32(dev, offset_propname, &offset) < 0) { > + debug("%s: requires %s\n", __func__, > offset_propname); > + goto fail; > + } > + > + if (rtc_read16(dev, offset, &val) < 0) { > + debug("%s: rtc_write16 failed\n", __func__); > + goto fail; > + } > + > + if (val >> 8 == bootcount_magic) > + return val & 0xff; > + > + debug("%s: bootcount magic does not match on %04x\n", > __func__, val); > + fail: > +#endif > + return 0; > +} > + > +/* Now implement the generic default functions */ > +void bootcount_store(ulong a) > +{ > + struct udevice *dev; > + ofnode node; > + const char *propname = "u-boot,bootcount-device"; > + > + node = ofnode_get_chosen_node(propname); > + if (!ofnode_valid(node)) { > + debug("%s: no '%s'\n", __func__, propname); > + return; > + } > + > + /* RTC devices */ > + if (!uclass_get_device_by_ofnode(UCLASS_RTC, node, &dev)) > + return bootcount_store_rtc(dev, a); > +} > + > +ulong bootcount_load(void) > +{ > + struct udevice *dev; > + ofnode node; > + const char *propname = "u-boot,bootcount-device"; > + > + node = ofnode_get_chosen_node(propname); > + if (!ofnode_valid(node)) { > + debug("%s: no '%s'\n", __func__, propname); > + return 0; > + } > + > + /* RTC devices */ > + if (!uclass_get_device_by_ofnode(UCLASS_RTC, node, &dev)) > + return bootcount_load_rtc(dev); > + > + return 0; > +}
Thanks for your patch. However, if I may ask - would it be possible to add support for EEPROM based bootcount in an easy way? I mean - do you think that it would be feasible to have bootcount-uclass, which would support generic load/store functions with DM drivers for RTC, EEPROM or even simple write to SFR registers (as it is just an offset in the end)? Best regards, Lukasz Majewski -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de
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