The PMIC framework has been extended to support multiple instances of
the variety of devices responsible for power management.
This change allows supporting of e.g. fuel gauge, charger, MUIC (Micro USB
Interface Circuit).
Power related includes have been moved to ./include/power directory.
This is a first of a series of patches - in the future "pmic" will be
replaced with "power".
Two important issues:
1. The PMIC needs to be initialized just after malloc is configured
2. It uses list to hold information about available PMIC devices
Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Stefano Babic <sbabic@denx.de>
This driver uses the century bit of this RTC in the opposite way Linux does.
From Linux's rtc-pcf8563.c:
/*
* The meaning of MO_C bit varies by the chip type.
* From PCF8563 datasheet: this bit is toggled when the years
* register overflows from 99 to 00
* 0 indicates the century is 20xx
* 1 indicates the century is 19xx
* From RTC8564 datasheet: this bit indicates change of
* century. When the year digit data overflows from 99 to 00,
* this bit is set. By presetting it to 0 while still in the
* 20th century, it will be set in year 2000, ...
* There seems no reliable way to know how the system use this
* bit. So let's do it heuristically, assuming we are live in
* 1970...2069.
*/
As U-Boot's PCF8563 driver does not say it is supposed to support the RTC8564,
make this driver compatible with Linux's by giving the opposite meaning to the
century bit.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Cc: Wolfgang Denk <wd@denx.de>
The sys_proto.h functions (except the boot modes) are compatible with
i.MX233 and i.MX28 so we use 'mxs' prefix for its methods.
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Support for DS1388 is added by extending the DS1337 driver. DS1388 is
similar to DS1337. The time registers are offset by 1 (due to support
for hundreds of seconds), and there is no century bit.
The configuration and trickle charge registers are also different.
Tested on hardware with Freescale P2010 and DS1388.
Signed-off-by: Kenth Eriksson <kenth.eriksson@transmode.com>
Add support for the M41T82 RTC to the m41t62 driver. The only
difference that needs to be handled by this driver, is to
clear the HT (Halt Update) bit upon reset. This bit is not
used on the M41T62, so its save to clear this bit always.
The M41T82 support will be used by the X600 (SPEAr600)
board support.
Signed-off-by: Stefan Roese <sr@denx.de>
move struct davinci_rtc to arch/arm/include/asm/arch-davinci/hardware.h
and add RTC_KICK0R_WE, RTC_KICK1R_WE defines,
so they are global useable.
Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Sandeep Paulraj <s-paulraj@ti.com>
Fix:
s3c24x0_rtc.c: In function 'rtc_get':
s3c24x0_rtc.c:67:53: warning: variable 'a_armed' set but not used
s3c24x0_rtc.c:67:45: warning: variable 'a_year' set but not used
s3c24x0_rtc.c:67:38: warning: variable 'a_mon' set but not used
s3c24x0_rtc.c:67:30: warning: variable 'a_date' set but not used
s3c24x0_rtc.c:67:22: warning: variable 'a_hour' set but not used
s3c24x0_rtc.c:67:15: warning: variable 'a_min' set but not used
s3c24x0_rtc.c:67:8: warning: variable 'a_sec' set but not used
[-Wunused-but-set-variable]
Signed-off-by: Anatolij Gustschin <agust@denx.de>
* 'master' of git://git.denx.de/u-boot-arm:
Arm: re-introduce the MACH_TYPE_XXXXXX for EB_CPUX9K2 board
arm: jadecpu: Readd MACH_TYPE_JADECPU
at91: defined mach-types for otc570 board in board config file
at91: defined mach-types for meesc board in board config file
mx31pdk: Enable D and I caches
ehci-mxc: remove incorrect comment
README: Fix supported i.MX SoC list for CONFIG_MXC_SPI
mx53: Turn off child clocks before reconfigure perclk_root
qong: enable support for compressed images
imx: imx31_phycore.h: fix checkpatch warnings
vision2: Remove unused get_board_rev function
mx53smd: Remove unused get_board_rev function
mx53ard: Remove unused get_board_rev function
mx53evk: Remove unused get_board_rev function
mx53evk: Add RTC support
mx53loco: Remove unused get_board_rev function
mx53evk: Remove unneeded '1' from mx53evk.h
OMAP3: mvblx: Initial support for mvBlueLYNX-X
ARM: dig297: Define MACH_TYPE_OMAP3_CPS and CONFIG_MACH_TYPE
omap3: mem: Move comments next to definitions
omap3: mem: Clean-up whitespaces
omap3: mem: Define and use common macros
Davinci: ea20: added PREBOOT to configuration
Davinci: ea20: added I2C support
Davinci: ea20: added video support
VIDEO: davinci: add framebuffer to da8xx
ARM: Davinci: added missing registers to hardware.h
Davinci: ea20: add gpios for LCD backlight control
Davinci: ea20: add gpio for keeping power on in board_late_init
Davinci: ea20: Add default U-Boot environment
Davinci: ea20: Add early init to get early output from console
Davinci: ea20: Add NAND support
Davinci: ea20: set GPIOs to hold MII-Phy in reset and set UART0-Switch for console
Davinci: ea20: set console on UART0
arm, davinci: add cam_enc_4xx support
arm926ejs, davinci: add missing spi defines for dm365
arm926ejs, davinci: add cpuinfo for dm365
arm, davinci: add lowlevel function for dm365 soc
arm, davinci: add header files for dm365
spl, nand: add 4bit HW ecc oob first nand_read_page function
arm, davinci: add support for new spl framework
spl: add option for adding post memory test to the SPL framework
net, davinci_emac: make clock divider in MDIO control register configurable
arm, usb, davinci: make USBPHY_CTL register configurable
usb, davinci: add enable_vbus() weak function
omap3evm: fix errors caused by multiple definitions
omap3evm: Add (quick) configuration for NAND only
omap3evm: Add (quick) configuration for MMC/SD only
omap3evm: move common config options to new file
omap3evm: Prepare to split configuration
omap3evm: Reorder related config options
omap/spl: actually enable the console
davinci_emac: compilation fix, phy is array now
omap3evm: Set environment variable 'ethaddr'
arm, arm926: fix missing symbols in NAND_SPL mode
arm, davinci: Add function lpsc_syncreset()
arm, davinci: replace CONFIG_PRELOADER with CONFIG_SPL_BUILD
arm/km: portl2 environment address update to P1B
arm/km: adapt bootcounter evaluation
arm/km: enable jffs2 cmds
arm/km: trigger reconfiguration for the Xilinx FPGA
arm/km: add boardid and hwkey to kernel command line
ARM: Reintroduce MACH_TYPE_KM_KIRKWOOD for keymile ARM boards
netspace_v2: enable I2C EEPROM support
netspace_v2: fix SDRAM configuration
armada100: define CONFIG_SYS_CACHELINE_SIZE
pantheon: define CONFIG_SYS_CACHELINE_SIZE
kirkwood: define CONFIG_SYS_CACHELINE_SIZE
kirkwood: drop empty asm-offsets.s file
arm/km/mgcoge3un: enhance "waitforne" feature
arm/km: add variable waitforne to mgcoge3un
gplugD: Fix for error:MACH_TYPE_SHEEVAD undeclared
ARM: dreamplug: fix compilation
ARM: DockStar: fix compilation
ARM: netspace_v2: fix warnings
am335x: Drop board_sysinfo struct
am335x: Temporarily add MACH_TYPE define
misc:pmic:samsung Enable PMIC driver at C210 Universal target
dcache:s5p CONFIG_SYS_CACHELINE_SIZE added for s5p UNIVERSAL C210 target
dcache:s5p CONFIG_SYS_CACHELINE_SIZE added for s5p GONI target
smdkv310: use macro for mmc data read function address
smdkv310: use spl framework for mmc spl
SMDKV310: use get_ram_size() to validate dram size
SMDKV310: Initialize board id using CONFIG_MACH_TYPE
ORIGEN : use absolute paths and fix tool naming
ORIGEN : enable device tree support
MX25: tx25: Fix building due to missing MACH_TYPE
mx31: Add board support for HALE TT-01
mx31: add ESD control registers
mx31: define pins and init for UART2 and CSPI3
MX35: add support for flea3 board
MX51: vision2: add MACH_TYPE in config file
vision2: Remove unused header file
mx51evk: Remove unused get_board_rev function
mx51evk: Remove unneeded '1' from mx51evk.h
I2C: Fix mxc_i2c.c problem on imx31_phycore
mx35pdk: Add RTC support
mx51evk: Use GPIO API for configuring the IOMUX
mx51evk: Add RTC support
rtc: Make mc13783-rtc driver generic
qong: remove unneeded IOMUX settings
qong: Use mx31_set_gpr to setup USBH2 pins
mx31: Introduce mx31_set_gpr function
mx31pdk: Add MC13783 PMIC support
qong: remove unneeded "1" from qong.h
misc: pmic: fix regression in pmic_fsl.c (SPI)
mx5 configs: CONFIG_PRIME should really be CONFIG_ETHPRIME
MX35: Drop unnecessary prototypes from imx-regs.h
I2C: added I2C-2 and I2C-3 to MX35
MX35: factorize common assembly code
MX35: add reset cause as provided by other i.MX
MX35: add pins definition for UART3
MX35: added ESDC structure to imx-regs
Fix:
rv3029.c: In function 'rtc_set':
rv3029.c:98:6: warning: variable 'ret' set but not used
[-Wunused-but-set-variable]
rv3029.c: In function 'set_eere_bit':
rv3029.c:131:6: warning: variable 'ret' set but not used
[-Wunused-but-set-variable]
rv3029.c: In function 'wait_eebusy':
rv3029.c:149:9: warning: variable 'ret' set but not used
[-Wunused-but-set-variable]
rv3029.c: In function 'rtc_reset':
rv3029.c:165:6: warning: variable 'ret' set but not used
[-Wunused-but-set-variable]
Signed-off-by: Wolfgang Denk <wd@denx.de>
Fix:
ds3231.c: In function 'rtc_get':
ds3231.c:90:52: warning: variable 'control' set but not used
[-Wunused-but-set-variable]
Fix is done by switching to standard debug() instead of custom macro.
Signed-off-by: Wolfgang Denk <wd@denx.de>
Fix build issues:
mvrtc.c: In function 'rtc_get':
mvrtc.c:45: warning: implicit declaration of function 'readl'
mvrtc.c: In function 'rtc_set':
mvrtc.c💯 warning: implicit declaration of function 'writel'
dreamplug.c: In function 'board_early_init_f':
dreamplug.c:43: warning: implicit declaration of function 'kw_config_gpio'
dreamplug.c: In function 'board_init':
dreamplug.c:108: warning: implicit declaration of function 'kw_sdram_bar'
drivers/rtc/librtc.o: In function `rtc_set':
/home/ag/u-boot/u-boot-move-new-host/u-boot-video/drivers/rtc/mvrtc.c:92: undefined reference to `writel'
/home/ag/u-boot/u-boot-move-new-host/u-boot-video/drivers/rtc/mvrtc.c:103: undefined reference to `writel'
drivers/rtc/librtc.o: In function `rtc_reset':
/home/ag/u-boot/u-boot-move-new-host/u-boot-video/drivers/rtc/mvrtc.c:117: undefined reference to `readl'
/home/ag/u-boot/u-boot-move-new-host/u-boot-video/drivers/rtc/mvrtc.c:120: undefined reference to `readl'
drivers/rtc/librtc.o: In function `rtc_get':
/home/ag/u-boot/u-boot-move-new-host/u-boot-video/drivers/rtc/mvrtc.c:45: undefined reference to `readl'
/home/ag/u-boot/u-boot-move-new-host/u-boot-video/drivers/rtc/mvrtc.c:48: undefined reference to `readl'
...
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: Jason Cooper <u-boot@lakedaemon.net>
Cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
Acked-by: Marek Vasut <marek.vasut@gmail.com>
Rename mc13783-rtc so that it can be used for both MC13783 and MC13892 PMICs.
efikamx board, for example, does use a MC13892 PMIC, but the RTC selection is currently made as:
#define CONFIG_RTC_MC13783
,which is not very obvious.
Let the MC13783 and MC13892 RTC be selected by:
#define CONFIG_RTC_MC13XXX
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Stefano Babic <sbabic@denx.de>
Fix:
ds1337.c: In function 'rtc_get':
ds1337.c:88:52: warning: variable 'control' set but not used
[-Wunused-but-set-variable]
Signed-off-by: Wolfgang Denk <wd@denx.de>
There was a mix of UTF-8 and ISO-8859 files in the U-Boot source
tree, which could cause issues with the patchwork review system.
This commit converts all ISO-8859 files to UTF-8.
Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
This driver can be used for kirkwood SoCs by enabling CONFIG_RTC_MV. Tested on
Global Scale Technologies Dreamplug.
Signed-off-by: Jason Cooper <u-boot@lakedaemon.net>
Recieve/Receive
recieve/receive
Interupt/Interrupt
interupt/interrupt
Addres/Address
addres/address
Signed-off-by: Mike Williams <mike@mikebwilliams.com>
PT7C4338 chip is being manufactured by Pericom Technology Inc.
It is a serial real-time clock which provides:
1)Low-power clock/calendar.
2)Programmable square-wave output.
It has 56 bytes of nonvolatile RAM.
Signed-off-by: Priyanka Jain <Priyanka.Jain@freescale.com>
Acked-by: Timur Tabi <timur@freescale.com>
Before this commit, weak symbols were not overridden by non-weak symbols
found in archive libraries when linking with recent versions of
binutils. As stated in the System V ABI, "the link editor does not
extract archive members to resolve undefined weak symbols".
This commit changes all Makefiles to use partial linking (ld -r) instead
of creating library archives, which forces all symbols to participate in
linking, allowing non-weak symbols to override weak symbols as intended.
This approach is also used by Linux, from which the gmake function
cmd_link_o_target (defined in config.mk and used in all Makefiles) is
inspired.
The name of each former library archive is preserved except for
extensions which change from ".a" to ".o". This commit updates
references accordingly where needed, in particular in some linker
scripts.
This commit reveals board configurations that exclude some features but
include source files that depend these disabled features in the build,
resulting in undefined symbols. Known such cases include:
- disabling CMD_NET but not CMD_NFS;
- enabling CONFIG_OF_LIBFDT but not CONFIG_QE.
Signed-off-by: Sebastien Carlier <sebastien.carlier@gmail.com>
This patch adds generic support for the Samsung s3c2440 processor.
Global s3c24x0 changes to struct members converting from upper case to
lower case.
Signed-off-by: Craig Nauman <cnauman@diagraph.com>
Cc: kevin.morfitt@fearnside-systems.co.uk
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
Add missing codes according to original datasheet.
This patch also makes ftrtc010 could be adapted to PCLK and EXT_CLK.
Signed-off-by: Macpaul Lin <macpaul@andestech.com>
The AmigaOneG3SE board has been orphaned or a very long time, and
broken for more than 12 releases resp. more than 3 years. As nobody
seems to be interested any more in this stuff we may as well ged rid
of it, especially as it clutters many areas of the code so it is a
continuous pain for all kinds of ongoing work.
Signed-off-by: Wolfgang Denk <wd@denx.de>
The RTC is part of the Freescale's PMIC controller.
Use general function to access to PMIC internal registers.
Signed-off-by: Stefano Babic <sbabic@denx.de>
Tested-by: Magnus Lilja <lilja.magnus@gmail.com>
This patch adds a unified s3c24x0 cpu header file that selects the header
file for the specific s3c24x0 cpu from the SOC and CPU configs defined in
board config file. This removes the current chain of s3c24-type #ifdef's
from the s3c24x0 code.
Signed-off-by: Kevin Morfitt <kevin.morfitt@fearnside-systems.co.uk>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
This patch moves the s3c24x0 header files from include/ to
include/asm-arm/arch-s3c24x0/.
checkpatch.pl showed 2 errors and 3 warnings. The 2 errors were both due
to a non-UTF8 character in David M?ller's name:
ERROR: Invalid UTF-8, patch and commit message should be encoded in UTF-8
#489: FILE: include/asm-arm/arch-s3c24x0/s3c2410.h:3:
+ * David M?ller ELSOFT AG Switzerland. d.mueller@elsoft.ch
As David's name correctly contains a non-UTF8 character I haven't fixed
these errors.
The 3 warnings were all because of the use of 'volatile' in s3c24x0.h:
WARNING: Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt
#673: FILE: include/asm-arm/arch-s3c24x0/s3c24x0.h:35:
+typedef volatile u8 S3C24X0_REG8;
+typedef volatile u16 S3C24X0_REG16;
+typedef volatile u32 S3C24X0_REG32;
I'll fix these errors in another patch.
Tested by running MAKEALL for ARM8 targets and ensuring there were no new
errors or warnings.
Signed-off-by: Kevin Morfitt <kevin.morfitt@fearnside-systems.co.uk>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
This patch re-formats the arm920t s3c24x0 driver files, excluding the nand
driver, in preparation for changes to add support for the Embest SBC2440-II Board.
The changes are as follows:
- re-indent the code using Lindent
- make sure register layouts are defined using a C struct
- replace the upper-case typedef'ed C struct names with lower case
non-typedef'ed ones
- make sure registers are accessed using the proper accessor functions
- run checkpatch.pl and fix any error reports
It assumes the following patch has been applied first:
- [U-Boot][PATCH-ARM] CONFIG_SYS_HZ fix for ARM902T S3C24X0 Boards, 05/09/2009
- patches 1/4 and 2/4 of this series
Tested on an Embest SBC2440-II Board with local u-boot patches as I don't have
any s3c2400 or s3c2410 boards but need this patch applying before I can submit
patches for the SBC2440-II Board. Also, temporarily modified sbc2410x, smdk2400,
smdk2410 and trab configs to use the mtd nand driver (which isn't used by any
board at the moment), ran MAKEALL for all ARM9 targets and no new warnings or
errors were found.
Signed-off-by: Kevin Morfitt <kevin.morfitt@fearnside-systems.co.uk>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
This is needed to correctly start the charging of an attached capacitor
or battery.
Signed-off-by: Werner Pfister <werner.pfister@intercontrol.de>
Signed-off-by: Detlev Zundel <dzu@denx.de>
This RTC is used in some Calao boards. The driver code is taken from
the linux rtc-m41t94 driver
Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com>
In the process, also remove backward-compatiblity macros BIN_TO_BCD and
BCD_TO_BIN and update the sole board using them to use the new bin2bcd
and bcd2bin instead
Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Acked-by: Stefan Roese <sr@denx.de>
Acked-by: Detlev Zundel <dzu@denx.de>
The i.MX31 has three SPI buses and each bus has several chip selects
and the MC13783 chip can be connected to any of these. The current
RTC driver for MC13783 is hardcoded for CSPI2/SS2.
This patch makes make MC13783 SPI bus and chip select configurable
via CONFIG_MC13783_SPI_BUS and CONFIG_MC13783_SPI_CS.
Signed-off-by: Magnus Lilja <lilja.magnus@gmail.com>
Several source files need to be compiled and linked when one or more
config options are selected. To allow for easy selection in the
Makefiles yet to avoild multiple compilation (which costs build time)
and especially multiple linking (which causes errors), we use
"COBJS = $(sort COBJS-y)" which eliminates duplicates.
By courtesy of Detlev Zundel who suggested this approach.
Signed-off-by: Wolfgang Denk <wd@denx.de>
This "||" doesn't seem to work. Now using the idea suggest by Scott Wood
to combine both config options into one line. This even allows defining
both options and not generating the target object twice.
Signed-off-by: Stefan Roese <sr@denx.de>
This patch gets rid of the spi_chipsel table and adds a handful of new
functions that makes the SPI layer cleaner and more flexible.
Instead of the spi_chipsel table, each board that wants to use SPI
gets to implement three hooks:
* spi_cs_activate(): Activates the chipselect for a given slave
* spi_cs_deactivate(): Deactivates the chipselect for a given slave
* spi_cs_is_valid(): Determines if the given bus/chipselect
combination can be activated.
Not all drivers may need those extra functions however. If that's the
case, the board code may just leave them out (assuming they know what
the driver needs) or rely on the linker to strip them out (assuming
--gc-sections is being used.)
To set up communication parameters for a given slave, the driver needs
to call spi_setup_slave(). This returns a pointer to an opaque
spi_slave struct which must be passed as a parameter to subsequent SPI
calls. This struct can be freed by calling spi_free_slave(), but most
driver probably don't want to do this.
Before starting one or more SPI transfers, the driver must call
spi_claim_bus() to gain exclusive access to the SPI bus and initialize
the hardware. When all transfers are done, the driver must call
spi_release_bus() to make the bus available to others, and possibly
shut down the SPI controller hardware.
spi_xfer() behaves mostly the same as before, but it now takes a
spi_slave parameter instead of a spi_chipsel function pointer. It also
got a new parameter, flags, which is used to specify chip select
behaviour. This may be extended with other flags in the future.
This patch has been build-tested on all powerpc and arm boards
involved. I have not tested NIOS since I don't have a toolchain for it
installed, so I expect some breakage there even though I've tried
fixing up everything I could find by visual inspection.
I have run-time tested this on AVR32 ATNGW100 using the atmel_spi and
DataFlash drivers posted as a follow-up. I'd like some help testing
other boards that use the existing SPI API.
But most of all, I'd like some comments on the new API. Is this stuff
usable for everyone? If not, why?
Changed in v4:
- Build fixes for various boards, drivers and commands
- Provide common struct spi_slave definition that can be extended by
drivers
- Pass a struct spi_slave * to spi_cs_activate and spi_cs_deactivate
- Make default bus and mode build-time configurable
- Override default SPI bus ID and mode on mx32ads and imx31_litekit.
Changed in v3:
- Add opaque struct spi_slave for controller-specific data associated
with a slave.
- Add spi_claim_bus() and spi_release_bus()
- Add spi_free_slave()
- spi_setup() is now called spi_setup_slave() and returns a
struct spi_slave
- soft_spi now supports four SPI modes (CPOL|CPHA)
- Add bus parameter to spi_setup_slave()
- Convert the new i.MX32 SPI driver
- Convert the new MC13783 RTC driver
Changed in v2:
- Convert the mpc8xxx_spi driver and the mpc8349emds board to the
new API.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Tested-by: Guennadi Liakhovetski <lg@denx.de>
This commit gets rid of a huge amount of silly white-space issues.
Especially, all sequences of SPACEs followed by TAB characters get
removed (unless they appear in print statements).
Also remove all embedded "vim:" and "vi:" statements which hide
indentation problems.
Signed-off-by: Wolfgang Denk <wd@denx.de>
This patch fixes a problem with the month being read and written
incorrectly (offset by one). This only gets visible by also using
the Linux driver (rtc-m41t80).
Tested on AMCC Canyonlands.
Signed-off-by: Stefan Roese <sr@denx.de>
MC13783 is a multifunction IS with an SPI interface to the host. This
driver handles the RTC controller in this chip.
Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
The default settings for RTC DS1337 keeps the OSC
output, 32,768 Hz, on. This add CFG_RTC_DS1337_NOOSC to
turn it off.
Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Modify the RTC API to provide one a status for the time reported by
the rtc_get() function:
0 - a reliable time is guaranteed,
< 0 - a reliable time isn't guaranteed (power fault, clock issues,
and so on).
The RTC chip drivers are responsible for providing this info if the
corresponding chip supports such functionality. If not - always
report that the time is reliable.
The POST RTC test was modified to detect the RTC faults utilizing
this new rtc_get() feature.
Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
This driver is based on the driver for the M41T11. In the intended
application, the RTC will be powered by a large capacitor, rather than a
battery. The driver therefore checks to see whether the RTC has lost
power. The chip's OUT bit is normally reset from its power-up state. If
the OUT bit is read as set, or if the date and time are not valid, then the
RTC is assumed to have lost power, and its date and time are reset to
1900-01-01 00:00:00.
Support for adjusting the speed of the clock to improve accuracy is
provided through an environment variable.
Signed-off-by: Larry Johnson <lrj@acm.org>
