[PATCH v3 0/6] I2C framework, reboot Unmatched via PMIC

[Nikita Shubin]

From: Nikita Shubin <n.shubin at yadro.com>

This series introduce rebooting via i2c da9063 PMIC, currently on
SiFive Unmatched board.

"gpio-poweroff", "gpio-reset" remains with default priority of 128 - default priority,
da9063 is 1 by default the least priority for shutdown and highest priority for
reset.

da9063 resides in platform/generic code and is used only for sifive_fu740, in case if 
da9063 is found in device tree.

Alexandre, Heinrich and Anup, the reason of "da9063_system_reset: chip is not 
da9063 PMIC" wasn't the initialization, the peripheral clocks are initiated by ZSBL,
the reason was incorrect timeouts in sifive_i2c_adapter_poll (100ms is really too much, 
my bad), with polling reworked everything is working smooth regardless of 
last reset type.

The RTC ALARM reboot seems working, but implementing it in OpenSBI will require a 
full-scale calendar logic (for day/month correct rollover) which is undesirable, also 
we sacrifice the ability to wake up on ALARM.

I am currently experimentings with TICK ALARM approach which should behave just like 
the ALARM one, but i get wierd results with board being powered off and then preventing 
the onKEY power it back again (turns off shortly after key pressed), 
until cable plugged/unplugged (the BATTERY is missing).

It looks like OTP settings are messing with logic, a comment from SiFive is really 
needed.

So we should currently stick to approuch proposed by Alexandre it hasn't failed 
me so far.

v2->v3:
- new "lib: utils/reset: separate driver init func" patch
- dropped separate DT bindings for da9063
- dropped priority bindings
- moved fdt_reset_da9063 to generic platform code
- fdt_reset_da9063 is instatated by sifive_fu740 final init

Alexandre Ghiti:
- removed fdt_i2c_adapter_driver
- fixed sifive_i2c_setreg/sifive_i2c_getreg to use uint8_t for reg
- dropped configure method
- dropped unneeded register's defines

Nikita Shubin (6):
  lib: utils/reset: add priority to gpio reset
  lib: utils/reset: separate driver init func
  lib: utils/i2c: Add generic I2C configuration library
  lib: utils/i2c: Add simple FDT based I2C framework
  lib: utils/i2c: Add minimal SiFive I2C driver
  platform: sifive_fu740: add platform reset driver

 include/sbi_utils/i2c/fdt_i2c.h     |  26 +++
 include/sbi_utils/i2c/i2c.h         |  85 +++++++++
 include/sbi_utils/reset/fdt_reset.h |   5 +
 lib/utils/i2c/fdt_i2c.c             |  90 ++++++++++
 lib/utils/i2c/fdt_i2c_sifive.c      | 262 ++++++++++++++++++++++++++++
 lib/utils/i2c/i2c.c                 |  75 ++++++++
 lib/utils/i2c/objects.mk            |  12 ++
 lib/utils/reset/fdt_reset.c         |  37 ++--
 lib/utils/reset/fdt_reset_gpio.c    |  10 +-
 platform/generic/fdt_reset_da9063.c | 186 ++++++++++++++++++++
 platform/generic/objects.mk         |   1 +
 platform/generic/sifive_fu740.c     |  22 +++
 12 files changed, 793 insertions(+), 18 deletions(-)
 create mode 100644 include/sbi_utils/i2c/fdt_i2c.h
 create mode 100644 include/sbi_utils/i2c/i2c.h
 create mode 100644 lib/utils/i2c/fdt_i2c.c
 create mode 100644 lib/utils/i2c/fdt_i2c_sifive.c
 create mode 100644 lib/utils/i2c/i2c.c
 create mode 100644 lib/utils/i2c/objects.mk
 create mode 100644 platform/generic/fdt_reset_da9063.c

-- 
2.31.1