From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
This patch series add support for the NXP RTC hardware module present on
S32G2/S32G3 SoCs.
RTC tracks clock time during system suspend. It is used as a time-based
wakeup source for the S32G2/S32G3 SoCs.
RTC is not battery-powered and it is not kept alive during system reset.
Following is an example of Suspend to RAM trigger on S32G2/S32G3 SoCs,
using userspace tools such as rtcwake:
# rtcwake -s 2 -m mem
# rtcwake: assuming RTC uses UTC ...
# rtcwake: wakeup from "mem" using /dev/rtc0 at Wed Feb 6 06:28:36 2036
#
Changes in V5:
- Removed rollover support.
- Removed clock switching support between Runtime and Suspend. A clock source
which is always available has been used instead.
- Enabled 512 value RTC hardware frequency divisor to achieve higher rollover
time
- Removed unneeded 'remove' callback.
- Decreased driver print verbosity on error paths.
- Provided 'clock-names' actual names in bindings documentation
- Remove __maybe_unused notations. Used the DEFINE_SIMPLE_DEV_PM_OPS() and
pm_sleep_ptr() macros to handle the .suspend/.resume callbacks.
- Fixed some alignment issues.
Changes in V4:
- Dropped 'assigned-*' clock management approach. Simplified RTC Runtime
and Suspend/Standby clock configuration.
- Simplified error paths on probe function
- Removed node label from bindings example
- Several cosmetic coding style fixes
Changes in V3:
- Removed 'nxp,s32g3-rtc' compatible string
- Change to 'remove' callback from 'remove_new'
- Used 'dev.parent' from 'struct rtc_device' instead of defining a
specific 'struct device' in driver data
- Fixed several errors reported by kernel test robot
- Removed 'assigned-clocks', 'assigned-clock-parents' and
'assigned-clock-rates' from required properties in the binding
documentation.
- Refactored S32G RTC driver such that a default clock source and
divisors configuration will be applied in case 'assigned-clocks' and
'assigned-clock-parents' properties are missing.
Changes in V2:
- Removed 'clksel' support from dts bindings. Used clock parents support
from CCF to better illustrate the RTC hardware IP from S32G2/S32G3.
- Removed frequency dividers support from dts bindings. Used assigned
clock frequencies support from CCF instead.
- Reduced the interval while RTC is voluntarily disabled to a simple
register write in order to avoid any race condition between a possbile
rollover and 'suspend' callback execution flow.
- Updated bindings documentation with respect to clocking support.
- Fixed a potential unused variable warning reported by kernel test robot.
- Updated to usage of 'devm_rtc_allocate_device' and 'devm_rtc_register_device'
instead of deprecated 'devm_rtc_device_register'.
Ciprian Marian Costea (4):
dt-bindings: rtc: add schema for NXP S32G2/S32G3 SoCs
rtc: s32g: add NXP S32G2/S32G3 SoC support
arm64: defconfig: add S32G RTC module support
MAINTAINERS: add NXP S32G RTC driver
.../devicetree/bindings/rtc/nxp,s32g-rtc.yaml | 69 +++
MAINTAINERS | 2 +
arch/arm64/configs/defconfig | 1 +
drivers/rtc/Kconfig | 11 +
drivers/rtc/Makefile | 1 +
drivers/rtc/rtc-s32g.c | 554 ++++++++++++++++++
6 files changed, 638 insertions(+)
create mode 100644 Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml
create mode 100644 drivers/rtc/rtc-s32g.c
--
2.45.2