From: Ciprian Marian Costea <ciprianmarian.costea@xxxxxxxxxxx> 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
