This series introduces necessary ti_sci driver functionality in preparation of supporting DeepSleep mode for suspend to mem on TI K3 AM62x. This version is a fixup and rebase of the patch series by Dave Gerlach [1]. It applies on top of v6.1-rc4. Deep Sleep mode is described in section "5.2.4.4 DeepSleep" of the AM62x Technical Reference Manual [2]. The kernel triggers entry to Deep Sleep mode through the mem suspend transition with the following: * Use a TF-A binary that supports PSCI_SYSTEM_SUSPEND call. This causes system to use PSCI system suspend as last step of mem sleep. * The firmware requires that the OS sends a TISCI_MSG_PREPARE_SLEEP message in order to provide details about suspend, so we must add the ability to send this message. We also add TISCI_MSG_LPM_WAKE_REASON and TISCI_MSG_SET_IO_ISOLATION messages as part of a new PM ops. These messages are part of the TISCI PM Low Power Mode API [3]. (Patch 2) * A memory address must be provided to the firmware using the above message, which is allocated and managed by dma_alloc_coherent() and friends. (Patch 3) * System must load firmware to a specific location before Deep Sleep is entered, and this is accomplished using a memory region in device tree to indicate where this firmware should be loaded, and also a "firmware-name" property to indicate the name of the firmware to load. The ti_sci driver checks in its pm handler to see if the firmware has been loaded and if not, loads it. (Patch 4) * Finally, the ti_sci driver must actually send TISCI_MSG_PREPARE_SLEEP message to firmware with the above information included, which it does during the driver suspend handler when PM_MEM_SUSPEND is the determined state being entered. (Patch 5) This is tested on am625-sk using a limited dts with all devices disabled apart from cpu0, main_uart0, i2c, rtc, mmc/sd, dmsc, and secure_proxy_main. Testing this sequence requires K3 sdhci suspend/resume support [4], enable the wkup_rtc in the am625-sk.dts, disable devices that don't support system suspend/resume like OSPI and CPSW3G. In can be tested on the following branch: https://github.com/gvlaev/linux/tree/upstream-v6.2/lpm-ti-sci-v1 Changelog: v2: - Addressed comments received for v1 series [1]. - Updated v1 patch 5 to use pm notifier to avoid firmware loading issues. - Dropped the reserved region requirement and allocate DMA memory instead. The reserved region binding patch is also removed. - Introduce two more TISCI LPM messages that are supported in SysFW. - Fixes in error handling. [1] https://lore.kernel.org/lkml/20220421203659.27853-1-d-gerlach@xxxxxx [2] https://www.ti.com/lit/pdf/spruiv7 [3] https://software-dl.ti.com/tisci/esd/latest/2_tisci_msgs/pm/lpm.html [4] https://lore.kernel.org/lkml/20220408124338.27090-1-a-govindraju@xxxxxx Dave Gerlach (5): dt-bindings: ti, sci: Add lpm region and firmware-name firmware: ti_sci: Introduce Power Management Ops firmware: ti_sci: Allocate memory for the LPM modes firmware: ti_sci: Use dt provided fw name and address to load at suspend time firmware: ti_sci: Introduce prepare system suspend call .../bindings/arm/keystone/ti,sci.yaml | 21 +- drivers/firmware/ti_sci.c | 356 ++++++++++++++++++ drivers/firmware/ti_sci.h | 64 +++- include/linux/soc/ti/ti_sci_protocol.h | 44 +++ 4 files changed, 480 insertions(+), 5 deletions(-) base-commit: f0c4d9fc9cc9462659728d168387191387e903cc -- 2.30.2
