treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_30.RULE (part 2)

Based on the normalized pattern:

this program is free software you can redistribute it and/or modify it
under the terms of the gnu general public license as published by the
free software foundation version 2 this program is distributed as is
without any warranty of any kind whether express or implied without
even the implied warranty of merchantability or fitness for a
particular purpose see the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference.

Reviewed-by: Allison Randal <allison@lohutok.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

soc: ti: wkup_m3_ipc: Add debug option to halt m3 in suspend

Add a debugfs option to allow configurable halting of the wkup_m3
during suspend at the last possible point before low power mode entry.
This condition can only be resolved through JTAG and advancing beyond
the while loop in a8_lp_ds0_handler [1]. Although this hangs the system
it forces the system to remain active once it has been entirely
configured for low power mode entry, allowing for register inspection
through JTAG to help in debugging transition errors.

Halt mode can be set using the enable_off_mode entry under wkup_m3_ipc
in the debugfs.

[1] https://git.ti.com/cgit/processor-firmware/ti-amx3-cm3-pm-firmware/tree/src/pm_services/pm_handlers.c?h=08.02.00.006#n141

Suggested-by: Brad Griffis <bgriffis@ti.com>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
[dfustini: add link for a8_lp_ds0_handler() in ti-amx3-cm3-pm-firmware]
Signed-off-by: Drew Fustini <dfustini@baylibre.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Link: https://lore.kernel.org/r/20220502033211.1383158-1-dfustini@baylibre.com

soc: ti: wkup_m3_ipc: Add support for i2c voltage scaling

Allow loading of a binary containing i2c scaling sequences to be
provided to the wkup_m3 firmware in order to properly scale voltage
rails on the PMIC during low power modes like DeepSleep0. Proper binary
format is determined by the FW in use.

Code expects firmware to have 0x0C57 present as the first two bytes
followed by one byte defining offset to sleep sequence followed by one
byte defining offset to wake sequence and then lastly both sequences.
Each sequence is a series of I2C transfers in the form:

u8 length | u8 chip address | u8 byte0/reg address | u8 byte1 | u8 byteN
..

The length indicates the number of bytes to transfer, including the
register address. The length of each transfer is limited by the I2C
buffer size of 32 bytes.

Based on previous work by Russ Dill.

[dfustini: replace FW_ACTION_HOTPLUG with FW_ACTION_UEVENT]

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
[dfustini: add NULL argument to rproc_da_to_va() call]
Signed-off-by: Drew Fustini <dfustini@baylibre.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Link: https://lore.kernel.org/r/20220426200741.712842-3-dfustini@baylibre.com

soc: ti: wkup_m3_ipc: Add support for IO Isolation

AM43xx support isolation of the IOs so that control is taken
from the peripheral they are connected to and overridden by values
present in the CTRL_CONF_* registers for the pad in the control module.

The actual toggling happens from the wkup_m3, so use a DT property from
the wkup_m3_ipc node to allow the PM code to communicate the necessity
for placing the IOs into isolation to the firmware.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Drew Fustini <dfustini@baylibre.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Link: https://lore.kernel.org/r/20220414192722.2978837-3-dfustini@baylibre.com

soc: ti: wkup_m3_ipc: Add support for toggling VTT regulator

Some boards like the AM335x EVM-SK and AM437x GP EVM provide software
control via a GPIO pin to toggle the DDR VTT regulator to reduce power
consumption in low power states.

The VTT regulator should be disabled after enabling self-refresh on
suspend, and should be enabled before disabling self-refresh on resume.
This is to allow proper self-refresh entry/exit commands to be
transmitted to the memory.

The "ti,vtt-gpio-pin" device tree property in the wkup_m3_ipc node
specifies which GPIO pin to use. This property is communicated to the
Wakeup Cortex M3 co-processor where the actual toggling of the GPIO pin
happens in CM3 firmware [1].

Please note that the GPIO pin must be on the GPIO0 module as that module
is in the wakeup power domain.

[1] https://git.ti.com/cgit/processor-firmware/ti-amx3-cm3-pm-firmware/tree/src/pm_services/ddr.c?h=08.02.00.006#n190

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
[dfustini: remove the unnecessary "ti,needs-vtt-toggle" property]
Signed-off-by: Drew Fustini <dfustini@baylibre.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Link: https://lore.kernel.org/r/20220409211215.2529387-3-dfustini@baylibre.com

include/: replace HTTP links with HTTPS ones

Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/20200726110117.16346-1-grandmaster@al2klimov.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

soc: ti: wkup_m3_ipc: Add wkup_m3_request_wake_src

Add wkup_m3_request_wake_src to allow users to get the name of
the wakeup source after a DeepSleep or Standby transition.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>

soc: ti: wkup_m3_ipc: Add rtc_only with ddr in self refresh mode support

Adds rtc_only support. This needs resume function to shutdown and
reboot the m3.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>

soc: ti: Add wkup_m3_ipc driver

Introduce a wkup_m3_ipc driver to handle communication between the MPU
and Cortex M3 wkup_m3 present on am335x.

This driver is responsible for actually booting the wkup_m3_rproc and
also handling all IPC which is done using the IPC registers in the control
module, a mailbox, and a separate interrupt back from the wkup_m3. A small
API is exposed for executing specific power commands, which include
configuring for low power mode, request a transition to a low power mode,
and status info on a previous transition.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>