memory: ti-emif-pm: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/c69f64ad0e89fe2a37b281d44ebfb55b565b50bf.1702822744.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

memory: ti-emif-pm: Use device_get_match_data() to simplify the code

Directly get the match data with device_get_match_data().

Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn>
Link: https://lore.kernel.org/r/202211171939327684154@zte.com.cn
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

memory: ti-emif-pm: simplify platform_get_resource()

Use devm_platform_get_and_ioremap_resource() instead of
platform_get_resource() and devm_ioremap_resource().

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220419142859.380566-4-krzysztof.kozlowski@linaro.org

memory: ti-emif-pm: Drop of_match_ptr from of_device_id table

The driver can match only via the DT table so the table should be always
used and the of_match_ptr does not have any sense (this also allows ACPI
matching via PRP0001, even though it might be not relevant here). This
fixes compile warning (!CONFIG_OF with clang):

drivers/memory/ti-emif-pm.c:238:34: warning:
unused variable 'ti_emif_of_match' [-Wunused-const-variable]

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20210206111343.19273-1-krzk@kernel.org

memory: ti-emif-pm: Fix cast to iomem pointer

Cast pointer to iomem memory properly to fix sparse warning:

drivers/memory/ti-emif-pm.c:251:38: warning: incorrect type in argument 1 (different address spaces)
drivers/memory/ti-emif-pm.c:251:38: expected void const volatile [noderef] __iomem *addr
drivers/memory/ti-emif-pm.c:251:38: got void *

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty 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 in 655 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

memory: ti-emif-sram: Add ti_emif_run_hw_leveling for DDR3 hardware leveling

In certain situations, such as when returning from low power modes, the
EMIF must re-run hardware leveling to properly restore DDR3 access.

This is accomplished by introducing a new ti-emif-sram-pm call,
ti_emif_run_hw_leveling, to check if DDR3 is in use and if so, trigger
the full write and read leveling processes.

Suggested-by: Brad Griffis <bgriffis@ti.com>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>

memory: ti-emif-sram: Add resume function to recopy sram code

After an RTC+DDR cycle we lose sram context so emif pm functions present
in sram are lost. We can check if the first byte of the original
code in DDR contains the same first byte as the code in sram, and if
they do not match we know we have lost context and must recopy the
functions to the previous address to maintain PM functionality.

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>

memory: ti-emif-sram: remove redundant dev_err call in ti_emif_probe()

There is a error message within devm_ioremap_resource
already, so remove the dev_err call to avoid redundant
error message.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>

memory: ti-emif-sram: remove unused variable

The newly introduced driver causes a harmless warning for a variable
that was evidently never used:

drivers/memory/ti-emif-pm.c: In function 'ti_emif_remove':
drivers/memory/ti-emif-pm.c:303:17: error: unused variable 'dev' [-Werror=unused-variable]

Fixes: 8428e5ad750d ("memory: ti-emif-sram: introduce relocatable suspend/resume handlers")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>

memory: ti-emif-sram: introduce relocatable suspend/resume handlers

Certain SoCs like Texas Instruments AM335x and AM437x require parts
of the EMIF PM code to run late in the suspend sequence from SRAM,
such as saving and restoring the EMIF context and placing the memory
into self-refresh.

One requirement for these SoCs to suspend and enter its lowest power
mode, called DeepSleep0, is that the PER power domain must be shut off.
Because the EMIF (DDR Controller) resides within this power domain, it
will lose context during a suspend operation, so we must save it so we
can restore once we resume. However, we cannot execute this code from
external memory, as it is not available at this point, so the code must
be executed late in the suspend path from SRAM.

This patch introduces a ti-emif-sram driver that includes several
functions written in ARM ASM that are relocatable so the PM SRAM
code can use them. It also allocates a region of writable SRAM to
be used by the code running in the executable region of SRAM to save
and restore the EMIF context. It can export a table containing the
absolute addresses of the available PM functions so that other SRAM
code can branch to them. This code is required for suspend/resume on
AM335x and AM437x to work.

In addition to this, to be able to share data structures between C and
the ti-emif-sram-pm assembly code, we can automatically generate all of
the C struct member offsets and sizes as macros by processing
emif-asm-offsets.c into assembly code and then extracting the relevant
data as is done for the generated platform asm-offsets.h files.

Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>