spi: fsl: Remove unused extern declarations

commit b36ece832512 ("spi/mpc8xxx: refactor the common code for SPI/eSPI controller")
left mpc8xxx_spi_bufs() behind.
And since commit 3c5395b66ff6 ("spi: fsl-(e)spi: simplify cleanup code")
mpc8xxx_spi_remove() is not used anymore.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20230725135411.21152-1-yuehaibing@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl: Convert to use CS GPIO descriptors

This converts the Freescale SPI master driver to use GPIO
descriptors for chip select handling.

The Freescale (fsl) driver has a lot of quirks to look up
"gpios" rather than "cs-gpios" from the device tree.
After the prior patch that will make gpiolib return the
GPIO descriptor for "gpios" in response to a request for
"cs-gpios", this code can be cut down quite a bit.

The driver has custom handling of chip select rather
than using the core (which may be possible but not
done in this patch) so it still needs to refer directly
to spi->cs_gpiod to set the chip select.

Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP Linux Team <linux-imx@nxp.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20190804003539.985-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

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 as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spi: spi-fsl-spi: support use of the SPISEL_BOOT signal on MPC8309

The MPC8309 has a dedicated signal, SPISEL_BOOT, usually used as chip
select for the flash device from which the bootloader is loaded. It is
not an ordinary gpio, but is simply controlled via the SPI_CS register
in the system configuration.

To allow accessing such a spi slave, we need to teach
fsl_spi_cs_control() how to control the SPISEL_BOOT signal. To
distinguish the gpio-controlled slaves, continue to have those use
chip_select values of 0..ngpios-1, and use chip_select == ngpios for
the boot flash.

I'm not too happy with all the ifdeffery, but it seems to be necessary
for guarding the sysdev/fsl_soc.h and use of
get_immrbase() (spi-fsl-lib.c already contains similar ifdeffery).

Googling suggests that the MPC8306 is similar, with the SPI_CS
register at the same offset.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-espi: separate fsl-espi from fsl-lib completely

After having removed all code dependencies we can make fsl-espi
completely independent of fsl-lib now.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-espi: add support for ESPI RXSKIP mode

This patch adds support for ESPI RXSKIP mode. This mode is optimized
for flash reads:
- sends a number of bytes and then reads a number of bytes
- shifts out zeros automatically when reading

Supporting RXSKIP mode is a prerequisite for supporting dual output
read mode.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-espi: Rename len in struct mpc8xxx_spi to rx_len and make it unsigned

Now that we introduced element tx_len in struct mpc8xxx_spi let's
rename element len to rx_len as it actually is the number of bytes to
receive. In addition make it unsigned.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-espi: fix and improve writing to TX FIFO

This change addresses two issues:
- If the TX FIFO is full the ISR polls until there's free space again.
An ISR should never wait for something.
- Currently the number of bytes to transfer is rounded up to the next
multiple of 4. For most transfers therefore few bytes remain in the
TX FIFO after end of transfer.
This would cause the next transfer to fail and as a workaround the
ESPI block is disabled / re-enabled in fsl_espi_change_mode.
This seems to clear the FIFO's (although it's not mentioned in the
spec).

With this change the TX FIFO is filled as much as possible initially
and whenever the ISR is called. Also the exact number of bytes is
transferred.
The spinlock protects against a potential race if the first interrupt
occurs whilst the TX FIFO is still being initially filled.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-espi: align register access with other drivers

Change register access to the method used in other drivers too.
- use register names as in the chip spec for constants
- avoid hard to read statements like
__be32 __iomem *espi_mode = &reg_base->mode
- get rid of old powerpc-specific functions like in_8

In addition annotate reg_base in struct mpc8xxx_spi as __iomem.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-espi: pre-allocate message buffer

Currently the driver allocates a 64kb buffer for each single message.
On systems with little and fragmented memory this can result in
memory allocation errors. Solve this by pre-allocating a buffer.

This patch was developed in OpenWRT long ago, however it never
made it upstream.

I slightly modified the original patch to re-initialize the buffer
at the beginning of each transfer.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-(e)spi: simplify cleanup code

Now that most cleanup is done automatically the remove functions
can be significantly simplified.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-(e)spi: Support compile as module

Signed-off-by: Esben Haabendal <eha@deif.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-(e)spi: migrate to generic master queueing

Migrates the fsl-(e)spi driver to use the generic master queuing.
Avoids the "master is unqueued, this is deprecated" warning.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl: Kill mpc8xxx_spi_cleanup and convert fsl_espi_setup to use devm_kzalloc

In current code, master->cleanup and master->setup are not set in the same
function. This makes it hard to read and not good for code maintain.
One example is in fsl-spi.c, master->cleanup is overrided in mpc8xxx_spi_probe()
which leads to a memory leak.

This patch removes mpc8xxx_spi_cleanup() and converts fsl_espi_setup to use
devm_kzalloc so we don't need to take care of freeing memory.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi/spi-fsl-spi: Add support for gpio chipselects for GRLIB type cores

This relies upon of_spi_register_master to find out which gpios to use.

Acked-by: Anton Vorontsov <anton@enomsg.org>
Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

spi/spi-fsl-spi: Add support for setting a maximum number of bits per word

Acked-by: Anton Vorontsov <anton@enomsg.org>
Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

spi/spi-fsl-spi: Introduce a type for the driver

For being able to distinguishing between the regular type of cores and others
with different entries in of_fsl_spi_match.

Acked-by: Anton Vorontsov <anton@enomsg.org>
Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

spi/spi-fsl-spi: Move setting non-zero tx and rx shifts to a function accessed by a function pointer

Acked-by: Anton Vorontsov <anton@enomsg.org>
Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

spi/spi-fsl-spi: Make driver usable in CPU mode outside of an FSL_SOC environment

This makes the spi-fsl-spi driver usable in CPU mode outside of an FSL_SOC and
even an powerpc environment by moving CPM mode functionality to a separate file
that is only compiled and linked in an FSL_SOC environment and adding some
ifdefs to hide types and functions or provide alternatives.

For devicetree probing a "clock-frequency" property is used for clock frequency
instead of calls to FSL_SOC-specific functions.

Acked-by: Anton Vorontsov <anton@enomsg.org>
Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

spi: reorganize drivers

Sort the SPI makefile and enforce the naming convention spi_*.c for
spi drivers.

This change also rolls the contents of atmel_spi.h into the .c file
since there is only one user of that particular include file.

v2: - Use 'spi-' prefix instead of 'spi_' to match what seems to be
be the predominant pattern for subsystem prefixes.
- Clean up filenames in Kconfig and header comment blocks

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>