spi: aspeed: Use helper function devm_clk_get_enabled()

Since commit 7ef9651e9792 ("clk: Provide new devm_clk helpers for prepared
and enabled clocks"), devm_clk_get() and clk_prepare_enable() can now be
replaced by devm_clk_get_enabled() when driver enables (and possibly
prepares) the clocks for the whole lifetime of the device. Moreover, it is
no longer necessary to unprepare and disable the clocks explicitly.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Chin-Ting Kuo <chin-ting_kuo@aspeedtech.com>
Signed-off-by: Li Zetao <lizetao1@huawei.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Link: https://lore.kernel.org/r/20230823133938.1359106-4-lizetao1@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: aspeed: switch to use modern name

Change legacy name master to modern name host or controller.

No functional changed.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20230728093221.3312026-3-yangyingliang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: Replace all spi->chip_select and spi->cs_gpiod references with function call

Supporting multi-cs in spi drivers would require the chip_select & cs_gpiod
members of struct spi_device to be an array. But changing the type of these
members to array would break the spi driver functionality. To make the
transition smoother introduced four new APIs to get/set the
spi->chip_select & spi->cs_gpiod and replaced all spi->chip_select and
spi->cs_gpiod references with get or set API calls.
While adding multi-cs support in further patches the chip_select & cs_gpiod
members of the spi_device structure would be converted to arrays & the
"idx" parameter of the APIs would be used as array index i.e.,
spi->chip_select[idx] & spi->cs_gpiod[idx] respectively.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
Acked-by: Heiko Stuebner <heiko@sntech.de> # Rockchip drivers
Reviewed-by: Michal Simek <michal.simek@amd.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org> # Aspeed driver
Reviewed-by: Dhruva Gole <d-gole@ti.com> # SPI Cadence QSPI
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com> # spi-stm32-qspi
Acked-by: William Zhang <william.zhang@broadcom.com> # bcm63xx-hsspi driver
Reviewed-by: Serge Semin <fancer.lancer@gmail.com> # DW SSI part
Link: https://lore.kernel.org/r/167847070432.26.15076794204368669839@mailman-core.alsa-project.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: aspeed-smc: 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 (mostly) ignored
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.

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>
Acked-by: Cédric Le Goater <clg@kaod.org>
Link: https://lore.kernel.org/r/20230303172041.2103336-4-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: aspeed: Use devm_platform_{get_and_}ioremap_resource()

Use the devm_platform_{get_and_}ioremap_resource() helper instead of
calling platform_get_resource() and devm_ioremap_resource() separately.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20221019092635.1176622-1-yangyingliang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: aspeed: Fix window offset of CE1

The offset value of the mapping window in the kernel structure is
calculated using the value of the previous window offset. This doesn't
reflect how the HW is configured and can lead to erroneous setting of
the second flash device (CE1).

Cc: Chin-Ting Kuo <chin-ting_kuo@aspeedtech.com>
Fixes: e3228ed92893 ("spi: spi-mem: Convert Aspeed SMC driver to spi-mem")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20221016155722.3520802-1-clg@kaod.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: aspeed: Fix typo in mode_bits field for AST2600 platform

Both quad SPI TX and RX modes can be supported on AST2600.
Correct typo in mode_bits field in both ast2600_fmc_data
and ast2600_spi_data structs.

Signed-off-by: Chin-Ting Kuo <chin-ting_kuo@aspeedtech.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Link: https://lore.kernel.org/r/20221005083209.222272-1-chin-ting_kuo@aspeedtech.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: aspeed: Remove redundant dev_err call

devm_ioremap_resource() prints error message in itself. Remove the
dev_err call to avoid redundant error message.

Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Link: https://lore.kernel.org/r/20220923101632.19170-1-shangxiaojing@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: aspeed: Fix division by zero

When using the normal read operation for data transfers, the dummy bus
width is zero. In that case, they are no dummy bytes to transfer and
setting the dummy field in the controller register becomes useless.

Issue was found on a custom "Bifrost" board based on the AST2500 SoC
and using a MX25L51245GMI-08G SPI Flash.

Reported-by: Ian Woloschin <ian.woloschin@akamai.com>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Tested-by: Ian Woloschin <iwolosch@akamai.com>
Fixes: 9da06d7bdec7dad80 ("spi: aspeed: Add support for direct mapping")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Link: https://lore.kernel.org/r/20220622161617.3719096-3-clg@kaod.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: aspeed: Add dev_dbg() to dump the spi-mem direct mapping descriptor

The default value of the control register is set using the direct
mapping information passed to the ->dirmap_create() handler. Dump the
mapping range and the SPI memory operation characteristics to analyze
how the register value has been computed.

spi-aspeed-smc 1e630000.spi: CE0 read dirmap [ 0x00000000 - 0x04000000 ] OP 0x6c mode:1.1.1.4 naddr:0x4 ndummies:0x1
...
spi-aspeed-smc 1e630000.spi: CE0 write dirmap [ 0x00000000 - 0x04000000 ] OP 0x12 mode:1.1.0.1 naddr:0x4 ndummies:0x0

Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20220622161617.3719096-2-clg@kaod.org
Signed-off-by: Mark Brown <broonie@kernel.org>

mtd: spi-nor: aspeed: set the decoding size to at least 2MB for AST2600

In AST2600, the unit of SPI CEx decoding range register is 1MB, and end
address offset is set to the acctual offset - 1MB. If the flash only has
1MB, the end address will has same value as start address, which will
causing unexpected errors.

This patch set the decoding size to at least 2MB to avoid decoding errors.

Tested:
root@bletchley:~# dmesg | grep "aspeed-smc 1e631000.spi: CE0 window"
[ 59.328134] aspeed-smc 1e631000.spi: CE0 window resized to 2MB (AST2600 Decoding)
[ 59.343001] aspeed-smc 1e631000.spi: CE0 window [ 0x50000000 - 0x50200000 ] 2MB
root@bletchley:~# devmem 0x1e631030
0x00100000

Tested-by: Jae Hyun Yoo <quic_jaehyoo@quicinc.com>
Signed-off-by: Potin Lai <potin.lai@quantatw.com>
[ clg : Ported on new spi-mem driver ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Link: https://lore.kernel.org/r/20220509175616.1089346-12-clg@kaod.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: aspeed: Calibrate read timings

To accommodate the different response time of SPI transfers on different
boards and different SPI NOR devices, the Aspeed controllers provide a
set of Read Timing Compensation registers to tune the timing delays
depending on the frequency being used. The AST2600 SoC has one of these
registers per device. On the AST2500 and AST2400 SoCs, the timing
register is shared by all devices which is problematic to get good
results other than for one device.

The algorithm first reads a golden buffer at low speed and then performs
reads with different clocks and delay cycle settings to find a breaking
point. This selects a default good frequency for the CEx control register.
The current settings are a bit optimistic as we pick the first delay giving
good results. A safer approach would be to determine an interval and
choose the middle value.

Calibration is performed when the direct mapping for reads is created.
Since the underlying spi-nor object needs to be initialized to create
the spi_mem operation for direct mapping, we should be fine. Having a
specific API would clarify the requirements though.

Cc: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Tested-by: Joel Stanley <joel@jms.id.au>
Tested-by: Tao Ren <rentao.bupt@gmail.com>
Tested-by: Jae Hyun Yoo <quic_jaehyoo@quicinc.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Link: https://lore.kernel.org/r/20220509175616.1089346-9-clg@kaod.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: aspeed: Add support for the AST2400 SPI controller

Extend the driver for the AST2400 SPI Flash Controller (SPI). This
controller has a slightly different interface which requires
adaptation of the 4B handling. Summary of features :

. host Firmware
. 1 chip select pin (CE0)
. slightly different register set, between AST2500 and the legacy
controller
. no segment registers
. single, dual mode.

Reviewed-by: Joel Stanley <joel@jms.id.au>
Tested-by: Joel Stanley <joel@jms.id.au>
Tested-by: Tao Ren <rentao.bupt@gmail.com>
Tested-by: Jae Hyun Yoo <quic_jaehyoo@quicinc.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Link: https://lore.kernel.org/r/20220509175616.1089346-8-clg@kaod.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: aspeed: Workaround AST2500 limitations

It is not possible to configure a full 128MB window for a chip of the
same size on the AST2500 SPI controller. For this case, the maximum
window size is restricted to 120MB for CE0.

Reviewed-by: Joel Stanley <joel@jms.id.au>
Tested-by: Joel Stanley <joel@jms.id.au>
Tested-by: Tao Ren <rentao.bupt@gmail.com>
Tested-by: Jae Hyun Yoo <quic_jaehyoo@quicinc.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Link: https://lore.kernel.org/r/20220509175616.1089346-7-clg@kaod.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: aspeed: Adjust direct mapping to device size

The segment registers of the FMC/SPI controllers provide a way to
configure the mapping window of the flash device contents on the AHB
bus. Adjust this window to the size of the spi-mem mapping.

Things get more complex with multiple devices. The driver needs to
also adjust the window of the next device to make sure that there is
no overlap, even if there is no available device. The proposal below
is not perfect but it is covering all the cases we have seen on
different boards with one and two devices on the same bus.

Reviewed-by: Joel Stanley <joel@jms.id.au>
Tested-by: Joel Stanley <joel@jms.id.au>
Tested-by: Tao Ren <rentao.bupt@gmail.com>
Tested-by: Jae Hyun Yoo <quic_jaehyoo@quicinc.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Link: https://lore.kernel.org/r/20220509175616.1089346-6-clg@kaod.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: aspeed: Add support for direct mapping

Use direct mapping to read the flash device contents. This operation
mode is called "Command mode" on Aspeed SoC SMC controllers. It uses a
Control Register for the settings to apply when a memory operation is
performed on the flash device mapping window.

If the window is not big enough, fall back to the "User mode" to
perform the read.

Direct mapping for writes will come later when validated.

Reviewed-by: Joel Stanley <joel@jms.id.au>
Tested-by: Joel Stanley <joel@jms.id.au>
Tested-by: Tao Ren <rentao.bupt@gmail.com>
Tested-by: Jae Hyun Yoo <quic_jaehyoo@quicinc.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Link: https://lore.kernel.org/r/20220509175616.1089346-5-clg@kaod.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-mem: Convert Aspeed SMC driver to spi-mem

This SPI driver adds support for the Aspeed static memory controllers
of the AST2600, AST2500 and AST2400 SoCs using the spi-mem interface.

* AST2600 Firmware SPI Memory Controller (FMC)
. BMC firmware
. 3 chip select pins (CE0 ~ CE2)
. Only supports SPI type flash memory
. different segment register interface
. single, dual and quad mode.

* AST2600 SPI Flash Controller (SPI1 and SPI2)
. host firmware
. 2 chip select pins (CE0 ~ CE1)
. different segment register interface
. single, dual and quad mode.

* AST2500 Firmware SPI Memory Controller (FMC)
. BMC firmware
. 3 chip select pins (CE0 ~ CE2)
. supports SPI type flash memory (CE0-CE1)
. CE2 can be of NOR type flash but this is not supported by the driver
. single, dual mode.

* AST2500 SPI Flash Controller (SPI1 and SPI2)
. host firmware
. 2 chip select pins (CE0 ~ CE1)
. single, dual mode.

* AST2400 New Static Memory Controller (also referred as FMC)
. BMC firmware
. New register set
. 5 chip select pins (CE0 ∼ CE4)
. supports NOR flash, NAND flash and SPI flash memory.
. single, dual and quad mode.

Each controller has a memory range on which flash devices contents are
mapped. Each device is assigned a window that can be changed at bootime
with the Segment Address Registers.

Each SPI flash device can then be accessed in two modes: Command and
User. When in User mode, SPI transfers are initiated with accesses to
the memory segment of a device. When in Command mode, memory
operations on the memory segment of a device generate SPI commands
automatically using a Control Register for the settings.

This initial patch adds support for User mode. Command mode needs a little
more work to check that the memory window on the AHB bus fits the device
size. It will come later when support for direct mapping is added.

Single and dual mode RX transfers are supported. Other types than SPI
are not supported.

Reviewed-by: Joel Stanley <joel@jms.id.au>
Tested-by: Joel Stanley <joel@jms.id.au>
Tested-by: Tao Ren <rentao.bupt@gmail.com>
Tested-by: Jae Hyun Yoo <quic_jaehyoo@quicinc.com>
Signed-off-by: Chin-Ting Kuo <chin-ting_kuo@aspeedtech.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Link: https://lore.kernel.org/r/20220509175616.1089346-4-clg@kaod.org
Signed-off-by: Mark Brown <broonie@kernel.org>