spi: cadence-qspi: report correct number of chip-select

Set the ->num_chipselect field in struct cqspi_st and struct
spi_controller to the current number of chip-select. The value is
dependent on declared flashes in devicetree.

Previously, the num-cs property from devicetree or the maximum value was
being reported.

Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://msgid.link/r/20240209-cdns-qspi-cs-v1-3-a4f9dfed9ab4@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-qspi: set maximum chip-select to 4

Change the maximum chip-select count in cadence-qspi to 4 instead of 16.
The value gets used as default ->num_chipselect when the num-cs DT
property isn't received from devicetree. It also determines the
cqspi->f_pdata array size.

Hardware only supports values up to 4; see cqspi_chipselect() that sets
CS using a one-bit-per-CS 4-bit register field.

Add a static_assert() call as a defensive measure to ensure we stay
under the SPI subsystem limit. It got set to 4 when introduced in
4d8ff6b0991d ("spi: Add multi-cs memories support in SPI core") and
later increased to 16 in 2f8c7c3715f2 ("spi: Raise limit on number of
chip selects").

Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://msgid.link/r/20240209-cdns-qspi-cs-v1-2-a4f9dfed9ab4@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-qspi: assert each subnode flash CS is valid

Check each flash CS against the num-cs property from devicetree.
Fallback to the driver max supported value (CQSPI_MAX_CHIPSELECT) if
num-cs isn't present.

cqspi->num_chipselect is set in cqspi_of_get_pdata() to the num-cs
devicetree property, or to CQSPI_MAX_CHIPSELECT if num-cs is not set.

Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Link: https://msgid.link/r/20240209-cdns-qspi-cs-v1-1-a4f9dfed9ab4@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Follow renaming of SPI "master" to "controller"

In commit 8caab75fd2c2 ("spi: Generalize SPI "master" to "controller"")
some functions and struct members were renamed. To not break all drivers
compatibility macros were provided.

To be able to remove these compatibility macros push the renaming into
this driver.

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/d741960846b7f4896eeff91a4c8c7dfa8a6f8b7b.1707324794.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Don't emit error message on allocation error

Drivers are not supposed to emit an error message when a memory
allocation fails, as the kernel is very loud in this case already
anyhow.

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/8da90785395664bf17d16428f46e84b95ef5cc3b.1707324794.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-qspi: add system-wide suspend and resume callbacks

Each SPI controller is expected to call the spi_controller_suspend() and
spi_controller_resume() callbacks at system-wide suspend and resume.

It (1) handles the kthread worker for queued controllers and (2) marks
the controller as suspended to have spi_sync() fail while the
controller is unavailable.

Those two operations do not require the controller to be active, we do
not need to increment the runtime PM usage counter.

Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://msgid.link/r/20240222-cdns-qspi-pm-fix-v4-4-6b6af8bcbf59@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-qspi: put runtime in runtime PM hooks names

Follow kernel naming convention with regards to power-management
callback function names.

The convention in the kernel is:
- prefix_suspend means the system-wide suspend callback;
- prefix_runtime_suspend means the runtime PM suspend callback.
The same applies to resume callbacks.

Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Link: https://msgid.link/r/20240222-cdns-qspi-pm-fix-v4-3-6b6af8bcbf59@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-qspi: remove system-wide suspend helper calls from runtime PM hooks

The ->runtime_suspend() and ->runtime_resume() callbacks are not
expected to call spi_controller_suspend() and spi_controller_resume().
Remove calls to those in the cadence-qspi driver.

Those helpers have two roles currently:
- They stop/start the queue, including dealing with the kworker.
- They toggle the SPI controller SPI_CONTROLLER_SUSPENDED flag. It
requires acquiring ctlr->bus_lock_mutex.

Step one is irrelevant because cadence-qspi is not queued. Step two
however has two implications:
- A deadlock occurs, because ->runtime_resume() is called in a context
where the lock is already taken (in the ->exec_op() callback, where
the usage count is incremented).
- It would disallow all operations once the device is auto-suspended.

Here is a brief call tree highlighting the mutex deadlock:

spi_mem_exec_op()
...
spi_mem_access_start()
mutex_lock(&ctlr->bus_lock_mutex)

cqspi_exec_mem_op()
pm_runtime_resume_and_get()
cqspi_resume()
spi_controller_resume()
mutex_lock(&ctlr->bus_lock_mutex)
...

spi_mem_access_end()
mutex_unlock(&ctlr->bus_lock_mutex)
...

Fixes: 0578a6dbfe75 ("spi: spi-cadence-quadspi: add runtime pm support")
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://msgid.link/r/20240222-cdns-qspi-pm-fix-v4-2-6b6af8bcbf59@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-qspi: fix pointer reference in runtime PM hooks

dev_get_drvdata() gets used to acquire the pointer to cqspi and the SPI
controller. Neither embed the other; this lead to memory corruption.

On a given platform (Mobileye EyeQ5) the memory corruption is hidden
inside cqspi->f_pdata. Also, this uninitialised memory is used as a
mutex (ctlr->bus_lock_mutex) by spi_controller_suspend().

Fixes: 2087e85bb66e ("spi: cadence-quadspi: fix suspend-resume implementations")
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://msgid.link/r/20240222-cdns-qspi-pm-fix-v4-1-6b6af8bcbf59@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: add missing clk_disable_unprepare() in cqspi_probe()

cqspi_jh7110_clk_init() is called after clk_prepare_enable(cqspi->clk),
if it fails, it should goto label 'probe_reset_failed' to disable
cqspi->clk.

In the error path after calling cqspi_jh7110_clk_init(),
cqspi_jh7110_disable_clk() need be called.

Fixes: 33f1ef6d4eb6 ("spi: cadence-quadspi: Add clock configuration for StarFive JH7110 QSPI")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20231129081147.628004-1-yangyingliang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-cadence-quadspi: Fix missing unwind goto warnings

The following smatch warnings [0] were recently introduced:

drivers/spi/spi-cadence-quadspi.c:1882 cqspi_probe() warn: missing
unwind goto?

Fix these warnings by releasing dma channel and adding a goto fail probe.

[0] https://lore.kernel.org/all/5e21c351-cd08-443e-8509-aecf242a4da9@kadam.mountain/

Fixes: 0578a6dbfe75 ("spi: spi-cadence-quadspi: add runtime pm support")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202309140543.03dMbMM5-lkp@intel.com/
Signed-off-by: Dhruva Gole <d-gole@ti.com>
Link: https://lore.kernel.org/r/20230919074658.41666-1-d-gole@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-cadence-quadspi: add runtime pm support

Add runtime pm support to cadence-qspi driver, this allows the driver to
suspend whenever it's is not actively being used thus reducing active
power consumed by the system.

Also, with the use of devm_pm_runtime_enable we no longer need the
fallback probe_pm_failed that used to pm_runtime_disable

Co-developed-by: Apurva Nandan <a-nandan@ti.com>
Signed-off-by: Apurva Nandan <a-nandan@ti.com>
Signed-off-by: Dhruva Gole <d-gole@ti.com>
Link: https://lore.kernel.org/r/20230829062706.786637-1-d-gole@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: 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/20230807140717.3484180-11-yangyingliang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Add clock configuration for StarFive JH7110 QSPI

Add JH7110's clock initialization code to the driver.

Signed-off-by: William Qiu <william.qiu@starfivetech.com>
Reviewed-by: Hal Feng <hal.feng@starfivetech.com>
Link: https://lore.kernel.org/r/20230804020254.291239-3-william.qiu@starfivetech.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230714174955.4064174-1-robh@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Add missing check for dma_set_mask

Add check for dma_set_mask() and return the error if it fails.

Fixes: 1a6f854f7daa ("spi: cadence-quadspi: Add Xilinx Versal external DMA support")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Link: https://lore.kernel.org/r/20230606093859.27818-1-jiasheng@iscas.ac.cn
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Add compatible for AMD Pensando Elba SoC

The AMD Pensando Elba SoC has the Cadence QSPI controller integrated.

The quirk CQSPI_NEEDS_APB_AHB_HAZARD_WAR is added and if enabled
a dummy readback from the controller is performed to ensure
synchronization.

Signed-off-by: Brad Larson <blarson@amd.com
Link: https://lore.kernel.org/r/20230515181606.65953-8-blarson@amd.com
Signed-off-by: Mark Brown <broonie@kernel.org

spi: cadence-quadspi: use macro DEFINE_SIMPLE_DEV_PM_OPS

Using this macro makes the code more readable.
It also inits the members of dev_pm_ops in the following manner
without us explicitly needing to:

.suspend = cqspi_suspend, \
.resume = cqspi_resume, \
.freeze = cqspi_suspend, \
.thaw = cqspi_resume, \
.poweroff = cqspi_suspend, \
.restore = cqspi_resume

Also get rid of conditional compilation based on CONFIG_PM_SLEEP because
it introduces build issues with certain configs when CQSPI_DEV_PM_OPS is
just NULL.

Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202304191900.2fARFQW9-lkp@intel.com/
Fixes: 140623410536 ("mtd: spi-nor: Add driver for Cadence Quad SPI Flash Controller")
Signed-off-by: Dhruva Gole <d-gole@ti.com>
Link: https://lore.kernel.org/r/20230420054257.925092-1-d-gole@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: fix suspend-resume implementations

The cadence QSPI driver misbehaves after performing a full system suspend
resume:
...
spi-nor spi0.0: resume() failed
...
This results in a flash connected via OSPI interface after system suspend-
resume to be unusable.
fix these suspend and resume functions.

Fixes: 140623410536 ("mtd: spi-nor: Add driver for Cadence Quad SPI Flash Controller")
Signed-off-by: Dhruva Gole <d-gole@ti.com>
Link: https://lore.kernel.org/r/20230417091027.966146-3-d-gole@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Disable the SPI before reconfiguring

Observed random DMA timeout failures while doing back to back
transfers which involves switching the modes from DMA to NON-DMA.
This issue is observed while testing the OSPI+UBIFS file system test case
where rootfs is mounted from OSPI UBIFS partition.
To avoid this issue, disable the SPI before changing the configuration
from external DMA to NON-DMA and vice versa and reenable it after changing
the configuration.
As per the Cadence Octal SPI design specification, it is recommended to
disable the Octal-SPI enable bit before reconfiguring.

Signed-off-by: Sai Krishna Potthuri <sai.krishna.potthuri@amd.com>
Link: https://lore.kernel.org/r/20230320095931.2651714-3-sai.krishna.potthuri@amd.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Update the read timeout based on the length

When performing indirect read via external DMA the timeout for
completion is set equal to the read length instead of fixed timeout value.
For reads larger than 500 bytes, the timeout will continue to be
equal to the read length whereas for a small read like the Read Status
Register command, the timeout would be 1 or 2 milliseconds. This is not
enough to cover the overhead needed in setting up DMA, in that case make
sure the timeout is at least 500ms to allow DMA to finish. This solution
is inline with the timeout used for Direct read via DMA.

Signed-off-by: Sai Krishna Potthuri <sai.krishna.potthuri@amd.com>
Link: https://lore.kernel.org/r/20230320095931.2651714-2-sai.krishna.potthuri@amd.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: cadence-quadspi: 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>
Link: https://lore.kernel.org/r/20230303172041.2103336-16-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Add support for StarFive JH7110 QSPI

Add QSPI reset operation in device probe and add RISCV support to
QUAD SPI Kconfig.

Co-developed-by: Ziv Xu <ziv.xu@starfivetech.com>
Signed-off-by: Ziv Xu <ziv.xu@starfivetech.com>
Signed-off-by: William Qiu <william.qiu@starfivetech.com>
Link: https://lore.kernel.org/r/20230302105221.197421-3-william.qiu@starfivetech.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Fix cancel the indirect read mask

This is to cancel the indirect read transfer process,
so should be use CQSPI_REG_INDIRECTRD_CANCEL_MASK

Signed-off-by: Hongbin Ji <jhb_ee@163.com>
Link: https://lore.kernel.org/r/20230222092128.4237-1-jhb_ee@163.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: use STIG mode for small reads

Fix the issue where some flash chips like cypress S25HS256T return the
value of the same register over and over in DAC mode.

For example in the TI K3-AM62x Processors refer [0] Technical Reference
Manual there is a layer of digital logic in front of the QSPI/OSPI
Drive when used in DAC mode. This is part of the Flash Subsystem (FSS)
which provides access to external Flash devices.

The FSS0_0_SYSCONFIG Register (Offset = 4h) has a BIT Field for
OSPI_32B_DISABLE_MODE which has a Reset value = 0. This means, OSPI 32bit
mode enabled by default.

Thus, by default controller operates in 32 bit mode causing it to always
align all data to 4 bytes from a 4byte aligned address. In some flash
chips like cypress for example if we try to read some regs in DAC mode
then it keeps sending the value of the first register that was requested
and inorder to read the next reg, we have to stop and re-initiate a new
transaction.

This causes wrong register values to be read than what is desired when
registers are read in DAC mode. Hence if the data.nbytes is very less
then prefer STIG mode for such small reads.

[0] https://www.ti.com/lit/ug/spruiv7a/spruiv7a.pdf

Signed-off-by: Dhruva Gole <d-gole@ti.com>
Link: https://lore.kernel.org/r/20230125081023.1573712-5-d-gole@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: setup ADDR Bits in cmd reads

Setup the Addr bit field while issuing register reads in STIG mode. This
is needed for example flashes like cypress define in their transaction
table that to read any register there is 1 cmd byte and a few more address
bytes trailing the cmd byte. Absence of addr bytes will obviously fail
to read correct data from flash register that maybe requested by flash
driver because the controller doesn't even specify which address of the
flash register the read is being requested from.

Signed-off-by: Dhruva Gole <d-gole@ti.com>
Link: https://lore.kernel.org/r/20230125081023.1573712-4-d-gole@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Add flag for direct mode writes

Create new flag inorder to avoid playing with use_direct_mode
flag currently being used throughout the driver.
Disable DAC write if auto polling is disabled or CQSPI_DISABLE_DAC_MODE
is set.

Signed-off-by: Dhruva Gole <d-gole@ti.com>
Link: https://lore.kernel.org/r/20230125081023.1573712-3-d-gole@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Reset CMD_CTRL Reg on cmd r/w completion

If one leaves the CQSPI_REG_CMDCTRL in an unclean state this may cause
issues in future command reads. This issue came to light when some flash
reads in STIG mode were coming back dirty.

Signed-off-by: Dhruva Gole <d-gole@ti.com>
Link: https://lore.kernel.org/r/20230125081023.1573712-2-d-gole@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Add minimum operable clock rate warning to baudrate divisor calculation

This Cadence QSPI IP has a 4-bit clock divisor field
for baud rate division. For example:

0b0000 = /2
0b0001 = /4
0b0010 = /6
...
0b1111 = /32

The maximum divisor is 32
(when div = CQSPI_REG_CONFIG_BAUD_MASK).

If we assume a reference clock of 500MHz and we set
our spi-max-frequency to something low, such as 10 MHz.
The calculated bit field for the divisor ends up being:

DIV_ROUND_UP(500000000/(2*10000000))-1 = 25

25 is 0b11001... which truncates to a divisor field of 0b1001 (or /20).

This is higher than our anticipated max-frequency of 10MHz
(500MHz/20 = 25 MHz). Instead, let's make sure we're always using
the maximum divisor (/32) in this case and give the user a warning about
the rate adjustment.

Signed-off-by: Nathan Barrett-Morrison <nathan.morrison@timesys.com>
Link: https://lore.kernel.org/r/20221128164147.158441-1-nathan.morrison@timesys.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: 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/20220928145852.1882221-2-yangyingliang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Fix PM disable depth imbalance in cqspi_probe

The pm_runtime_enable will increase power disable depth. Thus
a pairing decrement is needed on the error handling path to
keep it balanced according to context.

Fixes:73d5fe0462702 ("spi: cadence-quadspi: Remove spi_master_put() in probe failure path")

Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Link: https://lore.kernel.org/r/20220924121310.78331-2-zhangqilong3@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Disable irqs during indirect reads

On architecture where reading the SRAM is slower than the pace at
controller fills it, with interrupt enabled while reading from
SRAM FIFO causes unwanted interrupt storm to CPU.

The inner "bytes to read" loop never exits and waits for the completion
so it is enough to only enable the watermark interrupt when we
are out of bytes to read, which only happens when we start the
transfer (waiting for the FIFO to fill up initially) if the SRAM
is slow.

So only using read watermark interrupt, as the current implementation
doesn't utilize the SRAM full and indirect complete read interrupt.
And disable all the read interrupts while reading from SRAM.

Signed-off-by: Niravkumar L Rabara <niravkumar.l.rabara@intel.com>
Link: https://lore.kernel.org/r/20220813042616.1372110-1-niravkumar.l.rabara@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Remove spi_master_put() in probe failure path

Currently the spi_master is allocated by devm_spi_alloc_master()
and devres core manages the deallocation, but in probe failure
path spi_master_put() is being handled manually which causes
"refcount underflow use-after-free" warning when probe failure happens
after allocating spi_master.

Trimmed backtrace during failure:

refcount_t: underflow; use-after-free.
pc : refcount_warn_saturate+0xf4/0x144
Call trace:
refcount_warn_saturate
kobject_put
put_device
devm_spi_release_controller
devres_release_all

This commit makes relevant changes to remove spi_master_put() from probe
failure path.

Fixes: 606e5d408184 ("spi: cadence-quadspi: Handle spi_unregister_master() in remove()")

Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Link: https://lore.kernel.org/r/20220601071611.11853-1-vaishnav.a@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Remove spi_master_put() in probe failure path

Currently the spi_master is allocated by devm_spi_alloc_master()
and devres core manages the deallocation, but in probe failure
path spi_master_put() is being handled manually which causes
"refcount underflow use-after-free" warning when probe failure happens
after allocating spi_master.

Trimmed backtrace during failure:

refcount_t: underflow; use-after-free.
pc : refcount_warn_saturate+0xf4/0x144
Call trace:
refcount_warn_saturate
kobject_put
put_device
devm_spi_release_controller
devres_release_all

This commit makes relevant changes to remove spi_master_put() from probe
failure path.

Fixes: 606e5d408184 ("spi: cadence-quadspi: Handle spi_unregister_master() in remove()")

Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Link: https://lore.kernel.org/r/20220601071611.11853-1-vaishnav.a@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Handle spi_unregister_master() in remove()

Currently devres managed removal of the spi_controller happens after
removing the power domain of the host platform_device.While this
does not affect the clean removal of the controller, but affects
graceful removal of the child devices if the child device removal
requires issuing commands over SPI.

Eg. flash device being soft reset to 1S-1S-1S mode before removal
so that on next probe operations in 1S-1S-1S mode is successful.

Failure is seen when `rmmod spi-cadence-quadspi` is performed:

root@j7-evm:~# rmmod spi_cadence_quadspi
[ 49.230996] cadence-qspi 47050000.spi: QSPI is still busy after 500ms timeout.
[ 49.238209] spi-nor spi1.0: operation failed with -110
[ 49.244457] spi-nor spi1.0: Software reset failed: -110

and on subsequent modprobe the OSPI flash probe fails as it
is in 8D-8D-8D mode since the previous soft reset did not happen.

root@j7-evm:~# modprobe spi_cadence_quadspi
[ 73.253536] spi-nor spi0.0: unrecognized JEDEC id bytes: ff ff ff ff ff ff
[ 73.260476] spi-nor: probe of spi0.0 failed with error -2

This commit adds necessary changes to perform spi_unregister_master()
in the host device remove() so that the child devices are gracefully
removed before the power domain is removed.

changes tested on J721E with mt35xu512aba flash.

Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Link: https://lore.kernel.org/r/20220511115516.14894-1-vaishnav.a@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: remove unnecessary (void *) casts

Remove a couple of unnecessary casts to `(void *)` when initializing the
`.data` members in the device ID table.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20220510115141.212779-3-abbotti@mev.co.uk
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Add missing blank line in cqspi_request_mmap_dma()

Fix "WARNING: Missing a blank line after declarations" reported by
checkpatch.pl.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20220510115141.212779-2-abbotti@mev.co.uk
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: fix Direct Access Mode disable for SoCFPGA

The Cadence QSPI compatible string required for the SoCFPGA platform
changed from the default "cdns,qspi-nor" to "intel,socfpga-qspi" with
the introduction of an additional quirk in
commit 98d948eb8331 ("spi: cadence-quadspi: fix write completion support").
However, that change did not preserve the previously used
quirk for this platform. Reinstate the `CQSPI_DISABLE_DAC_MODE` quirk
for the SoCFPGA platform.

Fixes: 98d948eb8331 ("spi: cadence-quadspi: fix write completion support")
Cc: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20220427153446.10113-1-abbotti@mev.co.uk
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-cadence-quadspi: using pm_runtime_resume_and_get instead of pm_runtime_get_sync

Using pm_runtime_resume_and_get() to replace pm_runtime_get_sync and
pm_runtime_put_noidle. This change is just to simplify the code, no
actual functional changes.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn>
Link: https://lore.kernel.org/r/20220414085637.2541805-1-chi.minghao@zte.com.cn
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: allow operations with cmd/addr buswidth >1

With the removal of the incorrect logic of cqspi_set_protocol(), ops with
cmd/addr buswidth >1 are now working correctly.

Tested on a TI AM64x with a Macronix MX25U51245G QSPI flash using 1-4-4
operations.

DTR operations are currently untested, so we leave them disabled for now
(except for the previously allowed 8-8-8 ops).

Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Link: https://lore.kernel.org/r/20220420155616.281730-2-matthias.schiffer@ew.tq-group.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: drop cqspi_set_protocol()

As suggested, this removes the whole cqspi_set_protocol() function, as it
is not actually needed:

- Checks for unsupported operations are already handled by supports_op(),
removing the need to distinguish DTR and non-DTR modes in the buswidth
setup
- supports_op() ensures that the DTR flags match for all relevant parts of
an operation, so op->cmd.dtr can be used instead of copying the flag to
the cqspi_flash_pdata
- The logic in cqspi_set_protocol() is moved to cqspi_calc_rdreg() and
cqspi_write_setup() (with a helper macro CQSPI_OP_WIDTH())

The helper macro checks nbytes instead of buswidth for 0, for consistency
with supports_op() etc.

Suggested-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Link: https://lore.kernel.org/r/20220420155616.281730-1-matthias.schiffer@ew.tq-group.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: fix incorrect supports_op() return value

Since the conversion to spi-mem, the driver advertised support for
various operations that cqspi_set_protocol() was never expected to handle
correctly - in particuar all non-DTR operations with command or address
buswidth > 1. For DTR, all operations except for 8-8-8 would fail, as
cqspi_set_protocol() returns -EINVAL.

In non-DTR mode, this resulted in data corruption for SPI-NOR flashes that
support such operations. As a minimal fix that can be backported to stable
kernels, simply disallow the unsupported operations again to avoid this
issue.

Fixes: a314f6367787 ("mtd: spi-nor: Convert cadence-quadspi to use spi-mem framework")
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Link: https://lore.kernel.org/r/20220406132832.199777-1-matthias.schiffer@ew.tq-group.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: fix protocol setup for non-1-1-X operations

cqspi_set_protocol() only set the data width, but ignored the command
and address width (except for 8-8-8 DTR ops), leading to corruption of
all transfers using 1-X-X or X-X-X ops. Fix by setting the other two
widths as well.

While we're at it, simplify the code a bit by replacing the
CQSPI_INST_TYPE_* constants with ilog2().

Tested on a TI AM64x with a Macronix MX25U51245G QSPI flash with 1-4-4
read and write operations.

Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Link: https://lore.kernel.org/r/20220331110819.133392-1-matthias.schiffer@ew.tq-group.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-mem: Kill the spi_mem_dtr_supports_op() helper

Now that spi_mem_default_supports_op() has access to the static
controller capabilities (relating to memory operations), and now that
these capabilities have been filled by the relevant controllers, there
is no need for a specific helper checking only DTR operations, so let's
just kill spi_mem_dtr_supports_op() and simply use
spi_mem_default_supports_op() instead.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/linux-mtd/20220127091808.1043392-6-miquel.raynal@bootlin.com

spi: cadence-quadspi: Provide a capability structure

This controller has DTR support, so advertize it with a capability now
that the spi-controller structure contains this new field. This will
later be used by the core to discriminate whether an operation is
supported or not, in a more generic way than having different helpers.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/linux-mtd/20220127091808.1043392-4-miquel.raynal@bootlin.com

spi: cadence-quadspi: fix write completion support

Some versions of the Cadence QSPI controller does not have the write
completion register implemented(CQSPI_REG_WR_COMPLETION_CTRL). On the
Intel SoCFPGA platform the CQSPI_REG_WR_COMPLETION_CTRL register is
not configured.

Add a quirk to not write to the CQSPI_REG_WR_COMPLETION_CTRL register.

Fixes: 9cb2ff111712 ("spi: cadence-quadspi: Disable Auto-HW polling)
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/20211108200854.3616121-1-dinguyen@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: fix dma_unmap_single() call

There are separate constants for the dma-mapping API and the dmaengine
API, mixing them up causes a warning in some builds:

In file included from drivers/spi/spi-cadence-quadspi.c:12:
drivers/spi/spi-cadence-quadspi.c: In function 'cqspi_versal_indirect_read_dma':
drivers/spi/spi-cadence-quadspi.c:950:55: error: implicit conversion from 'enum dma_transfer_direction' to 'enum dma_data_direction' [-Werror=enum-conversion]
950 | dma_unmap_single(dev, dma_addr, bytes_to_dma, DMA_DEV_TO_MEM);
| ^~~~~~~~~~~~~~
include/linux/dma-mapping.h:407:70: note: in definition of macro 'dma_unmap_single'
407 | #define dma_unmap_single(d, a, s, r) dma_unmap_single_attrs(d, a, s, r, 0)
| ^

Fixes: 1a6f854f7daa ("spi: cadence-quadspi: Add Xilinx Versal external DMA support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20211013144600.2378037-1-arnd@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Add Xilinx Versal external DMA support

Add support to read the data from the flash using external DMA.
Cadence Octal SPI Flash Controller has optional DMA peripheral interface
to communicate indirect mode of operations with external DMA.
Xilinx Versal OSPI has external DMA enabled, this will automatically
request the external DMA to fetch the data from SRAM. It supports only
reading the data from SRAM (DMA read) and doesn't support writing the
data to SRAM (DMA write).
Xilinx Versal OSPI read the data from the flash device using external DMA
and write the data to the flash device using software triggered
indirect mode.

Signed-off-by: Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xilinx.com>
Link: https://lore.kernel.org/r/1632478031-12242-5-git-send-email-lakshmi.sai.krishna.potthuri@xilinx.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Add OSPI support for Xilinx Versal SoC

Add OSPI support for Xilinx Versal SoCs.
Disable the Direct Access Controller for Xilinx Versal OSPI.
On Xilinx Versal platform, AXI interface need to be selected as Linear
mode (driven from interconnect rather than external DMA) to use
Software triggered 'indirect' mode of operation. This will be achieved
by calling Xilinx firmware API.

Signed-off-by: Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xilinx.com>
Link: https://lore.kernel.org/r/1632478031-12242-4-git-send-email-lakshmi.sai.krishna.potthuri@xilinx.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Fix check condition for DTR ops

buswidth and dtr fields in spi_mem_op are only valid when the
corresponding spi_mem_op phase has a non-zero length. For example,
SPI NAND core doesn't set buswidth when using SPI_MEM_OP_NO_ADDR
phase.

Fix the dtr checks in set_protocol() and suppports_mem_op() to
ignore empty spi_mem_op phases, as checking for dtr field in
empty phase will result in false negatives.

Signed-off-by: Apurva Nandan <a-nandan@ti.com>
Link: https://lore.kernel.org/r/20210716232504.182-3-a-nandan@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Disable Auto-HW polling

cadence-quadspi has a builtin Auto-HW polling funtionality using which
it keep tracks of completion of write operations. When Auto-HW polling
is enabled, it automatically initiates status register read operation,
until the flash clears its busy bit.

cadence-quadspi controller doesn't allow an address phase when
auto-polling the busy bit on the status register. Unlike SPI NOR
flashes, SPI NAND flashes do require the address of status register
when polling the busy bit using the read register operation. As
Auto-HW polling is enabled by default, cadence-quadspi returns a
timeout for every write operation after an indefinite amount of
polling on SPI NAND flashes.

Disable Auto-HW polling completely as the spi-nor core, spinand core,
etc. take care of polling the busy bit on their own.

Signed-off-by: Apurva Nandan <a-nandan@ti.com>
Link: https://lore.kernel.org/r/20210713125743.1540-2-a-nandan@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-cadence-quadspi: Fix division by zero warning

Fix below division by zero warning:
- The reason for dividing by zero is because the dummy bus width is zero,
but if the dummy n bytes is zero, it indicates that there is no data transfer,
so we can just return zero without doing any calculations.

[ 0.795337] Division by zero in kernel.
:
[ 0.834051] [<807fd40c>] (__div0) from [<804e1acc>] (Ldiv0+0x8/0x10)
[ 0.839097] [<805f0710>] (cqspi_exec_mem_op) from [<805edb4c>] (spi_mem_exec_op+0x3b0/0x3f8)

Fixes: 7512eaf54190 ("spi: cadence-quadspi: Fix dummy cycle calculation when buswidth > 1")
Signed-off-by: Yoshitaka Ikeda <ikeda@nskint.co.jp>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/92eea403-9b21-2488-9cc1-664bee760c5e@nskint.co.jp
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-cadence-quadspi: Revert "Fix division by zero warning"

Revert to change to a better code.

This reverts commit 55cef88bbf12f3bfbe5c2379a8868a034707e755.

Signed-off-by: Yoshitaka Ikeda <ikeda@nskint.co.jp>
Link: https://lore.kernel.org/r/bd30bdb4-07c4-f713-5648-01c898d51f1b@nskint.co.jp
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-cadence-quadspi: Fix division by zero warning

Fix below division by zero warning:
- Added an if statement because buswidth can be zero, resulting in division by zero.
- The modified code was based on another driver (atmel-quadspi).

[ 0.795337] Division by zero in kernel.
:
[ 0.834051] [<807fd40c>] (__div0) from [<804e1acc>] (Ldiv0+0x8/0x10)
[ 0.839097] [<805f0710>] (cqspi_exec_mem_op) from [<805edb4c>] (spi_mem_exec_op+0x3b0/0x3f8)

Fixes: 7512eaf54190 ("spi: cadence-quadspi: Fix dummy cycle calculation when buswidth > 1")
Signed-off-by: Yoshitaka Ikeda <ikeda@nskint.co.jp>
Link: https://lore.kernel.org/r/ed989af6-da88-4e0b-9ed8-126db6cad2e4@nskint.co.jp
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Silence shiftTooManyBitsSigned warning

drivers/spi/spi-cadence-quadspi.c:267:18: warning: Shifting signed 32-bit
value by 31 bits is undefined behaviour [shiftTooManyBitsSigned]
return reg & (1 << CQSPI_REG_CONFIG_IDLE_LSB);
^

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jay Fang <f.fangjian@huawei.com>
Link: https://lore.kernel.org/r/1614854872-8694-1-git-send-email-f.fangjian@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: add missing of_node_put

Fix OF node leaks by calling of_node_put in
for_each_available_child_of_node when the cycle returns.

Generated by: scripts/coccinelle/iterators/for_each_child.cocci

Signed-off-by: Junlin Yang <yangjunlin@yulong.com>
Link: https://lore.kernel.org/r/20210215110425.1012-1-angkery@163.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence: set cqspi to the driver_data field of struct device

When initialize cadence qspi controller, it is need to set cqspi
to the driver_data field of struct device, because it will be
used in function cqspi_remove/suspend/resume(). Otherwise, there
will be a crash trace as below when invoking these finctions.

Fixes: 31fb632b5d43 ("spi: Move cadence-quadspi driver to drivers/spi/")
Cc: stable@vger.kernel.org
Signed-off-by: Meng Li <Meng.Li@windriver.com>
Link: https://lore.kernel.org/r/20210311091220.3615-1-Meng.Li@windriver.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Use spi_mem_dtr_supports_op()

Use the newly introduced spi_mem_dtr_supports_op() to check DTR op
support. This means the buswidth check does not need to be replicated.
It also happens to fix a bug where STR ops with a 2-byte opcode would be
reported as supported.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/20210204141218.32229-2-p.yadav@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Add multi-chipselect support for Intel LGM SoC

Add multiple chipselect support for Intel LGM SoCs,
currently QSPI-NOR and QSPI-NAND supported.

Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@linux.intel.com>
Link: https://lore.kernel.org/r/20201124041840.31066-4-vadivel.muruganx.ramuthevar@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Disable the DAC for Intel LGM SoC

On Intel Lightning Mountain(LGM) SoCs QSPI controller do not use
Direct Access Controller(DAC).

This patch adds a quirk to disable the Direct Access Controller
for data transfer instead it uses indirect data transfe

DAC bit resets to 1 so there is no need to explicitly set it.

Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@linux.intel.com>
Link: https://lore.kernel.org/r/20201124041840.31066-3-vadivel.muruganx.ramuthevar@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Add QSPI support for Intel LGM SoC

Add QSPI controller support for Intel LGM SoC.

Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@linux.intel.com>
Link: https://lore.kernel.org/r/20201124041840.31066-2-vadivel.muruganx.ramuthevar@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Fix build warning on 32-bit platforms

The kernel test robot reports the following warning.

drivers/spi/spi-cadence-quadspi.c:966:24: warning: comparison of distinct pointer types ('typeof (len) *' (aka 'unsigned int *') and 'typeof (500UL) *' (aka 'unsigned long *')) [-Wcompare-distinct-pointer-types]
msecs_to_jiffies(max(len, 500UL)))) {
^~~~~~~~~~~~~~~
include/linux/minmax.h:58:19: note: expanded from macro 'max'
#define max(x, y) __careful_cmp(x, y, >)
^~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:42:24: note: expanded from macro '__careful_cmp'
__builtin_choose_expr(__safe_cmp(x, y), \
^~~~~~~~~~~~~~~~
include/linux/minmax.h:32:4: note: expanded from macro '__safe_cmp'
(__typecheck(x, y) && __no_side_effects(x, y))
^~~~~~~~~~~~~~~~~
include/linux/minmax.h:18:28: note: expanded from macro '__typecheck'
(!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~
1 warning generated.

This happens because size_t is unsigned long on 64-bit platforms like
arm64 but it is unsigned int on 32-bit platforms like arm. Omitting the
"UL" would result in a warning on 64-bit platforms. Squash it by type
casting the arguments to size_t using max_t(). This way builds on both
type of platforms can be satisfied. There is no chance of any truncation
since 500 is small enough to fit into both int and long.

Fixes: f453f293979f ("spi: cadence-quadspi: Wait at least 500 ms for direct reads")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/20210108181457.30291-1-p.yadav@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: Fix distinct pointer types warning for ARCH=mips

Fix a new warning report by build for make ARCH=MIPS allmodconfig:

drivers/spi/spi-cadence-quadspi.c: In function 'cqspi_direct_read_execute':
./include/linux/minmax.h:18:28: warning: comparison of distinct pointer types lacks a cast
18 | (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
| ^~
./include/linux/minmax.h:32:4: note: in expansion of macro '__typecheck'
32 | (__typecheck(x, y) && __no_side_effects(x, y))
| ^~~~~~~~~~~
./include/linux/minmax.h:42:24: note: in expansion of macro '__safe_cmp'
42 | __builtin_choose_expr(__safe_cmp(x, y), \
| ^~~~~~~~~~
./include/linux/minmax.h:58:19: note: in expansion of macro '__careful_cmp'
58 | #define max(x, y) __careful_cmp(x, y, >)
| ^~~~~~~~~~~~~
drivers/spi/spi-cadence-quadspi.c:1153:24: note: in expansion of macro 'max'
1153 | msecs_to_jiffies(max(len, 500UL)))) {
| ^~~

"len" is unsigned,however,"500" is unsigned long.

Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Link: https://lore.kernel.org/r/20210107115704.3835282-1-siyanteng@loongson.cn
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Add DTR support

Double Transfer Rate (DTR) mode transfers data twice per clock cycle.
Add support for parsing DTR ops and set up the registers to allow it.

Most SPI NOR flashes expect 2 byte commands. Parse the 2-byte opcode
from SPI MEM and set it up in the CQSPI_REG_OP_EXT_LOWER register.

Increment the delay needed before issuing indirect writes because larger
delay is needed for DTR mode. With the current delay some writes end up
missing.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/20201222184425.7028-8-p.yadav@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Wait at least 500 ms for direct reads

When performing a direct read via DMA the timeout for completion is set
equal to the read length. This is fine for larger reads. For a small
read like the Read Status Register command, the timeout would be 1 or 2
milliseconds. This is not enough to cover the overhead needed in setting
up DMA.

Make sure the timeout is at least 500 ms to allow DMA ample time to
finish. For reads larger than 500 bytes, the timeout will continue to be
equal to the read length.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/20201222184425.7028-7-p.yadav@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Implement a simple supports_op hook

The default SPI MEM supports_op hook rejects DTR ops by default. Add a
simple supports_op hook that very closely imitates the SPI MEM one. It
will be extended in later commits to allow DTR ops.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/20201222184425.7028-6-p.yadav@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Fix dummy cycle calculation when buswidth > 1

SPI MEM deals with dummy bytes but the controller deals with dummy
cycles. Multiplying bytes by 8 is correct if the dummy phase uses 1S
mode since 1 byte will be sent in 8 cycles. But if the dummy phase uses
4S mode then 1 byte will be sent in 2 cycles.

To correctly translate dummy bytes to dummy cycles, the dummy buswidth
also needs to be taken into account. Divide 8 by the buswidth to get the
correct multiplier for getting the number of cycles.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/20201222184425.7028-5-p.yadav@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Set dummy cycles from STIG commands

If a command does not have an address phase it goes via the STIG path.
The dummy cycles are not initialized for the STIG commands. As a result,
STIG commands with dummy cycles will not work.

Initialize the dummy cycle field before issuing the STIG command to make
sure it is sent correctly. Move the code to calculate dummy cycle value
to a separate function so it is not repeated twice. DTR support will add
some more logic here to it is worth it to extract it out in a function.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/20201222184425.7028-4-p.yadav@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Abort read if dummy cycles required are too many

The controller can only support up to 31 dummy cycles. If the command
requires more it falls back to using 31. This command is likely to fail
because the correct number of cycles are not waited upon. Rather than
silently issuing an incorrect command, fail loudly so the caller can get
a chance to find out the command can't be supported by the controller.

Fixes: 140623410536 ("mtd: spi-nor: Add driver for Cadence Quad SPI Flash Controller")
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/20201222184425.7028-3-p.yadav@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Set master max_speed_hz

As of commit 9326e4f1e5dd ("spi: Limit the spi device max speed to
controller's max speed"), the SPI device max speed is set to the
controller's max speed if it is larger. The Cadence QSPI controller does
not set the controller's max speed so it is left at its initial value of
0. This means the SPI device max speed is always set to 0.

The SPI device max speed is used to calculate the baud rate divider when
performing an operation. If this speed is 0, the default divider of 32
is used. No matter what speed is specified by the device tree property
'spi-max-frequency', the device will always operate at ref_clk / 32.

Fix this by setting master->max_speed_hz to the ref clock speed so the
correct divider can be calculated.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/20201222184425.7028-2-p.yadav@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Fix error return code in cqspi_probe

Fix to return the error code from
devm_reset_control_get_optional_exclusive() instaed of 0
in cqspi_probe().

Fixes: 31fb632b5d43ca ("spi: Move cadence-quadspi driver to drivers/spi/")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Link: https://lore.kernel.org/r/20201116141836.2970579-1-chengzhihao1@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: cadence-quadspi: Simplify with dev_err_probe()

Common pattern of handling deferred probe can be simplified with
dev_err_probe(). Less code and the error value gets printed.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200901152713.18629-5-krzk@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-cadence-quadspi: Fix mapping of buffers for DMA reads

Buffers need to mapped to DMA channel's device pointer instead of SPI
controller's device pointer as its system DMA that actually does data
transfer.
Data inconsistencies have been reported when reading from flash
without this fix.

Fixes: ffa639e069fb ("mtd: spi-nor: cadence-quadspi: Add DMA support for direct mode reads")
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Tested-by: Jan Kiszka <jan.kiszka@siemens.com>
Link: https://lore.kernel.org/r/20200831130720.4524-1-vigneshr@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-cadence-quadspi: Populate get_name() interface

Implement get_name() interface of spi_controller_mem_ops so as to avoid
changing of mtd->name due to driver being moved over to spi-mem
framework from SPI NOR. This avoids breaking of MTD cmdline args being
passed by bootloaders which maybe using old driver name.

Fixes: 31fb632b5d43c ("spi: Move cadence-quadspi driver to drivers/spi/")
Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
Suggested-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20200825172506.14375-1-vigneshr@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: Move cadence-quadspi driver to drivers/spi/

Now that cadence-quadspi has been converted to use spi-mem framework,
move it under drivers/spi/

Update license header to match SPI subsystem style

Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@linux.intel.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20200601070444.16923-9-vigneshr@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>