spi: dw: 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/20230728093221.3312026-20-yangyingliang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Add DMA address widths capability check

Store address width capabilities of DMA controller during init and check
the same per transfer to make sure the bits/word requirement can be met.

Current DW DMA driver requires both tx and rx channel to be configured
and functional hence a subset of both tx and rx channel address width
capability is checked with the width requirement(n_bytes) for a
transfer.

* tested on Baikal-T1 based system with DW SPI-looped back interface
transferring a chunk of data with DFS:8,12,16.

Signed-off-by: Joy Chakraborty <joychakr@google.com
Reviewed-by: Serge Semin <fancer.lancer@gmail.com
Tested-by: Serge Semin <fancer.lancer@gmail.com
Link: https://lore.kernel.org/r/20230512104746.1797865-3-joychakr@google.com
Signed-off-by: Mark Brown <broonie@kernel.org

spi: dw: Add support for Intel Thunder Bay SPI controller

Add support for Intel Thunder Bay SPI controller, which uses DesignWare
DWC_ssi core and also add common init function for both Keem Bay and
Thunder Bay.

Signed-off-by: Nandhini Srikandan <nandhini.srikandan@intel.com>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Link: https://lore.kernel.org/r/20220713042223.1458-5-nandhini.srikandan@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Add support for master mode selection for DWC SSI controller

Add support to select the controller mode as master mode by setting Bit 31
of CTRLR0 register. This feature is supported for controller versions above
v1.02.

Signed-off-by: Nandhini Srikandan <nandhini.srikandan@intel.com>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Link: https://lore.kernel.org/r/20220713042223.1458-4-nandhini.srikandan@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Fix IP-core versions macro

Add the missing underscore in IP version macro to avoid compilation issue.
The macro is used for IP version comparison in the current patchset.

Fixes: 2cc8d9227bbb ("spi: dw: Introduce Synopsys IP-core versions interface")
Signed-off-by: Nandhini Srikandan <nandhini.srikandan@intel.com>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Link: https://lore.kernel.org/r/20220713042223.1458-2-nandhini.srikandan@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Define the capabilities in a continuous bit-flags set

Since the DW_SPI_CAP_DWC_HSSI capability has just been replaced with using
the DW SSI IP-core versions interface, the DW SPI capability flags are now
represented with a gap. Let's fix it by redefining the DW_SPI_CAP_DFS32
macro to setting BIT(2) of the capabilities field.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211115181917.7521-8-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Replace DWC_HSSI capability with IP-core version checker

Since there is a common IP-core and component versions interface available
we can use it to differentiate the DW HSSI device features in the code.
Let's remove the corresponding DWC_HSSI capability flag then and use the
dw_spi_ip_is() macro instead.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211115181917.7521-7-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Introduce Synopsys IP-core versions interface

The driver currently supports two IP-core versions. It's DW APB SSI which
is older version of the controller with APB system bus interface, and DW
SSI controller with AHB bus interface. The later one is supposed to be a
new generation high-speed SSI. Even though both of these IP-cores have got
an almost identical registers space there are some differences. The driver
differentiates these distinctions by the DW_SPI_CAP_DWC_HSSI capability
flag. In addition to that each DW SSI IP-core is equipped with a Synopsys
Component version register, which encodes the IP-core release ID the has
been synthesized from. Seeing we are going to need the later one to
differentiate some controller peculiarities it would be better to have a
unified interface for both IP-core line and release versions instead of
using each of them separately.

Introduced here IP-core versioning interface consists of two parts:
1) IDs of the IP-core (virtual) and component versions.
2) a set of macro helpers to identify current IP-core and component
versions.

So the platform code is supposed to assign a proper IP-core version based
on it's platform -knowledge. The main driver initialization method reads
the IP-core release ID from the SSI component version register. That data
is used by the helpers to distinguish one IP-core release from another.
Thus the rest of the driver can use these macros to implement the
conditional code execution based on the specified IP-core and version IDs.

Collect the IP-core versions interface and the defined capabilities at the
top of the header file since they represent a common device description
data and so to immediately available for the driver hackers.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211115181917.7521-6-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Convert to using the Bitfield access macros

The driver has been using the offset/bitwise-shift-based approach for the
CSR fields R/W operations since it was merged into the kernel. It can be
simplified by using the macros defined in the linux/bitfield.h and
linux/bit.h header files like BIT(), GENMASK(), FIELD_PREP(), FIELD_GET(),
etc where it is required, for instance in the cached cr0 preparation
method. Thus in order to have the FIELD_*()-macros utilized we just need
to convert the macros with the CSR-fields offsets to the masks with the
corresponding registers fields definition. That's where the GENMASK() and
BIT() macros come in handy. After that the masks can be used in the
FIELD_*()-macros where it's appropriate.

We also need to convert the macros with the CRS-bit flags using the manual
bitwise shift operations (x << y) to using the BIT() macro. Thus we'll
have a more coherent set of the CSR-related macros.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211115181917.7521-5-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Put the driver entities naming in order

Mostly due to a long driver history it's methods and macro names look a
bit messy. In particularly that concerns the code their prefixes. A
biggest part of the driver functions and macros have got the dw_spi/DW_SPI
prefixes. But there are some entities which have been just
"spi_/SPI_"-prefixed. Especially that concerns the CSR and their fields
macro definitions. It makes the code harder to comprehend since such
methods and macros can be easily confused with the global SPI-subsystem
exports. In this case the only possible way to more or less quickly
distinguish one naming space from another is either by context or by the
argument type, which most of the times isn't that easy anyway. In addition
to that a new DW SSI IP-core support has been added in the framework of
commit e539f435cb9c ("spi: dw: Add support for DesignWare DWC_ssi"), which
introduced a new set or macro-prefixes to describe CTRLR0-specific fields
and worsen the situation. Finally there are methods with
no DW SPI driver-reference prefix at all, that make the code reading even
harder. So in order to ease the driver hacking let's bring the code naming
to a common base:
1) Each method is supposed to have "dw_spi_" prefix so to be easily
distinguished from the kernel API, e.g. SPI-subsystem methods and macros.
(Exception is the local implementation of the readl/writel methods since
being just the regspace accessors.)
2) Each generically used macro should have DW_SPI_-prefix thus being
easily comprehended as the local driver definition.
3) DW APB SSI and DW SSI specific macros should have prefixes as DW_PSSI_
and DW_HSSI_ respectively so referring to the system buses they support
(APB and AHB similarly to the DT clocks naming like pclk, hclk).

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211115181917.7521-4-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Discard redundant DW SSI Frame Formats enumeration

The dw_ssi_type enumeration describes the SPI frame formats the controller
supports, like Motorola SPI, Texas Instruments SSP and National
Semiconductors Microwire, that is the serial protocol utilized for the
SPI-transfers. Depending on the DW SSI IP-core configuration the protocol
could be either fixed or selectable. If it is changebale the protocol can
be selected by means of the CTRL0.FRF field, which possible values encoded
by the dw_ssi_type enumeration. Aside with the denoted enum the field
values are also described by a set of SPI_FRF_{SPI,SSP,MICROWIRE} macros.
Thus currently the DW SPI driver has got two entities describing the same
data. Let's get rid of the enumeration one then, since first it hasn't
been used as enumeration-type but merely as a parametrized values set and
second that would unify the macro-based CSR read/write interface of the
driver. While at it convert the macro names to be more descriptive about
the protocols they represent.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211115181917.7521-3-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Add support for 32-bits max xfer size

The Synopsis DesignWare DW_apb_ssi specifications version 3.23 onward
define a 32-bits maximum transfer size synthesis parameter
(SSI_MAX_XFER_SIZE=32) in addition to the legacy 16-bits configuration
(SSI_MAX_XFER_SIZE=16) for SPI controllers. When SSI_MAX_XFER_SIZE=32,
the layout of the ctrlr0 register changes, moving the data frame format
field from bits [3..0] to bits [16..20], and the RX/TX FIFO word size
can be up to 32-bits.

To support this new format, introduce the DW SPI capability flag
DW_SPI_CAP_DFS32 to indicate that a controller is configured with
SSI_MAX_XFER_SIZE=32. Since SSI_MAX_XFER_SIZE is a controller synthesis
parameter not accessible through a register, the detection of this
parameter value is done in spi_hw_init() by writing and reading the
ctrlr0 register and testing the value of bits [3..0]. These bits are
ignored (unchanged) for SSI_MAX_XFER_SIZE=16, allowing the detection.
If a DFS32 capable SPI controller is detected, the new field dfs_offset
in struct dw_spi is set to SPI_DFS32_OFFSET (16).

dw_spi_update_config() is modified to set the data frame size field at
the correct position is the CTRLR0 register, as indicated by the
dfs_offset field of the dw_spi structure.

The DW_SPI_CAP_DFS32 flag is also unconditionally set for SPI slave
controllers, e.g. controllers that have the DW_SPI_CAP_DWC_SSI
capability flag set. However, for these ssi controllers, the dfs_offset
field is set to 0 as before (as per specifications).

Finally, for any controller with the DW_SPI_CAP_DFS32 capability flag
set, dw_spi_add_host() extends the value of bits_per_word_mask from
16-bits to 32-bits. dw_reader() and dw_writer() are also modified to
handle 32-bits iTX/RX FIFO words.

Suggested-by: Sean Anderson <seanga2@gmail.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Link: https://lore.kernel.org/r/20201206011817.11700-3-damien.lemoal@wdc.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Introduce max mem-ops SPI bus frequency setting

In some circumstances the current implementation of the SPI memory
operations may occasionally fail even though they are executed in the
atomic context. This may happen if the system bus is relatively slow in
comparison to the SPI bus frequency, or there is a concurrent access to
it, which makes the MMIO-operations occasionally stalling before
push-pulling data from the DW APB SPI FIFOs. These two problems we've
discovered on the Baikal-T1 SoC. In order to fix them we have no choice
but to set an artificial limitation on the SPI bus speed.

Note currently this limitation will be only applicable for the memory
operations, since the standard SPI core interface is implemented with an
assumption that there is no problem with the automatic CS toggling.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20201007235511.4935-19-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Add memory operations support

Aside from the synchronous Tx-Rx mode, which has been utilized to create
the normal SPI transfers in the framework of the DW SSI driver, DW SPI
controller supports Tx-only and EEPROM-read modes. The former one just
enables the controller to transmit all the data from the Tx FIFO ignoring
anything retrieved from the MISO lane. The later mode is so called
write-then-read operation: DW SPI controller first pushes out all the data
from the Tx FIFO, after that it'll automatically receive as much data as
has been specified by means of the CTRLR1 register. Both of those modes
can be used to implement the memory operations supported by the SPI-memory
subsystem.

The memory operation implementation is pretty much straightforward, except
a few peculiarities we have had to take into account to make things
working. Since DW SPI controller doesn't provide a way to directly set and
clear the native CS lane level, but instead automatically de-asserts it
when a transfer going on, we have to make sure the Tx FIFO isn't empty
during entire Tx procedure. In addition we also need to read data from the
Rx FIFO as fast as possible to prevent it' overflow with automatically
fetched incoming traffic. The denoted peculiarities get to cause even more
problems if DW SSI controller is equipped with relatively small FIFO and
is connected to a relatively slow system bus (APB) (with respect to the
SPI bus speed). In order to workaround the problems for as much as it's
possible, the memory operation execution procedure collects all the Tx
data into a single buffer and disables the local IRQs to speed the
write-then-optionally-read method up.

Note the provided memory operations are utilized by default only if
a glue driver hasn't provided a custom version of ones and this is not
a DW APB SSI controller with fixed automatic CS toggle functionality.

Co-developed-by: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Signed-off-by: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20201007235511.4935-18-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Add generic DW SSI status-check method

The DW SSI errors handling method can be generically implemented for all
types of the transfers: IRQ, DMA and poll-based ones. It will be a
function which checks the overflow/underflow error flags and resets the
controller if any of them is set. In the framework of this commit we make
use of the new method to detect the errors in the IRQ- and DMA-based SPI
transfer execution procedures.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20201007235511.4935-17-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Move num-of retries parameter to the header file

The parameter will be needed for another wait-done method being added in
the framework of the SPI memory operation modification in a further
commit.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20201007235511.4935-16-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: De-assert chip-select on reset

SPI memory operations implementation will require to have the CS register
cleared before executing the operation in order not to have the
transmission automatically started prior the Tx FIFO is pre-initialized.
Let's clear the register then on explicit controller reset to fulfil the
requirements in case of an error or having the CS left set by a bootloader
or another software.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20201007235511.4935-14-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Refactor data IO procedure

The Tx and Rx data write/read procedure can be significantly simplified by
using Tx/Rx transfer lengths instead of the end pointers. By having the
Tx/Rx data leftover lengths (in the number of transfer words) we can get
rid of all subtraction and division operations utilized here and there in
the tx_max(), rx_max(), dw_writer() and dw_reader() methods. Such
modification will not only give us the more optimized IO procedures, but
will make the data IO methods much more readable than before.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20201007235511.4935-9-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Add DW SPI controller config structure

DW APB SSI controller can be used by the two SPI core interfaces:
traditional SPI transfers and SPI memory operations. The controller needs
to be accordingly configured at runtime when the corresponding operations
are executed. In order to do that for the both interfaces from a single
function we introduce a new data wrapper for the transfer mode, data
width, number of data frames (for the automatic data transfer) and the bus
frequency. It will be used by the update_config() method to tune the DW
APB SSI up.

The update_config() method is made exported to be used not only by the DW
SPI core driver, but by the glue layer drivers too. This will be required
in a coming further commit.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20201007235511.4935-8-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Add DWC SSI capability

Currently DWC SSI core is supported by means of setting up the
core-specific update_cr0() callback. It isn't suitable for multiple
reasons. First of all having exported several methods doing the same thing
but for different chips makes the code harder to maintain. Secondly the
spi-dw-core driver exports the methods, then the spi-dw-mmio driver sets
the private data callback with one of them so to be called by the core
driver again. That makes the code logic too complicated. Thirdly using
callbacks for just updating the CR0 register is problematic, since in case
if the register needed to be updated from different parts of the code,
we'd have to create another callback (for instance the SPI device-specific
parameters don't need to be calculated each time the SPI transfer is
submitted, so it's better to pre-calculate the CR0 data at the SPI-device
setup stage).

So keeping all the above in mind let's discard the update_cr0() callbacks,
define a generic and static dw_spi_update_cr0() method and create the
DW_SPI_CAP_DWC_SSI capability, which when enabled would activate the
alternative CR0 register layout.

While at it add the comments to the code path of the normal DW APB SSI
controller setup to make the dw_spi_update_cr0() method looking coherent.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20201007235511.4935-3-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-dw: Remove extraneous locking

There is no point in having the commit 19b61392c5a8 ("spi: spi-dw: Add
lock protect dw_spi rx/tx to prevent concurrent calls") applied. The
commit author made an assumption that the problem with the rx data
mismatch was due to the lack of the data protection. While most likely it
was caused by the lack of the memory barrier. So having the
commit bfda044533b2 ("spi: dw: use "smp_mb()" to avoid sending spi data
error") applied would be enough to fix the problem.

Indeed the spin unlock operation makes sure each memory operation issued
before the release will be completed before it's completed. In other words
it works as an implicit one way memory barrier. So having both smp_mb()
and the spin_unlock_irqrestore() here is just redundant. One of them would
be enough. It's better to leave the smp_mb() since the Tx/Rx buffers
consistency is provided by the data transfer algorithm implementation:
first we initialize the buffers pointers, then make sure the assignments
are visible by the other CPUs by calling the smp_mb(), only after that
enable the interrupt, which handler uses the buffers.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20200920112914.26501-5-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Add KeemBay Master capability

In a further commit we'll have to get rid of the update_cr0() callback and
define a DW SSI capability instead. Since Keem Bay master/slave
functionality is controller by the CTRL0 register bitfield, we need to
first move the master mode selection into the internal corresponding
update_cr0 method, which would be activated by means of the dedicated
DW_SPI_CAP_KEEMBAY_MST capability setup.

Note this will be also useful if the driver will be ever altered to
support the DW SPI slave interface.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20200920112914.26501-11-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Convert CS-override to DW SPI capabilities

There are several vendor-specific versions of the DW SPI controllers,
each of which may have some peculiarities with respect to the original
IP-core. Seeing it has already caused adding flags and a callback into the
DW SPI private data, let's introduce a generic capabilities interface to
tune the generic DW SPI controller driver up in accordance with the
particular controller specifics. It's done by converting a simple
Alpine-specific CS-override capability into the DW SPI controller
capability activated by setting the DW_SPI_CAP_CS_OVERRIDE flag.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20200920112914.26501-10-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Discard DW SSI chip type storages

Keeping SPI peripheral devices type is pointless since first it hasn't
been functionally utilized by any of the client drivers/code and second it
won't work for Microwire type at the very least. Moreover there is no
point in setting up the type by means of the chip-data in the modern
kernel. The peripheral devices with specific interface type need to be
detected in order to activate the corresponding frame format. It most
likely will require some peripheral device specific DT property or
whatever to find out the interface protocol. So let's remove the serial
interface type fields from the DW APB SSI controller and the SPI
peripheral device private data.

Note we'll preserve the explicit SSI_MOTO_SPI interface type setting up to
signify the only currently supported interface protocol.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20200920112914.26501-9-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Use relaxed IO-methods to access FIFOs

In accordance with [1] the relaxed methods are guaranteed to be ordered
with respect to other accesses from the same CPU thread to the same
peripheral. This is what we need during the data read/write from/to the
controller FIFOs being executed within a single IRQ handler or a kernel
task.

Such optimization shall significantly speed the data reader and writer up.
For instance, the relaxed IO-accessors utilization on Baikal-T1 lets the
driver to support the SPI memory operations with bus frequency three-fold
faster than if normal IO-accessors would be used.

[1] "LINUX KERNEL MEMORY BARRIERS", Documentation/memory-barriers.txt,
Section "KERNEL I/O BARRIER EFFECTS"

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20200920112914.26501-8-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Clear IRQ status on DW SPI controller reset

It turns out the IRQ status isn't cleared after switching the controller
off and getting it back on, which may cause raising false error interrupts
if controller has been unsuccessfully used by, for instance, a bootloader
before the driver is loaded. Let's explicitly clear the interrupts status
in the dedicated controller reset method.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20200920112914.26501-6-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Discard IRQ threshold macro

The macro has been unused since a half of FIFO length was defined to be a
marker of the IRQ. Let's remove it definition.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20200920112914.26501-2-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw-dma: Add one-by-one SG list entries transfer

In case if at least one of the requested DMA engine channels doesn't
support the hardware accelerated SG list entries traverse, the DMA driver
will most likely work that around by performing the IRQ-based SG list
entries resubmission. That might and will cause a problem if the DMA Tx
channel is recharged and re-executed before the Rx DMA channel. Due to
non-deterministic IRQ-handler execution latency the DMA Tx channel will
start pushing data to the SPI bus before the Rx DMA channel is even
reinitialized with the next inbound SG list entry. By doing so the DMA
Tx channel will implicitly start filling the DW APB SSI Rx FIFO up, which
while the DMA Rx channel being recharged and re-executed will eventually
be overflown.

In order to solve the problem we have to feed the DMA engine with SG
list entries one-by-one. It shall keep the DW APB SSI Tx and Rx FIFOs
synchronized and prevent the Rx FIFO overflow. Since in general the SPI
tx_sg and rx_sg lists may have different number of entries of different
lengths (though total length should match) we virtually split the
SG-lists to the set of DMA transfers, which length is a minimum of the
ordered SG-entries lengths.

The solution described above is only executed if a full-duplex SPI
transfer is requested and the DMA engine hasn't provided channels with
hardware accelerated SG list traverse capability to handle both SG
lists at once.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200920112322.24585-12-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Add support for RX sample delay register

This add support for the RX_SAMPLE_DLY register. If enabled in the
Designware IP, it allows tuning of the rx data signal by means of an
internal rx sample fifo.

The register is controlled by the rx-sample-delay-ns DT property,
which is defined per SPI slave as well on controller level.

The controller level rx-sample-delay-ns will apply to all slaves
without the property explicitly defined.

The register is located at offset 0xf0, and if the option is not
enabled in the IP, changing the register will have no effect. The
register will only be written if any slave defines a nonzero value
(after scaling by the clock period).

Signed-off-by: Lars Povlsen <lars.povlsen@microchip.com>
Link: https://lore.kernel.org/r/20200824203010.2033-2-lars.povlsen@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Use regset32 DebugFS method to create regdump file

DebugFS kernel interface provides a dedicated method to create the
registers dump file. Use it instead of creating a generic DebugFS
file with manually written read callback function.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
Cc: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
Link: https://lore.kernel.org/r/20200529131205.31838-16-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Cleanup generic DW DMA code namings

Since from now the former Intel MID platform layer is used as a generic
DW SPI DMA module, let's alter the internal methods naming to be
DMA-related instead of having the "mid_" prefix.

Co-developed-by: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
Co-developed-by: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Signed-off-by: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
Signed-off-by: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
Link: https://lore.kernel.org/r/20200529131205.31838-14-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Move Non-DMA code to the DW PCIe-SPI driver

This is a preparation patch before adding the DW DMA support into the
DW SPI MMIO driver. We need to unpin the Non-DMA-specific code from the
intended to be generic DW APB SSI DMA code. This isn't that hard,
since the most part of the spi-dw-mid.c driver in fact implements a
generic DMA interface for the DW SPI controller driver. The only Intel
MID specifics concern getting the max frequency from the MRST Clock
Control Unit and fetching the DMA controller channels from
corresponding PCIe DMA controller. Since first one is related with the
SPI interface configuration we moved it' implementation into the
DW PCIe-SPI driver module. After that former spi-dw-mid.c file
can be just renamed to be the DW SPI DMA module optionally compiled in to
the DW APB SSI core driver.

Co-developed-by: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
Co-developed-by: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Signed-off-by: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
Signed-off-by: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
Link: https://lore.kernel.org/r/20200529131205.31838-11-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Use DMA max burst to set the request thresholds

Each channel of DMA controller may have a limited length of burst
transaction (number of IO operations performed at ones in a single
DMA client request). This parameter can be used to setup the most
optimal DMA Tx/Rx data level values. In order to avoid the Tx buffer
overrun we can set the DMA Tx level to be of FIFO depth minus the
maximum burst transactions length. To prevent the Rx buffer underflow
the DMA Rx level should be set to the maximum burst transactions length.
This commit setups the DMA channels and the DW SPI DMA Tx/Rx levels
in accordance with these rules.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
Link: https://lore.kernel.org/r/20200529131205.31838-8-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Locally wait for the DMA transfers completion

In general each DMA-based SPI transfer can be split up into two stages:
DMA data transmission/reception and SPI-bus transmission/reception. DMA
asynchronous transactions completion can be tracked by means of the
DMA async Tx-descriptor completion callback. But that callback being
called indicates that the DMA transfer has been finished, it doesn't
mean that SPI data transmission is also done. Moreover in fact it isn't
for at least Tx-only SPI transfers. Upon DMA transfer completion some
data is left in the Tx FIFO and being pushed out by the SPI controller.
So in order to make sure that an SPI transfer is completely pushed to the
SPI-bus, the driver has to wait for both DMA transaction and the SPI-bus
transmission/reception are finished. Note if there is a way to
asynchronously track the former event by means of the DMA async Tx
callback, there isn't easy one for the later (IRQ-based solution won't
work since SPI controller doesn't notify about Rx FIFO being empty).

The DMA transfer completion callback isn't suitable to wait for the
SPI controller activity finish either. The callback might (in case of DW
DMAC it will) be called in the tasklet context. Waiting for the SPI
controller to complete the transfer might take a considerable amount of
time since SPI-bus might be pretty slow. In this case delaying the
execution in the tasklet atomic context might cause significant system
performance drop.

So to speak the best option we've got to solve the problem is to
consequently wait for both stages being finished in the locally
implemented SPI transfer execution procedure even if it costs us of the
local wait-function re-implementation. In this case we don't need to use
the SPI-core transfer-wait functionality, but we'll make sure that
all DMA and SPI-bus transactions are completely finished before the
SPI-core transfer_one callback returns. In this commit we provide an
implementation of the DMA-transfers completion wait functionality.
The DW APB SSI DMA-specific SPI transfer_one function waits for both
Tx and Rx DMA transfers being finished, and only then exits with zero
returned signalling to the SPI core that the SPI transfer is finished.
This implementation is fully equivalent to the currently used
DMA-execution-SPI-core-wait algorithm. The SPI-bus transmission/reception
wait methods will be added in the follow-up commits.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
Cc: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
Link: https://lore.kernel.org/r/20200529131205.31838-4-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Discard dma_width member of the dw_spi structure

This member has exactly the same value as n_bytes of the DW SPI private
data object, it's calculated at the same point of the transfer method,
n_bytes isn't changed during the whole transfer, and they even serve for
the same purpose - keep number of bytes per transfer word, though the
dma_width is used only to calculate the DMA source/destination addresses
width, which n_bytes could be also utilized for. Taking all of these
into account let's replace the dma_width member usage with n_bytes one
and remove the former.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
Cc: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org

Link: https://lore.kernel.org/r/20200522000806.7381-6-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Discard unused void priv pointer

Seeing the "void *priv" member of the dw_spi data structure is unused
let's remove it. The glue-layers can embed the DW APB SSI controller
descriptor into their private data object. MMIO driver for instance
already utilizes that design pattern.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
Cc: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
Link: https://lore.kernel.org/r/20200522000806.7381-5-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Discard static DW DMA slave structures

Having them declared is redundant since each struct dw_dma_chan has
the same structure embedded and the structure from the passed dma_chan
private pointer will be copied there as a result of the next calls
chain:
dma_request_channel() -> find_candidate() -> dma_chan_get() ->
device_alloc_chan_resources() = dwc_alloc_chan_resources() ->
dw_dma_filter().
So just remove the static dw_dma_chan structures and use a locally
declared data instance with dst_id/src_id set to the same values as
the static copies used to have.

Co-developed-by: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
Signed-off-by: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
Co-developed-by: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Signed-off-by: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org

Link: https://lore.kernel.org/r/20200522000806.7381-4-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Get rid of dma_inited flag

This flag is superfluous in all cases where it's being used, i.e.
* ->can_dma() won't be called without dma_inited == 1
* DMA ->exit() callback can rely on txchan and rxchan variables

So, get rid of dma_inited flag.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200507115449.8093-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Add Elkhart Lake PSE DMA support

Elkhart Lake PSE SPI is capable to utilize PSE DMA engine which is described
in ACPI. With help of acpi-dma module the support becomes a generic one.

Thus, add Elkhart Lake PSE DMA support and generic DMA hooks in SPI DesignWare
driver.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200506153025.21441-8-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Propagate struct device pointer to ->dma_init() callback

In some cases, one of which is coming soon, we would like to have
a struct device pointer to request DMA channel. For this purpose
propagate it to ->dma_init() callback in DMA ops.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200506153025.21441-7-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Add 'mfld' suffix to Intel Medfield related routines

In order to prepare driver for the extension to support newer hardware,
add 'mfld' suffix to some related functions.

While here, move DMA parameters assignment under existing #ifdef
CONFIG_SPI_DW_MID_DMA.

There is no functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200506153025.21441-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Downgrade interrupt.h to irqreturn.h where appropriate

spi-dw-mid.c along with spi-dw.h are direct users of irqreturn.h
and nothing else is being used from interrupt.h. So, switch them
to use the former instead of latter one.

While here, move the header under #ifdef CONFIG_SPI_DW_MID_DMA
in spi-dw-mid.c.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200506153025.21441-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Move interrupt.h to spi-dw.h who is user of it

The actual user of interrupt.h is spi-dw.h and not bus drivers.
Move header there.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200506153025.21441-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Add support for DesignWare DWC_ssi

This patch adds initial support for DesignWare DWC_ssi soft IP. DWC_ssi is
the enhanced version of DW_apb_ssi, which is currently supported by this
driver. Their registers are same, but the bit fields of register CTRLR0
are different.

DWC_ssi has additional features compared to DW_apb_ssi. Major enhancements
in DWC_ssi are hyper bus protocol, boot mode support and advanced XIP
support. DWC_ssi is an AHB slave device, whilst DW_apb_ssi is an APB slave
device.

Register offset
DW_ssi DW_apb_ssi
CTRLR0 0x00 0x00
CTRLR1 0x04 0x04
SSIENR 0x08 0x08
MWCR 0x0c 0x0c
SER 0x10 0x10
BAUDR 0x14 0x14
TXFTLR 0x18 0x18
RXFTLR 0x1c 0x1c
TXFLR 0x20 0x20
RXFLR 0x24 0x24
SR 0x28 0x28
IMR 0x2c 0x2c
ISR 0x30 0x30
RISR 0x34 0x34
TXOICR 0x38 0x38
RXOICR 0x3c 0x3c
RXUICR 0x40 0x40
MSTICR 0x44 0x44
ICR 0x48 0x48
DMACR 0x4c 0x4c
DMATDLR 0x50 0x50
DMARDLR 0x54 0x54
IDR 0x58 0x58
SSI_VERSION_ID 0x5c 0x5c
DRx (0 to 35) 0x60+i*0x4 0x60+i*0x4
RX_SAMPLE_DLY 0xf0 0xf0
SPI_CTRLR0 0xf4 0xf4
TXD_DRIVE_EDGE 0xf8 0xf8
XIP_MODE_BITS 0xfc RSVD

Register configuration - CTRLR0
DW_ssi DW_apb_ssi
SPI_HYPERBUS_EN bit[24] NONE
SPI_FRF bit[23:22] bit[22:21]
DFS_32 NONE bit[20:16]
CFS bit[19:16] bit[15:12]
SSTE bit[14] bit[24]
SRL bit[13] bit[11]
SLV_OE bit[12] bit[10]
TMOD bit[11:10] bit[9:8]
SCPOL | SPHA bit[9:8] bit[7:6]
FRF bit[7:6] bit[5:4]
DFS bit[4:0] bit[3:0]

The documents used are
[1] DW_apb_ssi_databook.pdf version 4.01a (2016.10a).
[2] DWC_ssi_databook.pdf version 1.01a.

Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200505130618.554-4-wan.ahmad.zainie.wan.mohamad@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Add update_cr0() callback to update CTRLR0

This patch adds update_cr0() callback, in struct dw_spi.

Existing code that configure register CTRLR0 is moved into a new
function, dw_spi_update_cr0(), and this will be the default.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200505130618.554-3-wan.ahmad.zainie.wan.mohamad@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Fix typo in few registers name

This patch will fix typo in the register name used in the source code,
to be consistent with the register name used in the databook.

Databook: DW_apb_ssi_databook.pdf version 4.01a

Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200505130618.554-2-wan.ahmad.zainie.wan.mohamad@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: remove unused dw_spi_chip handling

The path of code using this struct is unused since there is no more user
of this. Remove code and struct definition.

Signed-off-by: Clement Leger <cleger@kalray.eu>
Link: https://lore.kernel.org/r/20200416110916.22633-1-cleger@kalray.eu
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-dw: Add lock protect dw_spi rx/tx to prevent concurrent calls

dw_spi_irq() and dw_spi_transfer_one concurrent calls.

I find a panic in dw_writer(): txw = *(u8 *)(dws->tx), when dw->tx==null,
dw->len==4, and dw->tx_end==1.

When tpm driver's message overtime dw_spi_irq() and dw_spi_transfer_one
may concurrent visit dw_spi, so I think dw_spi structure lack of protection.

Otherwise dw_spi_transfer_one set dw rx/tx buffer and then open irq,
store dw rx/tx instructions and other cores handle irq load dw rx/tx
instructions may out of order.

[ 1025.321302] Call trace:
...
[ 1025.321319] __crash_kexec+0x98/0x148
[ 1025.321323] panic+0x17c/0x314
[ 1025.321329] die+0x29c/0x2e8
[ 1025.321334] die_kernel_fault+0x68/0x78
[ 1025.321337] __do_kernel_fault+0x90/0xb0
[ 1025.321346] do_page_fault+0x88/0x500
[ 1025.321347] do_translation_fault+0xa8/0xb8
[ 1025.321349] do_mem_abort+0x68/0x118
[ 1025.321351] el1_da+0x20/0x8c
[ 1025.321362] dw_writer+0xc8/0xd0
[ 1025.321364] interrupt_transfer+0x60/0x110
[ 1025.321365] dw_spi_irq+0x48/0x70
...

Signed-off-by: wuxu.wu <wuxu.wu@huawei.com>
Link: https://lore.kernel.org/r/1577849981-31489-1-git-send-email-wuxu.wu@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Drop GPIO header

The DW driver does not use the legacy GPIO header so drop
it from the spi-dw.h include.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20191030073418.23717-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

dw: spi: add support for Amazon's Alpine spi controller

Add support for a new devicetree compatible string called
'amazon,alpine-apb-ssi', which is necessary for the Amazon Alpine spi
controller. 'amazon,alpine-dw-apb-ssi' is used in the dw spi driver if
specified in the devicetree. Otherwise, fall back to driver default
behavior, i.e. original dw IP hw driver behavior.

Signed-off-by: Talel Shenhar <talel@amazon.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: export dw_spi_set_cs

Export dw_spi_set_cs so it can be used from the various IP integration
modules.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: allow providing own set_cs callback

Allow platform specific drivers to provide their own set_cs callback when
the IP integration requires it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Convert to generalized SPI controller API

Convert to generalized SPI controller API introduced by the
commit 8caab75fd2c2 ("spi: Generalize SPI "master" to "controller"").
Inside driver variable name "master" is still used to indicate the driver
is master only.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spi: dw: Make debugfs use bus num and make irq name unique

Instead of using device name it was suggested that bus number was more
appropriate to differentiate debugfs names. Also reduce buffer size to
more realistic 32 bytes instead of 128.

When request_irq is called the bus number may not be assigned. Therefore
the irq name was not unique when dynamic bus number was being used.
As per most of the spi drivers use the device name instead. No other
use of dws->name could be found so it was removed.

Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: fix multiple slaves with different baudrates

Add current master clock to dws struct and compare it against the
requestedtransfer speed. Update clock divider only if necessary.

Signed-off-by: Matthias Seidel <kernel@mseidel.net>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw-mid: constify dw_spi_dma_ops structure

The dw_spi_dma_ops structure is never modified, so declare it as const.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: introduce spi_shutdown_chip()

This helper disables SPI controller and sets clock to 0.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: Allow interface drivers to limit data I/O to word sizes

The commit dd11444327ce ("spi: dw-spi: Convert 16bit accesses to 32bit
accesses") changed all 16bit accesses in the DW_apb_ssi driver to 32bit.
This, unfortunately, breaks data register access on picoXcell, where the
DW IP needs data register accesses to be word accesses (all other
accesses appear to be OK).

This change introduces a new master variable to allow interface drivers
to specify that 16bit data transfer I/O is required. This change also
introduces the ability to set this variable via device tree bindings in
the MMIO interface driver. Both the core and the MMIO interface driver
default to the current 32bit behaviour.

Before this change, on a picoXcell pc3x3:
spi_master spi32766: interrupt_transfer: fifo overrun/underrun
m25p80 spi32766.0: error -5 reading 9f
m25p80: probe of spi32766.0 failed with error -5

After this change:
m25p80 spi32766.0: m25p40 (512 Kbytes)

Fixes: dd11444327ce ("spi: dw-spi: Convert 16bit accesses to 32bit accesses")
Signed-off-by: Michael van der Westhuizen <michael@smart-africa.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw-spi: Convert 16bit accesses to 32bit accesses

Altera's Arria10 SoC interconnect requires a 32-bit write for APB
peripherals. The current spi-dw driver uses 16-bit accesses in
some locations. This patch converts all the 16-bit reads and
writes to 32-bit reads and writes.

Additional Documentation to Support this Change:
The DW_apb_ssi databook states:
"All registers in the DW_apb_ssi are addressed at 32-bit boundaries
to remain consistent with the AHB bus. Where the physical size of
any register is less than 32-bits wide, the upper unused bits of
the 32-bit boundary are reserved. Writing to these bits has no
effect; reading from these bits returns 0." [1]

[1] Section 6.1 of dw_apb_ssi.pdf (version 3.22a)

Request for test with platforms using the DesignWare SPI IP.

Tested On:
Altera CycloneV development kit
Altera Arria10 development kit
Compile tested for build errors on x86_64 (allyesconfigs)

Signed-off-by: Thor Thayer <tthayer@opensource.altera.com>
Reviewed-and-tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw-mid: convert to use dw_dmac instead of intel_mid_dma

intel_mid_dma seems to be unmaintained for a long time. Moreover, the IP block
of DMA itself is the same in both dw_dmac and intel_mid_dma. This patch moves
spi-dw-midpci to use dw_dmac driver.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw-mid: move to use core SPI DMA mappings

SPI core has a comprehensive function set to map and unmap a message when it's
needed. This patch converts driver to use that advantage.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw-mid: clear ongoing DMA transfers on timeout

This patch shuts up any ongoing DMA transfer in case of error.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw-mid: split dma_setup() from dma_transfer()

The patch splits DMA preparatory code to dma_setup() callback. The change also
converts transfer_one() to program DMA whenever the transfer is DMA mapped. The
change is a follow up of the converion to use SPI core transfer_one_message().
Since the DMA mapped transfers can be interleaved with PIO ones the DMA related
configuration should respect that.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: move to SPI core message handling

This patch removes a lot of duplicate code since SPI core provides a nice
message handling.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: make sure SPI controller is enabled

The error handling is partially broken since the controller is disabled on
error and is not re-enabled until condition occurs, i.e. mode (poll, PIO/DMA),
chip (cs_change), or speed (clk_div) is changed. In the result of these changes
we will have a predictable state of the SPi controller independently on how
successfull was a previous transfer.

The patch disables interrupts and re-enables the SPI controller wherever it
needs to be done. Thus most of the time the SPI controller is kept enabled. The
runtime PM, when it will be implemented, must take care of the controller
disabling and re-enabling.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw-mid: split rx and tx callbacks when DMA

Currently driver wouldn't work properly if user asked for simplex transfer. The
patch separates DMA rx and tx callbacks and finishes transfer correctly in any
case.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw-mid: change magic numbers to the constants

Instead of using magic numbers in the code we create a bit map definition of
the DMACR register and use it.

There is no functional change.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw-mid: remove redundant dmac member

Instead of using that member we prefer to use dma_dev which represents actual
struct device of the DMA device.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: remove FSF address

There is no need to keep FSF address in the head of the file. While here, fix
few typos in the header.

There is no functional change.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dw: add support for gpio controlled chip select

Also, use this opportunity to let spi_chip_sel() handle chip-select
deactivation as well.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: dw: migrate to generic queue infrastructure

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: dw: use managed resources

Migrate mmio code and core driver to managed resources to reduce boilerplate
error handling code. Also, handle clk_enable() failure while at it, and drop
unused dw_spi iolen field.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: dw: drop unused struct dw_spi field

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: spi-dw: fix all sparse warnings

The dw_{read,write}[lw] macros produce sparse warnings everytime they
are used. The "read" ones cause:

warning: cast removes address space of expression
warning: incorrect type in argument 1 (different address spaces)
expected void const volatile [noderef] <asn:2>*addr
got unsigned int *<noident>

And the "write" ones:

warning: cast removes address space of expression
warning: incorrect type in argument 2 (different address spaces)
expected void volatile [noderef] <asn:2>*addr
got unsigned int *<noident>

Fix this by removing struct dw_spi_reg and converting all the register
offsets to #defines. Then convert the macros into inlined functions so
that proper type checking can occur.

While here, also fix the three sparse warnings in spi-dw-mid.c due to
the return value of ioremap_nocache being stored in a u32 * not a
void __iomem *.

With these changes the spi-dw* files all build with no sparse warnings.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

spi/dw: Add spi number into spi irq desc

Signed-off-by: ShuoX Liu <shuox.liu@intel.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>