spi: spi-ti-qspi: 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://msgid.link/r/20231128093031.3707034-16-yangyingliang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: Unify error codes by replacing -ENOTSUPP with -EOPNOTSUPP

This commit updates the SPI subsystem, particularly affecting "SPI MEM"
drivers and core parts, by replacing the -ENOTSUPP error code with
-EOPNOTSUPP.

The key motivations for this change are as follows:
1. The spi-nor driver currently uses EOPNOTSUPP, whereas calls to spi-mem
might return ENOTSUPP. This update aims to unify the error reporting
within the SPI subsystem for clarity and consistency.

2. The use of ENOTSUPP has been flagged by checkpatch as inappropriate,
mainly being reserved for NFS-related errors. To align with kernel coding
standards and recommendations, this change is being made.

3. By using EOPNOTSUPP, we provide more specific context to the error,
indicating that a particular operation is not supported. This helps
differentiate from the more generic ENOTSUPP error, allowing drivers to
better handle and respond to different error scenarios.

Risks and Considerations:
While this change is primarily intended as a code cleanup and error code
unification, there is a minor risk of breaking user-space applications
that rely on specific return codes for unsupported operations. However,
this risk is considered low, as such use-cases are unlikely to be common
or critical. Nevertheless, developers and users should be aware of this
change, especially if they have scripts or tools that specifically handle
SPI error codes.

This commit does not introduce any functional changes to the SPI subsystem
or the affected drivers.

Signed-off-by: "Chia-Lin Kao (AceLan)" <acelan.kao@canonical.com>
Acked-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20231129064311.272422-1-acelan.kao@canonical.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: Convert to platform remove callback returning void

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

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

Add an error message to the error path that returned an error before to
replace the core's error message with more information. Apart from the
different wording of the error message, this patch doesn't introduce a
semantic difference.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20231105172649.3738556-2-u.kleine-koenig@pengutronix.de
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: Convert to SPI_CONTROLLER_HALF_DUPLEX

Convert the users under SPI subsystem to SPI_CONTROLLER_HALF_DUPLEX.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230710154932.68377-15-andriy.shevchenko@linux.intel.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: spi-ti-qspi: Support per-transfer and per-slave speed_hz settings

The spi-ti-qspi driver initializes its spi clock by the
spi-max-frequency property from the controller node, and ignores
per-transfer (and per-slave) speed_hz settings.

Isolate clock settings out from ti_qspi_setup() and call it from
ti_qspi_start_transfer_one() and ti_qspi_exec_mem_op(), using
per-transfer speed_hz and per-slave max_speed_hz settings.

Also drop spi_max_frequency from struct ti_qspi and use spi_master's
max_speed_hz.

Signed-off-by: Atsushi Nemoto <atsushi.nemoto@sord.co.jp>
Link: https://lore.kernel.org/r/20220519.084604.966119051165023533.atsushi.nemoto@sord.co.jp
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: using pm_runtime_resume_and_get instead of pm_runtime_get_sync

Using pm_runtime_resume_and_get is more appropriate
for simplifing code

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn>
Link: https://lore.kernel.org/r/20220408080931.2494356-1-chi.minghao@zte.com.cn
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: Fix return value handling of wait_for_completion_timeout

wait_for_completion_timeout() returns unsigned long not int.
It returns 0 if timed out, and positive if completed.
The check for <= 0 is ambiguous and should be == 0 here
indicating timeout which is the only error case.

Fixes: 5720ec0a6d26 ("spi: spi-ti-qspi: Add DMA support for QSPI mmap read")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Link: https://lore.kernel.org/r/20220411111034.24447-1-linmq006@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: Free DMA resources

Release the RX channel and free the dma coherent memory when
devm_spi_register_master() fails.

Fixes: 5720ec0a6d26 ("spi: spi-ti-qspi: Add DMA support for QSPI mmap read")
Cc: stable@vger.kernel.org
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20210218130950.90155-1-tudor.ambarus@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: Free DMA resources

Release the RX channel and free the dma coherent memory when
devm_spi_register_master() fails.

Fixes: 5720ec0a6d26 ("spi: spi-ti-qspi: Add DMA support for QSPI mmap read")
Cc: stable@vger.kernel.org
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20210218130950.90155-1-tudor.ambarus@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: fix reference leak in ti_qspi_setup

pm_runtime_get_sync will increment pm usage counter even it
failed. Forgetting to pm_runtime_put_noidle will result in
reference leak in ti_qspi_setup, so we should fix it.

Fixes: 505a14954e2d7 ("spi/qspi: Add qspi flash controller")
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Link: https://lore.kernel.org/r/20201103140947.3815-1-zhangqilong3@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

SPI SUBSYSTEM: Replace HTTP links with HTTPS ones

Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
If not .svg:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Link: https://lore.kernel.org/r/20200708194400.22213-1-grandmaster@al2klimov.de
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: fix warning

drivers/spi/spi-ti-qspi.c: In function ‘ti_qspi_start_transfer_one’:
drivers/spi/spi-ti-qspi.c:392:8: warning: ‘rx_wlen’ may be used uninitialized in this function [-Wmaybe-uninitialized]
392 | if (rx_wlen >= 32)
| ^
drivers/spi/spi-ti-qspi.c:318:12: note: ‘rx_wlen’ was declared here
318 | u8 rxlen, rx_wlen;
| ^~~~~~~

The warning is a false positive; it is not thrown by all compiler versions, e.g.
Red Hat Cross 9.2.1-1 but not Linaro GCC 7.5-2019.12.

Signed-off-by: Jean Pihet <jean.pihet@newoldbits.com>
Link: https://lore.kernel.org/r/20200115100700.3357-1-jean.pihet@newoldbits.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: optimize byte-transfers

Optimize the 8-bit based transfers, as used by the SPI flash
devices, by reading the data registers by 32 and 128 bits when
possible and copy the contents to the receive buffer.

The speed improvement is 4.9x using quad read.

Signed-off-by: Jean Pihet <jean.pihet@newoldbits.com>
Cc: Ryan Barnett <ryan.barnett@rockwellcollins.com>
Cc: Conrad Ratschan <conrad.ratschan@rockwellcollins.com>
Cc: Arnout Vandecappelle <arnout.vandecappelle@essensium.com>
Link: https://lore.kernel.org/r/20200114124125.361429-3-jean.pihet@newoldbits.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: support large flash devices

The TI QSPI IP has limitations:
- the MMIO region is 64MB in size
- in non-MMIO mode, the transfer can handle 4096 words max.

Add support for bigger devices.
Use MMIO and DMA transfers below the 64MB boundary, use
software generated transfers above.

Signed-off-by: Jean Pihet <jean.pihet@newoldbits.com>
Cc: Ryan Barnett <ryan.barnett@rockwellcollins.com>
Cc: Conrad Ratschan <conrad.ratschan@rockwellcollins.com>
Cc: Arnout Vandecappelle <arnout.vandecappelle@essensium.com>
Link: https://lore.kernel.org/r/20200114124125.361429-2-jean.pihet@newoldbits.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: Remove unused macro for fclk frequency

The fclk and its rate are retrieved from DT.

Signed-off-by: Jean Pihet <jean.pihet@newoldbits.com>
Cc: Ryan Barnett <ryan.barnett@rockwellcollins.com>
Cc: Conrad Ratschan <conrad.ratschan@rockwellcollins.com>
Cc: Arnout Vandecappelle <arnout.vandecappelle@essensium.com>
Link: https://lore.kernel.org/r/20191211193954.747745-2-jean.pihet@newoldbits.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: Fix a bug when accessing non default CS

When switching ChipSelect from default CS0 to any other CS, driver fails
to update the bits in system control module register that control which
CS is mapped for MMIO access. This causes reads to fail when driver
tries to access QSPI flash on CS1/2/3.

Fix this by updating appropriate bits whenever active CS changes.

Reported-by: Andreas Dannenberg <dannenberg@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20191211155216.30212-1-vigneshr@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: Remove dev_err() usage after platform_get_irq()

We don't need dev_err() messages when platform_get_irq() fails now that
platform_get_irq() prints an error message itself when something goes
wrong. Let's remove these prints with a simple semantic patch.

// <smpl>
@@
expression ret;
struct platform_device *E;
@@

ret =
(
platform_get_irq(E, ...)
|
platform_get_irq_byname(E, ...)
);

if ( \( ret < 0 \| ret <= 0 \) )
{
(
-if (ret != -EPROBE_DEFER)
-{ ...
-dev_err(...);
-... }
|
...
-dev_err(...);
)
...
}
// </smpl>

While we're here, remove braces on if statements that only have one
statement (manually).

Cc: Mark Brown <broonie@kernel.org>
Cc: linux-spi@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20190730181557.90391-42-swboyd@chromium.org
Signed-off-by: Mark Brown <broonie@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 296

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gplv2 this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 1 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.986607096@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spi: ti-qspi: Fix mmap read when more than one CS in use

Commit 4dea6c9b0b64 ("spi: spi-ti-qspi: add mmap mode read support") has
has got order of parameter wrong when calling regmap_update_bits() to
select CS for mmap access. Mask and value arguments are interchanged.
Code will work on a system with single slave, but fails when more than
one CS is in use. Fix this by correcting the order of parameters when
calling regmap_update_bits().

Fixes: 4dea6c9b0b64 ("spi: spi-ti-qspi: add mmap mode read support")
Cc: stable@vger.kernel.org
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: ti-qspi: Make sure res_mmap != NULL before dereferencing it

resource_size() is dereferencing the res without checking that it is
not NULL, so we need to do the check before calling resource_size().

Fixes: b95cb394ab59 ("spi: ti-qspi: Implement the spi_mem interface")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: Get rid of the spi_flash_read() API

This API has been replaced by the spi_mem_xx() one, its only user
(spi-nor) has been converted to spi_mem_xx() and all SPI controller
drivers that were implementing the ->spi_flash_xxx() hooks are also
implementing the spi_mem ones. So we can safely get rid of this API.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Frieder Schrempf <frieder.schrempf@exceet.de>
Tested-by: Frieder Schrempf <frieder.schrempf@exceet.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: ti-qspi: Implement the spi_mem interface

The spi_mem interface is meant to replace the spi_flash_read() one.
Implement the ->exec_op() method so that we can smoothly get rid of the
old interface.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Vignesh R <vigneshr@ti.com>
Tested-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: Use bounce buffer if read buffer is not DMA'ble

Flash filesystems like JFFS2, UBIFS and MTD block layer can provide
vmalloc'd or kmap'd buffers that cannot be mapped using dma_map_sg() and
can potentially be in memory region above 32bit addressable region(ie
buffers belonging to memory region backed by LPAE) of DMA, implement
spi_flash_can_dma() interface to inform SPI core not to map such
buffers.
When buffers are not mapped for DMA, then use a pre allocated bounce
buffer(64K = typical flash erase sector size) to read from flash and
then do a copy to actual destination buffer. This is approach is much
faster than using memcpy using CPU and also reduces CPU load.

With this patch, UBIFS read speed is ~18MB/s and CPU utilization <20% on
DRA74 Rev H EVM. Performance degradation is negligible when compared
with non bounce buffer case while using UBIFS.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: Remove unused dma_dev variable

commit 1351aaeb50b2 ("spi: spi-ti-qspi: Use dma_engine wrapper for dma
memcpy call") introduced this warning:

drivers/spi/spi-ti-qspi.c: In function 'ti_qspi_dma_xfer':
drivers/spi/spi-ti-qspi.c:398:21: warning: unused variable 'dma_dev' [-Wunused-variable]
struct dma_device *dma_dev = chan->device;

Fix it by removing the unused variable.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: Use dma_engine wrapper for dma memcpy call

Instead of calling device_prep_dma_memcpy() directly with dma_device
pointer, use the newly introduced dmaengine_prep_dma_memcpy() wrapper
API.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: Fix error handling

'dma_request_chan_by_mask()' can not return NULL.
Try to keep the logic in 'no_dma:' by resetting 'qspi->rx_chan' in case
of error.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: Fix error handling

'dma_request_chan_by_mask()' can not return NULL.
Try to keep the logic in 'no_dma:' by resetting 'qspi->rx_chan' in case
of error.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: ti-qspi: revise ti_qspi_probe() failure flow

call spi_master_put() in case of failures after spi_alloc_master().
call pm_runtime_disable() in case of failures after pm_runtime_enable().

Signed-off-by: Prahlad V <prahlad.eee@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: reinit of completion variable

completion variable should be reinitialized before reusing.

Signed-off-by: Prahlad V <prahlad.eee@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: Add DMA support for QSPI mmap read

Use mem-to-mem DMA to read from flash when reading in mmap mode. This
gives improved read performance and reduces CPU load.

With this patch the raw-read throughput is ~16MB/s on DRA74 EVM. And CPU
load is <20%. UBIFS read throughput ~13 MB/s.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: ti-qspi: spelling mistake: "trasnfers" -> "transfers"

trivial fix to spelling mistake in dev_dbg message

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: Suspend the queue before removing the device

Before disabling the pm_runtime, we must ensure that there is no transfer
in progress nor will a new one be started. Otherwise the message pump will
fail and in the end, the process requesting the transfer will be stuck.
This behavior has been observed when transferring data from a SPI flash
with dd while removing the module on a DRA7x-evm.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: Handle truncated frames properly

We clamp frame_len_words to a maximum of 4096, but do not actually
limit the number of words written or read through the DATA registers
or the length added to spi_message::actual_length. This results in
silent data corruption for commands longer than this maximum.

Recalculate the length of each transfer, taking frame_len_words into
account. Use this length in qspi_{read,write}_msg(), and to increment
spi_message::actual_length.

Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

spi: spi-ti-qspi: Fix FLEN and WLEN settings if bits_per_word is overridden

Each transfer can specify 8, 16 or 32 bits per word independently of
the default for the device being addressed. However, currently we
calculate the number of words in the frame assuming that the word size
is the device default.

If multiple transfers in the same message have differing
bits_per_word, we bitwise-or the different values in the WLEN register
field.

Fix both of these. Also rename 'frame_length' to 'frame_len_words' to
make clear that it's not a byte count like spi_message::frame_length.

Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

spi: spi-ti-qspi: add mmap mode read support

ti-qspi controller provides mmap port to read data from SPI flashes.
mmap port is enabled in QSPI_SPI_SWITCH_REG. ctrl module register may
also need to be accessed for some SoCs. The QSPI_SPI_SETUP_REGx needs to
be populated with flash specific information like read opcode, read
mode(quad, dual, normal), address width and dummy bytes. Once,
controller is in mmap mode, the whole flash memory is available as a
memory region at SoC specific address. This region can be accessed using
normal memcpy() (or mem-to-mem dma copy). The ti-qspi controller hardware
will internally communicate with SPI flash over SPI bus and get the
requested data.

Implement spi_flash_read() callback to support mmap read over SPI
flash devices. With this, the read throughput increases from ~100kB/s to
~2.5 MB/s.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: ti-qspi: improve ->remove() callback

there's no need to call pm_runtime_get_sync()
followed by pm_runtime_put(). We should, instead,
just call pm_runtime_put_sync() and pm_runtime_disable().

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-ti-qspi: switch to polling mode for better r/w performance

Currently word completion interrupt is fired for transfer of every
word(8bit to 128bit in size). This adds a lot of overhead, and decreases
r/w throughput. It hardly takes 3us(@48MHz) for 128bit r/w to complete,
hence its better to poll on word complete bit to be set in
QSPI_SPI_STATUS_REG instead of using interrupts.
This increases the throughput by 30% in both read and write case.

So, switch to polling mode instead of interrupts to determine completion
of word transfer.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: ti-qspi: Fix data corruption seen on r/w stress test

Writing invalid command to QSPI_SPI_CMD_REG will terminate current
transfer and de-assert the chip select. This has to be done before
calling spi_finalize_current_message(). Because
spi_finalize_current_message() will mark the end of current message
transfer and schedule the next transfer. If the chipselect is not
de-asserted before calling spi_finalize_current_message() then the next
transfer will overlap with the previous transfer leading to data
corruption.
__spi_pump_message() can be called either from kthread worker context or
directly from the calling process's context. It is possible that these
two calls can race against each other. But race is serialized by
checking whether master->cur_msg == NULL (pointer to msg being handled
by transfer_one() at present). The master->cur_msg is set to NULL when
spi_finalize_current_message() is called on that message, which means
calling spi_finalize_current_message() allows __spi_sync() to pump next
message in calling process context.
Now if spi-ti-qspi calls spi_finalize_current_message() before we
terminate transfer at hardware side, if __spi_pump_message() is called
from process context then the successive transactions can overlap.

Fix this by moving writing invalid command to QSPI_SPI_CMD_REG to
before calling spi_finalize_current_message() call.

Cc: stable@vger.kernel.org # v3.12+
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: ti-qspi: use 128 bit transfer mode where possible

TI QSPI has four 32 bit data regsiters which can be used to transfer 16
bytes of data at once. The register group QSPI_SPI_DATA_REG_3,
QSPI_SPI_DATA_REG_2, QSPI_SPI_DATA_REG_1 and QSPI_SPI_DATA_REG is
treated as a single 128-bit word for shifting data in and out. The bit
at QSPI_SPI_DATA_REG_3[31] position is the first bit to be shifted out
in case of 128 bit transfer mode. Therefore the first byte to be written
to flash should be at QSPI_SPI_DATA_REG_3[31-25] position.
Instead of writing 1 byte at a time when interacting with spi-nor flash,
make use of all the four registers so that 16 bytes can be transferred
in one go. This reduces number of register writes and Word Complete
interrupts for a given transfer message size, thereby increasing the
write performance.

Without this patch the raw flash write speed is ~100KB/s, with this
patch the write speed increases to ~400 kB/s on DRA74 EVM.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers: spi: ti-qspi: wait for busy bit clear before data write/read

Data corruption is seen while reading/writing large data from/to qspi
device because the data register is over written or read before data
is ready which is denoted by busy bit in status register. SO adding
a busy bit check before writing/reading data to/from qspi device.

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: ti-qspi: cleanup wait_for_completion return handling

return type of wait_for_completion_timeout is unsigned long not int, this
patch uses the return value of wait_for_completion_timeout in the condition
directly rather than assigning it to an incorrect type variable.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: drop owner assignment from platform_drivers

A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

spi/ti-qspi: Fix return from mmap path

mmap resource requirement is only for memory mapped operations.
If the user does not populate mmap resource, dont call return,
instead we go on for normal spi mode operations.

Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: Remove explictly set bus_num and num_chipselect to default setting

The purpose of commit 1e8a52e18cfb
"spi: By default setup spi_masters with 1 chipselect and dynamics bus number"
is to avoid setting default value for bus_num and num_chipselect in spi master
drivers. So let's remove the duplicate code.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-By: David Daney <david.daney@cavium.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: Use SPI_BPW_MASK macro at appropriate places

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

spi: ti-qspi: Fixup driver name

The driver name in current code looks like a compatible string which is not
the naming convention for platform drivers.
Fix it and also add modalias since this driver can be built as a module.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: ti-qspi: Simplify qspi_write_msg and qspi_read_msg implementation

Make the unit of wlen to be byte, and simplify the code to avoid duplicate
code for different wlen cases.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: ti-qspi: Fix getting correct address for qspi

Now platform_get_drvdata() returns the address of qspi rather than master.
Also drop unneeded spi_unregister_master() call in ti_qspi_remove() because
we use devm_spi_register_master() in probe.

commit cbcabb7a300b "spi/qspi: Fix qspi remove path" assumes
platform_get_drvdata() returns address of master. However,
commit 160a061301c7 "spi/qspi: set correct platform drvdata in ti_qspi_probe()"
pass qspi to platform_set_drvdata().

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi/qspi: Fix runtime resume path

Due to the following commit
commit 160a061301c7adf54c40696e7ceedc73f6b747dd
Author: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Date: Mon Nov 11 14:13:41 2013 +0800

spi/qspi: set correct platform drvdata in ti_qspi_probe()

The ti_qspi_remove() use the platform drvdata as a type of
struct ti_qspi, we should pass correct platform drvdata to
platform_set_drvdata() in ti_qspi_probe().

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Mark Brown <broonie@linaro.org>

platform_set_drvdata was changed in the probe, so we need to
correspondingly change deferencing of qspi in runtime resume
path. Else, this will lead to a NULL dereference pointer.

Based on v3.13-rc3

Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi/qspi: parse register by name.

Modify the qspi driver to parse reg information by name.
If "reg names" is not found, then revert back to normal
get resource.

Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi/qspi: Fix qspi remove path.

There is a bug in qspi removal path, as a result of which
qspi cannot be removed when used as a module. The patch
solves the bug and qspi can be removed cleanly.

The bugs fixed are:
-pm_runtime used around register access.
- pm_runtime_disable need to be done before removal.
- spi_unregister_master need to be called to unregister
the spi device.
Tested on DRA7 board.

Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi/qspi: cleanup pm_runtime error check.

clean up pm_runtime error check in accordance with rest of the check in
the driver.

Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi/qspi: set correct platform drvdata in ti_qspi_probe()

The ti_qspi_remove() use the platform drvdata as a type of
struct ti_qspi, we should pass correct platform drvdata to
platform_set_drvdata() in ti_qspi_probe().

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: ti-qspi: one only one interrupt handler

The here used irq and threaded irq handler is a complete non-sense. After
the status register is read and the source disabled it schedules a thread
(the irq thread) to read the status from the variable, invoke complete()
and then renable the interrupt. Again: schedule a thread which invokes
_only_ complete().
This patch removes this non-sense and we remain with one handler which
invokes complete() if needed.
The device remove path should now disable the interupts.
This has been compile time tested.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi/qspi: Add dual/quad read mode bit.

Add dual/quad read mode bit flag for the master controller.
These check will be used in the spi framework to determine
whether the master controller can do dual/quad read respectively.

Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: ti-qspi: use devm_spi_register_master()

Use devm_spi_register_master() to make cleanup paths simpler,
and remove unnecessary remove().

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi/qspi: fix missing unlock on error in ti_qspi_start_transfer_one()

Add the missing unlock before return from function ti_qspi_start_transfer_one()
in the error handling case.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi/qspi: Add compatible string for am4372.

Add a compatible string for am4372.

Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi/qspi: Fix device table entry

Fix module device table entry. Without this, there will
be a build failure while trying to build qspi as a module.

Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi/qspi: Add dual/quad spi read support

Support for multiple lines in SPI framework has been picked[1].
[1]: http://comments.gmane.org/gmane.linux.kernel.spi.devel/14420

Hence, adapting ti qspi driver to support multiple data lines for read.

Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi/qspi: Add qspi flash controller

The patch add basic support for the quad spi controller.

QSPI is a kind of spi module that allows single,
dual and quad read access to external spi devices. The module
has a memory mapped interface which provide direct interface
for accessing data form external spi devices.

The patch will configure controller clocks, device control
register and for defining low level transfer apis which
will be used by the spi framework to transfer data to
the slave spi device(flash in this case).

Test details:
-------------
Tested this on dra7 board.
Test1: Ran mtd_stesstest for 40000 iterations.
- All iterations went through without failure.
Test2: Use mtd utilities:
- flash_erase to erase the flash device
- mtd_debug read to read data back.
- mtd_debug write to write to the data flash.
diff between the write and read data shows zero.

Acked-by: Felipe Balbi<balbi@ti.com>
Reviewed-by: Felipe Balbi<balbi@ti.com>
Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>