A collection of driver specific fixes, there was a bit of a kerfuffle
with some last minute review on hte spi-cadence-quadspi division by zero
change but otherwise nothing terribly remarkable here - important fixes
if you have the hardware but nothing with too wide an impact.
-----BEGIN PGP SIGNATURE-----
iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmD4WjwACgkQJNaLcl1U
h9CofQf/exao6MVAh2aMFv4A0UjQ4jI/wOWzhDY84ooxtTpcSlmAcPNR/yXt7yvc
2s7OcDOSRL8uO9agrnLINDzRrB/+Z8N7ra3sUwzzkNEe6YoOcLYW+GvFSYbyqqPQ
w8Ij6xn05RINQ63WuwwNHNwxlNBcXAT/bkKUkuzAinQi91hehwVQrAgoaNmbDzvI
B0NhSwVEYvlEsfvmVwOJN4VUDbFor31oE3hNvK685ATRvPEQssbQarloK4OsPajv
hOKqDNY/UKggSEFSaeN8gExrylhqEsXk1r+p0S8kKfZnyoNkemPa9xK2QD5YjulE
V9rDs90qjWoA1Rw90e61HvDbtDBgdQ==
=74y9
-----END PGP SIGNATURE-----
Merge tag 'spi-fix-v5.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi
Pull spi fixes from Mark Brown:
"A collection of driver specific fixes, there was a bit of a kerfuffle
with some last minute review on hte spi-cadence-quadspi division by
zero change but otherwise nothing terribly remarkable here - important
fixes if you have the hardware but nothing with too wide an impact"
* tag 'spi-fix-v5.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
spi: spi-bcm2835: Fix deadlock
spi: cadence: Correct initialisation of runtime PM again
spi: cadence-quadspi: Disable Auto-HW polling
spi: spi-cadence-quadspi: Fix division by zero warning
spi: spi-cadence-quadspi: Revert "Fix division by zero warning"
spi: spi-cadence-quadspi: Fix division by zero warning
spi: mediatek: move devm_spi_register_master position
spi: mediatek: fix fifo rx mode
spi: atmel: Fix CS and initialization bug
spi: stm32: fixes pm_runtime calls in probe/remove
spi: imx: mx51-ecspi: Reinstate low-speed CONFIGREG delay
spi: stm32h7: fix full duplex irq handler handling
The driver core ignores the return value of this callback because there
is only little it can do when a device disappears.
This is the final bit of a long lasting cleanup quest where several
buses were converted to also return void from their remove callback.
Additionally some resource leaks were fixed that were caused by drivers
returning an error code in the expectation that the driver won't go
away.
With struct bus_type::remove returning void it's prevented that newly
implemented buses return an ignored error code and so don't anticipate
wrong expectations for driver authors.
Reviewed-by: Tom Rix <trix@redhat.com> (For fpga)
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com> (For drivers/s390 and drivers/vfio)
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> (For ARM, Amba and related parts)
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Chen-Yu Tsai <wens@csie.org> (for sunxi-rsb)
Acked-by: Pali Rohár <pali@kernel.org>
Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org> (for media)
Acked-by: Hans de Goede <hdegoede@redhat.com> (For drivers/platform)
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-By: Vinod Koul <vkoul@kernel.org>
Acked-by: Juergen Gross <jgross@suse.com> (For xen)
Acked-by: Lee Jones <lee.jones@linaro.org> (For mfd)
Acked-by: Johannes Thumshirn <jth@kernel.org> (For mcb)
Acked-by: Johan Hovold <johan@kernel.org>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> (For slimbus)
Acked-by: Kirti Wankhede <kwankhede@nvidia.com> (For vfio)
Acked-by: Maximilian Luz <luzmaximilian@gmail.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> (For ulpi and typec)
Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com> (For ipack)
Acked-by: Geoff Levand <geoff@infradead.org> (For ps3)
Acked-by: Yehezkel Bernat <YehezkelShB@gmail.com> (For thunderbolt)
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> (For intel_th)
Acked-by: Dominik Brodowski <linux@dominikbrodowski.net> (For pcmcia)
Acked-by: Rafael J. Wysocki <rafael@kernel.org> (For ACPI)
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> (rpmsg and apr)
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> (For intel-ish-hid)
Acked-by: Dan Williams <dan.j.williams@intel.com> (For CXL, DAX, and NVDIMM)
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com> (For isa)
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (For firewire)
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> (For hid)
Acked-by: Thorsten Scherer <t.scherer@eckelmann.de> (For siox)
Acked-by: Sven Van Asbroeck <TheSven73@gmail.com> (For anybuss)
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> (For MMC)
Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Finn Thain <fthain@linux-m68k.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210713193522.1770306-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The bcm2835_spi_transfer_one function can create a deadlock
if it is called while another thread already has the
CCF lock.
Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Fixes: f8043872e7 ("spi: add driver for BCM2835")
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210716210245.13240-2-alexandru.tachici@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The security restrictions on the FSI-attached SPI controllers have
been applied universally to all controllers, so the controller can no
longer transfer more than 8 bytes for one transfer. Refactor the driver
to remove the looping and support for larger transfers, and remove the
"restricted" compatible string, as all the controllers are now
considered restricted.
Eddie James (2):
spi: fsi: Reduce max transfer size to 8 bytes
dt-bindings: fsi: Remove ibm,fsi2spi-restricted compatible
.../devicetree/bindings/fsi/ibm,fsi2spi.yaml | 1 -
drivers/spi/spi-fsi.c | 125 +++---------------
2 files changed, 22 insertions(+), 104 deletions(-)
--
2.27.0
For each usage of fifo_words it is clear if ->dynamic_burst is true or
not. This can be used to simplify the function a bit.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Link: https://lore.kernel.org/r/20210716173927.2050620-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
Reuse int_stop_and_reset() in couple of places.
While at it, change the order of the int_stop_and_reset() and pxa2xx_spi_off()
to be in align with the similar flow in int_error_stop().
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210719074842.36060-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The original implementation of RPM handling in probe() was mostly
correct, except it failed to call pm_runtime_get_*() to activate the
hardware. The subsequent fix, 734882a8bf ("spi: cadence: Correct
initialisation of runtime PM"), breaks the implementation further,
to the point where the system using this hard IP on ZynqMP hangs on
boot, because it accesses hardware which is gated off.
Undo 734882a8bf ("spi: cadence: Correct initialisation of runtime
PM") and instead add missing pm_runtime_get_noresume() and move the
RPM disabling all the way to the end of probe(). That makes ZynqMP
not hang on boot yet again.
Fixes: 734882a8bf ("spi: cadence: Correct initialisation of runtime PM")
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Charles Keepax <ckeepax@opensource.cirrus.com>
Cc: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210716182133.218640-1-marex@denx.de
Signed-off-by: Mark Brown <broonie@kernel.org>
cadence-quadspi has a builtin Auto-HW polling funtionality using which
it keep tracks of completion of write operations. When Auto-HW polling
is enabled, it automatically initiates status register read operation,
until the flash clears its busy bit.
cadence-quadspi controller doesn't allow an address phase when
auto-polling the busy bit on the status register. Unlike SPI NOR
flashes, SPI NAND flashes do require the address of status register
when polling the busy bit using the read register operation. As
Auto-HW polling is enabled by default, cadence-quadspi returns a
timeout for every write operation after an indefinite amount of
polling on SPI NAND flashes.
Disable Auto-HW polling completely as the spi-nor core, spinand core,
etc. take care of polling the busy bit on their own.
Signed-off-by: Apurva Nandan <a-nandan@ti.com>
Link: https://lore.kernel.org/r/20210713125743.1540-2-a-nandan@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix below division by zero warning:
- The reason for dividing by zero is because the dummy bus width is zero,
but if the dummy n bytes is zero, it indicates that there is no data transfer,
so we can just return zero without doing any calculations.
[ 0.795337] Division by zero in kernel.
:
[ 0.834051] [<807fd40c>] (__div0) from [<804e1acc>] (Ldiv0+0x8/0x10)
[ 0.839097] [<805f0710>] (cqspi_exec_mem_op) from [<805edb4c>] (spi_mem_exec_op+0x3b0/0x3f8)
Fixes: 7512eaf541 ("spi: cadence-quadspi: Fix dummy cycle calculation when buswidth > 1")
Signed-off-by: Yoshitaka Ikeda <ikeda@nskint.co.jp>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/92eea403-9b21-2488-9cc1-664bee760c5e@nskint.co.jp
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix below division by zero warning:
- Added an if statement because buswidth can be zero, resulting in division by zero.
- The modified code was based on another driver (atmel-quadspi).
[ 0.795337] Division by zero in kernel.
:
[ 0.834051] [<807fd40c>] (__div0) from [<804e1acc>] (Ldiv0+0x8/0x10)
[ 0.839097] [<805f0710>] (cqspi_exec_mem_op) from [<805edb4c>] (spi_mem_exec_op+0x3b0/0x3f8)
Fixes: 7512eaf541 ("spi: cadence-quadspi: Fix dummy cycle calculation when buswidth > 1")
Signed-off-by: Yoshitaka Ikeda <ikeda@nskint.co.jp>
Link: https://lore.kernel.org/r/ed989af6-da88-4e0b-9ed8-126db6cad2e4@nskint.co.jp
Signed-off-by: Mark Brown <broonie@kernel.org>
The comment in setup_fifo_xfer() about setting the watermark wasn't
quite proper grammar and also stopped making sense around commit
6d66507d9b ("spi: spi-geni-qcom: Don't wait to start 1st transfer if
transmitting"). After that commit we actually start the transfer
_before_ the watermark interrupt comes.
I don't think the comment really has any value anymore. We've already
got a comment when we grab the spinlock saying that our interrupt can
come any time as a result of the things in the locked section. Let's
just remove it.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20210712085010.1.Ie3bb9f9d30d6475bb75251d32635194c1c72b9ee@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>
This patch support tick_delay setting, some users need use
high-speed spi speed, which can use tick_delay to tuning spi clk timing.
Signed-off-by: Mason Zhang <Mason.Zhang@mediatek.com>
Link: https://lore.kernel.org/r/20210713114048.29509-1-mason.zhang@mediatek.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This patch move devm_spi_register_master to the end of mtk_spi_probe.
If slaves call spi_sync in there probe function, master should have probe done.
Signed-off-by: Mason Zhang <Mason.Zhang@mediatek.com>
Link: https://lore.kernel.org/r/20210713114247.1536-1-mason.zhang@mediatek.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This series contains fixes & cleanup mainly regarding fifo
and the way end of transfer triggered, when used with or
without DMA.
An additional patch cleans up the pm_runtime calls and another
one enables the autosuspend.
v2: - split pm_runtime fix patch into two
- correct revert commit subject line
Alain Volmat (6):
spi: stm32: fixes pm_runtime calls in probe/remove
spi: stm32: enable pm_runtime autosuspend
spi: stm32h7: fix full duplex irq handler handling
spi: stm32: Revert "properly handle 0 byte transfer"
spi: stm32h7: don't wait for EOT and flush fifo on disable
spi: stm32: finalize message either on dma callback or EOT
Amelie Delaunay (1):
spi: stm32h7: rework rx fifo read function
drivers/spi/spi-stm32.c | 146 +++++++++++++++++-----------------------
1 file changed, 61 insertions(+), 85 deletions(-)
--
2.25.1
This patch add no_need_unprepare support for spi, if spi src clk is
MAIN PLL, it can keep the clk_prepare and will not cause low power
issue. So we no need do clk_prepare/clk_unprepare in runtime pm,
and it will get better performance, because clk_prepare has called
mutex lock.
In the same way,
clk_get_rate also has called mutex lock, so we moved it to spi_probe.
Signed-off-by: Mason Zhang <Mason.Zhang@mediatek.com>
Link: https://lore.kernel.org/r/20210629100814.21402-1-mason.zhang@mediatek.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Depending on the usage, it is necessary to perform the finalize
message operation either upon receiving the EOT interruption,
eiher upon receiving the DMA callback. Indeed, when relying
on DMA, even if the SPI EOT IT has been received, it is
necessary to wait for the end of the DMA RX transaction before
accessing to the data.
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Link: https://lore.kernel.org/r/1625646426-5826-8-git-send-email-alain.volmat@foss.st.com
Signed-off-by: Mark Brown <broonie@kernel.org>
In nominal cases, disable is called as part of the unprepare_message,
after receiving a EOT and after receiving all data so it doesn't
make sense to check for EOT and empty the FIFO.
Moreover, at the end of the disable, the SPI is disable (SPE) leading
to clear of all internal FIFO, leaving the IP in a known status.
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Link: https://lore.kernel.org/r/1625646426-5826-7-git-send-email-alain.volmat@foss.st.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Remove flush parameter and check RXWNE or RXPLVL when end of transfer
flag is set.
Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Link: https://lore.kernel.org/r/1625646426-5826-6-git-send-email-alain.volmat@foss.st.com
Signed-off-by: Mark Brown <broonie@kernel.org>
0 byte transfer handling is now done within the core in code added
by commit b306320322 ("spi: Skip zero-length transfers in spi_transfer_one_message()")
This reverts commit 2269f5a8b1 ("spi: stm32: properly handle 0 byte transfer")
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Link: https://lore.kernel.org/r/1625646426-5826-5-git-send-email-alain.volmat@foss.st.com
Signed-off-by: Mark Brown <broonie@kernel.org>
In FIFO mode were two problems:
- RX mode was never handled and
- in this case the tx_buf pointer was NULL and caused an exception
fix this by handling RX mode in mtk_spi_fifo_transfer
Fixes: a568231f46 ("spi: mediatek: Add spi bus for Mediatek MT8173")
Signed-off-by: Peter Hess <peter.hess@ph-home.de>
Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
Link: https://lore.kernel.org/r/20210706121609.680534-1-linux@fw-web.de
Signed-off-by: Mark Brown <broonie@kernel.org>
Commit 5fa5e6dec7 ("spi: atmel: Switch to transfer_one transfer
method") switched to using transfer_one and set_cs. The
core doesn't call set_cs when the chip select lines are gpios. Add the
SPI_MASTER_GPIO_SS flag to the driver to ensure the calls to set_cs
happen since the driver programs configuration registers there.
Fixes: 5fa5e6dec7 ("spi: atmel: Switch to transfer_one transfer method")
Signed-off-by: Dan Sneddon <dan.sneddon@microchip.com>
Link: https://lore.kernel.org/r/20210629192218.32125-1-dan.sneddon@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Add pm_runtime calls in probe/probe error path and remove
in order to be consistent in all places in ordering and
ensure that pm_runtime is disabled prior to resources used
by the SPI controller.
This patch also fixes the 2 following warnings on driver remove:
WARNING: CPU: 0 PID: 743 at drivers/clk/clk.c:594 clk_core_disable_lock+0x18/0x24
WARNING: CPU: 0 PID: 743 at drivers/clk/clk.c:476 clk_unprepare+0x24/0x2c
Fixes: 038ac869c9 ("spi: stm32: add runtime PM support")
Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Link: https://lore.kernel.org/r/1625646426-5826-2-git-send-email-alain.volmat@foss.st.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Since 00b80ac935 ("spi: imx: mx51-ecspi: Move some initialisation to
prepare_message hook."), the MX51_ECSPI_CONFIG write no longer happens
in prepare_transfer hook, but rather in prepare_message hook, however
the MX51_ECSPI_CONFIG delay is still left in prepare_transfer hook and
thus has no effect. This leads to low bus frequency operation problems
described in 6fd8b8503a ("spi: spi-imx: Fix out-of-order CS/SCLK
operation at low speeds") again.
Move the MX51_ECSPI_CONFIG write delay into the prepare_message hook
as well, thus reinstating the low bus frequency fix.
Fixes: 00b80ac935 ("spi: imx: mx51-ecspi: Move some initialisation to prepare_message hook.")
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210703022300.296114-1-marex@denx.de
Signed-off-by: Mark Brown <broonie@kernel.org>
In case of Full-Duplex mode, DXP flag is set when RXP and TXP flags are
set. But to avoid 2 different handlings, just add TXP and RXP flag in
the mask instead of DXP, and then keep the initial handling of TXP and
RXP events.
Also rephrase comment about EOTIE which is one of the interrupt enable
bits. It is not triggered by any event.
Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Link: https://lore.kernel.org/r/1625042723-661-3-git-send-email-alain.volmat@foss.st.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Some controllers like qcom geni need the parent device to be used for
dma mapping, so add a dma_map_dev field and let drivers fill this to be
used as mapping device
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20210625052213.32260-4-vkoul@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
There is an assignment of ancillary->mode to itself which looks
dubious since the proceeding comment states that the speed and
mode is taken over from the SPI main device, indicating that
ancillary->mode should assigned using the value spi->mode.
Fix this.
Addresses-Coverity: ("Self assignment")
Fixes: 0c79378c01 ("spi: add ancillary device support")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20210623172300.161484-1-colin.king@canonical.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Changes in v10:
- The internal CS inactive function is only supported after VER 0x00110002
Changes in v9:
- Conver to use CS GPIO description
Changes in v8:
- There is a problem with the version 7 mail format. resend it
Changes in v7:
- Fall back "rockchip,rv1126-spi" to "rockchip,rk3066-spi"
Changes in v6:
- Consider to compatibility, the "rockchip,rk3568-spi" is removed in
Series-changes v5, so the commit massage should also remove the
corresponding information
Changes in v5:
- Change to leave one compatible id rv1126, and rk3568 is compatible
with rv1126
Changes in v4:
- Adjust the order patches
- Simply commit massage like redundancy "application" content
Changes in v3:
- Fix compile error which is find by Sascha in [v2,2/8]
Jon Lin (6):
dt-bindings: spi: spi-rockchip: add description for rv1126
spi: rockchip: add compatible string for rv1126
spi: rockchip: Set rx_fifo interrupt waterline base on transfer item
spi: rockchip: Wait for STB status in slave mode tx_xfer
spi: rockchip: Support cs-gpio
spi: rockchip: Support SPI_CS_HIGH
.../devicetree/bindings/spi/spi-rockchip.yaml | 1 +
drivers/spi/spi-rockchip.c | 55 ++++++++++++++-----
2 files changed, 41 insertions(+), 15 deletions(-)
--
2.17.1
dmaengine_terminate_all() is deprecated in favor of explicitly saying if
it should be sync or async. Here, we want dmaengine_terminate_sync()
because there is no other synchronization code in the driver to handle
an async case.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20210623095843.3228-3-wsa+renesas@sang-engineering.com
Signed-off-by: Mark Brown <broonie@kernel.org>
dmaengine_terminate_all() is deprecated in favor of explicitly saying if
it should be sync or async. Here, we want dmaengine_terminate_sync()
because there is no other synchronization code in the driver to handle
an async case.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20210623095843.3228-2-wsa+renesas@sang-engineering.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The current sun6i SPI implementation initializes the transfer too early,
resulting in SCK going high before the transfer. When using an additional
(gpio) chipselect with sun6i, the chipselect is asserted at a time when
clock is high, making the SPI transfer fail.
This is due to SUN6I_GBL_CTL_BUS_ENABLE being written into
SUN6I_GBL_CTL_REG at an early stage. Moving that to the transfer
function, hence, right before the transfer starts, mitigates that
problem.
Fixes: 3558fe900e (spi: sunxi: Add Allwinner A31 SPI controller driver)
Signed-off-by: Mirko Vogt <mirko-dev|linux@nanl.de>
Signed-off-by: Ralf Schlatterbeck <rsc@runtux.com>
Link: https://lore.kernel.org/r/20210614144507.y3udezjfbko7eavv@runtux.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Introduce support for ancillary devices, similar to existing
implementation for I2C. This is useful for devices having
multiple chip-selects, for example some microcontrollers
provide a normal SPI interface and a flashing SPI interface.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20210621175359.126729-2-sebastian.reichel@collabora.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Add OF support as already done for ACPI to take driver
MODULE_DEVICE_TABLE(of, ..) into account.
For example with this change a spi nor device MODALIAS changes from:
MODALIAS=spi:spi-nor
to
MODALIAS=of:Nspi-flashT(null)Cjedec,spi-nor
Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Link: https://lore.kernel.org/r/20210525091003.18228-1-m.felsch@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
In meson_spifc_probe function, when enable the device pclk clock is
error, it should use clk_disable_unprepare to release the core clock.
Signed-off-by: zpershuai <zpershuai@gmail.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/1623562172-22056-1-git-send-email-zpershuai@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix the following make W=1 warning:
drivers/spi/spi-mem.c:819: warning: expecting prototype for spi_mem_driver_unregister_with_owner(). Prototype was for spi_mem_driver_unregister() instead
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20210601120721.3198488-1-yangyingliang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Move the register operation after the clock enable, otherwise system
will stuck when this driver probe.
Fixes: 71d80563b0 ("spi: spi-nxp-fspi: fix fspi panic by unexpected interrupts")
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Link: https://lore.kernel.org/r/1623317073-25158-1-git-send-email-haibo.chen@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>
No one seems to be using this global and exported function, so remove it
as it is no longer needed.
Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20210609071918.2852069-1-gregkh@linuxfoundation.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Commit 4782c0a5dd ("clk: tegra: Don't deassert reset on enabling
clocks") removed some legacy code for handling resets on Tegra from
within the Tegra clock code. This exposed an issue in the Tegra20 slink
driver where the SPI controller reset was not being deasserted as needed
during probe. This is causing the Tegra30 Cardhu platform to hang on
boot. Fix this by ensuring the SPI controller reset is deasserted during
probe.
Fixes: 4782c0a5dd ("clk: tegra: Don't deassert reset on enabling clocks")
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20210608071518.93037-1-jonathanh@nvidia.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This patch uses debugfs_regset32 interface to create the registers dump
file. Use it instead of creating a generic debugfs file with manually
written read callback function.
With these entries, users can check all the SPI controller registers
during run time.
Signed-off-by: Jay Fang <f.fangjian@huawei.com>
Link: https://lore.kernel.org/r/1622789718-13977-1-git-send-email-f.fangjian@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix the following compilation warning using W=1 build:
arm-linux-gnueabi-ld: drivers/spi/spi-stm32-qspi.o: in function `stm32_qspi_poll_status':
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Link: https://lore.kernel.org/r/20210604075009.25914-1-patrice.chotard@foss.st.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Patrice Chotard <patrice.chotard@foss.st.com>:
From: Patrice Chotard <patrice.chotard@foss.st.com>
This series adds support for the spi_mem_poll_status() spinand
interface.
Some QSPI controllers allows to poll automatically memory
status during operations (erase, read or write). This allows to
offload the CPU for this task.
STM32 QSPI is supporting this feature, driver update are also
part of this series.
Changes in v5:
- Update spi_mem_read_status() description.
- Update poll_status() description API by indicating that data buffer is
filled with last status value.
- Update timeout parameter by timeout_ms in spi_mem_poll_status() prototype.
- Remove parenthesys arount -EINVAL in spi_mem_poll_status().
- Add missing spi_mem_supports_op() call in stm32_qspi_poll_status().
- Add Boris Reviewed-by for patch 1 and 2.
Changes in v4:
- Remove init_completion() from spi_mem_probe() added in v2.
- Add missing static for spi_mem_read_status().
- Check if operation in spi_mem_poll_status() is a READ.
- Update patch 2 commit message.
- Add comment which explains how delays has been calculated.
- Rename SPINAND_STATUS_TIMEOUT_MS to SPINAND_WAITRDY_TIMEOUT_MS.
Chnages in v3:
- Add spi_mem_read_status() which allows to read 8 or 16 bits status.
- Add initial_delay_us and polling_delay_us parameters to spi_mem_poll_status().
and also to poll_status() callback.
- Move spi_mem_supports_op() in SW-based polling case.
- Add delay before invoquing read_poll_timeout().
- Remove the reinit/wait_for_completion() added in v2.
- Add initial_delay_us and polling_delay_us parameters to spinand_wait().
- Add SPINAND_READ/WRITE/ERASE/RESET_INITIAL_DELAY_US and
SPINAND_READ/WRITE/ERASE/RESET_POLL_DELAY_US defines.
- Remove spi_mem_finalize_op() API added in v2.
Changes in v2:
- Indicates the spi_mem_poll_status() timeout unit
- Use 2-byte wide status register
- Add spi_mem_supports_op() call in spi_mem_poll_status()
- Add completion management in spi_mem_poll_status()
- Add offload/non-offload case management in spi_mem_poll_status()
- Optimize the non-offload case by using read_poll_timeout()
- mask and match stm32_qspi_poll_status()'s parameters are 2-byte wide
- Make usage of new spi_mem_finalize_op() API in
stm32_qspi_wait_poll_status()
Patrice Chotard (3):
spi: spi-mem: add automatic poll status functions
mtd: spinand: use the spi-mem poll status APIs
spi: stm32-qspi: add automatic poll status feature
drivers/mtd/nand/spi/core.c | 45 +++++++++++++------
drivers/spi/spi-mem.c | 86 ++++++++++++++++++++++++++++++++++++
drivers/spi/spi-stm32-qspi.c | 86 ++++++++++++++++++++++++++++++++----
include/linux/mtd/spinand.h | 22 +++++++++
include/linux/spi/spi-mem.h | 16 +++++++
5 files changed, 234 insertions(+), 21 deletions(-)
base-commit: 6efb943b86
--
2.17.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.orghttp://lists.infradead.org/mailman/listinfo/linux-arm-kernel
The current implementation of the driver holds a spin lock for the
duration of the transfer, releasing it only to enable interrupts for
short periods of time. As this would prevent any interrupt from
happening, this could cause system performance issues every time a SPI
message is sent. Since the spi core now handles message syncronization
we can reduce the amount of time the spin-lock is held to the regions
where both the calling thread and the interrupt might interract.
Signed-off-by: Dan Sneddon <dan.sneddon@microchip.com>
Link: https://lore.kernel.org/r/20210602160816.4890-2-dan.sneddon@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>
STM32 QSPI is able to automatically poll a specified register inside the
memory and relieve the CPU from this task.
As example, when erasing a large memory area, we got cpu load
equal to 50%. This patch allows to perform the same operation
with a cpu load around 2%.
Signed-off-by: Christophe Kerello <christophe.kerello@foss.st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Link: https://lore.kernel.org/r/20210518162754.15940-4-patrice.chotard@foss.st.com
Signed-off-by: Mark Brown <broonie@kernel.org>
With STM32 QSPI, it is possible to poll the status register of the device.
This could be done to offload the CPU during an operation (erase or
program a SPI NAND for example).
spi_mem_poll_status API has been added to handle this feature.
This new function take care of the offload/non-offload cases.
For the non-offload case, use read_poll_timeout() to poll the status in
order to release CPU during this phase.
For example, previously, when erasing large area, in non-offload case,
CPU load can reach ~50%, now it decrease to ~35%.
Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Signed-off-by: Christophe Kerello <christophe.kerello@foss.st.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/r/20210518162754.15940-2-patrice.chotard@foss.st.com
Signed-off-by: Mark Brown <broonie@kernel.org>
In U-boot side, an issue has been encountered when QSPI source clock is
running at low frequency (24 MHz for example), waiting for TCF bit to be
set didn't ensure that all data has been send out the FIFO, we should also
wait that BUSY bit is cleared.
To prevent similar issue in kernel driver, we implement similar behavior
by always waiting BUSY bit to be cleared.
Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Link: https://lore.kernel.org/r/20210603073421.8441-1-patrice.chotard@foss.st.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Since commit 571e31fa60 ("spi: bcm2835: Cache CS register value for
->prepare_message()"), the number of slaves has been limited by a
compile-time constant. This was necessitated by statically-sized
arrays in the driver private data which contain per-slave register
values.
As suggested by Mark, move those register values to a per-slave
controller_state which is allocated on ->setup and freed on ->cleanup.
The limitation on the number of slaves is thus lifted.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: Joe Burmeister <joe.burmeister@devtank.co.uk>
Cc: Phil Elwell <phil@raspberrypi.com>
Link: https://lore.kernel.org/r/a847c01f09400801e74e0630bf5a0197591554da.1622150204.git.lukas@wunner.de
Signed-off-by: Mark Brown <broonie@kernel.org>
In zynq_qspi_probe function, when enable the device clock is done,
the return of all the functions should goto the clk_dis_all label.
If num_cs is not right then this should return a negative error
code but currently it returns success.
Signed-off-by: zpershuai <zpershuai@gmail.com>
Link: https://lore.kernel.org/r/1622110857-21812-1-git-send-email-zpershuai@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Commit c7299fea67 ("spi: Fix spi device unregister flow") changed the
SPI core's behavior if the ->setup() hook returns an error upon adding
an spi_device: Before, the ->cleanup() hook was invoked to free any
allocations that were made by ->setup(). With the commit, that's no
longer the case, so the ->setup() hook is expected to free the
allocations itself.
I've identified 5 drivers which depend on the old behavior and am fixing
them up hereinafter: spi-bitbang.c spi-fsl-spi.c spi-omap-uwire.c
spi-omap2-mcspi.c spi-pxa2xx.c
Importantly, ->setup() is not only invoked on spi_device *addition*:
It may subsequently be called to *change* SPI parameters. If changing
these SPI parameters fails, freeing memory allocations would be wrong.
That should only be done if the spi_device is finally destroyed.
I am therefore using a bool "initial_setup" in 4 of the affected drivers
to differentiate between the invocation on *adding* the spi_device and
any subsequent invocations: spi-bitbang.c spi-fsl-spi.c spi-omap-uwire.c
spi-omap2-mcspi.c
In spi-pxa2xx.c, it seems the ->setup() hook can only fail on spi_device
addition, not any subsequent calls. It therefore doesn't need the bool.
It's worth noting that 5 other drivers already perform a cleanup if the
->setup() hook fails. Before c7299fea67, they caused a double-free
if ->setup() failed on spi_device addition. Since the commit, they're
fine. These drivers are: spi-mpc512x-psc.c spi-pl022.c spi-s3c64xx.c
spi-st-ssc4.c spi-tegra114.c
(spi-pxa2xx.c also already performs a cleanup, but only in one of
several error paths.)
Fixes: c7299fea67 ("spi: Fix spi device unregister flow")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: Saravana Kannan <saravanak@google.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> # pxa2xx
Link: https://lore.kernel.org/r/f76a0599469f265b69c371538794101fa37b5536.1622149321.git.lukas@wunner.de
Signed-off-by: Mark Brown <broonie@kernel.org>
It is helpful to see what state of CS signal was during one
or another SPI operation. All the same for SPI setup.
Enable tracing of the SPI setup and CS selection.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Message-Id: <20210526195655.75691-1-andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
All chipsets from AR7100 up to QCA9563 have three dedicated chipselect
lines for the integrated SPI controller. Set the number of chipselect
lines available on the controller to this value.
Signed-off-by: David Bauer <mail@david-bauer.net>
Link: https://lore.kernel.org/r/20210522074453.39299-2-mail@david-bauer.net
Signed-off-by: Mark Brown <broonie@kernel.org>
The ath79 platform has been converted to pure OF. The platform data is
not needed anymore because of this.
Signed-off-by: David Bauer <mail@david-bauer.net>
Link: https://lore.kernel.org/r/20210522074453.39299-1-mail@david-bauer.net
Signed-off-by: Mark Brown <broonie@kernel.org>
Commit 571e31fa60 ("spi: bcm2835: Cache CS register value for
->prepare_message()") limited the number of slaves to 3 at compile-time.
The limitation was necessitated by a statically-sized array prepare_cs[]
in the driver private data which contains a per-slave register value.
The commit sought to enforce the limitation at run-time by setting the
controller's num_chipselect to 3: Slaves with a higher chipselect are
rejected by spi_add_device().
However the commit neglected that num_chipselect only limits the number
of *native* chipselects. If GPIO chipselects are specified in the
device tree for more than 3 slaves, num_chipselect is silently raised by
of_spi_get_gpio_numbers() and the result are out-of-bounds accesses to
the statically-sized array prepare_cs[].
As a bandaid fix which is backportable to stable, raise the number of
allowed slaves to 24 (which "ought to be enough for anybody"), enforce
the limitation on slave ->setup and revert num_chipselect to 3 (which is
the number of native chipselects supported by the controller).
An upcoming for-next commit will allow an arbitrary number of slaves.
Fixes: 571e31fa60 ("spi: bcm2835: Cache CS register value for ->prepare_message()")
Reported-by: Joe Burmeister <joe.burmeister@devtank.co.uk>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org # v5.4+
Cc: Phil Elwell <phil@raspberrypi.com>
Link: https://lore.kernel.org/r/75854affc1923309fde05e47494263bde73e5592.1621703210.git.lukas@wunner.de
Signed-off-by: Mark Brown <broonie@kernel.org>
Allow SPI peripherals attached to this controller to know what is the
maximum transfer size and message size, so they can limit their transfer
lengths properly in case they are otherwise capable of larger transfer
sizes. For the sc18is602, this is 200 bytes in both cases, since as far
as I understand, it isn't possible to tell the controller to keep the
chip select asserted after the STOP command is sent.
The controller can support SPI messages larger than 200 bytes if
cs_change is set for individual transfers such that the portions with
chip select asserted are never longer than 200 bytes. What is not
supported is just SPI messages with a continuous chip select larger than
200. I don't think it is possible to express this using the current API,
so drivers which do send SPI messages with cs_change can safely just
look at the max_transfer_size limit.
An example of user for this is sja1105_xfer() in
drivers/net/dsa/sja1105/sja1105_spi.c which sends by default 64 * 4 =
256 byte transfers.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20210520131238.2903024-3-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
For each spi_message, the sc18is602 I2C-to-SPI bridge driver checks the
length of each spi_transfer against 200 (the size of the chip's internal
buffer) minus hw->tlen (the number of bytes transferred so far).
The first byte of the transferred data is the Function ID (the SPI
slave's chip select) and as per the documentation of the chip:
https://www.nxp.com/docs/en/data-sheet/SC18IS602B.pdf
the data buffer is up to 200 bytes deep _without_ accounting for the
Function ID byte.
However, in sc18is602_txrx(), the driver keeps the Function ID as part
of the buffer, and increments hw->tlen from 0 to 1. Combined with the
check in sc18is602_check_transfer, this prevents us from issuing a
transfer that has exactly 200 bytes in size, but only 199.
Adjust the check function to reflect that the Function ID is not part of
the 200 byte deep data buffer.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20210520131238.2903024-2-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix missing parenthesis of sizeof reported by checkpatch.pl:
WARNING: sizeof *pp should be sizeof(*pp).
The kernel coding style suggests thinking of sizeof as a function
and add parenthesis.
Signed-off-by: Zhiqi Song <songzhiqi1@huawei.com>
Link: https://lore.kernel.org/r/1621301902-64158-8-git-send-email-songzhiqi1@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix missing parenthesis of sizeof reported by checkpatch.pl:
WARNING: sizeof *pp should be sizeof(*pp).
The kernel coding style suggests thinking of sizeof as a function
and add parenthesis.
Signed-off-by: Zhiqi Song <songzhiqi1@huawei.com>
Link: https://lore.kernel.org/r/1621301902-64158-7-git-send-email-songzhiqi1@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix missing parenthesis of sizeof reported by checkpatch.pl:
WARNING: sizeof *pp should be sizeof(*pp).
The kernel coding style suggests thinking of sizeof as a function
and add parenthesis.
Signed-off-by: Zhiqi Song <songzhiqi1@huawei.com>
Link: https://lore.kernel.org/r/1621301902-64158-6-git-send-email-songzhiqi1@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix missing parenthesis of sizeof reported by checkpatch.pl:
WARNING: sizeof *pp should be sizeof(*pp).
The kernel coding style suggests thinking of sizeof as a function
and add parenthesis.
Signed-off-by: Zhiqi Song <songzhiqi1@huawei.com>
Link: https://lore.kernel.org/r/1621301902-64158-5-git-send-email-songzhiqi1@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix missing parenthesis of sizeof reported by checkpatch.pl:
WARNING: sizeof *pp should be sizeof(*pp).
The kernel coding style suggests thinking of sizeof as a function
and add parenthesis.
Signed-off-by: Zhiqi Song <songzhiqi1@huawei.com>
Link: https://lore.kernel.org/r/1621301902-64158-4-git-send-email-songzhiqi1@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix missing parenthesis of sizeof reported by checkpatch.pl:
WARNING: sizeof *pp should be sizeof(*pp).
The kernel coding style suggests thinking of sizeof as a function
and add parenthesis.
Signed-off-by: Zhiqi Song <songzhiqi1@huawei.com>
Link: https://lore.kernel.org/r/1621301902-64158-3-git-send-email-songzhiqi1@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix missing parenthesis of sizeof reported by checkpatch.pl:
WARNING: sizeof *pp should be sizeof(*pp).
The kernel coding style suggests thinking of sizeof as a function
and add parenthesis.
Cc: Kaiwan N Billimoria <kaiwan@designergraphix.com>
Signed-off-by: Zhiqi Song <songzhiqi1@huawei.com>
Link: https://lore.kernel.org/r/1621301902-64158-2-git-send-email-songzhiqi1@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
One of the author names got an invalid char, probably due to
a bad charset conversion, being replaced by the
REPLACEMENT CHARACTER U+fffd ('�').
Use the author's e-mail has the characters without accents,
as also used at the .mailmap file.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/ff8d296e1fdcc4f1c6df94434a5720bcedcd0ecf.1621412009.git.mchehab+huawei@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
The predefined mask for threshold modification can be used
in case of Intel Merrifield SPI. Replace open-coded value
with predefined mask when programming FIFO thresholds.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210517140351.901-10-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The struct chip_data had been introduced in order to keep the parameters
that may be provided on stack during device allocation. There is no need
to duplicate parameters there, which are carried on by SPI device itself.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210517140351.901-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
SPI core may utilize properties and resources provided by the parent device.
Propagate firmware node to the child SPI controller device for that.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210517140351.901-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
When a spi device is unregistered and triggers a driver unbind, the
driver might need to access the spi device. So, don't have the
controller clean up the spi device before the driver is unbound. Clean
up the spi device after the driver is unbound.
Fixes: c7299fea67 ("spi: Fix spi device unregister flow")
Reported-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Tested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210505164734.175546-1-saravanak@google.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Currently GPIO CS handling, when descriptors are in use, doesn't
take into consideration that in ACPI case the default polarity
is Active High and can't be altered. Instead we have to use the
per-chip definition provided by SPISerialBus() resource.
Fixes: 766c6b63aa ("spi: fix client driver breakages when using GPIO descriptors")
Cc: Liguang Zhang <zhangliguang@linux.alibaba.com>
Cc: Jay Fang <f.fangjian@huawei.com>
Cc: Sven Van Asbroeck <thesven73@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Xin Hao <xhao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20210511140912.30757-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
MODULE_DEVICE_TABLE is used to extract the device information out of the
driver and builds a table when being compiled. If using this macro,
kernel can find the driver if available when the device is plugged in,
and then loads that driver and initializes the device.
Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Link: https://lore.kernel.org/r/20210512093534.243040-1-zhang.lyra@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>