Between SPI transactions, all SPI pins are in HiZ state. When using the SS
signal from the SPICC controller it's not an issue because when the
transaction resumes all pins come back to the right state at the same time
as SS.
The problem is when we use CS as a GPIO. In fact, between the GPIO CS
state change and SPI pins state change from idle, you can have a missing or
spurious clock transition.
Set a bias on the clock depending on the clock polarity requested before CS
goes active, by passing a special "idle-low" and "idle-high" pinctrl state
and setting the right state at a start of a message
Reported-by: Da Xue <da@libre.computer>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Amjad Ouled-Ameur <aouledameur@baylibre.com>
Link: https://lore.kernel.org/r/20221004-up-aml-fix-spi-v4-2-0342d8e10c49@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The sparse tool complains as follows:
drivers/spi/spi-meson-spicc.c:570:22: warning:
symbol 'meson_spicc_pow2_clk_ops' was not declared. Should it be static?
This symbol is not used outside of spi-meson-spicc.c, so marks it static.
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20220922040807.1409540-1-weiyongjun@huaweicloud.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Since [1], controller's busy flag isn't set anymore when the
__spi_transfer_message_noqueue() is used instead of the
__spi_pump_transfer_message() logic for spi_sync transfers.
Since the pow2 clock ops were limited to only be available when a
transfer is ongoing (between prepare_transfer_hardware and
unprepare_transfer_hardware callbacks), the only way to track this
down is to check for the controller cur_msg.
[1] ae7d2346dc ("spi: Don't use the message queue if possible in spi_sync")
Fixes: 09992025da ("spi: meson-spicc: add local pow2 clock ops to preserve rate between messages")
Fixes: ae7d2346dc ("spi: Don't use the message queue if possible in spi_sync")
Reported-by: Markus Schneider-Pargmann <msp@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Tested-by: Markus Schneider-Pargmann <msp@baylibre.com>
Link: https://lore.kernel.org/r/20220908121803.919943-1-narmstrong@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>
At the end of a message, the HW gets a reset in meson_spicc_unprepare_transfer(),
this resets the SPICC_CONREG register and notably the value set by the
Common Clock Framework.
This is problematic because:
- the register value CCF can be different from the corresponding CCF cached rate
- CCF is allowed to change the clock rate whenever the HW state
This introduces:
- local pow2 clock ops checking the HW state before allowing a clock operation
- separation of legacy pow2 clock patch and new enhanced clock path
- SPICC_CONREG datarate value is now value kepts across messages
It has been checked that:
- SPICC_CONREG datarate value is kept across messages
- CCF is only allowed to change the SPICC_CONREG datarate value when busy
- SPICC_CONREG datarate value is correct for each transfer
This didn't appear before commit 3e0cf4d3fc ("spi: meson-spicc: add a linear clock divider support")
because we recalculated and wrote the rate for each xfer.
Fixes: 3e0cf4d3fc ("spi: meson-spicc: add a linear clock divider support")
Reported-by: Da Xue <da@libre.computer>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20220811134445.678446-1-narmstrong@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This check misses checking for platform_get_irq()'s call and may passes
the negative error codes to devm_request_irq(), which takes unsigned IRQ #,
causing it to fail with -EINVAL, overriding an original error code.
Stop calling devm_request_irq() with invalid IRQ #s.
Fixes: 454fa271bc ("spi: Add Meson SPICC driver")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Link: https://lore.kernel.org/r/20220126110447.24549-1-linmq006@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
In meson_spicc_probe, the error handling code needs to clean up master
by calling spi_master_put, but the remove function does not have this
function call. This will lead to memory leak of spicc->master.
Reported-by: Dongliang Mu <mudongliangabcd@gmail.com>
Fixes: 454fa271bc4e("spi: Add Meson SPICC driver")
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Link: https://lore.kernel.org/r/20210720100116.1438974-1-mudongliangabcd@gmail.com
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>
Looks like it hasn't ever been checked.
Fixes the following W=1 kernel build warning(s):
drivers/spi/spi-meson-spicc.c: In function ‘meson_spicc_reset_fifo’:
drivers/spi/spi-meson-spicc.c:365:6: warning: variable ‘data’ set but not used [-Wunused-but-set-variable]
365 | u32 data;
| ^~~~
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: linux-amlogic@lists.infradead.org
Link: https://lore.kernel.org/r/20200717135424.2442271-7-lee.jones@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Add support for the SPICC controllers on the Amlogic G12A SoCs family.
The G12A SPICC controllers inherit from the AXG enhanced registers but
takes an external pclk for the baud rate generator and can achieve up to
166MHz SCLK.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20200312133131.26430-10-narmstrong@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The G12A SPICC controller variant has a different FIFO size and doesn't
handle the RX Half interrupt the same way as GXL & AXG variants.
Thus simplify the burst management and take in account a variable FIFO
size.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20200312133131.26430-8-narmstrong@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Now the controller can support frequencies higher than 30MHz, we need
the setup the I/O line delays in regard of the SPI clock frequency.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20200312133131.26430-7-narmstrong@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The G12A SPICC controller variant takes the source clock from a specific
clock instead of the bus clock.
The minimal clock calculus won't work with the G12A support, thus add the
minimal supported clock for each variant and pass this to the SPI core.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20200312133131.26430-6-narmstrong@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The SPICC controller in Meson-AXG is capable of running at 80M clock.
The ASIC IP is improved and the clock is actually running higher than
previous old SoCs.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
Signed-off-by: Sunny Luo <sunny.luo@amlogic.com>
Link: https://lore.kernel.org/r/20200312133131.26430-5-narmstrong@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The SPICC controller in Meson-AXG SoC is capable of using
a linear clock divider to reach a much fine tuned range of clocks,
while the old controller only use a power of two clock divider,
result at a more coarse clock range.
Also convert the clock registration into Common Clock Framework.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
Signed-off-by: Sunny Luo <sunny.luo@amlogic.com>
Link: https://lore.kernel.org/r/20200312133131.26430-4-narmstrong@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The SPICC controller in Meson-AXG is capable of driving the CLK/MOSI/SS
signal lines through the idle state (between two transmission operation),
which avoid the signals floating in unexpected state.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
Signed-off-by: Sunny Luo <sunny.luo@amlogic.com>
Link: https://lore.kernel.org/r/20200312133131.26430-3-narmstrong@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Instead of grabbing GPIOs using the legacy interface and
handling them in the setup callback, just let the core
grab and use the GPIOs using descriptors.
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Sunny Luo <sunny.luo@amlogic.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20191205083915.27650-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Use devm_platform_ioremap_resource() to simplify the code a bit.
This is detected by coccinelle.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20190904135918.25352-16-yuehaibing@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
If devm_spi_register_master() fails in meson_spicc_probe(),
spicc->core is left undisabled. The patch fixes that.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Add new compatible string to support SPICC controller which
found at Amlogic Meson-AXG SoC. This is aiming at adding
a couple of enhanced feature patches.
Signed-off-by: Sunny Luo <sunny.luo@amlogic.com>
Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The SPICC hardware block on the Amlogic SoCs is Communication oriented and
can do Full-Duplex 8- to 32-bit width SPI transfers up to 30MHz.
The current driver only supportd the PIO transfer mode since the DMA seems
broken on available hardware.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
