13 Commits

Author SHA1 Message Date
Mirko Vogt
29a5258c6b spi: spi-sun6i: Fix chipselect/clock bug
[ Upstream commit 0d7993b234c9fad8cb6bec6adfaa74694ba85ecb ]

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: 3558fe900e8af (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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20 16:21:01 +02:00
Marc Kleine-Budde
34319cf5f8 spi: spi-sun6i: sun6i_spi_transfer_one(): fix setting of clock rate
[ Upstream commit ed7815db70d17b1741883f2da8e1d80bc2efe517 ]

A SPI transfer defines the _maximum_ speed of the SPI transfer. However the
driver doesn't take into account that the clock divider is always rounded down
(due to integer arithmetics). This results in a too high clock rate for the SPI
transfer.

E.g.: with a mclk_rate of 24 MHz and a SPI transfer speed of 10 MHz, the
original code calculates a reg of "0", which results in a effective divider of
"2" and a 12 MHz clock for the SPI transfer.

This patch fixes the issue by using DIV_ROUND_UP() instead of a plain
integer division.

While there simplify the divider calculation for the CDR1 case, use
order_base_2() instead of two ilog2() calculations.

Fixes: 3558fe900e8a ("spi: sunxi: Add Allwinner A31 SPI controller driver")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Maxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/20200706143443.9855-2-mkl@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-07-22 09:10:50 +02:00
Tobias Jordan
26cae37274 spi: sun6i: disable/unprepare clocks on remove
[ Upstream commit 2d9bbd02c54094ceffa555143b0d68cd06504d63 ]

sun6i_spi_probe() uses sun6i_spi_runtime_resume() to prepare/enable
clocks, so sun6i_spi_remove() should use sun6i_spi_runtime_suspend() to
disable/unprepare them if we're not suspended.
Replacing pm_runtime_disable() by pm_runtime_force_suspend() will ensure
that sun6i_spi_runtime_suspend() is called if needed.

Found by Linux Driver Verification project (linuxtesting.org).

Fixes: 3558fe900e8af (spi: sunxi: Add Allwinner A31 SPI controller driver)
Signed-off-by: Tobias Jordan <Tobias.Jordan@elektrobit.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-22 09:17:56 +01:00
Mark Brown
1cb2e84873 Merge remote-tracking branches 'spi/topic/spidev', 'spi/topic/sunxi', 'spi/topic/ti-qspi', 'spi/topic/topcliff-pch' and 'spi/topic/txx9' into spi-next 2016-07-24 22:08:27 +01:00
Michal Suchanek
0b06d8cf4f spi: sunxi: set maximum and minimum speed of SPI master
The speed limits are unset in the sun4i and sun6i SPI drivers.

The maximum speed of SPI master is used when maximum speed of SPI slave
is not specified. Also the __spi_validate function should check that
transfer speeds do not exceed the master limits.

The user manual for A10 and A31 specifies maximum
speed of the SPI clock as 100MHz and minimum as 3kHz.

Setting the SPI clock to out-of-spec values can lock up the SoC.

Signed-off-by: Michal Suchanek <hramrach@gmail.com>
--
v2:
new patch
v3:
fix constant style
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-06-27 19:18:35 +01:00
Michal Suchanek
719bd65420 spi: sunxi: fix transfer timeout
The trasfer timeout is fixed at 1000 ms. Reading a 4Mbyte flash over
1MHz SPI bus takes way longer than that. Calculate the timeout from the
actual time the transfer is supposed to take and multiply by 2 for good
measure.

Signed-off-by: Michal Suchanek <hramrach@gmail.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
2016-06-14 10:05:18 +01:00
Michal Suchanek
794912cff6 spi: sunxi: expose maximum transfer size limit
The sun4i spi hardware can trasfer at most 63 bytes of data without DMA
support so report the limitation. Same for sun6i.

Signed-off-by: Michal Suchanek <hramrach@gmail.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-06-14 10:04:42 +01:00
Marcus Weseloh
47284e3e0f spi: sun4i: allow transfers to set transmission speed
Allow transfers to set the transmission speed rather than using the
device max_speed_hz value. The SPI core makes sure that the speed_hz
value is always set on the transfer.

Signed-off-by: Marcus Weseloh <mweseloh42@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-11-18 18:34:56 +00:00
Wolfram Sang
14ac00e033 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>
2014-10-20 16:21:36 +02:00
Axel Lin
e4745fef55 spi: Remove unneeded include of linux/workqueue.h
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-04-14 17:20:15 +01:00
Axel Lin
743a46b89a spi: sun6i: Set bits_per_word_mask to only support 8 bits word length
This controller only supports 8 bits word length.
Set bits_per_word_mask so spi core will reject transfers that attempt to use
an unsupported bits_per_word value.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-03-04 11:08:06 +08:00
Axel Lin
d31ad46f58 spi: sun6i: Fix define for SUN6I_TFR_CTL_CS_MASK
Current code in sun6i_spi_set_cs() actually clears CPHA and CPOL bits which is
obvious wrong. The define for SUN6I_TFR_CTL_CS_MASK is wrong. Fix it.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-02-16 09:11:05 +08:00
Maxime Ripard
3558fe900e spi: sunxi: Add Allwinner A31 SPI controller driver
The Allwinner A31 has a new SPI controller IP compared to the older Allwinner
SoCs.

It supports DMA, but the driver only does PIO for now, and DMA will be
supported eventually.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-02-05 14:58:36 +00:00