Commit Graph

16 Commits

Author SHA1 Message Date
Amit Kumar Mahapatra via Alsa-devel
9e264f3f85
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>
2023-03-11 12:34:01 +00:00
Eddie James
40308f9642
spi: fsi: Increase timeout and ensure status is checked
Only timeout after at least one iteration of checking the
status registers. In addition, increase the transfer timeout
to 1 second.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20220623140547.71762-1-eajames@linux.ibm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-06-23 15:48:21 +01:00
Eddie James
61bf40ef51
spi: fsi: Fix spurious timeout
The driver may return a timeout error even if the status register
indicates that the transfer may proceed. Fix this by restructuring
the polling loop.

Fixes: 89b35e3f28 ("spi: fsi: Implement a timeout for polling status")
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20220525165852.33167-2-eajames@linux.ibm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-05-26 14:43:28 +01:00
Eddie James
89b35e3f28
spi: fsi: Implement a timeout for polling status
The data transfer routines must poll the status register to
determine when more data can be shifted in or out. If the hardware
gets into a bad state, these polling loops may never exit. Prevent
this by returning an error if a timeout is exceeded.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20220317211426.38940-1-eajames@linux.ibm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-03-18 16:05:08 +00:00
Eddie James
e954af1343
spi: fsi: Fix contention in the FSI2SPI engine
There was nothing to protect multiple SPI controllers on the same FSI2SPI
device from being accessed through the FSI2SPI device at the same time.
For example, multiple writes to the command and data registers might occur
for different SPI controllers, resulting in complete chaos in the SPI
engine. To prevent this, add a FSI2SPI device level mutex and lock it in
the SPI register read and write functions.

Fixes: bbb6b2f986 ("spi: Add FSI-attached SPI controller driver")
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20211026193327.52420-1-eajames@linux.ibm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-10-27 11:31:27 +01:00
Eddie James
48a78c66ad
spi: fsi: Print status on error
Print the SPI engine status register when an error is detected. This
will aid tremendously in debugging failed transactions.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20211004195149.29759-1-eajames@linux.ibm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-10-05 13:10:01 +01:00
Eddie James
34d34a56a5
spi: fsi: Reduce max transfer size to 8 bytes
Security changes have forced the SPI controllers to be limited to
8 byte reads. Refactor the sequencing to just handle 8 bytes at a
time.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20210716133915.14697-2-eajames@linux.ibm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
2021-07-19 16:56:14 +01:00
Christophe JAILLET
24b5515aa3
spi: fsi: add a missing of_node_put
'for_each_available_child_of_node' performs an of_node_get on each
iteration, so a return from the middle of the loop requires an of_node_put.

Fixes: bbb6b2f986 ("spi: Add FSI-attached SPI controller driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/504e431b900341249d331b868d90312cf41f415a.1618947919.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-04-21 16:07:04 +01:00
Eddie James
3ed4c84cc7
spi: fsi: Remove multiple sequenced ops for restricted chips
Updated restricted chips have trouble processing multiple sequenced
operations. So remove the capability to sequence multiple operations and
reduce the maximum transfer size to 8 bytes.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20210324220516.41192-1-eajames@linux.ibm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-03-25 13:59:44 +00:00
Eddie James
ee4ad5d065
spi: fsi: Fix transfer returning without finalizing message
In the case that the SPI mux isn't set, the transfer_one_message
function returns without finalizing the message. This means that
the transfer never completes, resulting in hung tasks and an
eventual kernel panic. Fix it by finalizing the transfer in this
case.

Fixes: 9211a441e6 ("spi: fsi: Check mux status before transfers")
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20201110214736.25718-1-eajames@linux.ibm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-11-11 12:34:29 +00:00
Eddie James
9211a441e6
spi: fsi: Check mux status before transfers
The SPI controllers are not accessible if the mux isn't set. Therefore,
check the mux status before starting a transfer and fail out if it isn't
set.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200909222857.28653-7-eajames@linux.ibm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-09-17 19:31:43 +01:00
Eddie James
49c9fc1d7c
spi: fsi: Implement restricted size for certain controllers
Some of the FSI-attached SPI controllers cannot use the loop command in
programming the sequencer due to security requirements. Check the
devicetree compatibility that indicates this condition and restrict the
size for these controllers. Also, add more transfers directly in the
sequence up to the length of the sequence register.

Fixes: bbb6b2f986 ("spi: Add FSI-attached SPI controller driver")
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200909222857.28653-6-eajames@linux.ibm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-09-17 19:31:42 +01:00
Brad Bishop
7909eebb2b
spi: fsi: Fix use of the bneq+ sequencer instruction
All of the switches in N2_count_control in the counter configuration are
required to make the branch if not equal and increment command work.
Set them when using bneq+.

A side effect of this mode requires a dummy write to TDR when both
transmitting and receiving otherwise the controller won't start shifting
receive data.

It is likely not possible to avoid TDR underrun errors in this mode and
they are harmless, so do not check for them.

Fixes: bbb6b2f986 ("spi: Add FSI-attached SPI controller driver")
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200909222857.28653-4-eajames@linux.ibm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-09-17 19:31:41 +01:00
Brad Bishop
0b546bbe94
spi: fsi: Fix clock running too fast
Use a clock divider tuned to a 200MHz FSI bus frequency (the maximum). Use
of the previous divider at 200MHz results in corrupt data from endpoint
devices. Ideally the clock divider would be calculated from the FSI clock,
but that would require some significant work on the FSI driver. With FSI
frequencies slower than 200MHz, the SPI clock will simply run slower, but
safely.

Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200909222857.28653-3-eajames@linux.ibm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-09-17 19:31:40 +01:00
Brad Bishop
2b3cef0fc7
spi: fsi: Handle 9 to 15 byte transfers lengths
The trailing <len> - 8 bytes of transfer data in this size range is no
longer ignored.

Fixes: bbb6b2f986 ("spi: Add FSI-attached SPI controller driver")
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200909222857.28653-2-eajames@linux.ibm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-09-17 19:31:39 +01:00
Eddie James
bbb6b2f986
spi: Add FSI-attached SPI controller driver
There exists a set of SPI controllers on some POWER processors that may
be accessed through the FSI bus. Add a driver to traverse the FSI CFAM
engine that can access and drive the SPI controllers. This driver would
typically be used by a baseboard management controller (BMC).

The SPI controllers operate by means of programming a sequencing engine
which automatically manages the usual SPI protocol buses. The driver
programs each transfer into the sequencer as various operations
specifying the slave chip and shifting data in and out on the lines.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20200306194118.18581-3-eajames@linux.ibm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-10 14:11:57 +00:00