Dynamic burst mode allows to group together multiple words and send them
in one continuous burst. When the number of bytes to be sent is not a
strict multiple of the FIFO entry size (32 bits), the controller expects
the non aligned bits to be sent first.
This commit adds support for this particular constraint, avoiding the
need to send the non-aligned bytes one by one at the end of the
transfer, speeding-up transfer speed in that case.
With this method, a transfer is divided into multiple bursts, limited in
size by the maximum amount of data that the controller can transfer in
one continuous burst (which is 512 bytes).
The non-512 byte part of the transfer is sent first. The remaining bytes
to be transferred in the current burst is stored in the 'remainder'
field.
With this method, the read_u32 field is no longer necessary, and is
removed.
This was tested on imx6 solo and imx6 quad.
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The spi_imx_can_dma function computes the watermark level so that
the transfer will fit in exactly N bursts (without a remainder).
The smallest watermark level possible being one FIFO entry per burst, we
can't never have a case where the transfer size isn't divsiible by 1.
Remove the extra check for the wml being different than 0.
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The SPI core enforces that we always use the next power-of-two number of
bytes to store words. As a result, a 24 bits word will be stored in 4
bytes.
This commit fixes the spi_imx_bytes_per_word function to return the
correct number of bytes.
This also allows to get rid of unnecessary checks in the can_dma
function, since the SPI core validates that we always have a transfer
length that is a multiple of the number of bytes per word.
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The dynamic bursts mode allows to group together multiple words into a
single burst. To do so, it's necessary that words can be packed into the
32-bits FIFO entries, so we can't allow using this mode with bit_per_words
different to 8, 16 or 32.
This prevents shitfing out extra clock ticks for transfers with
bit_per_word values not aligned on 8 bits.
With that , we are sure that only the correct number of bits is
shifted out at each transfer, so we don't need to mask out the remaining
parts of the words.
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Some fields in struct spi_imx_data are assigned a different value twice
in a row, in spi_imx_setupxfer.
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Adopt the SPDX license identifier headers to ease license compliance
management.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Now i.MX SPI controller can work in Slave mode.
Update MODULE_DESCRIPTION to "SPI Controller driver".
Signed-off-by: wangbo <wang.bo116@zte.com.cn>
Signed-off-by: Mark Brown <broonie@kernel.org>
Since clocks are disabled except during message transfer clocks
are also disabled when spi_imx_remove gets called. Accessing
registers leads to a freeeze at least on a i.MX 6ULL. Enable
clocks before disabling accessing the MXC_CSPICTRL register.
Fixes: 9e556dcc55 ("spi: spi-imx: only enable the clocks when we start to transfer a message")
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
If the array is not present, assume all chip selects are native. This
is the standard behavior for SPI masters configured via the device
tree and the behavior of this driver as well when it is configured via
device tree.
This reduces platform data vs DT differences and allows most of the
platform data based boards to remove their chip select arrays.
CC: Shawn Guo <shawnguo@kernel.org>
CC: Sascha Hauer <kernel@pengutronix.de>
CC: Fabio Estevam <fabio.estevam@nxp.com>
CC: Mark Brown <broonie@kernel.org>
Signed-off-by: Trent Piepho <tpiepho@impinj.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
If the code that requests any chip select GPIOs fails, the cleanup of
spi_bitbang_start() by calling spi_bitbang_stop() is not done. Add this
to the failure path.
Note that spi_bitbang_start() has to be called before requesting GPIOs
because the GPIO data in the spi master is populated when the master is
registed, and that doesn't happen until spi_bitbang_start() is called.
CC: Shawn Guo <shawnguo@kernel.org>
CC: Sascha Hauer <kernel@pengutronix.de>
CC: Fabio Estevam <fabio.estevam@nxp.com>
CC: Mark Brown <broonie@kernel.org>
CC: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Trent Piepho <tpiepho@impinj.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The driver will fail to load if no gpio chip selects are specified,
this patch changes this so that it no longer fails.
It's possible to use all native chip selects, in which case there is
no reason to have a gpio chip select array. This is what happens if
the *optional* device tree property "cs-gpios" is omitted.
The spi core already checks for the absence of gpio chip selects in
the master and assigns any slaves the gpio_cs value of -ENOENT.
Also have the driver respect the standard SPI device tree property "num-cs"
to allow setting the number of chip selects without using cs-gpios.
CC: Mark Brown <broonie@kernel.org>
CC: Shawn Guo <shawnguo@kernel.org>
CC: Sascha Hauer <kernel@pengutronix.de>
CC: Fabio Estevam <fabio.estevam@nxp.com>
CC: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Trent Piepho <tpiepho@impinj.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
In commit 974488e4ce ("spi: imx: Fix failure path leak on GPIO request
error"), spi_bitbang_start() was moved later in the probe sequence. But
this doesn't work, as spi_bitbang_start() has to be called before
requesting GPIOs because the GPIO data in the spi master is populated when
the master is registed, and that doesn't happen until spi_bitbang_start()
is called. The default only works if one uses one CS.
So add a failure path call to spi_bitbang_stop() to fix the leak.
CC: Shawn Guo <shawnguo@kernel.org>
CC: Sascha Hauer <kernel@pengutronix.de>
CC: Fabio Estevam <fabio.estevam@nxp.com>
CC: Mark Brown <broonie@kernel.org>
CC: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Trent Piepho <tpiepho@impinj.com>
Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
If the code that requests any chip select GPIOs fails, the cleanup of
spi_bitbang_start() by calling spi_bitbang_stop() is not done.
Fix this by moving spi_bitbang_start() to after the code that requets
GPIOs. The GPIOs are dev managed and don't need explicit cleanup.
Since spi_bitbang_start() is now the last operation, it doesn't need
to be cleaned up in the failure path.
CC: Shawn Guo <shawnguo@kernel.org>
CC: Sascha Hauer <kernel@pengutronix.de>
CC: Fabio Estevam <fabio.estevam@nxp.com>
CC: Mark Brown <broonie@kernel.org>
Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Trent Piepho <tpiepho@impinj.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Previously i.MX SPI controller only works in Master mode.
This patch adds support to i.MX51, i.MX53 and i.MX6 ECSPI
controller to work also in Slave mode.
Currently SPI Slave mode support patch has the following limitations:
1. The stale data in RXFIFO will be dropped when the Slave does any new
transfer.
2. One transfer can be finished only after all transfer->len data been
transferred to master device
3. Slave device only accepts transfer->len data. Any data longer than this
from master device will be dropped. Any data shorter than this from
master will cause SPI to stuck due to mentioned HW limitation 2.
4. Only PIO transfer is supported in Slave mode.
5. Dynamic burst size adjust isn't supported in Slave mode.
Following HW limitation applies:
1. ECSPI has a HW issue when works in Slave mode, after 64
words written to TXFIFO, even TXFIFO becomes empty,
ECSPI_TXDATA keeps shift out the last word data,
so we have to disable ECSPI when in slave mode after the
transfer completes
2. Due to Freescale errata ERR003775 "eCSPI: Burst completion by Chip
Select (SS) signal in Slave mode is not functional" burst size must
be set exactly to the size of the transfer. This limit SPI transaction
with maximum 2^12 bits. This errata affects i.MX53 and i.MX6 ECSPI
controllers.
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The commonly used mechanism of specifying the hardware or native
chip-select on an SPI device in devicetree (that is "cs-gpios = <0>")
does not result in the native chip-select being configured for use.
So external SPI devices that require use of the native chip-select
will not work.
You can successfully specify native chip-selects if using a platform
setup by specifying the cs-gpio as negative offset by 32. And that
works correctly. You cannot use the same method in devicetree.
The logic in the spi-imx.c driver during probe uses core spi function
of_spi_register_master() in spi.c to parse the "cs-gpios" devicetree tag.
For valid GPIO values that will be recorded for use, all other entries in
the cs_gpios list will be set to -ENOENT. So entries like "<0>" will be
set to -ENOENT in the cs_gpios list.
When the SPI device registers are setup the code will use the GPIO
listed in the cs_gpios list for the desired chip-select. If the cs_gpio
is less then 0 then it is intended to be for a native chip-select, and
its cs_gpio value is added to 32 to get the chipselect number to use.
Problem is that with devicetree this can only ever be -ENOENT (which
is -2), and that alone results in an invalid chip-select number. But also
doesn't allow selection of the native chip-select at all.
To fix, if the cs_gpio specified for this spi device is not a
valid GPIO then use the "chip_select" (that is the native chip-select
number) for hardware setup.
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Tested-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The newly added dynamic burst code produces a harmless warning
on big-endian configurations:
drivers/spi/spi-imx.c: In function 'spi_imx_buf_rx_swap_u32':
drivers/spi/spi-imx.c:284:15: error: unused variable 'bytes_per_word' [-Werror=unused-variable]
unsigned int bytes_per_word;
^~~~~~~~~~~~~~
drivers/spi/spi-imx.c: In function 'spi_imx_buf_tx_swap_u32':
drivers/spi/spi-imx.c:319:15: error: unused variable 'bytes_per_word' [-Werror=unused-variable]
unsigned int bytes_per_word;
This adds another #ifdef around the variable declaration matching
the one on the use.
Fixes: 1673c81d94 ("spi: imx: dynamic burst length adjust for PIO mode")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
previously burst length (BURST_LENGTH) is always set to equal
to bits_per_word, causes a 10us gap between each word in
transfer, which significantly affects performance.
This patch uses 32 bits transfer to simulate lower bits transfer,
and adjusts burst length runtimely to use biggeest burst length
as possible to reduce the gaps in transfer for PIO mode.
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
To run spi-loopback-tests on HW without modifications, we need to
disable Chip Select. This should avoid surprising side effects for SPI devices
by testing patterns.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
ECSPI contorller for iMX53 and iMX6 has few hardware issues
comparing to iMX51.
The change add possibility to detect which controller is used
to apply possible workaround and limitations.
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Different ECSPI controller has different fifosize and DMA capability,
instead of calling functions to identify these information by check
devtype. add fifo_size and has_dmamode to spi_imx_devtype_data.
so that these information can be directly accessed.
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
In case of spi_alloc_master() failure it is better to return the
error immediately, so move the error check right after the allocation.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
'bpw' is ambiguous and only the context makes sure if bytes_per_word
or bits_per_word is meant. Use the full names instead to make reading
the code easier.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
We already have bits_per_word in the private driver struct and
bytes_per_word can be calculated from it, so remove bits_per_word.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
It's unnecessary to call spi_imx_dma_configure() from probe(). It will
be called later anyway again when an actual DMA transfer is prepared.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
struct spi_imx_config used to hold data specific to the current
transfer. However, other data is in the drivers private data struct.
Let's drop struct spi_imx_config and put the variables into the
drivers private data struct aswell.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
__spi_validate makes sure that every transfer has a valid bits_per_word
and speed_hz setting. We do not need to fallback to values from the
spi_device.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
When the spi_transfer given in spi_imx_setupxfer is NULL then
we have nothing to do. Bail out early in this case so that
we do not have to test for t != NULL multiple times later.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
This reverts commits 8d4a6cad7a and
179547e143.
Besides the problems already found with this patch it also modifies
the spi transfer tx_buf in spi_imx_u32_swap_u8() and spi_imx_u32_swap_u16().
This is hidden from the compiler with an explicit cast from const void*
to u32*, so no warning is issued.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
In case either transfer->tx_buf or transfer->rx_buf is NULL,
manipulation of buffer in spi_imx_u32_swap_u[8|16]() will cause
NULL pointer dereference crash.
Add buffer check at very beginning of spi_imx_u32_swap_u[8|16](),
to avoid such crash.
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Reported-by: Leonard Crestez <leonard.crestez@nxp.com>
Tested-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
previously burst length (BURST_LENGTH) is always set to equal
to bits_per_word, causes a 10us gap between each word in
transfer, which significantly affects performance.
This patch uses 32 bits transfer to simulate lower bits transfer,
and adjusts burst length runtimely to use biggeest burst length
as possible to reduce the gaps in transfer for PIO mode.
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This patch implements consideration of the SPI_READY mode flag as
defined in spi.h. It extends the device tree bindings to support
the values defined by the reference manual for the DRCTL field.
Thus supporting edge-triggered and level-triggered bursts.
Signed-off-by: Leif Middelschulte <Leif.Middelschulte@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Previously DMA watermark level is configured to fifosize/2,
DMA mode can be used only when transfer length can be divided
by 'watermark level * bpw', which makes DMA mode not pratical.
This patch adjusts watermark level to largest number (no bigger
than fifosize/2) which can divide 'tranfer length / bpw' for
each transfer.
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Introduce additional output parameter in spi_imx_clkdiv_1()
function to return result frequency and set it to spi_bus_clk.
This fixes division by zero bug, which occurred in
spi_imx_calculate_timeout() function.
Signed-off-by: Robert Baldyga <r.baldyga@hackerion.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Support DMA transfers on imx35 and compatible chipsets (imx31, imx25).
If DMA can be used, set the start mode control (SMC) bit to start the
SPI burst as soon as data is written into the tx fifo. Configure DMA
requests when the fifo is half empty during tx or half full during rx.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix to return error code -EINVAL if no CS GPIOs available
instead of 0, as done elsewhere in this function.
Fixes: f13d4e189d ("spi: imx: Gracefully handle NULL master->cs_gpios")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
It is possible that master->cs_gpios is NULL after spi_bitbang_start(),
this happens if the master has no CS GPIOs specified in DT. Check for
this case after spi_bitbang_start() to prevent NULL pointer dereference
in the subsequent for loop, which accesses the master->cs_gpios field.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Martin Kaiser <martin@kaiser.cx>
Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
imx35 and compatible chipsets support loopback mode by setting a
loopback control bit in the test register. Make this setting available
for data transfers, similar to what we do for imx51.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Mark Brown <broonie@kernel.org>
Modify spi_imx_clkdiv_2() to return the resulting bus clock frequency
when the selected clock divider is applied. Set spi_imx->spi_bus_clk to
this frequency.
If spi_bus_clk is unset, spi_imx_calculate_timeout() causes a
division by 0.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Mark Brown <broonie@kernel.org>
The SPI-driver no longer contains the conditions for various CPUs, so
"maybe_unused" attributes is no longer needed.
This patch removes these attributes.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Mark Brown <broonie@kernel.org>
SPI mode can be obtained directly from spi-device, there is no
need to keep a copy.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Mark Brown <broonie@kernel.org>
Patch reuse existing "chip_select" and "cs_gpio(s)" fields from SPI core.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Mark Brown <broonie@kernel.org>
transfer could be NULL in spi_imx_can_dma() when it's called from
spi_imx_setupxfer() with a NULL transfer. Test for a NULL pointer before
dereferencing it.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
If the SPI chip select (CS) for a dedicated channel is done manually by
the used higher device driver, the CS may be active while writing to
ECSPIx_CONFIGREG. To prevent unwanted clock edges when selecting
the clock mode, only do the necessary changes to the i.MX SPI
configuration register and leave not selected channels untouched.
To prevent unwanted clock edges on first use, an empty dummy
transmission shall be done by the initialization procedure of the device
driver of this channel. This will set the clock mode to the correct state.
Signed-off-by: Knut Wohlrab <knut.wohlrab@de.bosch.com>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
The driver tries to be clever by only setting up DMA channels when
the corresponding sg tables are non NULL. The sg tables are embedded
structs in struct spi_transfer, so they are guaranteed to be non NULL
which makes the if(tx)/if(rx) tests completely bogus. The driver even
sets the SPI_MASTER_MUST_RX / SPI_MASTER_MUST_TX flags which makes sure
the sg tables are not only present but also non empty.
Drop the tests and make the DMA path easier to follow.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Now that the config function knows whether we are doing DMA or not we
can do the necessary register setup in the config function and no longer
have to do this in the trigger function. With this the trigger function
becomes a no-op for DMA, so instead of testing if we are doing DMA or
not in the trigger function we simply no longer call it in the DMA case.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
The watermark levels in the DMA register are write only, the driver
should never have to read them back from the hardware. Replace the
current _MASK and _OFFSET defines with defines taking the watermark
level directly.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
This reverts patch 1476253cef (spi: imx: fix ecspi mode setup)
The patch tried to fix something by clearing bits in the cfg variable,
but cfg is initialized to zero on function entry. There are no bits to
clear.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Maxime Chevallier