Commit Graph

4820 Commits

Author SHA1 Message Date
Lukas Wunner
9dd277ff92
spi: bcm2835: Fix controller unregister order
The BCM2835 SPI driver uses devm_spi_register_controller() on bind.
As a consequence, on unbind, __device_release_driver() first invokes
bcm2835_spi_remove() before unregistering the SPI controller via
devres_release_all().

This order is incorrect:  bcm2835_spi_remove() tears down the DMA
channels and turns off the SPI controller, including its interrupts
and clock.  The SPI controller is thus no longer usable.

When the SPI controller is subsequently unregistered, it unbinds all
its slave devices.  If their drivers need to access the SPI bus,
e.g. to quiesce their interrupts, unbinding will fail.

As a rule, devm_spi_register_controller() must not be used if the
->remove() hook performs teardown steps which shall be performed
after unbinding of slaves.

Fix by using the non-devm variant spi_register_controller().  Note that
the struct spi_controller as well as the driver-private data are not
freed until after bcm2835_spi_remove() has finished, so accessing them
is safe.

Fixes: 247263dba2 ("spi: bcm2835: use devm_spi_register_master()")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org # v3.13+
Link: https://lore.kernel.org/r/2397dd70cdbe95e0bc4da2b9fca0f31cb94e5aed.1589557526.git.lukas@wunner.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-05-20 15:16:11 +01:00
Lukas Wunner
84855678ad
spi: Fix controller unregister order
When an SPI controller unregisters, it unbinds all its slave devices.
For this, their drivers may need to access the SPI bus, e.g. to quiesce
interrupts.

However since commit ffbbdd2132 ("spi: create a message queueing
infrastructure"), spi_destroy_queue() is executed before unbinding the
slaves.  It sets ctlr->running = false, thereby preventing SPI bus
access and causing unbinding of slave devices to fail.

Fix by unbinding slaves before calling spi_destroy_queue().

Fixes: ffbbdd2132 ("spi: create a message queueing infrastructure")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org # v3.4+
Cc: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/8aaf9d44c153fe233b17bc2dec4eb679898d7e7b.1589557526.git.lukas@wunner.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-05-20 15:16:10 +01:00
Florian Fainelli
0392727c26
spi: bcm-qspi: Handle clock probe deferral
The clock provider may not be ready by the time spi-bcm-qspi gets
probed, handle probe deferral using devm_clk_get_optional().

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200420190853.45614-2-kdasu.kdev@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-04-21 16:05:57 +01:00
Justin Chen
4df3bea7f9
spi: bcm-qspi: when tx/rx buffer is NULL set to 0
Currently we set the tx/rx buffer to 0xff when NULL. This causes
problems with some spi slaves where 0xff is a valid command. Looking
at other drivers, the tx/rx buffer is usually set to 0x00 when NULL.
Following this convention solves the issue.

Fixes: fa236a7ef2 ("spi: bcm-qspi: Add Broadcom MSPI driver")
Signed-off-by: Justin Chen <justinpopo6@gmail.com>
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200420190853.45614-6-kdasu.kdev@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-04-21 16:05:56 +01:00
Kamal Dasu
1b7ad8c405
spi: bcm-qspi: Make PM suspend/resume work with SCMI clock management
SCMI only passes clk_prepare_enable() and clk_disable_unprepare(), made
changes to suspend/resume ops to use the appropriate calls so that PM
works for ARM and ARM64 platforms.

Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Link: https://lore.kernel.org/r/20200420190853.45614-7-kdasu.kdev@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-04-21 16:05:55 +01:00
Kamal Dasu
742d595806
spi: bcm-qspi: Drive MSPI peripheral SSb pin on cs_change
As per the spi core implementation for MSPI devices when the transfer is
the last one in the message, the chip may stay selected until the next
transfer. On multi-device SPI busses with nothing blocking messages going
to other devices, this is just a performance hint; starting a message to
another device deselects this one. But in other cases, this can be used
to ensure correctness. Some devices need protocol transactions to be built
from a series of spi_message submissions, where the content of one message
is determined by the results of previous messages and where the whole
transaction ends when the chipselect goes intactive.

On CS change after completing the last serial transfer, the MSPI driver
drives SSb pin CDRAM register correctly according comments in core spi.h
as shown below:

case 1) EOM =1, cs_change =0: SSb inactive
case 2) EOM =1, cs_change =1: SSb active
case 3) EOM =0, cs_change =0: SSb active
case 4) EOM =0, cs_change =1: SSb inactive

Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Link: https://lore.kernel.org/r/20200420190853.45614-5-kdasu.kdev@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-04-21 16:05:54 +01:00
Andy Shevchenko
0dadde344d
spi: Respect DataBitLength field of SpiSerialBusV2() ACPI resource
By unknown reason the commit 64bee4d28c
  ("spi / ACPI: add ACPI enumeration support")
missed the DataBitLength property to encounter when parse SPI slave
device data from ACPI.

Fill the gap here.

Fixes: 64bee4d28c ("spi / ACPI: add ACPI enumeration support")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200413180406.1826-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-04-14 12:39:38 +01:00
Christophe JAILLET
6d75145bf6
spi: sc18is602: Fix a typo in MODULE_DESCRIPTION
This should be 'SC18IS602', not 'SC18IC602'

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/20200413154043.23064-1-christophe.jaillet@wanadoo.fr
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-04-14 12:39:37 +01:00
Rafał Hibner
d103729a62
spi: spi-axi-spi-engine: Access register after clock initialization
Move register access after clock initialization.
Clock "s_axi_aclk" is needed for register access. Without the clock running
AXI bus hangs and causes kernel freeze.

Signed-off-by: Rafał Hibner <rafal.hibner@secom.com.pl>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Cc: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20200409155621.12174-1-rafal.hibner@secom.com.pl
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-04-09 18:46:53 +01:00
Jungseung Lee
61249ce08e
spi: spi-ep93xx: fix wrong SPI mode selection
The mode bits on control register 0 are in a different order compared
to the spi mode define values. Thus, in the current code, it fails to
set the correct SPI mode selection. Fix it.

Signed-off-by: Jungseung Lee <js07.lee@samsung.com>
Link: https://lore.kernel.org/r/20200402121022.9976-1-js07.lee@samsung.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-04-03 14:55:55 +01:00
Linus Walleij
ebb3b9a92b
spi: efm32: Convert to use GPIO descriptors
This switches the EFM32 driver over to use the GPIO descriptor
handling in the core. The GPIO handling in this driver is
pretty simplistic so this should just work. Drop the GPIO headers
and insert the implicitly included <linux/of.h> header.

Signed-off-by: Linus Walleij <linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Cc: Uwe Kleine-König <u.kleine-koenig-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
Link: https://lore.kernel.org/r/20200317094914.331932-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-27 15:52:23 +00:00
Gustavo A. R. Silva
6960b0332c
spi: spi-fsl-lpspi: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200320232515.GA24800@embeddedor.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-23 18:37:07 +00:00
Gustavo A. R. Silva
2d4ccc2ac6
spi: spi-s3c24xx: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Andi Shyti <andi@etezian.org>
Link: https://lore.kernel.org/r/20200320232556.GA24989@embeddedor.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-23 18:37:06 +00:00
Alain Volmat
1c52be8bed
spi: stm32: Fix comments compilation warnings
Fix all functions and structure descriptions to have the driver
warning free when built with W=1.

Signed-off-by: Alain Volmat <alain.volmat@st.com>
Reviewed-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/1584711857-9162-1-git-send-email-alain.volmat@st.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-20 21:01:40 +00:00
Tudor Ambarus
c528ecfbef
spi: atmel-quadspi: Add verbose debug facilities to monitor register accesses
This feature should not be enabled in release but can be useful for
developers who need to monitor register accesses at some specific places.

Helped me identify a bug in u-boot, by comparing the register accesses
from the linux driver with the ones from its u-boot variant.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20200320065058.891221-1-tudor.ambarus@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-20 13:03:38 +00:00
Vladimir Oltean
138f56ef91
spi: spi-fsl-dspi: Add support for LS1028A
This is similar to the DSPI instantiation on LS1028A, except that:
 - The A-011218 erratum has been fixed, so DMA works
 - The endianness is different, which has implications on XSPI mode

Some benchmarking with the following command:

spidev_test --device /dev/spidev2.0 --bpw 8 --size 256 --cpha --iter 10000000 --speed 20000000

shows that in DMA mode, it can achieve around 2400 kbps, and in XSPI
mode, the same command goes up to 4700 kbps. This is somewhat to be
expected, since the DMA buffer size is extremely small at 8 bytes, the
winner becomes whomever can prepare the buffers for transmission
quicker, and DMA mode has higher overhead there. So XSPI FIFO mode has
been chosen as the operating mode for this chip.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20200318001603.9650-11-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-18 22:45:01 +00:00
Vladimir Oltean
5b342c5ab7
spi: spi-fsl-dspi: Move invariant configs out of dspi_transfer_one_message
The operating mode (DMA, XSPI, EOQ) is not going to change across the
lifetime of the device. So it makes no sense to keep writing to SPI_RSER
on each message. Move this configuration to dspi_init instead.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20200318001603.9650-10-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-18 22:45:00 +00:00
Vladimir Oltean
826b3a6a34
spi: spi-fsl-dspi: Fix interrupt-less DMA mode taking an XSPI code path
Interrupts are not necessary for DMA functionality, since the completion
event is provided by the DMA driver.

But if the driver fails to request the IRQ defined in the device tree,
it will call dspi_poll which would make the driver hang waiting for data
to become available in the RX FIFO.

Fixes: c55be30591 ("spi: spi-fsl-dspi: Use poll mode in case the platform IRQ is missing")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20200318001603.9650-9-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-18 22:44:59 +00:00
Vladimir Oltean
3d6224e63b
spi: spi-fsl-dspi: Avoid NULL pointer in dspi_slave_abort for non-DMA mode
The driver does not create the dspi->dma structure unless operating in
DSPI_DMA_MODE, so it makes sense to check for that.

Fixes: f4b323905d ("spi: Introduce dspi_slave_abort() function for NXP's dspi SPI driver")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20200318001603.9650-8-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-18 22:44:58 +00:00
Vladimir Oltean
4f5ee75ea1
spi: spi-fsl-dspi: Replace interruptible wait queue with a simple completion
Currently the driver puts the process in interruptible sleep waiting for
the interrupt train to finish transfer to/from the tx_buf and rx_buf.

But exiting the process with ctrl-c may make the kernel panic: the
wait_event_interruptible call will return -ERESTARTSYS, which a proper
driver implementation is perhaps supposed to handle, but nonetheless
this one doesn't, and aborts the transfer altogether.

Actually when the task is interrupted, there is still a high chance that
the dspi_interrupt is still triggering. And if dspi_transfer_one_message
returns execution all the way to the spi_device driver, that can free
the spi_message and spi_transfer structures, leaving the interrupts to
access a freed tx_buf and rx_buf.

hexdump -C /dev/mtd0
00000000  00 75 68 75 0a ff ff ff  ff ff ff ff ff ff ff ff
|.uhu............|
00000010  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff
|................|
*
^C[   38.495955] fsl-dspi 2120000.spi: Waiting for transfer to complete failed!
[   38.503097] spi_master spi2: failed to transfer one message from queue
[   38.509729] Unable to handle kernel paging request at virtual address ffff800095ab3377
[   38.517676] Mem abort info:
[   38.520474]   ESR = 0x96000045
[   38.523533]   EC = 0x25: DABT (current EL), IL = 32 bits
[   38.528861]   SET = 0, FnV = 0
[   38.531921]   EA = 0, S1PTW = 0
[   38.535067] Data abort info:
[   38.537952]   ISV = 0, ISS = 0x00000045
[   38.541797]   CM = 0, WnR = 1
[   38.544771] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000082621000
[   38.551494] [ffff800095ab3377] pgd=00000020fffff003, p4d=00000020fffff003, pud=0000000000000000
[   38.560229] Internal error: Oops: 96000045 [#1] PREEMPT SMP
[   38.565819] Modules linked in:
[   38.568882] CPU: 0 PID: 2729 Comm: hexdump Not tainted 5.6.0-rc4-next-20200306-00052-gd8730cdc8a0b-dirty #193
[   38.578834] Hardware name: Kontron SMARC-sAL28 (Single PHY) on SMARC Eval 2.0 carrier (DT)
[   38.587129] pstate: 20000085 (nzCv daIf -PAN -UAO)
[   38.591941] pc : ktime_get_real_ts64+0x3c/0x110
[   38.596487] lr : spi_take_timestamp_pre+0x40/0x90
[   38.601203] sp : ffff800010003d90
[   38.604525] x29: ffff800010003d90 x28: ffff80001200e000
[   38.609854] x27: ffff800011da9000 x26: ffff002079c40400
[   38.615184] x25: ffff8000117fe018 x24: ffff800011daa1a0
[   38.620513] x23: ffff800015ab3860 x22: ffff800095ab3377
[   38.625841] x21: 000000000000146e x20: ffff8000120c3000
[   38.631170] x19: ffff0020795f6e80 x18: ffff800011da9948
[   38.636498] x17: 0000000000000000 x16: 0000000000000000
[   38.641826] x15: ffff800095ab3377 x14: 0720072007200720
[   38.647155] x13: 0720072007200765 x12: 0775076507750771
[   38.652483] x11: 0720076d076f0772 x10: 0000000000000040
[   38.657812] x9 : ffff8000108e2100 x8 : ffff800011dcabe8
[   38.663139] x7 : 0000000000000000 x6 : ffff800015ab3a60
[   38.668468] x5 : 0000000007200720 x4 : ffff800095ab3377
[   38.673796] x3 : 0000000000000000 x2 : 0000000000000ab0
[   38.679125] x1 : ffff800011daa000 x0 : 0000000000000026
[   38.684454] Call trace:
[   38.686905]  ktime_get_real_ts64+0x3c/0x110
[   38.691100]  spi_take_timestamp_pre+0x40/0x90
[   38.695470]  dspi_fifo_write+0x58/0x2c0
[   38.699315]  dspi_interrupt+0xbc/0xd0
[   38.702987]  __handle_irq_event_percpu+0x78/0x2c0
[   38.707706]  handle_irq_event_percpu+0x3c/0x90
[   38.712161]  handle_irq_event+0x4c/0xd0
[   38.716008]  handle_fasteoi_irq+0xbc/0x170
[   38.720115]  generic_handle_irq+0x2c/0x40
[   38.724135]  __handle_domain_irq+0x68/0xc0
[   38.728243]  gic_handle_irq+0xc8/0x160
[   38.732000]  el1_irq+0xb8/0x180
[   38.735149]  spi_nor_spimem_read_data+0xe0/0x140
[   38.739779]  spi_nor_read+0xc4/0x120
[   38.743364]  mtd_read_oob+0xa8/0xc0
[   38.746860]  mtd_read+0x4c/0x80
[   38.750007]  mtdchar_read+0x108/0x2a0
[   38.753679]  __vfs_read+0x20/0x50
[   38.757002]  vfs_read+0xa4/0x190
[   38.760237]  ksys_read+0x6c/0xf0
[   38.763471]  __arm64_sys_read+0x20/0x30
[   38.767319]  el0_svc_common.constprop.3+0x90/0x160
[   38.772125]  do_el0_svc+0x28/0x90
[   38.775449]  el0_sync_handler+0x118/0x190
[   38.779468]  el0_sync+0x140/0x180
[   38.782793] Code: 91000294 1400000f d50339bf f9405e80 (f90002c0)
[   38.788910] ---[ end trace 55da560db4d6bef7 ]---
[   38.793540] Kernel panic - not syncing: Fatal exception in interrupt
[   38.799914] SMP: stopping secondary CPUs
[   38.803849] Kernel Offset: disabled
[   38.807344] CPU features: 0x10002,20006008
[   38.811451] Memory Limit: none
[   38.814513] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

So it is clear that the "interruptible" part isn't handled correctly.
When the process receives a signal, one could either attempt a clean
abort (which appears to be difficult with this hardware) or just keep
restarting the sleep until the wait queue really completes. But checking
in a loop for -ERESTARTSYS is a bit too complicated for this driver, so
just make the sleep uninterruptible, to avoid all that nonsense.

The wait queue was actually restructured as a completion, after polling
other drivers for the most "popular" approach.

Fixes: 349ad66c0a ("spi:Add Freescale DSPI driver for Vybrid VF610 platform")
Reported-by: Michael Walle <michael@walle.cc>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20200318001603.9650-7-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-18 22:44:58 +00:00
Vladimir Oltean
0dedf90107
spi: spi-fsl-dspi: Protect against races on dspi->words_in_flight
dspi->words_in_flight is a variable populated in the *_write functions
and used in the dspi_fifo_read function. It is also used in
dspi_fifo_write, immediately after transmission, to update the
message->actual_length variable used by higher layers such as spi-mem
for integrity checking.

But it may happen that the IRQ which calls dspi_fifo_read to be
triggered before the updating of message->actual_length takes place. In
that case, dspi_fifo_read will decrement dspi->words_in_flight to -1,
and that will cause an invalid modification of message->actual_length.

For that, we make the simplest fix possible: to not decrement the actual
shared variable in dspi->words_in_flight from dspi_fifo_read, but
actually a copy of it which is on stack.

But even if dspi_fifo_read from the next IRQ does not interfere with the
dspi_fifo_write of the current chunk, the *next* dspi_fifo_write still
can. So we must assume that everything after the last write to the TX
FIFO can be preempted by the "TX complete" IRQ, and the dspi_fifo_write
function must be safe against that. This means refactoring the 2
flavours of FIFO writes (for EOQ and XSPI) such that the calculation of
the number of words to be written is common and happens a priori. This
way, the code for updating the message->actual_length variable works
with a copy and not with the volatile dspi->words_in_flight.

After some interior debate, the dspi->progress variable used for
software timestamping was *not* backed up against preemption in a copy
on stack. Because if preemption does occur between
spi_take_timestamp_pre and spi_take_timestamp_post, there's really no
point in trying to save anything. The first-in-time
spi_take_timestamp_post call with a dspi->progress higher than the
requested xfer->ptp_sts_word_post will trigger xfer->timestamped = true
anyway and will close the deal.

To understand the above a bit better, consider a transfer with
xfer->ptp_sts_word_pre = xfer->ptp_sts_word_post = 3, and
xfer->bits_per_words = 8 (so byte 3 needs to be timestamped). The DSPI
controller timestamps in chunks of 4 bytes at a time, and preemption
occurs in the middle of timestamping the first chunk:

  spi_take_timestamp_pre(0)
    .
    . (preemption)
    .
    . spi_take_timestamp_pre(4)
    .
    . spi_take_timestamp_post(7)
    .
  spi_take_timestamp_post(3)

So the reason I'm not bothering to back up dspi->progress for that
spi_take_timestamp_post(3) is that spi_take_timestamp_post(7) is going
to (a) be more honest, (b) provide better accuracy and (c) already
render the spi_take_timestamp_post(3) into a noop by setting
xfer->timestamped = true anyway.

Fixes: d59c90a240 ("spi: spi-fsl-dspi: Convert TCFQ users to XSPI FIFO mode")
Reported-by: Michael Walle <michael@walle.cc>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20200318001603.9650-6-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-18 22:44:57 +00:00
Vladimir Oltean
c6c1e30a78
spi: spi-fsl-dspi: Avoid reading more data than written in EOQ mode
If dspi->words_in_flight is populated with the hardware FIFO size,
then in dspi_fifo_read it will attempt to read more data at the end of a
buffer that is not a multiple of 16 bytes in length. It will probably
time out attempting to do so.

So limit the num_fifo_entries variable to the actual number of FIFO
entries that is going to be used.

Fixes: d59c90a240 ("spi: spi-fsl-dspi: Convert TCFQ users to XSPI FIFO mode")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20200318001603.9650-5-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-18 22:44:56 +00:00
Vladimir Oltean
a957499bd4
spi: spi-fsl-dspi: Fix bits-per-word acceleration in DMA mode
In DMA mode, dspi_setup_accel does not get called, which results in the
dspi->oper_word_size variable (which is used by dspi_dma_xfer) to not be
initialized properly.

Because oper_word_size is zero, a few calculations end up being
incorrect, and the DMA transfer eventually times out instead of sending
anything on the wire.

Set up native transfers (or 8-on-16 acceleration) using dspi_setup_accel
for DMA mode too.

Also take the opportunity and simplify the DMA buffer handling a little
bit.

Fixes: 6c1c26ecd9 ("spi: spi-fsl-dspi: Accelerate transfers using larger word size if possible")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20200318001603.9650-4-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-18 22:44:55 +00:00
Vladimir Oltean
671ffde175
spi: spi-fsl-dspi: Fix little endian access to PUSHR CMD and TXDATA
In XSPI mode, the 32-bit PUSHR register can be written to separately:
the higher 16 bits are for commands and the lower 16 bits are for data.

This has nicely been hacked around, by defining a second regmap with a
width of 16 bits, and effectively splitting a 32-bit register into 2
16-bit ones, from the perspective of this regmap_pushr.

The problem is the assumption about the controller's endianness. If the
controller is little endian (such as anything post-LS1046A), then the
first 2 bytes, in the order imposed by memory layout, will actually hold
the TXDATA, and the last 2 bytes will hold the CMD.

So take the controller's endianness into account when performing split
writes to PUSHR. The obvious and simple solution would have been to call
regmap_get_val_endian(), but that is an internal regmap function and we
don't want to change regmap just for this. Therefore, we just re-read
the "big-endian" device tree property.

Fixes: 58ba07ec79 ("spi: spi-fsl-dspi: Add support for XSPI mode registers")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20200318001603.9650-3-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-18 22:44:54 +00:00
Vladimir Oltean
4fcc7c2292
spi: spi-fsl-dspi: Don't access reserved fields in SPI_MCR
The SPI_MCR_PCSIS macro assumes that the controller has a number of chip
select signals equal to 6. That is not always the case, but actually is
described through the driver-specific "spi-num-chipselects" device tree
binding. LS1028A for example only has 4 chip selects.

Don't write to the upper bits of the PCSIS field, which are reserved in
the reference manual.

Fixes: 349ad66c0a ("spi:Add Freescale DSPI driver for Vybrid VF610 platform")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20200318001603.9650-2-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-18 22:44:53 +00:00
Linus Walleij
85dadb718c
spi: mxs: Drop GPIO includes
This driver is not using any symbols from the GPIO .h files
so drop them.

It was however implicitly using <linux/pinctrl/consumer.h>
so include that instead.

Cc: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20200317092457.264055-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-17 13:20:16 +00:00
Mark Brown
7315608302
Merge series "spi: meson-spicc: add support for AXG and G12A variants" from Neil Armstrong <narmstrong@baylibre.com>:
The SPICC controller in Amlogic AXG & G12A is capable of driving the
CLK/MOSI/SS signal lines through the idle state which avoid the signals
floating in unexpected state, is capable of using linear clock divider
to reach a much fine tuned range of clocks, while the old controller only
uses a power of two clock divider, result at a more coarse clock range and
finally is capable of running at 80M clock.

The SPICC controller in Amlogic G12A takes the source clock from a specific
clock instead of the bus clock and has a different FIFO size and doesn't
handle the RX Half interrupt the same way as GXL & AXG variants. Thus
the burst management is simplified and takes in account a variable FIFO
size.

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.

Neil Armstrong (7):
  spi: meson-spicc: remove unused variables
  spi: meson-spicc: support max 80MHz clock
  spi: meson-spicc: add min sclk for each compatible
  spi: meson-spicc: setup IO line delay
  spi: meson-spicc: adapt burst handling for G12A support
  dt-bindings: spi: amlogic,meson-gx-spicc: add Amlogic G12A compatible
  spi: meson-spicc: add support for Amlogic G12A

Sunny Luo (2):
  spi: meson-spicc: enhance output enable feature
  spi: meson-spicc: add a linear clock divider support

 .../bindings/spi/amlogic,meson-gx-spicc.yaml  |  22 +
 drivers/spi/Kconfig                           |   1 +
 drivers/spi/spi-meson-spicc.c                 | 496 +++++++++++++-----
 3 files changed, 392 insertions(+), 127 deletions(-)

--
2.22.0

_______________________________________________
linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic
2020-03-12 17:38:42 +00:00
Wolfram Sang
5b16668e63
spi: acpi: remove superfluous parameter check
to_spi_device() already checks 'dev'. No need to do it before calling
it.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/20200312134507.10000-1-wsa@the-dreams.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-12 17:38:41 +00:00
Neil Armstrong
4e3d322058
spi: meson-spicc: add support for Amlogic G12A
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>
2020-03-12 17:22:55 +00:00
Neil Armstrong
0eb707ac7d
spi: meson-spicc: adapt burst handling for G12A support
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>
2020-03-12 17:22:54 +00:00
Neil Armstrong
f27bff479e
spi: meson-spicc: setup IO line delay
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>
2020-03-12 17:22:53 +00:00
Neil Armstrong
8791068dab
spi: meson-spicc: add min sclk for each compatible
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>
2020-03-12 17:22:53 +00:00
Neil Armstrong
3196816ff6
spi: meson-spicc: support max 80MHz clock
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>
2020-03-12 17:22:52 +00:00
Sunny Luo
3e0cf4d3fc
spi: meson-spicc: add a linear clock divider support
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>
2020-03-12 17:22:51 +00:00
Sunny Luo
a6cda1f905
spi: meson-spicc: enhance output enable feature
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>
2020-03-12 17:22:50 +00:00
Neil Armstrong
b9dfb20eed
spi: meson-spicc: remove unused variables
Remove unused variables from spicc data struct.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20200312133131.26430-2-narmstrong@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-12 17:22:49 +00:00
Dan Carpenter
1a421ebab6
spi: spi-nxp-fspi: Fix a NULL vs IS_ERR() check in probe
The platform_get_resource_byname() function returns NULL on error, it
doesn't return error pointers.

Fixes: d166a73503 ("spi: fspi: dynamically alloc AHB memory")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20200312113154.GC20562@mwanda
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-12 15:09:58 +00:00
Mark Brown
b562b304ef spi: Rewrite mtk-quadspi spi-nor driver with spi-mem
This patchset from Chuanhong Guo <gch981213@gmail.com> adds a spi-mem
 driver for Mediatek SPI-NOR controller, which already has limited
 support by mtk-quadspi. This new driver can make use of full quadspi
 capability of this controller.
 -----BEGIN PGP SIGNATURE-----
 
 iQFHBAABCgAxFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAl5pQmYTHGJyb29uaWVA
 a2VybmVsLm9yZwAKCRAk1otyXVSH0D9sB/9PBy5hYIWLJOqP3Tegy+si7eEjgYQe
 32DvHZRYYL+Oc8OQMGnJYUY5grfriS300TjxeB4MNx8ajVyuaH7e2aIhgTz3oJ6a
 YrygFcxEi0LmRT82HyLVxptyblMSo3A8QWOTOqe1aFvJRZjDDKvEIcGCW2RPmtxT
 r/EoVVkSv4X+k3GUtYnRBrq12hL+vr1YIjZM05MVu2sDtFXLO2+wotFIODDv15zi
 ByBtwhKumKawUOETzGDw4EDV5MJx9nZtswRC4x3hDrLS6au39F/MyP78gpHm8vw+
 YfiS5/39rkB6j1QltcP3B9n7joxrgaFAYsLBTZUoE3IjeVTggcKCOSVX
 =q5ml
 -----END PGP SIGNATURE-----
gpgsig -----BEGIN PGP SIGNATURE-----
 
 iQFHBAABCgAxFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAl5pQt4THGJyb29uaWVA
 a2VybmVsLm9yZwAKCRAk1otyXVSH0BFqB/9jBg5bNy9mNXljELZ7RKCtbn9CThYk
 NvccckUJnjaTxSccGcGEetfFtoVvM4IJ8ffiL6gBrNDgvuSbedLkboqlftRRbkE2
 tvxnfjKGeiVIHXcXG0kzrVMDPPncYy+o8nQMJ8b/v+VFeLah6LCo0nT4t54LPvfZ
 52Nncdr8jAnjoet7t2CX2nJrhTOPUGhC7HxbwOyu2HOOd5nWmYAdT4UZo4Vdv1g9
 L1knLoZctpvCpql/mUWdOAqQbD0bD0vT3FKQaq6C6kAeE+kMWSGdPgYxyFdBEVXi
 uOmaqU7lHt2bsr6TRbOpw4ON0PzQtzZ/YhW2XEPJd6uc3GWy//qEyqgO
 =qoqi
 -----END PGP SIGNATURE-----

Merge tag 'mtk-mtd-spi-move' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-5.7

spi: Rewrite mtk-quadspi spi-nor driver with spi-mem

This patchset from Chuanhong Guo <gch981213@gmail.com> adds a spi-mem
driver for Mediatek SPI-NOR controller, which already has limited
support by mtk-quadspi. This new driver can make use of full quadspi
capability of this controller.
2020-03-11 19:58:20 +00:00
Chuanhong Guo
881d1ee9fe
spi: add support for mediatek spi-nor controller
This is a driver for mtk spi-nor controller using spi-mem interface.
The same controller already has limited support provided by mtk-quadspi
driver under spi-nor framework and this new driver is a replacement
for the old one.

Comparing to the old driver, this driver has following advantages:
1. It can handle any full-duplex spi transfer up to 6 bytes, and
   this is implemented using generic spi interface.
2. It take account into command opcode properly. The reading routine
   in this controller can only use 0x03 or 0x0b as opcode on 1-1-1
   transfers, but old driver doesn't implement this properly. This
   driver checks supported opcode explicitly and use (1) to perform
   unmatched operations.
3. It properly handles SFDP reading. Old driver can't read SFDP
   due to the bug mentioned in (2).
4. It can do 1-2-2 and 1-4-4 fast reading on spi-nor. These two ops
   requires parsing SFDP, which isn't possible in old driver. And
   the old driver is only flagged to support 1-1-2 mode.
5. It takes advantage of the DMA feature in this controller for
   long reads and supports IRQ on DMA requests to free cpu cycles
   from polling status registers on long DMA reading. It achieves
   up to 17.5MB/s reading speed (1-4-4 mode) which is way faster
   than the old one. IRQ is implemented as optional to maintain
   backward compatibility.

Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
Link: https://lore.kernel.org/r/20200306085052.28258-3-gch981213@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-11 19:56:07 +00:00
Chuanhong Guo
671c3bf50a
spi: make spi-max-frequency optional
We only need a spi-max-frequency when we specifically request a
spi frequency lower than the max speed of spi host.
This property is already documented as optional property and current
host drivers are implemented to operate at highest speed possible
when spi->max_speed_hz is 0.
This patch makes spi-max-frequency an optional property so that
we could just omit it to use max controller speed.

Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
Link: https://lore.kernel.org/r/20200306085052.28258-2-gch981213@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-11 19:56:06 +00:00
John Garry
caef2df113
spi: Stop selecting MTD_SPI_NOR for SPI_HISI_SFC_V3XX
By selecting MTD_SPI_NOR for SPI_HISI_SFC_V3XX, we may introduce unmet
dependencies:

WARNING: unmet direct dependencies detected for MTD_SPI_NOR
  Depends on [m]: MTD [=m] && SPI_MASTER [=y]
  Selected by [y]:
  - SPI_HISI_SFC_V3XX [=y] && SPI [=y] && SPI_MASTER [=y] && (ARM64 && ACPI [=y] || COMPILE_TEST [=y]) && HAS_IOMEM [=y]

Since MTD_SPI_NOR is only selected by SPI_HISI_SFC_V3XX for practical
reasons - slave devices use the spi-nor driver, enabled by MTD_SPI_NOR -
just drop it.

Signed-off-by: John Garry <john.garry@huawei.com>

Link: https://lore.kernel.org/r/1583948115-239907-1-git-send-email-john.garry@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-11 18:35:21 +00:00
Michael Walle
22ee9de1ec
spi: spi-fsl-dspi: fix DMA mapping
Use the correct device to request the DMA mapping. Otherwise the IOMMU
doesn't get the mapping and it will generate a page fault.

The error messages look like:
[    3.008452] arm-smmu 5000000.iommu: Unhandled context fault: fsr=0x402, iova=0xf9800000, fsynr=0x3f0022, cbfrsynra=0x828, cb=8
[    3.020123] arm-smmu 5000000.iommu: Unhandled context fault: fsr=0x402, iova=0xf9800000, fsynr=0x3f0022, cbfrsynra=0x828, cb=8

This was tested on a custom board with a LS1028A SoC.

Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20200310073313.21277-1-michael@walle.cc
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-10 18:34:57 +00:00
Mark Brown
36098a1db7
Merge series "spi: Add FSI-attached SPI controller driver" from Eddie James <eajames@linux.ibm.com>:
This series adds a dts binding and a driver for a new SPI controller that is
accessed over FSI bus.

Eddie James (2):
  dt-bindings: fsi: Add FSI2SPI bindings
  spi: Add FSI-attached SPI controller driver

 .../devicetree/bindings/fsi/ibm,fsi2spi.yaml  |  36 ++
 MAINTAINERS                                   |   7 +
 drivers/spi/Kconfig                           |   7 +
 drivers/spi/Makefile                          |   1 +
 drivers/spi/spi-fsi.c                         | 558 ++++++++++++++++++
 5 files changed, 609 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/fsi/ibm,fsi2spi.yaml
 create mode 100644 drivers/spi/spi-fsi.c

--
2.24.0
2020-03-10 14:30:58 +00:00
Geert Uytterhoeven
f3a14a3a4d
spi: rspi: Add support for active-high chip selects
All RSPI variants support setting the polarity of the SSL signal.
Advertize support for active-high chip selects, and configure polarity
according to the state of the flag.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200309171537.21551-1-geert+renesas@glider.be
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-10 14:30:56 +00:00
Johan Jonker
c6486eadb4
spi: rockchip: add compatible string for px30 rk3308 rk3328
The Rockchip spi binding is updated to yaml and new models
were added. The spi on px30,rk3308 and rk3328 are the same as
other Rockchip based SoCs, so add compatible string for it.

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Link: https://lore.kernel.org/r/20200309151004.7780-1-jbx6244@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-10 14:30:56 +00:00
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
Joe Perches
e14572c525
spi: Remove CONFIG_ prefix from Kconfig select
commit a2ca53b52e ("spi: Add HiSilicon v3xx SPI NOR flash
controller driver") likely inadvertently used a select statement
with a CONFIG_ prefix, remove the prefix.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/f8ac6b32a29b9a05b58a7e58ffe8b780642abbf1.camel@perches.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-06 15:19:16 +00:00
Mark Brown
4a8ee2ab49
Merge series "TCFQ to XSPI migration for NXP DSPI driver" from Vladimir Oltean <olteanv@gmail.com>
Vladimir Oltean <vladimir.oltean@nxp.com>:

From: Vladimir Oltean <vladimir.oltean@nxp.com>

This series aims to remove the most inefficient transfer method from the
NXP DSPI driver.

TCFQ (Transfer Complete Flag) mode works by transferring one word,
waiting for its TX confirmation interrupt (or polling on the equivalent
status bit), sending the next word, etc, until the buffer is complete.

The issue with this mode is that it's fundamentally incompatible with
any sort of batching such as writing to a FIFO. But actually, due to
previous patchset ("Compatible string consolidation for NXP DSPI driver"):

https://patchwork.kernel.org/cover/11414593/

all existing users of TCFQ mode today already support a more advanced
feature set, in the form of XSPI (extended SPI). XSPI brings 2 extra
features:

- Word sizes up to 32 bits. This is sub-utilized today, and acceleration
  of smaller-than-32 bpw values is provided.
- "Command cycling", basically the ability to write multiple words in a
  row and receiving an interrupt only after the completion of the last
  one. This is what enables us to make use of the full FIFO depth of
  this controller.

Series was tested on the NXP LS1021A-TSN and LS1043A-RDB boards, both
functionally as well as from a performance standpoint.

The command used to benchmark the increased throughput was:

spidev_test --device /dev/spidev1.0 --bpw 8 --size 256 --cpha --iter 10000000 --speed 20000000

where spidev1.0 is a dummy spidev node, using a chip select that no
peripheral responds to.

On LS1021A, which has a 4-entry-deep FIFO and a less powerful CPU, the
performance increase brought by this patchset is from 2700 kbps to 5800
kbps.

On LS1043A, which has a 16-entry-deep FIFO and a more powerful CPU, the
performance increases from 4100 kbps to 13700 kbps.

On average, SPI software timestamping is not adversely affected by the
extra batching, due to the extra patches.

There is one extra patch which clarifies why the TCFQ users were not
converted to the "other" mode in this driver that makes use of the FIFO,
which would be EOQ mode.

My request to the many people on CC (known users and/or contributors) is
to give this series a test to ensure there are no regressions, and for
the Coldfire maintainers to clarify whether the EOQ limitation is
acceptable for them in the long run.

Vladimir Oltean (12):
  spi: spi-fsl-dspi: Simplify bytes_per_word gymnastics
  spi: spi-fsl-dspi: Remove unused chip->void_write_data
  spi: spi-fsl-dspi: Don't mask off undefined bits
  spi: spi-fsl-dspi: Add comments around dspi_pop_tx and dspi_push_rx
    functions
  spi: spi-fsl-dspi: Rename fifo_{read,write} and {tx,cmd}_fifo_write
  spi: spi-fsl-dspi: Implement .max_message_size method for EOQ mode
  spi: Do spi_take_timestamp_pre for as many times as necessary
  spi: spi-fsl-dspi: Convert TCFQ users to XSPI FIFO mode
  spi: spi-fsl-dspi: Accelerate transfers using larger word size if
    possible
  spi: spi-fsl-dspi: Optimize dspi_setup_accel for lowest interrupt
    count
  spi: spi-fsl-dspi: Use EOQ for last word in buffer even for XSPI mode
  spi: spi-fsl-dspi: Take software timestamp in dspi_fifo_write

 drivers/spi/spi-fsl-dspi.c | 421 ++++++++++++++++++++++++-------------
 drivers/spi/spi.c          |  19 +-
 include/linux/spi/spi.h    |   3 +-
 3 files changed, 288 insertions(+), 155 deletions(-)

--
2.17.1
2020-03-05 14:36:28 +00:00
Sascha Hauer
29d2daf2c3
spi: spi-fsl-dspi: Make bus-num property optional
The SPI bus number is completely optional to Linux, so make the
corresponding device tree property optional as well.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Link: https://lore.kernel.org/r/20200305115546.31814-1-s.hauer@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-05 14:36:25 +00:00
Han Xu
b7461fa5be
spi: spi-nxp-fspi: Enable the Octal Mode in MCR0
Apply patch from NXP upstream repo to
Enable the octal combination mode in MCR0

Signed-off-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Han Xu <han.xu@nxp.com>

Link: https://lore.kernel.org/r/20200126140913.2139260-3-aford173@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-05 14:36:23 +00:00