Commit graph

236 commits

Author SHA1 Message Date
David Jander
95c8222f0e
spi: spi.c: Fix comment style
Capitalize first word in comment where appropriate and add
parentheses to function names.

Reported-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: David Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220629142519.3985486-3-david@protonic.nl
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-06-30 13:40:35 +01:00
David Jander
dc3029056b
spi: opportunistically skip ctlr->cur_msg_completion
There are only a few drivers that do not call
spi_finalize_current_message() in the context of transfer_one_message(),
and even for those cases the completion ctlr->cur_msg_completion is not
needed always. The calls to complete() and wait_for_completion() each
take a spin-lock, which is costly. This patch makes it possible to avoid
those calls in the big majority of cases, by introducing two flags that
with the help of ordering via barriers can avoid using the completion
safely. In case of a race with the context calling
spi_finalize_current_message(), the scheme errs on the safe side and takes
the completion.
The impact of this patch is worth the effort: On a i.MX8MM SoC, the time
the SPI bus is idle between two consecutive calls to spi_sync(), is
reduced from 19.6us to 16.8us... roughly 15%.

Signed-off-by: David Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220621061234.3626638-12-david@protonic.nl
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-06-27 13:27:26 +01:00
David Jander
69fa95905d
spi: Ensure the io_mutex is held until spi_finalize_current_message()
This patch introduces a completion that is completed in
spi_finalize_current_message() and waited for in
__spi_pump_transfer_message(). This way all manipulation of ctlr->cur_msg
is done with the io_mutex held and strictly ordered:
__spi_pump_transfer_message() will not return until
spi_finalize_current_message() is done using ctlr->cur_msg, and its
calling context is only touching ctlr->cur_msg after returning.
Due to this, we can safely drop the spin-locks around ctlr->cur_msg.

Signed-off-by: David Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220621061234.3626638-11-david@protonic.nl
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-06-27 13:27:25 +01:00
David Jander
66a221593c
spi: Remove the now unused ctlr->idling flag
The ctlr->idling flag is never checked now, so we don't need to set it
either.

Signed-off-by: David Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220621061234.3626638-8-david@protonic.nl
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-06-27 13:27:22 +01:00
David Jander
ae7d2346dc
spi: Don't use the message queue if possible in spi_sync
The interaction with the controller message queue and its corresponding
auxiliary flags and variables requires the use of the queue_lock which is
costly. Since spi_sync will transfer the complete message anyway, and not
return until it is finished, there is no need to put the message into the
queue if the queue is empty. This can save a lot of overhead.

As an example of how significant this is, when using the MCP2518FD SPI CAN
controller on a i.MX8MM SoC, the time during which the interrupt line
stays active (during 3 relatively short spi_sync messages), is reduced
from 98us to 72us by this patch.

Signed-off-by: David Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220621061234.3626638-3-david@protonic.nl
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-06-27 13:27:17 +01:00
David Jander
1714582a3a
spi: Move ctlr->cur_msg_prepared to struct spi_message
This enables the possibility to transfer a message that is not at the
current tip of the async message queue.
This is in preparation of the next patch(es) which enable spi_sync messages
to skip the queue altogether.

Signed-off-by: David Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220621061234.3626638-2-david@protonic.nl
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-06-27 13:27:16 +01:00
David Jander
67b9d64139
spi: Fix per-cpu stats access on 32 bit systems
On 32 bit systems, the following kernel BUG is hit:

BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1
caller is debug_smp_processor_id+0x18/0x24
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc1-00001-g6ae0aec8a366 #181
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
Backtrace:
 dump_backtrace from show_stack+0x20/0x24
 r7:81024ffd r6:00000000 r5:81024ffd r4:60000013
 show_stack from dump_stack_lvl+0x60/0x78
 dump_stack_lvl from dump_stack+0x14/0x1c
 r7:81024ffd r6:80f652de r5:80bec180 r4:819a2500
 dump_stack from check_preemption_disabled+0xc8/0xf0
 check_preemption_disabled from debug_smp_processor_id+0x18/0x24
 r8:8119b7e0 r7:81205534 r6:819f5c00 r5:819f4c00 r4:c083d724
 debug_smp_processor_id from __spi_sync+0x78/0x220
 __spi_sync from spi_sync+0x34/0x4c
 r10:bb7bf4e0 r9:c083d724 r8:00000007 r7:81a068c0 r6:822a83c0 r5:c083d724
 r4:819f4c00
 spi_sync from spi_mem_exec_op+0x338/0x370
 r5:000000b4 r4:c083d910
 spi_mem_exec_op from spi_nor_read_id+0x98/0xdc
 r10:bb7bf4e0 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:82358040
 r4:819f7c40
 spi_nor_read_id from spi_nor_detect+0x38/0x114
 r7:82358040 r6:00000000 r5:819f7c40 r4:819f7c40
 spi_nor_detect from spi_nor_scan+0x11c/0xbec
 r10:bb7bf4e0 r9:00000000 r8:00000000 r7:c083da4c r6:00000000 r5:00010101
 r4:819f7c40
 spi_nor_scan from spi_nor_probe+0x10c/0x2d0
 r10:bb7bf4e0 r9:bb7bf4d0 r8:00000000 r7:819f4c00 r6:00000000 r5:00000000
 r4:819f7c40

per-cpu access needs to be guarded against preemption.

Fixes: 6598b91b5a ("spi: spi.c: Convert statistics to per-cpu u64_stats_t")
Reported-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David Jander <david@protonic.nl>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Link: https://lore.kernel.org/r/20220609121334.2984808-1-david@protonic.nl
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-06-10 13:33:17 +01:00
David Jander
5dfac65b62
spi: <linux/spi/spi.h>: Add missing documentation for struct members
Fixes these "make htmldocs" warnings:

include/linux/spi/spi.h:82: warning: Function parameter or member 'syncp' not described in 'spi_statistics'
include/linux/spi/spi.h:213: warning: Function parameter or member 'pcpu_statistics' not described in 'spi_device'
include/linux/spi/spi.h:676: warning: Function parameter or member 'pcpu_statistics' not described in 'spi_controller'

Fixes: 6598b91b5a ("spi: spi.c: Convert statistics to per-cpu u64_stats_t")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David Jander <david@protonic.nl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220608153309.2899565-1-david@protonic.nl
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-06-08 17:45:42 +01:00
David Jander
6598b91b5a
spi: spi.c: Convert statistics to per-cpu u64_stats_t
This change gives a dramatic performance improvement in the hot path,
since many costly spin_lock_irqsave() calls can be avoided.

On an i.MX8MM system with a MCP2518FD CAN controller connected via SPI,
the time the driver takes to handle interrupts, or in other words the time
the IRQ line of the CAN controller stays low is mainly dominated by the
time it takes to do 3 relatively short sync SPI transfers. The effect of
this patch is a reduction of this time from 136us down to only 98us.

Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220524091808.2269898-1-david@protonic.nl
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-06-06 12:41:31 +01:00
Julia Lawall
657f8bd88c
spi: fix typo in comment
Spelling mistake (triple letters) in comment.
Detected with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Link: https://lore.kernel.org/r/20220521111145.81697-13-Julia.Lawall@inria.fr
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-06-06 12:41:26 +01:00
Linus Torvalds
500a434fc5 Driver core changes for 5.19-rc1
Here is the set of driver core changes for 5.19-rc1.
 
 Note, I'm not really happy with this pull request as-is, see below for
 details, but overall this is all good for everything but a small set of
 systems, which we have a fix for already.
 
 Lots of tiny driver core changes and cleanups happened this cycle,
 but the two major things were:
 
 	- firmware_loader reorganization and additions including the
 	  ability to have XZ compressed firmware images and the ability
 	  for userspace to initiate the firmware load when it needs to,
 	  instead of being always initiated by the kernel. FPGA devices
 	  specifically want this ability to have their firmware changed
 	  over the lifetime of the system boot, and this allows them to
 	  work without having to come up with yet-another-custom-uapi
 	  interface for loading firmware for them.
 	- physical location support added to sysfs so that devices that
 	  know this information, can tell userspace where they are
 	  located in a common way.  Some ACPI devices already support
 	  this today, and more bus types should support this in the
 	  future.
 
 Smaller changes included:
 	- driver_override api cleanups and fixes
 	- error path cleanups and fixes
 	- get_abi script fixes
 	- deferred probe timeout changes.
 
 It's that last change that I'm the most worried about.  It has been
 reported to cause boot problems for a number of systems, and I have a
 tested patch series that resolves this issue.  But I didn't get it
 merged into my tree before 5.18-final came out, so it has not gotten any
 linux-next testing.
 
 I'll send the fixup patches (there are 2) as a follow-on series to this
 pull request if you want to take them directly, _OR_ I can just revert
 the probe timeout changes and they can wait for the next -rc1 merge
 cycle.  Given that the fixes are tested, and pretty simple, I'm leaning
 toward that choice.  Sorry this all came at the end of the merge window,
 I should have resolved this all 2 weeks ago, that's my fault as it was
 in the middle of some travel for me.
 
 All have been tested in linux-next for weeks, with no reported issues
 other than the above-mentioned boot time outs.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the set of driver core changes for 5.19-rc1.

  Lots of tiny driver core changes and cleanups happened this cycle, but
  the two major things are:

   - firmware_loader reorganization and additions including the ability
     to have XZ compressed firmware images and the ability for userspace
     to initiate the firmware load when it needs to, instead of being
     always initiated by the kernel. FPGA devices specifically want this
     ability to have their firmware changed over the lifetime of the
     system boot, and this allows them to work without having to come up
     with yet-another-custom-uapi interface for loading firmware for
     them.

   - physical location support added to sysfs so that devices that know
     this information, can tell userspace where they are located in a
     common way. Some ACPI devices already support this today, and more
     bus types should support this in the future.

  Smaller changes include:

   - driver_override api cleanups and fixes

   - error path cleanups and fixes

   - get_abi script fixes

   - deferred probe timeout changes.

  It's that last change that I'm the most worried about. It has been
  reported to cause boot problems for a number of systems, and I have a
  tested patch series that resolves this issue. But I didn't get it
  merged into my tree before 5.18-final came out, so it has not gotten
  any linux-next testing.

  I'll send the fixup patches (there are 2) as a follow-on series to this
  pull request.

  All have been tested in linux-next for weeks, with no reported issues
  other than the above-mentioned boot time-outs"

* tag 'driver-core-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (55 commits)
  driver core: fix deadlock in __device_attach
  kernfs: Separate kernfs_pr_cont_buf and rename_lock.
  topology: Remove unused cpu_cluster_mask()
  driver core: Extend deferred probe timeout on driver registration
  MAINTAINERS: add Russ Weight as a firmware loader maintainer
  driver: base: fix UAF when driver_attach failed
  test_firmware: fix end of loop test in upload_read_show()
  driver core: location: Add "back" as a possible output for panel
  driver core: location: Free struct acpi_pld_info *pld
  driver core: Add "*" wildcard support to driver_async_probe cmdline param
  driver core: location: Check for allocations failure
  arch_topology: Trace the update thermal pressure
  kernfs: Rename kernfs_put_open_node to kernfs_unlink_open_file.
  export: fix string handling of namespace in EXPORT_SYMBOL_NS
  rpmsg: use local 'dev' variable
  rpmsg: Fix calling device_lock() on non-initialized device
  firmware_loader: describe 'module' parameter of firmware_upload_register()
  firmware_loader: Move definitions from sysfs_upload.h to sysfs.h
  firmware_loader: Fix configs for sysfs split
  selftests: firmware: Add firmware upload selftests
  ...
2022-06-03 11:48:47 -07:00
Siddh Raman Pant
75d6fe48a2
spi: Doc fix - Describe add_lock and dma_map_dev in spi_controller
This fixes the corresponding warnings during building the docs.

Signed-off-by: Siddh Raman Pant <siddhpant.gh@gmail.com>
Link: https://lore.kernel.org/r/4e6187a4-d0f8-4750-e407-e09cc1c91789@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-05-12 15:43:04 +01:00
Krzysztof Kozlowski
19368f0f23 spi: Use helper for safer setting of driver_override
Use a helper to set driver_override to the reduce amount of duplicated
code.

Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220419113435.246203-8-krzysztof.kozlowski@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22 17:13:54 +02:00
Linus Torvalds
e35a4a4e13 Core MTD changes:
* Replace the expert mode symbols with a single helper
 * Fix misuses of of_match_ptr()
 * Remove partid and partname debugfs files
 * tests: Fix eraseblock read speed miscalculation for lower partition sizes
 * TRX parser: Allow to use on MediaTek MIPS SoCs
 
 MTD driver changes:
 * spear_smi: use GFP_KERNEL
 * mchp48l640: Add SPI ID table
 * mchp23k256: Add SPI ID table
 * blkdevs: Avoid soft lockups with some mtd/spi devices
 * aspeed-smc: Improve probe resilience
 
 Hyperbus changes:
 * HBMC_AM654 should depend on ARCH_K3
 
 NAND core changes:
 * ECC:
   - Add infrastructure to support hardware engines
   - Add a new helper to retrieve the ECC context
   - Provide a helper to retrieve a pilelined engine device
 
 NAND-ECC changes:
 * Macronix ECC engine:
   - Add Macronix external ECC engine support
   - Support SPI pipelined mode
   - Make two read-only arrays static const
   - Fix compile test issue
 
 Raw NAND core changes:
 * Fix misuses of of_match_node()
 * Rework of_get_nand_bus_width()
 * Remove of_get_nand_on_flash_bbt() wrapper
 * Protect access to rawnand devices while in suspend
 * bindings: Document the wp-gpios property
 
 Rax NAND controller driver changes:
 * atmel: Fix refcount issue in atmel_nand_controller_init
 * nandsim:
   - Add NS_PAGE_BYTE_SHIFT macro to replace the repeat pattern
   - Merge repeat codes in ns_switch_state
   - Replace overflow check with kzalloc to single kcalloc
 * rockchip: Fix platform_get_irq.cocci warning
 * stm32_fmc2: Add NAND Write Protect support
 * pl353: Set the nand chip node as the flash node
 * brcmnand: Fix sparse warnings in bcma_nand
 * omap_elm: Remove redundant variable 'errors'
 * gpmi:
   - Support fast edo timings for mx28
   - Validate controller clock rate
   - Fix controller timings setting
 * brcmnand:
   - Add BCMA shim
   - BCMA controller uses command shift of 0
   - Allow platform data instantation
   - Add platform data structure for BCMA
   - Allow working without interrupts
   - Move OF operations out of brcmnand_init_cs()
   - Avoid pdev in brcmnand_init_cs()
   - Allow SoC to provide I/O operations
   - Assign soc as early as possible
 
 Onenand changes:
 * Check for error irq
 
 SPI-NAND core changes:
 * Delay a little bit the dirmap creation
 * Create direct mapping descriptors for ECC operations
 
 SPI-NAND driver changes:
 * macronix: Use random program load
 
 SPI NOR core changes:
 * Move vendor specific code out of the core into vendor drivers.
 * Unify all function and object names in the vendor modules.
 * Make setup() callback optional to improve readability.
 * Skip erase logic when the SPI_NOR_NO_ERASE flag is set at flash
   declaration.
 
 SPI changes:
 * Macronix SPI controller:
   - Fix the transmit path
   - Create a helper to configure the controller before an operation
   - Create a helper to ease the start of an operation
   - Add support for direct mapping
   - Add support for pipelined ECC operations
 * spi-mem:
   - Introduce a capability structure
   - Check the controller extra capabilities
   - cadence-quadspi/mxic: Provide capability structures
   - Kill the spi_mem_dtr_supports_op() helper
   - Add an ecc parameter to the spi_mem_op structure
 
 Binding changes:
 * Dropped mtd/cortina,gemini-flash.txt
 * Convert BCM47xx partitions to json-schema
 * Vendor prefixes: Clarify Macronix prefix
 * SPI NAND: Convert spi-nand description file to yaml
 * Raw NAND chip: Create a NAND chip description
 * Raw NAND controller:
   - Harmonize the property types
   - Fix a comment in the examples
   - Fix the reg property description
 * Describe Macronix NAND ECC engine
 * Macronix SPI controller:
   - Document the nand-ecc-engine property
   - Convert to yaml
   - The interrupt property is not mandatory
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Merge tag 'mtd/changes-for-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux

Pull MTD updates from Miquel Raynal:
 "There has been a lot of activity in the MTD subsystem recently, with a
  number of SPI-NOR cleanups as well as the introduction of ECC engines
  that can be used by SPI controllers (hence a few SPI patches in here).

  Core MTD changes:
   - Replace the expert mode symbols with a single helper
   - Fix misuses of of_match_ptr()
   - Remove partid and partname debugfs files
   - tests: Fix eraseblock read speed miscalculation for lower partition
     sizes
   - TRX parser: Allow to use on MediaTek MIPS SoCs

  MTD driver changes:
   - spear_smi: use GFP_KERNEL
   - mchp48l640: Add SPI ID table
   - mchp23k256: Add SPI ID table
   - blkdevs: Avoid soft lockups with some mtd/spi devices
   - aspeed-smc: Improve probe resilience

  Hyperbus changes:
   - HBMC_AM654 should depend on ARCH_K3

  NAND core changes:
   - ECC:
      - Add infrastructure to support hardware engines
      - Add a new helper to retrieve the ECC context
      - Provide a helper to retrieve a pilelined engine device

  NAND-ECC changes:
   - Macronix ECC engine:
      - Add Macronix external ECC engine support
      - Support SPI pipelined mode
      - Make two read-only arrays static const
      - Fix compile test issue

  Raw NAND core changes:
   - Fix misuses of of_match_node()
   - Rework of_get_nand_bus_width()
   - Remove of_get_nand_on_flash_bbt() wrapper
   - Protect access to rawnand devices while in suspend
   - bindings: Document the wp-gpios property

  Rax NAND controller driver changes:
   - atmel: Fix refcount issue in atmel_nand_controller_init
   - nandsim:
      - Add NS_PAGE_BYTE_SHIFT macro to replace the repeat pattern
      - Merge repeat codes in ns_switch_state
      - Replace overflow check with kzalloc to single kcalloc
   - rockchip: Fix platform_get_irq.cocci warning
   - stm32_fmc2: Add NAND Write Protect support
   - pl353: Set the nand chip node as the flash node
   - brcmnand: Fix sparse warnings in bcma_nand
   - omap_elm: Remove redundant variable 'errors'
   - gpmi:
      - Support fast edo timings for mx28
      - Validate controller clock rate
      - Fix controller timings setting
   - brcmnand:
      - Add BCMA shim
      - BCMA controller uses command shift of 0
      - Allow platform data instantation
      - Add platform data structure for BCMA
      - Allow working without interrupts
      - Move OF operations out of brcmnand_init_cs()
      - Avoid pdev in brcmnand_init_cs()
      - Allow SoC to provide I/O operations
      - Assign soc as early as possible

  Onenand changes:
   - Check for error irq

  SPI-NAND core changes:
   - Delay a little bit the dirmap creation
   - Create direct mapping descriptors for ECC operations

  SPI-NAND driver changes:
   - macronix: Use random program load

  SPI NOR core changes:
   - Move vendor specific code out of the core into vendor drivers.
   - Unify all function and object names in the vendor modules.
   - Make setup() callback optional to improve readability.
   - Skip erase logic when the SPI_NOR_NO_ERASE flag is set at flash
     declaration.

  SPI changes:
   - Macronix SPI controller:
      - Fix the transmit path
      - Create a helper to configure the controller before an operation
      - Create a helper to ease the start of an operation
      - Add support for direct mapping
      - Add support for pipelined ECC operations
   - spi-mem:
      - Introduce a capability structure
      - Check the controller extra capabilities
      - cadence-quadspi/mxic: Provide capability structures
      - Kill the spi_mem_dtr_supports_op() helper
      - Add an ecc parameter to the spi_mem_op structure

  Binding changes:
   - Dropped mtd/cortina,gemini-flash.txt
   - Convert BCM47xx partitions to json-schema
   - Vendor prefixes: Clarify Macronix prefix
   - SPI NAND: Convert spi-nand description file to yaml
   - Raw NAND chip: Create a NAND chip description
   - Raw NAND controller:
      - Harmonize the property types
      - Fix a comment in the examples
      - Fix the reg property description
   - Describe Macronix NAND ECC engine
   - Macronix SPI controller:
      - Document the nand-ecc-engine property
      - Convert to yaml
      - The interrupt property is not mandatory"

* tag 'mtd/changes-for-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux: (104 commits)
  mtd: nand: ecc: mxic: Fix compile test issue
  mtd: nand: mxic-ecc: make two read-only arrays static const
  mtd: hyperbus: HBMC_AM654 should depend on ARCH_K3
  mtd: core: Remove partid and partname debugfs files
  dt-bindings: mtd: partitions: convert BCM47xx to the json-schema
  mtd: tests: Fix eraseblock read speed miscalculation for lower partition sizes
  mtd: rawnand: atmel: fix refcount issue in atmel_nand_controller_init
  mtd: rawnand: rockchip: fix platform_get_irq.cocci warning
  mtd: spi-nor: Skip erase logic when SPI_NOR_NO_ERASE is set
  mtd: spi-nor: renumber flags
  mtd: spi-nor: slightly change code style in spi_nor_sr_ready()
  mtd: spi-nor: spansion: rename vendor specific functions and defines
  mtd: spi-nor: spansion: convert USE_CLSR to a manufacturer flag
  mtd: spi-nor: move all spansion specifics into spansion.c
  mtd: spi-nor: spansion: slightly rework control flow in late_init()
  mtd: spi-nor: micron-st: rename vendor specific functions and defines
  mtd: spi-nor: micron-st: convert USE_FSR to a manufacturer flag
  mtd: spi-nor: move all micron-st specifics into micron-st.c
  mtd: spi-nor: xilinx: correct the debug message
  mtd: spi-nor: xilinx: rename vendor specific functions and defines
  ...
2022-03-25 13:35:34 -07:00
Yun Zhou
6bb477df04
spi: use specific last_cs instead of last_cs_enable
Commit d40f0b6f2e instroduced last_cs_enable to avoid setting
chipselect if it's not necessary, but it also introduces a bug. The
chipselect may not be set correctly on multi-device SPI busses. The
reason is that we can't judge the chipselect by bool last_cs_enable,
since chipselect may be modified after other devices were accessed.

So we should record the specific state of chipselect in case of
confusion.

Signed-off-by: Yun Zhou <yun.zhou@windriver.com>
Link: https://lore.kernel.org/r/20220217141234.72737-1-yun.zhou@windriver.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-02-28 13:36:16 +00:00
Linus Walleij
f48dc6b966
spi: Retire legacy GPIO handling
All drivers using GPIOs as chip select have been rewritten to use
GPIO descriptors passing the ->use_gpio_descriptors flag. Retire
the code and fields used by the legacy GPIO API.

Do not drop the ->use_gpio_descriptors flag: it now only indicates
that we want to use GPIOs in addition to native chip selects.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20220210231954.807904-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-02-14 12:53:18 +00:00
Miquel Raynal
4a3cc7fb6e spi: spi-mem: Introduce a capability structure
Create a spi_controller_mem_caps structure and put it within the
spi_controller structure close to the spi_controller_mem_ops
strucure. So far the only field in this structure is the support for dtr
operations, but soon we will add another parameter.

Also create a helper to parse the capabilities and check if the
requested capability has been set or not.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/linux-mtd/20220127091808.1043392-2-miquel.raynal@bootlin.com
2022-02-10 09:32:29 +01:00
Mark Brown
2cbfa21286
spi: make remove callback a void function
Merge series from Uwe Kleine-König <u.kleine-koenig@pengutronix.de>:

this series goal is to change the spi remove callback's return value to void.
After numerous patches nearly all drivers already return 0 unconditionally.
The four first patches in this series convert the remaining three drivers to
return 0, the final patch changes the remove prototype and converts all
implementers.

base-commit: 26291c54e1
2022-02-09 14:32:59 +00:00
Uwe Kleine-König
a0386bba70
spi: make remove callback a void function
The value returned by an spi driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Claudius Heine <ch@denx.de>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
Acked-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Acked-by: Łukasz Stelmach <l.stelmach@samsung.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220123175201.34839-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-02-09 13:00:45 +00:00
Stefan Binding
e612af7ace
spi: Add API to count spi acpi resources
Some ACPI nodes may have more than one Spi Resource.
To be able to handle these case, its necessary to have
a way of counting these resources.

Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220121172431.6876-5-sbinding@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-02-01 17:38:48 +00:00
Stefan Binding
87e59b36e5
spi: Support selection of the index of the ACPI Spi Resource before alloc
If a node contains more than one SPI resource it may be necessary to
use an index to select which one you want to allocate a spi device for.

Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220121172431.6876-4-sbinding@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-02-01 17:38:47 +00:00
Stefan Binding
000bee0ed7
spi: Create helper API to lookup ACPI info for spi device
This can then be used to find a spi resource inside an
ACPI node, and allocate a spi device.

Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220121172431.6876-3-sbinding@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-02-01 17:38:46 +00:00
Stefan Binding
e3dc139950
spi: Make spi_alloc_device and spi_add_device public again
This functions were previously made private since they
were not used. However, these functions will be needed
again.

Partial revert of commit da21fde0fd
("spi: Make several public functions private to spi.c")

Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220121172431.6876-2-sbinding@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-02-01 17:38:45 +00:00
Jakub Kicinski
44ea62813f
spi: don't include ptp_clock_kernel.h in spi.h
Commit b42faeee71 ("spi: Add a PTP system timestamp
to the transfer structure") added an include of ptp_clock_kernel.h
to spi.h for struct ptp_system_timestamp but a forward declaration
is enough. Let's use that to limit the number of objects we have
to rebuild every time we touch networking headers.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20210904013140.2377609-1-kuba@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-01-07 17:14:30 +00:00
Mark Brown
531558b56b
Merge branch 'spi-5.15' into spi-5.16 2021-10-14 14:15:46 +01:00
Mark Brown
6098475d4c
spi: Fix deadlock when adding SPI controllers on SPI buses
Currently we have a global spi_add_lock which we take when adding new
devices so that we can check that we're not trying to reuse a chip
select that's already controlled.  This means that if the SPI device is
itself a SPI controller and triggers the instantiation of further SPI
devices we trigger a deadlock as we try to register and instantiate
those devices while in the process of doing so for the parent controller
and hence already holding the global spi_add_lock.  Since we only care
about concurrency within a single SPI bus move the lock to be per
controller, avoiding the deadlock.

This can be easily triggered in the case of spi-mux.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-10-14 12:47:29 +01:00
Uwe Kleine-König
da21fde0fd
spi: Make several public functions private to spi.c
All these functions have no callers apart from drivers/spi/spi.c. So
drop their declarations in include/linux/spi/spi.h and don't export
them.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211007121415.2401638-5-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-10-07 15:46:00 +01:00
Uwe Kleine-König
bdc7ca008e
spi: Remove unused function spi_busnum_to_master()
The last user is gone since commit

	2962db71c7 ("staging/fbtft: Remove fbtft_device")

in 2019.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211007121415.2401638-3-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-10-07 15:45:57 +01:00
Mason Zhang
04e6bb0d6b
spi: modify set_cs_timing parameter
This patch modified set_cs_timing parameter, no need pass in spi_delay
to set_cs_timing callback.
By the way, we modified the mediatek and tegra114 spi driver to fix build err.
In mediatek spi driver, We have support set absolute time not clk_count,
and call this function in prepare_message not user's API.

Signed-off-by: Mason Zhang <Mason.Zhang@mediatek.com>
Link: https://lore.kernel.org/r/20210804133746.6742-1-Mason.Zhang@mediatek.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-08-05 16:42:54 +01:00
Mason Zhang
8c33ebfeeb
spi: move cs spi_delay to spi_device
As we know, spi core layer has removed spi_set_cs_timing() API.
So this patch moved spi_delay for cs_timing from spi_controller
to spi_device, because cs timing should be set by spi_device but
not controller.

Signed-off-by: Mason Zhang <Mason.Zhang@mediatek.com>
Link: https://lore.kernel.org/r/20210804133716.32040-1-Mason.Zhang@mediatek.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-08-05 16:42:53 +01:00
Randy Dunlap
8dd591ad01
spi: <linux/spi/spi.h>: add missing struct kernel-doc entry
Fix kernel-doc warning in spi.h by adding the missing kernel-doc entry
and also correct the original comment so that they both indicate the
correct polarity of the flag.

../include/linux/spi/spi.h:673: warning: Function parameter or member 'devm_allocated' not described in 'spi_controller'

Fixes: 794aaf0144 ("spi: Fix use-after-free with devm_spi_alloc_*")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: William A. Kennington III <wak@google.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: linux-spi@vger.kernel.org
Cc: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/20210628210520.5712-1-rdunlap@infradead.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-07-11 23:51:44 +01:00
Vinod Koul
b470e10eb4
spi: core: add dma_map_dev for dma device
Some controllers like qcom geni need the parent device to be used for
dma mapping, so add a dma_map_dev field and let drivers fill this to be
used as mapping device

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20210625052213.32260-4-vkoul@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-06-25 12:26:49 +01:00
Sebastian Reichel
0c79378c01
spi: add ancillary device support
Introduce support for ancillary devices, similar to existing
implementation for I2C. This is useful for devices having
multiple chip-selects, for example some microcontrollers
provide a normal SPI interface and a flashing SPI interface.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20210621175359.126729-2-sebastian.reichel@collabora.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-06-22 12:54:59 +01:00
Greg Kroah-Hartman
4ccf359849
spi: remove spi_set_cs_timing()
No one seems to be using this global and exported function, so remove it
as it is no longer needed.

Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20210609071918.2852069-1-gregkh@linuxfoundation.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-06-09 11:55:46 +01:00
Andy Shevchenko
35f3f8504c
spi: Switch to signed types for *_native_cs SPI controller fields
While fixing undefined behaviour the commit f60d7270c8 ("spi: Avoid
undefined behaviour when counting unused native CSs") missed the case
when all CSs are GPIOs and thus unused_native_cs will be evaluated to
-1 in unsigned representation. This will falsely trigger a condition
in the spi_get_gpio_descs().

Switch to signed types for *_native_cs SPI controller fields to fix above.

Fixes: f60d7270c8 ("spi: Avoid undefined behaviour when counting unused native CSs")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210510131242.49455-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-05-11 10:05:40 +01:00
Mark Brown
c7ed5fd5fb
Merge branch 'for-5.12' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-5.13 2021-04-15 19:29:40 +01:00
William A. Kennington III
794aaf0144
spi: Fix use-after-free with devm_spi_alloc_*
We can't rely on the contents of the devres list during
spi_unregister_controller(), as the list is already torn down at the
time we perform devres_find() for devm_spi_release_controller. This
causes devices registered with devm_spi_alloc_{master,slave}() to be
mistakenly identified as legacy, non-devm managed devices and have their
reference counters decremented below 0.

------------[ cut here ]------------
WARNING: CPU: 1 PID: 660 at lib/refcount.c:28 refcount_warn_saturate+0x108/0x174
[<b0396f04>] (refcount_warn_saturate) from [<b03c56a4>] (kobject_put+0x90/0x98)
[<b03c5614>] (kobject_put) from [<b0447b4c>] (put_device+0x20/0x24)
 r4:b6700140
[<b0447b2c>] (put_device) from [<b07515e8>] (devm_spi_release_controller+0x3c/0x40)
[<b07515ac>] (devm_spi_release_controller) from [<b045343c>] (release_nodes+0x84/0xc4)
 r5:b6700180 r4:b6700100
[<b04533b8>] (release_nodes) from [<b0454160>] (devres_release_all+0x5c/0x60)
 r8:b1638c54 r7:b117ad94 r6:b1638c10 r5:b117ad94 r4:b163dc10
[<b0454104>] (devres_release_all) from [<b044e41c>] (__device_release_driver+0x144/0x1ec)
 r5:b117ad94 r4:b163dc10
[<b044e2d8>] (__device_release_driver) from [<b044f70c>] (device_driver_detach+0x84/0xa0)
 r9:00000000 r8:00000000 r7:b117ad94 r6:b163dc54 r5:b1638c10 r4:b163dc10
[<b044f688>] (device_driver_detach) from [<b044d274>] (unbind_store+0xe4/0xf8)

Instead, determine the devm allocation state as a flag on the
controller which is guaranteed to be stable during cleanup.

Fixes: 5e844cc37a ("spi: Introduce device-managed SPI controller allocation")
Signed-off-by: William A. Kennington III <wak@google.com>
Link: https://lore.kernel.org/r/20210407095527.2771582-1-wak@google.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-04-08 15:08:53 +01:00
Wan Jiabing
d6644a1c2e
spi: Remove repeated struct declaration
struct spi_transfer is declared twice. One is declared at 24th line.
The blew one is not needed though. Remove the duplicate.

Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Link: https://lore.kernel.org/r/20210401065904.994121-1-wanjiabing@vivo.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-04-01 12:19:45 +01:00
Mark Brown
4152c4d0d9
Merge series "spi: Adding support for software nodes" from Heikki Krogerus <heikki.krogerus@linux.intel.com>:
Hi,

The older API used to supply additional device properties for the
devices - so mainly the function device_add_properties() - is going to
be removed. The reason why the API will be removed is because it gives
false impression that the properties are assigned directly to the
devices, which has actually never been the case - the properties have
always been assigned to a software fwnode which was then just directly
linked with the device when the old API was used. By only accepting
device properties instead of complete software nodes, the subsystems
remove any change of taking advantage of the other features the
software nodes have.

The change that is required from the spi subsystem and the drivers is
trivial. Basically only the "properties" member in struct
spi_board_info, which was a pointer to struct property_entry, is
replaced with a pointer to a complete software node.

thanks,

Heikki Krogerus (4):
  spi: Add support for software nodes
  ARM: pxa: icontrol: Constify the software node
  ARM: pxa: zeus: Constify the software node
  spi: Remove support for dangling device properties

 arch/arm/mach-pxa/icontrol.c | 12 ++++++++----
 arch/arm/mach-pxa/zeus.c     |  6 +++++-
 drivers/spi/spi.c            | 21 ++++++---------------
 include/linux/spi/spi.h      |  7 +++----
 4 files changed, 22 insertions(+), 24 deletions(-)

--
2.30.1

base-commit: a38fd87484
2021-03-16 17:55:41 +00:00
Heikki Krogerus
df41a5dad5
spi: Remove support for dangling device properties
>From now on only accepting complete software nodes.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20210303152814.35070-5-heikki.krogerus@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-03-16 13:29:44 +00:00
Heikki Krogerus
47afc77bbf
spi: Add support for software nodes
Making it possible for the drivers to assign complete
software fwnodes to the devices instead of only the device
properties in those nodes.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20210303152814.35070-2-heikki.krogerus@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-03-16 13:29:41 +00:00
Alexandru Ardelean
3ab1cce553
spi: core: remove 'delay_usecs' field from spi_transfer
The 'delay' field in the spi_transfer struct is meant to replace the
'delay_usecs' field. However some cleanup was required to remove the
uses of 'delay_usecs'. Now that it's been cleaned up, we can remove it
from the kernel tree.

Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210308145502.1075689-10-aardelean@deviqon.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-03-12 14:30:50 +00:00
Bhaskar Chowdhury
883c36a32f
spi: Change provied to provided in the file spi.h
s/provied/provided/

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Link: https://lore.kernel.org/r/20210208114928.32241-1-unixbhaskar@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-02-08 11:56:37 +00:00
Sowjanya Komatineni
98621ed011
spi: spi-mem: Mark dummy transfers by setting dummy_data bit
This patch marks dummy transfer by setting dummy_data bit to 1.

Controllers supporting dummy transfer by hardware use this bit field
to skip software transfer of dummy bytes and use hardware dummy bytes
transfer.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Link: https://lore.kernel.org/r/1608585459-17250-6-git-send-email-skomatineni@nvidia.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-01-06 13:09:31 +00:00
Dragos Bogdan
d962608ce2
spi: Add SPI_NO_TX/RX support
Transmit/receive only is a valid SPI mode. For example, the MOSI/TX line
might be missing from an ADC while for a DAC the MISO/RX line may be
optional. This patch adds these two new modes: SPI_NO_TX and
SPI_NO_RX. This way, the drivers will be able to identify if any of
these two lines is missing and to adjust the transfers accordingly.

Signed-off-by: Dragos Bogdan <dragos.bogdan@analog.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20201221152936.53873-2-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-12-28 14:21:31 +00:00
Alexandru Ardelean
f7005142da
spi: uapi: unify SPI modes into a single spi.h header
This change moves all the SPI mode bits into a separate 'spi.h' header in
uAPI. This is meant to re-use these definitions inside the kernel as well
as export them to userspace (via uAPI).

The SPI mode definitions have usually been duplicated between between
'include/linux/spi/spi.h' and 'include/uapi/linux/spi/spidev.h', so
whenever adding a new entry, this would need to be put in both headers.

They've been moved from 'include/linux/spi/spi.h', since that seems a bit
more complete; the bits have descriptions and there is the SPI_MODE_X_MASK.

This change also does a conversion of these bitfields to _BITUL() macro.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20201221152936.53873-1-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-12-28 14:21:30 +00:00
Mark Brown
db4a831997
Merge branch 'for-5.10' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-5.11 2020-11-27 16:18:32 +00:00
Lukas Wunner
5e844cc37a
spi: Introduce device-managed SPI controller allocation
SPI driver probing currently comprises two steps, whereas removal
comprises only one step:

    spi_alloc_master()
    spi_register_controller()

    spi_unregister_controller()

That's because spi_unregister_controller() calls device_unregister()
instead of device_del(), thereby releasing the reference on the
spi_controller which was obtained by spi_alloc_master().

An SPI driver's private data is contained in the same memory allocation
as the spi_controller struct.  Thus, once spi_unregister_controller()
has been called, the private data is inaccessible.  But some drivers
need to access it after spi_unregister_controller() to perform further
teardown steps.

Introduce devm_spi_alloc_master() and devm_spi_alloc_slave(), which
release a reference on the spi_controller struct only after the driver
has unbound, thereby keeping the memory allocation accessible.  Change
spi_unregister_controller() to not release a reference if the
spi_controller was allocated by one of these new devm functions.

The present commit is small enough to be backportable to stable.
It allows fixing drivers which use the private data in their ->remove()
hook after it's been freed.  It also allows fixing drivers which neglect
to release a reference on the spi_controller in the probe error path.

Long-term, most SPI drivers shall be moved over to the devm functions
introduced herein.  The few that can't shall be changed in a treewide
commit to explicitly release the last reference on the controller.
That commit shall amend spi_unregister_controller() to no longer release
a reference, thereby completing the migration.

As a result, the behaviour will be less surprising and more consistent
with subsystems such as IIO, which also includes the private data in the
allocation of the generic iio_dev struct, but calls device_del() in
iio_device_unregister().

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/272bae2ef08abd21388c98e23729886663d19192.1605121038.git.lukas@wunner.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-11-12 15:05:34 +00:00
Oleksij Rempel
029b42d851
spi: introduce SPI_MODE_X_MASK macro
Provide a macro to filter all SPI_MODE_0,1,2,3 mode in one run.

The latest SPI framework will parse the devicetree in following call
sequence: of_register_spi_device() -> of_spi_parse_dt()
So, driver do not need to pars the devicetree and will get prepared
flags in the probe.

On one hand it is good far most drivers. On other hand some drivers need to
filter flags provide by SPI framework and apply know to work flags. This drivers
may use SPI_MODE_X_MASK to filter MODE flags and set own, known flags:
  spi->flags &= ~SPI_MODE_X_MASK;
  spi->flags |= SPI_MODE_0;

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20201027095724.18654-2-o.rempel@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-11-11 12:39:30 +00:00
Colton Lewis
cfd97f94d0
spi: correct kernel-doc inconsistency
Silence documentation build warnings by correcting kernel-doc comment
for spi_transfer struct.

Signed-off-by: Colton Lewis <colton.w.lewis@protonmail.com>
Link: https://lore.kernel.org/r/20200725050242.279548-1-colton.w.lewis@protonmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-07-27 14:55:22 +01:00