| Message ID | cover.1627990337.git.vilhelm.gray@gmail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Introduce the Counter character device interface | expand |
On Sun, Aug 08, 2021 at 06:23:25PM +0100, Jonathan Cameron wrote: > On Tue, 3 Aug 2021 21:06:16 +0900 > William Breathitt Gray <vilhelm.gray@gmail.com> wrote: > > > This is a reimplementation of the Generic Counter driver interface. > > There are no modifications to the Counter subsystem userspace interface, > > so existing userspace applications should continue to run seamlessly. > > > > The purpose of this patch is to internalize the sysfs interface code > > among the various counter drivers into a shared module. Counter drivers > > pass and take data natively (i.e. u8, u64, etc.) and the shared counter > > module handles the translation between the sysfs interface and the > > device drivers. This guarantees a standard userspace interface for all > > counter drivers, and helps generalize the Generic Counter driver ABI in > > order to support the Generic Counter chrdev interface (introduced in a > > subsequent patch) without significant changes to the existing counter > > drivers. > > > > Note, Counter device registration is the same as before: drivers > > populate a struct counter_device with components and callbacks, then > > pass the structure to the devm_counter_register function. However, > > what's different now is how the Counter subsystem code handles this > > registration internally. > > > > Whereas before callbacks would interact directly with sysfs data, this > > interaction is now abstracted and instead callbacks interact with native > > C data types. The counter_comp structure forms the basis for Counter > > extensions. > > > > The counter-sysfs.c file contains the code to parse through the > > counter_device structure and register the requested components and > > extensions. Attributes are created and populated based on type, with > > respective translation functions to handle the mapping between sysfs and > > the counter driver callbacks. > > > > The translation performed for each attribute is straightforward: the > > attribute type and data is parsed from the counter_attribute structure, > > the respective counter driver read/write callback is called, and sysfs > > I/O is handled before or after the driver read/write function is called. > > Hi William, > > There are some issues with this even after I've fixed the merge conflict > because of the earlier change.. > > DESCEND objtool > CALL scripts/atomic/check-atomics.sh > CALL scripts/checksyscalls.sh > CHK include/generated/compile.h > CC [M] drivers/counter/counter-core.o > CC [M] drivers/counter/counter-sysfs.o > CC [M] drivers/counter/104-quad-8.o > CC [M] drivers/counter/interrupt-cnt.o > CC [M] drivers/counter/stm32-timer-cnt.o > CC [M] drivers/counter/stm32-lptimer-cnt.o > drivers/counter/counter-core.c: In function ‘counter_device_release’: > drivers/counter/counter-core.c:23:9: error: implicit declaration of function ‘counter_chrdev_remove’ [-Werror=implicit-function-declaration] > 23 | counter_chrdev_remove(counter); > | ^~~~~~~~~~~~~~~~~~~~~ > cc1: some warnings being treated as errors > make[2]: *** [scripts/Makefile.build:271: drivers/counter/counter-core.o] Error 1 > make[2]: *** Waiting for unfinished jobs.... > CHECK drivers/counter/interrupt-cnt.c > CHECK drivers/counter/104-quad-8.c > CHECK drivers/counter/counter-sysfs.c > drivers/counter/stm32-timer-cnt.c:55:9: warning: implicit conversion from ‘enum stm32_count_function’ to ‘enum counter_function’ [-Wenum-conversion] > 55 | STM32_COUNT_SLAVE_MODE_DISABLED, > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > drivers/counter/stm32-timer-cnt.c:56:9: warning: implicit conversion from ‘enum stm32_count_function’ to ‘enum counter_function’ [-Wenum-conversion] > 56 | STM32_COUNT_ENCODER_MODE_1, > | ^~~~~~~~~~~~~~~~~~~~~~~~~~ > drivers/counter/stm32-timer-cnt.c:57:9: warning: implicit conversion from ‘enum stm32_count_function’ to ‘enum counter_function’ [-Wenum-conversion] > 57 | STM32_COUNT_ENCODER_MODE_2, > | ^~~~~~~~~~~~~~~~~~~~~~~~~~ > drivers/counter/stm32-timer-cnt.c:58:9: warning: implicit conversion from ‘enum stm32_count_function’ to ‘enum counter_function’ [-Wenum-conversion] > 58 | STM32_COUNT_ENCODER_MODE_3, > | ^~~~~~~~~~~~~~~~~~~~~~~~~~ > drivers/counter/stm32-timer-cnt.c: In function ‘stm32_count_function_read’: > drivers/counter/stm32-timer-cnt.c:97:27: warning: implicit conversion from ‘enum stm32_count_function’ to ‘enum counter_function’ [-Wenum-conversion] > 97 | *function = STM32_COUNT_SLAVE_MODE_DISABLED; > | ^ > drivers/counter/stm32-timer-cnt.c:100:27: warning: implicit conversion from ‘enum stm32_count_function’ to ‘enum counter_function’ [-Wenum-conversion] > 100 | *function = STM32_COUNT_ENCODER_MODE_1; > | ^ > drivers/counter/stm32-timer-cnt.c:103:27: warning: implicit conversion from ‘enum stm32_count_function’ to ‘enum counter_function’ [-Wenum-conversion] > 103 | *function = STM32_COUNT_ENCODER_MODE_2; > | ^ > drivers/counter/stm32-timer-cnt.c:106:27: warning: implicit conversion from ‘enum stm32_count_function’ to ‘enum counter_function’ [-Wenum-conversion] > 106 | *function = STM32_COUNT_ENCODER_MODE_3; > | ^ > drivers/counter/stm32-lptimer-cnt.c:139:9: warning: implicit conversion from ‘enum stm32_lptim_cnt_function’ to ‘enum counter_function’ [-Wenum-conversion] > 139 | STM32_LPTIM_COUNTER_INCREASE, > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ > drivers/counter/stm32-lptimer-cnt.c:140:9: warning: implicit conversion from ‘enum stm32_lptim_cnt_function’ to ‘enum counter_function’ [-Wenum-conversion] > 140 | STM32_LPTIM_ENCODER_BOTH_EDGE, > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > drivers/counter/stm32-lptimer-cnt.c: In function ‘stm32_lptim_cnt_function_read’: > drivers/counter/stm32-lptimer-cnt.c:195:27: warning: implicit conversion from ‘enum stm32_lptim_cnt_function’ to ‘enum counter_function’ [-Wenum-conversion] > 195 | *function = STM32_LPTIM_COUNTER_INCREASE; > | ^ > drivers/counter/stm32-lptimer-cnt.c:200:27: warning: implicit conversion from ‘enum stm32_lptim_cnt_function’ to ‘enum counter_function’ [-Wenum-conversion] > 200 | *function = STM32_LPTIM_ENCODER_BOTH_EDGE; > | ^ > drivers/counter/104-quad-8.c:58: warning: Function parameter or member 'lock' not described in 'quad8' > CHECK drivers/counter/stm32-timer-cnt.c > CHECK drivers/counter/stm32-lptimer-cnt.c > make[1]: *** [scripts/Makefile.build:514: drivers/counter] Error 2 > make: *** [Makefile:1841: drivers] Error 2 > > I could wait through these but it feels a little to likely I'll mess something up fixing things > so please fix the errors and warnings this patch introduces > with a W=1 C=1 build. > > Also, do a patch by patch build of the rest of the set in case there are any other cases > like this hiding. It's very easy for these to build up when you have a lot of > versions of a patch series. I've been caught out a few times myself! > > In the meantime, I'll keep the first 5 patches on my tree unless you shout otherwise. > > Thanks, > > Jonathan Thanks, I'll fix this up and submit a v15 to make sure these patches merge in smoothly. William Breathitt Gray
Changes in v14: - Initialize counter_fops owner to THIS_MODULE - Implement ops_exist_lock to prevent counter->ops use during removal - Set counter->ops to NULL on counter_unregister to indicate removal; chrdev callbacks return -ENODEV if driver is removed - Refactor counter_fops read, poll, ioctl, and release callbacks to utilize ops_exist_lock where needed and to check counter->ops - Wake up sleeping chrdev read() on counter_unregister - Move chrdev_lock introduce to the "counter: Add character device interface" patch; this is a more appropriate place to introduce this lock because the chrdev code is intended from the get-go to only allow for a single open() at a time For convenience, this patchset is also available on my personal git repo: https://gitlab.com/vilhelmgray/iio/-/tree/counter_chrdev_v14 The patches preceding "counter: Internalize sysfs interface code" are primarily cleanup and fixes that can be picked up and applied now to the IIO tree if so desired. The "counter: Internalize sysfs interface code" patch as well may be considered for pickup because it is relatively safe and makes no changes to the userspace interface. To summarize the main points of this patchset: there are no changes to the existing Counter sysfs userspace interface; a Counter character device interface is introduced that allows Counter events and associated data to be read() by userspace; the events_configure() and watch_validate() driver callbacks are introduced to support Counter events; and IRQ support is added to the 104-QUAD-8 driver, serving as an example of how to support the new Counter events functionality. William Breathitt Gray (17): counter: 104-quad-8: Return error when invalid mode during ceiling_write counter: Return error code on invalid modes counter: Standardize to ERANGE for limit exceeded errors counter: Rename counter_signal_value to counter_signal_level counter: Rename counter_count_function to counter_function counter: Internalize sysfs interface code counter: Update counter.h comments to reflect sysfs internalization docs: counter: Update to reflect sysfs internalization counter: Move counter enums to uapi header counter: Add character device interface docs: counter: Document character device interface tools/counter: Create Counter tools counter: Implement signalZ_action_component_id sysfs attribute counter: Implement *_component_id sysfs attributes counter: Implement events_queue_size sysfs attribute counter: 104-quad-8: Replace mutex with spinlock counter: 104-quad-8: Add IRQ support for the ACCES 104-QUAD-8 Documentation/ABI/testing/sysfs-bus-counter | 38 +- Documentation/driver-api/generic-counter.rst | 358 +++- .../userspace-api/ioctl/ioctl-number.rst | 1 + MAINTAINERS | 3 +- drivers/counter/104-quad-8.c | 728 ++++---- drivers/counter/Kconfig | 6 +- drivers/counter/Makefile | 1 + drivers/counter/counter-chrdev.c | 553 ++++++ drivers/counter/counter-chrdev.h | 14 + drivers/counter/counter-core.c | 192 +++ drivers/counter/counter-sysfs.c | 962 +++++++++++ drivers/counter/counter-sysfs.h | 13 + drivers/counter/counter.c | 1496 ----------------- drivers/counter/ftm-quaddec.c | 59 +- drivers/counter/intel-qep.c | 150 +- drivers/counter/interrupt-cnt.c | 73 +- drivers/counter/microchip-tcb-capture.c | 103 +- drivers/counter/stm32-lptimer-cnt.c | 211 ++- drivers/counter/stm32-timer-cnt.c | 147 +- drivers/counter/ti-eqep.c | 205 ++- include/linux/counter.h | 719 ++++---- include/linux/counter_enum.h | 45 - include/uapi/linux/counter.h | 154 ++ tools/Makefile | 13 +- tools/counter/Build | 1 + tools/counter/Makefile | 53 + tools/counter/counter_example.c | 93 + 27 files changed, 3623 insertions(+), 2768 deletions(-) create mode 100644 drivers/counter/counter-chrdev.c create mode 100644 drivers/counter/counter-chrdev.h create mode 100644 drivers/counter/counter-core.c create mode 100644 drivers/counter/counter-sysfs.c create mode 100644 drivers/counter/counter-sysfs.h delete mode 100644 drivers/counter/counter.c delete mode 100644 include/linux/counter_enum.h create mode 100644 include/uapi/linux/counter.h create mode 100644 tools/counter/Build create mode 100644 tools/counter/Makefile create mode 100644 tools/counter/counter_example.c