| Message ID | cover.1623201081.git.vilhelm.gray@gmail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Introduce the Counter character device interface | expand |
On Wed, 9 Jun 2021 10:31:03 +0900 William Breathitt Gray <vilhelm.gray@gmail.com> wrote: > Changes in v11: > - Migrated Intel QEP to new interface > - Context adjustments made for documentation > > I pulled out a lot of bits and pieces to their own patches; hopefully > that makes reviewing this patchset much simpler than before. This > patchset is also available on my personal public git repo for anyone who > wants a quick way to clone: > https://gitlab.com/vilhelmgray/iio/-/tree/counter_chrdev_v11 > > 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. Let us aim to do that in the interests of cutting down on the volume for future versions! However, it is made tricky by the fact patch 22 hasn't made it to me or lore.kernel.org. Could you send that one again. Hopefully the in-reply-to will ensure it's correctly threaded. Jonathan > > 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. > > Something that should still be discussed: should the struct > counter_event "status" member be 8 bits or 32 bits wide? This member > will provide the return status (system error number) of an event > operation. > > William Breathitt Gray (33): > docs: counter: Consolidate Counter sysfs attributes documentation > docs: counter: Fix spelling > counter: 104-quad-8: Remove pointless comment > counter: 104-quad-8: Return error when invalid mode during > ceiling_write > counter: 104-quad-8: Annotate hardware config module parameter > counter: 104-quad-8: Add const qualifiers for > quad8_preset_register_set > counter: 104-quad-8: Add const qualifier for functions_list array > counter: interrupt-cnt: Add const qualifier for functions_list array > counter: microchip-tcb-capture: Add const qualifier for functions_list > array > counter: stm32-lptimer-cnt: Add const qualifier for functions_list > array > counter: stm32-timer-cnt: Add const qualifier for functions_list array > counter: 104-quad-8: Add const qualifier for actions_list array > counter: ftm-quaddec: Add const qualifier for actions_list array > counter: interrupt-cnt: Add const qualifier for actions_list array > counter: microchip-tcb-capture: Add const qualifier for actions_list > array > counter: stm32-lptimer-cnt: Add const qualifier for actions_list array > counter: stm32-timer-cnt: Add const qualifier for actions_list array > 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 | 112 +- > .../ABI/testing/sysfs-bus-counter-104-quad-8 | 61 - > .../ABI/testing/sysfs-bus-counter-ftm-quaddec | 16 - > Documentation/driver-api/generic-counter.rst | 368 +++- > .../userspace-api/ioctl/ioctl-number.rst | 1 + > MAINTAINERS | 7 +- > drivers/counter/104-quad-8.c | 739 ++++---- > drivers/counter/Kconfig | 6 +- > drivers/counter/Makefile | 1 + > drivers/counter/counter-chrdev.c | 486 ++++++ > drivers/counter/counter-chrdev.h | 14 + > drivers/counter/counter-core.c | 192 +++ > drivers/counter/counter-sysfs.c | 953 +++++++++++ > drivers/counter/counter-sysfs.h | 13 + > drivers/counter/counter.c | 1496 ----------------- > drivers/counter/ftm-quaddec.c | 61 +- > drivers/counter/intel-qep.c | 150 +- > drivers/counter/interrupt-cnt.c | 75 +- > drivers/counter/microchip-tcb-capture.c | 105 +- > drivers/counter/stm32-lptimer-cnt.c | 176 +- > drivers/counter/stm32-timer-cnt.c | 149 +- > drivers/counter/ti-eqep.c | 221 +-- > include/linux/counter.h | 716 ++++---- > include/linux/counter_enum.h | 45 - > include/uapi/linux/counter.h | 133 ++ > tools/Makefile | 13 +- > tools/counter/Build | 1 + > tools/counter/Makefile | 53 + > tools/counter/counter_example.c | 95 ++ > 29 files changed, 3586 insertions(+), 2872 deletions(-) > delete mode 100644 Documentation/ABI/testing/sysfs-bus-counter-104-quad-8 > delete mode 100644 Documentation/ABI/testing/sysfs-bus-counter-ftm-quaddec > 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 >
On Wed, Jun 09, 2021 at 02:59:51PM +0100, Jonathan Cameron wrote: > On Wed, 9 Jun 2021 10:31:03 +0900 > William Breathitt Gray <vilhelm.gray@gmail.com> wrote: > > > Changes in v11: > > - Migrated Intel QEP to new interface > > - Context adjustments made for documentation > > > > I pulled out a lot of bits and pieces to their own patches; hopefully > > that makes reviewing this patchset much simpler than before. This > > patchset is also available on my personal public git repo for anyone who > > wants a quick way to clone: > > https://gitlab.com/vilhelmgray/iio/-/tree/counter_chrdev_v11 > > > > 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. > > Let us aim to do that in the interests of cutting down on the volume for future > versions! > > However, it is made tricky by the fact patch 22 hasn't made it to me or > lore.kernel.org. Could you send that one again. Hopefully the in-reply-to > will ensure it's correctly threaded. > > Jonathan I think patch 22 just took a while to be processed by the servers because of its size; I went ahead and submitted a RESEND of it regardless just in case. You should be able to access both on lore.kernel.org: https://lore.kernel.org/lkml/87dec6c889e40068ed27cbb3e66a6376856e2267.1623201082.git.vilhelm.gray@gmail.com/ https://lore.kernel.org/lkml/20210609141145.Ci-kBe7zxq4hPKS98nEi0JK7WOv0DHLOIm8pmrIDvVY@z/ Let me know if you encounter any other problems. William Breathitt Gray
On Wed, 9 Jun 2021 23:11:45 +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. > > Cc: Syed Nayyar Waris <syednwaris@gmail.com> > Cc: Jarkko Nikula <jarkko.nikula@linux.intel.com> > Cc: Patrick Havelange <patrick.havelange@essensium.com> > Cc: Kamel Bouhara <kamel.bouhara@bootlin.com> > Cc: Fabrice Gasnier <fabrice.gasnier@st.com> > Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> > Cc: Alexandre Torgue <alexandre.torgue@st.com> > Cc: Dan Carpenter <dan.carpenter@oracle.com> > Reviewed-by: David Lechner <david@lechnology.com> > Tested-by: David Lechner <david@lechnology.com> > Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> Given you will probably do a v12 anyway, a few comments inline. Jonathan > --- > MAINTAINERS | 1 - > drivers/counter/104-quad-8.c | 449 +++---- > drivers/counter/Makefile | 1 + > drivers/counter/counter-core.c | 155 +++ > drivers/counter/counter-sysfs.c | 846 +++++++++++++ > drivers/counter/counter-sysfs.h | 13 + > drivers/counter/counter.c | 1496 ----------------------- > drivers/counter/ftm-quaddec.c | 56 +- > drivers/counter/intel-qep.c | 144 +-- > drivers/counter/interrupt-cnt.c | 62 +- > drivers/counter/microchip-tcb-capture.c | 93 +- > drivers/counter/stm32-lptimer-cnt.c | 162 ++- > drivers/counter/stm32-timer-cnt.c | 147 +-- > drivers/counter/ti-eqep.c | 180 +-- > include/linux/counter.h | 629 +++++----- > include/linux/counter_enum.h | 45 - > 16 files changed, 1918 insertions(+), 2561 deletions(-) > 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 > ... > diff --git a/drivers/counter/counter-core.c b/drivers/counter/counter-core.c > new file mode 100644 > index 000000000000..e7dd6ea01c8a > --- /dev/null > +++ b/drivers/counter/counter-core.c > @@ -0,0 +1,155 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Generic Counter interface > + * Copyright (C) 2020 William Breathitt Gray > + */ > +#include <linux/counter.h> > +#include <linux/device.h> > +#include <linux/export.h> > +#include <linux/gfp.h> > +#include <linux/idr.h> > +#include <linux/init.h> > +#include <linux/module.h> > + > +#include "counter-sysfs.h" > + > +/* Provides a unique ID for each counter device */ > +static DEFINE_IDA(counter_ida); > + ... > +int counter_register(struct counter_device *const counter) > +{ > + struct device *const dev = &counter->dev; > + int id; > + int err; > + > + /* Acquire unique ID */ > + id = ida_alloc(&counter_ida, GFP_KERNEL); > + if (id < 0) > + return id; > + > + /* Configure device structure for Counter */ > + dev->id = id; > + dev->type = &counter_device_type; > + dev->bus = &counter_bus_type; > + if (counter->parent) { > + dev->parent = counter->parent; > + dev->of_node = counter->parent->of_node; > + } > + device_initialize(dev); > + dev_set_drvdata(dev, counter); > + > + /* Add Counter sysfs attributes */ > + err = counter_sysfs_add(counter); > + if (err < 0) > + goto err_free_id; > + > + /* Add device to system */ > + err = device_add(dev); > + if (err < 0) > + goto err_free_id; > + > + return 0; > + > +err_free_id: > + put_device(dev); > + return err; > +} > +EXPORT_SYMBOL_GPL(counter_register); > + > +/** > + * counter_unregister - unregister Counter from the system > + * @counter: pointer to Counter to unregister > + * > + * The Counter is unregistered from the system; all allocated memory is freed. If we are being fussy. This isn't necessarily true. If the reference goes down to 0 it will be freed, but in theory that could happen later than this call. I'm guessing we will have get_device() calls once the chrdev is in place. > + */ > +void counter_unregister(struct counter_device *const counter) > +{ > + if (!counter) > + return; > + > + device_unregister(&counter->dev); > +} > +EXPORT_SYMBOL_GPL(counter_unregister); > + > +static void devm_counter_release(struct device *dev, void *res) > +{ > + counter_unregister(*(struct counter_device **)res); > +} > + > +/** > + * devm_counter_register - Resource-managed counter_register > + * @dev: device to allocate counter_device for > + * @counter: pointer to Counter to register > + * > + * Managed counter_register. The Counter registered with this function is > + * automatically unregistered on driver detach. This function calls > + * counter_register internally. Refer to that function for more information. > + * > + * RETURNS: > + * 0 on success, negative error number on failure. > + */ > +int devm_counter_register(struct device *dev, > + struct counter_device *const counter) > +{ > + struct counter_device **ptr; > + int err; > + > + ptr = devres_alloc(devm_counter_release, sizeof(*ptr), GFP_KERNEL); > + if (!ptr) > + return -ENOMEM; If you look at how devm_iio_device_register() is now done in the togreg branch of iio.git, you'll see it now just uses devm_add_action_or_reset() internally. I think you could do something similar here and reduce boilerplate a little. > + > + err = counter_register(counter); > + if (err < 0) { > + devres_free(ptr); > + return err; > + } > + > + *ptr = counter; > + devres_add(dev, ptr); > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(devm_counter_register); > + > +static int __init counter_init(void) > +{ > + return bus_register(&counter_bus_type); > +} > + > +static void __exit counter_exit(void) > +{ > + bus_unregister(&counter_bus_type); > +} > + > +subsys_initcall(counter_init); > +module_exit(counter_exit); > + > +MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>"); > +MODULE_DESCRIPTION("Generic Counter interface"); > +MODULE_LICENSE("GPL v2"); > diff --git a/drivers/counter/counter-sysfs.c b/drivers/counter/counter-sysfs.c > new file mode 100644 > index 000000000000..07588130600a > --- /dev/null > +++ b/drivers/counter/counter-sysfs.c > @@ -0,0 +1,846 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Generic Counter sysfs interface > + * Copyright (C) 2020 William Breathitt Gray > + */ > +#include <linux/counter.h> > +#include <linux/device.h> > +#include <linux/err.h> > +#include <linux/gfp.h> > +#include <linux/kernel.h> > +#include <linux/list.h> > +#include <linux/string.h> > +#include <linux/sysfs.h> > +#include <linux/types.h> > + > +#include "counter-sysfs.h" > + ...
Changes in v11: - Migrated Intel QEP to new interface - Context adjustments made for documentation I pulled out a lot of bits and pieces to their own patches; hopefully that makes reviewing this patchset much simpler than before. This patchset is also available on my personal public git repo for anyone who wants a quick way to clone: https://gitlab.com/vilhelmgray/iio/-/tree/counter_chrdev_v11 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. Something that should still be discussed: should the struct counter_event "status" member be 8 bits or 32 bits wide? This member will provide the return status (system error number) of an event operation. William Breathitt Gray (33): docs: counter: Consolidate Counter sysfs attributes documentation docs: counter: Fix spelling counter: 104-quad-8: Remove pointless comment counter: 104-quad-8: Return error when invalid mode during ceiling_write counter: 104-quad-8: Annotate hardware config module parameter counter: 104-quad-8: Add const qualifiers for quad8_preset_register_set counter: 104-quad-8: Add const qualifier for functions_list array counter: interrupt-cnt: Add const qualifier for functions_list array counter: microchip-tcb-capture: Add const qualifier for functions_list array counter: stm32-lptimer-cnt: Add const qualifier for functions_list array counter: stm32-timer-cnt: Add const qualifier for functions_list array counter: 104-quad-8: Add const qualifier for actions_list array counter: ftm-quaddec: Add const qualifier for actions_list array counter: interrupt-cnt: Add const qualifier for actions_list array counter: microchip-tcb-capture: Add const qualifier for actions_list array counter: stm32-lptimer-cnt: Add const qualifier for actions_list array counter: stm32-timer-cnt: Add const qualifier for actions_list array 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 | 112 +- .../ABI/testing/sysfs-bus-counter-104-quad-8 | 61 - .../ABI/testing/sysfs-bus-counter-ftm-quaddec | 16 - Documentation/driver-api/generic-counter.rst | 368 +++- .../userspace-api/ioctl/ioctl-number.rst | 1 + MAINTAINERS | 7 +- drivers/counter/104-quad-8.c | 739 ++++---- drivers/counter/Kconfig | 6 +- drivers/counter/Makefile | 1 + drivers/counter/counter-chrdev.c | 486 ++++++ drivers/counter/counter-chrdev.h | 14 + drivers/counter/counter-core.c | 192 +++ drivers/counter/counter-sysfs.c | 953 +++++++++++ drivers/counter/counter-sysfs.h | 13 + drivers/counter/counter.c | 1496 ----------------- drivers/counter/ftm-quaddec.c | 61 +- drivers/counter/intel-qep.c | 150 +- drivers/counter/interrupt-cnt.c | 75 +- drivers/counter/microchip-tcb-capture.c | 105 +- drivers/counter/stm32-lptimer-cnt.c | 176 +- drivers/counter/stm32-timer-cnt.c | 149 +- drivers/counter/ti-eqep.c | 221 +-- include/linux/counter.h | 716 ++++---- include/linux/counter_enum.h | 45 - include/uapi/linux/counter.h | 133 ++ tools/Makefile | 13 +- tools/counter/Build | 1 + tools/counter/Makefile | 53 + tools/counter/counter_example.c | 95 ++ 29 files changed, 3586 insertions(+), 2872 deletions(-) delete mode 100644 Documentation/ABI/testing/sysfs-bus-counter-104-quad-8 delete mode 100644 Documentation/ABI/testing/sysfs-bus-counter-ftm-quaddec 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