Patchset is named as PCIe Enclosure LED Management because it adds two features: - Native PCIe Enclosure Management (NPEM) - PCIe SSD Status LED Management (DSM) Both are pattern oriented standards, they tell which "indication" should blink. It doesn't control physical LED or pattern visualization. Overall, driver is simple but it was not simple to fit it into interfaces we have in kernel (We considered leds and enclosure interfaces). It reuses leds interface, this approach seems to be the best because: - leds are actively maintained, no new interface added. - leds do not require any extensions, enclosure needs to be adjusted first. There are trade-offs: - "brightness" is the name of sysfs file to control led. It is not natural to use brightness to set patterns, that is why multiple led devices are created (one per indication); - Update of one led may affect other leds, led triggers may not work as expected. Changes from v1: - Renamed "pattern" to indication. - DSM support added. - fixed nits reported by Bjorn. Changes from v2: - Introduce lazy loading to allow DELL _DSM quirks to work, reported by Stuart. - leds class initcall moved up in Makefile, proposed by Dan. - fix other nits reported by Dan and Iipo. Changes from v3: - Remove unnecessary packed attr. - Fix doc issue reported by lkp. - Fix read_poll_timeout() error handling reported by Iipo. - Minor fixes reported by Christoph. Changes from v4: - Use 0 / 1 instead of LED_OFF/LED_ON, suggested by Marek. - Documentation added, suggested by Bjorn. Suggested-by: Lukas Wunner <lukas@xxxxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> Tested-by: Stuart Hayes <stuart.w.hayes@xxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Ilpo Jarvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> Cc: Lukas Wunner <lukas@xxxxxxxxx> Cc: Keith Busch <kbusch@xxxxxxxxxx> Cc: Marek Behun <marek.behun@xxxxxx> Cc: Pavel Machek <pavel@xxxxxx> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Cc: Stuart Hayes <stuart.w.hayes@xxxxxxxxx> Link: https://lore.kernel.org/linux-pci/20240711083009.5580-1-mariusz.tkaczyk@xxxxxxxxxxxxxxx/ Mariusz Tkaczyk (3): leds: Init leds class earlier PCI/NPEM: Add Native PCIe Enclosure Management support PCI/NPEM: Add _DSM PCIe SSD status LED management Documentation/ABI/testing/sysfs-bus-pci | 72 +++ drivers/Makefile | 4 +- drivers/pci/Kconfig | 9 + drivers/pci/Makefile | 1 + drivers/pci/npem.c | 590 ++++++++++++++++++++++++ drivers/pci/pci.h | 8 + drivers/pci/probe.c | 2 + drivers/pci/remove.c | 2 + include/linux/pci.h | 3 + include/uapi/linux/pci_regs.h | 35 ++ 10 files changed, 725 insertions(+), 1 deletion(-) create mode 100644 drivers/pci/npem.c -- 2.35.3
