On Sat, Jun 14, 2025 at 10:50:37AM +0800, Binbin Zhou wrote: > Hi Corey: > > On Sat, Jun 14, 2025 at 8:41 AM Corey Minyard <co...@minyard.net> wrote: > > > > On Fri, Jun 13, 2025 at 02:43:38PM +0800, Binbin Zhou wrote: > > > Hi all: > > > > > > This patch set introduces the Loongson-2K BMC. > > > > > > It is a PCIe device present on servers similar to the Loongson-3 CPUs. > > > And it is a multifunctional device (MFD), such as display as a > > > sub-function > > > of it. > > > > I've asked this before, but I haven't gotten a answer, I don't think. > > > > Is this really a multi-function device? Is there (or will there be) > > another driver that uses the MFD code? > > I am very sorry, I may have overlooked your previous question. > > And I also may not have a thorough understanding of multifunction devices. > > The Loongson-2K BMC device provides two functions: display and IPMI. > For display, we pass the simplefb_platform_data parameter and register > the simpledrm device, as shown in patch-1. > > Therefore, I think this should be considered a multifunction device.
Ok, that's clear, thank you. However, that's not really very clear from the patches you have provided. Particularly, the "bmc" in the name from patch 1 makes one think that it's only a bmc. The "bmc" name is also a little confusing; the devices with a "bmc" in the name are all the BMC side, but you are doing a host side device. If you look at most of the other MFDs, they have a "core" section then various other parts that use the core. And possibly parts in other directories for individual functions. I think you need to do the same design. Have a "core" section that both the display and bmc use, then a separate display and bmc driver. That way, you can use the display without the IPMI interface, or the IPMI interface without the display. I would like to see: * A core mfd device named ls2k-core.c that has the core functions. It would have its own config item (MFD_LS2K) that would be selected if either the display or IPMI device is enabled. * A separate display device in its own file with its own config item. This isn't my area, so I'm not sure where this should go. * The IPMI device in the ipmi directory named ipmi_ls2k.c, again with it's own config item (IPMI_LS2K). Does that make sense? I don't want to make things too hard, but that's the way pretty much everything else is done on MFDs. Thanks, -corey > > > > > If nothing else is going to use this, then it's really not a > > multi-function device and all the code can go into the IPMI directory. > > That simplifies maintenance. > > > > If it is a multi-function device, then I want two separate Kconfig > > items, one for the MFD and one for the IPMI portion. That way it's > > ready and you don't have to bother about the IPMI portion when > > adding the other device. > > > > All else looks good, I think. > > > > -corey > > > > > > > > For IPMI, according to the existing design, we use software simulation to > > > implement the KCS interface registers: Stauts/Command/Data_Out/Data_In. > > > > > > Also since both host side and BMC side read and write kcs status, we use > > > fifo pointer to ensure data consistency. > > > > > > For the display, based on simpledrm, the resolution is read from a fixed > > > position in the BMC since the hardware does not support auto-detection > > > of the resolution. Of course, we will try to support multiple > > > resolutions later, through a vbios-like approach. > > > > > > Especially, for the BMC reset function, since the display will be > > > disconnected when BMC reset, we made a special treatment of re-push. > > > > > > Based on this, I will present it in four patches: > > > patch-1: BMC device PCI resource allocation. > > > patch-2: BMC reset function support > > > patch-3: IPMI implementation > > > > > > Thanks. > > > > > > ------- > > > V4: > > > - Add Reviewed-by tag; > > > - Change the order of the patches. > > > Patch (1/3): > > > - Fix build warning by lkp: Kconfig tristate -> bool > > > - https://lore.kernel.org/all/202505312022.qmfmge1f-...@intel.com/ > > > - Update commit message; > > > - Move MFD_LS2K_BMC after MFD_INTEL_M10_BMC_PMCI in Kconfig and > > > Makefile. > > > Patch (2/3): > > > - Remove unnecessary newlines; > > > - Rename ls2k_bmc_check_pcie_connected() to > > > ls2k_bmc_pcie_is_connected(); > > > - Update comment message. > > > Patch (3/3): > > > - Remove unnecessary newlines. > > > > > > Link to V3: > > > https://lore.kernel.org/all/cover.1748505446.git.zhoubin...@loongson.cn/ > > > > > > V3: > > > Patch (1/3): > > > - Drop "MFD" in title and comment; > > > - Fromatting code; > > > - Add clearer comments. > > > Patch (2/3): > > > - Rebase linux-ipmi/next tree; > > > - Use readx()/writex() to read and write IPMI data instead of structure > > > pointer references; > > > - CONFIG_LOONGARCH -> MFD_LS2K_BMC; > > > - Drop unused output. > > > Patch (3/3): > > > - Inline the ls2k_bmc_gpio_reset_handler() function to > > > ls2k_bmc_pdata_initial(); > > > - Add clearer comments. > > > - Use proper multi-line commentary as per the Coding Style documentation; > > > - Define all magic numbers. > > > > > > Link to V2: > > > https://lore.kernel.org/all/cover.1747276047.git.zhoubin...@loongson.cn/ > > > > > > V2: > > > - Drop ls2kdrm, use simpledrm instead. > > > Patch (1/3): > > > - Use DEFINE_RES_MEM_NAMED/MFD_CELL_RES simplified code; > > > - Add resolution fetching due to replacing the original display > > > solution with simpledrm; > > > - Add aperture_remove_conflicting_devices() to avoid efifb > > > conflict with simpledrm. > > > Patch (3/3): > > > - This part of the function, moved from the original ls2kdrm to mfd; > > > - Use set_console to implement the Re-push display function. > > > > > > Link to V1: > > > https://lore.kernel.org/all/cover.1735550269.git.zhoubin...@loongson.cn/ > > > > > > Binbin Zhou (3): > > > mfd: ls2kbmc: Introduce Loongson-2K BMC core driver > > > mfd: ls2kbmc: Add Loongson-2K BMC reset function support > > > ipmi: Add Loongson-2K BMC support > > > > > > drivers/char/ipmi/Makefile | 1 + > > > drivers/char/ipmi/ipmi_si.h | 7 + > > > drivers/char/ipmi/ipmi_si_intf.c | 3 + > > > drivers/char/ipmi/ipmi_si_ls2k.c | 189 ++++++++++++ > > > drivers/mfd/Kconfig | 12 + > > > drivers/mfd/Makefile | 2 + > > > drivers/mfd/ls2kbmc-mfd.c | 485 +++++++++++++++++++++++++++++++ > > > 7 files changed, 699 insertions(+) > > > create mode 100644 drivers/char/ipmi/ipmi_si_ls2k.c > > > create mode 100644 drivers/mfd/ls2kbmc-mfd.c > > > > > > > > > base-commit: cd2e103d57e5615f9bb027d772f93b9efd567224 > > > -- > > > 2.47.1 > > > > > > -- > Thanks. > Binbin _______________________________________________ Openipmi-developer mailing list Openipmi-developer@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openipmi-developer
