driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks - driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hello all, I have an Arria 10 SoC device on our custom board. The board boots from an SD Card, loading u-boot and than a Linux kernel. Until now, I used an old u-boot build flow utilized Quartus and the bsp-editor. With a small adaption, u-boot (2014.10) is able to read a MAC address from an external EEPROM connected through an I2C interface. Now I have to switch to a the new u-boot build flow created on the sources: https://github.com/altera-opensource/u-boot-socfpga (2020.04) as described on: https://rocketboards.org/foswiki/Documentation/BuildingBootloader?erpm_id=6579622_ts1606222496230 For our custom board, I adapted the u-boot configuration and device tree blob of the Arria 10 SoC DevKit included in the sources. When configuring the basic Hardware (SD Card, UART, Ethernet, ...) our board is able to boot the Liunx kernel. As soon as, I try to enable and use the I2C interface in u-boot, the kernel isn't able to boot anymore. In configuration I added and activated the following configs: CONFIG_MISC=y CONFIG_I2C_EEPROM=y CONFIG_SYS_I2C_EEPROM_BUS=0 CONFIG_SYS_I2C_EEPROM_ADDR=0x50 CONFIG_SYS_I2C_EEPROM_ADDR_LEN=2 CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW=0 CONFIG_SYS_EEPROM_SIZE=512 CONFIG_SYS_EEPROM_PAGE_WRITE_BITS=0 CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS=0 CONFIG_CMD_EEPROM=y CONFIG_CMD_I2C=y CONFIG_SYS_I2C_DW=y And in the device tree blob I have the I2C hardware: &i2c1 { status = "okay"; clock-frequency = <100000>; eeprom@50 { compatible = "atmel,24c512"; reg = <0x50>; pagesize = <32>; }; }; With this adaption I could enable the I2C hardware in the u-boot console. When I try to boot the Linux kernel afterwards, the HPS gets stuck. I could enclose the issue to the u-boot function dm_remove_devices_flags(DM_REMOVE_ACTIVE_ALL); which is called before the kernel starts. The function loops over the device tree blob and disable all active hardware. This is also done for the I2C driver and its clocks. So the designware_i2c_remove function disables the clock and after disabling the l4_sp_clk the device hangs. Does anyone know, how to prevent the deactivation of the clocks? Does anyone has experience with the use of I2C in u-boot 2020.04? Cheers Silvan Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi, The patch is available in below commits: https://github.com/altera-opensource/u-boot-socfpga/commits/socfpga_v2021.07 5dabf9b144aacdf05baead80e1eb073891a2b510 70fc399466b2bd9eb32f00c33ab918272459ea9f 0bb5d2d0ccec60f8f0136b26525904565fe70538 Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi Mike, Thanks for that nice patch. The system works with it. Also, many thanks for the hint to the u-boot variable socfpga_legacy_reset_compat Silvan Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hello, We had a similar problem trying to migrate to the socfpga_v2021.04 branch of uBoot. We have an on-board EEPROM (I2C) that contains factory configuration data that is needed during the uBoot TPL phase. We are seeing that the designware_i2c I2C controller is resetting the l4_sp_clk when it is removed prior to starting the linux kernel. The result is that there is a bus hang when the kernel tries to access the UART peripheral (which needs that clock). The kernel we are trying to use is from 4.9.78-ltsi. It's possible that later versions of the kernel properly re-enable the l4_sp_clk, but this doesn't seem to be the case for our particular configuration (which works fine with uboot 2014.10). We also had to set the socfpga_legacy_reset_compat=1 uBoot environment variable as well, as without it this version of uBoot will reset all the peripherals as it switches to linux, resulting in a similar hang. Our work-around can be found in this patch here: Critical Link LLC git repositories. - u-boot-socfpga.git/blobdiff - drivers/i2c/designware_i2c.c -Mike Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi all, I am facing a similar issue with USB boot. When i try to boot from USB from u-boot, its hanging at starting kernel. In function "dwc2_usb_remove" of drivers/usb/host/dwc2.c, I tried commenting out two functions, //clk_disable_bulk(&priv->clks); //clk_release_bulk(&priv->clks); Now I am able to see the print " Deasserting all peripheral resets ", but still it's not booting. I also tried not to call "dwc2_usb_remove" function but observed the same. Any idea on this issue? Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi Silvan, We found the root cause of the issue, it seems to be an issue when disabling the l4_sp_clk when Starting the Kernel. So, when I2C is removed before Kernel, it removes the l4_sp_clk, then this would impact other peripherals running, triggering the hang in Uboot when dessaserting the peripherals. To fix the issue, together with enabling the I2C in U-boot, please use the patch (attached) following the steps from: https://rocketboards.org/foswiki/Documentation/BuildingBootloader#Arria_10_SoC_45_Boot_from_SD_Card How to apply the patch, after following "Build U-boot” steps after: git checkout -b test-bootloader -t origin/socfpga_v2021.04 Copy the patch file in the “software/bootloader” folder, and run: patch -p1 < ../enable_i2c_uboot_kernel_fix.patch Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks In the function designware_i2c_remove, comment the following lines. int designware_i2c_remove(struct udevice *dev) { struct dw_i2c *priv = dev_get_priv(dev); #if CONFIG_IS_ENABLED(CLK) //clk_disable(&priv->clk); clk_free(&priv->clk); #endif //return reset_release_bulk(&priv->resets); return 0; } This will fix the booting issue. Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi Eberlazare Please have a look to the file attached in the previous answer!!!!!!!!! I added clocks = <&clk_virt_l4_sp>; to the i2c1 device because the EEPROM which i would use on the DevKit is connected on i2c1 and not i2c0. Do you still think i2c0 is the right place for clocks = <&clk_virt_l4_sp>; ? And what do you think is the reason for that? Please could you put me in touch with an expert from intelFPGA to assist me for solving that issue? Otherwise it seems that we will not be successful! Thanks Silvan Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi, Have you reassigned in the device tree (included where memory is define), that your i2c is using: &i2c0 { clocks = <&clk_virt_l4_sp>; } Instead of for example GHRD's : &i2c0 { clocks = <1000000>; } Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi, U-boot used was 2020.04, I added the below in the configs "u-boot-socfpga/configs/socfpga_arria10_defconfig": CONFIG_CMD_I2C=y CONFIG_DM_I2C=y CONFIG_SYS_I2C_DW=y I see that your configs did not have the middle line " CONFIG_DM_I2C=y ", can you double check? Since the kernel could not be loaded after the i2c callouts, which kernels version have you tested? Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi Hussein, Many thanks for your answer. For me it make sens, that a "fixed-clock" is a workaround to solve this issue. In a first step, I try to implement this on in the device tree for the development board (right now in u-boot 2020.10). I added the clk_virt_l4_sp node in the clock section of the device tree where also the other fixed clocks (osc1, f2s_free_clk, ...) are. For your interest I put the updated socfpga_arria10.dtsi (renamed to *.txt) file in the attach. Now I see an issue when loading the i2c driver. It seams, that no clock frequency is given by the instantiated clock node. One debug output from the driver is: dw_i2c: mode 0, ic_clk 0, speed 100000, period 0 rise 0 fall 0 tlow 0 thigh 0 spk 0 which shows, that the clock frequency is 0. I think, maybe I put the clk_virt_l4_sp definition in the wrong location in the device tree? Do you know the correct location of it? Thanks and best regards, Silvan Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks We have experienced this as well. You have tracked the problem down correctly to DM_REMOVE_ACTIVE_ALL. The problem is that uboot Device Model will try to deactivate the i2c device node, taking down the associated l4_sp_clk with it. There is probably a proper fix for this problem, however doing the following is a workaround: 1. Create a virtual fixed-clock in your uboot dts file. Something like this: clk_virt_l4_sp: clk_virt_l4_sp { #clock-cells = <0>; compatible = "fixed-clock"; clock-frequency = <100000000>; }; The frequency (100MHz here) has to match your FPGA design (check your HPS clock configuration in qsys..). 2. Re-assign the clock of the i2c node you are using to the new virtual fixed clock. Something like this, when done in a dts or dtsi file which includes the main dtsi file (where i2c0 is defined): &i2c0 { clocks = <&clk_virt_l4_sp>; } With this workaround, uboot will not try to deactivate l4_sp_clk before starting the linux kernel and it should boot fine. Hope it helps. Hussein Alasadi ARECS GmbH Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Thanks for your replay. So was you able to reproduce the issue on your side? Maybe you could also share the u-boot binary with me. When you contact your team, please ask also for the documentation of reading the Ethernet MAC address from the EEPROM in u-boot 2020.04 or 2020.10 (same as here for the old version: https://rocketboards.org/foswiki/Documentation/UBootA10HPSEMACAddressEEPROMSupport?elq_cid=4021871_ts1622787621826&erpm_id=6579622_ts1622787621826 ) Or better, please forward them my issue which I observe. Thanks, Silvan Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi Silvan, My apologies for the late respond. For the 2020.04, U-boot, I checked, for the i2c tools. The following configs must be modified and included or my “make menuconfig”. CONFIG_CMD_I2C=y CONFIG_DM_I2C=y CONFIG_SYS_I2C_DW=y The file is in directory of U-boot "configs/socfpga_arria10_defconfig", I am unsure why the above is not set by default, as they are avaialbe in our other devices. I am checking with our internal team on the clarification, and will let you know once I have the reply. Also, from my side I am trying the above on our dev kit as well, for U-boot version 2020.04 with the above config turned on. The default without the above config, the I2C tools does not work. Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi Eberlazare, Any news from your side? Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Thanks for re-try. And please try also to exchange data between u-boot and EEPROM. Only the declaration in the device tree doesn't result in the issue. Using the EEPROM (read or write) from u-boot triggers the issue and let the system crash in the following boot process. Let me know when you have any news. Thanks and best regards, Silvan Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi Silvan, I git from https://github.com/altera-opensource/u-boot-socfpga/tree/socfpga_v2020.10 I shall re-try again using dev kit today, and configure and enable the I2C and EEPROM drivers in Uboot. Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks And on question more: What can we do, to solve the issue faster. Right now, we are discussion since more than 5 month without any change or output. In the meantime it becomes important to solve this issue. Thanks, Silvan Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi Eberlazare, On my side there is still an issue. Which u-boot version (commit ID) do you used? And what was the u-boot configuration applied for the i2c access test? Maybe you could share your binaries with me? Attached you find my version of u-boot 2020.10: https://github.com/altera-opensource/u-boot-socfpga.git branch: socfpga_v2020.10 commit: c79c23c6201819ca32b6739eff2e2b25e19f6624 I enabled the I2C drivers and EEPROM drivers in the configuration. The resulting socfpga_arria10_defconfig is also in the attachment. In u-boot I tried to enable and use the devices with the u-boot command 'i2c' and 'eeprom'. In both cases, the system hangs afterwards. Do you see any different between your tests and my one? Thanks for your support, Silvan Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi, I am not seeing the issue with 2020.10 Uboot with the default GHRDs, I am trying different type of UBoot and checking the device tree of I2c individually . Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Thanks for the information. Are you already able to reproduce the issue on your side? And now you are looking for fixes? Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi, Just an update, I am still working on this issue. Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks hi Silvan, Thanks for this followup, I think we can check with the changes made from 2014.10 to 2020.04, since you mentioned it worked on 2014. For 2020.11 uboot GHRD: https://releases.rocketboards.org/release/2020.11/gsrd/a10_gsrd/ I can re-try using on Dev Kit and test from my side, it may take a few days. Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hello Eberlazare, Thanks for the link. The GSRD used in the movie is version 17.0 which use u-boot 2014.10. With this version I'm able to get access to the EEPROM connected on the I2C bus. What I'm looking for, is exact the same procedure for the actual version of the GSRD (2020.11). This version use u-boot 2020.04 in which I'm not able to get the I2C access running as described in my first request. Do you have such example using GSRD 2020.11 including u-boot 2020.11? Or please, could you reproduce the issue on your side for this version? Do you need additional information for that? Thanks, Silvan Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi, Ww have a video on the demo to do this via Uboot: https://www.youtube.com/watch?v=2uC2r8YMUOA&ab_channel=IntelFPGA Let me know if you're having trouble on the steps from the video. Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi Eberlazare, In the meantime I've got the current version of intels arria10 development board (Rev. C). I started with the current version of the GSRD v20.1 from https://rocketboards.org/foswiki/Documentation/Arria10SoCGSRD I still run into troubles by using the i2c device from u-boot. Do you have any examples or documentation how to get access to the EEPROM on the development board from u-boot? I'm looking for the current version of the following description: https://rocketboards.org/foswiki/Documentation/UBootA10HPSEMACAddressEEPROMSupport This is exactly what I try to do. Read the Ethernet MAC address from the external EEPROM. Thanks also for the documentation to the ARM DS debugging instructions. I'm not sure if it is exactly what we want. Because the documentation describes how to debug u-boot SPL. In our case, the u-boot SPL works fine and loads the full version of u-boot into the external RAM. The I2C issues are in the full u-boot image... Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi, The only thing I could think of is to try to debug using ARM DS and see where the steps stops. https://rocketboards.org/foswiki/Documentation/SoCEDS#Run_U_45Boot_SPL_from_Debugger Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks The issue is still there. It is independent on the EEPROM type because the initialization of the I2C Hardware results into the issue. (On the u-boot console I could setup the I2C hardware without the initialization of external I2C device like the EEPROM) Do you have additional information or are you able to reproduce the issue on your side? Thanks, Silvan Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi, Any follow-up from your side? Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi, My recommendation is to check with default settings of GHRD and UBoot. According to 2020.04 the device tree settings are set as per below: &i2c1 { status = "okay"; /* * adjust the falling times to decrease the i2c frequency to 50Khz * because the LCD module does not work at the standard 100Khz */ clock-frequency = <100000>; i2c-sda-falling-time-ns = <6000>; i2c-scl-falling-time-ns = <6000>; adc@14 { compatible = "lltc,ltc2497"; reg = <0x14>; vref-supply = <&ref_033v>; }; adc@16 { compatible = "lltc,ltc2497"; reg = <0x16>; vref-supply = <&ref_033v>; }; eeprom@51 { compatible = "atmel,24c32"; reg = <0x51>; pagesize = <32>; }; rtc@68 { compatible = "dallas,ds1339"; reg = <0x68>; }; ltc@5c { compatible = "ltc2977"; reg = <0x5c>; }; }; The difference is the EEPROM part and also you did not specify the SDA and SCL falling time. I am unsure if adding the falling time would prevent the clock to be deactivated but it is worth a try. Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi Eberlazare, No your assumption is wrong. I see such issue in Uboot! So I changed the Uboot device tree and using the I2C hardware in Uboot. After that, I'm not able to boot an Linux because Uboot never try to load and start the Linux as described in my previous post. Did you has any idea for that issue? And what is the recommendation from intel to using the I2C hardware in Uboot? Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi, Yes as per my experience, it is required as you are running in Linux. Correct me if I am wrong, you did change in the Uboot device tree, and in Uboot you are not seeing such issue, but only in Linux am I correct? Have you tried changing the Linux device tree as well? Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi Eberlazare, Thanks for your feedback. I didn’t changed the Linux device tree during the u-boot migration from 2014.10 to 2020.04 . Is it required? I think the issue which I observe in u-boot 2020.04 is shortly before the Linux kernel starts. Our u-boot device tree is based on \arch\arm\dts\socfpga_arria10.dtsi which includes the I2C1 device information (compatible, clock, ...). I think, its configuration is correct because I’m able to communicate with our EEPROM from u-boot. The issue which I’m observe is when u-boot switch to the Linux kernel. Before loading the kernel, u-boot has a clean-up routine to release allocated hardware resources. And at the point when the enabled I2C hardware is released, the system stops to work. I added additional debug/print-outputs in the u-boot sources to isolate the issue. I attached the log on this reply and a description follows bellow. Yes, the old u-boot version 2014.10 used also I2C1 to read the MAC address from an external EEPROM. As far as I understand, the Hardware and FPGA firmware work correctly. So what is the recommendation to enable and use the I2C hardware in u-boot 2020.04 ? Is it wrong to just enable the i2c hardware based on \arch\arm\dts\socfpga_arria10.dtsi ? Short log description: Enabling the I2C device with ‘i2c dev 0’ (Line 44) and list available devices with ‘i2c prob’ (Line 52). Boot Linux kernel with ‘run bootcmd’ (Line 54) Starting log in file: \arch\arm\lib\bootm.c In function ‘announce_and_cleanup(int fake)’ dm_remove_devices_flags(DM_REMOVE_ACTIVE_ALL); is called. (Line 87) The function is implemented in \drivers\core\root.c and calls ‘device_remove’ from \drivers\core\device-remove.c which loops over all active devices and disable it and there child. (Line 88) If I2C active (which is true after calling ‘i2c prob’) (Line 305) the remove function ‘designware_i2c_remove(struct udevice *dev)’ in /drivers/ i2c/designware_i2c.c is called (Line 337) . This function stops the l4_sp_clkclk_disable clock which results in a non working system and after a while the watchdog reboot the device… (Line 339) Replies: Re: driver for HPS I2C Hardware in u-boot 04.2020 deactivates clocks Hi Silvan, I noticed that you changed from the default configuration, thus you may need to change the Linux's device tree as well, you may find in similar directory: \linux-socfpga-socfpga-5.4.54-lts\arch\arm\boot\dts The file is called "socfpga_arria10_socdk". From my experience of changing Uboot settings for a custom board, if you opt to use the Linux, you need to check the Linux's device tree as well. In addition, before changing the device tree, you need to check if the other config of the I2C is reliable to what you looking for, the frequency, compatible, etc.. Also, are you using "I2C1" in the old Uboot that worked? - 2020-11-24