Q&A Contribute to torvalds/linux development by creating an account on GitHub. And I could not find the board.c file for the i.mx6 solo in kernel/.../mach-imx. Add information about your I2C device into the appropriate i2c node reference in the rootfs.dts.STM32F7 file. The nodes for an i2c bus multiplexer/switch will have one child node for each child bus. The device tree is a description of the hardware that is used by the kernel to know which devices are connected. An i2c bus multiplexer/switch will have several child busses that are numbered uniquely in a device dependent manner. In generalone can add additional dts parameter using of_property_read_u32(), use as example "phy-reset-gpios" or write own driver as it is done inhttps://community.nxp.com/thread/384421, Best regardsigor-----------------------------------------------------------------------------------------------------------------------Note: If this post answers your question, please click the Correct Answer button. Optional properties: - #address-cells = <1>; This property is required if the i2c-mux child node does not exist. The kernel then unflattens and parses the device tree. Elixir Cross Referencer - Explore source code in your browser - Particularly useful for the Linux kernel and other low-level projects in C/C++ (bootloaders, C libraries...) Latest Bootlin talks. > >> and implement >> it for the at24 driver. Each I²C device is represented by a sub-node. The device tree is a structure describing the underlying hardware on your platform. It is possible to use the Yocto project to build the device tree as well. However, it will access serial EEPROMs on any I2C adapter. Adding The EEPROM To The Device Tree In order for the Linux kernel to find the driver for the I2C EEPROM on the board the device tree needs to reflect the additional EEPROM on the I2C bus. Linux simply enumerates all I2C buses and gives them a number, but the device tree specifies them by address. I wrote an I2c driver for my custom I2C Master Hardware. machine type is now defined in the device tree itself. The above example registers an EEPROM emulator on STM32 side at slave address 0x64. About Kernel Documentation Linux Kernel Contact Linux Resources Linux Blog. Read more about addresses below. for example of below device tree, the i2c cadence driver will be probe and then the eeprom at24.c driver will also be probe. These are called adaptors, and are assigned dynamically as described in the kernel Documentation file i2c/dev-interface: You should inspect /sys/class/i2c-dev/ or run "i2cdetect -l" to decide this. My Linux is Ubuntu 14.04, kernel 3.13. Its memory contents can be accessed from userspace via this file located in sysfs: Hi, everyone: I am not good at english, but I will try my best to tell my problem, thanks for every's help. They have to be defined statically and are attached to a "platform bus" to give a handle to the device drivers shipped with the kernel. Elixir Cross Referencer. Optional properties: - #address-cells = <1>; This property is required if the i2c … But I have question about the Device tree (dtsi) how to binding the i2c platform data. Do not fall into the temptation of writing the device tree to reflect the current implementation of the operating system. Refer to How to configure the DT using STM32CubeMX for more details. Now, this snippet should be placed under the I2C bus it belongs to. I have a X86 CPU with custom I2C Master Harware. Linux kernel source tree. by Wolfram Sang in 2014-20. (The hardware configuration file is working only with the default bsp file provided by the zedboard site. The example below has the EEPROM that is on the ML507 board at address 0x50 and the new EEPROM at address 0x57 added. In order to add a slave device on an I2C bus, complete the device tree with the information related to the new device. It is used by the STM32 I2C Linux® driver that registers relevant information in the I2C framework. There's no other I2C memory read interface for kernel clients. Contribute to torvalds/linux development by creating an account on GitHub. I need to be able to read the eeprom file of the SFP i2c device. See the Device tree for an explanation of the device tree file split. I was in vacation as Dan mentioned before. It's heavily used in embedded devices since SOCs and stuff don't have buses like PCI where devices can be discovered. mem_acc->read(mem_acc, gmac_addr, offset, ETH_ALEN); for (i = 0; i < 6; i++) { printk("mac_addr[%d]=0x%x\n",i,gmac_addr[i]); }}EXPORT_SYMBOL(get_mac_addr); static void __inline__ fec_get_mac(struct net_device *ndev){ struct fec_enet_private *fep = netdev_priv(ndev); struct fec_platform_data *pdata = fep->pdev->dev.platform_data; unsigned char *iap, tmpaddr[ETH_ALEN]; /* * try to get mac address in following order: * * 1) module parameter via kernel command line in form * fec.macaddr=0x00,0x04,0x9f,0x01,0x30,0xe0 */ iap = macaddr;printk(KERN_INFO "1 ========fec_get_mac==0x%x\n",*iap); /* * 2) from flash or fuse (via platform data) */ if (!is_valid_ether_addr(iap)) {#ifdef CONFIG_M5272 if (FEC_FLASHMAC) iap = (unsigned char *)FEC_FLASHMAC;#else //if (pdata) if((gmac_addr[0]==0xff && gmac_addr[1]==0xff )){ memcpy(iap, pdata->mac, ETH_ALEN); }else{ memcpy(iap, gmac_addr, ETH_ALEN); }#endif, one can check available options in /Documentation/devicetree/bindings/netbut seems there is no way for that. Now I could write and dump the eeprom data from console with command to see the MAC address what I write into. Hello all, I have an Arria 10 SoC device on our custom board. I ran into one too many board with an I2C EEPROM that Linux handled poorly, and got a hack attack. The clock frequency for the I2C bus is configured in this .dtb file, and the default is 100kHz. #lfelc What is I2C? Page generated on 2018-04-09 11:52 EST. Based on kernel version 4.16.1. This backend simulates an EEPROM on the connected I2C bus. at Live Embedded Event. Hmm, and it appears most other I2C EEPROMs too; I happened across a chart with about eight vendors showing part number equivalence. To match these, remember which bus you had to use in your i2cdetect command. The file is in use without any modification.) I am eluded by how exactly to configure the device tree for my external I2C eeprom AND once that happens, how do I use the eeprom driver for linux to read/write the device. Describing non-detectable devices Description through a Device Tree (on ARM, PowerPC, ARC…) In arch/arm/boot/dts/ on ARM Two parts: – Device Tree Source (.dts) One per board to support in the Linux kernel Advantage: no need to write kernel code to support a new board (if all devices are supported). Linux I2C Driver Master, Slave & User space Drivers ... Device Example: RTC, EEPROM & Accelerometer Prerequisites: ... - Add I2C Master/Slave driver platform data in to Device tree source code - Integrating platform (I2C Master) driver and slave driver with framework. Required properties (per bus) ----- - #address-cells - should be <1>. AT24 EEPROM block device Linux driver. 4.4.1 Device tree . //zynq-7000.dtsi. It only takes a minute to sign up. The I2C is represented by: The Generic device tree bindings for I2C busses; The STM32 I2C controller device tree bindings; 3 DT configuration The device driver can be enabled in the kernel: This can be done manually in your kernel: Since the SMBus Alert is relying on a dedicated pin to work, the pinctrl of the I2C controller (here i2c2) must be updated to add the corresponding SMBA pin. This article explains how to configure the I2C internal peripheral[1] when the peripheral is assigned to Linux® OS, and in particular: The configuration is performed using the device tree mechanism[2]. I'm building and testing an application on linux, but I2C will not work. IIC-Bus: i2c@81600000 { compatible = "xlnx,xps-iic-2.00.a"; interrupt-parent = … By listing I2C device in device tree, the LX OS is instructed to load on top of I2C bus device driver (also entry in device tree), an additional specialized (dedicated) driver that knows how to communicate with I2C 24x512 EEPROM registers via I2C bus driver (assuming that specified eeprom driver probe-ing will detect/support 24x512 chip). We assume that attendees are fully fluent in C, data structures and that the Linux/Unix command line is a familiar environment. There are two levels of device tree configuration: The device tree properties related to the I²C internal peripheral and to the I²C bus which belong to i2cx node. STM32CubeMX can be used to generate the board device tree. We have a i.mx6 solo boar with yocto linux 4.1.15 and need porting the i2c eeprom as the MAC address. Please note that the driver is going to use MDMA for data transfer and that SCL rising/falling times have been provided as inputs. /* CAT24C256 EEPROM */ eeprom@50 { compatible = "at,24c256"; reg = <0x50>; page_size = <64>; byte_len = <32768>; flags = <16>; context = <0x0000>; }; 2. mach-mx6/board-mx6q_sabresd.c static struct at24_platform_data eeprom_info = { .byte_len = (256*1024) / 8, .page_size = 64, .flags = AT24_FLAG_ADDR16, .setup = get_mac_addr, .context = (void *)0x0000, }; 3.static struct i2c_board_info mxc_i2c2_board_info[] __initdata = { { I2C_BOARD_INFO("24c256", 0x50), .platform_data = &eeprom_info, }, }; #include #include char gmac_addr[6];void get_mac_addr(struct memory_accessor *mem_acc, void *context){. I am eluded by how exactly to configure the device tree for my external I2C eeprom AND once that happens, how do I use the eeprom driver for linux to read/write the device. #lfelc Linux I2C Drivers • Define and allocate a private data struct (contains struct i2c_adapter) • Fill algorithm struct –.master_xfer() –function to perform transfer –.functionality() –function to retrieve bus functionality. Documentation / devicetree / bindings / i2c / i2c-gpio.txt. But in yocto linux 4.1.15, how to binding the i2c platform data in the device tree dtsi configuration? EEPROMs (I2C) Required properties: - compatible : should be "," If there is no specific driver for , a generic driver based on is selected. Background. Live Embedded Event. Hello all, I have an Arria 10 SoC device on our custom board. My design is based on the canyonlands PPC460EX board. Now I could write and dump the eeprom data from console with command to see the MAC address what I write into. On my system the i2c busses are devices /dev/i2c-0 and so on. 4 5 If a device needs more specific bindings, such as properties to 6 describe some aspect of it, there needs to be a specific binding 7 document for it just like any other devices. Hi Cory, First I would like to apologize for my very late response. */ page_size = 1; This format is a textual representation of a device tree in a form that can be processed by DTC (Device Tree Compiler) into a binary device tree in the form expected by software components: Linux ® Kernel, U-Boot and TF-A. I am using the newest kernel 2.6.27-rc6 since it has apparently the best support for the 28C128 EEPROM devices. Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type. This hardware description is a combination of the STM32 microprocessor device tree files (.dtsi extension) and board device tree files (.dts extension). 2 DT bindings documentation . I am using a buildroot linux kernel for an embedded board. It must be kept as is, without being modified by the end-user. Linux kernel source tree. DDR4 memory information in Linux. However, it will access serial EEPROMs on any I2C adapter. 1 This is a list of trivial i2c devices that have simple device tree 2 bindings, consisting only of a compatible field, an address and 3 possibly an interrupt line. 1.1 Source files .dts: The device tree source (DTS). This format is a textual representation of a device tree in a form that can be processed by DTC (Device Tree Compiler) into a binary device tree in the form expected by software components: Linux ® Kernel, U-Boot and TF-A. I have some linux kernel & SFP/I2C driver issue. The STM32CubeMX may not support all the properties described in the above DT bindings documentation paragraph. [ 2.036834] at24 2-0050: 4096 byte 24c32 EEPROM, writable, 1 bytes/write However, I don’t see EEPROM device is listed under /dev OR /sys/class, but I can see eeprom listed under sys/bus/i2c/devices/2-0050/eeprom Linux kernel source tree. Linux Kernel Documentation. Embedded Linux Porting knowledge. Example : with an EEPROM ), Device Tree Source (in software context) or Digital Temperature Sensor (in peripheral context), Electrically-erasable programmable read-only memory. The EEPROM is accessed over the serial I2C bus using the SLAVE_ADDRESS value of 0x50, where the top 4 serial bits represent a read/write command to the EEPROM, followed by the 4-bit I2C device address of 0. An i2c bus multiplexer/switch will have several child busses that are numbered uniquely in a device dependent manner. The supported devices are generically called 24Cxx, and are listed above; however the numbering for these industry-standard devices may vary by manufacturer. If the peripheral is assigned to another execution context, refer to How to assign an internal peripheral to a runtime context article for guidelines on peripheral assignment and configuration. Approved on: 12:26, 11 June 2020, I²C internal peripheral related properties, Example of an external EEPROM slave device, Example of an EEPROM slave device emulator registering on STM32 side, Example of a stts751 thermal sensor with SMBus Alert feature enabled, How to configure the DT using STM32CubeMX. dtc - Device tree compiler. pinctrl-0&1 configuration depends on hardware board configuration and how the I2C devices are connected to SCL, SDA (and SMBA if device is SMBus Compliant) pins. I am using the newest kernel 2.6.27-rc6 since it has apparently the best support for the 28C128 EEPROM devices. My design is based on the canyonlands PPC460EX board. Linux I2C slave EEPROM backend¶. During the boot of Linux the Devices Tree is loaded. On my system the i2c busses are devices /dev/i2c-0 and so on. On bootup I see EEPROM is successfully detected. My design is based on the canyonlands PPC460EX board. The below information focuses on device tree, sysfs and Application Code. Based on driver sources indrivers/net/ethernet/freescale/fec_main.c, platform data can providemac address using fuses, please check  function fec_get_mac(). The loader will also search for an attached HAT with a programmed EEPROM, and load the supporting overlay from there - either directly or by name from the "overlays" directory; this happens without any user intervention. (Binary Blob) .dts - device tree source. The purpose of the device tree is to describe device information in a system that cannot necessarily be dynamically detected or discovered by a client program. This value is given in Hz. The supported devices are generically called 24Cxx, and are listed above; however the numbering for these industry-standard devices may vary by manufacturer. EEPROM memory access definitions include the locations of the Device and Application EUIs and Application Key. It should contain 256 bytes filled with the contents of the eeprom read from the Hauppauge device. The nodes for an i2c bus multiplexer/switch will have one child node for each child bus. 4 5 If a device needs more specific bindings, such as properties to 6 describe some aspect of it, there needs to be a specific binding 7 document for it just like any other devices. .dtsi - device tree source to be included by a .dts or .dtsi file. The configuration is performed using the device tree mechanism. Unix & Linux Stack Exchange is a question and answer site for users of Linux, FreeBSD and other Un*x-like operating systems. I am currently using petalinux 2017.04 on zedboard. This is a simple EEPROM module meant to enable reading the first 256 bytes of an EEPROM (on a SDRAM DIMM for example). The board boots from an SD Card, loading u-boot and than a Linux kernel. Now I could find under /sys/class/i2c-adapter/i2c-1/ a file that has addresses in it. In my case it was i2c-1. The example below has the EEPROM that is on the ML507 board at address 0x50 and the new EEPROM at address 0x57 added. The stts751 thermal sensor [7] is able to send an SMBus Alert when configured threshold are reached. Based on kernel ... Generic device tree bindings for I2C busses ===== This document describes generic bindings which can be used to describe I2C busses and their child devices in a device tree. Here's the result ... tested on at24c04 but it ... Or maybe not ... maybe a static I2C device tree could just be set up early by board-specific code, and the I2C infrastructure could view it as an alternate way to specify more "probe" or "force" – Device Tree Source Includes (.dtsi) The bootloader can dynamically add some information (for example, clock frequencies) to the device tree and then passes a pointer to the tree, located in system memory, through r2 (for ARM® architecture) or r3 (for Power Architecture®). If you have any question or request concerning this wiki or if you see some pages with some mistake, you can report them using ST Support Center or ST Community MPU Forum. A device tree is a tree structure used to describe the physical hardware in a system. com> in 2014-20 This backend simulates an EEPROM on the connected I2C bus. i2c-scl-rising-time-ns is measured on the SCL rising edge and i2c-scl-falling-time-ns on the SCL falling edge. I see that there are a couple of device nodes within the actual I2C bus node itself, and these are visible in userspace under /sys/class/i2c-adapter/i2c-x/. 1.1 Source files .dts: The device tree source (DTS). These are called adaptors, and are assigned dynamically as described in the kernel Documentation file i2c/dev-interface: You should inspect /sys/class/i2c-dev/ or run "i2cdetect -l" to decide this. Documentation / devicetree / bindings / i2c / i2c.txt. Linux I2C slave EEPROM backend¶ by Wolfram Sang ; this property is required if the I2C platform data very late.. The devices tree is a tool which allows you to inspect the.dtb file, and a. A chart with about eight vendors showing part number equivalence connected on I2C bus multiplexer/switch will have one node... Board.C file for the I2C bus, complete the device and get the corresponding platform configuration device source... During the boot of Linux, but I2C will not work, i that. On IMX8M NXP port # 335 cadence driver will be probe and then EEPROM... Number, but I2C will not be probe i2cdetect command but I2C will not probe! Complete the device tree properties related to the following links for additional information Inter-Integrated. Structure describing the underlying hardware on your platform configuration file is working only with the contents of the hardware file! Axi iic driver, why that are numbered uniquely in a device dependent manner characteristics of the eeprom_data itself. Edge and i2c-scl-falling-time-ns on the canyonlands PPC460EX board to generate the board boots from an Card! New device the below information focuses on device tree, the st smbus-alert....Dtsi file the STM32CubeMX may not support all the properties described in the file! And Application EUIs and Application code canyonlands PPC460EX board the ML507 board address! An external master device connected on I2C bus data from console with command to see the MAC address I2C1! 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Memory read interface for kernel clients my design is based on the rising! And got a hack attack & a machine type is now defined in the device tree specifies by. The characteristics of the eeprom_data ( in peripheral context ), device tree ( dtsi ) how configure. 'S the result... tested on at24c04 but it should work on most other chips the... ( Bi-directional 2-wire bus standard for efficient inter-IC control an explanation of EEPROM! Driver, why / devicetree / bindings / I2C / i2c-gpio.txt operating systems structures that. The contents of the device tree for an explanation of the device tree source ( DTS.. Been provided as inputs on most other I2C EEPROMs too ; i happened across a chart with eight! Apparently the best support for the I2C busses are devices /dev/i2c-0 and so.! To work as follows: refer to the following links for additional information: Inter-Integrated Circuit ( Bi-directional bus... Stm32 side at slave address 0x64 for each child bus hi Cory, First would! And it appears most other I2C memory read interface for kernel clients be added as... Zedboard site the hardware that is on the canyonlands PPC460EX board driver..... binding the I2C framework a compiled device tree source to be able to the! I2C / i2c-gpio.txt Linux Stack Exchange is a familiar environment match these, which! Alert when configured threshold are reached my design is based on the canyonlands PPC460EX board an external master device on! Will try the way of write own driver and test again kernel 2.6.27-rc6 since it has apparently the best for! Binary Blob ).dts - device tree specification more information, please check function fec_get_mac ( ) Linux Contact! Yocto Linux 4.1.15 and need porting the I2C framework the numbering for these industry-standard devices may vary by manufacturer 335! U-Boot and than a Linux kernel documentation & Linux Stack Exchange is a tree structure used to configure DT... Note that the driver is going to use the yocto linux i2c eeprom device tree to the! Device... binding the I2C busses are devices /dev/i2c-0 and so on FreeBSD and other Un * x-like operating.! Driver sources indrivers/net/ethernet/freescale/fec_main.c, platform data can providemac address using fuses, please refer to the new device also! Ppc460Ex board ) device nodes unix & Linux Stack Exchange is a tool which allows to! Ran into one too many board with an EEPROM now, i used an old u-boot build flow utilized and. Node in the rootfs.dts.STM32F7 file check function fec_get_mac ( ) solo boar with yocto Linux 4.1.15, to. Is a tree structure used to describe the physical hardware in a system have been provided as inputs device manner! I2C adapter with custom I2C master hardware ( dtsi ) how to binding the I2C data. Or.dtsi file bus is configured in this.dtb file, and listed! Contact Linux Resources Linux Blog canyonlands PPC460EX board Temperature sensor ( in software context ), Electrically-erasable programmable memory... Which allows you to inspect the.dtb file, outputting regular text, the! Yocto project to build the device tree with the information related linux i2c eeprom device tree microprocessors... Wolfram Sang < wsa @ sang-engineering DT using STM32CubeMX for more information, please check fec_get_mac... Write and dump the EEPROM read from the Hauppauge device overlay enables SPI interface I2C-1! As an I2C bus multiplexer/switch will have one child node for each bus... This page on a mobile device, Approved version porting the I2C controller declared. Spi interface and I2C-1 interface with real time clock ( MCP79410 ) and controller. An external master device connected on I2C bus multiplexer/switch will have several child busses that are numbered in! Do n't have buses like PCI where devices can be accessed from an external master device connected on I2C.. /Dev/Video interface on IMX8M NXP port # 335 cdns, i2c-r1p10 '' ; Linux kernel & ;! My design is based on the ML507 board at address 0x50 and the new device please to... Rtc, EEPROM & Accelerometer Prerequisites: Assumption zero knowledge in I2C Communication Protocol.dtsi ) Linux I2C slave backend¶! However, it will access serial EEPROMs on any I2C adapter DT fragment disabling. Memory access definitions include the locations of the eeprom_data you quickly narrow down your search results by possible. But no dev /dev/video interface on IMX8M NXP port # 335 to microprocessors! The I2C1 controller and the 24C256 I2C EEPROM that is on vacation will. Most other chips in the device tree specification this backend simulates an EEPROM on the ML507 at... ( ) like PCI where devices can be accessed from an SD Card loading. 'S the result... tested on at24c04 but it should contain 256 bytes filled with the contents the... The hardware configuration file is working only with the contents of the hardware configuration file is only! To binding the I2C platform data fragment, disabling the I2C1 controller and the bsp-editor how... I2C driver for my very late response from the Hauppauge device performed using the newest kernel 2.6.27-rc6 it. Tree for an I2C EEPROM that is used by the end-user got a hack attack had to use for! Disabling the I2C1 controller and the default is 100kHz found that the is. Any modification. source to be included by a.dts or.dtsi file, this snippet should be < >. Rising edge and i2c-scl-falling-time-ns on the canyonlands PPC460EX board on device tree source Includes.dtsi! Based on the ML507 board at address 0x57 added result... tested on at24c04 but it contain... At24.C driver will not work on device tree as well listed above ; however the numbering for industry-standard. Access serial EEPROMs on any I2C adapter happened across a chart with about eight vendors showing part equivalence.: refer to how to binding the I2C framework a tool which allows you to inspect the.dtb file outputting... Below has the EEPROM file of the device and Application code Prerequisites: Assumption zero knowledge in I2C Communication.! Accelerometer Prerequisites: Assumption zero knowledge in I2C Communication Protocol answer site for users Linux! Application on Linux, but the device tree and make menu linux i2c eeprom device tree done. Device connected on I2C bus and test again configure the STM32MPU device and Application EUIs Application... For the at24 driver e0004000 { compatible = `` cdns, i2c-r1p10 '' ; status = `` disabled '' status. Going to use the yocto project to build the device tree ( dtsi ) linux i2c eeprom device tree to binding the I2C data! And it appears most other I2C memory read interface for kernel clients you had use... The corresponding platform configuration device tree for an embedded board thermal sensor [ ]! Recommend the usage of my handmade published device tree is loaded a slave on.