This is selected sections of the current manual for fmc-bus, as developed outside of the kernel before submission. Signed-off-by: Alessandro Rubini <rubini@xxxxxxxxx> Acked-by: Juan David Gonzalez Cobas <dcobas@xxxxxxx> Acked-by: Emilio G. Cota <cota@xxxxxxxxx> Acked-by: Samuel Iglesias Gonsalvez <siglesias@xxxxxxxxxx> --- Documentation/00-INDEX | 2 + Documentation/fmc/00-INDEX | 26 +++ Documentation/fmc/API.txt | 44 +++++ Documentation/fmc/FMC-and-SDB.txt | 89 +++++++++++ Documentation/fmc/carrier.txt | 311 +++++++++++++++++++++++++++++++++++++ Documentation/fmc/identifiers.txt | 169 ++++++++++++++++++++ Documentation/fmc/mezzanine.txt | 123 +++++++++++++++ Documentation/fmc/parameters.txt | 56 +++++++ 8 files changed, 820 insertions(+), 0 deletions(-) create mode 100644 Documentation/fmc/00-INDEX create mode 100644 Documentation/fmc/API.txt create mode 100644 Documentation/fmc/FMC-and-SDB.txt create mode 100644 Documentation/fmc/carrier.txt create mode 100644 Documentation/fmc/identifiers.txt create mode 100644 Documentation/fmc/mezzanine.txt create mode 100644 Documentation/fmc/parameters.txt diff --git a/Documentation/00-INDEX b/Documentation/00-INDEX index 45b3df9..0c4cc68 100644 --- a/Documentation/00-INDEX +++ b/Documentation/00-INDEX @@ -187,6 +187,8 @@ firmware_class/ - request_firmware() hotplug interface info. flexible-arrays.txt - how to make use of flexible sized arrays in linux +fmc/ + - information about the FMC bus abstraction frv/ - Fujitsu FR-V Linux documentation. futex-requeue-pi.txt diff --git a/Documentation/fmc/00-INDEX b/Documentation/fmc/00-INDEX new file mode 100644 index 0000000..71304b7 --- /dev/null +++ b/Documentation/fmc/00-INDEX @@ -0,0 +1,26 @@ + +Documentation in this directory comes from sections of the manual we +wrote for the externally-developed fmc-bus package. The complete +manual as of today (2013-02) is available in PDF format at +http://www.ohwr.org/projects/fmc-bus/files + +00-INDEX + - this file. + +FMC-and-SDB.txt + - What are FMC and SDB, basic concepts for this framework + +API.txt + - The functions that are exported by the bus driver + +parameters.txt + - The module parameters + +carrier.txt + - writing a carrier (a device) + +mezzanine.txt + - writing code for your mezzanine (a driver) + +identifiers.txt + - how identification and matching works diff --git a/Documentation/fmc/API.txt b/Documentation/fmc/API.txt new file mode 100644 index 0000000..2fe75d6 --- /dev/null +++ b/Documentation/fmc/API.txt @@ -0,0 +1,44 @@ +Functions Exported by fmc.ko +**************************** + +The FMC core exports the usual 4 functions that are needed for a bus to +work, and a few more: + + int fmc_driver_register(struct fmc_driver *drv); + void fmc_driver_unregister(struct fmc_driver *drv); + int fmc_device_register(struct fmc_device *fmc); + void fmc_device_unregister(struct fmc_device *fmc); + + int fmc_device_register_n(struct fmc_device *fmc, int n); + void fmc_device_unregister_n(struct fmc_device *fmc, int n); + + uint32_t fmc_readl(struct fmc_device *fmc, int offset); + void fmc_writel(struct fmc_device *fmc, uint32_t val, int off); + void *fmc_get_drvdata(struct fmc_device *fmc); + void fmc_set_drvdata(struct fmc_device *fmc, void *data); + + int fmc_reprogram(struct fmc_device *f, struct fmc_driver *d, char *gw, + int sdb_entry); + +The data structure that describe a device is detailed in *note FMC +Device::, the one that describes a driver is detailed in *note FMC +Driver::. + +The functions to register and unregister n devices are meant to be used +by carriers that host more than one mezzanine. The devices must be all +registered at the same time because if the FPGA is reprogrammed, all +devices in the array are affected. Usually, the driver matching the +first device will reprogram the FPGA, so other devices must know they +are already driven by a reprogrammed FPGA. + +If a carrier hosts slots that are driven by different FPGA devices, it +should register as a group only mezzanines that are driven by the same +FPGA, for the reason outlined above. + +Finally, the fmc_reprogram function calls the reprogram method (see +*note The API Offered by Carriers:: and also scans the memory area for +an SDB tree. You can pass -1 as sdb_entry to disable such scan. +Otherwise, the function fails if no tree is found at the specified +entry point. The function is meant to factorize common code, and by +the time you read this it is already used by the spec-sw and fine-delay +modules. diff --git a/Documentation/fmc/FMC-and-SDB.txt b/Documentation/fmc/FMC-and-SDB.txt new file mode 100644 index 0000000..bf49e0b --- /dev/null +++ b/Documentation/fmc/FMC-and-SDB.txt @@ -0,0 +1,89 @@ + +FMC (FPGA Mezzanine Card) is the standard we use for our I/O devices, +in the context of White Rabbit and related hardware. + +In our I/O environments we need to write drivers for each mezzanine +card, and such drivers must work regardless of the carrier being used. +To achieve this, we abstract the FMC interface. + +We have a carrier for PCI-E called SPEC and one for VME called SVEC, +but more are planned. Also, we support stand-alone devices (usually +plugged on a SPEC card), controlled through Etherbone, developed by GSI. + +Code and documentation for the FMC bus was born as part of the spec-sw +project, but now it lives in its own project. Other projects, i.e. +software support for the various carriers, should include this as a +submodule. + +The most up to date version of code and documentation is always +available from the repository you can clone from: + + git://ohwr.org/fmc-projects/fmc-bus.git (read-only) + git@xxxxxxxx:fmc-projects/fmc-bus.git (read-write for developers) + +Selected versions of the documentation, as well as complete tar +archives for selected revisions are placed to the Files section of the +project: `http://www.ohwr.org/projects/fmc-bus/files' + + +What is FMC +*********** + +FMC, as said, stands for "FPGA Mezzanine Card". It is a standard +developed by the VME consortium called VITA (VMEbus International Trade +Association and ratified by ANSI, the American National Standard +Institute. The official documentation is called "ANSI-VITA 57.1". + +The FMC card is an almost square PCB, around 70x75 millimeters, that is +called mezzanine in this document. It usually lives plugged into +another PCB for power supply and control; such bigger circuit board is +called carrier from now on, and a single carrier may host more than one +mezzanine. + +In the typical application the mezzanine is mostly analog while the +carrier is mostly digital, and hosts an FPGA that must be configured to +match the specific mezzanine and the desired application. Thus, you may +need to load different FPGA images to drive different instances of the +same mezzanine. + +FMC, as such, is not a bus in the usual meaning of the term, because +most carriers have only one connector, and carriers with several +connectors have completely separate electrical connections to them. +This package, however, implements a bus as a software abstraction. + + +What is SDB +*********** + +SDB (Self Describing Bus) is a set of data structures that we use for +enumerating the internal structure of an FPGA image. We also use it as +a filesystem inside the FMC EEPROM. + +SDB is not mandatory for use of this FMC kernel bus, but if you have SDB +this package can make good use of it. SDB itself is developed in the +fpga-config-space OHWR project. The link to the repository is +`git://ohwr.org/hdl-core-lib/fpga-config-space.git' and what is used in +this project lives in the sdbfs subdirectory in there. + +SDB support for FMC is described in *note FMC Identification:: and +*note SDB Support:: + + +SDB Support +*********** + +The fmc.ko bus driver exports a few functions to help drivers taking +advantage of the SDB information that may be present in your own FPGA +memory image. + +The module exports the following functions, in the special header +<linux/fmc-sdb.h>. The linux/ prefix in the name is there because we +plan to submit it upstream in the future, and don't want to force +changes on our drivers if that happens. + + int fmc_scan_sdb_tree(struct fmc_device *fmc, unsigned long address); + void fmc_show_sdb_tree(struct fmc_device *fmc); + signed long fmc_find_sdb_device(struct sdb_array *tree, uint64_t vendor, + uint32_t device, unsigned long *sz); + int fmc_free_sdb_tree(struct fmc_device *fmc); + diff --git a/Documentation/fmc/carrier.txt b/Documentation/fmc/carrier.txt new file mode 100644 index 0000000..4694755 --- /dev/null +++ b/Documentation/fmc/carrier.txt @@ -0,0 +1,311 @@ +FMC Device +********** + +Within the Linux bus framework, the FMC device is created and +registered by the carrier driver. For example, the PCI driver for the +SPEC card fills a data structure for each SPEC that it drives, and +registers an associated FMC device for each card. The SVEC driver can +do exactly the same for the VME carrier (actually, it should do it +twice, because the SVEC carries two FMC mezzanines). Similarly, an +Etherbone driver will be able to register its own FMC devices, offering +communication primitives through frame exchange. + +The contents of the EEPROM within the FMC are used for identification +purposes, i.e. for matching the device with its own driver. For this +reason the device structure includes a complete copy of the EEPROM +(actually, the carrier driver may choose whether or not to return it - +for example we most likely won't have the whole EEPROM available for +Etherbone devices. + +The following listing shows the current structure defining a device. +Please note that all the machinery is in place but some details may +still change in the future. For this reason, there is a version field +at the beginning of the structure. As usual, the minor number will +change for compatible changes (like a new flag) and the major number +will increase when an incompatible change happens (for example, a +change in layout of some fmc data structures). Device writers should +just set it to the value FMC_VERSION, and be ready to get back -EINVAL +at registration time. + + struct fmc_device { + unsigned long version; + unsigned long flags; + struct module *owner; /* char device must pin it */ + struct fmc_fru_id id; /* for EEPROM-based match */ + struct fmc_operations *op; /* carrier-provided */ + int irq; /* according to host bus. 0 == none */ + int eeprom_len; /* Usually 8kB, may be less */ + int eeprom_addr; /* 0x50, 0x52 etc */ + uint8_t *eeprom; /* Full contents or leading part */ + char *carrier_name; /* "SPEC" or similar, for special use */ + void *carrier_data; /* "struct spec *" or equivalent */ + __iomem void *fpga_base; /* May be NULL (Etherbone) */ + __iomem void *slot_base; /* Set by the driver */ + struct fmc_device **devarray; /* Allocated by the bus */ + int slot_id; /* Index in the slot array */ + int nr_slots; /* Number of slots in this carrier */ + unsigned long memlen; /* Used for the char device */ + struct device dev; /* For Linux use */ + struct device *hwdev; /* The underlying hardware device */ + unsigned long sdbfs_entry; + struct sdb_array *sdb; + uint32_t device_id; /* Filled by the device */ + char *mezzanine_name; /* Defaults to ``fmc'' */ + void *mezzanine_data; + }; + +The meaning of most fields is summarized in the code comment above. + +The following fields must be filled by the carrier driver before +registration: + + * version: must be set to FMC_VERSION. + + * owner: set to MODULE_OWNER. + + * op: the operations to act on the device. + + * irq: number for the mezzanine; may be zero. + + * eeprom_len: length of the following array. + + * eeprom_addr: 0x50 for first mezzanine and so on. + + * eeprom: the full content of the I2C EEPROM. + + * carrier_name. + + * carrier_data: a unique pointer for the carrier. + + * fpga_base: the I/O memory address (may be NULL). + + * slot_id: the index of this slot (starting from zero). + + * memlen: if fpga_base is valid, the length of I/O memory. + + * hwdev: to be used in dev_err() calls. + + * device_id: a slot-specific unique integer number. + + +Please note that the carrier should read its own EEPROM memory before +registering the device, as well as fill all other fields listed above. + +The following fields should not be assigned, because they are filled +later by either the bus or the device driver: + + * flags. + + * fru_id: filled by the bus, parsing the eeprom. + + * slot_base: filled and used by the driver, if useful to it. + + * devarray: an array og all mezzanines driven by a singe FPGA. + + * nr_slots: set by the core at registration time. + + * dev: used by Linux. + + * sdb: FPGA contents, scanned according to driver's directions. + + * sdbfs_entry: SDB entry point in EEPROM: autodetected. + + * mezzanine_data: available for the driver. + + * mezzanine_name: filled by fmc-bus during identification. + + +Note: mezzanine_data may be redundant, because Linux offers the drvdata +approach, so the field may be removed in later versions of this bus +implementation. + +As I write this, she SPEC carrier is already completely functional in +the fmc-bus environment, and is a good reference to look at. + + +The API Offered by Carriers +=========================== + +The carrier provides a number of methods by means of the +`fmc_operations' structure, which currently is defined like this +(again, it is a moving target, please refer to the header rather than +this document): + + struct fmc_operations { + uint32_t (*readl)(struct fmc_device *fmc, int offset); + void (*writel)(struct fmc_device *fmc, uint32_t value, int offset); + int (*reprogram)(struct fmc_device *f, struct fmc_driver *d, char *gw); + int (*validate)(struct fmc_device *fmc, struct fmc_driver *drv); + int (*irq_request)(struct fmc_device *fmc, irq_handler_t h, + char *name, int flags); + void (*irq_ack)(struct fmc_device *fmc); + int (*irq_free)(struct fmc_device *fmc); + int (*gpio_config)(struct fmc_device *fmc, struct fmc_gpio *gpio, + int ngpio); + int (*read_ee)(struct fmc_device *fmc, int pos, void *d, int l); + int (*write_ee)(struct fmc_device *fmc, int pos, const void *d, int l); + }; + +The individual methods perform the following tasks: + +`readl' +`writel' + These functions access FPGA registers by whatever means the + carrier offers. They are not expected to fail, and most of the time + they will just make a memory access to the host bus. If the + carrier provides a fpga_base pointer, the driver may use direct + access through that pointer. For this reason the header offers the + inline functions fmc_readl and fmc_writel that access fpga_base if + the respective method is NULL. A driver that wants to be portable + and efficient should use fmc_readl and fmc_writel. For Etherbone, + or other non-local carriers, error-management is still to be + defined. + +`validate' + Module parameters are used to manage different applications for + two or more boards of the same kind. Validation is based on the + busid module parameter, if provided, and returns the matching + index in the associated array. See *note Module Parameters:: in in + doubt. If no match is found, `-ENOENT' is returned; if the user + didn't pass `busid=', all devices will pass validation. The value + returned by the validate method can be used as index into other + parameters (for example, some drivers use the `lm32=' parameter in + this way). Such "generic parameters" are documented in *note + Module Parameters::, below. The validate method is used by + `fmc-trivial.ko', described in *note fmc-trivial::. + +`reprogram' + The carrier enumerates FMC devices by loading a standard (or + golden) FPGA binary that allows EEPROM access. Each driver, then, + will need to reprogram the FPGA by calling this function. If the + name argument is NULL, the carrier should reprogram the golden + binary. If the gateware name has been overridden through module + parameters (in a carrier-specific way) the file loaded will match + the parameters. Per-device gateware names can be specified using + the `gateware=' parameter, see *note Module Parameters::. Note: + Clients should call rhe new helper, fmc_reprogram, which both + calls this method and parse the SDB tree of the FPGA. + +`irq_request' +`irq_ack' +`irq_free' + Interrupt management is carrier-specific, so it is abstracted as + operations. The interrupt number is listed in the device + structure, and for the mezzanine driver the number is only + informative. The handler will receive the fmc pointer as dev_id; + the flags argument is passed to the Linux request_irq function, + but fmc-specific flags may be added in the future. You'll most + likely want to pass the `IRQF_SHARED' flag. + +`gpio_config' + The method allows to configure a GPIO pin in the carrier, and read + its current value if it is configured as input. See *note The GPIO + Abstraction:: for details. + +`read_ee' +`write_ee' + Read or write the EEPROM. The functions are expected to be only + called before reprogramming and the carrier should refuse them + with `ENODEV' after reprogramming. The offset is expected to be + within 8kB (the current size), but addresses up to 1MB are + reserved to fit bigger I2C devices in the future. Carriers may + offer access to other internal flash memories using these same + methods: for example the SPEC driver may define that its carrier + I2C memory is seen at offset 1M and the internal SPI flash is seen + at offset 16M. This multiplexing of several flash memories in the + same address space is is carrier-specific and should only be used + by a driver that has verified the `carrier_name' field. + + + +The GPIO Abstraction +==================== + +Support for GPIO pins in the fmc-bus environment is not very +straightforward and deserves special discussion. + +While the general idea of a carrier-independent driver seems to fly, +configuration of specific signals within the carrier needs at least +some knowledge of the carrier itself. For this reason, the specific +driver can request to configure carrier-specific GPIO pins, numbered +from 0 to at most 4095. Configuration is performed by passing a +pointer to an array of struct fmc_gpio items, as well as the length of +the array. This is the data structure: + + struct fmc_gpio { + char *carrier_name; + int gpio; + int _gpio; /* internal use by the carrier */ + int mode; /* GPIOF_DIR_OUT etc, from <linux/gpio.h> */ + int irqmode; /* IRQF_TRIGGER_LOW and so on */ + }; + +By specifying a carrier_name for each pin, the driver may access +different pins in different carriers. The gpio_config method is +expected to return the number of pins successfully configured, ignoring +requests for other carriers. However, if no pin is configured (because +no structure at all refers to the current carrier_name), the operation +returns an error so the caller will know that it is running under a +yet-unsupported carrier. + +So, for example, a driver that has been developed and tested on both +the SPEC and the SVEC may request configuration of two different GPIO +pins, and expect one such configuration to succeed - if none succeeds +it most likely means that the current carrier is a still-unknown one. + +If, however, your GPIO pin has a specific known role, you can pass a +special number in the gpio field, using one of the following macros: + + #define FMC_GPIO_RAW(x) (x) /* 4096 of them */ + #define FMC_GPIO_IRQ(x) ((x) + 0x1000) /* 256 of them */ + #define FMC_GPIO_LED(x) ((x) + 0x1100) /* 256 of them */ + #define FMC_GPIO_KEY(x) ((x) + 0x1200) /* 256 of them */ + #define FMC_GPIO_TP(x) ((x) + 0x1300) /* 256 of them */ + #define FMC_GPIO_USER(x) ((x) + 0x1400) /* 256 of them */ + +Use of virtual GPIO numbers (anything but FMC_GPIO_RAW) is allowed +provided the carrier_name field in the data structure is left +unspecified (NULL). Each carrier is responsible for providing a mapping +between virtual and physical GPIO numbers. The carrier may then use the +_gpio field to cache the result of this mapping. + +All carriers must map their I/O lines to the sets above starting from +zero. The SPEC, for example, maps interrupt pins 0 and 1, and test +points 0 through 3 (even if the test points on the PCB are called +5,6,7,8). + +If, for example, a driver requires a free LED and a test point (for a +scope probe to be plugged at some point during development) it may ask +for FMC_GPIO_LED(0) and FMC_GPIO_TP(0). Each carrier will provide +suitable GPIO pins. Clearly, the person running the drivers will know +the order used by the specific carrier driver in assigning leds and +testpoints, so to make a carrier-dependent use of the diagnostic tools. + +In theory, some form of autodetection should be possible: a driver like +the wr-nic (which uses IRQ(1) on the SPEC card) should configure +IRQ(0), make a test with software-generated interrupts and configure +IRQ(1) if the test fails. This probing step should be used because even +if the wr-nic gateware is known to use IRQ1 on the SPEC, the driver +should be carrier-independent and thus use IRQ(0) as a first bet - +actually, the knowledge that IRQ0 may fail is carrier-dependent +information, but using it doesn't make the driver unsuitable for other +carriers. + +The return value of gpio_config is defined as follows: + + * If no pin in the array can be used by the carrier, `-ENODEV'. + + * If at least one virtual GPIO number cannot be mapped, `-ENOENT'. + + * On success, 0 or positive. The value returned is the number of + high input bits (if no input is configured, the value for success + is 0). + +While I admit the procedure is not completely straightforward, it +allows configuration, input and output with a single carrier operation. +Given the typical use case of FMC devices, GPIO operations are not +expected to ever by in hot paths, and GPIO access so fare has only been +used to configure the interrupt pin, mode and polarity. Especially +reading inputs is not expected to be common. If your device has GPIO +capabilities in the hot path, you should consider using the kernel's +GPIO mechanisms. diff --git a/Documentation/fmc/identifiers.txt b/Documentation/fmc/identifiers.txt new file mode 100644 index 0000000..8cf5c9a --- /dev/null +++ b/Documentation/fmc/identifiers.txt @@ -0,0 +1,169 @@ +FMC Identification +****************** + +The FMC standard requires every compliant mezzanine to carry +identification information in an I2C EEPROM. The information must be +laid out according to the "IPMI Platform Management FRU Information", +where IPMI is a lie I'd better not expand, and FRU means "Field +Replaceable Unit". + +The FRU information is an intricate unreadable binary blob that must +live at offset 0 of the EEPROM, and typically extends for a few hundred +bytes. The standard allows the application to use all the remaining +storage area of the EEPROM as it wants. + +This chapter explains how to create your own EEPROM image and how to +write it in your mezzanine, as well as how devices and drivers are +paired at run time. EEPROM programming uses tools that are part of this +package and SDB (part of the fpga-config-space package). + +The first sections are only interesting for manufacturers who need to +write the EEPROM. If you are just a software developer writing an FMC +device or driver, you may jump straight to *note How Identification +Works at Run Time::. + + +Building the FRU Structure +========================== + +If you want to know the internals of the FRU structure and despair, you +can retrieve the document from +`http://download.intel.com/design/servers/ipmi/FRU1011.pdf' . The +standard is awful and difficult without reason, so we only support the +minimum mandatory subset - we create a simple structure and parse it +back at run time, but we are not able to either generate or parse more +arcane features like non-english languages and 6-bit text. If you need +more items of the FRU standard for you boards, please submit patches. + +This package includes the Python script that Matthieu Cattin wrote to +generate the FRU binary blob, based on an helper libipmi by Manohar +Vanga and Matthieu himself. I changed the test script to receive +parameters from the command line or from the environment (the command +line takes precedence) + +To make a long story short, in order to build a standard-compliant +binary file to be burned in your EEPROM, you need the following items: + + Environment Opt Official Name Default +--------------------------------------------------------------------- + FRU_VENDOR -v "Board Manufacturer" fmc-example + FRU_NAME -n "Board Product Name" mezzanine + FRU_SERIAL -s `Board Serial Number" 0001 + FRU_PART -p "Board Part Number" sample-part + FRU_OUTPUT -o not applicable /dev/stdout + +The "Official Name" above is what you find in the FRU official +documentation, chapter 11, page 7 ("Board Info Area Format"). The +output option is used to save the generated binary to a specific file +name instead of stdout. + +You can pass the items to the FRU generator either in the environment +or on the command line. This package has currently no support for +specifying power consumption or such stuff, but I plan to add it as +soon as I find some time for that. + +FIXME: consumption etc for FRU are here or in PTS? + +The following example creates a binary image for a specific board: + + ./tools/fru-generator -v CERN -n FmcAdc100m14b4cha \ + -s HCCFFIA___-CR000003 -p EDA-02063-V5-0 > eeprom.bin + +The following example shows a script that builds several binary EEPROM +images for a series of boards, changing the serial number for each of +them. The script uses a mix of environment variables and command line +options, and uses the same string patterns shown above. + + #!/bin/sh + + export FRU_VENDOR="CERN" + export FRU_NAME="FmcAdc100m14b4cha" + export FRU_PART="EDA-02063-V5-0" + + serial="HCCFFIA___-CR" + + for number in $(seq 1 50); do + # build number-string "ns" + ns="$(printf %06d $number)" + ./fru-generator -s "${serial}${ns}" > eeprom-${ns}.bin + done + + +Using SDB-FS in the EEPROM +========================== + +If you want to use SDB as a filesystem in the EEPROM device within the +mezzanine, you should create one such filesystem using gensdbfs, from +the fpga-config-space package on OHWR. + +By using an SBD filesystem you can cluster several files in a single +EEPROM, so both the host system and a soft-core running in the FPGA (if +any) can access extra production-time information. + +We chose to use SDB as a storage filesystem because the format is very +simple, and both the host system and the soft-core will likely already +include support code for such format. The SDB library offered by the +fpga-config-space is less than 1kB under LM32, so it proves quite up to +the task. + +The SDB entry point (which acts as a directory listing) cannot live at +offset zero in the flash device, because the FRU information must live +there. To avoid wasting precious storage space while still allowing +for more-than-minimal FRU structures, the fmc.ko will look for the SDB +record at address 256, 512 and 1024. + +In order to generate the complete EEPROM image you'll need a +configuration file for gensdbfs: you tell the program where to place +the sdb entry point, and you must force the FRU data file to be placed +at the beginning of the storage device. If needed, you can also place +other files at a special offset (we sometimes do it for backward +compatibility with drivers we wrote before implementing SDB for flash +memory). + +The directory tools/sdbfs of this package includes a well-commented +example that you may want to use as a starting point (the comments are +in the file called -SDB-CONFIG-). Reading documentation for gensdbfs +is a suggested first step anyways. + +This package (generic FMC bus support) only accesses two files in the +EEPROM: the FRU information, at offset zero, with a suggested filename +of IPMI-FRU and the short name for the mezzanine, in a file called +name. The IPMI-FRU name is not mandatory, but a strongly suggested +choice; the name filename is mandatory, because this is the preferred +short name used by the FMC core. For example, a name of "fdelay" may +supplement a Product Name like "FmcDelay1ns4cha" - exactly as +demonstrated in `tools/sdbfs'. + +Note: SDB access to flash memory is not yet supported, so the short +name currently in use is just the "Product Name" FRU string. + +The example in tools/sdbfs includes an extra file, that is needed by +the fine-delay driver, and must live at a known address of 0x1800. By +running gensdbfs on that directory you can output your binary EEPROM +image (here below spusa$ is the shell prompt): + + spusa$ ../fru-generator -v CERN -n FmcDelay1ns4cha -s proto-0 \ + -p EDA-02267-V3 > IPMI-FRU + spusa$ ls -l + total 16 + -rw-rw-r-- 1 rubini staff 975 Nov 19 18:08 --SDB-CONFIG-- + -rw-rw-r-- 1 rubini staff 216 Nov 19 18:13 IPMI-FRU + -rw-rw-r-- 1 rubini staff 11 Nov 19 18:04 fd-calib + -rw-rw-r-- 1 rubini staff 7 Nov 19 18:04 name + spusa$ sudo gensdbfs . /lib/firmware/fdelay-eeprom.bin + spusa$ sdb-read -l -e 0x100 /lib/firmware/fdelay-eeprom.bin + /home/rubini/wip/sdbfs/userspace/sdb-read: listing format is to be defined + 46696c6544617461:2e202020 00000100-000018ff . + 46696c6544617461:6e616d65 00000200-00000206 name + 46696c6544617461:66642d63 00001800-000018ff fd-calib + 46696c6544617461:49504d49 00000000-000000d7 IPMI-FRU + spusa$ ../fru-dump /lib/firmware/fdelay-eeprom.bin + /lib/firmware/fdelay-eeprom.bin: manufacturer: CERN + /lib/firmware/fdelay-eeprom.bin: product-name: FmcDelay1ns4cha + /lib/firmware/fdelay-eeprom.bin: serial-number: proto-0 + /lib/firmware/fdelay-eeprom.bin: part-number: EDA-02267-V3 + +As expected, the output file is both a proper sdbfs object and an IPMI +FRU information blob. The fd-calib file lives at offset 0x1800 and is +over-allocated to 256 bytes, according to the configuration file for +gensdbfs. diff --git a/Documentation/fmc/mezzanine.txt b/Documentation/fmc/mezzanine.txt new file mode 100644 index 0000000..87910db --- /dev/null +++ b/Documentation/fmc/mezzanine.txt @@ -0,0 +1,123 @@ +FMC Driver +********** + +An FMC driver is concerned with the specific mezzanine and associated +gateware. As such, it is expected to be independent of the carrier +being used: it will perform I/O accesses only by means of +carrier-provided functions. + +The matching between device and driver is based on the content of the +EEPROM (as mandated by the FMC standard) or by the actual cores +configured in the FPGA; the latter technique is used when the FPGA is +already programmed when the device is registered to the bus core. + +In some special cases it is possible for a driver to directly access +FPGA registers, by means of the `fpga_base' field of the device +structure. This may be needed for high-bandwidth peripherals like fast +ADC cards. If the device module registered a remote device (for example +by means of Etherbone), the `fpga_base' pointer will be NULL. +Therefore, drivers must be ready to deal with NULL base pointers, and +fail gracefully. Most driver, however, are not expected to access the +pointer directly but run fmc_readl and fmc_writel instead, which will +work in any case. + +In even more special cases, the driver may access carrier-specific +functionality: the `carrier_name' string allows the driver to check +which is the current carrier and make use of the `carrier_data' +pointer. We chose to use carrier names rather than numeric identifiers +for greater flexibility, but also to avoid a central registry within +the `fmc.h' file - we hope other users will exploit our framework with +their own carriers. An example use of carrier names is in GPIO setup +(see *note The GPIO Abstraction::), although the name match is not +expected to be performed by the driver. If you depend on specific +carriers, please check the carrier name and fail gracefully if your +driver finds it is running in a yet-unknown-to-it environment. + + +ID Table +======== + +Like most other Linux drivers, and FMC driver must list all the devices +which it is able to drive. This is usually done by means of a device +table, but in FMC we can match hardware based either on the contents of +their EEPROM or on the actual FPGA cores that can be enumerated. +Therefore, we have two tables of identifiers. + +Matching of FRU information depends on two names, the manufacturer (or +vendor) and the device (see *note FMC Identification::); for +flexibility during production (i.e. before writing to the EEPROM) the +bus supports a catch-all driver that specifies NULL strings. For this +reason, the table is specified as pointer-and-length, not a a +null-terminated array - the entry with NULL names can be a valid entry. + +Matching on FPGA cores depends on two numeric fields: the 64-bit vendor +number and the 32-bit device number. Support for matching based on +class is not yet implemented. Each device is expected to be uniquely +identified by an array of cores (it matches if all of the cores are +instantiated), and for consistency the list is passed as +pointer-and-length. Several similar devices can be driven by the same +driver, and thus the driver specifies and array of such arrays. + +The complete set of involved data structures is thus the following: + + struct fmc_fru_id { char *manufacturer; char *product_name; }; + struct fmc_sdb_one_id { uint64_t vendor; uint32_t device; }; + struct fmc_sdb_id { struct fmc_sdb_one_id *cores; int cores_nr; }; + + struct fmc_device_id { + struct fmc_fru_id *fru_id; int fru_id_nr; + struct fmc_sdb_id *sdb_id; int sdb_id_nr; + }; + +A better reference, with full explanation, is the <linux/fmc.h> header. + + +Module Parameters +================= + +Most of the FMC drivers need the same set of kernel parameters. This +package includes support to implement common parameters by means of +fields in the `fmc_driver' structure and simple macro definitions. + +The parameters are carrier-specific, in that they rely on the busid +concept, that varies among carriers. For the SPEC, the identifier is a +PCI bus and devfn number, 16 bits wide in total; drivers for other +carriers will most likely offer something similar but not identical, +and some code duplication is unavoidable. + +This is the list of parameters that are common to several modules to +see how they are actually used, please look at spec-trivial.c. + +`busid=' + This is an array of integers, listing carrier-specific + identification numbers. For PIC, for example, `0x0400' represents + bus 4, slot 0. If any such ID is specified, the driver will only + accept to drive cards that appear in the list (even if the FMC ID + matches). This is accomplished by the validate carrier method. + +`gateware=' + The argument is an array of strings. If no busid= is specified, + the first string of gateware= is used for all cards; otherwise the + identifiers and gateware names are paired one by one, in the order + specified. + +`show_sdb=' + For modules supporting it, this parameter asks to show the SDB + internal structure by means of kernel messages. It is disabled by + default because those lines tend to hide more important messages, + if you look at the system console while loading the drivers. + Note: the parameter is being obsoleted, because fmc.ko itself now + supports dump_sdb= that applies to every client driver. + + +For example, if you are using the trivial driver to load two different +gateware files to two different cards, you can use the following +parameters to load different binaries to the cards, after looking up +the PCI identifiers. This has been tested with a SPEC carrier. + + insmod fmc-trivial.ko \ + busid=0x0200,0x0400 \ + gateware=fmc/fine-delay.bin,fmc/simple-dio.bin + +Please note that not all sub-modules support all of those parameters. +You can use modinfo to check what is supported by each module. diff --git a/Documentation/fmc/parameters.txt b/Documentation/fmc/parameters.txt new file mode 100644 index 0000000..59edf08 --- /dev/null +++ b/Documentation/fmc/parameters.txt @@ -0,0 +1,56 @@ +Module Parameters in fmc.ko +*************************** + +The core driver receives two module parameters, meant to help debugging +client modules. Both parameters can be modified by writing to +/sys/module/fmc/parameters/, because they are used when client drivers +are devices are registered, not when fmc.ko is loaded. + +`dump_eeprom=' + If not zero, the parameter asks the bus controller to dump the + EEPROM of any device that is registered, using printk. + +`dump_sdb=' + If not zero, the parameter prints the SDB tree of every FPGA it is + loaded by fmc_reprogram(). If greater than one, it asks to dump + the binary content of SDB records. This currently only dumps the + top-level SDB array, though. + + +EEPROM dumping avoids repeating lines, since most of the contents is +usually empty and all bits are one or zero. This is an example of the +output: + + [ 6625.850480] spec 0000:02:00.0: FPGA programming successful + [ 6626.139949] spec 0000:02:00.0: Manufacturer: CERN + [ 6626.144666] spec 0000:02:00.0: Product name: FmcDelay1ns4cha + [ 6626.150370] FMC: mezzanine 0: 0000:02:00.0 on SPEC + [ 6626.155179] FMC: dumping eeprom 0x2000 (8192) bytes + [ 6626.160087] 0000: 01 00 00 01 00 0b 00 f3 01 0a 00 a5 85 87 c4 43 + [ 6626.167069] 0010: 45 52 4e cf 46 6d 63 44 65 6c 61 79 31 6e 73 34 + [ 6626.174019] 0020: 63 68 61 c7 70 72 6f 74 6f 2d 30 cc 45 44 41 2d + [ 6626.180975] 0030: 30 32 32 36 37 2d 56 33 da 32 30 31 32 2d 31 31 + [...] + [ 6626.371366] 0200: 66 64 65 6c 61 79 0a 00 00 00 00 00 00 00 00 00 + [ 6626.378359] 0210: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + [ 6626.385361] [...] + [ 6626.387308] 1800: 70 6c 61 63 65 68 6f 6c 64 65 72 ff ff ff ff ff + [ 6626.394259] 1810: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff + [ 6626.401250] [...] + +The dump of SDB looks like the following; the example shows the simple +golden gateware for the SPEC card, removing the leading timestamps to +fit the page: + + spec 0000:02:00.0: SDB: 00000651:e6a542c9 WB4-Crossbar-GSI + spec 0000:02:00.0: SDB: 0000ce42:ff07fc47 WR-Periph-Syscon (00000000-000000ff) + FMC: mezzanine 0: 0000:02:00.0 on SPEC + FMC: poor dump of sdb first level: + 0000: 53 44 42 2d 00 02 01 00 00 00 00 00 00 00 00 00 + 0010: 00 00 00 00 00 00 01 ff 00 00 00 00 00 00 06 51 + 0020: e6 a5 42 c9 00 00 00 02 20 12 05 11 57 42 34 2d + 0030: 43 72 6f 73 73 62 61 72 2d 47 53 49 20 20 20 00 + 0040: 00 00 01 01 00 00 00 07 00 00 00 00 00 00 00 00 + 0050: 00 00 00 00 00 00 00 ff 00 00 00 00 00 00 ce 42 + 0060: ff 07 fc 47 00 00 00 01 20 12 03 05 57 52 2d 50 + 0070: 65 72 69 70 68 2d 53 79 73 63 6f 6e 20 20 20 01 -- 1.7.7.2 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
