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Diffstat (limited to 'meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/0055-Documentation-jtag-Add-ABI-documentation.patch')
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1 files changed, 310 insertions, 0 deletions
diff --git a/meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/0055-Documentation-jtag-Add-ABI-documentation.patch b/meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/0055-Documentation-jtag-Add-ABI-documentation.patch new file mode 100644 index 000000000..1e4142035 --- /dev/null +++ b/meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/0055-Documentation-jtag-Add-ABI-documentation.patch @@ -0,0 +1,310 @@ +From d4c55bd4eeb6d9290025fa353d1787f18bca6ade Mon Sep 17 00:00:00 2001 +From: "Corona, Ernesto" <ernesto.corona@intel.com> +Date: Sun, 10 Mar 2019 11:47:40 -0800 +Subject: [PATCH v29 4/6] Documentation: jtag: Add ABI documentation + +Added document that describe the ABI for JTAG class driver + +Signed-off-by: Oleksandr Shamray <oleksandrs@mellanox.com> +Signed-off-by: Corona, Ernesto <ernesto.corona@intel.com> +Acked-by: Arnd Bergmann <arnd@arndb.de> +Cc: Jonathan Corbet <corbet@lwn.net> +Cc: Jiri Pirko <jiri@mellanox.com> +Cc: Vadim Pasternak <vadimp@mellanox.com> +Cc: Steven A Filary <steven.a.filary@intel.com> +Cc: Bryan Hunt <bryan.hunt@intel.com> +--- +v28->v29 +Comments pointed by Steven Filary <steven.a.filary@intel.com> +- Expand bitbang function to accept multiples bitbang operations within a + single JTAG_IOCBITBANG call. It will receive a buffer with TDI and TMS + values and it is expected that driver fills TDO fields with its + corresponding output value for every transaction. + +v27->v28 +Comments pointed by Steven Filary <steven.a.filary@intel.com> +- Replace JTAG_IOCRUNTEST with JTAG_SIOCSTATE adding support for all TAPC + end states in SW mode using a lookup table to navigate across states. +- Add support for simultaneous READ/WRITE transfers(JTAG_READ_WRITE_XFER). +- Support for switching JTAG controller mode between slave and master + mode. +- Setup JTAG controller mode to master only when the driver is opened, + letting other HW to own the JTAG bus when it isn't in use. +- Include JTAG bit bang IOCTL for low level JTAG control usage + (JTAG_IOCBITBANG). + +v26->v27 +v25->v26 +Comments pointed by Randy Dunlap <rdunlap@infradead.org> +- fix spell in ABI documentation + +v24->v25 +Comments pointed by Greg KH <gregkh@linuxfoundation.org> +- Fixed documentation according to new open() behavior + +v23->v24 +v22->v23 +Comments pointed by Randy Dunlap <rdunlap@infradead.org> +- fix spell in ABI doccumentation + +v21->v22 +Comments pointed by Randy Dunlap <rdunlap@infradead.org> +- fix spell in ABI doccumentation + +v20->v21 +Comments pointed by Randy Dunlap <rdunlap@infradead.org> +- Fix JTAG dirver help in Kconfig + +v19->v20 +Comments pointed by Randy Dunlap <rdunlap@infradead.org> +- Fix JTAG doccumentation + +v18->v19 +Pavel Machek <pavel@ucw.cz> +- Added JTAG doccumentation to Documentation/jtag + +v17->v18 +v16->v17 +v15->v16 +v14->v15 +v13->v14 +v12->v13 +v11->v12 Tobias Klauser <tklauser@distanz.ch> +Comments pointed by +- rename /Documentation/ABI/testing/jatg-dev -> jtag-dev +- Typo: s/interfase/interface +v10->v11 +v9->v10 +Fixes added by Oleksandr: +- change jtag-cdev to jtag-dev in documentation +- update KernelVersion and Date in jtag-dev documentation; +v8->v9 +v7->v8 +v6->v7 +Comments pointed by Pavel Machek <pavel@ucw.cz> +- Added jtag-cdev documentation to Documentation/ABI/testing folder +--- + Documentation/ABI/testing/jtag-dev | 23 ++++++ + Documentation/jtag/overview | 27 +++++++ + Documentation/jtag/transactions | 145 +++++++++++++++++++++++++++++++++++++ + 3 files changed, 195 insertions(+) + create mode 100644 Documentation/ABI/testing/jtag-dev + create mode 100644 Documentation/jtag/overview + create mode 100644 Documentation/jtag/transactions + +diff --git a/Documentation/ABI/testing/jtag-dev b/Documentation/ABI/testing/jtag-dev +new file mode 100644 +index 000000000000..423baab18761 +--- /dev/null ++++ b/Documentation/ABI/testing/jtag-dev +@@ -0,0 +1,23 @@ ++What: /dev/jtag[0-9]+ ++Date: July 2018 ++KernelVersion: 4.20 ++Contact: oleksandrs@mellanox.com ++Description: ++ The misc device files /dev/jtag* are the interface ++ between JTAG master interface and userspace. ++ ++ The ioctl(2)-based ABI is defined and documented in ++ [include/uapi]<linux/jtag.h>. ++ ++ The following file operations are supported: ++ ++ open(2) ++ Opens and allocates file descriptor. ++ ++ ioctl(2) ++ Initiate various actions. ++ See the inline documentation in [include/uapi]<linux/jtag.h> ++ for descriptions of all ioctls. ++ ++Users: ++ userspace tools which wants to access to JTAG bus +diff --git a/Documentation/jtag/overview b/Documentation/jtag/overview +new file mode 100644 +index 000000000000..6a5ec335e313 +--- /dev/null ++++ b/Documentation/jtag/overview +@@ -0,0 +1,27 @@ ++Linux kernel JTAG support ++========================= ++ ++JTAG is an industry standard for verifying hardware. JTAG provides access to ++many logic signals of a complex integrated circuit, including the device pins. ++ ++A JTAG interface is a special interface added to a chip. ++Depending on the version of JTAG, two, four, or five pins are added. ++ ++The connector pins are: ++ TDI (Test Data In) ++ TDO (Test Data Out) ++ TCK (Test Clock) ++ TMS (Test Mode Select) ++ TRST (Test Reset) optional ++ ++JTAG interface is designed to have two parts - basic core driver and ++hardware specific driver. The basic driver introduces a general interface ++which is not dependent of specific hardware. It provides communication ++between user space and hardware specific driver. ++Each JTAG device is represented as a char device from (jtag0, jtag1, ...). ++Access to a JTAG device is performed through IOCTL calls. ++ ++Call flow example: ++User: open -> /dev/jatgX -> JTAG core driver -> JTAG hardware specific driver ++User: ioctl -> /dev/jtagX -> JTAG core driver -> JTAG hardware specific driver ++User: close -> /dev/jatgX -> JTAG core driver -> JTAG hardware specific driver +diff --git a/Documentation/jtag/transactions b/Documentation/jtag/transactions +new file mode 100644 +index 000000000000..f5d4a1ded6cf +--- /dev/null ++++ b/Documentation/jtag/transactions +@@ -0,0 +1,145 @@ ++The JTAG API ++============= ++ ++JTAG master devices can be accessed through a character misc-device. ++Each JTAG master interface can be accessed by using /dev/jtagN. ++ ++JTAG system calls set: ++- SIR (Scan Instruction Register, IEEE 1149.1 Instruction Register scan); ++- SDR (Scan Data Register, IEEE 1149.1 Data Register scan); ++- RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified ++number of clocks. ++ ++open(), close() ++------- ++open() opens JTAG device. ++ ++Open/Close device: ++- jtag_fd = open("/dev/jtag0", O_RDWR); ++- close(jtag_fd); ++ ++ioctl() ++------- ++All access operations to JTAG devices are performed through ioctl interface. ++The IOCTL interface supports these requests: ++ JTAG_SIOCSTATE - Force JTAG state machine to go into a TAPC state ++ JTAG_SIOCFREQ - Set JTAG TCK frequency ++ JTAG_GIOCFREQ - Get JTAG TCK frequency ++ JTAG_IOCXFER - send/receive JTAG data Xfer ++ JTAG_GIOCSTATUS - get current JTAG TAP state ++ JTAG_SIOCMODE - set JTAG mode flags. ++ JTAG_IOCBITBANG - JTAG bitbang low level control. ++ ++JTAG_SIOCFREQ, JTAG_GIOCFREQ ++------ ++Set/Get JTAG clock speed: ++ ++ unsigned int jtag_fd; ++ ioctl(jtag_fd, JTAG_SIOCFREQ, &frq); ++ ioctl(jtag_fd, JTAG_GIOCFREQ, &frq); ++ ++JTAG_SIOCSTATE ++------ ++Force JTAG state machine to go into a TAPC state ++ ++struct jtag_tap_state { ++ __u8 reset; ++ __u8 from; ++ __u8 endstate; ++ __u8 tck; ++}; ++ ++reset: ++ JTAG_NO_RESET - go through selected endstate from current state ++ JTAG_FORCE_RESET - go through TEST_LOGIC/RESET state before selected endstate ++endstate: completion flag ++tck: clock counter ++ ++Example: ++ struct jtag_tap_state tap_state; ++ ++ tap_state.from = JTAG_STATE_TLRESET; ++ tap_state.endstate = JTAG_STATE_IDLE; ++ tap_state.reset = 0; ++ tap_state.tck = data_p->tck; ++ usleep(25 * 1000); ++ ioctl(jtag_fd, JTAG_SIOCSTATE, &tap_state); ++ ++JTAG_GIOCSTATUS ++------ ++Get JTAG TAPC machine state ++ ++ unsigned int jtag_fd; ++ jtag_tapstate tapstate; ++ ioctl(jtag_fd, JTAG_GIOCSTATUS, &tapstate); ++ ++JTAG_IOCXFER ++------ ++Send SDR/SIR transaction ++ ++struct jtag_xfer { ++ __u8 type; ++ __u8 direction; ++ __u8 from; ++ __u8 endstate; ++ __u8 padding; ++ __u32 length; ++ __u64 tdio; ++}; ++ ++type: transfer type - JTAG_SIR_XFER/JTAG_SDR_XFER ++direction: xfer direction - JTAG_READ_XFER/JTAG_WRITE_XFER/JTAG_READ_WRITE_XFER ++length: xfer data length in bits ++tdio : xfer data array ++from: xfer from state can be current JTAG tap state saved by the driver ++ JTAG_STATE_CURRENT or in a multichain environment any state listed in ++ jtag_tapstate struct saved by your multichain controller software. ++endstate: xfer end state after transaction finish ++ can be: any state listed in jtag_tapstate struct ++ ++Example: ++ struct jtag_xfer xfer; ++ static char buf[64]; ++ static unsigned int buf_len = 0; ++ [...] ++ xfer.type = JTAG_SDR_XFER; ++ xfer.tdio = (__u64)buf; ++ xfer.length = buf_len; ++ xfer.from = JTAG_STATE_TLRESET; ++ xfer.endstate = JTAG_STATE_IDLE; ++ ++ if (is_read) ++ xfer.direction = JTAG_READ_XFER; ++ else if (is_write) ++ xfer.direction = JTAG_WRITE_XFER; ++ else ++ xfer.direction = JTAG_READ_WRITE_XFER; ++ ++ ioctl(jtag_fd, JTAG_IOCXFER, &xfer); ++ ++JTAG_SIOCMODE ++------ ++If hardware driver can support different running modes you can change it. ++ ++Example: ++ struct jtag_mode mode; ++ mode.feature = JTAG_XFER_MODE; ++ mode.mode = JTAG_XFER_HW_MODE; ++ ioctl(jtag_fd, JTAG_SIOCMODE, &mode); ++ ++JTAG_IOCBITBANG ++------ ++JTAG Bitbang low level operation. ++ ++Example: ++ struct bitbang_packet bitbang; ++ struct tck_bitbang bitbang_data[2]; ++ bitbang_data[0].tms = 0; ++ bitbang_data[0].tdi = 1; ++ bitbang_data[1].tms = 0; ++ bitbang_data[1].tdi = 1; ++ bitbang.data = bitbang_data; ++ bitbang.length = 2; ++ ioctl(jtag_fd, JTAG_IOCBITBANG, &bitbang); ++ tdo0 = bitbang_data[0].tdo; ++ tdo1 = bitbang_data[1].tdo; +-- +2.7.4 + |