Date: Thu, 6 Aug 2015 20:59:04 +0000 (UTC) From: Ian Lepore <ian@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r286389 - head/share/man/man4 Message-ID: <201508062059.t76Kx4a7027052@repo.freebsd.org>
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Author: ian Date: Thu Aug 6 20:59:03 2015 New Revision: 286389 URL: https://svnweb.freebsd.org/changeset/base/286389 Log: Document the recently added get-bitmode and eeprom read/write functionality. Modified: head/share/man/man4/uftdi.4 Modified: head/share/man/man4/uftdi.4 ============================================================================== --- head/share/man/man4/uftdi.4 Thu Aug 6 20:05:40 2015 (r286388) +++ head/share/man/man4/uftdi.4 Thu Aug 6 20:59:03 2015 (r286389) @@ -29,7 +29,7 @@ .\" .\" $FreeBSD$ .\" -.Dd March 31, 2014 +.Dd August 6, 2015 .Dt UFTDI 4 .Os .Sh NAME @@ -110,6 +110,11 @@ The must be one of the .Va uftdi_bitmodes values. +Setting +.Va mode +to +.Dv UFTDI_BITMODE_NONE +returns the channel to standard UART mode. .Bd -literal enum uftdi_bitmodes { @@ -139,12 +144,15 @@ and data which either reflects pin state or is interpreted as MPSSE commands and parameters, depending on the mode. .It Dv UFTDIIOC_GET_BITMODE Pq Vt "struct uftdi_bitmode" -Return the state of the bitbang pins at the time of the call in the +Return the current bitbang mode in the +.Va mode +member, and the state of the DBUS0..DBUS7 pins at the time +of the call in the .Va iomask member. -The -.Va mode -member is unused. +The pin state can be read while the chip is in any mode, including +.Dv UFTDI_BITMODE_NONE +(UART) mode. .It Dv UFTDIIOC_SET_ERROR_CHAR Pq Vt int Set the character which is inserted into the buffer to mark the point of an error such as FIFO overflow. @@ -164,6 +172,54 @@ This is the .Va bcdDevice value from the .Va usb_device_descriptor . +.It Dv UFTDIIOC_READ_EEPROM Pq Vt "struct uftdi_eeio" +Read one or more words from the configuration eeprom. +The FTDI chip performs eeprom I/O in 16-bit words. +Set +.Va offset +and +.Va length +to values evenly divisible by two before the call, and the +.Va data +array will contain the requested values from eeprom after the call. +.Bd -literal +struct uftdi_eeio +{ + uint16_t offset; + uint16_t length; + uint16_t data[64]; +}; +.Ed +.Pp +The FT232R chip has an internal eeprom. +An external serial eeprom is optional on other FTDI chips. +The eeprom may contain 64, 128, or 256 words, +depending on the part used. +Multiple calls may be needed to read or write the larger parts. +When no eeprom is present, all words in the returned data are 0xffff. +An erased eeprom also reads as all 0xffff. +.It Dv UFTDIIOC_WRITE_EEPROM Pq Vt "struct uftdi_eeio" +Write one or more words to the configuration eeprom. +The +.Va uftdi_eeio +values are as described for +.Dv UFTDIIOC_READ_EEPROM . +.Pp +The FTDI chip does a blind write to the eeprom, and it will appear +to succeed even when no eeprom is present. +To ensure a good write you must read back and verify the data. +It is +.Em not +necessary to erase before writing. +Any position within the eeprom can be overwritten at any time. +.It Dv UFTDIIOC_ERASE_EEPROM Pq Vt int +Erase the entire eeprom. +This is useful primarily for test and debugging, as there is no +need to erase before writing. +To help prevent accidental erasure caused by calling the wrong +ioctl, you must pass the special value +.Dv UFTDI_CONFIRM_ERASE +as the argument to this ioctl. .El .Sh HARDWARE The
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