freecalypso-tools: doc/High-speed-serial annotate

annotate doc/High-speed-serial @ 619:f82551c77e58

libserial-newlnx: ASYNC_LOW_LATENCY patch reverted Reports from Das Signal indicate that loadtools performance on Debian is about the same as on Slackware, and that including or omitting the ASYNC_LOW_LATENCY patch from Serg makes no difference. Because the patch in question does not appear to be necessary, it is being reverted until and unless someone other than Serg reports an actual real-world system on which loadtools operation times are slowed compared to the Mother's Slackware reference and on which Slackware-like performance can be restored by setting the ASYNC_LOW_LATENCY flag.

author	Mychaela Falconia <falcon@freecalypso.org>
date	Thu, 27 Feb 2020 01:09:48 +0000
parents	00805e7c4c45
children	9edb7c07bb29

rev	line source
0 e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	1 The highest baud rate supported by "standard" PC serial ports is 115200 bps,
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	2 but Calypso UARTs can go quite a bit faster. Being clocked with 13 MHz (a
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	3 standard frequency in the GSM world), these UARTs can produce non-standard
258 00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	4 (outside of the GSM world) baud rates of 203125, 406250 and 812500 bps. Even
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	5 though these high baud rates aren't supported by "standard" RS-232 serial ports
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	6 on PCs, they are supported by some of the better USB to serial adapters,
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	7 namely CP2102 (USB to single UART) and the FT2232x family (USB to two UARTs).
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	8 The Pirelli DP-L10 phone supported by FreeCalypso host tools has a CP2102 built
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	9 in, the officially recommended 2.5 mm headset jack USB-serial cables for working
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	10 with Motorola C1xx and Openmoko GTA01/02 phones also use CP2102 adapters,
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	11 whereas our FreeCalypso development boards (FCDEV3B) are typically used with an
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	12 FT2232D or other FT2232x USB to dual UART adapter.
0 e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	13
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	14 FreeCalypso tools can use these high serial baud rates in the following ways:
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	15
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	16 * When you use fc-loadtool to dump and program GSM device flash memory
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	17 (flashing firmware images), the transfers get annoyingly slow at 115200 baud
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	18 if you have to do it a lot. Switching to 406250 or even better 812500 baud
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	19 makes them go considerably faster.
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	20
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	21 * Some of our target devices have large enough RAM to execute a GSM firmware
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	22 image entirely from RAM without flashing - very handy for development and
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	23 experimentation. The tool used to run these RAM-based images is fc-xram,
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	24 and it also supports the option of using high serial baud rates for the image
258 00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	25 transfer for the same reason: repeatedly transferring >2 MiB images over
0 e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	26 115200 baud gets tiresome.
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	27
258 00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	28 * If you are building your own FreeCalypso-based or TI-based GSM firmware in a
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	29 special non-standard configuration, you can make it run its RVTMUX interface
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	30 at 406250 or 812500 baud. We used this trick when we tried to make TCS211
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	31 with D-Sample-targeting UI (176x220 pix LCD, 16 bits per pixel) send its
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	32 virtual LCD raster blits out the serial port. Our rvtdump and rvinterf
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	33 utilities support this mode of operation by providing options to select
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	34 different baud rates.
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	35
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	36 Recent changes for better FTDI adapter support
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	37 ==============================================
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	38
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	39 There is one fundamental difference between the way CP2102 adapters support
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	40 non-standard baud rates (like the high GSM baud rates of interest to us) and
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	41 the way in which FTDI adapters support them. CP2102 chips have a built-in
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	42 EEPROM that contains (among other things) a 32-entry table in which the
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	43 supported serial baud rates are programmed, and the programming of this EEPROM
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	44 effects a remapping: a Linux userspace process can request B230400, B460800 or
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	45 B921600 from termios, but magically get 203125, 406250 or 812500 as the actual
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	46 resulting serial baud rate instead. In contrast, FTDI adapters have no such
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	47 magic remapping mechanism in hardware, thus in order to get 203125, 406250 or
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	48 812500 baud with an FTDI adapter, the userspace process has to explicitly
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	49 request these special baud rates from the serial driver in the kernel, and
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	50 doing the latter requires foregoing the standard termios API and using Linux-
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	51 specific <asm/...> header files and raw ioctl calls instead.
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	52
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	53 When support for high GSM baud rates was first added to FreeCalypso host tools
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	54 back in 2013, there was no need to support the more difficult FTDI adapters as
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	55 the easier to work with CP2102 was fully sufficient for our needs, hence our
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	56 original FC host tools implementation required "magic" baud rate remapping
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	57 somewhere below, usually in form of CP2102 EEPROM programming but also possibly
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	58 by way of a hacky patch to the ftdi_sio driver in the Linux kernel to achieve
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	59 the same effect with rarely-needed FTDI adapters.
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	60
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	61 The situation has changed with the introduction of our own FreeCalypso
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	62 development boards (currently FCDEV3B, possibly others in the future) which
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	63 bring out both Calypso UARTs to the user, rather than just one. The most
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	64 convenient serial adapters for working with these dual UARTs are FT2232x (our
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	65 current official adapter is FT2232D), thus we now have a strong need to support
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	66 the use of these FTDI adapters, including the use of high GSM baud rates, in a
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	67 manner which does not fight against the mainline Linux kernel.
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	68
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	69 In a radical change from fc-host-tools-r6 and earlier, the present version of
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	70 FreeCalypso host tools uses new libserial code that differs from the old code
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	71 as follows:
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	72
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	73 * Linux-specific <asm/...> headers are used instead of <termios.h>;
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	74
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	75 * Linux-specific raw ioctl calls are used instead of tcsetattr() for serial
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	76 port setup;
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	77
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	78 * When the user requests 203125, 406250 or 812500 baud, these are the actual
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	79 baud rates requested from the kernel, not 230400/460800/921600 baud.
0 e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	80
258 00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	81 This change is expected to have no adverse effect on the existing CP2102 users,
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	82 as the cp210x driver in Linux appears to cope fine with the strange baud rate
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	83 requests from userspace and the correct CP2102 EEPROM baud rate entry still
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	84 gets selected (tested on Slackware 13.37 and Debian 9), but when working with
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	85 FTDI adapters such as our FT2232D adapter for the FCDEV3B this change makes the
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	86 high GSM baud rates work without needing the dirty kernel patch which the
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	87 Mother has been using up until now.
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	88
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	89 Support for other Unix flavors
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	90 ==============================
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	91
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	92 The serial port handling code for all of FC host tools has been factored out
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	93 into a common library called libserial. We have two versions of libserial:
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	94
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	95 * libserial-orig uses the standard and presumably portable termios API, but
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	96 requires "magic" remapping of baud rates by some invisible genie below (like
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	97 CP2102 EEPROM programming) in order to get 203125/406250/812500 baud.
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	98
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	99 * libserial-newlnx uses Linux-specific header files and raw ioctl calls to
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	100 request the actual desired baud rates.
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	101
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	102 If you would like to run FreeCalypso host tools under FreeBSD, illumos or some
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	103 other alternative-to-Linux OS, you have two basic choices:
0 e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	104
258 00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	105 * If you wish to use high GSM baud rates with non-remapping FTDI adapters or
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	106 other serial interfaces which support the baud rates in question without
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	107 remapping, you will need to figure out how to request non-standard serial
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	108 baud rates from the underlying drivers under your OS, and create your own
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	109 version of libserial ported to use that method.
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	110
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	111 * If you don't need high GSM baud rates or need them only with CP2102 adapters
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	112 which "magically" remap them, you should be able to use libserial-orig. You
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	113 can also completely remove the entries for the high GSM baud rates from
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	114 libserial-orig/baudtab.c if you don't need these high baud rates and your
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	115 version of termios does not have B230400/B460800/B921600 baud rate constants.
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	116
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	117 It is assumed that any system on which someone may desire to run our FC host
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	118 tools supports at least 115200 baud. The Mother remembers the days when this
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	119 baud rate was considered very high and non-standard and even has some of those
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	120 lovely old systems still running; fc-loadtool and friends going through the
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	121 Calypso boot ROM (not through Compal's bootloader) can be made to work with a
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	122 host system whose UARTs max out at 19200 baud, but most Calypso GSM device
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	123 firmwares including our own use the 115200 baud rate.
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	124
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	125 Using CP2102 adapters with Mot C1xx and Openmoko phones
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	126 =======================================================
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	127
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	128 As already mentioned above, CP2102 chips have a built-in EEPROM that contains
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	129 (among other things) a 32-entry table in which the supported serial baud rates
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	130 are programmed. In order to support the special GSM baud rates, these rates
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	131 need to be added to that table, displacing some other entries. The convention
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	132 established by the Pirelli DP-L10 phone (has a CP2102 built in and programmed
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	133 at the factory for GSM baud rates) is that 203120 baud takes the place of
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	134 230400, 406250 takes the place of 460800, and 812500 takes the place of 921600.
0 e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	135
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	136 Because you need a special cable anyway to make the necessary physical
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	137 connection to the debug/programming serial port presented on a 2.5 mm headset
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	138 jack, you will probably be buying the requisite cable from a specialized
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	139 professional vendor. In that case it is that vendor's responsibility to sell
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	140 you the cable with the CP2102 chip already programmed with GSM baud rates:
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	141 because the physical construction of the cable (2.5 mm headset jack on the
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	142 serial end) makes it specific to GSM devices, and all known GSM devices use a
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	143 13 MHz clock or some integer multiple thereof, it is pointless for a
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	144 physically-GSM-specific cable to be set up for 230400/460800/921600 baud when
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	145 all known GSM devices will need 203125/406250/812500 baud instead.
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	146
258 00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	147 If you are making a CP2102-based serial cable yourself (either for your own
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	148 personal use or professionally/commercially), please follow these instructions
00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	149 for baud rate programming:
0 e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	150
258 00805e7c4c45 doc/High-speed-serial: update/rewrite for the new FTDI support Mychaela Falconia <falcon@freecalypso.org> parents: 0 diff changeset	151 http://osmocom.org/projects/baseband/wiki/HardwareCP210xTutorial
0 e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	152
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	153 If you follow the procedure given on that page, your CP2102 will be programmed
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	154 the same way as the one in the Pirelli DP-L10 (Foxconn's original factory
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	155 programming).
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	156
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	157 Using adapters built into phones
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	158 ================================
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	159
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	160 The Calypso chip has no native USB capabilities, thus if a Calypso phone
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	161 presents a USB charging+data port to the user, it must have a USB to serial
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	162 converter built in. The only phone we currently know of that does this is
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	163 Pirelli DP-L10, and its built-in USB-serial adapter chip is CP2102. It has
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	164 already been programmed with the correct GSM baud rates on Foxconn's original
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	165 production line, thus one can always use 812500 baud with FreeCalypso tools on
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7 Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	166 this phone and it will Just Work.

FreeCalypso > hg > freecalypso-tools

annotate doc/High-speed-serial @ 619:f82551c77e58