X-Git-Url: http://git.linex4red.de/pub/spi-gpio-pp.git/blobdiff_plain/ed56ae3ac69596bea18437ef0b0752d64b7e6d49..b64fc7ae9036d15175c5dacaf8df3b9109eaf2f5:/spi_tty.c diff --git a/spi_tty.c b/spi_tty.c deleted file mode 100644 index 02e26e1..0000000 --- a/spi_tty.c +++ /dev/null @@ -1,453 +0,0 @@ -/* - * spi_butterfly.c - parport-to-butterfly adapter - * - * Copyright (C) 2005 David Brownell - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - * - * idea: - * separate the butterfly driver into a hotpluggable SPI master controller - * use a board description file, which loads the: - * - the SPI master controller - * - the SPI protocoll driver - * call spi_new_device with - - spi_master = butterfly parport driver (or parameter configurable) - - spi_board_info = infos about Mauro-Lite - - */ -#include -#include -#include -#include -#include - -#include -#include -#include - - - -/* - * This uses SPI to talk with an "AVR Butterfly", which is a $US20 card - * with a battery powered AVR microcontroller and lots of goodies. You - * can use GCC to develop firmware for this. - * - * See Documentation/spi/butterfly for information about how to build - * and use this custom parallel port cable. - */ - -/* - * spi_device - * todo: - * - implement SPI mode 1,2,3 is yet missing - * - prevent ugly handling of global butterfly structure - * - use serial subsystem - * - make stuff module configurable during runtime - */ - -/* DATA output bits (pins 2..9 == D0..D7) */ -#define MODALIASLEN 10 -#define DRVNAME "spi_butterfly" -#define DRIVER_VERSION "0.2" - -#define butterfly_nreset (1 << 1) /* pin 3 */ - -#define spi_sck_bit (1 << 0) /* pin 2 */ -#define spi_mosi_bit (1 << 7) /* pin 9 */ - -#define vcc_bits ((1 << 6) | (1 << 5)) /* pins 7, 8 */ - -/* STATUS input bits */ -#define spi_miso_bit PARPORT_STATUS_BUSY /* pin 11 */ - -/* CONTROL output bits */ -#define spi_cs_bit PARPORT_CONTROL_SELECT /* pin 17 */ - -/* - * Parallel - * Port Direction Signal - * ----------- --------- ------------ - * D0 2 --> SCLK - * D1 3 --> nRESET - * D2 4 --> -- - * D3 5 --> -- - * D4 6 --> -- - * D5 7 --> -- - * D6 8 --> -- - * D7 9 --> MOSI - * GND 25 - GND - * Busy 11 <-- MISO - * Paper 12 <-- -- - * Select 13 <-- -- - * Feed 14 --> -- - * Error 15 <-- -- - * Init 16 --> -- - * Select 17 --> nCS - */ - -//***************************************************************************** -// Globals -//***************************************************************************** -/* module parameters */ -static char modalias[MODALIASLEN] = "maurol"; - -static inline struct butterfly *spidev_to_pp(struct spi_device *spi) -{ - return spi->controller_data; -} - - -struct butterfly { - /* REVISIT ... for now, this must be first */ - struct spi_bitbang bitbang; - - struct parport *port; - struct pardevice *pd; - - u8 lastbyte; /* hold copy of partport to be faster */ - - struct spi_message *msg; - struct spi_device *butterfly; - struct spi_board_info info; - -}; - -/*----------------------------------------------------------------------*/ - - -static inline void -setsck(struct spi_device *spi, int is_on) -{ - struct butterfly *pp = spidev_to_pp(spi); - u8 bit, byte = pp->lastbyte; - - bit = spi_sck_bit; - - if (is_on) - byte |= bit; - else - byte &= ~bit; - parport_write_data(pp->port, byte); - pp->lastbyte = byte; /* use parport mirror to be faster */ -} - -static inline void -setmosi(struct spi_device *spi, int is_on) -{ - struct butterfly *pp = spidev_to_pp(spi); - u8 bit, byte = pp->lastbyte; - - bit = spi_mosi_bit; - - if (is_on) - byte |= bit; - else - byte &= ~bit; - parport_write_data(pp->port, byte); - pp->lastbyte = byte; /* use parport mirror to be faster */ -} - -static inline int getmiso(struct spi_device *spi) -{ - struct butterfly *pp = spidev_to_pp(spi); - int value; - u8 bit; - - bit = spi_miso_bit; - - /* only STATUS_BUSY is NOT negated */ - value = !(parport_read_status(pp->port) & bit); - return (bit == PARPORT_STATUS_BUSY) ? value : !value; -} - -static void butterfly_chipselect(struct spi_device *spi, int value) -{ - struct butterfly *pp = spidev_to_pp(spi); - -#if 0 - /* set default clock polarity */ - if (value != BITBANG_CS_INACTIVE) - setsck(spi, spi->mode & SPI_CPOL); - - /* here, value == "activate or not"; - * most PARPORT_CONTROL_* bits are negated, so we must - * morph it to value == "bit value to write in control register" - */ - if (spi_cs_bit == PARPORT_CONTROL_INIT) - value = !value; - - parport_frob_control(pp->port, spi_cs_bit, value ? spi_cs_bit : 0); -#else - u8 bit, byte = pp->lastbyte; - - bit = butterfly_nreset; - - if (value) - byte &= ~bit; - else - byte |= bit; - parport_write_data(pp->port, byte); - pp->lastbyte = byte; /* use parport mirror to be faster */ -#endif -} - - -/* we only needed to implement one mode here, and choose SPI_MODE_0 */ - -#define spidelay(X) do{}while(0) -//#define spidelay ndelay - -#define EXPAND_BITBANG_TXRX -#include - -static u32 -butterfly_txrx_word_mode0(struct spi_device *spi, - unsigned nsecs, - u32 word, u8 bits) -{ - return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits); -} - -/*----------------------------------------------------------------------*/ - -/* REVISIT remove this ugly global and its "only one" limitation */ -static struct butterfly *butterfly; - -static void butterfly_attach(struct parport *p) -{ - struct pardevice *pd; - int status; - struct butterfly *pp; - struct spi_master *master; - struct device *dev = p->physport->dev; - - if (butterfly || !dev) - return; - - /* REVISIT: this just _assumes_ a butterfly is there ... no probe, - * and no way to be selective about what it binds to. - */ - - master = spi_alloc_master(dev, sizeof *pp); - if (!master) { - status = -ENOMEM; - goto done; - } - pp = spi_master_get_devdata(master); - - master->bus_num = -1; /* dynamic alloc of a bus number */ - master->num_chipselect = 1; - - /* - * SPI and bitbang hookup - * - * use default setup(), cleanup(), and transfer() methods; and - * only bother implementing mode 0. Start it later. - */ - pp->bitbang.master = spi_master_get(master); - pp->bitbang.chipselect = butterfly_chipselect; - pp->bitbang.txrx_word[SPI_MODE_0] = butterfly_txrx_word_mode0; - pp->bitbang.flags = SPI_3WIRE; // #################################### - - /* - * parport hookup - */ - pp->port = p; - pd = parport_register_device(p, DRVNAME, - NULL, NULL, NULL, - 0 /* FLAGS */, pp); //PARPORT_FLAG_EXCL, pp); - if (!pd) { - status = -ENOMEM; - goto clean0; - } - pp->pd = pd; - - status = parport_claim(pd); - if (status < 0) - goto clean1; - - pp->lastbyte = 0; - parport_write_data(pp->port, pp->lastbyte); - - /* - * Butterfly reset, powerup, run firmware - */ - pr_debug("%s: powerup/reset Butterfly\n", DRVNAME); - - /* nCS for dataflash (this bit is inverted on output) */ - parport_frob_control(pp->port, spi_cs_bit, 0); - - /* stabilize power with chip in reset (nRESET), and - * spi_sck_bit clear (CPOL=0) - */ - pp->lastbyte |= vcc_bits; - parport_write_data(pp->port, pp->lastbyte); - msleep(5); - -#if 0 - /* take it out of reset; assume long reset delay */ - pp->lastbyte |= butterfly_nreset; - parport_write_data(pp->port, pp->lastbyte); - msleep(10); - - /* take reset as trigger signal ############# */ - pp->lastbyte &= ~butterfly_nreset; - parport_write_data(pp->port, pp->lastbyte); -#endif - - /* - * Start SPI ... for now, hide that we're two physical busses. - */ - status = spi_bitbang_start(&pp->bitbang); - if (status < 0) { - pr_warning("%s: spi_bitbang_start failed with status %d\n", - DRVNAME, status); - goto clean2; - } - - /* - * The modalias name MUST match the device_driver name - * for the bus glue code to match and subsequently bind them. - * We are binding to the generic drivers/hwmon/lm70.c device - * driver. - */ - if (modalias[0]) { - pr_info("%s: Will load protocol driver: '%s'!\n", DRVNAME, modalias); - } else goto clean2; - - /* need to make this parameter loadable */ - strcpy(pp->info.modalias, modalias); - pp->info.max_speed_hz = 15 * 1000 * 1000; - pp->info.chip_select = 0; // 0: .. 1: - pp->info.mode = SPI_3WIRE | SPI_MODE_0; // ################ - - /* Enable access to our primary data structure via - * the board info's (void *)controller_data. - */ - pp->info.platform_data = NULL; // here we should add data structures for subsystem driver ??? - pp->info.controller_data = pp; /* save my structure for later use */ - pp->butterfly = spi_new_device(pp->bitbang.master, &pp->info); - if (pp->butterfly) - pr_info("%s: SPI tty at %s\n", DRVNAME, - pp->butterfly->dev.bus_id); - else { - pr_warning("%s: spi_new_device failed\n", DRVNAME); - status = -ENODEV; - goto out_bitbang_stop; - } - // pp->butterfly->bits_per_word=16; // ############### - - /* get spi_bitbang_transfer either via global Symbol, or better - * ask it from the driver structure - */ - pp->msg = spi_message_alloc(1, GFP_KERNEL); - if (master) { /* the same address is also saved in pp->bitbang.master or pp->butterfly->master */ - struct spi_message *spi_msg; - spi_msg = pp->msg; - if (spi_msg) { - // spi_message_init(spi_msg); - pr_info("Alloc SPI message buffer\n"); - spi_msg->spi = pp->butterfly; - spi_msg->actual_length = 1; -#if 0 - spi_msg->list_head ... Addresse der ersten SPI transfer struct - - - spi_msg->tx_buf = ; - spi_msg->len = 1; - spi_msg->cs_change = 1; - spi_msg->delay_usecs = 0; - - /* fill up message */ - master->transfer(pp->butterfly, spi_msg); -#endif - } - } - butterfly = pp; - return; - -out_bitbang_stop: - spi_bitbang_stop(&pp->bitbang); -clean2: - /* turn off VCC */ - parport_write_data(pp->port, 0); - - parport_release(pp->pd); -clean1: - parport_unregister_device(pd); -clean0: - (void) spi_master_put(pp->bitbang.master); -done: - pr_debug("%s: butterfly probe, fail %d\n", DRVNAME, status); -} - -static void butterfly_detach(struct parport *p) -{ - struct butterfly *pp; - int status; - - /* FIXME this global is ugly ... but, how to quickly get from - * the parport to the "struct butterfly" associated with it? - * "old school" driver-internal device lists? - */ - if (!butterfly || butterfly->port != p) - return; - pp = butterfly; - if (pp->msg) { - spi_message_free(pp->msg); - pr_info("Dealloc SPI message buffer\n"); - } - - /* stop() unregisters child devices too */ - status = spi_bitbang_stop(&pp->bitbang); - - /* turn off VCC */ - parport_write_data(pp->port, 0); - msleep(10); - - parport_release(pp->pd); - parport_unregister_device(pp->pd); - - (void) spi_master_put(pp->bitbang.master); - - butterfly = NULL; -} - -static struct parport_driver butterfly_driver = { - .name = DRVNAME, - .attach = butterfly_attach, - .detach = butterfly_detach, -}; - - -static int __init butterfly_init(void) -{ - return parport_register_driver(&butterfly_driver); -} -device_initcall(butterfly_init); - -static void __exit butterfly_exit(void) -{ - parport_unregister_driver(&butterfly_driver); -} -module_exit(butterfly_exit); - -MODULE_DESCRIPTION("Parport Adapter driver for SPI tty Butterfly"); -MODULE_LICENSE("GPL"); - -module_param_string(spi_pdrv, modalias, sizeof(modalias), S_IRUGO); -MODULE_PARM_DESC(spi_pdrv, "spi protocol driver name"); - -MODULE_INFO(Version, DRIVER_VERSION);