From: Peter Henn Date: Wed, 31 Dec 2008 15:55:17 +0000 (+0100) Subject: SPI Parport controller forked from spi_butterfly X-Git-Tag: v0.2~6 X-Git-Url: http://git.linex4red.de/pub/spi-gpio-pp.git/commitdiff_plain/89a4251cdbaaf15edbb1b4ff4e7de265ef8ca364?ds=inline SPI Parport controller forked from spi_butterfly It is just the first try to get a feeling, how the SPI Parport controller can work on the parport. --- 89a4251cdbaaf15edbb1b4ff4e7de265ef8ca364 diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..9f13a83 --- /dev/null +++ b/Makefile @@ -0,0 +1,130 @@ +# +# Makefile for the Linux WWAN device drivers. +# +# NOTE: This make file can serve as both an external Makefile (launched +# directly by the user), or as the sub-dir Makefile used by the kernel +# build system. + +# If CONFIG_SPI_TTY isn't set, we'll assume the user has never configured +# their kernel to include this module and set up some defaults. +# +# NOTE: If you have previously added the SPI_TTY project to your kernel +# and configured it for inclusion, these settings will be +# overridden by your kernel configuration. +ifndef CONFIG_SPI_TTY +EXTERNAL_BUILD=y +CONFIG_SPI_TTY=m +CONFIG_SPI_TTY_DEBUG=n +endif + + +ifeq ($(CONFIG_SPI_TTY_DEBUG),y) + EXTRA_CFLAGS += -g -Wa,-adhlms=$@.lst +endif + +ifdef KBUILD_EXTMOD + EXTRA_CFLAGS += -I$(KBUILD_EXTMOD) +endif + + +list-m := +list-$(CONFIG_SPI_TTY) += spi_tty +obj-$(CONFIG_SPI_TTY) += spi_tty.o + +# +# Begin dual Makefile mode here. First we provide support for when we +# are being invoked by the kernel build system +# +ifneq ($(KERNELRELEASE),) + +EXTRA_CFLAGS += -DCONFIG_PM + +ifeq ($(EXTERNAL_BUILD),y) +ifeq ($(CONFIG_SPI_TTY_DEBUG),y) +EXTRA_CFLAGS += -DCONFIG_SPI_TTY_DEBUG +endif +endif + +else +# Here we begin the portion that is executed if the user invoked this Makefile +# directly. + +# KSRC should be set to the path to your sources +KVER := $(shell uname -r) +KSRC := /lib/modules/$(KVER)/build +INSTALLDIR:=/lib/modules/$(KVER)/kernel/drivers/net/wwan/ + +# KSRC_OUTPUT should be overridden if you are using a 2.6 kernel that +# has it's output sent elsewhere via KBUILD_OUTPUT= or O= +KSRC_OUTPUT := $(KSRC) + +PWD=$(shell pwd) + +VERFILE := $(KSRC_OUTPUT)/include/linux/version.h +KERNELRELEASE := $(shell \ + if [ -r $(VERFILE) ]; then \ + (cat $(VERFILE); echo UTS_RELEASE) | \ + $(CC) -I$(KSRC_OUTPUT) $(CFLAGS) -E - | \ + tail -n 1 | \ + xargs echo; \ + else \ + uname -r; \ + fi) + +MODPATH := $(DESTDIR)/lib/modules/$(KERNELRELEASE) + +all: modules + +clean: + $(RM) -f *.mod.* *.mod *.o *.ko .*.o.cmd .*.ko.cmd *.flags .lst *.lst Module*.symvers + $(RM) -rf $(PWD)/tmp + $(RM) -rf .tmp_versions + +distclean: clean + rm -f tags TAGS + +TMP=$(PWD)/tmp +MODVERDIR=$(TMP)/.tmp_versions + +modules: + mkdir -p $(MODVERDIR) +ifdef ($(KSRC_OUTPUT)/.tmp_versions) + -cp $(KSRC_OUTPUT)/.tmp_versions/*.mod $(MODVERDIR) +endif +ifeq ($(KSRC),$(KSRC_OUTPUT)) # We're not outputting elsewhere +ifdef ($(KSRC)/.tmp_versions) + -cp $(KSRC)/.tmp_versions/*.mod $(MODVERDIR) +endif + $(MAKE) -C $(KSRC) M=$(PWD) MODVERDIR=$(MODVERDIR) modules +else # We've got a kernel with seperate output, copy the config, and use O= + mkdir -p $(TMP) + cp $(KSRC_OUTPUT)/.config $(TMP) + $(MAKE) -C $(KSRC) M=$(PWD) MODVERDIR=$(MODVERDIR)) O=$(PWD)/tmp modules +endif + +install: modules + modprobe -r spi_tty || true + install -d $(INSTALLDIR) + install -m 644 -c $(addsuffix .ko,$(list-m)) $(INSTALLDIR) + /sbin/depmod -a ${KVER} + +uninstall: + rm -rf $(addprefix $(INSTALLDIR),$(addsuffix .ko,$(list-m))) + /sbin/depmod -a ${KVER} + +endif # End of internal build + +.PHONY: TAGS tags + +RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o -name CVS \) -prune -o +define all-sources + ( find . $(RCS_FIND_IGNORE) -name '*.[chS]' -print ) +endef + +TAGS: + $(all-sources) | etags - +tags: + $(RM) -f $@ + CTAGSF=`ctags --version | grep -i exuberant >/dev/null && echo "-I __initdata,__exitdata,EXPORT_SYMBOL,EXPORT_SYMBOL_NOVERS"`; \ + $(all-sources) | xargs ctags $$CTAGSF -a + diff --git a/spi_tty.c b/spi_tty.c new file mode 100644 index 0000000..1a80bea --- /dev/null +++ b/spi_tty.c @@ -0,0 +1,367 @@ +/* + * 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. + */ +#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 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 */ + + + +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; + + struct spi_message *msg; + struct spi_device *butterfly; + struct spi_board_info info[2]; + +}; + +/*----------------------------------------------------------------------*/ + +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; +} + +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; +} + +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); + + /* 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); +} + + +/* 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); + + /* + * SPI and bitbang hookup + * + * use default setup(), cleanup(), and transfer() methods; and + * only bother implementing mode 0. Start it later. + */ + master->bus_num = 42; // hard coded?!? + master->num_chipselect = 2; // hard coded?!? + + pp->bitbang.master = spi_master_get(master); + pp->bitbang.chipselect = butterfly_chipselect; + pp->bitbang.txrx_word[SPI_MODE_0] = butterfly_txrx_word_mode0; + + /* + * parport hookup + */ + pp->port = p; + pd = parport_register_device(p, "spi_butterfly", + NULL, NULL, NULL, + 0 /* FLAGS */, pp); + if (!pd) { + status = -ENOMEM; + goto clean0; + } + pp->pd = pd; + + status = parport_claim(pd); + if (status < 0) + goto clean1; + + /* + * Butterfly reset, powerup, run firmware + */ + pr_debug("%s: powerup/reset Butterfly\n", p->name); + + /* 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); + + /* take it out of reset; assume long reset delay */ + pp->lastbyte |= butterfly_nreset; + parport_write_data(pp->port, pp->lastbyte); + msleep(100); + + + /* + * Start SPI ... for now, hide that we're two physical busses. + */ + status = spi_bitbang_start(&pp->bitbang); + if (status < 0) + goto clean2; + + /* Bus 1 lets us talk to at45db041b (firmware disables AVR SPI), AVR + * (firmware resets at45, acts as spi slave) or neither (we ignore + * both, AVR uses AT45). Here we expect firmware for the first option. + */ + + pp->info[0].max_speed_hz = 15 * 1000 * 1000; + + strcpy(pp->info[0].modalias, "spi_tty"); // name length check ! < KOBJ_NAME_LEN + pp->info[0].platform_data = NULL; // here we should add data structures for subsystem driver ??? + pp->info[0].chip_select = 1; // 0: .. 1: + pp->info[0].controller_data = pp; /* save my structure for later use */ + pp->butterfly = spi_new_device(pp->bitbang.master, &pp->info[0]); + if (pp->butterfly) + pr_debug("%s: dataflash at %s\n", p->name, + pp->butterfly->dev.bus_id); + + // dev_info(_what?_, ...) + pr_info("%s: AVR Butterfly\n", p->name); + + + /* 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; + +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", p->name, 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"); + } + butterfly = NULL; + + /* 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); +} + +static struct parport_driver butterfly_driver = { + .name = "spi_butterfly", + .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");