diff options
Diffstat (limited to 'drivers/spi/spi_butterfly.c')
| -rw-r--r-- | drivers/spi/spi_butterfly.c | 356 |
1 files changed, 0 insertions, 356 deletions
diff --git a/drivers/spi/spi_butterfly.c b/drivers/spi/spi_butterfly.c deleted file mode 100644 index 0d4ceba3b59..00000000000 --- a/drivers/spi/spi_butterfly.c +++ /dev/null @@ -1,356 +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. - */ -#include <linux/kernel.h> -#include <linux/init.h> -#include <linux/delay.h> -#include <linux/device.h> -#include <linux/parport.h> - -#include <linux/sched.h> -#include <linux/spi/spi.h> -#include <linux/spi/spi_bitbang.h> -#include <linux/spi/flash.h> - -#include <linux/mtd/partitions.h> - - -/* - * 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. - */ - - -/* 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_device *dataflash; - 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 - -#include "spi_bitbang_txrx.h" - -static u32 -butterfly_txrx_word_mode0(struct spi_device *spi, - unsigned nsecs, - u32 word, u8 bits) -{ - return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits); -} - -/*----------------------------------------------------------------------*/ - -/* override default partitioning with cmdlinepart */ -static struct mtd_partition partitions[] = { { - /* JFFS2 wants partitions of 4*N blocks for this device, - * so sectors 0 and 1 can't be partitions by themselves. - */ - - /* sector 0 = 8 pages * 264 bytes/page (1 block) - * sector 1 = 248 pages * 264 bytes/page - */ - .name = "bookkeeping", // 66 KB - .offset = 0, - .size = (8 + 248) * 264, -// .mask_flags = MTD_WRITEABLE, -}, { - /* sector 2 = 256 pages * 264 bytes/page - * sectors 3-5 = 512 pages * 264 bytes/page - */ - .name = "filesystem", // 462 KB - .offset = MTDPART_OFS_APPEND, - .size = MTDPART_SIZ_FULL, -} }; - -static struct flash_platform_data flash = { - .name = "butterflash", - .parts = partitions, - .nr_parts = ARRAY_SIZE(partitions), -}; - - -/* 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; - master->num_chipselect = 2; - - 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, "mtd_dataflash"); - pp->info[0].platform_data = &flash; - pp->info[0].chip_select = 1; - pp->info[0].controller_data = pp; - pp->dataflash = spi_new_device(pp->bitbang.master, &pp->info[0]); - if (pp->dataflash) - pr_debug("%s: dataflash at %s\n", p->name, - dev_name(&pp->dataflash->dev)); - - // dev_info(_what?_, ...) - pr_info("%s: AVR Butterfly\n", p->name); - 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; - 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 AVR Butterfly"); -MODULE_LICENSE("GPL"); |