[linux-2.6-block.git] / drivers / spi / 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.
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/module.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 = 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));

	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;

	/* 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 */
	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");
Commit	Line	Data
2e10c84b	1	/*
ca632f55	2	* parport-to-butterfly adapter
2e10c84b DB	3	*
	4	* Copyright (C) 2005 David Brownell
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
2e10c84b	15	*/
2e10c84b DB	16	#include <linux/kernel.h>
	17	#include <linux/init.h>
	18	#include <linux/delay.h>
d7614de4	19	#include <linux/module.h>
da675296	20	#include <linux/device.h>
2e10c84b DB	21	#include <linux/parport.h>
2e10c84b DB	22
914e2637	23	#include <linux/sched.h>
2e10c84b DB	24	#include <linux/spi/spi.h>
	25	#include <linux/spi/spi_bitbang.h>
	26	#include <linux/spi/flash.h>
	27
	28	#include <linux/mtd/partitions.h>
	29
	30
	31	/*
	32	* This uses SPI to talk with an "AVR Butterfly", which is a $US20 card
	33	* with a battery powered AVR microcontroller and lots of goodies. You
	34	* can use GCC to develop firmware for this.
	35	*
	36	* See Documentation/spi/butterfly for information about how to build
	37	* and use this custom parallel port cable.
	38	*/
	39
2e10c84b DB	40
	41	/* DATA output bits (pins 2..9 == D0..D7) */
	42	#define butterfly_nreset (1 << 1) /* pin 3 */
	43
	44	#define spi_sck_bit (1 << 0) /* pin 2 */
	45	#define spi_mosi_bit (1 << 7) /* pin 9 */
	46
2e10c84b DB	47	#define vcc_bits ((1 << 6) \| (1 << 5)) /* pins 7, 8 */
	48
	49	/* STATUS input bits */
	50	#define spi_miso_bit PARPORT_STATUS_BUSY /* pin 11 */
	51
2e10c84b DB	52	/* CONTROL output bits */
2e10c84b DB	53	#define spi_cs_bit PARPORT_CONTROL_SELECT /* pin 17 */
2e10c84b DB	54
	55
	56
	57	static inline struct butterfly spidev_to_pp(struct spi_device spi)
	58	{
	59	return spi->controller_data;
	60	}
	61
2e10c84b DB	62
	63	struct butterfly {
	64	/* REVISIT ... for now, this must be first */
	65	struct spi_bitbang bitbang;
	66
	67	struct parport *port;
	68	struct pardevice *pd;
	69
	70	u8 lastbyte;
	71
	72	struct spi_device *dataflash;
	73	struct spi_device *butterfly;
	74	struct spi_board_info info[2];
	75
	76	};
	77
	78	/----------------------------------------------------------------------/
	79
2e10c84b DB	80	static inline void
	81	setsck(struct spi_device *spi, int is_on)
	82	{
	83	struct butterfly *pp = spidev_to_pp(spi);
	84	u8 bit, byte = pp->lastbyte;
	85
735ce95e	86	bit = spi_sck_bit;
2e10c84b DB	87
	88	if (is_on)
	89	byte \|= bit;
	90	else
	91	byte &= ~bit;
	92	parport_write_data(pp->port, byte);
	93	pp->lastbyte = byte;
	94	}
	95
	96	static inline void
	97	setmosi(struct spi_device *spi, int is_on)
	98	{
	99	struct butterfly *pp = spidev_to_pp(spi);
	100	u8 bit, byte = pp->lastbyte;
	101
735ce95e	102	bit = spi_mosi_bit;
2e10c84b DB	103
	104	if (is_on)
	105	byte \|= bit;
	106	else
	107	byte &= ~bit;
	108	parport_write_data(pp->port, byte);
	109	pp->lastbyte = byte;
	110	}
	111
	112	static inline int getmiso(struct spi_device *spi)
	113	{
	114	struct butterfly *pp = spidev_to_pp(spi);
	115	int value;
	116	u8 bit;
	117
735ce95e	118	bit = spi_miso_bit;
2e10c84b DB	119
	120	/* only STATUS_BUSY is NOT negated */
	121	value = !(parport_read_status(pp->port) & bit);
	122	return (bit == PARPORT_STATUS_BUSY) ? value : !value;
	123	}
	124
	125	static void butterfly_chipselect(struct spi_device *spi, int value)
	126	{
	127	struct butterfly *pp = spidev_to_pp(spi);
	128
	129	/* set default clock polarity */
9c1da3cb	130	if (value != BITBANG_CS_INACTIVE)
2e10c84b DB	131	setsck(spi, spi->mode & SPI_CPOL);
2e10c84b DB	132
9c1da3cb DB	133	/* here, value == "activate or not";
	134	* most PARPORT_CONTROL_* bits are negated, so we must
	135	* morph it to value == "bit value to write in control register"
	136	*/
2e10c84b DB	137	if (spi_cs_bit == PARPORT_CONTROL_INIT)
	138	value = !value;
	139
2e10c84b DB	140	parport_frob_control(pp->port, spi_cs_bit, value ? spi_cs_bit : 0);
	141	}
	142
	143
	144	/* we only needed to implement one mode here, and choose SPI_MODE_0 */
	145
ac8ed236 JH	146	#define spidelay(X) do { } while (0)
ac8ed236 JH	147	/* #define spidelay ndelay */
2e10c84b	148
ca632f55	149	#include "spi-bitbang-txrx.h"
2e10c84b DB	150
	151	static u32
	152	butterfly_txrx_word_mode0(struct spi_device *spi,
	153	unsigned nsecs,
	154	u32 word, u8 bits)
	155	{
04bb2a03	156	return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits);
2e10c84b DB	157	}
	158
	159	/----------------------------------------------------------------------/
	160
	161	/* override default partitioning with cmdlinepart */
	162	static struct mtd_partition partitions[] = { {
9c1da3cb DB	163	/* JFFS2 wants partitions of 4*N blocks for this device,
	164	* so sectors 0 and 1 can't be partitions by themselves.
	165	*/
2e10c84b DB	166
	167	/* sector 0 = 8 pages * 264 bytes/page (1 block)
	168	* sector 1 = 248 pages * 264 bytes/page
	169	*/
ac8ed236	170	.name = "bookkeeping", /* 66 KB */
2e10c84b DB	171	.offset = 0,
2e10c84b DB	172	.size = (8 + 248) * 264,
ac8ed236	173	/* .mask_flags = MTD_WRITEABLE, */
2e10c84b DB	174	}, {
	175	/* sector 2 = 256 pages * 264 bytes/page
	176	* sectors 3-5 = 512 pages * 264 bytes/page
	177	*/
ac8ed236	178	.name = "filesystem", /* 462 KB */
2e10c84b DB	179	.offset = MTDPART_OFS_APPEND,
	180	.size = MTDPART_SIZ_FULL,
	181	} };
	182
	183	static struct flash_platform_data flash = {
	184	.name = "butterflash",
	185	.parts = partitions,
	186	.nr_parts = ARRAY_SIZE(partitions),
	187	};
	188
	189
	190	/* REVISIT remove this ugly global and its "only one" limitation */
	191	static struct butterfly *butterfly;
	192
	193	static void butterfly_attach(struct parport *p)
	194	{
	195	struct pardevice *pd;
	196	int status;
	197	struct butterfly *pp;
	198	struct spi_master *master;
da675296	199	struct device *dev = p->physport->dev;
2e10c84b	200
da675296	201	if (butterfly \|\| !dev)
2e10c84b DB	202	return;
	203
	204	/* REVISIT: this just _assumes_ a butterfly is there ... no probe,
	205	* and no way to be selective about what it binds to.
	206	*/
	207
ac8ed236	208	master = spi_alloc_master(dev, sizeof(*pp));
2e10c84b DB	209	if (!master) {
	210	status = -ENOMEM;
	211	goto done;
	212	}
	213	pp = spi_master_get_devdata(master);
	214
	215	/*
	216	* SPI and bitbang hookup
	217	*
	218	* use default setup(), cleanup(), and transfer() methods; and
	219	* only bother implementing mode 0. Start it later.
	220	*/
	221	master->bus_num = 42;
	222	master->num_chipselect = 2;
	223
94c69f76	224	pp->bitbang.master = master;
2e10c84b DB	225	pp->bitbang.chipselect = butterfly_chipselect;
	226	pp->bitbang.txrx_word[SPI_MODE_0] = butterfly_txrx_word_mode0;
	227
	228	/*
	229	* parport hookup
	230	*/
	231	pp->port = p;
	232	pd = parport_register_device(p, "spi_butterfly",
	233	NULL, NULL, NULL,
	234	0 /* FLAGS */, pp);
	235	if (!pd) {
	236	status = -ENOMEM;
	237	goto clean0;
	238	}
	239	pp->pd = pd;
	240
	241	status = parport_claim(pd);
	242	if (status < 0)
	243	goto clean1;
	244
	245	/*
	246	* Butterfly reset, powerup, run firmware
	247	*/
	248	pr_debug("%s: powerup/reset Butterfly\n", p->name);
	249
	250	/* nCS for dataflash (this bit is inverted on output) */
	251	parport_frob_control(pp->port, spi_cs_bit, 0);
	252
	253	/* stabilize power with chip in reset (nRESET), and
735ce95e	254	* spi_sck_bit clear (CPOL=0)
2e10c84b DB	255	*/
	256	pp->lastbyte \|= vcc_bits;
	257	parport_write_data(pp->port, pp->lastbyte);
	258	msleep(5);
	259
	260	/* take it out of reset; assume long reset delay */
	261	pp->lastbyte \|= butterfly_nreset;
	262	parport_write_data(pp->port, pp->lastbyte);
	263	msleep(100);
	264
	265
	266	/*
	267	* Start SPI ... for now, hide that we're two physical busses.
	268	*/
	269	status = spi_bitbang_start(&pp->bitbang);
	270	if (status < 0)
	271	goto clean2;
	272
9c1da3cb DB	273	/* Bus 1 lets us talk to at45db041b (firmware disables AVR SPI), AVR
	274	* (firmware resets at45, acts as spi slave) or neither (we ignore
	275	* both, AVR uses AT45). Here we expect firmware for the first option.
2e10c84b	276	*/
1fc7547d	277
2e10c84b DB	278	pp->info[0].max_speed_hz = 15 * 1000 * 1000;
	279	strcpy(pp->info[0].modalias, "mtd_dataflash");
	280	pp->info[0].platform_data = &flash;
	281	pp->info[0].chip_select = 1;
	282	pp->info[0].controller_data = pp;
	283	pp->dataflash = spi_new_device(pp->bitbang.master, &pp->info[0]);
	284	if (pp->dataflash)
	285	pr_debug("%s: dataflash at %s\n", p->name,
35f74fca	286	dev_name(&pp->dataflash->dev));
2e10c84b	287
2e10c84b DB	288	pr_info("%s: AVR Butterfly\n", p->name);
	289	butterfly = pp;
	290	return;
	291
	292	clean2:
	293	/* turn off VCC */
	294	parport_write_data(pp->port, 0);
	295
	296	parport_release(pp->pd);
	297	clean1:
	298	parport_unregister_device(pd);
	299	clean0:
	300	(void) spi_master_put(pp->bitbang.master);
	301	done:
2e10c84b DB	302	pr_debug("%s: butterfly probe, fail %d\n", p->name, status);
	303	}
	304
	305	static void butterfly_detach(struct parport *p)
	306	{
	307	struct butterfly *pp;
2e10c84b DB	308
	309	/* FIXME this global is ugly ... but, how to quickly get from
	310	* the parport to the "struct butterfly" associated with it?
	311	* "old school" driver-internal device lists?
	312	*/
	313	if (!butterfly \|\| butterfly->port != p)
	314	return;
	315	pp = butterfly;
	316	butterfly = NULL;
	317
9c1da3cb	318	/* stop() unregisters child devices too */
d9721ae1	319	spi_bitbang_stop(&pp->bitbang);
2e10c84b DB	320
	321	/* turn off VCC */
	322	parport_write_data(pp->port, 0);
	323	msleep(10);
	324
	325	parport_release(pp->pd);
	326	parport_unregister_device(pp->pd);
	327
2e10c84b	328	(void) spi_master_put(pp->bitbang.master);
2e10c84b DB	329	}
	330
	331	static struct parport_driver butterfly_driver = {
	332	.name = "spi_butterfly",
	333	.attach = butterfly_attach,
	334	.detach = butterfly_detach,
	335	};
	336
	337
	338	static int __init butterfly_init(void)
	339	{
	340	return parport_register_driver(&butterfly_driver);
	341	}
	342	device_initcall(butterfly_init);
	343
	344	static void __exit butterfly_exit(void)
	345	{
	346	parport_unregister_driver(&butterfly_driver);
	347	}
	348	module_exit(butterfly_exit);
	349
9c1da3cb	350	MODULE_DESCRIPTION("Parport Adapter driver for AVR Butterfly");
2e10c84b	351	MODULE_LICENSE("GPL");