[linux.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, unsigned flags)
{
	return bitbang_txrx_be_cpha0(spi, nsecs, 0, flags, 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;
	struct pardev_cb	butterfly_cb;

	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;
	memset(&butterfly_cb, 0, sizeof(butterfly_cb));
	butterfly_cb.private = pp;
	pd = parport_register_dev_model(p, "spi_butterfly", &butterfly_cb, 0);
	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:
	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);

	spi_master_put(pp->bitbang.master);
}

static struct parport_driver butterfly_driver = {
	.name =		"spi_butterfly",
	.match_port =	butterfly_attach,
	.detach =	butterfly_detach,
	.devmodel = true,
};

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
2e10c84b DB	30	/*
	31	* This uses SPI to talk with an "AVR Butterfly", which is a $US20 card
	32	* with a battery powered AVR microcontroller and lots of goodies. You
	33	* can use GCC to develop firmware for this.
	34	*
	35	* See Documentation/spi/butterfly for information about how to build
	36	* and use this custom parallel port cable.
	37	*/
	38
2e10c84b DB	39	/* DATA output bits (pins 2..9 == D0..D7) */
	40	#define butterfly_nreset (1 << 1) /* pin 3 */
	41
	42	#define spi_sck_bit (1 << 0) /* pin 2 */
	43	#define spi_mosi_bit (1 << 7) /* pin 9 */
	44
2e10c84b DB	45	#define vcc_bits ((1 << 6) \| (1 << 5)) /* pins 7, 8 */
	46
	47	/* STATUS input bits */
	48	#define spi_miso_bit PARPORT_STATUS_BUSY /* pin 11 */
	49
2e10c84b DB	50	/* CONTROL output bits */
2e10c84b DB	51	#define spi_cs_bit PARPORT_CONTROL_SELECT /* pin 17 */
2e10c84b	52
2e10c84b DB	53	static inline struct butterfly spidev_to_pp(struct spi_device spi)
	54	{
	55	return spi->controller_data;
	56	}
	57
2e10c84b DB	58	struct butterfly {
	59	/* REVISIT ... for now, this must be first */
	60	struct spi_bitbang bitbang;
	61
	62	struct parport *port;
	63	struct pardevice *pd;
	64
	65	u8 lastbyte;
	66
	67	struct spi_device *dataflash;
	68	struct spi_device *butterfly;
	69	struct spi_board_info info[2];
	70
	71	};
	72
	73	/----------------------------------------------------------------------/
	74
2e10c84b DB	75	static inline void
	76	setsck(struct spi_device *spi, int is_on)
	77	{
	78	struct butterfly *pp = spidev_to_pp(spi);
	79	u8 bit, byte = pp->lastbyte;
	80
735ce95e	81	bit = spi_sck_bit;
2e10c84b DB	82
	83	if (is_on)
	84	byte \|= bit;
	85	else
	86	byte &= ~bit;
	87	parport_write_data(pp->port, byte);
	88	pp->lastbyte = byte;
	89	}
	90
	91	static inline void
	92	setmosi(struct spi_device *spi, int is_on)
	93	{
	94	struct butterfly *pp = spidev_to_pp(spi);
	95	u8 bit, byte = pp->lastbyte;
	96
735ce95e	97	bit = spi_mosi_bit;
2e10c84b DB	98
	99	if (is_on)
	100	byte \|= bit;
	101	else
	102	byte &= ~bit;
	103	parport_write_data(pp->port, byte);
	104	pp->lastbyte = byte;
	105	}
	106
	107	static inline int getmiso(struct spi_device *spi)
	108	{
	109	struct butterfly *pp = spidev_to_pp(spi);
	110	int value;
	111	u8 bit;
	112
735ce95e	113	bit = spi_miso_bit;
2e10c84b DB	114
	115	/* only STATUS_BUSY is NOT negated */
	116	value = !(parport_read_status(pp->port) & bit);
	117	return (bit == PARPORT_STATUS_BUSY) ? value : !value;
	118	}
	119
	120	static void butterfly_chipselect(struct spi_device *spi, int value)
	121	{
	122	struct butterfly *pp = spidev_to_pp(spi);
	123
	124	/* set default clock polarity */
9c1da3cb	125	if (value != BITBANG_CS_INACTIVE)
2e10c84b DB	126	setsck(spi, spi->mode & SPI_CPOL);
2e10c84b DB	127
9c1da3cb DB	128	/* here, value == "activate or not";
	129	* most PARPORT_CONTROL_* bits are negated, so we must
	130	* morph it to value == "bit value to write in control register"
	131	*/
2e10c84b DB	132	if (spi_cs_bit == PARPORT_CONTROL_INIT)
	133	value = !value;
	134
2e10c84b DB	135	parport_frob_control(pp->port, spi_cs_bit, value ? spi_cs_bit : 0);
	136	}
	137
2e10c84b DB	138	/* we only needed to implement one mode here, and choose SPI_MODE_0 */
2e10c84b DB	139
ac8ed236 JH	140	#define spidelay(X) do { } while (0)
ac8ed236 JH	141	/* #define spidelay ndelay */
2e10c84b	142
ca632f55	143	#include "spi-bitbang-txrx.h"
2e10c84b DB	144
2e10c84b DB	145	static u32
e71fec73	146	butterfly_txrx_word_mode0(struct spi_device *spi, unsigned nsecs, u32 word,
304d3436	147	u8 bits, unsigned flags)
2e10c84b	148	{
304d3436	149	return bitbang_txrx_be_cpha0(spi, nsecs, 0, flags, word, bits);
2e10c84b DB	150	}
	151
	152	/----------------------------------------------------------------------/
	153
	154	/* override default partitioning with cmdlinepart */
	155	static struct mtd_partition partitions[] = { {
9c1da3cb DB	156	/* JFFS2 wants partitions of 4*N blocks for this device,
	157	* so sectors 0 and 1 can't be partitions by themselves.
	158	*/
2e10c84b DB	159
	160	/* sector 0 = 8 pages * 264 bytes/page (1 block)
	161	* sector 1 = 248 pages * 264 bytes/page
	162	*/
ac8ed236	163	.name = "bookkeeping", /* 66 KB */
2e10c84b DB	164	.offset = 0,
2e10c84b DB	165	.size = (8 + 248) * 264,
ac8ed236	166	/* .mask_flags = MTD_WRITEABLE, */
2e10c84b DB	167	}, {
	168	/* sector 2 = 256 pages * 264 bytes/page
	169	* sectors 3-5 = 512 pages * 264 bytes/page
	170	*/
ac8ed236	171	.name = "filesystem", /* 462 KB */
2e10c84b DB	172	.offset = MTDPART_OFS_APPEND,
	173	.size = MTDPART_SIZ_FULL,
	174	} };
	175
	176	static struct flash_platform_data flash = {
	177	.name = "butterflash",
	178	.parts = partitions,
	179	.nr_parts = ARRAY_SIZE(partitions),
	180	};
	181
2e10c84b DB	182	/* REVISIT remove this ugly global and its "only one" limitation */
	183	static struct butterfly *butterfly;
	184
	185	static void butterfly_attach(struct parport *p)
	186	{
	187	struct pardevice *pd;
	188	int status;
	189	struct butterfly *pp;
	190	struct spi_master *master;
da675296	191	struct device *dev = p->physport->dev;
1d3029cc	192	struct pardev_cb butterfly_cb;
2e10c84b	193
da675296	194	if (butterfly \|\| !dev)
2e10c84b DB	195	return;
	196
	197	/* REVISIT: this just _assumes_ a butterfly is there ... no probe,
	198	* and no way to be selective about what it binds to.
	199	*/
	200
ac8ed236	201	master = spi_alloc_master(dev, sizeof(*pp));
2e10c84b DB	202	if (!master) {
	203	status = -ENOMEM;
	204	goto done;
	205	}
	206	pp = spi_master_get_devdata(master);
	207
	208	/*
	209	* SPI and bitbang hookup
	210	*
	211	* use default setup(), cleanup(), and transfer() methods; and
	212	* only bother implementing mode 0. Start it later.
	213	*/
	214	master->bus_num = 42;
	215	master->num_chipselect = 2;
	216
94c69f76	217	pp->bitbang.master = master;
2e10c84b DB	218	pp->bitbang.chipselect = butterfly_chipselect;
	219	pp->bitbang.txrx_word[SPI_MODE_0] = butterfly_txrx_word_mode0;
	220
	221	/*
	222	* parport hookup
	223	*/
	224	pp->port = p;
1d3029cc SM	225	memset(&butterfly_cb, 0, sizeof(butterfly_cb));
	226	butterfly_cb.private = pp;
	227	pd = parport_register_dev_model(p, "spi_butterfly", &butterfly_cb, 0);
2e10c84b DB	228	if (!pd) {
	229	status = -ENOMEM;
	230	goto clean0;
	231	}
	232	pp->pd = pd;
	233
	234	status = parport_claim(pd);
	235	if (status < 0)
	236	goto clean1;
	237
	238	/*
	239	* Butterfly reset, powerup, run firmware
	240	*/
	241	pr_debug("%s: powerup/reset Butterfly\n", p->name);
	242
	243	/* nCS for dataflash (this bit is inverted on output) */
	244	parport_frob_control(pp->port, spi_cs_bit, 0);
	245
	246	/* stabilize power with chip in reset (nRESET), and
735ce95e	247	* spi_sck_bit clear (CPOL=0)
2e10c84b DB	248	*/
	249	pp->lastbyte \|= vcc_bits;
	250	parport_write_data(pp->port, pp->lastbyte);
	251	msleep(5);
	252
	253	/* take it out of reset; assume long reset delay */
	254	pp->lastbyte \|= butterfly_nreset;
	255	parport_write_data(pp->port, pp->lastbyte);
	256	msleep(100);
	257
2e10c84b DB	258	/*
	259	* Start SPI ... for now, hide that we're two physical busses.
	260	*/
	261	status = spi_bitbang_start(&pp->bitbang);
	262	if (status < 0)
	263	goto clean2;
	264
9c1da3cb DB	265	/* Bus 1 lets us talk to at45db041b (firmware disables AVR SPI), AVR
	266	* (firmware resets at45, acts as spi slave) or neither (we ignore
	267	* both, AVR uses AT45). Here we expect firmware for the first option.
2e10c84b	268	*/
1fc7547d	269
2e10c84b DB	270	pp->info[0].max_speed_hz = 15 * 1000 * 1000;
	271	strcpy(pp->info[0].modalias, "mtd_dataflash");
	272	pp->info[0].platform_data = &flash;
	273	pp->info[0].chip_select = 1;
	274	pp->info[0].controller_data = pp;
	275	pp->dataflash = spi_new_device(pp->bitbang.master, &pp->info[0]);
	276	if (pp->dataflash)
	277	pr_debug("%s: dataflash at %s\n", p->name,
e71fec73	278	dev_name(&pp->dataflash->dev));
2e10c84b	279
2e10c84b DB	280	pr_info("%s: AVR Butterfly\n", p->name);
	281	butterfly = pp;
	282	return;
	283
	284	clean2:
	285	/* turn off VCC */
	286	parport_write_data(pp->port, 0);
	287
	288	parport_release(pp->pd);
	289	clean1:
	290	parport_unregister_device(pd);
	291	clean0:
b12fe725	292	spi_master_put(pp->bitbang.master);
2e10c84b	293	done:
2e10c84b DB	294	pr_debug("%s: butterfly probe, fail %d\n", p->name, status);
	295	}
	296
	297	static void butterfly_detach(struct parport *p)
	298	{
	299	struct butterfly *pp;
2e10c84b DB	300
	301	/* FIXME this global is ugly ... but, how to quickly get from
	302	* the parport to the "struct butterfly" associated with it?
	303	* "old school" driver-internal device lists?
	304	*/
	305	if (!butterfly \|\| butterfly->port != p)
	306	return;
	307	pp = butterfly;
	308	butterfly = NULL;
	309
9c1da3cb	310	/* stop() unregisters child devices too */
d9721ae1	311	spi_bitbang_stop(&pp->bitbang);
2e10c84b DB	312
	313	/* turn off VCC */
	314	parport_write_data(pp->port, 0);
	315	msleep(10);
	316
	317	parport_release(pp->pd);
	318	parport_unregister_device(pp->pd);
	319
b12fe725	320	spi_master_put(pp->bitbang.master);
2e10c84b DB	321	}
	322
	323	static struct parport_driver butterfly_driver = {
	324	.name = "spi_butterfly",
1d3029cc	325	.match_port = butterfly_attach,
2e10c84b	326	.detach = butterfly_detach,
1d3029cc	327	.devmodel = true,
2e10c84b DB	328	};
2e10c84b DB	329
2e10c84b DB	330	static int __init butterfly_init(void)
	331	{
	332	return parport_register_driver(&butterfly_driver);
	333	}
	334	device_initcall(butterfly_init);
	335
	336	static void __exit butterfly_exit(void)
	337	{
	338	parport_unregister_driver(&butterfly_driver);
	339	}
	340	module_exit(butterfly_exit);
	341
9c1da3cb	342	MODULE_DESCRIPTION("Parport Adapter driver for AVR Butterfly");
2e10c84b	343	MODULE_LICENSE("GPL");