[linux-2.6-block.git] / drivers / w1 / slaves / w1_ds2433.c

/*
 *	w1_ds2433.c - w1 family 23 (DS2433) driver
 *
 * Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com>
 *
 * This source code is licensed under the GNU General Public License,
 * Version 2. See the file COPYING for more details.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/device.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/slab.h>
#ifdef CONFIG_W1_SLAVE_DS2433_CRC
#include <linux/crc16.h>

#define CRC16_INIT		0
#define CRC16_VALID		0xb001

#endif

#include "../w1.h"
#include "../w1_int.h"
#include "../w1_family.h"

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
MODULE_DESCRIPTION("w1 family 23 driver for DS2433, 4kb EEPROM");
MODULE_ALIAS("w1-family-" __stringify(W1_EEPROM_DS2433));

#define W1_EEPROM_SIZE		512
#define W1_PAGE_COUNT		16
#define W1_PAGE_SIZE		32
#define W1_PAGE_BITS		5
#define W1_PAGE_MASK		0x1F

#define W1_F23_TIME		300

#define W1_F23_READ_EEPROM	0xF0
#define W1_F23_WRITE_SCRATCH	0x0F
#define W1_F23_READ_SCRATCH	0xAA
#define W1_F23_COPY_SCRATCH	0x55

struct w1_f23_data {
	u8	memory[W1_EEPROM_SIZE];
	u32	validcrc;
};

/**
 * Check the file size bounds and adjusts count as needed.
 * This would not be needed if the file size didn't reset to 0 after a write.
 */
static inline size_t w1_f23_fix_count(loff_t off, size_t count, size_t size)
{
	if (off > size)
		return 0;

	if ((off + count) > size)
		return (size - off);

	return count;
}

#ifdef CONFIG_W1_SLAVE_DS2433_CRC
static int w1_f23_refresh_block(struct w1_slave *sl, struct w1_f23_data *data,
				int block)
{
	u8	wrbuf[3];
	int	off = block * W1_PAGE_SIZE;

	if (data->validcrc & (1 << block))
		return 0;

	if (w1_reset_select_slave(sl)) {
		data->validcrc = 0;
		return -EIO;
	}

	wrbuf[0] = W1_F23_READ_EEPROM;
	wrbuf[1] = off & 0xff;
	wrbuf[2] = off >> 8;
	w1_write_block(sl->master, wrbuf, 3);
	w1_read_block(sl->master, &data->memory[off], W1_PAGE_SIZE);

	/* cache the block if the CRC is valid */
	if (crc16(CRC16_INIT, &data->memory[off], W1_PAGE_SIZE) == CRC16_VALID)
		data->validcrc |= (1 << block);

	return 0;
}
#endif	/* CONFIG_W1_SLAVE_DS2433_CRC */

static ssize_t eeprom_read(struct file *filp, struct kobject *kobj,
			   struct bin_attribute *bin_attr, char *buf,
			   loff_t off, size_t count)
{
	struct w1_slave *sl = kobj_to_w1_slave(kobj);
#ifdef CONFIG_W1_SLAVE_DS2433_CRC
	struct w1_f23_data *data = sl->family_data;
	int i, min_page, max_page;
#else
	u8 wrbuf[3];
#endif

	if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
		return 0;

	mutex_lock(&sl->master->bus_mutex);

#ifdef CONFIG_W1_SLAVE_DS2433_CRC

	min_page = (off >> W1_PAGE_BITS);
	max_page = (off + count - 1) >> W1_PAGE_BITS;
	for (i = min_page; i <= max_page; i++) {
		if (w1_f23_refresh_block(sl, data, i)) {
			count = -EIO;
			goto out_up;
		}
	}
	memcpy(buf, &data->memory[off], count);

#else 	/* CONFIG_W1_SLAVE_DS2433_CRC */

	/* read directly from the EEPROM */
	if (w1_reset_select_slave(sl)) {
		count = -EIO;
		goto out_up;
	}

	wrbuf[0] = W1_F23_READ_EEPROM;
	wrbuf[1] = off & 0xff;
	wrbuf[2] = off >> 8;
	w1_write_block(sl->master, wrbuf, 3);
	w1_read_block(sl->master, buf, count);

#endif	/* CONFIG_W1_SLAVE_DS2433_CRC */

out_up:
	mutex_unlock(&sl->master->bus_mutex);

	return count;
}

/**
 * Writes to the scratchpad and reads it back for verification.
 * Then copies the scratchpad to EEPROM.
 * The data must be on one page.
 * The master must be locked.
 *
 * @param sl	The slave structure
 * @param addr	Address for the write
 * @param len   length must be <= (W1_PAGE_SIZE - (addr & W1_PAGE_MASK))
 * @param data	The data to write
 * @return	0=Success -1=failure
 */
static int w1_f23_write(struct w1_slave *sl, int addr, int len, const u8 *data)
{
#ifdef CONFIG_W1_SLAVE_DS2433_CRC
	struct w1_f23_data *f23 = sl->family_data;
#endif
	u8 wrbuf[4];
	u8 rdbuf[W1_PAGE_SIZE + 3];
	u8 es = (addr + len - 1) & 0x1f;

	/* Write the data to the scratchpad */
	if (w1_reset_select_slave(sl))
		return -1;

	wrbuf[0] = W1_F23_WRITE_SCRATCH;
	wrbuf[1] = addr & 0xff;
	wrbuf[2] = addr >> 8;

	w1_write_block(sl->master, wrbuf, 3);
	w1_write_block(sl->master, data, len);

	/* Read the scratchpad and verify */
	if (w1_reset_select_slave(sl))
		return -1;

	w1_write_8(sl->master, W1_F23_READ_SCRATCH);
	w1_read_block(sl->master, rdbuf, len + 3);

	/* Compare what was read against the data written */
	if ((rdbuf[0] != wrbuf[1]) || (rdbuf[1] != wrbuf[2]) ||
	    (rdbuf[2] != es) || (memcmp(data, &rdbuf[3], len) != 0))
		return -1;

	/* Copy the scratchpad to EEPROM */
	if (w1_reset_select_slave(sl))
		return -1;

	wrbuf[0] = W1_F23_COPY_SCRATCH;
	wrbuf[3] = es;
	w1_write_block(sl->master, wrbuf, 4);

	/* Sleep for 5 ms to wait for the write to complete */
	msleep(5);

	/* Reset the bus to wake up the EEPROM (this may not be needed) */
	w1_reset_bus(sl->master);
#ifdef CONFIG_W1_SLAVE_DS2433_CRC
	f23->validcrc &= ~(1 << (addr >> W1_PAGE_BITS));
#endif
	return 0;
}

static ssize_t eeprom_write(struct file *filp, struct kobject *kobj,
			    struct bin_attribute *bin_attr, char *buf,
			    loff_t off, size_t count)
{
	struct w1_slave *sl = kobj_to_w1_slave(kobj);
	int addr, len, idx;

	if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
		return 0;

#ifdef CONFIG_W1_SLAVE_DS2433_CRC
	/* can only write full blocks in cached mode */
	if ((off & W1_PAGE_MASK) || (count & W1_PAGE_MASK)) {
		dev_err(&sl->dev, "invalid offset/count off=%d cnt=%zd\n",
			(int)off, count);
		return -EINVAL;
	}

	/* make sure the block CRCs are valid */
	for (idx = 0; idx < count; idx += W1_PAGE_SIZE) {
		if (crc16(CRC16_INIT, &buf[idx], W1_PAGE_SIZE) != CRC16_VALID) {
			dev_err(&sl->dev, "bad CRC at offset %d\n", (int)off);
			return -EINVAL;
		}
	}
#endif	/* CONFIG_W1_SLAVE_DS2433_CRC */

	mutex_lock(&sl->master->bus_mutex);

	/* Can only write data to one page at a time */
	idx = 0;
	while (idx < count) {
		addr = off + idx;
		len = W1_PAGE_SIZE - (addr & W1_PAGE_MASK);
		if (len > (count - idx))
			len = count - idx;

		if (w1_f23_write(sl, addr, len, &buf[idx]) < 0) {
			count = -EIO;
			goto out_up;
		}
		idx += len;
	}

out_up:
	mutex_unlock(&sl->master->bus_mutex);

	return count;
}

static BIN_ATTR_RW(eeprom, W1_EEPROM_SIZE);

static struct bin_attribute *w1_f23_bin_attributes[] = {
	&bin_attr_eeprom,
	NULL,
};

static const struct attribute_group w1_f23_group = {
	.bin_attrs = w1_f23_bin_attributes,
};

static const struct attribute_group *w1_f23_groups[] = {
	&w1_f23_group,
	NULL,
};

static int w1_f23_add_slave(struct w1_slave *sl)
{
#ifdef CONFIG_W1_SLAVE_DS2433_CRC
	struct w1_f23_data *data;

	data = kzalloc(sizeof(struct w1_f23_data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;
	sl->family_data = data;

#endif	/* CONFIG_W1_SLAVE_DS2433_CRC */
	return 0;
}

static void w1_f23_remove_slave(struct w1_slave *sl)
{
#ifdef CONFIG_W1_SLAVE_DS2433_CRC
	kfree(sl->family_data);
	sl->family_data = NULL;
#endif	/* CONFIG_W1_SLAVE_DS2433_CRC */
}

static struct w1_family_ops w1_f23_fops = {
	.add_slave      = w1_f23_add_slave,
	.remove_slave   = w1_f23_remove_slave,
	.groups		= w1_f23_groups,
};

static struct w1_family w1_family_23 = {
	.fid = W1_EEPROM_DS2433,
	.fops = &w1_f23_fops,
};
module_w1_family(w1_family_23);
Commit	Line	Data
80895392 EP	1	/*
	2	* w1_ds2433.c - w1 family 23 (DS2433) driver
	3	*
	4	* Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com>
	5	*
0a25e4d5 EP	6	* This source code is licensed under the GNU General Public License,
0a25e4d5 EP	7	* Version 2. See the file COPYING for more details.
80895392 EP	8	*/
	9
	10	#include <linux/kernel.h>
	11	#include <linux/module.h>
	12	#include <linux/moduleparam.h>
	13	#include <linux/device.h>
	14	#include <linux/types.h>
	15	#include <linux/delay.h>
5a0e3ad6	16	#include <linux/slab.h>
e9d55f9d	17	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
0a25e4d5	18	#include <linux/crc16.h>
f24ec7f6 EP	19
	20	#define CRC16_INIT 0
	21	#define CRC16_VALID 0xb001
	22
0a25e4d5	23	#endif
80895392	24
bd529cfb	25	#include "../w1.h"
bd529cfb EP	26	#include "../w1_int.h"
bd529cfb EP	27	#include "../w1_family.h"
80895392 EP	28
	29	MODULE_LICENSE("GPL");
	30	MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
	31	MODULE_DESCRIPTION("w1 family 23 driver for DS2433, 4kb EEPROM");
8d7bda51	32	MODULE_ALIAS("w1-family-" __stringify(W1_EEPROM_DS2433));
80895392 EP	33
80895392 EP	34	#define W1_EEPROM_SIZE 512
0a25e4d5	35	#define W1_PAGE_COUNT 16
80895392 EP	36	#define W1_PAGE_SIZE 32
	37	#define W1_PAGE_BITS 5
	38	#define W1_PAGE_MASK 0x1F
	39
0a25e4d5 EP	40	#define W1_F23_TIME 300
0a25e4d5 EP	41
80895392 EP	42	#define W1_F23_READ_EEPROM 0xF0
	43	#define W1_F23_WRITE_SCRATCH 0x0F
	44	#define W1_F23_READ_SCRATCH 0xAA
	45	#define W1_F23_COPY_SCRATCH 0x55
	46
0a25e4d5 EP	47	struct w1_f23_data {
	48	u8 memory[W1_EEPROM_SIZE];
	49	u32 validcrc;
	50	};
	51
80895392 EP	52	/**
80895392 EP	53	* Check the file size bounds and adjusts count as needed.
0a25e4d5	54	* This would not be needed if the file size didn't reset to 0 after a write.
80895392 EP	55	*/
	56	static inline size_t w1_f23_fix_count(loff_t off, size_t count, size_t size)
	57	{
	58	if (off > size)
	59	return 0;
	60
	61	if ((off + count) > size)
	62	return (size - off);
	63
	64	return count;
	65	}
	66
e9d55f9d	67	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
0a25e4d5 EP	68	static int w1_f23_refresh_block(struct w1_slave sl, struct w1_f23_data data,
	69	int block)
	70	{
	71	u8 wrbuf[3];
	72	int off = block * W1_PAGE_SIZE;
	73
	74	if (data->validcrc & (1 << block))
	75	return 0;
	76
	77	if (w1_reset_select_slave(sl)) {
	78	data->validcrc = 0;
	79	return -EIO;
	80	}
	81
	82	wrbuf[0] = W1_F23_READ_EEPROM;
	83	wrbuf[1] = off & 0xff;
	84	wrbuf[2] = off >> 8;
	85	w1_write_block(sl->master, wrbuf, 3);
	86	w1_read_block(sl->master, &data->memory[off], W1_PAGE_SIZE);
	87
	88	/* cache the block if the CRC is valid */
	89	if (crc16(CRC16_INIT, &data->memory[off], W1_PAGE_SIZE) == CRC16_VALID)
	90	data->validcrc \|= (1 << block);
	91
	92	return 0;
	93	}
e9d55f9d	94	#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
0a25e4d5	95
38f40982 GKH	96	static ssize_t eeprom_read(struct file filp, struct kobject kobj,
	97	struct bin_attribute bin_attr, char buf,
	98	loff_t off, size_t count)
80895392 EP	99	{
80895392 EP	100	struct w1_slave *sl = kobj_to_w1_slave(kobj);
e9d55f9d	101	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
0a25e4d5 EP	102	struct w1_f23_data *data = sl->family_data;
	103	int i, min_page, max_page;
	104	#else
80895392	105	u8 wrbuf[3];
0a25e4d5	106	#endif
80895392 EP	107
	108	if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
	109	return 0;
	110
b02f8bed	111	mutex_lock(&sl->master->bus_mutex);
80895392	112
e9d55f9d	113	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
0a25e4d5 EP	114
	115	min_page = (off >> W1_PAGE_BITS);
	116	max_page = (off + count - 1) >> W1_PAGE_BITS;
	117	for (i = min_page; i <= max_page; i++) {
	118	if (w1_f23_refresh_block(sl, data, i)) {
	119	count = -EIO;
	120	goto out_up;
	121	}
	122	}
	123	memcpy(buf, &data->memory[off], count);
	124
e9d55f9d	125	#else /* CONFIG_W1_SLAVE_DS2433_CRC */
0a25e4d5	126
80895392 EP	127	/* read directly from the EEPROM */
	128	if (w1_reset_select_slave(sl)) {
	129	count = -EIO;
	130	goto out_up;
	131	}
	132
	133	wrbuf[0] = W1_F23_READ_EEPROM;
	134	wrbuf[1] = off & 0xff;
	135	wrbuf[2] = off >> 8;
	136	w1_write_block(sl->master, wrbuf, 3);
	137	w1_read_block(sl->master, buf, count);
	138
e9d55f9d	139	#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
0a25e4d5	140
80895392	141	out_up:
b02f8bed	142	mutex_unlock(&sl->master->bus_mutex);
80895392 EP	143
	144	return count;
	145	}
	146
	147	/**
	148	* Writes to the scratchpad and reads it back for verification.
0a25e4d5 EP	149	* Then copies the scratchpad to EEPROM.
0a25e4d5 EP	150	* The data must be on one page.
80895392 EP	151	* The master must be locked.
	152	*
	153	* @param sl The slave structure
	154	* @param addr Address for the write
	155	* @param len length must be <= (W1_PAGE_SIZE - (addr & W1_PAGE_MASK))
	156	* @param data The data to write
	157	* @return 0=Success -1=failure
	158	*/
	159	static int w1_f23_write(struct w1_slave sl, int addr, int len, const u8 data)
	160	{
dca17146 BG	161	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
	162	struct w1_f23_data *f23 = sl->family_data;
	163	#endif
80895392 EP	164	u8 wrbuf[4];
	165	u8 rdbuf[W1_PAGE_SIZE + 3];
	166	u8 es = (addr + len - 1) & 0x1f;
	167
	168	/* Write the data to the scratchpad */
	169	if (w1_reset_select_slave(sl))
	170	return -1;
	171
	172	wrbuf[0] = W1_F23_WRITE_SCRATCH;
	173	wrbuf[1] = addr & 0xff;
	174	wrbuf[2] = addr >> 8;
	175
	176	w1_write_block(sl->master, wrbuf, 3);
	177	w1_write_block(sl->master, data, len);
	178
	179	/* Read the scratchpad and verify */
	180	if (w1_reset_select_slave(sl))
	181	return -1;
	182
	183	w1_write_8(sl->master, W1_F23_READ_SCRATCH);
	184	w1_read_block(sl->master, rdbuf, len + 3);
	185
	186	/* Compare what was read against the data written */
	187	if ((rdbuf[0] != wrbuf[1]) \|\| (rdbuf[1] != wrbuf[2]) \|\|
	188	(rdbuf[2] != es) \|\| (memcmp(data, &rdbuf[3], len) != 0))
	189	return -1;
	190
	191	/* Copy the scratchpad to EEPROM */
	192	if (w1_reset_select_slave(sl))
	193	return -1;
	194
	195	wrbuf[0] = W1_F23_COPY_SCRATCH;
	196	wrbuf[3] = es;
	197	w1_write_block(sl->master, wrbuf, 4);
	198
	199	/* Sleep for 5 ms to wait for the write to complete */
	200	msleep(5);
	201
	202	/* Reset the bus to wake up the EEPROM (this may not be needed) */
	203	w1_reset_bus(sl->master);
dca17146 BG	204	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
	205	f23->validcrc &= ~(1 << (addr >> W1_PAGE_BITS));
	206	#endif
80895392 EP	207	return 0;
	208	}
	209
38f40982 GKH	210	static ssize_t eeprom_write(struct file filp, struct kobject kobj,
	211	struct bin_attribute bin_attr, char buf,
	212	loff_t off, size_t count)
80895392 EP	213	{
	214	struct w1_slave *sl = kobj_to_w1_slave(kobj);
	215	int addr, len, idx;
	216
	217	if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
	218	return 0;
	219
e9d55f9d	220	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
0a25e4d5 EP	221	/* can only write full blocks in cached mode */
0a25e4d5 EP	222	if ((off & W1_PAGE_MASK) \|\| (count & W1_PAGE_MASK)) {
f24ec7f6	223	dev_err(&sl->dev, "invalid offset/count off=%d cnt=%zd\n",
0a25e4d5 EP	224	(int)off, count);
	225	return -EINVAL;
	226	}
	227
	228	/* make sure the block CRCs are valid */
	229	for (idx = 0; idx < count; idx += W1_PAGE_SIZE) {
	230	if (crc16(CRC16_INIT, &buf[idx], W1_PAGE_SIZE) != CRC16_VALID) {
	231	dev_err(&sl->dev, "bad CRC at offset %d\n", (int)off);
	232	return -EINVAL;
	233	}
	234	}
e9d55f9d	235	#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
0a25e4d5	236
b02f8bed	237	mutex_lock(&sl->master->bus_mutex);
80895392 EP	238
	239	/* Can only write data to one page at a time */
	240	idx = 0;
	241	while (idx < count) {
	242	addr = off + idx;
	243	len = W1_PAGE_SIZE - (addr & W1_PAGE_MASK);
	244	if (len > (count - idx))
	245	len = count - idx;
	246
	247	if (w1_f23_write(sl, addr, len, &buf[idx]) < 0) {
	248	count = -EIO;
	249	goto out_up;
	250	}
	251	idx += len;
	252	}
	253
	254	out_up:
b02f8bed	255	mutex_unlock(&sl->master->bus_mutex);
80895392 EP	256
	257	return count;
	258	}
	259
38f40982 GKH	260	static BIN_ATTR_RW(eeprom, W1_EEPROM_SIZE);
	261
	262	static struct bin_attribute *w1_f23_bin_attributes[] = {
	263	&bin_attr_eeprom,
	264	NULL,
	265	};
	266
	267	static const struct attribute_group w1_f23_group = {
	268	.bin_attrs = w1_f23_bin_attributes,
	269	};
	270
	271	static const struct attribute_group *w1_f23_groups[] = {
	272	&w1_f23_group,
	273	NULL,
80895392 EP	274	};
	275
	276	static int w1_f23_add_slave(struct w1_slave *sl)
	277	{
e9d55f9d	278	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
0a25e4d5 EP	279	struct w1_f23_data *data;
0a25e4d5 EP	280
dd00cc48	281	data = kzalloc(sizeof(struct w1_f23_data), GFP_KERNEL);
0a25e4d5 EP	282	if (!data)
0a25e4d5 EP	283	return -ENOMEM;
0a25e4d5 EP	284	sl->family_data = data;
0a25e4d5 EP	285
e9d55f9d	286	#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
38f40982	287	return 0;
80895392 EP	288	}
	289
	290	static void w1_f23_remove_slave(struct w1_slave *sl)
	291	{
e9d55f9d	292	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
6044ec88 JJ	293	kfree(sl->family_data);
6044ec88 JJ	294	sl->family_data = NULL;
e9d55f9d	295	#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
80895392 EP	296	}
	297
	298	static struct w1_family_ops w1_f23_fops = {
	299	.add_slave = w1_f23_add_slave,
	300	.remove_slave = w1_f23_remove_slave,
38f40982	301	.groups = w1_f23_groups,
80895392 EP	302	};
	303
	304	static struct w1_family w1_family_23 = {
	305	.fid = W1_EEPROM_DS2433,
	306	.fops = &w1_f23_fops,
	307	};
939fc832	308	module_w1_family(w1_family_23);