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

// SPDX-License-Identifier: GPL-2.0-only
/*
 *	w1_ds2433.c - w1 family 23 (DS2433) driver
 *
 * Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com>
 */

#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 <linux/w1.h>

#define W1_EEPROM_DS2433	0x23

#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);

MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
MODULE_DESCRIPTION("w1 family 23 driver for DS2433, 4kb EEPROM");
MODULE_LICENSE("GPL");
MODULE_ALIAS("w1-family-" __stringify(W1_EEPROM_DS2433));
Commit	Line	Data
40b0b3f8	1	// SPDX-License-Identifier: GPL-2.0-only
80895392 EP	2	/*
	3	* w1_ds2433.c - w1 family 23 (DS2433) driver
	4	*
	5	* Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com>
80895392 EP	6	*/
	7
	8	#include <linux/kernel.h>
	9	#include <linux/module.h>
	10	#include <linux/moduleparam.h>
	11	#include <linux/device.h>
	12	#include <linux/types.h>
	13	#include <linux/delay.h>
5a0e3ad6	14	#include <linux/slab.h>
e9d55f9d	15	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
0a25e4d5	16	#include <linux/crc16.h>
f24ec7f6 EP	17
	18	#define CRC16_INIT 0
	19	#define CRC16_VALID 0xb001
	20
0a25e4d5	21	#endif
80895392	22
de0d6dbd AD	23	#include <linux/w1.h>
	24
	25	#define W1_EEPROM_DS2433 0x23
80895392	26
80895392	27	#define W1_EEPROM_SIZE 512
0a25e4d5	28	#define W1_PAGE_COUNT 16
80895392 EP	29	#define W1_PAGE_SIZE 32
	30	#define W1_PAGE_BITS 5
	31	#define W1_PAGE_MASK 0x1F
	32
0a25e4d5 EP	33	#define W1_F23_TIME 300
0a25e4d5 EP	34
80895392 EP	35	#define W1_F23_READ_EEPROM 0xF0
	36	#define W1_F23_WRITE_SCRATCH 0x0F
	37	#define W1_F23_READ_SCRATCH 0xAA
	38	#define W1_F23_COPY_SCRATCH 0x55
	39
0a25e4d5 EP	40	struct w1_f23_data {
	41	u8 memory[W1_EEPROM_SIZE];
	42	u32 validcrc;
	43	};
	44
80895392 EP	45	/**
80895392 EP	46	* Check the file size bounds and adjusts count as needed.
0a25e4d5	47	* This would not be needed if the file size didn't reset to 0 after a write.
80895392 EP	48	*/
	49	static inline size_t w1_f23_fix_count(loff_t off, size_t count, size_t size)
	50	{
	51	if (off > size)
	52	return 0;
	53
	54	if ((off + count) > size)
	55	return (size - off);
	56
	57	return count;
	58	}
	59
e9d55f9d	60	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
0a25e4d5 EP	61	static int w1_f23_refresh_block(struct w1_slave sl, struct w1_f23_data data,
	62	int block)
	63	{
	64	u8 wrbuf[3];
	65	int off = block * W1_PAGE_SIZE;
	66
	67	if (data->validcrc & (1 << block))
	68	return 0;
	69
	70	if (w1_reset_select_slave(sl)) {
	71	data->validcrc = 0;
	72	return -EIO;
	73	}
	74
	75	wrbuf[0] = W1_F23_READ_EEPROM;
	76	wrbuf[1] = off & 0xff;
	77	wrbuf[2] = off >> 8;
	78	w1_write_block(sl->master, wrbuf, 3);
	79	w1_read_block(sl->master, &data->memory[off], W1_PAGE_SIZE);
	80
	81	/* cache the block if the CRC is valid */
	82	if (crc16(CRC16_INIT, &data->memory[off], W1_PAGE_SIZE) == CRC16_VALID)
	83	data->validcrc \|= (1 << block);
	84
	85	return 0;
	86	}
e9d55f9d	87	#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
0a25e4d5	88
38f40982 GKH	89	static ssize_t eeprom_read(struct file filp, struct kobject kobj,
	90	struct bin_attribute bin_attr, char buf,
	91	loff_t off, size_t count)
80895392 EP	92	{
80895392 EP	93	struct w1_slave *sl = kobj_to_w1_slave(kobj);
e9d55f9d	94	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
0a25e4d5 EP	95	struct w1_f23_data *data = sl->family_data;
	96	int i, min_page, max_page;
	97	#else
80895392	98	u8 wrbuf[3];
0a25e4d5	99	#endif
80895392 EP	100
	101	if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
	102	return 0;
	103
b02f8bed	104	mutex_lock(&sl->master->bus_mutex);
80895392	105
e9d55f9d	106	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
0a25e4d5 EP	107
	108	min_page = (off >> W1_PAGE_BITS);
	109	max_page = (off + count - 1) >> W1_PAGE_BITS;
	110	for (i = min_page; i <= max_page; i++) {
	111	if (w1_f23_refresh_block(sl, data, i)) {
	112	count = -EIO;
	113	goto out_up;
	114	}
	115	}
	116	memcpy(buf, &data->memory[off], count);
	117
e9d55f9d	118	#else /* CONFIG_W1_SLAVE_DS2433_CRC */
0a25e4d5	119
80895392 EP	120	/* read directly from the EEPROM */
	121	if (w1_reset_select_slave(sl)) {
	122	count = -EIO;
	123	goto out_up;
	124	}
	125
	126	wrbuf[0] = W1_F23_READ_EEPROM;
	127	wrbuf[1] = off & 0xff;
	128	wrbuf[2] = off >> 8;
	129	w1_write_block(sl->master, wrbuf, 3);
	130	w1_read_block(sl->master, buf, count);
	131
e9d55f9d	132	#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
0a25e4d5	133
80895392	134	out_up:
b02f8bed	135	mutex_unlock(&sl->master->bus_mutex);
80895392 EP	136
	137	return count;
	138	}
	139
	140	/**
	141	* Writes to the scratchpad and reads it back for verification.
0a25e4d5 EP	142	* Then copies the scratchpad to EEPROM.
0a25e4d5 EP	143	* The data must be on one page.
80895392 EP	144	* The master must be locked.
	145	*
	146	* @param sl The slave structure
	147	* @param addr Address for the write
	148	* @param len length must be <= (W1_PAGE_SIZE - (addr & W1_PAGE_MASK))
	149	* @param data The data to write
	150	* @return 0=Success -1=failure
	151	*/
	152	static int w1_f23_write(struct w1_slave sl, int addr, int len, const u8 data)
	153	{
dca17146 BG	154	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
	155	struct w1_f23_data *f23 = sl->family_data;
	156	#endif
80895392 EP	157	u8 wrbuf[4];
	158	u8 rdbuf[W1_PAGE_SIZE + 3];
	159	u8 es = (addr + len - 1) & 0x1f;
	160
	161	/* Write the data to the scratchpad */
	162	if (w1_reset_select_slave(sl))
	163	return -1;
	164
	165	wrbuf[0] = W1_F23_WRITE_SCRATCH;
	166	wrbuf[1] = addr & 0xff;
	167	wrbuf[2] = addr >> 8;
	168
	169	w1_write_block(sl->master, wrbuf, 3);
	170	w1_write_block(sl->master, data, len);
	171
	172	/* Read the scratchpad and verify */
	173	if (w1_reset_select_slave(sl))
	174	return -1;
	175
	176	w1_write_8(sl->master, W1_F23_READ_SCRATCH);
	177	w1_read_block(sl->master, rdbuf, len + 3);
	178
	179	/* Compare what was read against the data written */
	180	if ((rdbuf[0] != wrbuf[1]) \|\| (rdbuf[1] != wrbuf[2]) \|\|
	181	(rdbuf[2] != es) \|\| (memcmp(data, &rdbuf[3], len) != 0))
	182	return -1;
	183
	184	/* Copy the scratchpad to EEPROM */
	185	if (w1_reset_select_slave(sl))
	186	return -1;
	187
	188	wrbuf[0] = W1_F23_COPY_SCRATCH;
	189	wrbuf[3] = es;
	190	w1_write_block(sl->master, wrbuf, 4);
	191
	192	/* Sleep for 5 ms to wait for the write to complete */
	193	msleep(5);
	194
	195	/* Reset the bus to wake up the EEPROM (this may not be needed) */
	196	w1_reset_bus(sl->master);
dca17146 BG	197	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
	198	f23->validcrc &= ~(1 << (addr >> W1_PAGE_BITS));
	199	#endif
80895392 EP	200	return 0;
	201	}
	202
38f40982 GKH	203	static ssize_t eeprom_write(struct file filp, struct kobject kobj,
	204	struct bin_attribute bin_attr, char buf,
	205	loff_t off, size_t count)
80895392 EP	206	{
	207	struct w1_slave *sl = kobj_to_w1_slave(kobj);
	208	int addr, len, idx;
	209
	210	if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
	211	return 0;
	212
e9d55f9d	213	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
0a25e4d5 EP	214	/* can only write full blocks in cached mode */
0a25e4d5 EP	215	if ((off & W1_PAGE_MASK) \|\| (count & W1_PAGE_MASK)) {
f24ec7f6	216	dev_err(&sl->dev, "invalid offset/count off=%d cnt=%zd\n",
0a25e4d5 EP	217	(int)off, count);
	218	return -EINVAL;
	219	}
	220
	221	/* make sure the block CRCs are valid */
	222	for (idx = 0; idx < count; idx += W1_PAGE_SIZE) {
	223	if (crc16(CRC16_INIT, &buf[idx], W1_PAGE_SIZE) != CRC16_VALID) {
	224	dev_err(&sl->dev, "bad CRC at offset %d\n", (int)off);
	225	return -EINVAL;
	226	}
	227	}
e9d55f9d	228	#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
0a25e4d5	229
b02f8bed	230	mutex_lock(&sl->master->bus_mutex);
80895392 EP	231
	232	/* Can only write data to one page at a time */
	233	idx = 0;
	234	while (idx < count) {
	235	addr = off + idx;
	236	len = W1_PAGE_SIZE - (addr & W1_PAGE_MASK);
	237	if (len > (count - idx))
	238	len = count - idx;
	239
	240	if (w1_f23_write(sl, addr, len, &buf[idx]) < 0) {
	241	count = -EIO;
	242	goto out_up;
	243	}
	244	idx += len;
	245	}
	246
	247	out_up:
b02f8bed	248	mutex_unlock(&sl->master->bus_mutex);
80895392 EP	249
	250	return count;
	251	}
	252
38f40982 GKH	253	static BIN_ATTR_RW(eeprom, W1_EEPROM_SIZE);
	254
	255	static struct bin_attribute *w1_f23_bin_attributes[] = {
	256	&bin_attr_eeprom,
	257	NULL,
	258	};
	259
	260	static const struct attribute_group w1_f23_group = {
	261	.bin_attrs = w1_f23_bin_attributes,
	262	};
	263
	264	static const struct attribute_group *w1_f23_groups[] = {
	265	&w1_f23_group,
	266	NULL,
80895392 EP	267	};
	268
	269	static int w1_f23_add_slave(struct w1_slave *sl)
	270	{
e9d55f9d	271	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
0a25e4d5 EP	272	struct w1_f23_data *data;
0a25e4d5 EP	273
dd00cc48	274	data = kzalloc(sizeof(struct w1_f23_data), GFP_KERNEL);
0a25e4d5 EP	275	if (!data)
0a25e4d5 EP	276	return -ENOMEM;
0a25e4d5 EP	277	sl->family_data = data;
0a25e4d5 EP	278
e9d55f9d	279	#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
38f40982	280	return 0;
80895392 EP	281	}
	282
	283	static void w1_f23_remove_slave(struct w1_slave *sl)
	284	{
e9d55f9d	285	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
6044ec88 JJ	286	kfree(sl->family_data);
6044ec88 JJ	287	sl->family_data = NULL;
e9d55f9d	288	#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
80895392 EP	289	}
	290
	291	static struct w1_family_ops w1_f23_fops = {
	292	.add_slave = w1_f23_add_slave,
	293	.remove_slave = w1_f23_remove_slave,
38f40982	294	.groups = w1_f23_groups,
80895392 EP	295	};
	296
	297	static struct w1_family w1_family_23 = {
	298	.fid = W1_EEPROM_DS2433,
	299	.fops = &w1_f23_fops,
	300	};
939fc832	301	module_w1_family(w1_family_23);
50fa2951 AD	302
	303	MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
	304	MODULE_DESCRIPTION("w1 family 23 driver for DS2433, 4kb EEPROM");
	305	MODULE_LICENSE("GPL");
	306	MODULE_ALIAS("w1-family-" __stringify(W1_EEPROM_DS2433));