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