[mirror_ubuntu-zesty-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>
#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");

#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 w1_f23_read_bin(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->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->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)
{
	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);

	return 0;
}

static ssize_t w1_f23_write_bin(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->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->mutex);

	return count;
}

static struct bin_attribute w1_f23_bin_attr = {
	.attr = {
		.name = "eeprom",
		.mode = S_IRUGO | S_IWUSR,
	},
	.size = W1_EEPROM_SIZE,
	.read = w1_f23_read_bin,
	.write = w1_f23_write_bin,
};

static int w1_f23_add_slave(struct w1_slave *sl)
{
	int err;
#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 */

	err = sysfs_create_bin_file(&sl->dev.kobj, &w1_f23_bin_attr);

#ifdef CONFIG_W1_SLAVE_DS2433_CRC
	if (err)
		kfree(data);
#endif	/* CONFIG_W1_SLAVE_DS2433_CRC */

	return err;
}

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 */
	sysfs_remove_bin_file(&sl->dev.kobj, &w1_f23_bin_attr);
}

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

static struct w1_family w1_family_23 = {
	.fid = W1_EEPROM_DS2433,
	.fops = &w1_f23_fops,
};

static int __init w1_f23_init(void)
{
	return w1_register_family(&w1_family_23);
}

static void __exit w1_f23_fini(void)
{
	w1_unregister_family(&w1_family_23);
}

module_init(w1_f23_init);
module_exit(w1_f23_fini);
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>
e9d55f9d	16	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
0a25e4d5	17	#include <linux/crc16.h>
f24ec7f6 EP	18
	19	#define CRC16_INIT 0
	20	#define CRC16_VALID 0xb001
	21
0a25e4d5	22	#endif
80895392	23
bd529cfb	24	#include "../w1.h"
bd529cfb EP	25	#include "../w1_int.h"
bd529cfb EP	26	#include "../w1_family.h"
80895392 EP	27
	28	MODULE_LICENSE("GPL");
	29	MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
	30	MODULE_DESCRIPTION("w1 family 23 driver for DS2433, 4kb EEPROM");
	31
	32	#define W1_EEPROM_SIZE 512
0a25e4d5	33	#define W1_PAGE_COUNT 16
80895392 EP	34	#define W1_PAGE_SIZE 32
	35	#define W1_PAGE_BITS 5
	36	#define W1_PAGE_MASK 0x1F
	37
0a25e4d5 EP	38	#define W1_F23_TIME 300
0a25e4d5 EP	39
80895392 EP	40	#define W1_F23_READ_EEPROM 0xF0
	41	#define W1_F23_WRITE_SCRATCH 0x0F
	42	#define W1_F23_READ_SCRATCH 0xAA
	43	#define W1_F23_COPY_SCRATCH 0x55
	44
0a25e4d5 EP	45	struct w1_f23_data {
	46	u8 memory[W1_EEPROM_SIZE];
	47	u32 validcrc;
	48	};
	49
80895392 EP	50	/**
80895392 EP	51	* Check the file size bounds and adjusts count as needed.
0a25e4d5	52	* This would not be needed if the file size didn't reset to 0 after a write.
80895392 EP	53	*/
	54	static inline size_t w1_f23_fix_count(loff_t off, size_t count, size_t size)
	55	{
	56	if (off > size)
	57	return 0;
	58
	59	if ((off + count) > size)
	60	return (size - off);
	61
	62	return count;
	63	}
	64
e9d55f9d	65	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
0a25e4d5 EP	66	static int w1_f23_refresh_block(struct w1_slave sl, struct w1_f23_data data,
	67	int block)
	68	{
	69	u8 wrbuf[3];
	70	int off = block * W1_PAGE_SIZE;
	71
	72	if (data->validcrc & (1 << block))
	73	return 0;
	74
	75	if (w1_reset_select_slave(sl)) {
	76	data->validcrc = 0;
	77	return -EIO;
	78	}
	79
	80	wrbuf[0] = W1_F23_READ_EEPROM;
	81	wrbuf[1] = off & 0xff;
	82	wrbuf[2] = off >> 8;
	83	w1_write_block(sl->master, wrbuf, 3);
	84	w1_read_block(sl->master, &data->memory[off], W1_PAGE_SIZE);
	85
	86	/* cache the block if the CRC is valid */
	87	if (crc16(CRC16_INIT, &data->memory[off], W1_PAGE_SIZE) == CRC16_VALID)
	88	data->validcrc \|= (1 << block);
	89
	90	return 0;
	91	}
e9d55f9d	92	#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
0a25e4d5	93
91a69029 ZR	94	static ssize_t w1_f23_read_bin(struct kobject *kobj,
	95	struct bin_attribute *bin_attr,
	96	char *buf, loff_t off, size_t count)
80895392 EP	97	{
80895392 EP	98	struct w1_slave *sl = kobj_to_w1_slave(kobj);
e9d55f9d	99	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
0a25e4d5 EP	100	struct w1_f23_data *data = sl->family_data;
	101	int i, min_page, max_page;
	102	#else
80895392	103	u8 wrbuf[3];
0a25e4d5	104	#endif
80895392 EP	105
	106	if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
	107	return 0;
	108
abd52a13	109	mutex_lock(&sl->master->mutex);
80895392	110
e9d55f9d	111	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
0a25e4d5 EP	112
	113	min_page = (off >> W1_PAGE_BITS);
	114	max_page = (off + count - 1) >> W1_PAGE_BITS;
	115	for (i = min_page; i <= max_page; i++) {
	116	if (w1_f23_refresh_block(sl, data, i)) {
	117	count = -EIO;
	118	goto out_up;
	119	}
	120	}
	121	memcpy(buf, &data->memory[off], count);
	122
e9d55f9d	123	#else /* CONFIG_W1_SLAVE_DS2433_CRC */
0a25e4d5	124
80895392 EP	125	/* read directly from the EEPROM */
	126	if (w1_reset_select_slave(sl)) {
	127	count = -EIO;
	128	goto out_up;
	129	}
	130
	131	wrbuf[0] = W1_F23_READ_EEPROM;
	132	wrbuf[1] = off & 0xff;
	133	wrbuf[2] = off >> 8;
	134	w1_write_block(sl->master, wrbuf, 3);
	135	w1_read_block(sl->master, buf, count);
	136
e9d55f9d	137	#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
0a25e4d5	138
80895392	139	out_up:
abd52a13	140	mutex_unlock(&sl->master->mutex);
80895392 EP	141
	142	return count;
	143	}
	144
	145	/**
	146	* Writes to the scratchpad and reads it back for verification.
0a25e4d5 EP	147	* Then copies the scratchpad to EEPROM.
0a25e4d5 EP	148	* The data must be on one page.
80895392 EP	149	* The master must be locked.
	150	*
	151	* @param sl The slave structure
	152	* @param addr Address for the write
	153	* @param len length must be <= (W1_PAGE_SIZE - (addr & W1_PAGE_MASK))
	154	* @param data The data to write
	155	* @return 0=Success -1=failure
	156	*/
	157	static int w1_f23_write(struct w1_slave sl, int addr, int len, const u8 data)
	158	{
	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);
	199
	200	return 0;
	201	}
	202
91a69029 ZR	203	static ssize_t w1_f23_write_bin(struct kobject *kobj,
	204	struct bin_attribute *bin_attr,
	205	char *buf, 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
abd52a13	230	mutex_lock(&sl->master->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:
abd52a13	248	mutex_unlock(&sl->master->mutex);
80895392 EP	249
	250	return count;
	251	}
	252
	253	static struct bin_attribute w1_f23_bin_attr = {
	254	.attr = {
	255	.name = "eeprom",
	256	.mode = S_IRUGO \| S_IWUSR,
80895392 EP	257	},
	258	.size = W1_EEPROM_SIZE,
	259	.read = w1_f23_read_bin,
	260	.write = w1_f23_write_bin,
	261	};
	262
	263	static int w1_f23_add_slave(struct w1_slave *sl)
	264	{
0a25e4d5	265	int err;
e9d55f9d	266	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
0a25e4d5 EP	267	struct w1_f23_data *data;
0a25e4d5 EP	268
dd00cc48	269	data = kzalloc(sizeof(struct w1_f23_data), GFP_KERNEL);
0a25e4d5 EP	270	if (!data)
0a25e4d5 EP	271	return -ENOMEM;
0a25e4d5 EP	272	sl->family_data = data;
0a25e4d5 EP	273
e9d55f9d	274	#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
0a25e4d5 EP	275
	276	err = sysfs_create_bin_file(&sl->dev.kobj, &w1_f23_bin_attr);
	277
e9d55f9d	278	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
0a25e4d5 EP	279	if (err)
0a25e4d5 EP	280	kfree(data);
e9d55f9d	281	#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
0a25e4d5 EP	282
0a25e4d5 EP	283	return err;
80895392 EP	284	}
	285
	286	static void w1_f23_remove_slave(struct w1_slave *sl)
	287	{
e9d55f9d	288	#ifdef CONFIG_W1_SLAVE_DS2433_CRC
6044ec88 JJ	289	kfree(sl->family_data);
6044ec88 JJ	290	sl->family_data = NULL;
e9d55f9d	291	#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
80895392 EP	292	sysfs_remove_bin_file(&sl->dev.kobj, &w1_f23_bin_attr);
	293	}
	294
	295	static struct w1_family_ops w1_f23_fops = {
	296	.add_slave = w1_f23_add_slave,
	297	.remove_slave = w1_f23_remove_slave,
	298	};
	299
	300	static struct w1_family w1_family_23 = {
	301	.fid = W1_EEPROM_DS2433,
	302	.fops = &w1_f23_fops,
	303	};
	304
	305	static int __init w1_f23_init(void)
	306	{
	307	return w1_register_family(&w1_family_23);
	308	}
	309
	310	static void __exit w1_f23_fini(void)
	311	{
	312	w1_unregister_family(&w1_family_23);
	313	}
	314
	315	module_init(w1_f23_init);
	316	module_exit(w1_f23_fini);