2 * w1_ds2433.c - w1 family 23 (DS2433) driver
4 * Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com>
6 * This source code is licensed under the GNU General Public License,
7 * Version 2. See the file COPYING for more details.
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>
16 #ifdef CONFIG_W1_F23_CRC
17 #include <linux/crc16.h>
23 #include "w1_family.h"
25 MODULE_LICENSE("GPL");
26 MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
27 MODULE_DESCRIPTION("w1 family 23 driver for DS2433, 4kb EEPROM");
29 #define W1_EEPROM_SIZE 512
30 #define W1_PAGE_COUNT 16
31 #define W1_PAGE_SIZE 32
32 #define W1_PAGE_BITS 5
33 #define W1_PAGE_MASK 0x1F
35 #define W1_F23_TIME 300
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
43 u8 memory
[W1_EEPROM_SIZE
];
48 * Check the file size bounds and adjusts count as needed.
49 * This would not be needed if the file size didn't reset to 0 after a write.
51 static inline size_t w1_f23_fix_count(loff_t off
, size_t count
, size_t size
)
56 if ((off
+ count
) > size
)
62 #ifdef CONFIG_W1_F23_CRC
63 static int w1_f23_refresh_block(struct w1_slave
*sl
, struct w1_f23_data
*data
,
67 int off
= block
* W1_PAGE_SIZE
;
69 if (data
->validcrc
& (1 << block
))
72 if (w1_reset_select_slave(sl
)) {
77 wrbuf
[0] = W1_F23_READ_EEPROM
;
78 wrbuf
[1] = off
& 0xff;
80 w1_write_block(sl
->master
, wrbuf
, 3);
81 w1_read_block(sl
->master
, &data
->memory
[off
], W1_PAGE_SIZE
);
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
);
89 #endif /* CONFIG_W1_F23_CRC */
91 static ssize_t
w1_f23_read_bin(struct kobject
*kobj
, char *buf
, loff_t off
,
94 struct w1_slave
*sl
= kobj_to_w1_slave(kobj
);
95 #ifdef CONFIG_W1_F23_CRC
96 struct w1_f23_data
*data
= sl
->family_data
;
97 int i
, min_page
, max_page
;
102 if ((count
= w1_f23_fix_count(off
, count
, W1_EEPROM_SIZE
)) == 0)
105 atomic_inc(&sl
->refcnt
);
106 if (down_interruptible(&sl
->master
->mutex
)) {
111 #ifdef CONFIG_W1_F23_CRC
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
)) {
121 memcpy(buf
, &data
->memory
[off
], count
);
123 #else /* CONFIG_W1_F23_CRC */
125 /* read directly from the EEPROM */
126 if (w1_reset_select_slave(sl
)) {
131 wrbuf
[0] = W1_F23_READ_EEPROM
;
132 wrbuf
[1] = off
& 0xff;
134 w1_write_block(sl
->master
, wrbuf
, 3);
135 w1_read_block(sl
->master
, buf
, count
);
137 #endif /* CONFIG_W1_F23_CRC */
140 up(&sl
->master
->mutex
);
142 atomic_dec(&sl
->refcnt
);
148 * Writes to the scratchpad and reads it back for verification.
149 * Then copies the scratchpad to EEPROM.
150 * The data must be on one page.
151 * The master must be locked.
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
159 static int w1_f23_write(struct w1_slave
*sl
, int addr
, int len
, const u8
*data
)
162 u8 rdbuf
[W1_PAGE_SIZE
+ 3];
163 u8 es
= (addr
+ len
- 1) & 0x1f;
165 /* Write the data to the scratchpad */
166 if (w1_reset_select_slave(sl
))
169 wrbuf
[0] = W1_F23_WRITE_SCRATCH
;
170 wrbuf
[1] = addr
& 0xff;
171 wrbuf
[2] = addr
>> 8;
173 w1_write_block(sl
->master
, wrbuf
, 3);
174 w1_write_block(sl
->master
, data
, len
);
176 /* Read the scratchpad and verify */
177 if (w1_reset_select_slave(sl
))
180 w1_write_8(sl
->master
, W1_F23_READ_SCRATCH
);
181 w1_read_block(sl
->master
, rdbuf
, len
+ 3);
183 /* Compare what was read against the data written */
184 if ((rdbuf
[0] != wrbuf
[1]) || (rdbuf
[1] != wrbuf
[2]) ||
185 (rdbuf
[2] != es
) || (memcmp(data
, &rdbuf
[3], len
) != 0))
188 /* Copy the scratchpad to EEPROM */
189 if (w1_reset_select_slave(sl
))
192 wrbuf
[0] = W1_F23_COPY_SCRATCH
;
194 w1_write_block(sl
->master
, wrbuf
, 4);
196 /* Sleep for 5 ms to wait for the write to complete */
199 /* Reset the bus to wake up the EEPROM (this may not be needed) */
200 w1_reset_bus(sl
->master
);
205 static ssize_t
w1_f23_write_bin(struct kobject
*kobj
, char *buf
, loff_t off
,
208 struct w1_slave
*sl
= kobj_to_w1_slave(kobj
);
211 if ((count
= w1_f23_fix_count(off
, count
, W1_EEPROM_SIZE
)) == 0)
214 #ifdef CONFIG_W1_F23_CRC
215 /* can only write full blocks in cached mode */
216 if ((off
& W1_PAGE_MASK
) || (count
& W1_PAGE_MASK
)) {
217 dev_err(&sl
->dev
, "invalid offset/count off=%d cnt=%d\n",
222 /* make sure the block CRCs are valid */
223 for (idx
= 0; idx
< count
; idx
+= W1_PAGE_SIZE
) {
224 if (crc16(CRC16_INIT
, &buf
[idx
], W1_PAGE_SIZE
) != CRC16_VALID
) {
225 dev_err(&sl
->dev
, "bad CRC at offset %d\n", (int)off
);
229 #endif /* CONFIG_W1_F23_CRC */
231 atomic_inc(&sl
->refcnt
);
232 if (down_interruptible(&sl
->master
->mutex
)) {
237 /* Can only write data to one page at a time */
239 while (idx
< count
) {
241 len
= W1_PAGE_SIZE
- (addr
& W1_PAGE_MASK
);
242 if (len
> (count
- idx
))
245 if (w1_f23_write(sl
, addr
, len
, &buf
[idx
]) < 0) {
253 up(&sl
->master
->mutex
);
255 atomic_dec(&sl
->refcnt
);
260 static struct bin_attribute w1_f23_bin_attr
= {
263 .mode
= S_IRUGO
| S_IWUSR
,
264 .owner
= THIS_MODULE
,
266 .size
= W1_EEPROM_SIZE
,
267 .read
= w1_f23_read_bin
,
268 .write
= w1_f23_write_bin
,
271 static int w1_f23_add_slave(struct w1_slave
*sl
)
274 #ifdef CONFIG_W1_F23_CRC
275 struct w1_f23_data
*data
;
277 data
= kmalloc(sizeof(struct w1_f23_data
), GFP_KERNEL
);
280 memset(data
, 0, sizeof(struct w1_f23_data
));
281 sl
->family_data
= data
;
283 #endif /* CONFIG_W1_F23_CRC */
285 err
= sysfs_create_bin_file(&sl
->dev
.kobj
, &w1_f23_bin_attr
);
287 #ifdef CONFIG_W1_F23_CRC
290 #endif /* CONFIG_W1_F23_CRC */
295 static void w1_f23_remove_slave(struct w1_slave
*sl
)
297 #ifdef CONFIG_W1_F23_CRC
298 if (sl
->family_data
) {
299 kfree(sl
->family_data
);
300 sl
->family_data
= NULL
;
302 #endif /* CONFIG_W1_F23_CRC */
303 sysfs_remove_bin_file(&sl
->dev
.kobj
, &w1_f23_bin_attr
);
306 static struct w1_family_ops w1_f23_fops
= {
307 .add_slave
= w1_f23_add_slave
,
308 .remove_slave
= w1_f23_remove_slave
,
311 static struct w1_family w1_family_23
= {
312 .fid
= W1_EEPROM_DS2433
,
313 .fops
= &w1_f23_fops
,
316 static int __init
w1_f23_init(void)
318 return w1_register_family(&w1_family_23
);
321 static void __exit
w1_f23_fini(void)
323 w1_unregister_family(&w1_family_23
);
326 module_init(w1_f23_init
);
327 module_exit(w1_f23_fini
);