2 * w1_ds28e04.c - w1 family 1C (DS28E04) driver
4 * Copyright (c) 2012 Markus Franke <franke.m@sebakmt.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 #include <linux/slab.h>
17 #include <linux/crc16.h>
18 #include <linux/uaccess.h>
21 #define CRC16_VALID 0xb001
24 #include "../w1_int.h"
25 #include "../w1_family.h"
27 MODULE_LICENSE("GPL");
28 MODULE_AUTHOR("Markus Franke <franke.m@sebakmt.com>, <franm@hrz.tu-chemnitz.de>");
29 MODULE_DESCRIPTION("w1 family 1C driver for DS28E04, 4kb EEPROM and PIO");
31 /* Allow the strong pullup to be disabled, but default to enabled.
32 * If it was disabled a parasite powered device might not get the required
33 * current to copy the data from the scratchpad to EEPROM. If it is enabled parasite powered
34 * devices have a better chance of getting the current required.
36 static int w1_strong_pullup = 1;
37 module_param_named(strong_pullup, w1_strong_pullup, int, 0);
39 /* enable/disable CRC checking on DS28E04-100 memory accesses */
40 static char w1_enable_crccheck = 1;
42 #define W1_EEPROM_SIZE 512
43 #define W1_PAGE_COUNT 16
44 #define W1_PAGE_SIZE 32
45 #define W1_PAGE_BITS 5
46 #define W1_PAGE_MASK 0x1F
48 #define W1_F1C_READ_EEPROM 0xF0
49 #define W1_F1C_WRITE_SCRATCH 0x0F
50 #define W1_F1C_READ_SCRATCH 0xAA
51 #define W1_F1C_COPY_SCRATCH 0x55
52 #define W1_F1C_ACCESS_WRITE 0x5A
54 #define W1_1C_REG_LOGIC_STATE 0x220
57 u8 memory[W1_EEPROM_SIZE];
62 * Check the file size bounds and adjusts count as needed.
63 * This would not be needed if the file size didn't reset to 0 after a write.
65 static inline size_t w1_f1C_fix_count(loff_t off, size_t count, size_t size)
70 if ((off + count) > size)
76 static int w1_f1C_refresh_block(struct w1_slave *sl, struct w1_f1C_data *data,
80 int off = block * W1_PAGE_SIZE;
82 if (data->validcrc & (1 << block))
85 if (w1_reset_select_slave(sl)) {
90 wrbuf[0] = W1_F1C_READ_EEPROM;
91 wrbuf[1] = off & 0xff;
93 w1_write_block(sl->master, wrbuf, 3);
94 w1_read_block(sl->master, &data->memory[off], W1_PAGE_SIZE);
96 /* cache the block if the CRC is valid */
97 if (crc16(CRC16_INIT, &data->memory[off], W1_PAGE_SIZE) == CRC16_VALID)
98 data->validcrc |= (1 << block);
103 static int w1_f1C_read(struct w1_slave *sl, int addr, int len, char *data)
107 /* read directly from the EEPROM */
108 if (w1_reset_select_slave(sl))
111 wrbuf[0] = W1_F1C_READ_EEPROM;
112 wrbuf[1] = addr & 0xff;
113 wrbuf[2] = addr >> 8;
115 w1_write_block(sl->master, wrbuf, sizeof(wrbuf));
116 return w1_read_block(sl->master, data, len);
119 static ssize_t w1_f1C_read_bin(struct file *filp, struct kobject *kobj,
120 struct bin_attribute *bin_attr,
121 char *buf, loff_t off, size_t count)
123 struct w1_slave *sl = kobj_to_w1_slave(kobj);
124 struct w1_f1C_data *data = sl->family_data;
125 int i, min_page, max_page;
127 if ((count = w1_f1C_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
130 mutex_lock(&sl->master->mutex);
132 if(w1_enable_crccheck) {
133 min_page = (off >> W1_PAGE_BITS);
134 max_page = (off + count - 1) >> W1_PAGE_BITS;
135 for (i = min_page; i <= max_page; i++) {
136 if (w1_f1C_refresh_block(sl, data, i)) {
141 memcpy(buf, &data->memory[off], count);
144 count = w1_f1C_read(sl, off, count, buf);
148 mutex_unlock(&sl->master->mutex);
154 * Writes to the scratchpad and reads it back for verification.
155 * Then copies the scratchpad to EEPROM.
156 * The data must be on one page.
157 * The master must be locked.
159 * @param sl The slave structure
160 * @param addr Address for the write
161 * @param len length must be <= (W1_PAGE_SIZE - (addr & W1_PAGE_MASK))
162 * @param data The data to write
163 * @return 0=Success -1=failure
165 static int w1_f1C_write(struct w1_slave *sl, int addr, int len, const u8 *data)
168 u8 rdbuf[W1_PAGE_SIZE + 3];
169 u8 es = (addr + len - 1) & 0x1f;
170 unsigned int tm = 10;
172 struct w1_f1C_data *f1C = sl->family_data;
174 /* Write the data to the scratchpad */
175 if (w1_reset_select_slave(sl))
178 wrbuf[0] = W1_F1C_WRITE_SCRATCH;
179 wrbuf[1] = addr & 0xff;
180 wrbuf[2] = addr >> 8;
182 w1_write_block(sl->master, wrbuf, 3);
183 w1_write_block(sl->master, data, len);
185 /* Read the scratchpad and verify */
186 if (w1_reset_select_slave(sl))
189 w1_write_8(sl->master, W1_F1C_READ_SCRATCH);
190 w1_read_block(sl->master, rdbuf, len + 3);
192 /* Compare what was read against the data written */
193 if ((rdbuf[0] != wrbuf[1]) || (rdbuf[1] != wrbuf[2]) ||
194 (rdbuf[2] != es) || (memcmp(data, &rdbuf[3], len) != 0))
197 /* Copy the scratchpad to EEPROM */
198 if (w1_reset_select_slave(sl))
201 wrbuf[0] = W1_F1C_COPY_SCRATCH;
204 for(i = 0; i < sizeof(wrbuf); ++i) {
205 /* issue 10ms strong pullup (or delay) on the last byte for writing the data from the scratchpad to EEPROM */
206 if(w1_strong_pullup && i == sizeof(wrbuf)-1)
207 w1_next_pullup(sl->master, tm);
209 w1_write_8(sl->master, wrbuf[i]);
212 if(!w1_strong_pullup)
215 if(w1_enable_crccheck) {
216 /* invalidate cached data */
217 f1C->validcrc &= ~(1 << (addr >> W1_PAGE_BITS));
220 /* Reset the bus to wake up the EEPROM (this may not be needed) */
221 w1_reset_bus(sl->master);
226 static ssize_t w1_f1C_write_bin(struct file *filp, struct kobject *kobj,
227 struct bin_attribute *bin_attr,
228 char *buf, loff_t off, size_t count)
231 struct w1_slave *sl = kobj_to_w1_slave(kobj);
234 if ((count = w1_f1C_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
237 if(w1_enable_crccheck) {
238 /* can only write full blocks in cached mode */
239 if ((off & W1_PAGE_MASK) || (count & W1_PAGE_MASK)) {
240 dev_err(&sl->dev, "invalid offset/count off=%d cnt=%zd\n",
245 /* make sure the block CRCs are valid */
246 for (idx = 0; idx < count; idx += W1_PAGE_SIZE) {
247 if (crc16(CRC16_INIT, &buf[idx], W1_PAGE_SIZE) != CRC16_VALID) {
248 dev_err(&sl->dev, "bad CRC at offset %d\n", (int)off);
254 mutex_lock(&sl->master->mutex);
256 /* Can only write data to one page at a time */
258 while (idx < count) {
260 len = W1_PAGE_SIZE - (addr & W1_PAGE_MASK);
261 if (len > (count - idx))
264 if (w1_f1C_write(sl, addr, len, &buf[idx]) < 0) {
272 mutex_unlock(&sl->master->mutex);
277 static ssize_t w1_f1C_read_pio(struct file *filp, struct kobject *kobj,
278 struct bin_attribute *bin_attr,
279 char *buf, loff_t off, size_t count)
282 struct w1_slave *sl = kobj_to_w1_slave(kobj);
285 /* check arguments */
286 if(off != 0 || count != 1 || buf == NULL)
289 mutex_lock(&sl->master->mutex);
290 ret = w1_f1C_read(sl, W1_1C_REG_LOGIC_STATE, count, buf);
291 mutex_unlock(&sl->master->mutex);
296 static ssize_t w1_f1C_write_pio(struct file *filp, struct kobject *kobj,
297 struct bin_attribute *bin_attr,
298 char *buf, loff_t off, size_t count)
301 struct w1_slave *sl = kobj_to_w1_slave(kobj);
305 /* check arguments */
306 if(off != 0 || count != 1 || buf == NULL)
309 mutex_lock(&sl->master->mutex);
311 /* Write the PIO data */
312 if (w1_reset_select_slave(sl))
315 /* set bit 7..2 to value '1' */
318 wrbuf[0] = W1_F1C_ACCESS_WRITE;
321 w1_write_block(sl->master, wrbuf, 3);
323 w1_read_block(sl->master, &ack, sizeof(ack));
325 mutex_unlock(&sl->master->mutex);
327 /* check for acknowledgement */
328 if(ack != 0xAA) return -EIO;
333 static ssize_t w1_f1C_show_crccheck(struct device *dev, struct device_attribute *attr,
336 if(put_user(w1_enable_crccheck + 0x30, buf))
339 return sizeof(w1_enable_crccheck);
342 static ssize_t w1_f1C_store_crccheck(struct device *dev, struct device_attribute *attr,
343 const char *buf, size_t count)
347 if(count != 1 || !buf) return -EINVAL;
349 if(get_user(val, buf))
352 /* convert to decimal */
354 if(val != 0 && val != 1) return -EINVAL;
356 /* set the new value */
357 w1_enable_crccheck = val;
359 return sizeof(w1_enable_crccheck);
362 #define NB_SYSFS_BIN_FILES 2
363 static struct bin_attribute w1_f1C_bin_attr[NB_SYSFS_BIN_FILES] = {
367 .mode = S_IRUGO | S_IWUSR,
369 .size = W1_EEPROM_SIZE,
370 .read = w1_f1C_read_bin,
371 .write = w1_f1C_write_bin,
376 .mode = S_IRUGO | S_IWUSR,
379 .read = w1_f1C_read_pio,
380 .write = w1_f1C_write_pio,
384 static DEVICE_ATTR(crccheck, S_IWUSR | S_IRUGO, w1_f1C_show_crccheck, w1_f1C_store_crccheck);
386 static int w1_f1C_add_slave(struct w1_slave *sl)
390 struct w1_f1C_data *data = NULL;
392 if(w1_enable_crccheck) {
393 data = kzalloc(sizeof(struct w1_f1C_data), GFP_KERNEL);
396 sl->family_data = data;
399 /* create binary sysfs attributes */
400 for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i)
401 err = sysfs_create_bin_file(&sl->dev.kobj, &(w1_f1C_bin_attr[i]));
406 /* create device attributes */
407 err = device_create_file(&sl->dev, &dev_attr_crccheck);
410 /* remove binary sysfs attributes */
411 for (i = 0; i < NB_SYSFS_BIN_FILES; ++i)
412 sysfs_remove_bin_file(&sl->dev.kobj, &(w1_f1C_bin_attr[i]));
417 if(w1_enable_crccheck)
424 static void w1_f1C_remove_slave(struct w1_slave *sl)
428 if(w1_enable_crccheck) {
429 kfree(sl->family_data);
430 sl->family_data = NULL;
433 /* remove device attributes */
434 device_remove_file(&sl->dev, &dev_attr_crccheck);
436 /* remove binary sysfs attributes */
437 for (i = 0; i < NB_SYSFS_BIN_FILES; ++i)
438 sysfs_remove_bin_file(&sl->dev.kobj, &(w1_f1C_bin_attr[i]));
441 static struct w1_family_ops w1_f1C_fops = {
442 .add_slave = w1_f1C_add_slave,
443 .remove_slave = w1_f1C_remove_slave,
446 static struct w1_family w1_family_1C = {
447 .fid = W1_FAMILY_DS28E04,
448 .fops = &w1_f1C_fops,
451 static int __init w1_f1C_init(void)
453 return w1_register_family(&w1_family_1C);
456 static void __exit w1_f1C_fini(void)
458 w1_unregister_family(&w1_family_1C);
461 module_init(w1_f1C_init);
462 module_exit(w1_f1C_fini);