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");
30 MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS28E04));
32 /* Allow the strong pullup to be disabled, but default to enabled.
33 * If it was disabled a parasite powered device might not get the required
34 * current to copy the data from the scratchpad to EEPROM. If it is enabled
35 * parasite powered devices have a better chance of getting the current
38 static int w1_strong_pullup = 1;
39 module_param_named(strong_pullup, w1_strong_pullup, int, 0);
41 /* enable/disable CRC checking on DS28E04-100 memory accesses */
42 static char w1_enable_crccheck = 1;
44 #define W1_EEPROM_SIZE 512
45 #define W1_PAGE_COUNT 16
46 #define W1_PAGE_SIZE 32
47 #define W1_PAGE_BITS 5
48 #define W1_PAGE_MASK 0x1F
50 #define W1_F1C_READ_EEPROM 0xF0
51 #define W1_F1C_WRITE_SCRATCH 0x0F
52 #define W1_F1C_READ_SCRATCH 0xAA
53 #define W1_F1C_COPY_SCRATCH 0x55
54 #define W1_F1C_ACCESS_WRITE 0x5A
56 #define W1_1C_REG_LOGIC_STATE 0x220
59 u8 memory[W1_EEPROM_SIZE];
64 * Check the file size bounds and adjusts count as needed.
65 * This would not be needed if the file size didn't reset to 0 after a write.
67 static inline size_t w1_f1C_fix_count(loff_t off, size_t count, size_t size)
72 if ((off + count) > size)
78 static int w1_f1C_refresh_block(struct w1_slave *sl, struct w1_f1C_data *data,
82 int off = block * W1_PAGE_SIZE;
84 if (data->validcrc & (1 << block))
87 if (w1_reset_select_slave(sl)) {
92 wrbuf[0] = W1_F1C_READ_EEPROM;
93 wrbuf[1] = off & 0xff;
95 w1_write_block(sl->master, wrbuf, 3);
96 w1_read_block(sl->master, &data->memory[off], W1_PAGE_SIZE);
98 /* cache the block if the CRC is valid */
99 if (crc16(CRC16_INIT, &data->memory[off], W1_PAGE_SIZE) == CRC16_VALID)
100 data->validcrc |= (1 << block);
105 static int w1_f1C_read(struct w1_slave *sl, int addr, int len, char *data)
109 /* read directly from the EEPROM */
110 if (w1_reset_select_slave(sl))
113 wrbuf[0] = W1_F1C_READ_EEPROM;
114 wrbuf[1] = addr & 0xff;
115 wrbuf[2] = addr >> 8;
117 w1_write_block(sl->master, wrbuf, sizeof(wrbuf));
118 return w1_read_block(sl->master, data, len);
121 static ssize_t w1_f1C_read_bin(struct file *filp, struct kobject *kobj,
122 struct bin_attribute *bin_attr,
123 char *buf, loff_t off, size_t count)
125 struct w1_slave *sl = kobj_to_w1_slave(kobj);
126 struct w1_f1C_data *data = sl->family_data;
127 int i, min_page, max_page;
129 count = w1_f1C_fix_count(off, count, W1_EEPROM_SIZE);
133 mutex_lock(&sl->master->mutex);
135 if (w1_enable_crccheck) {
136 min_page = (off >> W1_PAGE_BITS);
137 max_page = (off + count - 1) >> W1_PAGE_BITS;
138 for (i = min_page; i <= max_page; i++) {
139 if (w1_f1C_refresh_block(sl, data, i)) {
144 memcpy(buf, &data->memory[off], count);
146 count = w1_f1C_read(sl, off, count, buf);
150 mutex_unlock(&sl->master->mutex);
156 * Writes to the scratchpad and reads it back for verification.
157 * Then copies the scratchpad to EEPROM.
158 * The data must be on one page.
159 * The master must be locked.
161 * @param sl The slave structure
162 * @param addr Address for the write
163 * @param len length must be <= (W1_PAGE_SIZE - (addr & W1_PAGE_MASK))
164 * @param data The data to write
165 * @return 0=Success -1=failure
167 static int w1_f1C_write(struct w1_slave *sl, int addr, int len, const u8 *data)
170 u8 rdbuf[W1_PAGE_SIZE + 3];
171 u8 es = (addr + len - 1) & 0x1f;
172 unsigned int tm = 10;
174 struct w1_f1C_data *f1C = sl->family_data;
176 /* Write the data to the scratchpad */
177 if (w1_reset_select_slave(sl))
180 wrbuf[0] = W1_F1C_WRITE_SCRATCH;
181 wrbuf[1] = addr & 0xff;
182 wrbuf[2] = addr >> 8;
184 w1_write_block(sl->master, wrbuf, 3);
185 w1_write_block(sl->master, data, len);
187 /* Read the scratchpad and verify */
188 if (w1_reset_select_slave(sl))
191 w1_write_8(sl->master, W1_F1C_READ_SCRATCH);
192 w1_read_block(sl->master, rdbuf, len + 3);
194 /* Compare what was read against the data written */
195 if ((rdbuf[0] != wrbuf[1]) || (rdbuf[1] != wrbuf[2]) ||
196 (rdbuf[2] != es) || (memcmp(data, &rdbuf[3], len) != 0))
199 /* Copy the scratchpad to EEPROM */
200 if (w1_reset_select_slave(sl))
203 wrbuf[0] = W1_F1C_COPY_SCRATCH;
206 for (i = 0; i < sizeof(wrbuf); ++i) {
207 /* issue 10ms strong pullup (or delay) on the last byte
208 for writing the data from the scratchpad to EEPROM */
209 if (w1_strong_pullup && i == sizeof(wrbuf)-1)
210 w1_next_pullup(sl->master, tm);
212 w1_write_8(sl->master, wrbuf[i]);
215 if (!w1_strong_pullup)
218 if (w1_enable_crccheck) {
219 /* invalidate cached data */
220 f1C->validcrc &= ~(1 << (addr >> W1_PAGE_BITS));
223 /* Reset the bus to wake up the EEPROM (this may not be needed) */
224 w1_reset_bus(sl->master);
229 static ssize_t w1_f1C_write_bin(struct file *filp, struct kobject *kobj,
230 struct bin_attribute *bin_attr,
231 char *buf, loff_t off, size_t count)
234 struct w1_slave *sl = kobj_to_w1_slave(kobj);
237 count = w1_f1C_fix_count(off, count, W1_EEPROM_SIZE);
241 if (w1_enable_crccheck) {
242 /* can only write full blocks in cached mode */
243 if ((off & W1_PAGE_MASK) || (count & W1_PAGE_MASK)) {
244 dev_err(&sl->dev, "invalid offset/count off=%d cnt=%zd\n",
249 /* make sure the block CRCs are valid */
250 for (idx = 0; idx < count; idx += W1_PAGE_SIZE) {
251 if (crc16(CRC16_INIT, &buf[idx], W1_PAGE_SIZE)
253 dev_err(&sl->dev, "bad CRC at offset %d\n",
260 mutex_lock(&sl->master->mutex);
262 /* Can only write data to one page at a time */
264 while (idx < count) {
266 len = W1_PAGE_SIZE - (addr & W1_PAGE_MASK);
267 if (len > (count - idx))
270 if (w1_f1C_write(sl, addr, len, &buf[idx]) < 0) {
278 mutex_unlock(&sl->master->mutex);
283 static ssize_t w1_f1C_read_pio(struct file *filp, struct kobject *kobj,
284 struct bin_attribute *bin_attr,
285 char *buf, loff_t off, size_t count)
288 struct w1_slave *sl = kobj_to_w1_slave(kobj);
291 /* check arguments */
292 if (off != 0 || count != 1 || buf == NULL)
295 mutex_lock(&sl->master->mutex);
296 ret = w1_f1C_read(sl, W1_1C_REG_LOGIC_STATE, count, buf);
297 mutex_unlock(&sl->master->mutex);
302 static ssize_t w1_f1C_write_pio(struct file *filp, struct kobject *kobj,
303 struct bin_attribute *bin_attr,
304 char *buf, loff_t off, size_t count)
307 struct w1_slave *sl = kobj_to_w1_slave(kobj);
311 /* check arguments */
312 if (off != 0 || count != 1 || buf == NULL)
315 mutex_lock(&sl->master->mutex);
317 /* Write the PIO data */
318 if (w1_reset_select_slave(sl)) {
319 mutex_unlock(&sl->master->mutex);
323 /* set bit 7..2 to value '1' */
326 wrbuf[0] = W1_F1C_ACCESS_WRITE;
329 w1_write_block(sl->master, wrbuf, 3);
331 w1_read_block(sl->master, &ack, sizeof(ack));
333 mutex_unlock(&sl->master->mutex);
335 /* check for acknowledgement */
342 static ssize_t w1_f1C_show_crccheck(struct device *dev,
343 struct device_attribute *attr, char *buf)
345 if (put_user(w1_enable_crccheck + 0x30, buf))
348 return sizeof(w1_enable_crccheck);
351 static ssize_t w1_f1C_store_crccheck(struct device *dev,
352 struct device_attribute *attr,
353 const char *buf, size_t count)
357 if (count != 1 || !buf)
360 if (get_user(val, buf))
363 /* convert to decimal */
365 if (val != 0 && val != 1)
368 /* set the new value */
369 w1_enable_crccheck = val;
371 return sizeof(w1_enable_crccheck);
374 #define NB_SYSFS_BIN_FILES 2
375 static struct bin_attribute w1_f1C_bin_attr[NB_SYSFS_BIN_FILES] = {
379 .mode = S_IRUGO | S_IWUSR,
381 .size = W1_EEPROM_SIZE,
382 .read = w1_f1C_read_bin,
383 .write = w1_f1C_write_bin,
388 .mode = S_IRUGO | S_IWUSR,
391 .read = w1_f1C_read_pio,
392 .write = w1_f1C_write_pio,
396 static DEVICE_ATTR(crccheck, S_IWUSR | S_IRUGO,
397 w1_f1C_show_crccheck, w1_f1C_store_crccheck);
399 static int w1_f1C_add_slave(struct w1_slave *sl)
403 struct w1_f1C_data *data = NULL;
405 if (w1_enable_crccheck) {
406 data = kzalloc(sizeof(struct w1_f1C_data), GFP_KERNEL);
409 sl->family_data = data;
412 /* create binary sysfs attributes */
413 for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i)
414 err = sysfs_create_bin_file(
415 &sl->dev.kobj, &(w1_f1C_bin_attr[i]));
418 /* create device attributes */
419 err = device_create_file(&sl->dev, &dev_attr_crccheck);
423 /* remove binary sysfs attributes */
424 for (i = 0; i < NB_SYSFS_BIN_FILES; ++i)
425 sysfs_remove_bin_file(
426 &sl->dev.kobj, &(w1_f1C_bin_attr[i]));
434 static void w1_f1C_remove_slave(struct w1_slave *sl)
438 kfree(sl->family_data);
439 sl->family_data = NULL;
441 /* remove device attributes */
442 device_remove_file(&sl->dev, &dev_attr_crccheck);
444 /* remove binary sysfs attributes */
445 for (i = 0; i < NB_SYSFS_BIN_FILES; ++i)
446 sysfs_remove_bin_file(&sl->dev.kobj, &(w1_f1C_bin_attr[i]));
449 static struct w1_family_ops w1_f1C_fops = {
450 .add_slave = w1_f1C_add_slave,
451 .remove_slave = w1_f1C_remove_slave,
454 static struct w1_family w1_family_1C = {
455 .fid = W1_FAMILY_DS28E04,
456 .fops = &w1_f1C_fops,
459 static int __init w1_f1C_init(void)
461 return w1_register_family(&w1_family_1C);
464 static void __exit w1_f1C_fini(void)
466 w1_unregister_family(&w1_family_1C);
469 module_init(w1_f1C_init);
470 module_exit(w1_f1C_fini);