2 * w1_ds2408.c - w1 family 29 (DS2408) driver
4 * Copyright (c) 2010 Jean-Francois Dagenais <dagenaisj@sonatest.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>
19 #include "../w1_int.h"
20 #include "../w1_family.h"
22 MODULE_LICENSE("GPL");
23 MODULE_AUTHOR("Jean-Francois Dagenais <dagenaisj@sonatest.com>");
24 MODULE_DESCRIPTION("w1 family 29 driver for DS2408 8 Pin IO");
27 #define W1_F29_RETRIES 3
29 #define W1_F29_REG_LOGIG_STATE 0x88 /* R */
30 #define W1_F29_REG_OUTPUT_LATCH_STATE 0x89 /* R */
31 #define W1_F29_REG_ACTIVITY_LATCH_STATE 0x8A /* R */
32 #define W1_F29_REG_COND_SEARCH_SELECT_MASK 0x8B /* RW */
33 #define W1_F29_REG_COND_SEARCH_POL_SELECT 0x8C /* RW */
34 #define W1_F29_REG_CONTROL_AND_STATUS 0x8D /* RW */
36 #define W1_F29_FUNC_READ_PIO_REGS 0xF0
37 #define W1_F29_FUNC_CHANN_ACCESS_READ 0xF5
38 #define W1_F29_FUNC_CHANN_ACCESS_WRITE 0x5A
39 /* also used to write the control/status reg (0x8D): */
40 #define W1_F29_FUNC_WRITE_COND_SEARCH_REG 0xCC
41 #define W1_F29_FUNC_RESET_ACTIVITY_LATCHES 0xC3
43 #define W1_F29_SUCCESS_CONFIRM_BYTE 0xAA
45 static int _read_reg(struct w1_slave *sl, u8 address, unsigned char* buf)
49 "Reading with slave: %p, reg addr: %0#4x, buff addr: %p",
50 sl, (unsigned int)address, buf);
55 mutex_lock(&sl->master->bus_mutex);
56 dev_dbg(&sl->dev, "mutex locked");
58 if (w1_reset_select_slave(sl)) {
59 mutex_unlock(&sl->master->bus_mutex);
63 wrbuf[0] = W1_F29_FUNC_READ_PIO_REGS;
66 w1_write_block(sl->master, wrbuf, 3);
67 *buf = w1_read_8(sl->master);
69 mutex_unlock(&sl->master->bus_mutex);
70 dev_dbg(&sl->dev, "mutex unlocked");
74 static ssize_t w1_f29_read_state(
75 struct file *filp, struct kobject *kobj,
76 struct bin_attribute *bin_attr,
77 char *buf, loff_t off, size_t count)
79 dev_dbg(&kobj_to_w1_slave(kobj)->dev,
80 "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p",
81 bin_attr->attr.name, kobj, (unsigned int)off, count, buf);
82 if (count != 1 || off != 0)
84 return _read_reg(kobj_to_w1_slave(kobj), W1_F29_REG_LOGIG_STATE, buf);
87 static ssize_t w1_f29_read_output(
88 struct file *filp, struct kobject *kobj,
89 struct bin_attribute *bin_attr,
90 char *buf, loff_t off, size_t count)
92 dev_dbg(&kobj_to_w1_slave(kobj)->dev,
93 "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p",
94 bin_attr->attr.name, kobj, (unsigned int)off, count, buf);
95 if (count != 1 || off != 0)
97 return _read_reg(kobj_to_w1_slave(kobj),
98 W1_F29_REG_OUTPUT_LATCH_STATE, buf);
101 static ssize_t w1_f29_read_activity(
102 struct file *filp, struct kobject *kobj,
103 struct bin_attribute *bin_attr,
104 char *buf, loff_t off, size_t count)
106 dev_dbg(&kobj_to_w1_slave(kobj)->dev,
107 "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p",
108 bin_attr->attr.name, kobj, (unsigned int)off, count, buf);
109 if (count != 1 || off != 0)
111 return _read_reg(kobj_to_w1_slave(kobj),
112 W1_F29_REG_ACTIVITY_LATCH_STATE, buf);
115 static ssize_t w1_f29_read_cond_search_mask(
116 struct file *filp, struct kobject *kobj,
117 struct bin_attribute *bin_attr,
118 char *buf, loff_t off, size_t count)
120 dev_dbg(&kobj_to_w1_slave(kobj)->dev,
121 "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p",
122 bin_attr->attr.name, kobj, (unsigned int)off, count, buf);
123 if (count != 1 || off != 0)
125 return _read_reg(kobj_to_w1_slave(kobj),
126 W1_F29_REG_COND_SEARCH_SELECT_MASK, buf);
129 static ssize_t w1_f29_read_cond_search_polarity(
130 struct file *filp, struct kobject *kobj,
131 struct bin_attribute *bin_attr,
132 char *buf, loff_t off, size_t count)
134 if (count != 1 || off != 0)
136 return _read_reg(kobj_to_w1_slave(kobj),
137 W1_F29_REG_COND_SEARCH_POL_SELECT, buf);
140 static ssize_t w1_f29_read_status_control(
141 struct file *filp, struct kobject *kobj,
142 struct bin_attribute *bin_attr,
143 char *buf, loff_t off, size_t count)
145 if (count != 1 || off != 0)
147 return _read_reg(kobj_to_w1_slave(kobj),
148 W1_F29_REG_CONTROL_AND_STATUS, buf);
154 static ssize_t w1_f29_write_output(
155 struct file *filp, struct kobject *kobj,
156 struct bin_attribute *bin_attr,
157 char *buf, loff_t off, size_t count)
159 struct w1_slave *sl = kobj_to_w1_slave(kobj);
162 unsigned int retries = W1_F29_RETRIES;
164 if (count != 1 || off != 0)
167 dev_dbg(&sl->dev, "locking mutex for write_output");
168 mutex_lock(&sl->master->bus_mutex);
169 dev_dbg(&sl->dev, "mutex locked");
171 if (w1_reset_select_slave(sl))
175 w1_buf[0] = W1_F29_FUNC_CHANN_ACCESS_WRITE;
178 w1_write_block(sl->master, w1_buf, 3);
180 readBack = w1_read_8(sl->master);
182 if (readBack != W1_F29_SUCCESS_CONFIRM_BYTE) {
183 if (w1_reset_resume_command(sl->master))
185 /* try again, the slave is ready for a command */
189 #ifdef CONFIG_W1_SLAVE_DS2408_READBACK
190 /* here the master could read another byte which
191 would be the PIO reg (the actual pin logic state)
192 since in this driver we don't know which pins are
193 in and outs, there's no value to read the state and
194 compare. with (*buf) so end this command abruptly: */
195 if (w1_reset_resume_command(sl->master))
198 /* go read back the output latches */
199 /* (the direct effect of the write above) */
200 w1_buf[0] = W1_F29_FUNC_READ_PIO_REGS;
201 w1_buf[1] = W1_F29_REG_OUTPUT_LATCH_STATE;
203 w1_write_block(sl->master, w1_buf, 3);
204 /* read the result of the READ_PIO_REGS command */
205 if (w1_read_8(sl->master) == *buf)
209 mutex_unlock(&sl->master->bus_mutex);
211 "mutex unlocked, retries:%d", retries);
216 mutex_unlock(&sl->master->bus_mutex);
217 dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries);
224 * Writing to the activity file resets the activity latches.
226 static ssize_t w1_f29_write_activity(
227 struct file *filp, struct kobject *kobj,
228 struct bin_attribute *bin_attr,
229 char *buf, loff_t off, size_t count)
231 struct w1_slave *sl = kobj_to_w1_slave(kobj);
232 unsigned int retries = W1_F29_RETRIES;
234 if (count != 1 || off != 0)
237 mutex_lock(&sl->master->bus_mutex);
239 if (w1_reset_select_slave(sl))
243 w1_write_8(sl->master, W1_F29_FUNC_RESET_ACTIVITY_LATCHES);
244 if (w1_read_8(sl->master) == W1_F29_SUCCESS_CONFIRM_BYTE) {
245 mutex_unlock(&sl->master->bus_mutex);
248 if (w1_reset_resume_command(sl->master))
253 mutex_unlock(&sl->master->bus_mutex);
257 static ssize_t w1_f29_write_status_control(
259 struct kobject *kobj,
260 struct bin_attribute *bin_attr,
265 struct w1_slave *sl = kobj_to_w1_slave(kobj);
267 unsigned int retries = W1_F29_RETRIES;
269 if (count != 1 || off != 0)
272 mutex_lock(&sl->master->bus_mutex);
274 if (w1_reset_select_slave(sl))
278 w1_buf[0] = W1_F29_FUNC_WRITE_COND_SEARCH_REG;
279 w1_buf[1] = W1_F29_REG_CONTROL_AND_STATUS;
283 w1_write_block(sl->master, w1_buf, 4);
284 if (w1_reset_resume_command(sl->master))
287 w1_buf[0] = W1_F29_FUNC_READ_PIO_REGS;
288 w1_buf[1] = W1_F29_REG_CONTROL_AND_STATUS;
291 w1_write_block(sl->master, w1_buf, 3);
292 if (w1_read_8(sl->master) == *buf) {
294 mutex_unlock(&sl->master->bus_mutex);
299 mutex_unlock(&sl->master->bus_mutex);
306 static struct bin_attribute w1_f29_sysfs_bin_files[] = {
313 .read = w1_f29_read_state,
318 .mode = S_IRUGO | S_IWUSR | S_IWGRP,
321 .read = w1_f29_read_output,
322 .write = w1_f29_write_output,
330 .read = w1_f29_read_activity,
331 .write = w1_f29_write_activity,
335 .name = "cond_search_mask",
339 .read = w1_f29_read_cond_search_mask,
343 .name = "cond_search_polarity",
347 .read = w1_f29_read_cond_search_polarity,
351 .name = "status_control",
352 .mode = S_IRUGO | S_IWUSR | S_IWGRP,
355 .read = w1_f29_read_status_control,
356 .write = w1_f29_write_status_control,
360 static int w1_f29_add_slave(struct w1_slave *sl)
365 for (i = 0; i < ARRAY_SIZE(w1_f29_sysfs_bin_files) && !err; ++i)
366 err = sysfs_create_bin_file(
368 &(w1_f29_sysfs_bin_files[i]));
371 sysfs_remove_bin_file(&sl->dev.kobj,
372 &(w1_f29_sysfs_bin_files[i]));
376 static void w1_f29_remove_slave(struct w1_slave *sl)
379 for (i = ARRAY_SIZE(w1_f29_sysfs_bin_files) - 1; i >= 0; --i)
380 sysfs_remove_bin_file(&sl->dev.kobj,
381 &(w1_f29_sysfs_bin_files[i]));
384 static struct w1_family_ops w1_f29_fops = {
385 .add_slave = w1_f29_add_slave,
386 .remove_slave = w1_f29_remove_slave,
389 static struct w1_family w1_family_29 = {
390 .fid = W1_FAMILY_DS2408,
391 .fops = &w1_f29_fops,
394 static int __init w1_f29_init(void)
396 return w1_register_family(&w1_family_29);
399 static void __exit w1_f29_exit(void)
401 w1_unregister_family(&w1_family_29);
404 module_init(w1_f29_init);
405 module_exit(w1_f29_exit);