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Evgeniy Polyakov80895392005-08-11 17:27:50 +04001/*
2 * w1_ds2433.c - w1 family 23 (DS2433) driver
3 *
4 * Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com>
5 *
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +04006 * This source code is licensed under the GNU General Public License,
7 * Version 2. See the file COPYING for more details.
Evgeniy Polyakov80895392005-08-11 17:27:50 +04008 */
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>
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -080016#ifdef CONFIG_W1_SLAVE_DS2433_CRC
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +040017#include <linux/crc16.h>
Evgeniy Polyakovf24ec7f2005-09-12 17:12:43 +040018
19#define CRC16_INIT 0
20#define CRC16_VALID 0xb001
21
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +040022#endif
Evgeniy Polyakov80895392005-08-11 17:27:50 +040023
Evgeniy Polyakovbd529cf2005-12-06 13:38:28 +030024#include "../w1.h"
Evgeniy Polyakovbd529cf2005-12-06 13:38:28 +030025#include "../w1_int.h"
26#include "../w1_family.h"
Evgeniy Polyakov80895392005-08-11 17:27:50 +040027
28MODULE_LICENSE("GPL");
29MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
30MODULE_DESCRIPTION("w1 family 23 driver for DS2433, 4kb EEPROM");
31
32#define W1_EEPROM_SIZE 512
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +040033#define W1_PAGE_COUNT 16
Evgeniy Polyakov80895392005-08-11 17:27:50 +040034#define W1_PAGE_SIZE 32
35#define W1_PAGE_BITS 5
36#define W1_PAGE_MASK 0x1F
37
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +040038#define W1_F23_TIME 300
39
Evgeniy Polyakov80895392005-08-11 17:27:50 +040040#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
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +040045struct w1_f23_data {
46 u8 memory[W1_EEPROM_SIZE];
47 u32 validcrc;
48};
49
Evgeniy Polyakov80895392005-08-11 17:27:50 +040050/**
51 * Check the file size bounds and adjusts count as needed.
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +040052 * This would not be needed if the file size didn't reset to 0 after a write.
Evgeniy Polyakov80895392005-08-11 17:27:50 +040053 */
54static 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
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -080065#ifdef CONFIG_W1_SLAVE_DS2433_CRC
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +040066static 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}
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -080092#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +040093
Zhang Rui91a69022007-06-09 13:57:22 +080094static ssize_t w1_f23_read_bin(struct kobject *kobj,
95 struct bin_attribute *bin_attr,
96 char *buf, loff_t off, size_t count)
Evgeniy Polyakov80895392005-08-11 17:27:50 +040097{
98 struct w1_slave *sl = kobj_to_w1_slave(kobj);
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -080099#ifdef CONFIG_W1_SLAVE_DS2433_CRC
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400100 struct w1_f23_data *data = sl->family_data;
101 int i, min_page, max_page;
102#else
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400103 u8 wrbuf[3];
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400104#endif
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400105
106 if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
107 return 0;
108
Evgeniy Polyakovabd52a12006-04-03 12:04:27 +0400109 mutex_lock(&sl->master->mutex);
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400110
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -0800111#ifdef CONFIG_W1_SLAVE_DS2433_CRC
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400112
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
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -0800123#else /* CONFIG_W1_SLAVE_DS2433_CRC */
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400124
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400125 /* 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
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -0800137#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400138
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400139out_up:
Evgeniy Polyakovabd52a12006-04-03 12:04:27 +0400140 mutex_unlock(&sl->master->mutex);
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400141
142 return count;
143}
144
145/**
146 * Writes to the scratchpad and reads it back for verification.
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400147 * Then copies the scratchpad to EEPROM.
148 * The data must be on one page.
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400149 * 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 */
157static int w1_f23_write(struct w1_slave *sl, int addr, int len, const u8 *data)
158{
Ben Gardnerdca17142009-02-27 14:02:58 -0800159#ifdef CONFIG_W1_SLAVE_DS2433_CRC
160 struct w1_f23_data *f23 = sl->family_data;
161#endif
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400162 u8 wrbuf[4];
163 u8 rdbuf[W1_PAGE_SIZE + 3];
164 u8 es = (addr + len - 1) & 0x1f;
165
166 /* Write the data to the scratchpad */
167 if (w1_reset_select_slave(sl))
168 return -1;
169
170 wrbuf[0] = W1_F23_WRITE_SCRATCH;
171 wrbuf[1] = addr & 0xff;
172 wrbuf[2] = addr >> 8;
173
174 w1_write_block(sl->master, wrbuf, 3);
175 w1_write_block(sl->master, data, len);
176
177 /* Read the scratchpad and verify */
178 if (w1_reset_select_slave(sl))
179 return -1;
180
181 w1_write_8(sl->master, W1_F23_READ_SCRATCH);
182 w1_read_block(sl->master, rdbuf, len + 3);
183
184 /* Compare what was read against the data written */
185 if ((rdbuf[0] != wrbuf[1]) || (rdbuf[1] != wrbuf[2]) ||
186 (rdbuf[2] != es) || (memcmp(data, &rdbuf[3], len) != 0))
187 return -1;
188
189 /* Copy the scratchpad to EEPROM */
190 if (w1_reset_select_slave(sl))
191 return -1;
192
193 wrbuf[0] = W1_F23_COPY_SCRATCH;
194 wrbuf[3] = es;
195 w1_write_block(sl->master, wrbuf, 4);
196
197 /* Sleep for 5 ms to wait for the write to complete */
198 msleep(5);
199
200 /* Reset the bus to wake up the EEPROM (this may not be needed) */
201 w1_reset_bus(sl->master);
Ben Gardnerdca17142009-02-27 14:02:58 -0800202#ifdef CONFIG_W1_SLAVE_DS2433_CRC
203 f23->validcrc &= ~(1 << (addr >> W1_PAGE_BITS));
204#endif
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400205 return 0;
206}
207
Zhang Rui91a69022007-06-09 13:57:22 +0800208static ssize_t w1_f23_write_bin(struct kobject *kobj,
209 struct bin_attribute *bin_attr,
210 char *buf, loff_t off, size_t count)
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400211{
212 struct w1_slave *sl = kobj_to_w1_slave(kobj);
213 int addr, len, idx;
214
215 if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
216 return 0;
217
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -0800218#ifdef CONFIG_W1_SLAVE_DS2433_CRC
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400219 /* can only write full blocks in cached mode */
220 if ((off & W1_PAGE_MASK) || (count & W1_PAGE_MASK)) {
Evgeniy Polyakovf24ec7f2005-09-12 17:12:43 +0400221 dev_err(&sl->dev, "invalid offset/count off=%d cnt=%zd\n",
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400222 (int)off, count);
223 return -EINVAL;
224 }
225
226 /* make sure the block CRCs are valid */
227 for (idx = 0; idx < count; idx += W1_PAGE_SIZE) {
228 if (crc16(CRC16_INIT, &buf[idx], W1_PAGE_SIZE) != CRC16_VALID) {
229 dev_err(&sl->dev, "bad CRC at offset %d\n", (int)off);
230 return -EINVAL;
231 }
232 }
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -0800233#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400234
Evgeniy Polyakovabd52a12006-04-03 12:04:27 +0400235 mutex_lock(&sl->master->mutex);
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400236
237 /* Can only write data to one page at a time */
238 idx = 0;
239 while (idx < count) {
240 addr = off + idx;
241 len = W1_PAGE_SIZE - (addr & W1_PAGE_MASK);
242 if (len > (count - idx))
243 len = count - idx;
244
245 if (w1_f23_write(sl, addr, len, &buf[idx]) < 0) {
246 count = -EIO;
247 goto out_up;
248 }
249 idx += len;
250 }
251
252out_up:
Evgeniy Polyakovabd52a12006-04-03 12:04:27 +0400253 mutex_unlock(&sl->master->mutex);
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400254
255 return count;
256}
257
258static struct bin_attribute w1_f23_bin_attr = {
259 .attr = {
260 .name = "eeprom",
261 .mode = S_IRUGO | S_IWUSR,
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400262 },
263 .size = W1_EEPROM_SIZE,
264 .read = w1_f23_read_bin,
265 .write = w1_f23_write_bin,
266};
267
268static int w1_f23_add_slave(struct w1_slave *sl)
269{
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400270 int err;
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -0800271#ifdef CONFIG_W1_SLAVE_DS2433_CRC
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400272 struct w1_f23_data *data;
273
Yoann Padioleaudd00cc42007-07-19 01:49:03 -0700274 data = kzalloc(sizeof(struct w1_f23_data), GFP_KERNEL);
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400275 if (!data)
276 return -ENOMEM;
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400277 sl->family_data = data;
278
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -0800279#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400280
281 err = sysfs_create_bin_file(&sl->dev.kobj, &w1_f23_bin_attr);
282
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -0800283#ifdef CONFIG_W1_SLAVE_DS2433_CRC
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400284 if (err)
285 kfree(data);
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -0800286#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400287
288 return err;
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400289}
290
291static void w1_f23_remove_slave(struct w1_slave *sl)
292{
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -0800293#ifdef CONFIG_W1_SLAVE_DS2433_CRC
Jesper Juhl6044ec82005-11-07 01:01:32 -0800294 kfree(sl->family_data);
295 sl->family_data = NULL;
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -0800296#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400297 sysfs_remove_bin_file(&sl->dev.kobj, &w1_f23_bin_attr);
298}
299
300static struct w1_family_ops w1_f23_fops = {
301 .add_slave = w1_f23_add_slave,
302 .remove_slave = w1_f23_remove_slave,
303};
304
305static struct w1_family w1_family_23 = {
306 .fid = W1_EEPROM_DS2433,
307 .fops = &w1_f23_fops,
308};
309
310static int __init w1_f23_init(void)
311{
312 return w1_register_family(&w1_family_23);
313}
314
315static void __exit w1_f23_fini(void)
316{
317 w1_unregister_family(&w1_family_23);
318}
319
320module_init(w1_f23_init);
321module_exit(w1_f23_fini);