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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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090016#include <linux/slab.h>
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -080017#ifdef CONFIG_W1_SLAVE_DS2433_CRC
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +040018#include <linux/crc16.h>
Evgeniy Polyakovf24ec7f2005-09-12 17:12:43 +040019
20#define CRC16_INIT 0
21#define CRC16_VALID 0xb001
22
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +040023#endif
Evgeniy Polyakov80895392005-08-11 17:27:50 +040024
Evgeniy Polyakovbd529cf2005-12-06 13:38:28 +030025#include "../w1.h"
Evgeniy Polyakovbd529cf2005-12-06 13:38:28 +030026#include "../w1_int.h"
27#include "../w1_family.h"
Evgeniy Polyakov80895392005-08-11 17:27:50 +040028
Evgeniy Polyakov80895392005-08-11 17:27:50 +040029#define W1_EEPROM_SIZE 512
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +040030#define W1_PAGE_COUNT 16
Evgeniy Polyakov80895392005-08-11 17:27:50 +040031#define W1_PAGE_SIZE 32
32#define W1_PAGE_BITS 5
33#define W1_PAGE_MASK 0x1F
34
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +040035#define W1_F23_TIME 300
36
Evgeniy Polyakov80895392005-08-11 17:27:50 +040037#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
41
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +040042struct w1_f23_data {
43 u8 memory[W1_EEPROM_SIZE];
44 u32 validcrc;
45};
46
Evgeniy Polyakov80895392005-08-11 17:27:50 +040047/**
48 * Check the file size bounds and adjusts count as needed.
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +040049 * This would not be needed if the file size didn't reset to 0 after a write.
Evgeniy Polyakov80895392005-08-11 17:27:50 +040050 */
51static inline size_t w1_f23_fix_count(loff_t off, size_t count, size_t size)
52{
53 if (off > size)
54 return 0;
55
56 if ((off + count) > size)
57 return (size - off);
58
59 return count;
60}
61
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -080062#ifdef CONFIG_W1_SLAVE_DS2433_CRC
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +040063static int w1_f23_refresh_block(struct w1_slave *sl, struct w1_f23_data *data,
64 int block)
65{
66 u8 wrbuf[3];
67 int off = block * W1_PAGE_SIZE;
68
69 if (data->validcrc & (1 << block))
70 return 0;
71
72 if (w1_reset_select_slave(sl)) {
73 data->validcrc = 0;
74 return -EIO;
75 }
76
77 wrbuf[0] = W1_F23_READ_EEPROM;
78 wrbuf[1] = off & 0xff;
79 wrbuf[2] = off >> 8;
80 w1_write_block(sl->master, wrbuf, 3);
81 w1_read_block(sl->master, &data->memory[off], W1_PAGE_SIZE);
82
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);
86
87 return 0;
88}
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -080089#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +040090
Greg Kroah-Hartman38f40982013-08-21 15:45:01 -070091static ssize_t eeprom_read(struct file *filp, struct kobject *kobj,
92 struct bin_attribute *bin_attr, char *buf,
93 loff_t off, size_t count)
Evgeniy Polyakov80895392005-08-11 17:27:50 +040094{
95 struct w1_slave *sl = kobj_to_w1_slave(kobj);
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -080096#ifdef CONFIG_W1_SLAVE_DS2433_CRC
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +040097 struct w1_f23_data *data = sl->family_data;
98 int i, min_page, max_page;
99#else
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400100 u8 wrbuf[3];
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400101#endif
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400102
103 if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
104 return 0;
105
NeilBrownb02f8be2012-05-18 15:59:52 +1000106 mutex_lock(&sl->master->bus_mutex);
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400107
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -0800108#ifdef CONFIG_W1_SLAVE_DS2433_CRC
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400109
110 min_page = (off >> W1_PAGE_BITS);
111 max_page = (off + count - 1) >> W1_PAGE_BITS;
112 for (i = min_page; i <= max_page; i++) {
113 if (w1_f23_refresh_block(sl, data, i)) {
114 count = -EIO;
115 goto out_up;
116 }
117 }
118 memcpy(buf, &data->memory[off], count);
119
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -0800120#else /* CONFIG_W1_SLAVE_DS2433_CRC */
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400121
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400122 /* read directly from the EEPROM */
123 if (w1_reset_select_slave(sl)) {
124 count = -EIO;
125 goto out_up;
126 }
127
128 wrbuf[0] = W1_F23_READ_EEPROM;
129 wrbuf[1] = off & 0xff;
130 wrbuf[2] = off >> 8;
131 w1_write_block(sl->master, wrbuf, 3);
132 w1_read_block(sl->master, buf, count);
133
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -0800134#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400135
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400136out_up:
NeilBrownb02f8be2012-05-18 15:59:52 +1000137 mutex_unlock(&sl->master->bus_mutex);
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400138
139 return count;
140}
141
142/**
143 * Writes to the scratchpad and reads it back for verification.
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400144 * Then copies the scratchpad to EEPROM.
145 * The data must be on one page.
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400146 * The master must be locked.
147 *
148 * @param sl The slave structure
149 * @param addr Address for the write
150 * @param len length must be <= (W1_PAGE_SIZE - (addr & W1_PAGE_MASK))
151 * @param data The data to write
152 * @return 0=Success -1=failure
153 */
154static int w1_f23_write(struct w1_slave *sl, int addr, int len, const u8 *data)
155{
Ben Gardnerdca17142009-02-27 14:02:58 -0800156#ifdef CONFIG_W1_SLAVE_DS2433_CRC
157 struct w1_f23_data *f23 = sl->family_data;
158#endif
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400159 u8 wrbuf[4];
160 u8 rdbuf[W1_PAGE_SIZE + 3];
161 u8 es = (addr + len - 1) & 0x1f;
162
163 /* Write the data to the scratchpad */
164 if (w1_reset_select_slave(sl))
165 return -1;
166
167 wrbuf[0] = W1_F23_WRITE_SCRATCH;
168 wrbuf[1] = addr & 0xff;
169 wrbuf[2] = addr >> 8;
170
171 w1_write_block(sl->master, wrbuf, 3);
172 w1_write_block(sl->master, data, len);
173
174 /* Read the scratchpad and verify */
175 if (w1_reset_select_slave(sl))
176 return -1;
177
178 w1_write_8(sl->master, W1_F23_READ_SCRATCH);
179 w1_read_block(sl->master, rdbuf, len + 3);
180
181 /* Compare what was read against the data written */
182 if ((rdbuf[0] != wrbuf[1]) || (rdbuf[1] != wrbuf[2]) ||
183 (rdbuf[2] != es) || (memcmp(data, &rdbuf[3], len) != 0))
184 return -1;
185
186 /* Copy the scratchpad to EEPROM */
187 if (w1_reset_select_slave(sl))
188 return -1;
189
190 wrbuf[0] = W1_F23_COPY_SCRATCH;
191 wrbuf[3] = es;
192 w1_write_block(sl->master, wrbuf, 4);
193
194 /* Sleep for 5 ms to wait for the write to complete */
195 msleep(5);
196
197 /* Reset the bus to wake up the EEPROM (this may not be needed) */
198 w1_reset_bus(sl->master);
Ben Gardnerdca17142009-02-27 14:02:58 -0800199#ifdef CONFIG_W1_SLAVE_DS2433_CRC
200 f23->validcrc &= ~(1 << (addr >> W1_PAGE_BITS));
201#endif
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400202 return 0;
203}
204
Greg Kroah-Hartman38f40982013-08-21 15:45:01 -0700205static ssize_t eeprom_write(struct file *filp, struct kobject *kobj,
206 struct bin_attribute *bin_attr, char *buf,
207 loff_t off, size_t count)
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400208{
209 struct w1_slave *sl = kobj_to_w1_slave(kobj);
210 int addr, len, idx;
211
212 if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
213 return 0;
214
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -0800215#ifdef CONFIG_W1_SLAVE_DS2433_CRC
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400216 /* can only write full blocks in cached mode */
217 if ((off & W1_PAGE_MASK) || (count & W1_PAGE_MASK)) {
Evgeniy Polyakovf24ec7f2005-09-12 17:12:43 +0400218 dev_err(&sl->dev, "invalid offset/count off=%d cnt=%zd\n",
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400219 (int)off, count);
220 return -EINVAL;
221 }
222
223 /* make sure the block CRCs are valid */
224 for (idx = 0; idx < count; idx += W1_PAGE_SIZE) {
225 if (crc16(CRC16_INIT, &buf[idx], W1_PAGE_SIZE) != CRC16_VALID) {
226 dev_err(&sl->dev, "bad CRC at offset %d\n", (int)off);
227 return -EINVAL;
228 }
229 }
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -0800230#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400231
NeilBrownb02f8be2012-05-18 15:59:52 +1000232 mutex_lock(&sl->master->bus_mutex);
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400233
234 /* Can only write data to one page at a time */
235 idx = 0;
236 while (idx < count) {
237 addr = off + idx;
238 len = W1_PAGE_SIZE - (addr & W1_PAGE_MASK);
239 if (len > (count - idx))
240 len = count - idx;
241
242 if (w1_f23_write(sl, addr, len, &buf[idx]) < 0) {
243 count = -EIO;
244 goto out_up;
245 }
246 idx += len;
247 }
248
249out_up:
NeilBrownb02f8be2012-05-18 15:59:52 +1000250 mutex_unlock(&sl->master->bus_mutex);
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400251
252 return count;
253}
254
Greg Kroah-Hartman38f40982013-08-21 15:45:01 -0700255static BIN_ATTR_RW(eeprom, W1_EEPROM_SIZE);
256
257static struct bin_attribute *w1_f23_bin_attributes[] = {
258 &bin_attr_eeprom,
259 NULL,
260};
261
262static const struct attribute_group w1_f23_group = {
263 .bin_attrs = w1_f23_bin_attributes,
264};
265
266static const struct attribute_group *w1_f23_groups[] = {
267 &w1_f23_group,
268 NULL,
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400269};
270
271static int w1_f23_add_slave(struct w1_slave *sl)
272{
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -0800273#ifdef CONFIG_W1_SLAVE_DS2433_CRC
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400274 struct w1_f23_data *data;
275
Yoann Padioleaudd00cc42007-07-19 01:49:03 -0700276 data = kzalloc(sizeof(struct w1_f23_data), GFP_KERNEL);
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400277 if (!data)
278 return -ENOMEM;
Evgeniy Polyakov0a25e4d2005-08-17 15:24:37 +0400279 sl->family_data = data;
280
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -0800281#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
Greg Kroah-Hartman38f40982013-08-21 15:45:01 -0700282 return 0;
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400283}
284
285static void w1_f23_remove_slave(struct w1_slave *sl)
286{
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -0800287#ifdef CONFIG_W1_SLAVE_DS2433_CRC
Jesper Juhl6044ec82005-11-07 01:01:32 -0800288 kfree(sl->family_data);
289 sl->family_data = NULL;
Evgeniy Polyakove9d55f92006-12-06 20:39:27 -0800290#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400291}
292
293static struct w1_family_ops w1_f23_fops = {
294 .add_slave = w1_f23_add_slave,
295 .remove_slave = w1_f23_remove_slave,
Greg Kroah-Hartman38f40982013-08-21 15:45:01 -0700296 .groups = w1_f23_groups,
Evgeniy Polyakov80895392005-08-11 17:27:50 +0400297};
298
299static struct w1_family w1_family_23 = {
300 .fid = W1_EEPROM_DS2433,
301 .fops = &w1_f23_fops,
302};
Andrew F. Davis939fc832016-08-02 14:07:09 -0700303module_w1_family(w1_family_23);
Andrew F. Davis50fa2952017-05-16 15:02:12 -0500304
305MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
306MODULE_DESCRIPTION("w1 family 23 driver for DS2433, 4kb EEPROM");
307MODULE_LICENSE("GPL");
308MODULE_ALIAS("w1-family-" __stringify(W1_EEPROM_DS2433));