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22#include <asm/types.h>
23
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/moduleparam.h>
27#include <linux/sched.h>
28#include <linux/device.h>
29#include <linux/types.h>
30#include <linux/delay.h>
31
32#include "../w1.h"
33#include "../w1_int.h"
34#include "../w1_family.h"
35
36MODULE_LICENSE("GPL");
37MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
38MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family.");
39
40
41
42
43
44
45static int w1_strong_pullup = 1;
46module_param_named(strong_pullup, w1_strong_pullup, int, 0);
47
48static u8 bad_roms[][9] = {
49 {0xaa, 0x00, 0x4b, 0x46, 0xff, 0xff, 0x0c, 0x10, 0x87},
50 {}
51 };
52
53static ssize_t w1_therm_read(struct device *device,
54 struct device_attribute *attr, char *buf);
55
56static struct device_attribute w1_therm_attr =
57 __ATTR(w1_slave, S_IRUGO, w1_therm_read, NULL);
58
59static int w1_therm_add_slave(struct w1_slave *sl)
60{
61 return device_create_file(&sl->dev, &w1_therm_attr);
62}
63
64static void w1_therm_remove_slave(struct w1_slave *sl)
65{
66 device_remove_file(&sl->dev, &w1_therm_attr);
67}
68
69static struct w1_family_ops w1_therm_fops = {
70 .add_slave = w1_therm_add_slave,
71 .remove_slave = w1_therm_remove_slave,
72};
73
74static struct w1_family w1_therm_family_DS18S20 = {
75 .fid = W1_THERM_DS18S20,
76 .fops = &w1_therm_fops,
77};
78
79static struct w1_family w1_therm_family_DS18B20 = {
80 .fid = W1_THERM_DS18B20,
81 .fops = &w1_therm_fops,
82};
83
84static struct w1_family w1_therm_family_DS1822 = {
85 .fid = W1_THERM_DS1822,
86 .fops = &w1_therm_fops,
87};
88
89struct w1_therm_family_converter
90{
91 u8 broken;
92 u16 reserved;
93 struct w1_family *f;
94 int (*convert)(u8 rom[9]);
95};
96
97
98static inline int w1_DS18B20_convert_temp(u8 rom[9]);
99static inline int w1_DS18S20_convert_temp(u8 rom[9]);
100
101static struct w1_therm_family_converter w1_therm_families[] = {
102 {
103 .f = &w1_therm_family_DS18S20,
104 .convert = w1_DS18S20_convert_temp
105 },
106 {
107 .f = &w1_therm_family_DS1822,
108 .convert = w1_DS18B20_convert_temp
109 },
110 {
111 .f = &w1_therm_family_DS18B20,
112 .convert = w1_DS18B20_convert_temp
113 },
114};
115
116static inline int w1_DS18B20_convert_temp(u8 rom[9])
117{
118 int t = ((s16)rom[1] << 8) | rom[0];
119 t = t*1000/16;
120 return t;
121}
122
123static inline int w1_DS18S20_convert_temp(u8 rom[9])
124{
125 int t, h;
126
127 if (!rom[7])
128 return 0;
129
130 if (rom[1] == 0)
131 t = ((s32)rom[0] >> 1)*1000;
132 else
133 t = 1000*(-1*(s32)(0x100-rom[0]) >> 1);
134
135 t -= 250;
136 h = 1000*((s32)rom[7] - (s32)rom[6]);
137 h /= (s32)rom[7];
138 t += h;
139
140 return t;
141}
142
143static inline int w1_convert_temp(u8 rom[9], u8 fid)
144{
145 int i;
146
147 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i)
148 if (w1_therm_families[i].f->fid == fid)
149 return w1_therm_families[i].convert(rom);
150
151 return 0;
152}
153
154static int w1_therm_check_rom(u8 rom[9])
155{
156 int i;
157
158 for (i=0; i<sizeof(bad_roms)/9; ++i)
159 if (!memcmp(bad_roms[i], rom, 9))
160 return 1;
161
162 return 0;
163}
164
165static ssize_t w1_therm_read(struct device *device,
166 struct device_attribute *attr, char *buf)
167{
168 struct w1_slave *sl = dev_to_w1_slave(device);
169 struct w1_master *dev = sl->master;
170 u8 rom[9], crc, verdict;
171 int i, max_trying = 10;
172 ssize_t c = PAGE_SIZE;
173
174 mutex_lock(&dev->mutex);
175
176 memset(rom, 0, sizeof(rom));
177
178 verdict = 0;
179 crc = 0;
180
181 while (max_trying--) {
182 if (!w1_reset_select_slave(sl)) {
183 int count = 0;
184 unsigned int tm = 750;
185
186
187 if (w1_strong_pullup)
188 w1_next_pullup(dev, tm);
189 w1_write_8(dev, W1_CONVERT_TEMP);
190 if (!w1_strong_pullup)
191 msleep(tm);
192
193 if (!w1_reset_select_slave(sl)) {
194
195 w1_write_8(dev, W1_READ_SCRATCHPAD);
196 if ((count = w1_read_block(dev, rom, 9)) != 9) {
197 dev_warn(device, "w1_read_block() "
198 "returned %u instead of 9.\n",
199 count);
200 }
201
202 crc = w1_calc_crc8(rom, 8);
203
204 if (rom[8] == crc)
205 verdict = 1;
206 }
207 }
208
209 if (!w1_therm_check_rom(rom))
210 break;
211 }
212
213 for (i = 0; i < 9; ++i)
214 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", rom[i]);
215 c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n",
216 crc, (verdict) ? "YES" : "NO");
217 if (verdict)
218 memcpy(sl->rom, rom, sizeof(sl->rom));
219 else
220 dev_warn(device, "18S20 doesn't respond to CONVERT_TEMP.\n");
221
222 for (i = 0; i < 9; ++i)
223 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", sl->rom[i]);
224
225 c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n",
226 w1_convert_temp(rom, sl->family->fid));
227 mutex_unlock(&dev->mutex);
228
229 return PAGE_SIZE - c;
230}
231
232static int __init w1_therm_init(void)
233{
234 int err, i;
235
236 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
237 err = w1_register_family(w1_therm_families[i].f);
238 if (err)
239 w1_therm_families[i].broken = 1;
240 }
241
242 return 0;
243}
244
245static void __exit w1_therm_fini(void)
246{
247 int i;
248
249 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i)
250 if (!w1_therm_families[i].broken)
251 w1_unregister_family(w1_therm_families[i].f);
252}
253
254module_init(w1_therm_init);
255module_exit(w1_therm_fini);
256
