140b0b3f8SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only
2bd529cfbSEvgeniy Polyakov /*
3bd529cfbSEvgeniy Polyakov * w1_ds2433.c - w1 family 23 (DS2433) driver
4bd529cfbSEvgeniy Polyakov *
5bd529cfbSEvgeniy Polyakov * Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com>
6bd529cfbSEvgeniy Polyakov */
7bd529cfbSEvgeniy Polyakov
8bd529cfbSEvgeniy Polyakov #include <linux/kernel.h>
9bd529cfbSEvgeniy Polyakov #include <linux/module.h>
10bd529cfbSEvgeniy Polyakov #include <linux/moduleparam.h>
11bd529cfbSEvgeniy Polyakov #include <linux/device.h>
12bd529cfbSEvgeniy Polyakov #include <linux/types.h>
13bd529cfbSEvgeniy Polyakov #include <linux/delay.h>
145a0e3ad6STejun Heo #include <linux/slab.h>
15e9d55f9dSEvgeniy Polyakov #ifdef CONFIG_W1_SLAVE_DS2433_CRC
16bd529cfbSEvgeniy Polyakov #include <linux/crc16.h>
17bd529cfbSEvgeniy Polyakov
18bd529cfbSEvgeniy Polyakov #define CRC16_INIT 0
19bd529cfbSEvgeniy Polyakov #define CRC16_VALID 0xb001
20bd529cfbSEvgeniy Polyakov
21bd529cfbSEvgeniy Polyakov #endif
22bd529cfbSEvgeniy Polyakov
23de0d6dbdSAndrew F. Davis #include <linux/w1.h>
24de0d6dbdSAndrew F. Davis
25de0d6dbdSAndrew F. Davis #define W1_EEPROM_DS2433 0x23
26bd529cfbSEvgeniy Polyakov
27bd529cfbSEvgeniy Polyakov #define W1_EEPROM_SIZE 512
28bd529cfbSEvgeniy Polyakov #define W1_PAGE_COUNT 16
29bd529cfbSEvgeniy Polyakov #define W1_PAGE_SIZE 32
30bd529cfbSEvgeniy Polyakov #define W1_PAGE_BITS 5
31bd529cfbSEvgeniy Polyakov #define W1_PAGE_MASK 0x1F
32bd529cfbSEvgeniy Polyakov
33bd529cfbSEvgeniy Polyakov #define W1_F23_TIME 300
34bd529cfbSEvgeniy Polyakov
35bd529cfbSEvgeniy Polyakov #define W1_F23_READ_EEPROM 0xF0
36bd529cfbSEvgeniy Polyakov #define W1_F23_WRITE_SCRATCH 0x0F
37bd529cfbSEvgeniy Polyakov #define W1_F23_READ_SCRATCH 0xAA
38bd529cfbSEvgeniy Polyakov #define W1_F23_COPY_SCRATCH 0x55
39bd529cfbSEvgeniy Polyakov
40bd529cfbSEvgeniy Polyakov struct w1_f23_data {
41bd529cfbSEvgeniy Polyakov u8 memory[W1_EEPROM_SIZE];
42bd529cfbSEvgeniy Polyakov u32 validcrc;
43bd529cfbSEvgeniy Polyakov };
44bd529cfbSEvgeniy Polyakov
45a866ce3bSKrzysztof Kozlowski /*
46bd529cfbSEvgeniy Polyakov * Check the file size bounds and adjusts count as needed.
47bd529cfbSEvgeniy Polyakov * This would not be needed if the file size didn't reset to 0 after a write.
48bd529cfbSEvgeniy Polyakov */
w1_f23_fix_count(loff_t off,size_t count,size_t size)49bd529cfbSEvgeniy Polyakov static inline size_t w1_f23_fix_count(loff_t off, size_t count, size_t size)
50bd529cfbSEvgeniy Polyakov {
51bd529cfbSEvgeniy Polyakov if (off > size)
52bd529cfbSEvgeniy Polyakov return 0;
53bd529cfbSEvgeniy Polyakov
54bd529cfbSEvgeniy Polyakov if ((off + count) > size)
55bd529cfbSEvgeniy Polyakov return (size - off);
56bd529cfbSEvgeniy Polyakov
57bd529cfbSEvgeniy Polyakov return count;
58bd529cfbSEvgeniy Polyakov }
59bd529cfbSEvgeniy Polyakov
60e9d55f9dSEvgeniy Polyakov #ifdef CONFIG_W1_SLAVE_DS2433_CRC
w1_f23_refresh_block(struct w1_slave * sl,struct w1_f23_data * data,int block)61bd529cfbSEvgeniy Polyakov static int w1_f23_refresh_block(struct w1_slave *sl, struct w1_f23_data *data,
62bd529cfbSEvgeniy Polyakov int block)
63bd529cfbSEvgeniy Polyakov {
64bd529cfbSEvgeniy Polyakov u8 wrbuf[3];
65bd529cfbSEvgeniy Polyakov int off = block * W1_PAGE_SIZE;
66bd529cfbSEvgeniy Polyakov
67bd529cfbSEvgeniy Polyakov if (data->validcrc & (1 << block))
68bd529cfbSEvgeniy Polyakov return 0;
69bd529cfbSEvgeniy Polyakov
70bd529cfbSEvgeniy Polyakov if (w1_reset_select_slave(sl)) {
71bd529cfbSEvgeniy Polyakov data->validcrc = 0;
72bd529cfbSEvgeniy Polyakov return -EIO;
73bd529cfbSEvgeniy Polyakov }
74bd529cfbSEvgeniy Polyakov
75bd529cfbSEvgeniy Polyakov wrbuf[0] = W1_F23_READ_EEPROM;
76bd529cfbSEvgeniy Polyakov wrbuf[1] = off & 0xff;
77bd529cfbSEvgeniy Polyakov wrbuf[2] = off >> 8;
78bd529cfbSEvgeniy Polyakov w1_write_block(sl->master, wrbuf, 3);
79bd529cfbSEvgeniy Polyakov w1_read_block(sl->master, &data->memory[off], W1_PAGE_SIZE);
80bd529cfbSEvgeniy Polyakov
81bd529cfbSEvgeniy Polyakov /* cache the block if the CRC is valid */
82bd529cfbSEvgeniy Polyakov if (crc16(CRC16_INIT, &data->memory[off], W1_PAGE_SIZE) == CRC16_VALID)
83bd529cfbSEvgeniy Polyakov data->validcrc |= (1 << block);
84bd529cfbSEvgeniy Polyakov
85bd529cfbSEvgeniy Polyakov return 0;
86bd529cfbSEvgeniy Polyakov }
87e9d55f9dSEvgeniy Polyakov #endif /* CONFIG_W1_SLAVE_DS2433_CRC */
88bd529cfbSEvgeniy Polyakov
eeprom_read(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)8938f40982SGreg Kroah-Hartman static ssize_t eeprom_read(struct file *filp, struct kobject *kobj,
9038f40982SGreg Kroah-Hartman struct bin_attribute *bin_attr, char *buf,
9138f40982SGreg Kroah-Hartman loff_t off, size_t count)
92bd529cfbSEvgeniy Polyakov {
93bd529cfbSEvgeniy Polyakov struct w1_slave *sl = kobj_to_w1_slave(kobj);
94e9d55f9dSEvgeniy Polyakov #ifdef CONFIG_W1_SLAVE_DS2433_CRC
95bd529cfbSEvgeniy Polyakov struct w1_f23_data *data = sl->family_data;
96bd529cfbSEvgeniy Polyakov int i, min_page, max_page;
97bd529cfbSEvgeniy Polyakov #else
98bd529cfbSEvgeniy Polyakov u8 wrbuf[3];
99bd529cfbSEvgeniy Polyakov #endif
100bd529cfbSEvgeniy Polyakov
101*39bbfdacSKrzysztof Kozlowski count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE);
102*39bbfdacSKrzysztof Kozlowski if (!count)
103bd529cfbSEvgeniy Polyakov return 0;
104bd529cfbSEvgeniy Polyakov
105b02f8bedSNeilBrown mutex_lock(&sl->master->bus_mutex);
106bd529cfbSEvgeniy Polyakov
107e9d55f9dSEvgeniy Polyakov #ifdef CONFIG_W1_SLAVE_DS2433_CRC
108bd529cfbSEvgeniy Polyakov
109bd529cfbSEvgeniy Polyakov min_page = (off >> W1_PAGE_BITS);
110bd529cfbSEvgeniy Polyakov max_page = (off + count - 1) >> W1_PAGE_BITS;
111bd529cfbSEvgeniy Polyakov for (i = min_page; i <= max_page; i++) {
112bd529cfbSEvgeniy Polyakov if (w1_f23_refresh_block(sl, data, i)) {
113bd529cfbSEvgeniy Polyakov count = -EIO;
114bd529cfbSEvgeniy Polyakov goto out_up;
115bd529cfbSEvgeniy Polyakov }
116bd529cfbSEvgeniy Polyakov }
117bd529cfbSEvgeniy Polyakov memcpy(buf, &data->memory[off], count);
118bd529cfbSEvgeniy Polyakov
119e9d55f9dSEvgeniy Polyakov #else /* CONFIG_W1_SLAVE_DS2433_CRC */
120bd529cfbSEvgeniy Polyakov
121bd529cfbSEvgeniy Polyakov /* read directly from the EEPROM */
122bd529cfbSEvgeniy Polyakov if (w1_reset_select_slave(sl)) {
123bd529cfbSEvgeniy Polyakov count = -EIO;
124bd529cfbSEvgeniy Polyakov goto out_up;
125bd529cfbSEvgeniy Polyakov }
126bd529cfbSEvgeniy Polyakov
127bd529cfbSEvgeniy Polyakov wrbuf[0] = W1_F23_READ_EEPROM;
128bd529cfbSEvgeniy Polyakov wrbuf[1] = off & 0xff;
129bd529cfbSEvgeniy Polyakov wrbuf[2] = off >> 8;
130bd529cfbSEvgeniy Polyakov w1_write_block(sl->master, wrbuf, 3);
131bd529cfbSEvgeniy Polyakov w1_read_block(sl->master, buf, count);
132bd529cfbSEvgeniy Polyakov
133e9d55f9dSEvgeniy Polyakov #endif /* CONFIG_W1_SLAVE_DS2433_CRC */
134bd529cfbSEvgeniy Polyakov
135bd529cfbSEvgeniy Polyakov out_up:
136b02f8bedSNeilBrown mutex_unlock(&sl->master->bus_mutex);
137bd529cfbSEvgeniy Polyakov
138bd529cfbSEvgeniy Polyakov return count;
139bd529cfbSEvgeniy Polyakov }
140bd529cfbSEvgeniy Polyakov
141bd529cfbSEvgeniy Polyakov /**
142a866ce3bSKrzysztof Kozlowski * w1_f23_write() - Writes to the scratchpad and reads it back for verification.
143a866ce3bSKrzysztof Kozlowski * @sl: The slave structure
144a866ce3bSKrzysztof Kozlowski * @addr: Address for the write
145a866ce3bSKrzysztof Kozlowski * @len: length must be <= (W1_PAGE_SIZE - (addr & W1_PAGE_MASK))
146a866ce3bSKrzysztof Kozlowski * @data: The data to write
147a866ce3bSKrzysztof Kozlowski *
148bd529cfbSEvgeniy Polyakov * Then copies the scratchpad to EEPROM.
149bd529cfbSEvgeniy Polyakov * The data must be on one page.
150bd529cfbSEvgeniy Polyakov * The master must be locked.
151bd529cfbSEvgeniy Polyakov *
152a866ce3bSKrzysztof Kozlowski * Return: 0=Success, -1=failure
153bd529cfbSEvgeniy Polyakov */
w1_f23_write(struct w1_slave * sl,int addr,int len,const u8 * data)154bd529cfbSEvgeniy Polyakov static int w1_f23_write(struct w1_slave *sl, int addr, int len, const u8 *data)
155bd529cfbSEvgeniy Polyakov {
156dca17146SBen Gardner #ifdef CONFIG_W1_SLAVE_DS2433_CRC
157dca17146SBen Gardner struct w1_f23_data *f23 = sl->family_data;
158dca17146SBen Gardner #endif
159bd529cfbSEvgeniy Polyakov u8 wrbuf[4];
160bd529cfbSEvgeniy Polyakov u8 rdbuf[W1_PAGE_SIZE + 3];
161bd529cfbSEvgeniy Polyakov u8 es = (addr + len - 1) & 0x1f;
162bd529cfbSEvgeniy Polyakov
163bd529cfbSEvgeniy Polyakov /* Write the data to the scratchpad */
164bd529cfbSEvgeniy Polyakov if (w1_reset_select_slave(sl))
165bd529cfbSEvgeniy Polyakov return -1;
166bd529cfbSEvgeniy Polyakov
167bd529cfbSEvgeniy Polyakov wrbuf[0] = W1_F23_WRITE_SCRATCH;
168bd529cfbSEvgeniy Polyakov wrbuf[1] = addr & 0xff;
169bd529cfbSEvgeniy Polyakov wrbuf[2] = addr >> 8;
170bd529cfbSEvgeniy Polyakov
171bd529cfbSEvgeniy Polyakov w1_write_block(sl->master, wrbuf, 3);
172bd529cfbSEvgeniy Polyakov w1_write_block(sl->master, data, len);
173bd529cfbSEvgeniy Polyakov
174bd529cfbSEvgeniy Polyakov /* Read the scratchpad and verify */
175bd529cfbSEvgeniy Polyakov if (w1_reset_select_slave(sl))
176bd529cfbSEvgeniy Polyakov return -1;
177bd529cfbSEvgeniy Polyakov
178bd529cfbSEvgeniy Polyakov w1_write_8(sl->master, W1_F23_READ_SCRATCH);
179bd529cfbSEvgeniy Polyakov w1_read_block(sl->master, rdbuf, len + 3);
180bd529cfbSEvgeniy Polyakov
181bd529cfbSEvgeniy Polyakov /* Compare what was read against the data written */
182bd529cfbSEvgeniy Polyakov if ((rdbuf[0] != wrbuf[1]) || (rdbuf[1] != wrbuf[2]) ||
183bd529cfbSEvgeniy Polyakov (rdbuf[2] != es) || (memcmp(data, &rdbuf[3], len) != 0))
184bd529cfbSEvgeniy Polyakov return -1;
185bd529cfbSEvgeniy Polyakov
186bd529cfbSEvgeniy Polyakov /* Copy the scratchpad to EEPROM */
187bd529cfbSEvgeniy Polyakov if (w1_reset_select_slave(sl))
188bd529cfbSEvgeniy Polyakov return -1;
189bd529cfbSEvgeniy Polyakov
190bd529cfbSEvgeniy Polyakov wrbuf[0] = W1_F23_COPY_SCRATCH;
191bd529cfbSEvgeniy Polyakov wrbuf[3] = es;
192bd529cfbSEvgeniy Polyakov w1_write_block(sl->master, wrbuf, 4);
193bd529cfbSEvgeniy Polyakov
194bd529cfbSEvgeniy Polyakov /* Sleep for 5 ms to wait for the write to complete */
195bd529cfbSEvgeniy Polyakov msleep(5);
196bd529cfbSEvgeniy Polyakov
197bd529cfbSEvgeniy Polyakov /* Reset the bus to wake up the EEPROM (this may not be needed) */
198bd529cfbSEvgeniy Polyakov w1_reset_bus(sl->master);
199dca17146SBen Gardner #ifdef CONFIG_W1_SLAVE_DS2433_CRC
200dca17146SBen Gardner f23->validcrc &= ~(1 << (addr >> W1_PAGE_BITS));
201dca17146SBen Gardner #endif
202bd529cfbSEvgeniy Polyakov return 0;
203bd529cfbSEvgeniy Polyakov }
204bd529cfbSEvgeniy Polyakov
eeprom_write(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)20538f40982SGreg Kroah-Hartman static ssize_t eeprom_write(struct file *filp, struct kobject *kobj,
20638f40982SGreg Kroah-Hartman struct bin_attribute *bin_attr, char *buf,
20738f40982SGreg Kroah-Hartman loff_t off, size_t count)
208bd529cfbSEvgeniy Polyakov {
209bd529cfbSEvgeniy Polyakov struct w1_slave *sl = kobj_to_w1_slave(kobj);
210bd529cfbSEvgeniy Polyakov int addr, len, idx;
211bd529cfbSEvgeniy Polyakov
212*39bbfdacSKrzysztof Kozlowski count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE);
213*39bbfdacSKrzysztof Kozlowski if (!count)
214bd529cfbSEvgeniy Polyakov return 0;
215bd529cfbSEvgeniy Polyakov
216e9d55f9dSEvgeniy Polyakov #ifdef CONFIG_W1_SLAVE_DS2433_CRC
217bd529cfbSEvgeniy Polyakov /* can only write full blocks in cached mode */
218bd529cfbSEvgeniy Polyakov if ((off & W1_PAGE_MASK) || (count & W1_PAGE_MASK)) {
219bd529cfbSEvgeniy Polyakov dev_err(&sl->dev, "invalid offset/count off=%d cnt=%zd\n",
220bd529cfbSEvgeniy Polyakov (int)off, count);
221bd529cfbSEvgeniy Polyakov return -EINVAL;
222bd529cfbSEvgeniy Polyakov }
223bd529cfbSEvgeniy Polyakov
224bd529cfbSEvgeniy Polyakov /* make sure the block CRCs are valid */
225bd529cfbSEvgeniy Polyakov for (idx = 0; idx < count; idx += W1_PAGE_SIZE) {
226bd529cfbSEvgeniy Polyakov if (crc16(CRC16_INIT, &buf[idx], W1_PAGE_SIZE) != CRC16_VALID) {
227bd529cfbSEvgeniy Polyakov dev_err(&sl->dev, "bad CRC at offset %d\n", (int)off);
228bd529cfbSEvgeniy Polyakov return -EINVAL;
229bd529cfbSEvgeniy Polyakov }
230bd529cfbSEvgeniy Polyakov }
231e9d55f9dSEvgeniy Polyakov #endif /* CONFIG_W1_SLAVE_DS2433_CRC */
232bd529cfbSEvgeniy Polyakov
233b02f8bedSNeilBrown mutex_lock(&sl->master->bus_mutex);
234bd529cfbSEvgeniy Polyakov
235bd529cfbSEvgeniy Polyakov /* Can only write data to one page at a time */
236bd529cfbSEvgeniy Polyakov idx = 0;
237bd529cfbSEvgeniy Polyakov while (idx < count) {
238bd529cfbSEvgeniy Polyakov addr = off + idx;
239bd529cfbSEvgeniy Polyakov len = W1_PAGE_SIZE - (addr & W1_PAGE_MASK);
240bd529cfbSEvgeniy Polyakov if (len > (count - idx))
241bd529cfbSEvgeniy Polyakov len = count - idx;
242bd529cfbSEvgeniy Polyakov
243bd529cfbSEvgeniy Polyakov if (w1_f23_write(sl, addr, len, &buf[idx]) < 0) {
244bd529cfbSEvgeniy Polyakov count = -EIO;
245bd529cfbSEvgeniy Polyakov goto out_up;
246bd529cfbSEvgeniy Polyakov }
247bd529cfbSEvgeniy Polyakov idx += len;
248bd529cfbSEvgeniy Polyakov }
249bd529cfbSEvgeniy Polyakov
250bd529cfbSEvgeniy Polyakov out_up:
251b02f8bedSNeilBrown mutex_unlock(&sl->master->bus_mutex);
252bd529cfbSEvgeniy Polyakov
253bd529cfbSEvgeniy Polyakov return count;
254bd529cfbSEvgeniy Polyakov }
255bd529cfbSEvgeniy Polyakov
25638f40982SGreg Kroah-Hartman static BIN_ATTR_RW(eeprom, W1_EEPROM_SIZE);
25738f40982SGreg Kroah-Hartman
25838f40982SGreg Kroah-Hartman static struct bin_attribute *w1_f23_bin_attributes[] = {
25938f40982SGreg Kroah-Hartman &bin_attr_eeprom,
26038f40982SGreg Kroah-Hartman NULL,
26138f40982SGreg Kroah-Hartman };
26238f40982SGreg Kroah-Hartman
26338f40982SGreg Kroah-Hartman static const struct attribute_group w1_f23_group = {
26438f40982SGreg Kroah-Hartman .bin_attrs = w1_f23_bin_attributes,
26538f40982SGreg Kroah-Hartman };
26638f40982SGreg Kroah-Hartman
26738f40982SGreg Kroah-Hartman static const struct attribute_group *w1_f23_groups[] = {
26838f40982SGreg Kroah-Hartman &w1_f23_group,
26938f40982SGreg Kroah-Hartman NULL,
270bd529cfbSEvgeniy Polyakov };
271bd529cfbSEvgeniy Polyakov
w1_f23_add_slave(struct w1_slave * sl)272bd529cfbSEvgeniy Polyakov static int w1_f23_add_slave(struct w1_slave *sl)
273bd529cfbSEvgeniy Polyakov {
274e9d55f9dSEvgeniy Polyakov #ifdef CONFIG_W1_SLAVE_DS2433_CRC
275bd529cfbSEvgeniy Polyakov struct w1_f23_data *data;
276bd529cfbSEvgeniy Polyakov
277dd00cc48SYoann Padioleau data = kzalloc(sizeof(struct w1_f23_data), GFP_KERNEL);
278bd529cfbSEvgeniy Polyakov if (!data)
279bd529cfbSEvgeniy Polyakov return -ENOMEM;
280bd529cfbSEvgeniy Polyakov sl->family_data = data;
281bd529cfbSEvgeniy Polyakov
282e9d55f9dSEvgeniy Polyakov #endif /* CONFIG_W1_SLAVE_DS2433_CRC */
28338f40982SGreg Kroah-Hartman return 0;
284bd529cfbSEvgeniy Polyakov }
285bd529cfbSEvgeniy Polyakov
w1_f23_remove_slave(struct w1_slave * sl)286bd529cfbSEvgeniy Polyakov static void w1_f23_remove_slave(struct w1_slave *sl)
287bd529cfbSEvgeniy Polyakov {
288e9d55f9dSEvgeniy Polyakov #ifdef CONFIG_W1_SLAVE_DS2433_CRC
289bd529cfbSEvgeniy Polyakov kfree(sl->family_data);
290bd529cfbSEvgeniy Polyakov sl->family_data = NULL;
291e9d55f9dSEvgeniy Polyakov #endif /* CONFIG_W1_SLAVE_DS2433_CRC */
292bd529cfbSEvgeniy Polyakov }
293bd529cfbSEvgeniy Polyakov
29457de2dfcSRikard Falkeborn static const struct w1_family_ops w1_f23_fops = {
295bd529cfbSEvgeniy Polyakov .add_slave = w1_f23_add_slave,
296bd529cfbSEvgeniy Polyakov .remove_slave = w1_f23_remove_slave,
29738f40982SGreg Kroah-Hartman .groups = w1_f23_groups,
298bd529cfbSEvgeniy Polyakov };
299bd529cfbSEvgeniy Polyakov
300bd529cfbSEvgeniy Polyakov static struct w1_family w1_family_23 = {
301bd529cfbSEvgeniy Polyakov .fid = W1_EEPROM_DS2433,
302bd529cfbSEvgeniy Polyakov .fops = &w1_f23_fops,
303bd529cfbSEvgeniy Polyakov };
304939fc832SAndrew F. Davis module_w1_family(w1_family_23);
30550fa2951SAndrew F. Davis
30650fa2951SAndrew F. Davis MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
30750fa2951SAndrew F. Davis MODULE_DESCRIPTION("w1 family 23 driver for DS2433, 4kb EEPROM");
30850fa2951SAndrew F. Davis MODULE_LICENSE("GPL");
30950fa2951SAndrew F. Davis MODULE_ALIAS("w1-family-" __stringify(W1_EEPROM_DS2433));
310