forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
311 lines
7.1 KiB
311 lines
7.1 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* w1_ds2805 - w1 family 0d (DS28E05) driver |
|
* |
|
* Copyright (c) 2016 Andrew Worsley [email protected] |
|
*/ |
|
|
|
#include <linux/kernel.h> |
|
#include <linux/module.h> |
|
#include <linux/moduleparam.h> |
|
#include <linux/device.h> |
|
#include <linux/types.h> |
|
#include <linux/delay.h> |
|
|
|
#include <linux/w1.h> |
|
|
|
#define W1_EEPROM_DS2805 0x0D |
|
|
|
#define W1_F0D_EEPROM_SIZE 128 |
|
#define W1_F0D_PAGE_BITS 3 |
|
#define W1_F0D_PAGE_SIZE (1<<W1_F0D_PAGE_BITS) |
|
#define W1_F0D_PAGE_MASK 0x0F |
|
|
|
#define W1_F0D_SCRATCH_BITS 1 |
|
#define W1_F0D_SCRATCH_SIZE (1<<W1_F0D_SCRATCH_BITS) |
|
#define W1_F0D_SCRATCH_MASK (W1_F0D_SCRATCH_SIZE-1) |
|
|
|
#define W1_F0D_READ_EEPROM 0xF0 |
|
#define W1_F0D_WRITE_EEPROM 0x55 |
|
#define W1_F0D_RELEASE 0xFF |
|
|
|
#define W1_F0D_CS_OK 0xAA /* Chip Status Ok */ |
|
|
|
#define W1_F0D_TPROG_MS 16 |
|
|
|
#define W1_F0D_READ_RETRIES 10 |
|
#define W1_F0D_READ_MAXLEN W1_F0D_EEPROM_SIZE |
|
|
|
/* |
|
* Check the file size bounds and adjusts count as needed. |
|
* This would not be needed if the file size didn't reset to 0 after a write. |
|
*/ |
|
static inline size_t w1_f0d_fix_count(loff_t off, size_t count, size_t size) |
|
{ |
|
if (off > size) |
|
return 0; |
|
|
|
if ((off + count) > size) |
|
return size - off; |
|
|
|
return count; |
|
} |
|
|
|
/* |
|
* Read a block from W1 ROM two times and compares the results. |
|
* If they are equal they are returned, otherwise the read |
|
* is repeated W1_F0D_READ_RETRIES times. |
|
* |
|
* count must not exceed W1_F0D_READ_MAXLEN. |
|
*/ |
|
static int w1_f0d_readblock(struct w1_slave *sl, int off, int count, char *buf) |
|
{ |
|
u8 wrbuf[3]; |
|
u8 cmp[W1_F0D_READ_MAXLEN]; |
|
int tries = W1_F0D_READ_RETRIES; |
|
|
|
do { |
|
wrbuf[0] = W1_F0D_READ_EEPROM; |
|
wrbuf[1] = off & 0x7f; |
|
wrbuf[2] = 0; |
|
|
|
if (w1_reset_select_slave(sl)) |
|
return -1; |
|
|
|
w1_write_block(sl->master, wrbuf, sizeof(wrbuf)); |
|
w1_read_block(sl->master, buf, count); |
|
|
|
if (w1_reset_select_slave(sl)) |
|
return -1; |
|
|
|
w1_write_block(sl->master, wrbuf, sizeof(wrbuf)); |
|
w1_read_block(sl->master, cmp, count); |
|
|
|
if (!memcmp(cmp, buf, count)) |
|
return 0; |
|
} while (--tries); |
|
|
|
dev_err(&sl->dev, "proof reading failed %d times\n", |
|
W1_F0D_READ_RETRIES); |
|
|
|
return -1; |
|
} |
|
|
|
static ssize_t w1_f0d_read_bin(struct file *filp, struct kobject *kobj, |
|
struct bin_attribute *bin_attr, |
|
char *buf, loff_t off, size_t count) |
|
{ |
|
struct w1_slave *sl = kobj_to_w1_slave(kobj); |
|
int todo = count; |
|
|
|
count = w1_f0d_fix_count(off, count, W1_F0D_EEPROM_SIZE); |
|
if (count == 0) |
|
return 0; |
|
|
|
mutex_lock(&sl->master->mutex); |
|
|
|
/* read directly from the EEPROM in chunks of W1_F0D_READ_MAXLEN */ |
|
while (todo > 0) { |
|
int block_read; |
|
|
|
if (todo >= W1_F0D_READ_MAXLEN) |
|
block_read = W1_F0D_READ_MAXLEN; |
|
else |
|
block_read = todo; |
|
|
|
if (w1_f0d_readblock(sl, off, block_read, buf) < 0) { |
|
count = -EIO; |
|
break; |
|
} |
|
|
|
todo -= W1_F0D_READ_MAXLEN; |
|
buf += W1_F0D_READ_MAXLEN; |
|
off += W1_F0D_READ_MAXLEN; |
|
} |
|
|
|
mutex_unlock(&sl->master->mutex); |
|
|
|
return count; |
|
} |
|
|
|
/* |
|
* Writes to the scratchpad and reads it back for verification. |
|
* Then copies the scratchpad to EEPROM. |
|
* The data must be aligned at W1_F0D_SCRATCH_SIZE bytes and |
|
* must be W1_F0D_SCRATCH_SIZE bytes long. |
|
* The master must be locked. |
|
* |
|
* @param sl The slave structure |
|
* @param addr Address for the write |
|
* @param len length must be <= (W1_F0D_PAGE_SIZE - (addr & W1_F0D_PAGE_MASK)) |
|
* @param data The data to write |
|
* @return 0=Success -1=failure |
|
*/ |
|
static int w1_f0d_write(struct w1_slave *sl, int addr, int len, const u8 *data) |
|
{ |
|
int tries = W1_F0D_READ_RETRIES; |
|
u8 wrbuf[3]; |
|
u8 rdbuf[W1_F0D_SCRATCH_SIZE]; |
|
u8 cs; |
|
|
|
if ((addr & 1) || (len != 2)) { |
|
dev_err(&sl->dev, "%s: bad addr/len - addr=%#x len=%d\n", |
|
__func__, addr, len); |
|
return -1; |
|
} |
|
|
|
retry: |
|
|
|
/* Write the data to the scratchpad */ |
|
if (w1_reset_select_slave(sl)) |
|
return -1; |
|
|
|
wrbuf[0] = W1_F0D_WRITE_EEPROM; |
|
wrbuf[1] = addr & 0xff; |
|
wrbuf[2] = 0xff; /* ?? from Example */ |
|
|
|
w1_write_block(sl->master, wrbuf, sizeof(wrbuf)); |
|
w1_write_block(sl->master, data, len); |
|
|
|
w1_read_block(sl->master, rdbuf, sizeof(rdbuf)); |
|
/* Compare what was read against the data written */ |
|
if ((rdbuf[0] != data[0]) || (rdbuf[1] != data[1])) { |
|
|
|
if (--tries) |
|
goto retry; |
|
|
|
dev_err(&sl->dev, |
|
"could not write to eeprom, scratchpad compare failed %d times\n", |
|
W1_F0D_READ_RETRIES); |
|
pr_info("%s: rdbuf = %#x %#x data = %#x %#x\n", |
|
__func__, rdbuf[0], rdbuf[1], data[0], data[1]); |
|
|
|
return -1; |
|
} |
|
|
|
/* Trigger write out to EEPROM */ |
|
w1_write_8(sl->master, W1_F0D_RELEASE); |
|
|
|
/* Sleep for tprog ms to wait for the write to complete */ |
|
msleep(W1_F0D_TPROG_MS); |
|
|
|
/* Check CS (Command Status) == 0xAA ? */ |
|
cs = w1_read_8(sl->master); |
|
if (cs != W1_F0D_CS_OK) { |
|
dev_err(&sl->dev, "save to eeprom failed = CS=%#x\n", cs); |
|
return -1; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static ssize_t w1_f0d_write_bin(struct file *filp, struct kobject *kobj, |
|
struct bin_attribute *bin_attr, |
|
char *buf, loff_t off, size_t count) |
|
{ |
|
struct w1_slave *sl = kobj_to_w1_slave(kobj); |
|
int addr, len; |
|
int copy; |
|
|
|
count = w1_f0d_fix_count(off, count, W1_F0D_EEPROM_SIZE); |
|
if (count == 0) |
|
return 0; |
|
|
|
mutex_lock(&sl->master->mutex); |
|
|
|
/* Can only write data in blocks of the size of the scratchpad */ |
|
addr = off; |
|
len = count; |
|
while (len > 0) { |
|
|
|
/* if len too short or addr not aligned */ |
|
if (len < W1_F0D_SCRATCH_SIZE || addr & W1_F0D_SCRATCH_MASK) { |
|
char tmp[W1_F0D_SCRATCH_SIZE]; |
|
|
|
/* read the block and update the parts to be written */ |
|
if (w1_f0d_readblock(sl, addr & ~W1_F0D_SCRATCH_MASK, |
|
W1_F0D_SCRATCH_SIZE, tmp)) { |
|
count = -EIO; |
|
goto out_up; |
|
} |
|
|
|
/* copy at most to the boundary of the PAGE or len */ |
|
copy = W1_F0D_SCRATCH_SIZE - |
|
(addr & W1_F0D_SCRATCH_MASK); |
|
|
|
if (copy > len) |
|
copy = len; |
|
|
|
memcpy(&tmp[addr & W1_F0D_SCRATCH_MASK], buf, copy); |
|
if (w1_f0d_write(sl, addr & ~W1_F0D_SCRATCH_MASK, |
|
W1_F0D_SCRATCH_SIZE, tmp) < 0) { |
|
count = -EIO; |
|
goto out_up; |
|
} |
|
} else { |
|
|
|
copy = W1_F0D_SCRATCH_SIZE; |
|
if (w1_f0d_write(sl, addr, copy, buf) < 0) { |
|
count = -EIO; |
|
goto out_up; |
|
} |
|
} |
|
buf += copy; |
|
addr += copy; |
|
len -= copy; |
|
} |
|
|
|
out_up: |
|
mutex_unlock(&sl->master->mutex); |
|
|
|
return count; |
|
} |
|
|
|
static struct bin_attribute w1_f0d_bin_attr = { |
|
.attr = { |
|
.name = "eeprom", |
|
.mode = S_IRUGO | S_IWUSR, |
|
}, |
|
.size = W1_F0D_EEPROM_SIZE, |
|
.read = w1_f0d_read_bin, |
|
.write = w1_f0d_write_bin, |
|
}; |
|
|
|
static int w1_f0d_add_slave(struct w1_slave *sl) |
|
{ |
|
return sysfs_create_bin_file(&sl->dev.kobj, &w1_f0d_bin_attr); |
|
} |
|
|
|
static void w1_f0d_remove_slave(struct w1_slave *sl) |
|
{ |
|
sysfs_remove_bin_file(&sl->dev.kobj, &w1_f0d_bin_attr); |
|
} |
|
|
|
static const struct w1_family_ops w1_f0d_fops = { |
|
.add_slave = w1_f0d_add_slave, |
|
.remove_slave = w1_f0d_remove_slave, |
|
}; |
|
|
|
static struct w1_family w1_family_0d = { |
|
.fid = W1_EEPROM_DS2805, |
|
.fops = &w1_f0d_fops, |
|
}; |
|
|
|
static int __init w1_f0d_init(void) |
|
{ |
|
pr_info("%s()\n", __func__); |
|
return w1_register_family(&w1_family_0d); |
|
} |
|
|
|
static void __exit w1_f0d_fini(void) |
|
{ |
|
pr_info("%s()\n", __func__); |
|
w1_unregister_family(&w1_family_0d); |
|
} |
|
|
|
module_init(w1_f0d_init); |
|
module_exit(w1_f0d_fini); |
|
|
|
MODULE_LICENSE("GPL"); |
|
MODULE_AUTHOR("Andrew Worsley [email protected]"); |
|
MODULE_DESCRIPTION("w1 family 0d driver for DS2805, 1kb EEPROM");
|
|
|