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.
428 lines
9.6 KiB
428 lines
9.6 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* w1_ds28e04.c - w1 family 1C (DS28E04) driver |
|
* |
|
* Copyright (c) 2012 Markus Franke <[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/slab.h> |
|
#include <linux/crc16.h> |
|
#include <linux/uaccess.h> |
|
|
|
#define CRC16_INIT 0 |
|
#define CRC16_VALID 0xb001 |
|
|
|
#include <linux/w1.h> |
|
|
|
#define W1_FAMILY_DS28E04 0x1C |
|
|
|
/* Allow the strong pullup to be disabled, but default to enabled. |
|
* If it was disabled a parasite powered device might not get the required |
|
* current to copy the data from the scratchpad to EEPROM. If it is enabled |
|
* parasite powered devices have a better chance of getting the current |
|
* required. |
|
*/ |
|
static int w1_strong_pullup = 1; |
|
module_param_named(strong_pullup, w1_strong_pullup, int, 0); |
|
|
|
/* enable/disable CRC checking on DS28E04-100 memory accesses */ |
|
static char w1_enable_crccheck = 1; |
|
|
|
#define W1_EEPROM_SIZE 512 |
|
#define W1_PAGE_COUNT 16 |
|
#define W1_PAGE_SIZE 32 |
|
#define W1_PAGE_BITS 5 |
|
#define W1_PAGE_MASK 0x1F |
|
|
|
#define W1_F1C_READ_EEPROM 0xF0 |
|
#define W1_F1C_WRITE_SCRATCH 0x0F |
|
#define W1_F1C_READ_SCRATCH 0xAA |
|
#define W1_F1C_COPY_SCRATCH 0x55 |
|
#define W1_F1C_ACCESS_WRITE 0x5A |
|
|
|
#define W1_1C_REG_LOGIC_STATE 0x220 |
|
|
|
struct w1_f1C_data { |
|
u8 memory[W1_EEPROM_SIZE]; |
|
u32 validcrc; |
|
}; |
|
|
|
/** |
|
* 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_f1C_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; |
|
} |
|
|
|
static int w1_f1C_refresh_block(struct w1_slave *sl, struct w1_f1C_data *data, |
|
int block) |
|
{ |
|
u8 wrbuf[3]; |
|
int off = block * W1_PAGE_SIZE; |
|
|
|
if (data->validcrc & (1 << block)) |
|
return 0; |
|
|
|
if (w1_reset_select_slave(sl)) { |
|
data->validcrc = 0; |
|
return -EIO; |
|
} |
|
|
|
wrbuf[0] = W1_F1C_READ_EEPROM; |
|
wrbuf[1] = off & 0xff; |
|
wrbuf[2] = off >> 8; |
|
w1_write_block(sl->master, wrbuf, 3); |
|
w1_read_block(sl->master, &data->memory[off], W1_PAGE_SIZE); |
|
|
|
/* cache the block if the CRC is valid */ |
|
if (crc16(CRC16_INIT, &data->memory[off], W1_PAGE_SIZE) == CRC16_VALID) |
|
data->validcrc |= (1 << block); |
|
|
|
return 0; |
|
} |
|
|
|
static int w1_f1C_read(struct w1_slave *sl, int addr, int len, char *data) |
|
{ |
|
u8 wrbuf[3]; |
|
|
|
/* read directly from the EEPROM */ |
|
if (w1_reset_select_slave(sl)) |
|
return -EIO; |
|
|
|
wrbuf[0] = W1_F1C_READ_EEPROM; |
|
wrbuf[1] = addr & 0xff; |
|
wrbuf[2] = addr >> 8; |
|
|
|
w1_write_block(sl->master, wrbuf, sizeof(wrbuf)); |
|
return w1_read_block(sl->master, data, len); |
|
} |
|
|
|
static ssize_t eeprom_read(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); |
|
struct w1_f1C_data *data = sl->family_data; |
|
int i, min_page, max_page; |
|
|
|
count = w1_f1C_fix_count(off, count, W1_EEPROM_SIZE); |
|
if (count == 0) |
|
return 0; |
|
|
|
mutex_lock(&sl->master->mutex); |
|
|
|
if (w1_enable_crccheck) { |
|
min_page = (off >> W1_PAGE_BITS); |
|
max_page = (off + count - 1) >> W1_PAGE_BITS; |
|
for (i = min_page; i <= max_page; i++) { |
|
if (w1_f1C_refresh_block(sl, data, i)) { |
|
count = -EIO; |
|
goto out_up; |
|
} |
|
} |
|
memcpy(buf, &data->memory[off], count); |
|
} else { |
|
count = w1_f1C_read(sl, off, count, buf); |
|
} |
|
|
|
out_up: |
|
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 on one page. |
|
* The master must be locked. |
|
* |
|
* @param sl The slave structure |
|
* @param addr Address for the write |
|
* @param len length must be <= (W1_PAGE_SIZE - (addr & W1_PAGE_MASK)) |
|
* @param data The data to write |
|
* @return 0=Success -1=failure |
|
*/ |
|
static int w1_f1C_write(struct w1_slave *sl, int addr, int len, const u8 *data) |
|
{ |
|
u8 wrbuf[4]; |
|
u8 rdbuf[W1_PAGE_SIZE + 3]; |
|
u8 es = (addr + len - 1) & 0x1f; |
|
unsigned int tm = 10; |
|
int i; |
|
struct w1_f1C_data *f1C = sl->family_data; |
|
|
|
/* Write the data to the scratchpad */ |
|
if (w1_reset_select_slave(sl)) |
|
return -1; |
|
|
|
wrbuf[0] = W1_F1C_WRITE_SCRATCH; |
|
wrbuf[1] = addr & 0xff; |
|
wrbuf[2] = addr >> 8; |
|
|
|
w1_write_block(sl->master, wrbuf, 3); |
|
w1_write_block(sl->master, data, len); |
|
|
|
/* Read the scratchpad and verify */ |
|
if (w1_reset_select_slave(sl)) |
|
return -1; |
|
|
|
w1_write_8(sl->master, W1_F1C_READ_SCRATCH); |
|
w1_read_block(sl->master, rdbuf, len + 3); |
|
|
|
/* Compare what was read against the data written */ |
|
if ((rdbuf[0] != wrbuf[1]) || (rdbuf[1] != wrbuf[2]) || |
|
(rdbuf[2] != es) || (memcmp(data, &rdbuf[3], len) != 0)) |
|
return -1; |
|
|
|
/* Copy the scratchpad to EEPROM */ |
|
if (w1_reset_select_slave(sl)) |
|
return -1; |
|
|
|
wrbuf[0] = W1_F1C_COPY_SCRATCH; |
|
wrbuf[3] = es; |
|
|
|
for (i = 0; i < sizeof(wrbuf); ++i) { |
|
/* issue 10ms strong pullup (or delay) on the last byte |
|
for writing the data from the scratchpad to EEPROM */ |
|
if (w1_strong_pullup && i == sizeof(wrbuf)-1) |
|
w1_next_pullup(sl->master, tm); |
|
|
|
w1_write_8(sl->master, wrbuf[i]); |
|
} |
|
|
|
if (!w1_strong_pullup) |
|
msleep(tm); |
|
|
|
if (w1_enable_crccheck) { |
|
/* invalidate cached data */ |
|
f1C->validcrc &= ~(1 << (addr >> W1_PAGE_BITS)); |
|
} |
|
|
|
/* Reset the bus to wake up the EEPROM (this may not be needed) */ |
|
w1_reset_bus(sl->master); |
|
|
|
return 0; |
|
} |
|
|
|
static ssize_t eeprom_write(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, idx; |
|
|
|
count = w1_f1C_fix_count(off, count, W1_EEPROM_SIZE); |
|
if (count == 0) |
|
return 0; |
|
|
|
if (w1_enable_crccheck) { |
|
/* can only write full blocks in cached mode */ |
|
if ((off & W1_PAGE_MASK) || (count & W1_PAGE_MASK)) { |
|
dev_err(&sl->dev, "invalid offset/count off=%d cnt=%zd\n", |
|
(int)off, count); |
|
return -EINVAL; |
|
} |
|
|
|
/* make sure the block CRCs are valid */ |
|
for (idx = 0; idx < count; idx += W1_PAGE_SIZE) { |
|
if (crc16(CRC16_INIT, &buf[idx], W1_PAGE_SIZE) |
|
!= CRC16_VALID) { |
|
dev_err(&sl->dev, "bad CRC at offset %d\n", |
|
(int)off); |
|
return -EINVAL; |
|
} |
|
} |
|
} |
|
|
|
mutex_lock(&sl->master->mutex); |
|
|
|
/* Can only write data to one page at a time */ |
|
idx = 0; |
|
while (idx < count) { |
|
addr = off + idx; |
|
len = W1_PAGE_SIZE - (addr & W1_PAGE_MASK); |
|
if (len > (count - idx)) |
|
len = count - idx; |
|
|
|
if (w1_f1C_write(sl, addr, len, &buf[idx]) < 0) { |
|
count = -EIO; |
|
goto out_up; |
|
} |
|
idx += len; |
|
} |
|
|
|
out_up: |
|
mutex_unlock(&sl->master->mutex); |
|
|
|
return count; |
|
} |
|
|
|
static BIN_ATTR_RW(eeprom, W1_EEPROM_SIZE); |
|
|
|
static ssize_t pio_read(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 ret; |
|
|
|
/* check arguments */ |
|
if (off != 0 || count != 1 || buf == NULL) |
|
return -EINVAL; |
|
|
|
mutex_lock(&sl->master->mutex); |
|
ret = w1_f1C_read(sl, W1_1C_REG_LOGIC_STATE, count, buf); |
|
mutex_unlock(&sl->master->mutex); |
|
|
|
return ret; |
|
} |
|
|
|
static ssize_t pio_write(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); |
|
u8 wrbuf[3]; |
|
u8 ack; |
|
|
|
/* check arguments */ |
|
if (off != 0 || count != 1 || buf == NULL) |
|
return -EINVAL; |
|
|
|
mutex_lock(&sl->master->mutex); |
|
|
|
/* Write the PIO data */ |
|
if (w1_reset_select_slave(sl)) { |
|
mutex_unlock(&sl->master->mutex); |
|
return -1; |
|
} |
|
|
|
/* set bit 7..2 to value '1' */ |
|
*buf = *buf | 0xFC; |
|
|
|
wrbuf[0] = W1_F1C_ACCESS_WRITE; |
|
wrbuf[1] = *buf; |
|
wrbuf[2] = ~(*buf); |
|
w1_write_block(sl->master, wrbuf, 3); |
|
|
|
w1_read_block(sl->master, &ack, sizeof(ack)); |
|
|
|
mutex_unlock(&sl->master->mutex); |
|
|
|
/* check for acknowledgement */ |
|
if (ack != 0xAA) |
|
return -EIO; |
|
|
|
return count; |
|
} |
|
|
|
static BIN_ATTR_RW(pio, 1); |
|
|
|
static ssize_t crccheck_show(struct device *dev, struct device_attribute *attr, |
|
char *buf) |
|
{ |
|
if (put_user(w1_enable_crccheck + 0x30, buf)) |
|
return -EFAULT; |
|
|
|
return sizeof(w1_enable_crccheck); |
|
} |
|
|
|
static ssize_t crccheck_store(struct device *dev, struct device_attribute *attr, |
|
const char *buf, size_t count) |
|
{ |
|
char val; |
|
|
|
if (count != 1 || !buf) |
|
return -EINVAL; |
|
|
|
if (get_user(val, buf)) |
|
return -EFAULT; |
|
|
|
/* convert to decimal */ |
|
val = val - 0x30; |
|
if (val != 0 && val != 1) |
|
return -EINVAL; |
|
|
|
/* set the new value */ |
|
w1_enable_crccheck = val; |
|
|
|
return sizeof(w1_enable_crccheck); |
|
} |
|
|
|
static DEVICE_ATTR_RW(crccheck); |
|
|
|
static struct attribute *w1_f1C_attrs[] = { |
|
&dev_attr_crccheck.attr, |
|
NULL, |
|
}; |
|
|
|
static struct bin_attribute *w1_f1C_bin_attrs[] = { |
|
&bin_attr_eeprom, |
|
&bin_attr_pio, |
|
NULL, |
|
}; |
|
|
|
static const struct attribute_group w1_f1C_group = { |
|
.attrs = w1_f1C_attrs, |
|
.bin_attrs = w1_f1C_bin_attrs, |
|
}; |
|
|
|
static const struct attribute_group *w1_f1C_groups[] = { |
|
&w1_f1C_group, |
|
NULL, |
|
}; |
|
|
|
static int w1_f1C_add_slave(struct w1_slave *sl) |
|
{ |
|
struct w1_f1C_data *data = NULL; |
|
|
|
if (w1_enable_crccheck) { |
|
data = kzalloc(sizeof(struct w1_f1C_data), GFP_KERNEL); |
|
if (!data) |
|
return -ENOMEM; |
|
sl->family_data = data; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static void w1_f1C_remove_slave(struct w1_slave *sl) |
|
{ |
|
kfree(sl->family_data); |
|
sl->family_data = NULL; |
|
} |
|
|
|
static const struct w1_family_ops w1_f1C_fops = { |
|
.add_slave = w1_f1C_add_slave, |
|
.remove_slave = w1_f1C_remove_slave, |
|
.groups = w1_f1C_groups, |
|
}; |
|
|
|
static struct w1_family w1_family_1C = { |
|
.fid = W1_FAMILY_DS28E04, |
|
.fops = &w1_f1C_fops, |
|
}; |
|
module_w1_family(w1_family_1C); |
|
|
|
MODULE_AUTHOR("Markus Franke <[email protected]>, <[email protected]>"); |
|
MODULE_DESCRIPTION("w1 family 1C driver for DS28E04, 4kb EEPROM and PIO"); |
|
MODULE_LICENSE("GPL"); |
|
MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS28E04));
|
|
|