1-wire: add ds2431 support
Based on linux implementation. Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This commit is contained in:
parent
6cb9aa9202
commit
68a961ac5c
|
@ -4,4 +4,14 @@
|
|||
|
||||
menu "1-wire Slaves"
|
||||
|
||||
config W1_SLAVE_DS2431
|
||||
bool "1kb EEPROM family support (DS2431)"
|
||||
help
|
||||
Say Y here if you want to use a 1-wire
|
||||
1kb EEPROM family device (DS2431)
|
||||
|
||||
config W1_SLAVE_DS2431_WRITE
|
||||
bool "write support"
|
||||
depends on W1_SLAVE_DS2431
|
||||
|
||||
endmenu
|
||||
|
|
|
@ -2,3 +2,4 @@
|
|||
# Makefile for the Dallas's 1-wire slaves.
|
||||
#
|
||||
|
||||
obj-$(CONFIG_W1_SLAVE_DS2431) += w1_ds2431.o
|
||||
|
|
|
@ -0,0 +1,294 @@
|
|||
/*
|
||||
* w1_ds2431.c - w1 family 2d (DS2431) driver
|
||||
*
|
||||
* Copyright (c) 2008 Bernhard Weirich <bernhard.weirich@riedel.net>
|
||||
* Copyright (c) 2012 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
|
||||
*
|
||||
* Heavily inspired by w1_DS2433 driver from Ben Gardner <bgardner@wabtec.com>
|
||||
*
|
||||
* This source code is licensed under the GNU General Public License,
|
||||
* Version 2. See the file COPYING for more details.
|
||||
*/
|
||||
|
||||
#include <init.h>
|
||||
#include "../w1.h"
|
||||
|
||||
#define W1_F2D_EEPROM_SIZE 128
|
||||
#define W1_F2D_PAGE_COUNT 4
|
||||
#define W1_F2D_PAGE_BITS 5
|
||||
#define W1_F2D_PAGE_SIZE (1 << W1_F2D_PAGE_BITS)
|
||||
#define W1_F2D_PAGE_MASK 0x1F
|
||||
|
||||
#define W1_F2D_SCRATCH_BITS 3
|
||||
#define W1_F2D_SCRATCH_SIZE (1 << W1_F2D_SCRATCH_BITS)
|
||||
#define W1_F2D_SCRATCH_MASK (W1_F2D_SCRATCH_SIZE - 1)
|
||||
|
||||
#define W1_F2D_READ_EEPROM 0xF0
|
||||
#define W1_F2D_WRITE_SCRATCH 0x0F
|
||||
#define W1_F2D_READ_SCRATCH 0xAA
|
||||
#define W1_F2D_COPY_SCRATCH 0x55
|
||||
|
||||
|
||||
#define W1_F2D_TPROG_MS 11
|
||||
|
||||
#define W1_F2D_READ_RETRIES 10
|
||||
#define W1_F2D_READ_MAXLEN 8
|
||||
|
||||
#define DRIVERNAME "ds2431"
|
||||
|
||||
static int ds2431_count = 0;
|
||||
|
||||
/*
|
||||
* 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 ds2431_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_F2D_READ_RETRIES times.
|
||||
*
|
||||
* count must not exceed W1_F2D_READ_MAXLEN.
|
||||
*/
|
||||
int ds2431_readblock(struct w1_device *dev, int off, int count, char *buf)
|
||||
{
|
||||
struct w1_bus *bus = dev->bus;
|
||||
u8 wrbuf[3];
|
||||
u8 cmp[W1_F2D_READ_MAXLEN];
|
||||
int tries = W1_F2D_READ_RETRIES;
|
||||
|
||||
do {
|
||||
wrbuf[0] = W1_F2D_READ_EEPROM;
|
||||
wrbuf[1] = off & 0xff;
|
||||
wrbuf[2] = off >> 8;
|
||||
|
||||
if (w1_reset_select_slave(dev))
|
||||
return -1;
|
||||
|
||||
w1_write_block(bus, wrbuf, 3);
|
||||
w1_read_block(bus, buf, count);
|
||||
|
||||
if (w1_reset_select_slave(dev))
|
||||
return -1;
|
||||
|
||||
w1_write_block(bus, wrbuf, 3);
|
||||
w1_read_block(bus, cmp, count);
|
||||
|
||||
if (!memcmp(cmp, buf, count))
|
||||
return 0;
|
||||
} while (--tries);
|
||||
|
||||
dev_err(&dev->dev, "proof reading failed %d times\n",
|
||||
W1_F2D_READ_RETRIES);
|
||||
|
||||
return -1;
|
||||
}
|
||||
|
||||
static ssize_t ds2431_cdev_read(struct cdev *cdev, void *buf, size_t count,
|
||||
loff_t off, ulong flags)
|
||||
{
|
||||
struct w1_device *dev = cdev->priv;
|
||||
int todo = count;
|
||||
|
||||
count = ds2431_fix_count(off, count, W1_F2D_EEPROM_SIZE);
|
||||
if (count == 0)
|
||||
return 0;
|
||||
|
||||
/* read directly from the EEPROM in chunks of W1_F2D_READ_MAXLEN */
|
||||
while (todo > 0) {
|
||||
int block_read;
|
||||
|
||||
if (todo >= W1_F2D_READ_MAXLEN)
|
||||
block_read = W1_F2D_READ_MAXLEN;
|
||||
else
|
||||
block_read = todo;
|
||||
|
||||
if (ds2431_readblock(dev, off, block_read, buf) < 0)
|
||||
count = -EIO;
|
||||
|
||||
todo -= W1_F2D_READ_MAXLEN;
|
||||
buf += W1_F2D_READ_MAXLEN;
|
||||
off += W1_F2D_READ_MAXLEN;
|
||||
}
|
||||
|
||||
return count;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_W1_SLAVE_DS2431_WRITE
|
||||
/*
|
||||
* Writes to the scratchpad and reads it back for verification.
|
||||
* Then copies the scratchpad to EEPROM.
|
||||
* The data must be aligned at W1_F2D_SCRATCH_SIZE bytes and
|
||||
* must be W1_F2D_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_F2D_PAGE_SIZE - (addr & W1_F2D_PAGE_MASK))
|
||||
* @param data The data to write
|
||||
* @return 0=Success -1=failure
|
||||
*/
|
||||
static int ds2431_write(struct w1_device *dev, int addr, int len, const u8 *data)
|
||||
{
|
||||
struct w1_bus *bus = dev->bus;
|
||||
int tries = W1_F2D_READ_RETRIES;
|
||||
u8 wrbuf[4];
|
||||
u8 rdbuf[W1_F2D_SCRATCH_SIZE + 3];
|
||||
u8 es = (addr + len - 1) % W1_F2D_SCRATCH_SIZE;
|
||||
|
||||
retry:
|
||||
|
||||
/* Write the data to the scratchpad */
|
||||
if (w1_reset_select_slave(dev))
|
||||
return -1;
|
||||
|
||||
wrbuf[0] = W1_F2D_WRITE_SCRATCH;
|
||||
wrbuf[1] = addr & 0xff;
|
||||
wrbuf[2] = addr >> 8;
|
||||
|
||||
w1_write_block(bus, wrbuf, 3);
|
||||
w1_write_block(bus, data, len);
|
||||
|
||||
/* Read the scratchpad and verify */
|
||||
if (w1_reset_select_slave(dev))
|
||||
return -1;
|
||||
|
||||
w1_write_8(bus, W1_F2D_READ_SCRATCH);
|
||||
w1_read_block(bus, 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)) {
|
||||
|
||||
if (--tries)
|
||||
goto retry;
|
||||
|
||||
dev_err(&dev->dev,
|
||||
"could not write to eeprom, scratchpad compare failed %d times\n",
|
||||
W1_F2D_READ_RETRIES);
|
||||
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* Copy the scratchpad to EEPROM */
|
||||
if (w1_reset_select_slave(dev))
|
||||
return -1;
|
||||
|
||||
wrbuf[0] = W1_F2D_COPY_SCRATCH;
|
||||
wrbuf[3] = es;
|
||||
w1_write_block(bus, wrbuf, 4);
|
||||
|
||||
/* Sleep for tprog ms to wait for the write to complete */
|
||||
mdelay(W1_F2D_TPROG_MS);
|
||||
|
||||
/* Reset the bus to wake up the EEPROM */
|
||||
w1_reset_bus(bus);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static ssize_t ds2431_cdev_write(struct cdev *cdev, const void *buf, size_t count,
|
||||
loff_t off, ulong flags)
|
||||
{
|
||||
struct w1_device *dev = cdev->priv;
|
||||
int addr, len;
|
||||
int copy;
|
||||
|
||||
count = ds2431_fix_count(off, count, W1_F2D_EEPROM_SIZE);
|
||||
if (count == 0)
|
||||
return 0;
|
||||
|
||||
/* 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_F2D_SCRATCH_SIZE || addr & W1_F2D_SCRATCH_MASK) {
|
||||
char tmp[W1_F2D_SCRATCH_SIZE];
|
||||
|
||||
/* read the block and update the parts to be written */
|
||||
if (ds2431_readblock(dev, addr & ~W1_F2D_SCRATCH_MASK,
|
||||
W1_F2D_SCRATCH_SIZE, tmp)) {
|
||||
count = -EIO;
|
||||
goto out_up;
|
||||
}
|
||||
|
||||
/* copy at most to the boundary of the PAGE or len */
|
||||
copy = W1_F2D_SCRATCH_SIZE -
|
||||
(addr & W1_F2D_SCRATCH_MASK);
|
||||
|
||||
if (copy > len)
|
||||
copy = len;
|
||||
|
||||
memcpy(&tmp[addr & W1_F2D_SCRATCH_MASK], buf, copy);
|
||||
if (ds2431_write(dev, addr & ~W1_F2D_SCRATCH_MASK,
|
||||
W1_F2D_SCRATCH_SIZE, tmp) < 0) {
|
||||
count = -EIO;
|
||||
goto out_up;
|
||||
}
|
||||
} else {
|
||||
|
||||
copy = W1_F2D_SCRATCH_SIZE;
|
||||
if (ds2431_write(dev, addr, copy, buf) < 0) {
|
||||
count = -EIO;
|
||||
goto out_up;
|
||||
}
|
||||
}
|
||||
buf += copy;
|
||||
addr += copy;
|
||||
len -= copy;
|
||||
}
|
||||
|
||||
out_up:
|
||||
return count;
|
||||
}
|
||||
#else
|
||||
#define ds2431_cdev_write NULL
|
||||
#endif
|
||||
|
||||
static struct file_operations ds2431_ops = {
|
||||
.read = ds2431_cdev_read,
|
||||
.write = ds2431_cdev_write,
|
||||
.lseek = dev_lseek_default,
|
||||
};
|
||||
|
||||
static int ds2431_probe(struct w1_device *dev)
|
||||
{
|
||||
struct cdev *cdev;
|
||||
|
||||
cdev = xzalloc(sizeof(*cdev));
|
||||
cdev->dev = &dev->dev;
|
||||
cdev->priv = dev;
|
||||
cdev->ops = &ds2431_ops;
|
||||
cdev->size = W1_F2D_EEPROM_SIZE;
|
||||
cdev->name = asprintf(DRIVERNAME"%d", ds2431_count++);
|
||||
if (cdev->name == NULL)
|
||||
return -ENOMEM;
|
||||
|
||||
return devfs_create(cdev);
|
||||
}
|
||||
|
||||
struct w1_driver ds2431_driver = {
|
||||
.drv = {
|
||||
.name = DRIVERNAME,
|
||||
},
|
||||
.probe = ds2431_probe,
|
||||
.fid = 0x2d,
|
||||
};
|
||||
|
||||
static int w1_ds2431_init(void)
|
||||
{
|
||||
return w1_driver_register(&ds2431_driver);
|
||||
}
|
||||
device_initcall(w1_ds2431_init);
|
Loading…
Reference in New Issue