linux/drivers/w1/slaves/w1_ds2413.c
Andrew F. Davis de0d6dbdbd w1: Add subsystem kernel public interface
Like other subsystems we should be able to define slave devices outside
of the w1 directory. To do this we move public facing interface
definitions to include/linux/w1.h and rename the internal definition
file to w1_internal.h.

As w1_family.h and w1_int.h contained almost entirely public
driver interface definitions we simply removed these files and
moved the remaining definitions into w1_internal.h.

With this we can now start to move slave devices out of w1/slaves and
into the subsystem based on the function they implement, again like
other drivers.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Reviewed-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:54:54 +02:00

139 lines
3.4 KiB
C

/*
* w1_ds2413.c - w1 family 3a (DS2413) driver
* based on w1_ds2408.c by Jean-Francois Dagenais <dagenaisj@sonatest.com>
*
* Copyright (c) 2013 Mariusz Bialonczyk <manio@skyboo.net>
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
#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/w1.h>
#define W1_FAMILY_DS2413 0x3A
#define W1_F3A_RETRIES 3
#define W1_F3A_FUNC_PIO_ACCESS_READ 0xF5
#define W1_F3A_FUNC_PIO_ACCESS_WRITE 0x5A
#define W1_F3A_SUCCESS_CONFIRM_BYTE 0xAA
static ssize_t state_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);
dev_dbg(&sl->dev,
"Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p",
bin_attr->attr.name, kobj, (unsigned int)off, count, buf);
if (off != 0)
return 0;
if (!buf)
return -EINVAL;
mutex_lock(&sl->master->bus_mutex);
dev_dbg(&sl->dev, "mutex locked");
if (w1_reset_select_slave(sl)) {
mutex_unlock(&sl->master->bus_mutex);
return -EIO;
}
w1_write_8(sl->master, W1_F3A_FUNC_PIO_ACCESS_READ);
*buf = w1_read_8(sl->master);
mutex_unlock(&sl->master->bus_mutex);
dev_dbg(&sl->dev, "mutex unlocked");
/* check for correct complement */
if ((*buf & 0x0F) != ((~*buf >> 4) & 0x0F))
return -EIO;
else
return 1;
}
static BIN_ATTR_RO(state, 1);
static ssize_t output_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 w1_buf[3];
unsigned int retries = W1_F3A_RETRIES;
if (count != 1 || off != 0)
return -EFAULT;
dev_dbg(&sl->dev, "locking mutex for write_output");
mutex_lock(&sl->master->bus_mutex);
dev_dbg(&sl->dev, "mutex locked");
if (w1_reset_select_slave(sl))
goto error;
/* according to the DS2413 datasheet the most significant 6 bits
should be set to "1"s, so do it now */
*buf = *buf | 0xFC;
while (retries--) {
w1_buf[0] = W1_F3A_FUNC_PIO_ACCESS_WRITE;
w1_buf[1] = *buf;
w1_buf[2] = ~(*buf);
w1_write_block(sl->master, w1_buf, 3);
if (w1_read_8(sl->master) == W1_F3A_SUCCESS_CONFIRM_BYTE) {
mutex_unlock(&sl->master->bus_mutex);
dev_dbg(&sl->dev, "mutex unlocked, retries:%d", retries);
return 1;
}
if (w1_reset_resume_command(sl->master))
goto error;
}
error:
mutex_unlock(&sl->master->bus_mutex);
dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries);
return -EIO;
}
static BIN_ATTR(output, S_IRUGO | S_IWUSR | S_IWGRP, NULL, output_write, 1);
static struct bin_attribute *w1_f3a_bin_attrs[] = {
&bin_attr_state,
&bin_attr_output,
NULL,
};
static const struct attribute_group w1_f3a_group = {
.bin_attrs = w1_f3a_bin_attrs,
};
static const struct attribute_group *w1_f3a_groups[] = {
&w1_f3a_group,
NULL,
};
static struct w1_family_ops w1_f3a_fops = {
.groups = w1_f3a_groups,
};
static struct w1_family w1_family_3a = {
.fid = W1_FAMILY_DS2413,
.fops = &w1_f3a_fops,
};
module_w1_family(w1_family_3a);
MODULE_AUTHOR("Mariusz Bialonczyk <manio@skyboo.net>");
MODULE_DESCRIPTION("w1 family 3a driver for DS2413 2 Pin IO");
MODULE_LICENSE("GPL");
MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2413));