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author | Scott Alfter <scott@alfter.us> | 2014-06-17 20:42:05 +0000 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-06-19 17:45:14 -0700 |
commit | 94859308a21b2bbf3d7c48789513c0c4a9ea7de1 (patch) | |
tree | a929e9e6f3dd3d81deeee65c6eb221c8488435a1 /drivers | |
parent | 7242d42ace30825553eabd424b41b03136d37faa (diff) | |
download | linux-stable-94859308a21b2bbf3d7c48789513c0c4a9ea7de1.tar.gz linux-stable-94859308a21b2bbf3d7c48789513c0c4a9ea7de1.tar.bz2 linux-stable-94859308a21b2bbf3d7c48789513c0c4a9ea7de1.zip |
w1: new w1_ds2406 driver
Some preliminary work at making use of this driver led me to implement
CRC-16 checks on read and write to deal with the occasional glitchiness of
the 1-Wire bus. The revised driver (attached) returns an I/O error if the
CRC check fails. When reading the chip's state, either you get a valid
indication or you get an I/O error. When changing its state, either the
change is successful or an I/O error is returned.
Signed-off-by: Scott Alfter <scott@alfter.us>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/w1/slaves/Kconfig | 7 | ||||
-rw-r--r-- | drivers/w1/slaves/Makefile | 1 | ||||
-rw-r--r-- | drivers/w1/slaves/w1_ds2406.c | 168 | ||||
-rw-r--r-- | drivers/w1/w1_family.h | 1 |
4 files changed, 177 insertions, 0 deletions
diff --git a/drivers/w1/slaves/Kconfig b/drivers/w1/slaves/Kconfig index 1cdce80b6abf..fd31d2f32c48 100644 --- a/drivers/w1/slaves/Kconfig +++ b/drivers/w1/slaves/Kconfig @@ -38,6 +38,13 @@ config W1_SLAVE_DS2413 Say Y here if you want to use a 1-wire DS2413 Dual Channel Addressable Switch device support +config W1_SLAVE_DS2406 + tristate "Dual Channel Addressable Switch 0x12 family support (DS2406)" + help + Say Y or M here if you want to use a 1-wire + DS2406 Dual Channel Addressable Switch. EPROM read/write + support for these devices is not implemented. + config W1_SLAVE_DS2423 tristate "Counter 1-wire device (DS2423)" select CRC16 diff --git a/drivers/w1/slaves/Makefile b/drivers/w1/slaves/Makefile index 06529f3157ab..1e9989afe7bf 100644 --- a/drivers/w1/slaves/Makefile +++ b/drivers/w1/slaves/Makefile @@ -6,6 +6,7 @@ obj-$(CONFIG_W1_SLAVE_THERM) += w1_therm.o obj-$(CONFIG_W1_SLAVE_SMEM) += w1_smem.o obj-$(CONFIG_W1_SLAVE_DS2408) += w1_ds2408.o obj-$(CONFIG_W1_SLAVE_DS2413) += w1_ds2413.o +obj-$(CONFIG_W1_SLAVE_DS2406) += w1_ds2406.o obj-$(CONFIG_W1_SLAVE_DS2423) += w1_ds2423.o obj-$(CONFIG_W1_SLAVE_DS2431) += w1_ds2431.o obj-$(CONFIG_W1_SLAVE_DS2433) += w1_ds2433.o diff --git a/drivers/w1/slaves/w1_ds2406.c b/drivers/w1/slaves/w1_ds2406.c new file mode 100644 index 000000000000..d488961a8c90 --- /dev/null +++ b/drivers/w1/slaves/w1_ds2406.c @@ -0,0 +1,168 @@ +/* + * w1_ds2406.c - w1 family 12 (DS2406) driver + * based on w1_ds2413.c by Mariusz Bialonczyk <manio@skyboo.net> + * + * Copyright (c) 2014 Scott Alfter <scott@alfter.us> + * + * 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/crc16.h> + +#include "../w1.h" +#include "../w1_int.h" +#include "../w1_family.h" + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Scott Alfter <scott@alfter.us>"); +MODULE_DESCRIPTION("w1 family 12 driver for DS2406 2 Pin IO"); + +#define W1_F12_FUNC_READ_STATUS 0xAA +#define W1_F12_FUNC_WRITE_STATUS 0x55 + +static ssize_t w1_f12_read_state( + struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t off, size_t count) +{ + u8 w1_buf[6]={W1_F12_FUNC_READ_STATUS, 7, 0, 0, 0, 0}; + struct w1_slave *sl = kobj_to_w1_slave(kobj); + u16 crc=0; + int i; + ssize_t rtnval=1; + + if (off != 0) + return 0; + if (!buf) + return -EINVAL; + + mutex_lock(&sl->master->bus_mutex); + + if (w1_reset_select_slave(sl)) { + mutex_unlock(&sl->master->bus_mutex); + return -EIO; + } + + w1_write_block(sl->master, w1_buf, 3); + w1_read_block(sl->master, w1_buf+3, 3); + for (i=0; i<6; i++) + crc=crc16_byte(crc, w1_buf[i]); + if (crc==0xb001) /* good read? */ + *buf=((w1_buf[3]>>5)&3)|0x30; + else + rtnval=-EIO; + + mutex_unlock(&sl->master->bus_mutex); + + return rtnval; +} + +static ssize_t w1_f12_write_output( + 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[6]={W1_F12_FUNC_WRITE_STATUS, 7, 0, 0, 0, 0}; + u16 crc=0; + int i; + ssize_t rtnval=1; + + if (count != 1 || off != 0) + return -EFAULT; + + mutex_lock(&sl->master->bus_mutex); + + if (w1_reset_select_slave(sl)) { + mutex_unlock(&sl->master->bus_mutex); + return -EIO; + } + + w1_buf[3] = (((*buf)&3)<<5)|0x1F; + w1_write_block(sl->master, w1_buf, 4); + w1_read_block(sl->master, w1_buf+4, 2); + for (i=0; i<6; i++) + crc=crc16_byte(crc, w1_buf[i]); + if (crc==0xb001) /* good read? */ + w1_write_8(sl->master, 0xFF); + else + rtnval=-EIO; + + mutex_unlock(&sl->master->bus_mutex); + return rtnval; +} + +#define NB_SYSFS_BIN_FILES 2 +static struct bin_attribute w1_f12_sysfs_bin_files[NB_SYSFS_BIN_FILES] = { + { + .attr = { + .name = "state", + .mode = S_IRUGO, + }, + .size = 1, + .read = w1_f12_read_state, + }, + { + .attr = { + .name = "output", + .mode = S_IRUGO | S_IWUSR | S_IWGRP, + }, + .size = 1, + .write = w1_f12_write_output, + } +}; + +static int w1_f12_add_slave(struct w1_slave *sl) +{ + int err = 0; + int i; + + for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i) + err = sysfs_create_bin_file( + &sl->dev.kobj, + &(w1_f12_sysfs_bin_files[i])); + if (err) + while (--i >= 0) + sysfs_remove_bin_file(&sl->dev.kobj, + &(w1_f12_sysfs_bin_files[i])); + return err; +} + +static void w1_f12_remove_slave(struct w1_slave *sl) +{ + int i; + for (i = NB_SYSFS_BIN_FILES - 1; i >= 0; --i) + sysfs_remove_bin_file(&sl->dev.kobj, + &(w1_f12_sysfs_bin_files[i])); +} + +static struct w1_family_ops w1_f12_fops = { + .add_slave = w1_f12_add_slave, + .remove_slave = w1_f12_remove_slave, +}; + +static struct w1_family w1_family_12 = { + .fid = W1_FAMILY_DS2406, + .fops = &w1_f12_fops, +}; + +static int __init w1_f12_init(void) +{ + return w1_register_family(&w1_family_12); +} + +static void __exit w1_f12_exit(void) +{ + w1_unregister_family(&w1_family_12); +} + +module_init(w1_f12_init); +module_exit(w1_f12_exit); diff --git a/drivers/w1/w1_family.h b/drivers/w1/w1_family.h index 26ca1343055b..0d18365b61ad 100644 --- a/drivers/w1/w1_family.h +++ b/drivers/w1/w1_family.h @@ -40,6 +40,7 @@ #define W1_FAMILY_DS2760 0x30 #define W1_FAMILY_DS2780 0x32 #define W1_FAMILY_DS2413 0x3A +#define W1_FAMILY_DS2406 0x12 #define W1_THERM_DS1825 0x3B #define W1_FAMILY_DS2781 0x3D #define W1_THERM_DS28EA00 0x42 |