diff options
Diffstat (limited to 'drivers/w1/slaves/w1_ds2413.c')
| -rw-r--r-- | drivers/w1/slaves/w1_ds2413.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/drivers/w1/slaves/w1_ds2413.c b/drivers/w1/slaves/w1_ds2413.c new file mode 100644 index 00000000000..829786252c6 --- /dev/null +++ b/drivers/w1/slaves/w1_ds2413.c @@ -0,0 +1,177 @@ +/* + * 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 "../w1.h" +#include "../w1_int.h" +#include "../w1_family.h" + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Mariusz Bialonczyk <manio@skyboo.net>"); +MODULE_DESCRIPTION("w1 family 3a driver for DS2413 2 Pin IO"); + +#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 w1_f3a_read_state( + 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 ssize_t w1_f3a_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[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; +} + +#define NB_SYSFS_BIN_FILES 2 +static struct bin_attribute w1_f3a_sysfs_bin_files[NB_SYSFS_BIN_FILES] = { + { + .attr = { + .name = "state", + .mode = S_IRUGO, + }, + .size = 1, + .read = w1_f3a_read_state, + }, + { + .attr = { + .name = "output", + .mode = S_IRUGO | S_IWUSR | S_IWGRP, + }, + .size = 1, + .write = w1_f3a_write_output, + } +}; + +static int w1_f3a_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_f3a_sysfs_bin_files[i])); + if (err) + while (--i >= 0) + sysfs_remove_bin_file(&sl->dev.kobj, + &(w1_f3a_sysfs_bin_files[i])); + return err; +} + +static void w1_f3a_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_f3a_sysfs_bin_files[i])); +} + +static struct w1_family_ops w1_f3a_fops = { + .add_slave = w1_f3a_add_slave, + .remove_slave = w1_f3a_remove_slave, +}; + +static struct w1_family w1_family_3a = { + .fid = W1_FAMILY_DS2413, + .fops = &w1_f3a_fops, +}; + +static int __init w1_f3a_init(void) +{ + return w1_register_family(&w1_family_3a); +} + +static void __exit w1_f3a_exit(void) +{ + w1_unregister_family(&w1_family_3a); +} + +module_init(w1_f3a_init); +module_exit(w1_f3a_exit); |