diff options
Diffstat (limited to 'drivers/w1/slaves/w1_ds2406.c')
| -rw-r--r-- | drivers/w1/slaves/w1_ds2406.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/drivers/w1/slaves/w1_ds2406.c b/drivers/w1/slaves/w1_ds2406.c new file mode 100644 index 000000000..2f5926859 --- /dev/null +++ b/drivers/w1/slaves/w1_ds2406.c @@ -0,0 +1,155 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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> + */ + +#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/w1.h> + +#define W1_FAMILY_DS2406 0x12 + +#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 = 0444, + }, + .size = 1, + .read = w1_f12_read_state, + }, + { + .attr = { + .name = "output", + .mode = 0664, + }, + .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 const 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, +}; +module_w1_family(w1_family_12); + +MODULE_AUTHOR("Scott Alfter <scott@alfter.us>"); +MODULE_DESCRIPTION("w1 family 12 driver for DS2406 2 Pin IO"); +MODULE_LICENSE("GPL"); |