diff options
Diffstat (limited to 'drivers/w1/slaves/w1_ds2413.c')
| -rw-r--r-- | drivers/w1/slaves/w1_ds2413.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/drivers/w1/slaves/w1_ds2413.c b/drivers/w1/slaves/w1_ds2413.c new file mode 100644 index 000000000..c8cfac555 --- /dev/null +++ b/drivers/w1/slaves/w1_ds2413.c @@ -0,0 +1,159 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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> + */ + +#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 +#define W1_F3A_INVALID_PIO_STATE 0xFF + +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); + unsigned int retries = W1_F3A_RETRIES; + ssize_t bytes_read = -EIO; + u8 state; + + 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"); + +next: + if (w1_reset_select_slave(sl)) + goto out; + + while (retries--) { + w1_write_8(sl->master, W1_F3A_FUNC_PIO_ACCESS_READ); + + state = w1_read_8(sl->master); + if ((state & 0x0F) == ((~state >> 4) & 0x0F)) { + /* complement is correct */ + *buf = state; + bytes_read = 1; + goto out; + } else if (state == W1_F3A_INVALID_PIO_STATE) { + /* slave didn't respond, try to select it again */ + dev_warn(&sl->dev, "slave device did not respond to PIO_ACCESS_READ, " \ + "reselecting, retries left: %d\n", retries); + goto next; + } + + if (w1_reset_resume_command(sl->master)) + goto out; /* unrecoverable error */ + + dev_warn(&sl->dev, "PIO_ACCESS_READ error, retries left: %d\n", retries); + } + +out: + mutex_unlock(&sl->master->bus_mutex); + dev_dbg(&sl->dev, "%s, mutex unlocked, retries: %d\n", + (bytes_read > 0) ? "succeeded" : "error", retries); + return bytes_read; +} + +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; + ssize_t bytes_written = -EIO; + + 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 out; + + /* 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) { + bytes_written = 1; + goto out; + } + if (w1_reset_resume_command(sl->master)) + goto out; /* unrecoverable error */ + + dev_warn(&sl->dev, "PIO_ACCESS_WRITE error, retries left: %d\n", retries); + } + +out: + mutex_unlock(&sl->master->bus_mutex); + dev_dbg(&sl->dev, "%s, mutex unlocked, retries: %d\n", + (bytes_written > 0) ? "succeeded" : "error", retries); + return bytes_written; +} + +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 const 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)); |