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1280 lines
32 KiB
1280 lines
32 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Copyright (c) 2004 Evgeniy Polyakov <[email protected]> |
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*/ |
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|
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#include <linux/delay.h> |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/moduleparam.h> |
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#include <linux/list.h> |
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#include <linux/interrupt.h> |
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#include <linux/spinlock.h> |
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#include <linux/timer.h> |
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#include <linux/device.h> |
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#include <linux/slab.h> |
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#include <linux/sched.h> |
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#include <linux/kthread.h> |
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#include <linux/freezer.h> |
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#include <linux/hwmon.h> |
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#include <linux/of.h> |
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#include <linux/atomic.h> |
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|
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#include "w1_internal.h" |
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#include "w1_netlink.h" |
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#define W1_FAMILY_DEFAULT 0 |
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#define W1_FAMILY_DS28E04 0x1C /* for crc quirk */ |
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static int w1_timeout = 10; |
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module_param_named(timeout, w1_timeout, int, 0); |
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MODULE_PARM_DESC(timeout, "time in seconds between automatic slave searches"); |
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static int w1_timeout_us = 0; |
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module_param_named(timeout_us, w1_timeout_us, int, 0); |
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MODULE_PARM_DESC(timeout_us, |
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"time in microseconds between automatic slave searches"); |
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|
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/* A search stops when w1_max_slave_count devices have been found in that |
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* search. The next search will start over and detect the same set of devices |
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* on a static 1-wire bus. Memory is not allocated based on this number, just |
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* on the number of devices known to the kernel. Having a high number does not |
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* consume additional resources. As a special case, if there is only one |
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* device on the network and w1_max_slave_count is set to 1, the device id can |
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* be read directly skipping the normal slower search process. |
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*/ |
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int w1_max_slave_count = 64; |
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module_param_named(max_slave_count, w1_max_slave_count, int, 0); |
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MODULE_PARM_DESC(max_slave_count, |
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"maximum number of slaves detected in a search"); |
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|
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int w1_max_slave_ttl = 10; |
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module_param_named(slave_ttl, w1_max_slave_ttl, int, 0); |
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MODULE_PARM_DESC(slave_ttl, |
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"Number of searches not seeing a slave before it will be removed"); |
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DEFINE_MUTEX(w1_mlock); |
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LIST_HEAD(w1_masters); |
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static int w1_master_match(struct device *dev, struct device_driver *drv) |
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{ |
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return 1; |
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} |
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static int w1_master_probe(struct device *dev) |
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{ |
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return -ENODEV; |
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} |
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static void w1_master_release(struct device *dev) |
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{ |
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struct w1_master *md = dev_to_w1_master(dev); |
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dev_dbg(dev, "%s: Releasing %s.\n", __func__, md->name); |
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memset(md, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master)); |
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kfree(md); |
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} |
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static void w1_slave_release(struct device *dev) |
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{ |
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struct w1_slave *sl = dev_to_w1_slave(dev); |
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dev_dbg(dev, "%s: Releasing %s [%p]\n", __func__, sl->name, sl); |
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w1_family_put(sl->family); |
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sl->master->slave_count--; |
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} |
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static ssize_t name_show(struct device *dev, struct device_attribute *attr, char *buf) |
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{ |
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struct w1_slave *sl = dev_to_w1_slave(dev); |
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return sprintf(buf, "%s\n", sl->name); |
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} |
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static DEVICE_ATTR_RO(name); |
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static ssize_t id_show(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct w1_slave *sl = dev_to_w1_slave(dev); |
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ssize_t count = sizeof(sl->reg_num); |
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memcpy(buf, (u8 *)&sl->reg_num, count); |
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return count; |
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} |
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static DEVICE_ATTR_RO(id); |
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static struct attribute *w1_slave_attrs[] = { |
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&dev_attr_name.attr, |
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&dev_attr_id.attr, |
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NULL, |
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}; |
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ATTRIBUTE_GROUPS(w1_slave); |
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|
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/* Default family */ |
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static ssize_t rw_write(struct file *filp, struct kobject *kobj, |
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struct bin_attribute *bin_attr, char *buf, loff_t off, |
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size_t count) |
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{ |
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struct w1_slave *sl = kobj_to_w1_slave(kobj); |
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mutex_lock(&sl->master->mutex); |
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if (w1_reset_select_slave(sl)) { |
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count = 0; |
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goto out_up; |
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} |
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w1_write_block(sl->master, buf, count); |
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out_up: |
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mutex_unlock(&sl->master->mutex); |
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return count; |
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} |
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static ssize_t rw_read(struct file *filp, struct kobject *kobj, |
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struct bin_attribute *bin_attr, char *buf, loff_t off, |
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size_t count) |
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{ |
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struct w1_slave *sl = kobj_to_w1_slave(kobj); |
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mutex_lock(&sl->master->mutex); |
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w1_read_block(sl->master, buf, count); |
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mutex_unlock(&sl->master->mutex); |
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return count; |
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} |
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static BIN_ATTR_RW(rw, PAGE_SIZE); |
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static struct bin_attribute *w1_slave_bin_attrs[] = { |
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&bin_attr_rw, |
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NULL, |
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}; |
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static const struct attribute_group w1_slave_default_group = { |
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.bin_attrs = w1_slave_bin_attrs, |
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}; |
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static const struct attribute_group *w1_slave_default_groups[] = { |
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&w1_slave_default_group, |
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NULL, |
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}; |
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static const struct w1_family_ops w1_default_fops = { |
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.groups = w1_slave_default_groups, |
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}; |
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static struct w1_family w1_default_family = { |
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.fops = &w1_default_fops, |
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}; |
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static int w1_uevent(struct device *dev, struct kobj_uevent_env *env); |
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static struct bus_type w1_bus_type = { |
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.name = "w1", |
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.match = w1_master_match, |
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.uevent = w1_uevent, |
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}; |
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struct device_driver w1_master_driver = { |
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.name = "w1_master_driver", |
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.bus = &w1_bus_type, |
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.probe = w1_master_probe, |
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}; |
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struct device w1_master_device = { |
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.parent = NULL, |
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.bus = &w1_bus_type, |
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.init_name = "w1 bus master", |
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.driver = &w1_master_driver, |
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.release = &w1_master_release |
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}; |
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static struct device_driver w1_slave_driver = { |
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.name = "w1_slave_driver", |
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.bus = &w1_bus_type, |
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}; |
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#if 0 |
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struct device w1_slave_device = { |
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.parent = NULL, |
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.bus = &w1_bus_type, |
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.init_name = "w1 bus slave", |
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.driver = &w1_slave_driver, |
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.release = &w1_slave_release |
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}; |
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#endif /* 0 */ |
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static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf) |
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{ |
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struct w1_master *md = dev_to_w1_master(dev); |
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ssize_t count; |
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mutex_lock(&md->mutex); |
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count = sprintf(buf, "%s\n", md->name); |
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mutex_unlock(&md->mutex); |
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return count; |
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} |
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static ssize_t w1_master_attribute_store_search(struct device * dev, |
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struct device_attribute *attr, |
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const char * buf, size_t count) |
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{ |
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long tmp; |
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struct w1_master *md = dev_to_w1_master(dev); |
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int ret; |
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ret = kstrtol(buf, 0, &tmp); |
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if (ret) |
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return ret; |
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mutex_lock(&md->mutex); |
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md->search_count = tmp; |
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mutex_unlock(&md->mutex); |
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/* Only wake if it is going to be searching. */ |
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if (tmp) |
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wake_up_process(md->thread); |
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return count; |
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} |
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static ssize_t w1_master_attribute_show_search(struct device *dev, |
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struct device_attribute *attr, |
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char *buf) |
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{ |
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struct w1_master *md = dev_to_w1_master(dev); |
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ssize_t count; |
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mutex_lock(&md->mutex); |
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count = sprintf(buf, "%d\n", md->search_count); |
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mutex_unlock(&md->mutex); |
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return count; |
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} |
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static ssize_t w1_master_attribute_store_pullup(struct device *dev, |
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struct device_attribute *attr, |
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const char *buf, size_t count) |
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{ |
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long tmp; |
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struct w1_master *md = dev_to_w1_master(dev); |
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int ret; |
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ret = kstrtol(buf, 0, &tmp); |
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if (ret) |
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return ret; |
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mutex_lock(&md->mutex); |
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md->enable_pullup = tmp; |
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mutex_unlock(&md->mutex); |
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return count; |
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} |
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static ssize_t w1_master_attribute_show_pullup(struct device *dev, |
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struct device_attribute *attr, |
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char *buf) |
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{ |
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struct w1_master *md = dev_to_w1_master(dev); |
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ssize_t count; |
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mutex_lock(&md->mutex); |
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count = sprintf(buf, "%d\n", md->enable_pullup); |
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mutex_unlock(&md->mutex); |
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return count; |
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} |
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static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf) |
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{ |
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struct w1_master *md = dev_to_w1_master(dev); |
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ssize_t count; |
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mutex_lock(&md->mutex); |
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count = sprintf(buf, "0x%p\n", md->bus_master); |
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mutex_unlock(&md->mutex); |
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return count; |
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} |
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static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf) |
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{ |
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ssize_t count; |
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count = sprintf(buf, "%d\n", w1_timeout); |
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return count; |
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} |
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static ssize_t w1_master_attribute_show_timeout_us(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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ssize_t count; |
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count = sprintf(buf, "%d\n", w1_timeout_us); |
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return count; |
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} |
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static ssize_t w1_master_attribute_store_max_slave_count(struct device *dev, |
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struct device_attribute *attr, const char *buf, size_t count) |
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{ |
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int tmp; |
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struct w1_master *md = dev_to_w1_master(dev); |
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if (kstrtoint(buf, 0, &tmp) || tmp < 1) |
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return -EINVAL; |
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mutex_lock(&md->mutex); |
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md->max_slave_count = tmp; |
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/* allow each time the max_slave_count is updated */ |
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clear_bit(W1_WARN_MAX_COUNT, &md->flags); |
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mutex_unlock(&md->mutex); |
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return count; |
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} |
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static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf) |
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{ |
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struct w1_master *md = dev_to_w1_master(dev); |
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ssize_t count; |
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mutex_lock(&md->mutex); |
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count = sprintf(buf, "%d\n", md->max_slave_count); |
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mutex_unlock(&md->mutex); |
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return count; |
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} |
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static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf) |
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{ |
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struct w1_master *md = dev_to_w1_master(dev); |
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ssize_t count; |
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mutex_lock(&md->mutex); |
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count = sprintf(buf, "%lu\n", md->attempts); |
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mutex_unlock(&md->mutex); |
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return count; |
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} |
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static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf) |
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{ |
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struct w1_master *md = dev_to_w1_master(dev); |
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ssize_t count; |
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mutex_lock(&md->mutex); |
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count = sprintf(buf, "%d\n", md->slave_count); |
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mutex_unlock(&md->mutex); |
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return count; |
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} |
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static ssize_t w1_master_attribute_show_slaves(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct w1_master *md = dev_to_w1_master(dev); |
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int c = PAGE_SIZE; |
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struct list_head *ent, *n; |
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struct w1_slave *sl = NULL; |
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mutex_lock(&md->list_mutex); |
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list_for_each_safe(ent, n, &md->slist) { |
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sl = list_entry(ent, struct w1_slave, w1_slave_entry); |
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c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name); |
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} |
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if (!sl) |
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c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n"); |
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mutex_unlock(&md->list_mutex); |
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return PAGE_SIZE - c; |
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} |
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static ssize_t w1_master_attribute_show_add(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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int c = PAGE_SIZE; |
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c -= snprintf(buf+PAGE_SIZE - c, c, |
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"write device id xx-xxxxxxxxxxxx to add slave\n"); |
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return PAGE_SIZE - c; |
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} |
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static int w1_atoreg_num(struct device *dev, const char *buf, size_t count, |
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struct w1_reg_num *rn) |
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{ |
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unsigned int family; |
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unsigned long long id; |
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int i; |
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u64 rn64_le; |
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/* The CRC value isn't read from the user because the sysfs directory |
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* doesn't include it and most messages from the bus search don't |
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* print it either. It would be unreasonable for the user to then |
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* provide it. |
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*/ |
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const char *error_msg = "bad slave string format, expecting " |
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"ff-dddddddddddd\n"; |
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if (buf[2] != '-') { |
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dev_err(dev, "%s", error_msg); |
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return -EINVAL; |
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} |
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i = sscanf(buf, "%02x-%012llx", &family, &id); |
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if (i != 2) { |
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dev_err(dev, "%s", error_msg); |
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return -EINVAL; |
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} |
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rn->family = family; |
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rn->id = id; |
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rn64_le = cpu_to_le64(*(u64 *)rn); |
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rn->crc = w1_calc_crc8((u8 *)&rn64_le, 7); |
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#if 0 |
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dev_info(dev, "With CRC device is %02x.%012llx.%02x.\n", |
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rn->family, (unsigned long long)rn->id, rn->crc); |
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#endif |
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return 0; |
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} |
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/* Searches the slaves in the w1_master and returns a pointer or NULL. |
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* Note: must not hold list_mutex |
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*/ |
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struct w1_slave *w1_slave_search_device(struct w1_master *dev, |
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struct w1_reg_num *rn) |
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{ |
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struct w1_slave *sl; |
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mutex_lock(&dev->list_mutex); |
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list_for_each_entry(sl, &dev->slist, w1_slave_entry) { |
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if (sl->reg_num.family == rn->family && |
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sl->reg_num.id == rn->id && |
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sl->reg_num.crc == rn->crc) { |
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mutex_unlock(&dev->list_mutex); |
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return sl; |
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} |
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} |
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mutex_unlock(&dev->list_mutex); |
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return NULL; |
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} |
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static ssize_t w1_master_attribute_store_add(struct device *dev, |
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struct device_attribute *attr, |
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const char *buf, size_t count) |
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{ |
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struct w1_master *md = dev_to_w1_master(dev); |
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struct w1_reg_num rn; |
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struct w1_slave *sl; |
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ssize_t result = count; |
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if (w1_atoreg_num(dev, buf, count, &rn)) |
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return -EINVAL; |
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mutex_lock(&md->mutex); |
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sl = w1_slave_search_device(md, &rn); |
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/* It would be nice to do a targeted search one the one-wire bus |
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* for the new device to see if it is out there or not. But the |
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* current search doesn't support that. |
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*/ |
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if (sl) { |
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dev_info(dev, "Device %s already exists\n", sl->name); |
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result = -EINVAL; |
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} else { |
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w1_attach_slave_device(md, &rn); |
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} |
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mutex_unlock(&md->mutex); |
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return result; |
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} |
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static ssize_t w1_master_attribute_show_remove(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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int c = PAGE_SIZE; |
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c -= snprintf(buf+PAGE_SIZE - c, c, |
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"write device id xx-xxxxxxxxxxxx to remove slave\n"); |
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return PAGE_SIZE - c; |
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} |
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static ssize_t w1_master_attribute_store_remove(struct device *dev, |
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struct device_attribute *attr, |
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const char *buf, size_t count) |
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{ |
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struct w1_master *md = dev_to_w1_master(dev); |
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struct w1_reg_num rn; |
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struct w1_slave *sl; |
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ssize_t result = count; |
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|
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if (w1_atoreg_num(dev, buf, count, &rn)) |
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return -EINVAL; |
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mutex_lock(&md->mutex); |
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sl = w1_slave_search_device(md, &rn); |
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if (sl) { |
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result = w1_slave_detach(sl); |
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/* refcnt 0 means it was detached in the call */ |
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if (result == 0) |
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result = count; |
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} else { |
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dev_info(dev, "Device %02x-%012llx doesn't exists\n", rn.family, |
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(unsigned long long)rn.id); |
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result = -EINVAL; |
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} |
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mutex_unlock(&md->mutex); |
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|
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return result; |
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} |
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|
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#define W1_MASTER_ATTR_RO(_name, _mode) \ |
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struct device_attribute w1_master_attribute_##_name = \ |
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__ATTR(w1_master_##_name, _mode, \ |
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w1_master_attribute_show_##_name, NULL) |
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|
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#define W1_MASTER_ATTR_RW(_name, _mode) \ |
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struct device_attribute w1_master_attribute_##_name = \ |
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__ATTR(w1_master_##_name, _mode, \ |
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w1_master_attribute_show_##_name, \ |
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w1_master_attribute_store_##_name) |
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|
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static W1_MASTER_ATTR_RO(name, S_IRUGO); |
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static W1_MASTER_ATTR_RO(slaves, S_IRUGO); |
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static W1_MASTER_ATTR_RO(slave_count, S_IRUGO); |
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static W1_MASTER_ATTR_RW(max_slave_count, S_IRUGO | S_IWUSR | S_IWGRP); |
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static W1_MASTER_ATTR_RO(attempts, S_IRUGO); |
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static W1_MASTER_ATTR_RO(timeout, S_IRUGO); |
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static W1_MASTER_ATTR_RO(timeout_us, S_IRUGO); |
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static W1_MASTER_ATTR_RO(pointer, S_IRUGO); |
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static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUSR | S_IWGRP); |
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static W1_MASTER_ATTR_RW(pullup, S_IRUGO | S_IWUSR | S_IWGRP); |
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static W1_MASTER_ATTR_RW(add, S_IRUGO | S_IWUSR | S_IWGRP); |
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static W1_MASTER_ATTR_RW(remove, S_IRUGO | S_IWUSR | S_IWGRP); |
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|
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static struct attribute *w1_master_default_attrs[] = { |
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&w1_master_attribute_name.attr, |
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&w1_master_attribute_slaves.attr, |
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&w1_master_attribute_slave_count.attr, |
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&w1_master_attribute_max_slave_count.attr, |
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&w1_master_attribute_attempts.attr, |
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&w1_master_attribute_timeout.attr, |
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&w1_master_attribute_timeout_us.attr, |
|
&w1_master_attribute_pointer.attr, |
|
&w1_master_attribute_search.attr, |
|
&w1_master_attribute_pullup.attr, |
|
&w1_master_attribute_add.attr, |
|
&w1_master_attribute_remove.attr, |
|
NULL |
|
}; |
|
|
|
static const struct attribute_group w1_master_defattr_group = { |
|
.attrs = w1_master_default_attrs, |
|
}; |
|
|
|
int w1_create_master_attributes(struct w1_master *master) |
|
{ |
|
return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group); |
|
} |
|
|
|
void w1_destroy_master_attributes(struct w1_master *master) |
|
{ |
|
sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group); |
|
} |
|
|
|
static int w1_uevent(struct device *dev, struct kobj_uevent_env *env) |
|
{ |
|
struct w1_master *md = NULL; |
|
struct w1_slave *sl = NULL; |
|
char *event_owner, *name; |
|
int err = 0; |
|
|
|
if (dev->driver == &w1_master_driver) { |
|
md = container_of(dev, struct w1_master, dev); |
|
event_owner = "master"; |
|
name = md->name; |
|
} else if (dev->driver == &w1_slave_driver) { |
|
sl = container_of(dev, struct w1_slave, dev); |
|
event_owner = "slave"; |
|
name = sl->name; |
|
} else { |
|
dev_dbg(dev, "Unknown event.\n"); |
|
return -EINVAL; |
|
} |
|
|
|
dev_dbg(dev, "Hotplug event for %s %s, bus_id=%s.\n", |
|
event_owner, name, dev_name(dev)); |
|
|
|
if (dev->driver != &w1_slave_driver || !sl) |
|
goto end; |
|
|
|
err = add_uevent_var(env, "W1_FID=%02X", sl->reg_num.family); |
|
if (err) |
|
goto end; |
|
|
|
err = add_uevent_var(env, "W1_SLAVE_ID=%024LX", |
|
(unsigned long long)sl->reg_num.id); |
|
end: |
|
return err; |
|
} |
|
|
|
static int w1_family_notify(unsigned long action, struct w1_slave *sl) |
|
{ |
|
const struct w1_family_ops *fops; |
|
int err; |
|
|
|
fops = sl->family->fops; |
|
|
|
if (!fops) |
|
return 0; |
|
|
|
switch (action) { |
|
case BUS_NOTIFY_ADD_DEVICE: |
|
/* if the family driver needs to initialize something... */ |
|
if (fops->add_slave) { |
|
err = fops->add_slave(sl); |
|
if (err < 0) { |
|
dev_err(&sl->dev, |
|
"add_slave() call failed. err=%d\n", |
|
err); |
|
return err; |
|
} |
|
} |
|
if (fops->groups) { |
|
err = sysfs_create_groups(&sl->dev.kobj, fops->groups); |
|
if (err) { |
|
dev_err(&sl->dev, |
|
"sysfs group creation failed. err=%d\n", |
|
err); |
|
return err; |
|
} |
|
} |
|
if (IS_REACHABLE(CONFIG_HWMON) && fops->chip_info) { |
|
struct device *hwmon |
|
= hwmon_device_register_with_info(&sl->dev, |
|
"w1_slave_temp", sl, |
|
fops->chip_info, |
|
NULL); |
|
if (IS_ERR(hwmon)) { |
|
dev_warn(&sl->dev, |
|
"could not create hwmon device\n"); |
|
} else { |
|
sl->hwmon = hwmon; |
|
} |
|
} |
|
break; |
|
case BUS_NOTIFY_DEL_DEVICE: |
|
if (IS_REACHABLE(CONFIG_HWMON) && fops->chip_info && |
|
sl->hwmon) |
|
hwmon_device_unregister(sl->hwmon); |
|
if (fops->remove_slave) |
|
sl->family->fops->remove_slave(sl); |
|
if (fops->groups) |
|
sysfs_remove_groups(&sl->dev.kobj, fops->groups); |
|
break; |
|
} |
|
return 0; |
|
} |
|
|
|
static int __w1_attach_slave_device(struct w1_slave *sl) |
|
{ |
|
int err; |
|
|
|
sl->dev.parent = &sl->master->dev; |
|
sl->dev.driver = &w1_slave_driver; |
|
sl->dev.bus = &w1_bus_type; |
|
sl->dev.release = &w1_slave_release; |
|
sl->dev.groups = w1_slave_groups; |
|
sl->dev.of_node = of_find_matching_node(sl->master->dev.of_node, |
|
sl->family->of_match_table); |
|
|
|
dev_set_name(&sl->dev, "%02x-%012llx", |
|
(unsigned int) sl->reg_num.family, |
|
(unsigned long long) sl->reg_num.id); |
|
snprintf(&sl->name[0], sizeof(sl->name), |
|
"%02x-%012llx", |
|
(unsigned int) sl->reg_num.family, |
|
(unsigned long long) sl->reg_num.id); |
|
|
|
dev_dbg(&sl->dev, "%s: registering %s as %p.\n", __func__, |
|
dev_name(&sl->dev), sl); |
|
|
|
/* suppress for w1_family_notify before sending KOBJ_ADD */ |
|
dev_set_uevent_suppress(&sl->dev, true); |
|
|
|
err = device_register(&sl->dev); |
|
if (err < 0) { |
|
dev_err(&sl->dev, |
|
"Device registration [%s] failed. err=%d\n", |
|
dev_name(&sl->dev), err); |
|
put_device(&sl->dev); |
|
return err; |
|
} |
|
w1_family_notify(BUS_NOTIFY_ADD_DEVICE, sl); |
|
|
|
dev_set_uevent_suppress(&sl->dev, false); |
|
kobject_uevent(&sl->dev.kobj, KOBJ_ADD); |
|
|
|
mutex_lock(&sl->master->list_mutex); |
|
list_add_tail(&sl->w1_slave_entry, &sl->master->slist); |
|
mutex_unlock(&sl->master->list_mutex); |
|
|
|
return 0; |
|
} |
|
|
|
int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn) |
|
{ |
|
struct w1_slave *sl; |
|
struct w1_family *f; |
|
int err; |
|
struct w1_netlink_msg msg; |
|
|
|
sl = kzalloc(sizeof(struct w1_slave), GFP_KERNEL); |
|
if (!sl) { |
|
dev_err(&dev->dev, |
|
"%s: failed to allocate new slave device.\n", |
|
__func__); |
|
return -ENOMEM; |
|
} |
|
|
|
|
|
sl->owner = THIS_MODULE; |
|
sl->master = dev; |
|
set_bit(W1_SLAVE_ACTIVE, &sl->flags); |
|
|
|
memset(&msg, 0, sizeof(msg)); |
|
memcpy(&sl->reg_num, rn, sizeof(sl->reg_num)); |
|
atomic_set(&sl->refcnt, 1); |
|
atomic_inc(&sl->master->refcnt); |
|
dev->slave_count++; |
|
dev_info(&dev->dev, "Attaching one wire slave %02x.%012llx crc %02x\n", |
|
rn->family, (unsigned long long)rn->id, rn->crc); |
|
|
|
/* slave modules need to be loaded in a context with unlocked mutex */ |
|
mutex_unlock(&dev->mutex); |
|
request_module("w1-family-0x%02X", rn->family); |
|
mutex_lock(&dev->mutex); |
|
|
|
spin_lock(&w1_flock); |
|
f = w1_family_registered(rn->family); |
|
if (!f) { |
|
f= &w1_default_family; |
|
dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n", |
|
rn->family, rn->family, |
|
(unsigned long long)rn->id, rn->crc); |
|
} |
|
__w1_family_get(f); |
|
spin_unlock(&w1_flock); |
|
|
|
sl->family = f; |
|
|
|
err = __w1_attach_slave_device(sl); |
|
if (err < 0) { |
|
dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__, |
|
sl->name); |
|
dev->slave_count--; |
|
w1_family_put(sl->family); |
|
atomic_dec(&sl->master->refcnt); |
|
kfree(sl); |
|
return err; |
|
} |
|
|
|
sl->ttl = dev->slave_ttl; |
|
|
|
memcpy(msg.id.id, rn, sizeof(msg.id)); |
|
msg.type = W1_SLAVE_ADD; |
|
w1_netlink_send(dev, &msg); |
|
|
|
return 0; |
|
} |
|
|
|
int w1_unref_slave(struct w1_slave *sl) |
|
{ |
|
struct w1_master *dev = sl->master; |
|
int refcnt; |
|
mutex_lock(&dev->list_mutex); |
|
refcnt = atomic_sub_return(1, &sl->refcnt); |
|
if (refcnt == 0) { |
|
struct w1_netlink_msg msg; |
|
|
|
dev_dbg(&sl->dev, "%s: detaching %s [%p].\n", __func__, |
|
sl->name, sl); |
|
|
|
list_del(&sl->w1_slave_entry); |
|
|
|
memset(&msg, 0, sizeof(msg)); |
|
memcpy(msg.id.id, &sl->reg_num, sizeof(msg.id)); |
|
msg.type = W1_SLAVE_REMOVE; |
|
w1_netlink_send(sl->master, &msg); |
|
|
|
w1_family_notify(BUS_NOTIFY_DEL_DEVICE, sl); |
|
device_unregister(&sl->dev); |
|
#ifdef DEBUG |
|
memset(sl, 0, sizeof(*sl)); |
|
#endif |
|
kfree(sl); |
|
} |
|
atomic_dec(&dev->refcnt); |
|
mutex_unlock(&dev->list_mutex); |
|
return refcnt; |
|
} |
|
|
|
int w1_slave_detach(struct w1_slave *sl) |
|
{ |
|
/* Only detach a slave once as it decreases the refcnt each time. */ |
|
int destroy_now; |
|
mutex_lock(&sl->master->list_mutex); |
|
destroy_now = !test_bit(W1_SLAVE_DETACH, &sl->flags); |
|
set_bit(W1_SLAVE_DETACH, &sl->flags); |
|
mutex_unlock(&sl->master->list_mutex); |
|
|
|
if (destroy_now) |
|
destroy_now = !w1_unref_slave(sl); |
|
return destroy_now ? 0 : -EBUSY; |
|
} |
|
|
|
struct w1_master *w1_search_master_id(u32 id) |
|
{ |
|
struct w1_master *dev; |
|
int found = 0; |
|
|
|
mutex_lock(&w1_mlock); |
|
list_for_each_entry(dev, &w1_masters, w1_master_entry) { |
|
if (dev->id == id) { |
|
found = 1; |
|
atomic_inc(&dev->refcnt); |
|
break; |
|
} |
|
} |
|
mutex_unlock(&w1_mlock); |
|
|
|
return (found)?dev:NULL; |
|
} |
|
|
|
struct w1_slave *w1_search_slave(struct w1_reg_num *id) |
|
{ |
|
struct w1_master *dev; |
|
struct w1_slave *sl = NULL; |
|
int found = 0; |
|
|
|
mutex_lock(&w1_mlock); |
|
list_for_each_entry(dev, &w1_masters, w1_master_entry) { |
|
mutex_lock(&dev->list_mutex); |
|
list_for_each_entry(sl, &dev->slist, w1_slave_entry) { |
|
if (sl->reg_num.family == id->family && |
|
sl->reg_num.id == id->id && |
|
sl->reg_num.crc == id->crc) { |
|
found = 1; |
|
atomic_inc(&dev->refcnt); |
|
atomic_inc(&sl->refcnt); |
|
break; |
|
} |
|
} |
|
mutex_unlock(&dev->list_mutex); |
|
|
|
if (found) |
|
break; |
|
} |
|
mutex_unlock(&w1_mlock); |
|
|
|
return (found)?sl:NULL; |
|
} |
|
|
|
void w1_reconnect_slaves(struct w1_family *f, int attach) |
|
{ |
|
struct w1_slave *sl, *sln; |
|
struct w1_master *dev; |
|
|
|
mutex_lock(&w1_mlock); |
|
list_for_each_entry(dev, &w1_masters, w1_master_entry) { |
|
dev_dbg(&dev->dev, "Reconnecting slaves in device %s " |
|
"for family %02x.\n", dev->name, f->fid); |
|
mutex_lock(&dev->mutex); |
|
mutex_lock(&dev->list_mutex); |
|
list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) { |
|
/* If it is a new family, slaves with the default |
|
* family driver and are that family will be |
|
* connected. If the family is going away, devices |
|
* matching that family are reconneced. |
|
*/ |
|
if ((attach && sl->family->fid == W1_FAMILY_DEFAULT |
|
&& sl->reg_num.family == f->fid) || |
|
(!attach && sl->family->fid == f->fid)) { |
|
struct w1_reg_num rn; |
|
|
|
mutex_unlock(&dev->list_mutex); |
|
memcpy(&rn, &sl->reg_num, sizeof(rn)); |
|
/* If it was already in use let the automatic |
|
* scan pick it up again later. |
|
*/ |
|
if (!w1_slave_detach(sl)) |
|
w1_attach_slave_device(dev, &rn); |
|
mutex_lock(&dev->list_mutex); |
|
} |
|
} |
|
dev_dbg(&dev->dev, "Reconnecting slaves in device %s " |
|
"has been finished.\n", dev->name); |
|
mutex_unlock(&dev->list_mutex); |
|
mutex_unlock(&dev->mutex); |
|
} |
|
mutex_unlock(&w1_mlock); |
|
} |
|
|
|
static int w1_addr_crc_is_valid(struct w1_master *dev, u64 rn) |
|
{ |
|
u64 rn_le = cpu_to_le64(rn); |
|
struct w1_reg_num *tmp = (struct w1_reg_num *)&rn; |
|
u8 crc; |
|
|
|
crc = w1_calc_crc8((u8 *)&rn_le, 7); |
|
|
|
/* quirk: |
|
* DS28E04 (1w eeprom) has strapping pins to change |
|
* address, but will not update the crc. So normal rules |
|
* for consistent w1 addresses are violated. We test |
|
* with the 7 LSBs of the address forced high. |
|
* |
|
* (char*)&rn_le = { family, addr_lsb, ..., addr_msb, crc }. |
|
*/ |
|
if (crc != tmp->crc && tmp->family == W1_FAMILY_DS28E04) { |
|
u64 corr_le = rn_le; |
|
|
|
((u8 *)&corr_le)[1] |= 0x7f; |
|
crc = w1_calc_crc8((u8 *)&corr_le, 7); |
|
|
|
dev_info(&dev->dev, "DS28E04 crc workaround on %02x.%012llx.%02x\n", |
|
tmp->family, (unsigned long long)tmp->id, tmp->crc); |
|
} |
|
|
|
if (crc != tmp->crc) { |
|
dev_dbg(&dev->dev, "w1 addr crc mismatch: %02x.%012llx.%02x != 0x%02x.\n", |
|
tmp->family, (unsigned long long)tmp->id, tmp->crc, crc); |
|
return 0; |
|
} |
|
return 1; |
|
} |
|
|
|
void w1_slave_found(struct w1_master *dev, u64 rn) |
|
{ |
|
struct w1_slave *sl; |
|
struct w1_reg_num *tmp; |
|
|
|
atomic_inc(&dev->refcnt); |
|
|
|
tmp = (struct w1_reg_num *) &rn; |
|
|
|
sl = w1_slave_search_device(dev, tmp); |
|
if (sl) { |
|
set_bit(W1_SLAVE_ACTIVE, &sl->flags); |
|
} else { |
|
if (rn && w1_addr_crc_is_valid(dev, rn)) |
|
w1_attach_slave_device(dev, tmp); |
|
} |
|
|
|
atomic_dec(&dev->refcnt); |
|
} |
|
|
|
/** |
|
* w1_search() - Performs a ROM Search & registers any devices found. |
|
* @dev: The master device to search |
|
* @search_type: W1_SEARCH to search all devices, or W1_ALARM_SEARCH |
|
* to return only devices in the alarmed state |
|
* @cb: Function to call when a device is found |
|
* |
|
* The 1-wire search is a simple binary tree search. |
|
* For each bit of the address, we read two bits and write one bit. |
|
* The bit written will put to sleep all devies that don't match that bit. |
|
* When the two reads differ, the direction choice is obvious. |
|
* When both bits are 0, we must choose a path to take. |
|
* When we can scan all 64 bits without having to choose a path, we are done. |
|
* |
|
* See "Application note 187 1-wire search algorithm" at www.maxim-ic.com |
|
* |
|
*/ |
|
void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb) |
|
{ |
|
u64 last_rn, rn, tmp64; |
|
int i, slave_count = 0; |
|
int last_zero, last_device; |
|
int search_bit, desc_bit; |
|
u8 triplet_ret = 0; |
|
|
|
search_bit = 0; |
|
rn = dev->search_id; |
|
last_rn = 0; |
|
last_device = 0; |
|
last_zero = -1; |
|
|
|
desc_bit = 64; |
|
|
|
while ( !last_device && (slave_count++ < dev->max_slave_count) ) { |
|
last_rn = rn; |
|
rn = 0; |
|
|
|
/* |
|
* Reset bus and all 1-wire device state machines |
|
* so they can respond to our requests. |
|
* |
|
* Return 0 - device(s) present, 1 - no devices present. |
|
*/ |
|
mutex_lock(&dev->bus_mutex); |
|
if (w1_reset_bus(dev)) { |
|
mutex_unlock(&dev->bus_mutex); |
|
dev_dbg(&dev->dev, "No devices present on the wire.\n"); |
|
break; |
|
} |
|
|
|
/* Do fast search on single slave bus */ |
|
if (dev->max_slave_count == 1) { |
|
int rv; |
|
w1_write_8(dev, W1_READ_ROM); |
|
rv = w1_read_block(dev, (u8 *)&rn, 8); |
|
mutex_unlock(&dev->bus_mutex); |
|
|
|
if (rv == 8 && rn) |
|
cb(dev, rn); |
|
|
|
break; |
|
} |
|
|
|
/* Start the search */ |
|
w1_write_8(dev, search_type); |
|
for (i = 0; i < 64; ++i) { |
|
/* Determine the direction/search bit */ |
|
if (i == desc_bit) |
|
search_bit = 1; /* took the 0 path last time, so take the 1 path */ |
|
else if (i > desc_bit) |
|
search_bit = 0; /* take the 0 path on the next branch */ |
|
else |
|
search_bit = ((last_rn >> i) & 0x1); |
|
|
|
/* Read two bits and write one bit */ |
|
triplet_ret = w1_triplet(dev, search_bit); |
|
|
|
/* quit if no device responded */ |
|
if ( (triplet_ret & 0x03) == 0x03 ) |
|
break; |
|
|
|
/* If both directions were valid, and we took the 0 path... */ |
|
if (triplet_ret == 0) |
|
last_zero = i; |
|
|
|
/* extract the direction taken & update the device number */ |
|
tmp64 = (triplet_ret >> 2); |
|
rn |= (tmp64 << i); |
|
|
|
if (test_bit(W1_ABORT_SEARCH, &dev->flags)) { |
|
mutex_unlock(&dev->bus_mutex); |
|
dev_dbg(&dev->dev, "Abort w1_search\n"); |
|
return; |
|
} |
|
} |
|
mutex_unlock(&dev->bus_mutex); |
|
|
|
if ( (triplet_ret & 0x03) != 0x03 ) { |
|
if ((desc_bit == last_zero) || (last_zero < 0)) { |
|
last_device = 1; |
|
dev->search_id = 0; |
|
} else { |
|
dev->search_id = rn; |
|
} |
|
desc_bit = last_zero; |
|
cb(dev, rn); |
|
} |
|
|
|
if (!last_device && slave_count == dev->max_slave_count && |
|
!test_bit(W1_WARN_MAX_COUNT, &dev->flags)) { |
|
/* Only max_slave_count will be scanned in a search, |
|
* but it will start where it left off next search |
|
* until all ids are identified and then it will start |
|
* over. A continued search will report the previous |
|
* last id as the first id (provided it is still on the |
|
* bus). |
|
*/ |
|
dev_info(&dev->dev, "%s: max_slave_count %d reached, " |
|
"will continue next search.\n", __func__, |
|
dev->max_slave_count); |
|
set_bit(W1_WARN_MAX_COUNT, &dev->flags); |
|
} |
|
} |
|
} |
|
|
|
void w1_search_process_cb(struct w1_master *dev, u8 search_type, |
|
w1_slave_found_callback cb) |
|
{ |
|
struct w1_slave *sl, *sln; |
|
|
|
mutex_lock(&dev->list_mutex); |
|
list_for_each_entry(sl, &dev->slist, w1_slave_entry) |
|
clear_bit(W1_SLAVE_ACTIVE, &sl->flags); |
|
mutex_unlock(&dev->list_mutex); |
|
|
|
w1_search_devices(dev, search_type, cb); |
|
|
|
mutex_lock(&dev->list_mutex); |
|
list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) { |
|
if (!test_bit(W1_SLAVE_ACTIVE, &sl->flags) && !--sl->ttl) { |
|
mutex_unlock(&dev->list_mutex); |
|
w1_slave_detach(sl); |
|
mutex_lock(&dev->list_mutex); |
|
} |
|
else if (test_bit(W1_SLAVE_ACTIVE, &sl->flags)) |
|
sl->ttl = dev->slave_ttl; |
|
} |
|
mutex_unlock(&dev->list_mutex); |
|
|
|
if (dev->search_count > 0) |
|
dev->search_count--; |
|
} |
|
|
|
static void w1_search_process(struct w1_master *dev, u8 search_type) |
|
{ |
|
w1_search_process_cb(dev, search_type, w1_slave_found); |
|
} |
|
|
|
/** |
|
* w1_process_callbacks() - execute each dev->async_list callback entry |
|
* @dev: w1_master device |
|
* |
|
* The w1 master list_mutex must be held. |
|
* |
|
* Return: 1 if there were commands to executed 0 otherwise |
|
*/ |
|
int w1_process_callbacks(struct w1_master *dev) |
|
{ |
|
int ret = 0; |
|
struct w1_async_cmd *async_cmd, *async_n; |
|
|
|
/* The list can be added to in another thread, loop until it is empty */ |
|
while (!list_empty(&dev->async_list)) { |
|
list_for_each_entry_safe(async_cmd, async_n, &dev->async_list, |
|
async_entry) { |
|
/* drop the lock, if it is a search it can take a long |
|
* time */ |
|
mutex_unlock(&dev->list_mutex); |
|
async_cmd->cb(dev, async_cmd); |
|
ret = 1; |
|
mutex_lock(&dev->list_mutex); |
|
} |
|
} |
|
return ret; |
|
} |
|
|
|
int w1_process(void *data) |
|
{ |
|
struct w1_master *dev = (struct w1_master *) data; |
|
/* As long as w1_timeout is only set by a module parameter the sleep |
|
* time can be calculated in jiffies once. |
|
*/ |
|
const unsigned long jtime = |
|
usecs_to_jiffies(w1_timeout * 1000000 + w1_timeout_us); |
|
/* remainder if it woke up early */ |
|
unsigned long jremain = 0; |
|
|
|
for (;;) { |
|
|
|
if (!jremain && dev->search_count) { |
|
mutex_lock(&dev->mutex); |
|
w1_search_process(dev, W1_SEARCH); |
|
mutex_unlock(&dev->mutex); |
|
} |
|
|
|
mutex_lock(&dev->list_mutex); |
|
/* Note, w1_process_callback drops the lock while processing, |
|
* but locks it again before returning. |
|
*/ |
|
if (!w1_process_callbacks(dev) && jremain) { |
|
/* a wake up is either to stop the thread, process |
|
* callbacks, or search, it isn't process callbacks, so |
|
* schedule a search. |
|
*/ |
|
jremain = 1; |
|
} |
|
|
|
__set_current_state(TASK_INTERRUPTIBLE); |
|
|
|
/* hold list_mutex until after interruptible to prevent loosing |
|
* the wakeup signal when async_cmd is added. |
|
*/ |
|
mutex_unlock(&dev->list_mutex); |
|
|
|
if (kthread_should_stop()) |
|
break; |
|
|
|
/* Only sleep when the search is active. */ |
|
if (dev->search_count) { |
|
if (!jremain) |
|
jremain = jtime; |
|
jremain = schedule_timeout(jremain); |
|
} |
|
else |
|
schedule(); |
|
} |
|
|
|
atomic_dec(&dev->refcnt); |
|
|
|
return 0; |
|
} |
|
|
|
static int __init w1_init(void) |
|
{ |
|
int retval; |
|
|
|
pr_info("Driver for 1-wire Dallas network protocol.\n"); |
|
|
|
w1_init_netlink(); |
|
|
|
retval = bus_register(&w1_bus_type); |
|
if (retval) { |
|
pr_err("Failed to register bus. err=%d.\n", retval); |
|
goto err_out_exit_init; |
|
} |
|
|
|
retval = driver_register(&w1_master_driver); |
|
if (retval) { |
|
pr_err("Failed to register master driver. err=%d.\n", |
|
retval); |
|
goto err_out_bus_unregister; |
|
} |
|
|
|
retval = driver_register(&w1_slave_driver); |
|
if (retval) { |
|
pr_err("Failed to register slave driver. err=%d.\n", |
|
retval); |
|
goto err_out_master_unregister; |
|
} |
|
|
|
return 0; |
|
|
|
#if 0 |
|
/* For undoing the slave register if there was a step after it. */ |
|
err_out_slave_unregister: |
|
driver_unregister(&w1_slave_driver); |
|
#endif |
|
|
|
err_out_master_unregister: |
|
driver_unregister(&w1_master_driver); |
|
|
|
err_out_bus_unregister: |
|
bus_unregister(&w1_bus_type); |
|
|
|
err_out_exit_init: |
|
return retval; |
|
} |
|
|
|
static void __exit w1_fini(void) |
|
{ |
|
struct w1_master *dev; |
|
|
|
/* Set netlink removal messages and some cleanup */ |
|
list_for_each_entry(dev, &w1_masters, w1_master_entry) |
|
__w1_remove_master_device(dev); |
|
|
|
w1_fini_netlink(); |
|
|
|
driver_unregister(&w1_slave_driver); |
|
driver_unregister(&w1_master_driver); |
|
bus_unregister(&w1_bus_type); |
|
} |
|
|
|
module_init(w1_init); |
|
module_exit(w1_fini); |
|
|
|
MODULE_AUTHOR("Evgeniy Polyakov <[email protected]>"); |
|
MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol."); |
|
MODULE_LICENSE("GPL");
|
|
|