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Diffstat (limited to 'include/linux/w1.h')
| -rw-r--r-- | include/linux/w1.h | 324 |
1 files changed, 324 insertions, 0 deletions
diff --git a/include/linux/w1.h b/include/linux/w1.h new file mode 100644 index 000000000..9a2a0ef39 --- /dev/null +++ b/include/linux/w1.h @@ -0,0 +1,324 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net> + */ + +#ifndef __LINUX_W1_H +#define __LINUX_W1_H + +#include <linux/device.h> + +/** + * struct w1_reg_num - broken out slave device id + * + * @family: identifies the type of device + * @id: along with family is the unique device id + * @crc: checksum of the other bytes + */ +struct w1_reg_num { +#if defined(__LITTLE_ENDIAN_BITFIELD) + __u64 family:8, + id:48, + crc:8; +#elif defined(__BIG_ENDIAN_BITFIELD) + __u64 crc:8, + id:48, + family:8; +#else +#error "Please fix <asm/byteorder.h>" +#endif +}; + +#ifdef __KERNEL__ + +#define W1_MAXNAMELEN 32 + +#define W1_SEARCH 0xF0 +#define W1_ALARM_SEARCH 0xEC +#define W1_CONVERT_TEMP 0x44 +#define W1_SKIP_ROM 0xCC +#define W1_COPY_SCRATCHPAD 0x48 +#define W1_WRITE_SCRATCHPAD 0x4E +#define W1_READ_SCRATCHPAD 0xBE +#define W1_READ_ROM 0x33 +#define W1_READ_PSUPPLY 0xB4 +#define W1_MATCH_ROM 0x55 +#define W1_RESUME_CMD 0xA5 + +/** + * struct w1_slave - holds a single slave device on the bus + * + * @owner: Points to the one wire "wire" kernel module. + * @name: Device id is ascii. + * @w1_slave_entry: data for the linked list + * @reg_num: the slave id in binary + * @refcnt: reference count, delete when 0 + * @flags: bit flags for W1_SLAVE_ACTIVE W1_SLAVE_DETACH + * @ttl: decrement per search this slave isn't found, deatch at 0 + * @master: bus which this slave is on + * @family: module for device family type + * @family_data: pointer for use by the family module + * @dev: kernel device identifier + * @hwmon: pointer to hwmon device + * + */ +struct w1_slave { + struct module *owner; + unsigned char name[W1_MAXNAMELEN]; + struct list_head w1_slave_entry; + struct w1_reg_num reg_num; + atomic_t refcnt; + int ttl; + unsigned long flags; + + struct w1_master *master; + struct w1_family *family; + void *family_data; + struct device dev; + struct device *hwmon; +}; + +typedef void (*w1_slave_found_callback)(struct w1_master *, u64); + +/** + * struct w1_bus_master - operations available on a bus master + * + * @data: the first parameter in all the functions below + * + * @read_bit: Sample the line level @return the level read (0 or 1) + * + * @write_bit: Sets the line level + * + * @touch_bit: the lowest-level function for devices that really support the + * 1-wire protocol. + * touch_bit(0) = write-0 cycle + * touch_bit(1) = write-1 / read cycle + * @return the bit read (0 or 1) + * + * @read_byte: Reads a bytes. Same as 8 touch_bit(1) calls. + * @return the byte read + * + * @write_byte: Writes a byte. Same as 8 touch_bit(x) calls. + * + * @read_block: Same as a series of read_byte() calls + * @return the number of bytes read + * + * @write_block: Same as a series of write_byte() calls + * + * @triplet: Combines two reads and a smart write for ROM searches + * @return bit0=Id bit1=comp_id bit2=dir_taken + * + * @reset_bus: long write-0 with a read for the presence pulse detection + * @return -1=Error, 0=Device present, 1=No device present + * + * @set_pullup: Put out a strong pull-up pulse of the specified duration. + * @return -1=Error, 0=completed + * + * @search: Really nice hardware can handles the different types of ROM search + * w1_master* is passed to the slave found callback. + * u8 is search_type, W1_SEARCH or W1_ALARM_SEARCH + * + * @dev_id: Optional device id string, which w1 slaves could use for + * creating names, which then give a connection to the w1 master + * + * Note: read_bit and write_bit are very low level functions and should only + * be used with hardware that doesn't really support 1-wire operations, + * like a parallel/serial port. + * Either define read_bit and write_bit OR define, at minimum, touch_bit and + * reset_bus. + * + */ +struct w1_bus_master { + void *data; + + u8 (*read_bit)(void *); + + void (*write_bit)(void *, u8); + + u8 (*touch_bit)(void *, u8); + + u8 (*read_byte)(void *); + + void (*write_byte)(void *, u8); + + u8 (*read_block)(void *, u8 *, int); + + void (*write_block)(void *, const u8 *, int); + + u8 (*triplet)(void *, u8); + + u8 (*reset_bus)(void *); + + u8 (*set_pullup)(void *, int); + + void (*search)(void *, struct w1_master *, + u8, w1_slave_found_callback); + + char *dev_id; +}; + +/** + * enum w1_master_flags - bitfields used in w1_master.flags + * @W1_ABORT_SEARCH: abort searching early on shutdown + * @W1_WARN_MAX_COUNT: limit warning when the maximum count is reached + */ +enum w1_master_flags { + W1_ABORT_SEARCH = 0, + W1_WARN_MAX_COUNT = 1, +}; + +/** + * struct w1_master - one per bus master + * @w1_master_entry: master linked list + * @owner: module owner + * @name: dynamically allocate bus name + * @list_mutex: protect slist and async_list + * @slist: linked list of slaves + * @async_list: linked list of netlink commands to execute + * @max_slave_count: maximum number of slaves to search for at a time + * @slave_count: current number of slaves known + * @attempts: number of searches ran + * @slave_ttl: number of searches before a slave is timed out + * @initialized: prevent init/removal race conditions + * @id: w1 bus number + * @search_count: number of automatic searches to run, -1 unlimited + * @search_id: allows continuing a search + * @refcnt: reference count + * @priv: private data storage + * @enable_pullup: allows a strong pullup + * @pullup_duration: time for the next strong pullup + * @flags: one of w1_master_flags + * @thread: thread for bus search and netlink commands + * @mutex: protect most of w1_master + * @bus_mutex: pretect concurrent bus access + * @driver: sysfs driver + * @dev: sysfs device + * @bus_master: io operations available + * @seq: sequence number used for netlink broadcasts + */ +struct w1_master { + struct list_head w1_master_entry; + struct module *owner; + unsigned char name[W1_MAXNAMELEN]; + /* list_mutex protects just slist and async_list so slaves can be + * searched for and async commands added while the master has + * w1_master.mutex locked and is operating on the bus. + * lock order w1_mlock, w1_master.mutex, w1_master.list_mutex + */ + struct mutex list_mutex; + struct list_head slist; + struct list_head async_list; + int max_slave_count, slave_count; + unsigned long attempts; + int slave_ttl; + int initialized; + u32 id; + int search_count; + /* id to start searching on, to continue a search or 0 to restart */ + u64 search_id; + + atomic_t refcnt; + + void *priv; + + /** 5V strong pullup enabled flag, 1 enabled, zero disabled. */ + int enable_pullup; + /** 5V strong pullup duration in milliseconds, zero disabled. */ + int pullup_duration; + + long flags; + + struct task_struct *thread; + struct mutex mutex; + struct mutex bus_mutex; + + struct device_driver *driver; + struct device dev; + + struct w1_bus_master *bus_master; + + u32 seq; +}; + +int w1_add_master_device(struct w1_bus_master *master); +void w1_remove_master_device(struct w1_bus_master *master); + +/** + * struct w1_family_ops - operations for a family type + * @add_slave: add_slave + * @remove_slave: remove_slave + * @groups: sysfs group + * @chip_info: pointer to struct hwmon_chip_info + */ +struct w1_family_ops { + int (*add_slave)(struct w1_slave *sl); + void (*remove_slave)(struct w1_slave *sl); + const struct attribute_group **groups; + const struct hwmon_chip_info *chip_info; +}; + +/** + * struct w1_family - reference counted family structure. + * @family_entry: family linked list + * @fid: 8 bit family identifier + * @fops: operations for this family + * @of_match_table: open firmware match table + * @refcnt: reference counter + */ +struct w1_family { + struct list_head family_entry; + u8 fid; + + const struct w1_family_ops *fops; + + const struct of_device_id *of_match_table; + + atomic_t refcnt; +}; + +int w1_register_family(struct w1_family *family); +void w1_unregister_family(struct w1_family *family); + +/** + * module_w1_family() - Helper macro for registering a 1-Wire families + * @__w1_family: w1_family struct + * + * Helper macro for 1-Wire families which do not do anything special in module + * init/exit. This eliminates a lot of boilerplate. Each module may only + * use this macro once, and calling it replaces module_init() and module_exit() + */ +#define module_w1_family(__w1_family) \ + module_driver(__w1_family, w1_register_family, \ + w1_unregister_family) + +u8 w1_triplet(struct w1_master *dev, int bdir); +u8 w1_touch_bit(struct w1_master *dev, int bit); +void w1_write_8(struct w1_master *, u8); +u8 w1_read_8(struct w1_master *); +int w1_reset_bus(struct w1_master *); +u8 w1_calc_crc8(u8 *, int); +void w1_write_block(struct w1_master *, const u8 *, int); +void w1_touch_block(struct w1_master *, u8 *, int); +u8 w1_read_block(struct w1_master *, u8 *, int); +int w1_reset_select_slave(struct w1_slave *sl); +int w1_reset_resume_command(struct w1_master *); +void w1_next_pullup(struct w1_master *, int); + +static inline struct w1_slave* dev_to_w1_slave(struct device *dev) +{ + return container_of(dev, struct w1_slave, dev); +} + +static inline struct w1_slave* kobj_to_w1_slave(struct kobject *kobj) +{ + return dev_to_w1_slave(container_of(kobj, struct device, kobj)); +} + +static inline struct w1_master* dev_to_w1_master(struct device *dev) +{ + return container_of(dev, struct w1_master, dev); +} + +#endif /* __KERNEL__ */ + +#endif /* __LINUX_W1_H */ |