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linux-sg2042/drivers/w1/slaves/w1_therm.c

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* w1_therm.c
*
* Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
*/
#include <asm/types.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/sched.h>
#include <linux/device.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/hwmon.h>
#include <linux/string.h>
#include <linux/w1.h>
#define W1_THERM_DS18S20 0x10
#define W1_THERM_DS1822 0x22
#define W1_THERM_DS18B20 0x28
#define W1_THERM_DS1825 0x3B
#define W1_THERM_DS28EA00 0x42
/*
* Allow the strong pullup to be disabled, but default to enabled.
* If it was disabled a parasite powered device might not get the require
* current to do a temperature conversion. If it is enabled parasite powered
* devices have a better chance of getting the current required.
* In case the parasite power-detection is not working (seems to be the case
* for some DS18S20) the strong pullup can also be forced, regardless of the
* power state of the devices.
*
* Summary of options:
* - strong_pullup = 0 Disable strong pullup completely
* - strong_pullup = 1 Enable automatic strong pullup detection
* - strong_pullup = 2 Force strong pullup
*/
static int w1_strong_pullup = 1;
module_param_named(strong_pullup, w1_strong_pullup, int, 0);
/* Counter for devices supporting bulk reading */
static u16 bulk_read_device_counter; /* =0 as per C standard */
/* This command should be in public header w1.h but is not */
#define W1_RECALL_EEPROM 0xB8
/* Nb of try for an operation */
#define W1_THERM_MAX_TRY 5
/* ms delay to retry bus mutex */
#define W1_THERM_RETRY_DELAY 20
/* delay in ms to write in EEPROM */
#define W1_THERM_EEPROM_WRITE_DELAY 10
#define EEPROM_CMD_WRITE "save" /* cmd for write eeprom sysfs */
#define EEPROM_CMD_READ "restore" /* cmd for read eeprom sysfs */
#define BULK_TRIGGER_CMD "trigger" /* cmd to trigger a bulk read */
#define MIN_TEMP -55 /* min temperature that can be mesured */
#define MAX_TEMP 125 /* max temperature that can be mesured */
/* Helpers Macros */
/*
* return a pointer on the slave w1_therm_family_converter struct:
* always test family data existence before using this macro
*/
#define SLAVE_SPECIFIC_FUNC(sl) \
(((struct w1_therm_family_data *)(sl->family_data))->specific_functions)
/*
* return the power mode of the sl slave : 1-ext, 0-parasite, <0 unknown
* always test family data existence before using this macro
*/
#define SLAVE_POWERMODE(sl) \
(((struct w1_therm_family_data *)(sl->family_data))->external_powered)
/*
* return the resolution in bit of the sl slave : <0 unknown
* always test family data existence before using this macro
*/
#define SLAVE_RESOLUTION(sl) \
(((struct w1_therm_family_data *)(sl->family_data))->resolution)
/*
* return whether or not a converT command has been issued to the slave
* * 0: no bulk read is pending
* * -1: conversion is in progress
* * 1: conversion done, result to be read
*/
#define SLAVE_CONVERT_TRIGGERED(sl) \
(((struct w1_therm_family_data *)(sl->family_data))->convert_triggered)
/* return the address of the refcnt in the family data */
#define THERM_REFCNT(family_data) \
(&((struct w1_therm_family_data *)family_data)->refcnt)
/* Structs definition */
/**
* struct w1_therm_family_converter - bind device specific functions
* @broken: flag for non-registred families
* @reserved: not used here
* @f: pointer to the device binding structure
* @convert: pointer to the device conversion function
* @get_conversion_time: pointer to the device conversion time function
* @set_resolution: pointer to the device set_resolution function
* @get_resolution: pointer to the device get_resolution function
* @write_data: pointer to the device writing function (2 or 3 bytes)
* @bulk_read: true if device family support bulk read, false otherwise
*/
struct w1_therm_family_converter {
u8 broken;
u16 reserved;
struct w1_family *f;
int (*convert)(u8 rom[9]);
int (*get_conversion_time)(struct w1_slave *sl);
int (*set_resolution)(struct w1_slave *sl, int val);
int (*get_resolution)(struct w1_slave *sl);
int (*write_data)(struct w1_slave *sl, const u8 *data);
bool bulk_read;
};
/**
* struct w1_therm_family_data - device data
* @rom: ROM device id (64bit Lasered ROM code + 1 CRC byte)
* @refcnt: ref count
* @external_powered: 1 device powered externally,
* 0 device parasite powered,
* -x error or undefined
* @resolution: current device resolution
* @convert_triggered: conversion state of the device
* @specific_functions: pointer to struct of device specific function
*/
struct w1_therm_family_data {
uint8_t rom[9];
atomic_t refcnt;
int external_powered;
int resolution;
int convert_triggered;
struct w1_therm_family_converter *specific_functions;
};
/**
* struct therm_info - store temperature reading
* @rom: read device data (8 data bytes + 1 CRC byte)
* @crc: computed crc from rom
* @verdict: 1 crc checked, 0 crc not matching
*/
struct therm_info {
u8 rom[9];
u8 crc;
u8 verdict;
};
/* Hardware Functions declaration */
/**
* reset_select_slave() - reset and select a slave
* @sl: the slave to select
*
* Resets the bus and select the slave by sending a ROM MATCH cmd
* w1_reset_select_slave() from w1_io.c could not be used here because
* it sent a SKIP ROM command if only one device is on the line.
* At the beginning of the such process, sl->master->slave_count is 1 even if
* more devices are on the line, causing collision on the line.
*
* Context: The w1 master lock must be held.
*
* Return: 0 if success, negative kernel error code otherwise.
*/
static int reset_select_slave(struct w1_slave *sl);
/**
* convert_t() - Query the device for temperature conversion and read
* @sl: pointer to the slave to read
* @info: pointer to a structure to store the read results
*
* Return: 0 if success, -kernel error code otherwise
*/
static int convert_t(struct w1_slave *sl, struct therm_info *info);
/**
* read_scratchpad() - read the data in device RAM
* @sl: pointer to the slave to read
* @info: pointer to a structure to store the read results
*
* Return: 0 if success, -kernel error code otherwise
*/
static int read_scratchpad(struct w1_slave *sl, struct therm_info *info);
/**
* write_scratchpad() - write nb_bytes in the device RAM
* @sl: pointer to the slave to write in
* @data: pointer to an array of 3 bytes, as 3 bytes MUST be written
* @nb_bytes: number of bytes to be written (2 for DS18S20, 3 otherwise)
*
* Return: 0 if success, -kernel error code otherwise
*/
static int write_scratchpad(struct w1_slave *sl, const u8 *data, u8 nb_bytes);
/**
* copy_scratchpad() - Copy the content of scratchpad in device EEPROM
* @sl: slave involved
*
* Return: 0 if success, -kernel error code otherwise
*/
static int copy_scratchpad(struct w1_slave *sl);
/**
* recall_eeprom() - Restore EEPROM data to device RAM
* @sl: slave involved
*
* Return: 0 if success, -kernel error code otherwise
*/
static int recall_eeprom(struct w1_slave *sl);
/**
* read_powermode() - Query the power mode of the slave
* @sl: slave to retrieve the power mode
*
* Ask the device to get its power mode (external or parasite)
* and store the power status in the &struct w1_therm_family_data.
*
* Return:
* * 0 parasite powered device
* * 1 externally powered device
* * <0 kernel error code
*/
static int read_powermode(struct w1_slave *sl);
/**
* trigger_bulk_read() - function to trigger a bulk read on the bus
* @dev_master: the device master of the bus
*
* Send a SKIP ROM follow by a CONVERT T commmand on the bus.
* It also set the status flag in each slave &struct w1_therm_family_data
* to signal that a conversion is in progress.
*
* Return: 0 if success, -kernel error code otherwise
*/
static int trigger_bulk_read(struct w1_master *dev_master);
/* Sysfs interface declaration */
static ssize_t w1_slave_show(struct device *device,
struct device_attribute *attr, char *buf);
static ssize_t w1_slave_store(struct device *device,
struct device_attribute *attr, const char *buf, size_t size);
static ssize_t w1_seq_show(struct device *device,
struct device_attribute *attr, char *buf);
static ssize_t temperature_show(struct device *device,
struct device_attribute *attr, char *buf);
static ssize_t ext_power_show(struct device *device,
struct device_attribute *attr, char *buf);
static ssize_t resolution_show(struct device *device,
struct device_attribute *attr, char *buf);
static ssize_t resolution_store(struct device *device,
struct device_attribute *attr, const char *buf, size_t size);
static ssize_t eeprom_store(struct device *device,
struct device_attribute *attr, const char *buf, size_t size);
static ssize_t alarms_store(struct device *device,
struct device_attribute *attr, const char *buf, size_t size);
static ssize_t alarms_show(struct device *device,
struct device_attribute *attr, char *buf);
static ssize_t therm_bulk_read_store(struct device *device,
struct device_attribute *attr, const char *buf, size_t size);
static ssize_t therm_bulk_read_show(struct device *device,
struct device_attribute *attr, char *buf);
/* Attributes declarations */
static DEVICE_ATTR_RW(w1_slave);
static DEVICE_ATTR_RO(w1_seq);
static DEVICE_ATTR_RO(temperature);
static DEVICE_ATTR_RO(ext_power);
static DEVICE_ATTR_RW(resolution);
static DEVICE_ATTR_WO(eeprom);
static DEVICE_ATTR_RW(alarms);
static DEVICE_ATTR_RW(therm_bulk_read); /* attribut at master level */
/* Interface Functions declaration */
/**
* w1_therm_add_slave() - Called when a new slave is discovered
* @sl: slave just discovered by the master.
*
* Called by the master when the slave is discovered on the bus. Used to
* initialize slave state before the beginning of any communication.
*
* Return: 0 - If success, negative kernel code otherwise
*/
static int w1_therm_add_slave(struct w1_slave *sl);
/**
* w1_therm_remove_slave() - Called when a slave is removed
* @sl: slave to be removed.
*
* Called by the master when the slave is considered not to be on the bus
* anymore. Used to free memory.
*/
static void w1_therm_remove_slave(struct w1_slave *sl);
/* Family attributes */
static struct attribute *w1_therm_attrs[] = {
&dev_attr_w1_slave.attr,
&dev_attr_temperature.attr,
&dev_attr_ext_power.attr,
&dev_attr_resolution.attr,
&dev_attr_eeprom.attr,
&dev_attr_alarms.attr,
NULL,
};
static struct attribute *w1_ds18s20_attrs[] = {
&dev_attr_w1_slave.attr,
&dev_attr_temperature.attr,
&dev_attr_ext_power.attr,
&dev_attr_eeprom.attr,
&dev_attr_alarms.attr,
NULL,
};
static struct attribute *w1_ds28ea00_attrs[] = {
&dev_attr_w1_slave.attr,
&dev_attr_w1_seq.attr,
&dev_attr_temperature.attr,
&dev_attr_ext_power.attr,
&dev_attr_resolution.attr,
&dev_attr_eeprom.attr,
&dev_attr_alarms.attr,
NULL,
};
/* Attribute groups */
ATTRIBUTE_GROUPS(w1_therm);
ATTRIBUTE_GROUPS(w1_ds18s20);
ATTRIBUTE_GROUPS(w1_ds28ea00);
#if IS_REACHABLE(CONFIG_HWMON)
static int w1_read_temp(struct device *dev, u32 attr, int channel,
long *val);
static umode_t w1_is_visible(const void *_data, enum hwmon_sensor_types type,
u32 attr, int channel)
{
return attr == hwmon_temp_input ? 0444 : 0;
}
static int w1_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *val)
{
switch (type) {
case hwmon_temp:
return w1_read_temp(dev, attr, channel, val);
default:
return -EOPNOTSUPP;
}
}
static const u32 w1_temp_config[] = {
HWMON_T_INPUT,
0
};
static const struct hwmon_channel_info w1_temp = {
.type = hwmon_temp,
.config = w1_temp_config,
};
static const struct hwmon_channel_info *w1_info[] = {
&w1_temp,
NULL
};
static const struct hwmon_ops w1_hwmon_ops = {
.is_visible = w1_is_visible,
.read = w1_read,
};
static const struct hwmon_chip_info w1_chip_info = {
.ops = &w1_hwmon_ops,
.info = w1_info,
};
#define W1_CHIPINFO (&w1_chip_info)
#else
#define W1_CHIPINFO NULL
#endif
/* Family operations */
static struct w1_family_ops w1_therm_fops = {
.add_slave = w1_therm_add_slave,
.remove_slave = w1_therm_remove_slave,
.groups = w1_therm_groups,
.chip_info = W1_CHIPINFO,
};
static struct w1_family_ops w1_ds18s20_fops = {
.add_slave = w1_therm_add_slave,
.remove_slave = w1_therm_remove_slave,
.groups = w1_ds18s20_groups,
.chip_info = W1_CHIPINFO,
};
static struct w1_family_ops w1_ds28ea00_fops = {
.add_slave = w1_therm_add_slave,
.remove_slave = w1_therm_remove_slave,
.groups = w1_ds28ea00_groups,
.chip_info = W1_CHIPINFO,
};
/* Family binding operations struct */
static struct w1_family w1_therm_family_DS18S20 = {
.fid = W1_THERM_DS18S20,
.fops = &w1_ds18s20_fops,
};
static struct w1_family w1_therm_family_DS18B20 = {
.fid = W1_THERM_DS18B20,
.fops = &w1_therm_fops,
};
static struct w1_family w1_therm_family_DS1822 = {
.fid = W1_THERM_DS1822,
.fops = &w1_therm_fops,
};
static struct w1_family w1_therm_family_DS28EA00 = {
.fid = W1_THERM_DS28EA00,
.fops = &w1_ds28ea00_fops,
};
static struct w1_family w1_therm_family_DS1825 = {
.fid = W1_THERM_DS1825,
.fops = &w1_therm_fops,
};
/* Device dependent func */
static inline int w1_DS18B20_convert_time(struct w1_slave *sl)
{
int ret;
if (!sl->family_data)
return -ENODEV; /* device unknown */
/* return time in ms for conversion operation */
switch (SLAVE_RESOLUTION(sl)) {
case 9:
ret = 95;
break;
case 10:
ret = 190;
break;
case 11:
ret = 375;
break;
case 12:
default:
ret = 750;
}
return ret;
}
static inline int w1_DS18S20_convert_time(struct w1_slave *sl)
{
(void)(sl);
return 750; /* always 750ms for DS18S20 */
}
static inline int w1_DS18B20_write_data(struct w1_slave *sl,
const u8 *data)
{
return write_scratchpad(sl, data, 3);
}
static inline int w1_DS18S20_write_data(struct w1_slave *sl,
const u8 *data)
{
/* No config register */
return write_scratchpad(sl, data, 2);
}
static inline int w1_DS18B20_set_resolution(struct w1_slave *sl, int val)
{
int ret;
u8 new_config_register[3]; /* array of data to be written */
struct therm_info info;
/* resolution of DS18B20 is in the range [9..12] bits */
if (val < 9 || val > 12)
return -EINVAL;
val -= 9; /* soustract 9 the lowest resolution in bit */
val = (val << 5); /* shift to position bit 5 & bit 6 */
/*
* Read the scratchpad to change only the required bits
* (bit5 & bit 6 from byte 4)
*/
ret = read_scratchpad(sl, &info);
if (!ret) {
new_config_register[0] = info.rom[2];
new_config_register[1] = info.rom[3];
/* config register is byte 4 & mask 0b10011111*/
new_config_register[2] = (info.rom[4] & 0x9F) |
(u8) val;
} else
return ret;
/* Write data in the device RAM */
ret = w1_DS18B20_write_data(sl, new_config_register);
return ret;
}
static inline int w1_DS18B20_get_resolution(struct w1_slave *sl)
{
int ret;
u8 config_register;
struct therm_info info;
ret = read_scratchpad(sl, &info);
if (!ret) {
config_register = info.rom[4]; /* config register is byte 4 */
config_register &= 0x60; /* 0b01100000 keep only bit 5 & 6 */
config_register = (config_register >> 5); /* shift */
config_register += 9; /* add 9 the lowest resolution in bit */
ret = (int) config_register;
}
return ret;
}
/**
* w1_DS18B20_convert_temp() - temperature computation for DS18B20
* @rom: data read from device RAM (8 data bytes + 1 CRC byte)
*
* Can be called for any DS18B20 compliant device.
*
* Return: value in millidegrees Celsius.
*/
static inline int w1_DS18B20_convert_temp(u8 rom[9])
{
s16 t = le16_to_cpup((__le16 *)rom);
return t*1000/16;
}
/**
* w1_DS18S20_convert_temp() - temperature computation for DS18S20
* @rom: data read from device RAM (8 data bytes + 1 CRC byte)
*
* Can be called for any DS18S20 compliant device.
*
* Return: value in millidegrees Celsius.
*/
static inline int w1_DS18S20_convert_temp(u8 rom[9])
{
int t, h;
if (!rom[7]) {
pr_debug("%s: Invalid argument for conversion\n", __func__);
return 0;
}
if (rom[1] == 0)
t = ((s32)rom[0] >> 1)*1000;
else
t = 1000*(-1*(s32)(0x100-rom[0]) >> 1);
t -= 250;
h = 1000*((s32)rom[7] - (s32)rom[6]);
h /= (s32)rom[7];
t += h;
return t;
}
/* Device capability description */
static struct w1_therm_family_converter w1_therm_families[] = {
{
.f = &w1_therm_family_DS18S20,
.convert = w1_DS18S20_convert_temp,
.get_conversion_time = w1_DS18S20_convert_time,
.set_resolution = NULL, /* no config register */
.get_resolution = NULL, /* no config register */
.write_data = w1_DS18S20_write_data,
.bulk_read = true
},
{
.f = &w1_therm_family_DS1822,
.convert = w1_DS18B20_convert_temp,
.get_conversion_time = w1_DS18B20_convert_time,
.set_resolution = w1_DS18B20_set_resolution,
.get_resolution = w1_DS18B20_get_resolution,
.write_data = w1_DS18B20_write_data,
.bulk_read = true
},
{
.f = &w1_therm_family_DS18B20,
.convert = w1_DS18B20_convert_temp,
.get_conversion_time = w1_DS18B20_convert_time,
.set_resolution = w1_DS18B20_set_resolution,
.get_resolution = w1_DS18B20_get_resolution,
.write_data = w1_DS18B20_write_data,
.bulk_read = true
},
{
.f = &w1_therm_family_DS28EA00,
.convert = w1_DS18B20_convert_temp,
.get_conversion_time = w1_DS18B20_convert_time,
.set_resolution = w1_DS18B20_set_resolution,
.get_resolution = w1_DS18B20_get_resolution,
.write_data = w1_DS18B20_write_data,
.bulk_read = false
},
{
.f = &w1_therm_family_DS1825,
.convert = w1_DS18B20_convert_temp,
.get_conversion_time = w1_DS18B20_convert_time,
.set_resolution = w1_DS18B20_set_resolution,
.get_resolution = w1_DS18B20_get_resolution,
.write_data = w1_DS18B20_write_data,
.bulk_read = true
}
};
/* Helpers Functions */
/**
* device_family() - Retrieve a pointer on &struct w1_therm_family_converter
* @sl: slave to retrieve the device specific structure
*
* Return: pointer to the slaves's family converter, NULL if not known
*/
static struct w1_therm_family_converter *device_family(struct w1_slave *sl)
{
struct w1_therm_family_converter *ret = NULL;
int i;
for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
if (w1_therm_families[i].f->fid == sl->family->fid) {
ret = &w1_therm_families[i];
break;
}
}
return ret;
}
/**
* bus_mutex_lock() - Acquire the mutex
* @lock: w1 bus mutex to acquire
*
* It try to acquire the mutex W1_THERM_MAX_TRY times and wait
* W1_THERM_RETRY_DELAY between 2 attempts.
*
* Return: true is mutex is acquired and lock, false otherwise
*/
static inline bool bus_mutex_lock(struct mutex *lock)
{
int max_trying = W1_THERM_MAX_TRY;
/* try to acquire the mutex, if not, sleep retry_delay before retry) */
while (mutex_lock_interruptible(lock) != 0 && max_trying > 0) {
unsigned long sleep_rem;
sleep_rem = msleep_interruptible(W1_THERM_RETRY_DELAY);
if (!sleep_rem)
max_trying--;
}
if (!max_trying)
return false; /* Didn't acquire the bus mutex */
return true;
}
/**
* support_bulk_read() - check if slave support bulk read
* @sl: device to check the ability
*
* Return: true if bulk read is supported, false if not or error
*/
static inline bool bulk_read_support(struct w1_slave *sl)
{
if (SLAVE_SPECIFIC_FUNC(sl))
return SLAVE_SPECIFIC_FUNC(sl)->bulk_read;
dev_info(&sl->dev,
"%s: Device not supported by the driver\n", __func__);
return false; /* No device family */
}
/**
* conversion_time() - get the Tconv for the slave
* @sl: device to get the conversion time
*
* On device supporting resolution settings, conversion time depend
* on the resolution setting. This helper function get the slave timing,
* depending on its current setting.
*
* Return: conversion time in ms, negative values are kernel error code
*/
static inline int conversion_time(struct w1_slave *sl)
{
if (SLAVE_SPECIFIC_FUNC(sl))
return SLAVE_SPECIFIC_FUNC(sl)->get_conversion_time(sl);
dev_info(&sl->dev,
"%s: Device not supported by the driver\n", __func__);
return -ENODEV; /* No device family */
}
/**
* temperature_from_RAM() - Convert the read info to temperature
* @sl: device that sent the RAM data
* @rom: read value on the slave device RAM
*
* Device dependent, the function bind the correct computation method.
*
* Return: temperature in 1/1000degC, 0 on error.
*/
static inline int temperature_from_RAM(struct w1_slave *sl, u8 rom[9])
{
if (SLAVE_SPECIFIC_FUNC(sl))
return SLAVE_SPECIFIC_FUNC(sl)->convert(rom);
dev_info(&sl->dev,
"%s: Device not supported by the driver\n", __func__);
return 0; /* No device family */
}
/**
* int_to_short() - Safe casting of int to short
*
* @i: integer to be converted to short
*
* Device register use 1 byte to store signed integer.
* This helper function convert the int in a signed short,
* using the min/max values that device can measure as limits.
* min/max values are defined by macro.
*
* Return: a short in the range of min/max value
*/
static inline s8 int_to_short(int i)
{
/* Prepare to cast to short by eliminating out of range values */
i = i > MAX_TEMP ? MAX_TEMP : i;
i = i < MIN_TEMP ? MIN_TEMP : i;
return (s8) i;
}
/* Interface Functions */
static int w1_therm_add_slave(struct w1_slave *sl)
{
struct w1_therm_family_converter *sl_family_conv;
/* Allocate memory */
sl->family_data = kzalloc(sizeof(struct w1_therm_family_data),
GFP_KERNEL);
if (!sl->family_data)
return -ENOMEM;
atomic_set(THERM_REFCNT(sl->family_data), 1);
/* Get a pointer to the device specific function struct */
sl_family_conv = device_family(sl);
if (!sl_family_conv) {
kfree(sl->family_data);
return -ENODEV;
}
/* save this pointer to the device structure */
SLAVE_SPECIFIC_FUNC(sl) = sl_family_conv;
if (bulk_read_support(sl)) {
/*
* add the sys entry to trigger bulk_read
* at master level only the 1st time
*/
if (!bulk_read_device_counter) {
int err = device_create_file(&sl->master->dev,
&dev_attr_therm_bulk_read);
if (err)
dev_warn(&sl->dev,
"%s: Device has been added, but bulk read is unavailable. err=%d\n",
__func__, err);
}
/* Increment the counter */
bulk_read_device_counter++;
}
/* Getting the power mode of the device {external, parasite} */
SLAVE_POWERMODE(sl) = read_powermode(sl);
if (SLAVE_POWERMODE(sl) < 0) {
/* no error returned as device has been added */
dev_warn(&sl->dev,
"%s: Device has been added, but power_mode may be corrupted. err=%d\n",
__func__, SLAVE_POWERMODE(sl));
}
/* Getting the resolution of the device */
if (SLAVE_SPECIFIC_FUNC(sl)->get_resolution) {
SLAVE_RESOLUTION(sl) =
SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl);
if (SLAVE_RESOLUTION(sl) < 0) {
/* no error returned as device has been added */
dev_warn(&sl->dev,
"%s:Device has been added, but resolution may be corrupted. err=%d\n",
__func__, SLAVE_RESOLUTION(sl));
}
}
/* Finally initialize convert_triggered flag */
SLAVE_CONVERT_TRIGGERED(sl) = 0;
return 0;
}
static void w1_therm_remove_slave(struct w1_slave *sl)
{
int refcnt = atomic_sub_return(1, THERM_REFCNT(sl->family_data));
if (bulk_read_support(sl)) {
bulk_read_device_counter--;
/* Delete the entry if no more device support the feature */
if (!bulk_read_device_counter)
device_remove_file(&sl->master->dev,
&dev_attr_therm_bulk_read);
}
while (refcnt) {
msleep(1000);
refcnt = atomic_read(THERM_REFCNT(sl->family_data));
}
kfree(sl->family_data);
sl->family_data = NULL;
}
/* Hardware Functions */
/* Safe version of reset_select_slave - avoid using the one in w_io.c */
static int reset_select_slave(struct w1_slave *sl)
{
u8 match[9] = { W1_MATCH_ROM, };
u64 rn = le64_to_cpu(*((u64 *)&sl->reg_num));
if (w1_reset_bus(sl->master))
return -ENODEV;
memcpy(&match[1], &rn, 8);
w1_write_block(sl->master, match, 9);
return 0;
}
static int convert_t(struct w1_slave *sl, struct therm_info *info)
{
struct w1_master *dev_master = sl->master;
int max_trying = W1_THERM_MAX_TRY;
int t_conv;
int ret = -ENODEV;
bool strong_pullup;
if (!sl->family_data)
goto error;
strong_pullup = (w1_strong_pullup == 2 ||
(!SLAVE_POWERMODE(sl) &&
w1_strong_pullup));
/* get conversion duration device and id dependent */
t_conv = conversion_time(sl);
memset(info->rom, 0, sizeof(info->rom));
/* prevent the slave from going away in sleep */
atomic_inc(THERM_REFCNT(sl->family_data));
if (!bus_mutex_lock(&dev_master->bus_mutex)) {
ret = -EAGAIN; /* Didn't acquire the mutex */
goto dec_refcnt;
}
while (max_trying-- && ret) { /* ret should be 0 */
info->verdict = 0;
info->crc = 0;
/* safe version to select slave */
if (!reset_select_slave(sl)) {
unsigned long sleep_rem;
/* 750ms strong pullup (or delay) after the convert */
if (strong_pullup)
w1_next_pullup(dev_master, t_conv);
w1_write_8(dev_master, W1_CONVERT_TEMP);
if (strong_pullup) { /*some device need pullup */
sleep_rem = msleep_interruptible(t_conv);
if (sleep_rem != 0) {
ret = -EINTR;
goto mt_unlock;
}
mutex_unlock(&dev_master->bus_mutex);
} else { /*no device need pullup */
mutex_unlock(&dev_master->bus_mutex);
sleep_rem = msleep_interruptible(t_conv);
if (sleep_rem != 0) {
ret = -EINTR;
goto dec_refcnt;
}
}
ret = read_scratchpad(sl, info);
goto dec_refcnt;
}
}
mt_unlock:
mutex_unlock(&dev_master->bus_mutex);
dec_refcnt:
atomic_dec(THERM_REFCNT(sl->family_data));
error:
return ret;
}
static int read_scratchpad(struct w1_slave *sl, struct therm_info *info)
{
struct w1_master *dev_master = sl->master;
int max_trying = W1_THERM_MAX_TRY;
int ret = -ENODEV;
info->verdict = 0;
if (!sl->family_data)
goto error;
memset(info->rom, 0, sizeof(info->rom));
/* prevent the slave from going away in sleep */
atomic_inc(THERM_REFCNT(sl->family_data));
if (!bus_mutex_lock(&dev_master->bus_mutex)) {
ret = -EAGAIN; /* Didn't acquire the mutex */
goto dec_refcnt;
}
while (max_trying-- && ret) { /* ret should be 0 */
/* safe version to select slave */
if (!reset_select_slave(sl)) {
u8 nb_bytes_read;
w1_write_8(dev_master, W1_READ_SCRATCHPAD);
nb_bytes_read = w1_read_block(dev_master, info->rom, 9);
if (nb_bytes_read != 9) {
dev_warn(&sl->dev,
"w1_read_block(): returned %u instead of 9.\n",
nb_bytes_read);
ret = -EIO;
}
info->crc = w1_calc_crc8(info->rom, 8);
if (info->rom[8] == info->crc) {
info->verdict = 1;
ret = 0;
} else
ret = -EIO; /* CRC not checked */
}
}
mutex_unlock(&dev_master->bus_mutex);
dec_refcnt:
atomic_dec(THERM_REFCNT(sl->family_data));
error:
return ret;
}
static int write_scratchpad(struct w1_slave *sl, const u8 *data, u8 nb_bytes)
{
struct w1_master *dev_master = sl->master;
int max_trying = W1_THERM_MAX_TRY;
int ret = -ENODEV;
if (!sl->family_data)
goto error;
/* prevent the slave from going away in sleep */
atomic_inc(THERM_REFCNT(sl->family_data));
if (!bus_mutex_lock(&dev_master->bus_mutex)) {
ret = -EAGAIN; /* Didn't acquire the mutex */
goto dec_refcnt;
}
while (max_trying-- && ret) { /* ret should be 0 */
/* safe version to select slave */
if (!reset_select_slave(sl)) {
w1_write_8(dev_master, W1_WRITE_SCRATCHPAD);
w1_write_block(dev_master, data, nb_bytes);
ret = 0;
}
}
mutex_unlock(&dev_master->bus_mutex);
dec_refcnt:
atomic_dec(THERM_REFCNT(sl->family_data));
error:
return ret;
}
static int copy_scratchpad(struct w1_slave *sl)
{
struct w1_master *dev_master = sl->master;
int max_trying = W1_THERM_MAX_TRY;
int t_write, ret = -ENODEV;
bool strong_pullup;
if (!sl->family_data)
goto error;
t_write = W1_THERM_EEPROM_WRITE_DELAY;
strong_pullup = (w1_strong_pullup == 2 ||
(!SLAVE_POWERMODE(sl) &&
w1_strong_pullup));
/* prevent the slave from going away in sleep */
atomic_inc(THERM_REFCNT(sl->family_data));
if (!bus_mutex_lock(&dev_master->bus_mutex)) {
ret = -EAGAIN; /* Didn't acquire the mutex */
goto dec_refcnt;
}
while (max_trying-- && ret) { /* ret should be 0 */
/* safe version to select slave */
if (!reset_select_slave(sl)) {
unsigned long sleep_rem;
/* 10ms strong pullup (or delay) after the convert */
if (strong_pullup)
w1_next_pullup(dev_master, t_write);
w1_write_8(dev_master, W1_COPY_SCRATCHPAD);
if (strong_pullup) {
sleep_rem = msleep_interruptible(t_write);
if (sleep_rem != 0) {
ret = -EINTR;
goto mt_unlock;
}
}
ret = 0;
}
}
mt_unlock:
mutex_unlock(&dev_master->bus_mutex);
dec_refcnt:
atomic_dec(THERM_REFCNT(sl->family_data));
error:
return ret;
}
static int recall_eeprom(struct w1_slave *sl)
{
struct w1_master *dev_master = sl->master;
int max_trying = W1_THERM_MAX_TRY;
int ret = -ENODEV;
if (!sl->family_data)
goto error;
/* prevent the slave from going away in sleep */
atomic_inc(THERM_REFCNT(sl->family_data));
if (!bus_mutex_lock(&dev_master->bus_mutex)) {
ret = -EAGAIN; /* Didn't acquire the mutex */
goto dec_refcnt;
}
while (max_trying-- && ret) { /* ret should be 0 */
/* safe version to select slave */
if (!reset_select_slave(sl)) {
w1_write_8(dev_master, W1_RECALL_EEPROM);
ret = 1; /* Slave will pull line to 0 */
while (ret)
ret = 1 - w1_touch_bit(dev_master, 1);
}
}
mutex_unlock(&dev_master->bus_mutex);
dec_refcnt:
atomic_dec(THERM_REFCNT(sl->family_data));
error:
return ret;
}
static int read_powermode(struct w1_slave *sl)
{
struct w1_master *dev_master = sl->master;
int max_trying = W1_THERM_MAX_TRY;
int ret = -ENODEV;
if (!sl->family_data)
goto error;
/* prevent the slave from going away in sleep */
atomic_inc(THERM_REFCNT(sl->family_data));
if (!bus_mutex_lock(&dev_master->bus_mutex)) {
ret = -EAGAIN; /* Didn't acquire the mutex */
goto dec_refcnt;
}
while ((max_trying--) && (ret < 0)) {
/* safe version to select slave */
if (!reset_select_slave(sl)) {
w1_write_8(dev_master, W1_READ_PSUPPLY);
/*
* Emit a read time slot and read only one bit,
* 1 is externally powered,
* 0 is parasite powered
*/
ret = w1_touch_bit(dev_master, 1);
/* ret should be either 1 either 0 */
}
}
mutex_unlock(&dev_master->bus_mutex);
dec_refcnt:
atomic_dec(THERM_REFCNT(sl->family_data));
error:
return ret;
}
static int trigger_bulk_read(struct w1_master *dev_master)
{
struct w1_slave *sl = NULL; /* used to iterate through slaves */
int max_trying = W1_THERM_MAX_TRY;
int t_conv = 0;
int ret = -ENODEV;
bool strong_pullup = false;
/*
* Check whether there are parasite powered device on the bus,
* and compute duration of conversion for these devices
* so we can apply a strong pullup if required
*/
list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
if (!sl->family_data)
goto error;
if (bulk_read_support(sl)) {
int t_cur = conversion_time(sl);
t_conv = t_cur > t_conv ? t_cur : t_conv;
strong_pullup = strong_pullup ||
(w1_strong_pullup == 2 ||
(!SLAVE_POWERMODE(sl) &&
w1_strong_pullup));
}
}
/*
* t_conv is the max conversion time required on the bus
* If its 0, no device support the bulk read feature
*/
if (!t_conv)
goto error;
if (!bus_mutex_lock(&dev_master->bus_mutex)) {
ret = -EAGAIN; /* Didn't acquire the mutex */
goto error;
}
while ((max_trying--) && (ret < 0)) { /* ret should be either 0 */
if (!w1_reset_bus(dev_master)) { /* Just reset the bus */
unsigned long sleep_rem;
w1_write_8(dev_master, W1_SKIP_ROM);
if (strong_pullup) /* Apply pullup if required */
w1_next_pullup(dev_master, t_conv);
w1_write_8(dev_master, W1_CONVERT_TEMP);
/* set a flag to instruct that converT pending */
list_for_each_entry(sl,
&dev_master->slist, w1_slave_entry) {
if (bulk_read_support(sl))
SLAVE_CONVERT_TRIGGERED(sl) = -1;
}
if (strong_pullup) { /* some device need pullup */
sleep_rem = msleep_interruptible(t_conv);
if (sleep_rem != 0) {
ret = -EINTR;
goto mt_unlock;
}
mutex_unlock(&dev_master->bus_mutex);
} else {
mutex_unlock(&dev_master->bus_mutex);
sleep_rem = msleep_interruptible(t_conv);
if (sleep_rem != 0) {
ret = -EINTR;
goto set_flag;
}
}
ret = 0;
goto set_flag;
}
}
mt_unlock:
mutex_unlock(&dev_master->bus_mutex);
set_flag:
/* set a flag to register convsersion is done */
list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
if (bulk_read_support(sl))
SLAVE_CONVERT_TRIGGERED(sl) = 1;
}
error:
return ret;
}
/* Sysfs Interface definition */
static ssize_t w1_slave_show(struct device *device,
struct device_attribute *attr, char *buf)
{
struct w1_slave *sl = dev_to_w1_slave(device);
struct therm_info info;
u8 *family_data = sl->family_data;
int ret, i;
ssize_t c = PAGE_SIZE;
if (bulk_read_support(sl)) {
if (SLAVE_CONVERT_TRIGGERED(sl) < 0) {
dev_dbg(device,
"%s: Conversion in progress, retry later\n",
__func__);
return 0;
} else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) {
/* A bulk read has been issued, read the device RAM */
ret = read_scratchpad(sl, &info);
SLAVE_CONVERT_TRIGGERED(sl) = 0;
} else
ret = convert_t(sl, &info);
} else
ret = convert_t(sl, &info);
if (ret < 0) {
dev_dbg(device,
"%s: Temperature data may be corrupted. err=%d\n",
__func__, ret);
return 0;
}
for (i = 0; i < 9; ++i)
c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", info.rom[i]);
c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n",
info.crc, (info.verdict) ? "YES" : "NO");
if (info.verdict)
memcpy(family_data, info.rom, sizeof(info.rom));
else
dev_warn(device, "%s:Read failed CRC check\n", __func__);
for (i = 0; i < 9; ++i)
c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ",
((u8 *)family_data)[i]);
c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n",
temperature_from_RAM(sl, info.rom));
ret = PAGE_SIZE - c;
return ret;
}
static ssize_t w1_slave_store(struct device *device,
struct device_attribute *attr, const char *buf,
size_t size)
{
int val, ret = 0;
struct w1_slave *sl = dev_to_w1_slave(device);
ret = kstrtoint(buf, 10, &val); /* converting user entry to int */
if (ret) { /* conversion error */
dev_info(device,
"%s: conversion error. err= %d\n", __func__, ret);
return size; /* return size to avoid call back again */
}
if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
dev_info(device,
"%s: Device not supported by the driver\n", __func__);
return size; /* No device family */
}
if (val == 0) /* val=0 : trigger a EEPROM save */
ret = copy_scratchpad(sl);
else {
if (SLAVE_SPECIFIC_FUNC(sl)->set_resolution)
ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val);
}
if (ret) {
dev_info(device,
"%s: writing error %d\n", __func__, ret);
/* return size to avoid call back again */
} else
SLAVE_RESOLUTION(sl) = val;
return size; /* always return size to avoid infinite calling */
}
static ssize_t temperature_show(struct device *device,
struct device_attribute *attr, char *buf)
{
struct w1_slave *sl = dev_to_w1_slave(device);
struct therm_info info;
int ret = 0;
if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
dev_info(device,
"%s: Device not supported by the driver\n", __func__);
return 0; /* No device family */
}
if (bulk_read_support(sl)) {
if (SLAVE_CONVERT_TRIGGERED(sl) < 0) {
dev_dbg(device,
"%s: Conversion in progress, retry later\n",
__func__);
return 0;
} else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) {
/* A bulk read has been issued, read the device RAM */
ret = read_scratchpad(sl, &info);
SLAVE_CONVERT_TRIGGERED(sl) = 0;
} else
ret = convert_t(sl, &info);
} else
ret = convert_t(sl, &info);
if (ret < 0) {
dev_dbg(device,
"%s: Temperature data may be corrupted. err=%d\n",
__func__, ret);
return 0;
}
return sprintf(buf, "%d\n", temperature_from_RAM(sl, info.rom));
}
static ssize_t ext_power_show(struct device *device,
struct device_attribute *attr, char *buf)
{
struct w1_slave *sl = dev_to_w1_slave(device);
if (!sl->family_data) {
dev_info(device,
"%s: Device not supported by the driver\n", __func__);
return 0; /* No device family */
}
/* Getting the power mode of the device {external, parasite} */
SLAVE_POWERMODE(sl) = read_powermode(sl);
if (SLAVE_POWERMODE(sl) < 0) {
dev_dbg(device,
"%s: Power_mode may be corrupted. err=%d\n",
__func__, SLAVE_POWERMODE(sl));
}
return sprintf(buf, "%d\n", SLAVE_POWERMODE(sl));
}
static ssize_t resolution_show(struct device *device,
struct device_attribute *attr, char *buf)
{
struct w1_slave *sl = dev_to_w1_slave(device);
if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
dev_info(device,
"%s: Device not supported by the driver\n", __func__);
return 0; /* No device family */
}
/* get the correct function depending on the device */
SLAVE_RESOLUTION(sl) = SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl);
if (SLAVE_RESOLUTION(sl) < 0) {
dev_dbg(device,
"%s: Resolution may be corrupted. err=%d\n",
__func__, SLAVE_RESOLUTION(sl));
}
return sprintf(buf, "%d\n", SLAVE_RESOLUTION(sl));
}
static ssize_t resolution_store(struct device *device,
struct device_attribute *attr, const char *buf, size_t size)
{
struct w1_slave *sl = dev_to_w1_slave(device);
int val;
int ret = 0;
ret = kstrtoint(buf, 10, &val); /* converting user entry to int */
if (ret) { /* conversion error */
dev_info(device,
"%s: conversion error. err= %d\n", __func__, ret);
return size; /* return size to avoid call back again */
}
if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
dev_info(device,
"%s: Device not supported by the driver\n", __func__);
return size; /* No device family */
}
/*
* Don't deal with the val enterd by user,
* only device knows what is correct or not
*/
/* get the correct function depending on the device */
ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val);
if (ret) {
dev_info(device,
"%s: writing error %d\n", __func__, ret);
/* return size to avoid call back again */
} else
SLAVE_RESOLUTION(sl) = val;
return size;
}
static ssize_t eeprom_store(struct device *device,
struct device_attribute *attr, const char *buf, size_t size)
{
struct w1_slave *sl = dev_to_w1_slave(device);
int ret = -EINVAL; /* Invalid argument */
if (size == sizeof(EEPROM_CMD_WRITE)) {
if (!strncmp(buf, EEPROM_CMD_WRITE, sizeof(EEPROM_CMD_WRITE)-1))
ret = copy_scratchpad(sl);
} else if (size == sizeof(EEPROM_CMD_READ)) {
if (!strncmp(buf, EEPROM_CMD_READ, sizeof(EEPROM_CMD_READ)-1))
ret = recall_eeprom(sl);
}
if (ret)
dev_info(device, "%s: error in process %d\n", __func__, ret);
return size;
}
static ssize_t alarms_show(struct device *device,
struct device_attribute *attr, char *buf)
{
struct w1_slave *sl = dev_to_w1_slave(device);
int ret;
s8 th = 0, tl = 0;
struct therm_info scratchpad;
ret = read_scratchpad(sl, &scratchpad);
if (!ret) {
th = scratchpad.rom[2]; /* TH is byte 2 */
tl = scratchpad.rom[3]; /* TL is byte 3 */
} else {
dev_info(device,
"%s: error reading alarms register %d\n",
__func__, ret);
}
return sprintf(buf, "%hd %hd\n", tl, th);
}
static ssize_t alarms_store(struct device *device,
struct device_attribute *attr, const char *buf, size_t size)
{
struct w1_slave *sl = dev_to_w1_slave(device);
struct therm_info info;
u8 new_config_register[3]; /* array of data to be written */
int temp, ret;
char *token = NULL;
s8 tl, th, tt; /* 1 byte per value + temp ring order */
char *p_args, *orig;
p_args = orig = kmalloc(size, GFP_KERNEL);
/* Safe string copys as buf is const */
if (!p_args) {
dev_warn(device,
"%s: error unable to allocate memory %d\n",
__func__, -ENOMEM);
return size;
}
strcpy(p_args, buf);
/* Split string using space char */
token = strsep(&p_args, " ");
if (!token) {
dev_info(device,
"%s: error parsing args %d\n", __func__, -EINVAL);
goto free_m;
}
/* Convert 1st entry to int */
ret = kstrtoint (token, 10, &temp);
if (ret) {
dev_info(device,
"%s: error parsing args %d\n", __func__, ret);
goto free_m;
}
tl = int_to_short(temp);
/* Split string using space char */
token = strsep(&p_args, " ");
if (!token) {
dev_info(device,
"%s: error parsing args %d\n", __func__, -EINVAL);
goto free_m;
}
/* Convert 2nd entry to int */
ret = kstrtoint (token, 10, &temp);
if (ret) {
dev_info(device,
"%s: error parsing args %d\n", __func__, ret);
goto free_m;
}
/* Prepare to cast to short by eliminating out of range values */
th = int_to_short(temp);
/* Reorder if required th and tl */
if (tl > th) {
tt = tl; tl = th; th = tt;
}
/*
* Read the scratchpad to change only the required bits
* (th : byte 2 - tl: byte 3)
*/
ret = read_scratchpad(sl, &info);
if (!ret) {
new_config_register[0] = th; /* Byte 2 */
new_config_register[1] = tl; /* Byte 3 */
new_config_register[2] = info.rom[4];/* Byte 4 */
} else {
dev_info(device,
"%s: error reading from the slave device %d\n",
__func__, ret);
goto free_m;
}
/* Write data in the device RAM */
if (!SLAVE_SPECIFIC_FUNC(sl)) {
dev_info(device,
"%s: Device not supported by the driver %d\n",
__func__, -ENODEV);
goto free_m;
}
ret = SLAVE_SPECIFIC_FUNC(sl)->write_data(sl, new_config_register);
if (ret)
dev_info(device,
"%s: error writing to the slave device %d\n",
__func__, ret);
free_m:
/* free allocated memory */
kfree(orig);
return size;
}
static ssize_t therm_bulk_read_store(struct device *device,
struct device_attribute *attr, const char *buf, size_t size)
{
struct w1_master *dev_master = dev_to_w1_master(device);
int ret = -EINVAL; /* Invalid argument */
if (size == sizeof(BULK_TRIGGER_CMD))
if (!strncmp(buf, BULK_TRIGGER_CMD,
sizeof(BULK_TRIGGER_CMD)-1))
ret = trigger_bulk_read(dev_master);
if (ret)
dev_info(device,
"%s: unable to trigger a bulk read on the bus. err=%d\n",
__func__, ret);
return size;
}
static ssize_t therm_bulk_read_show(struct device *device,
struct device_attribute *attr, char *buf)
{
struct w1_master *dev_master = dev_to_w1_master(device);
struct w1_slave *sl = NULL;
int ret = 0;
list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
if (sl->family_data) {
if (bulk_read_support(sl)) {
if (SLAVE_CONVERT_TRIGGERED(sl) == -1) {
ret = -1;
goto show_result;
}
if (SLAVE_CONVERT_TRIGGERED(sl) == 1)
/* continue to check other slaves */
ret = 1;
}
}
}
show_result:
return sprintf(buf, "%d\n", ret);
}
#if IS_REACHABLE(CONFIG_HWMON)
static int w1_read_temp(struct device *device, u32 attr, int channel,
long *val)
{
struct w1_slave *sl = dev_get_drvdata(device);
struct therm_info info;
int ret;
switch (attr) {
case hwmon_temp_input:
ret = convert_t(sl, &info);
if (ret)
return ret;
if (!info.verdict) {
ret = -EIO;
return ret;
}
*val = temperature_from_RAM(sl, info.rom);
ret = 0;
break;
default:
ret = -EOPNOTSUPP;
break;
}
return ret;
}
#endif
#define W1_42_CHAIN 0x99
#define W1_42_CHAIN_OFF 0x3C
#define W1_42_CHAIN_OFF_INV 0xC3
#define W1_42_CHAIN_ON 0x5A
#define W1_42_CHAIN_ON_INV 0xA5
#define W1_42_CHAIN_DONE 0x96
#define W1_42_CHAIN_DONE_INV 0x69
#define W1_42_COND_READ 0x0F
#define W1_42_SUCCESS_CONFIRM_BYTE 0xAA
#define W1_42_FINISHED_BYTE 0xFF
static ssize_t w1_seq_show(struct device *device,
struct device_attribute *attr, char *buf)
{
struct w1_slave *sl = dev_to_w1_slave(device);
ssize_t c = PAGE_SIZE;
int rv;
int i;
u8 ack;
u64 rn;
struct w1_reg_num *reg_num;
int seq = 0;
mutex_lock(&sl->master->bus_mutex);
/* Place all devices in CHAIN state */
if (w1_reset_bus(sl->master))
goto error;
w1_write_8(sl->master, W1_SKIP_ROM);
w1_write_8(sl->master, W1_42_CHAIN);
w1_write_8(sl->master, W1_42_CHAIN_ON);
w1_write_8(sl->master, W1_42_CHAIN_ON_INV);
msleep(sl->master->pullup_duration);
/* check for acknowledgment */
ack = w1_read_8(sl->master);
if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
goto error;
/* In case the bus fails to send 0xFF, limit */
for (i = 0; i <= 64; i++) {
if (w1_reset_bus(sl->master))
goto error;
w1_write_8(sl->master, W1_42_COND_READ);
rv = w1_read_block(sl->master, (u8 *)&rn, 8);
reg_num = (struct w1_reg_num *) &rn;
if (reg_num->family == W1_42_FINISHED_BYTE)
break;
if (sl->reg_num.id == reg_num->id)
seq = i;
w1_write_8(sl->master, W1_42_CHAIN);
w1_write_8(sl->master, W1_42_CHAIN_DONE);
w1_write_8(sl->master, W1_42_CHAIN_DONE_INV);
w1_read_block(sl->master, &ack, sizeof(ack));
/* check for acknowledgment */
ack = w1_read_8(sl->master);
if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
goto error;
}
/* Exit from CHAIN state */
if (w1_reset_bus(sl->master))
goto error;
w1_write_8(sl->master, W1_SKIP_ROM);
w1_write_8(sl->master, W1_42_CHAIN);
w1_write_8(sl->master, W1_42_CHAIN_OFF);
w1_write_8(sl->master, W1_42_CHAIN_OFF_INV);
/* check for acknowledgment */
ack = w1_read_8(sl->master);
if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
goto error;
mutex_unlock(&sl->master->bus_mutex);
c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", seq);
return PAGE_SIZE - c;
error:
mutex_unlock(&sl->master->bus_mutex);
return -EIO;
}
static int __init w1_therm_init(void)
{
int err, i;
for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
err = w1_register_family(w1_therm_families[i].f);
if (err)
w1_therm_families[i].broken = 1;
}
return 0;
}
static void __exit w1_therm_fini(void)
{
int i;
for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i)
if (!w1_therm_families[i].broken)
w1_unregister_family(w1_therm_families[i].f);
}
module_init(w1_therm_init);
module_exit(w1_therm_fini);
MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family.");
MODULE_LICENSE("GPL");
MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18S20));
MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1822));
MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18B20));
MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1825));
MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS28EA00));
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