w1_therm: adding code comments and code reordering
Adding code comments to split code in dedicated parts. After the global declarations (defines, macros and function declarations), code is organized as follow : - Device and family dependent structures and functions - Interfaces functions - Helpers functions - Hardware functions - Sysfs interface functions Signed-off-by: Akira Shimahara <akira215corp@gmail.com> Link: https://lore.kernel.org/r/20200511203535.409599-1-akira215corp@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Akira Shimahara
Greg Kroah-Hartman
parent
691e0f2c74
commit
92b8d27244
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@ -25,7 +25,8 @@
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#define W1_THERM_DS1825 0x3B
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#define W1_THERM_DS28EA00 0x42
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/* Allow the strong pullup to be disabled, but default to enabled.
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/*
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* Allow the strong pullup to be disabled, but default to enabled.
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* If it was disabled a parasite powered device might not get the require
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* current to do a temperature conversion. If it is enabled parasite powered
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* devices have a better chance of getting the current required.
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@ -41,42 +42,55 @@
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static int w1_strong_pullup = 1;
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module_param_named(strong_pullup, w1_strong_pullup, int, 0);
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/* Helpers Macros */
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/* return the address of the refcnt in the family data */
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#define THERM_REFCNT(family_data) \
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(&((struct w1_therm_family_data *)family_data)->refcnt)
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/* Structs definition */
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/**
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* struct w1_therm_family_converter - bind device specific functions
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* @broken: flag for non-registred families
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* @reserved: not used here
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* @f: pointer to the device binding structure
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* @convert: pointer to the device conversion function
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* @precision: pointer to the device precision function
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* @eeprom: pointer to eeprom function
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*/
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struct w1_therm_family_converter {
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u8 broken;
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u16 reserved;
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struct w1_family *f;
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int (*convert)(u8 rom[9]);
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int (*precision)(struct device *device, int val);
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int (*eeprom)(struct device *device);
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};
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/**
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* struct w1_therm_family_data - device data
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* @rom: ROM device id (64bit Lasered ROM code + 1 CRC byte)
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* @refcnt: ref count
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*/
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struct w1_therm_family_data {
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uint8_t rom[9];
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atomic_t refcnt;
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};
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/**
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* struct therm_info - store temperature reading
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* @rom: read device data (8 data bytes + 1 CRC byte)
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* @crc: computed crc from rom
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* @verdict: 1 crc checked, 0 crc not matching
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*/
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struct therm_info {
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u8 rom[9];
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u8 crc;
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u8 verdict;
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};
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/* return the address of the refcnt in the family data */
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#define THERM_REFCNT(family_data) \
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(&((struct w1_therm_family_data *)family_data)->refcnt)
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static int w1_therm_add_slave(struct w1_slave *sl)
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{
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sl->family_data = kzalloc(sizeof(struct w1_therm_family_data),
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GFP_KERNEL);
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if (!sl->family_data)
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return -ENOMEM;
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atomic_set(THERM_REFCNT(sl->family_data), 1);
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return 0;
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}
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static void w1_therm_remove_slave(struct w1_slave *sl)
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{
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int refcnt = atomic_sub_return(1, THERM_REFCNT(sl->family_data));
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while (refcnt) {
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msleep(1000);
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refcnt = atomic_read(THERM_REFCNT(sl->family_data));
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}
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kfree(sl->family_data);
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sl->family_data = NULL;
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}
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/* Sysfs interface declaration */
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static ssize_t w1_slave_show(struct device *device,
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struct device_attribute *attr, char *buf);
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@ -87,9 +101,35 @@ static ssize_t w1_slave_store(struct device *device,
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static ssize_t w1_seq_show(struct device *device,
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struct device_attribute *attr, char *buf);
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/* Attributes declarations */
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static DEVICE_ATTR_RW(w1_slave);
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static DEVICE_ATTR_RO(w1_seq);
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/* Interface Functions declaration */
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/**
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* w1_therm_add_slave() - Called when a new slave is discovered
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* @sl: slave just discovered by the master.
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*
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* Called by the master when the slave is discovered on the bus. Used to
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* initialize slave state before the beginning of any communication.
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*
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* Return: 0 - If success, negative kernel code otherwise
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*/
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static int w1_therm_add_slave(struct w1_slave *sl);
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/**
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* w1_therm_remove_slave() - Called when a slave is removed
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* @sl: slave to be removed.
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*
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* Called by the master when the slave is considered not to be on the bus
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* anymore. Used to free memory.
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*/
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static void w1_therm_remove_slave(struct w1_slave *sl);
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/* Family attributes */
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static struct attribute *w1_therm_attrs[] = {
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&dev_attr_w1_slave.attr,
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NULL,
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@ -101,6 +141,8 @@ static struct attribute *w1_ds28ea00_attrs[] = {
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NULL,
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};
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/* Attribute groups */
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ATTRIBUTE_GROUPS(w1_therm);
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ATTRIBUTE_GROUPS(w1_ds28ea00);
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@ -154,6 +196,8 @@ static const struct hwmon_chip_info w1_chip_info = {
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#define W1_CHIPINFO NULL
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#endif
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/* Family operations */
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static struct w1_family_ops w1_therm_fops = {
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.add_slave = w1_therm_add_slave,
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.remove_slave = w1_therm_remove_slave,
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@ -168,6 +212,8 @@ static struct w1_family_ops w1_ds28ea00_fops = {
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.chip_info = W1_CHIPINFO,
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};
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/* Family binding operations struct */
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static struct w1_family w1_therm_family_DS18S20 = {
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.fid = W1_THERM_DS18S20,
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.fops = &w1_therm_fops,
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@ -193,138 +239,18 @@ static struct w1_family w1_therm_family_DS1825 = {
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.fops = &w1_therm_fops,
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};
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struct w1_therm_family_converter {
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u8 broken;
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u16 reserved;
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struct w1_family *f;
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int (*convert)(u8 rom[9]);
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int (*precision)(struct device *device, int val);
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int (*eeprom)(struct device *device);
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};
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/* Device dependent func */
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/* write configuration to eeprom */
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static inline int w1_therm_eeprom(struct device *device);
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/* Set precision for conversion */
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static inline int w1_DS18B20_precision(struct device *device, int val);
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static inline int w1_DS18S20_precision(struct device *device, int val);
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/* The return value is millidegrees Centigrade. */
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static inline int w1_DS18B20_convert_temp(u8 rom[9]);
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static inline int w1_DS18S20_convert_temp(u8 rom[9]);
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static struct w1_therm_family_converter w1_therm_families[] = {
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{
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.f = &w1_therm_family_DS18S20,
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.convert = w1_DS18S20_convert_temp,
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.precision = w1_DS18S20_precision,
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.eeprom = w1_therm_eeprom
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},
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{
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.f = &w1_therm_family_DS1822,
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.convert = w1_DS18B20_convert_temp,
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.precision = w1_DS18S20_precision,
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.eeprom = w1_therm_eeprom
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},
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{
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.f = &w1_therm_family_DS18B20,
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.convert = w1_DS18B20_convert_temp,
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.precision = w1_DS18B20_precision,
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.eeprom = w1_therm_eeprom
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},
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{
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.f = &w1_therm_family_DS28EA00,
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.convert = w1_DS18B20_convert_temp,
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.precision = w1_DS18S20_precision,
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.eeprom = w1_therm_eeprom
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},
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{
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.f = &w1_therm_family_DS1825,
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.convert = w1_DS18B20_convert_temp,
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.precision = w1_DS18S20_precision,
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.eeprom = w1_therm_eeprom
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}
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};
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static inline int w1_therm_eeprom(struct device *device)
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{
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struct w1_slave *sl = dev_to_w1_slave(device);
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struct w1_master *dev = sl->master;
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u8 rom[9], external_power;
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int ret, max_trying = 10;
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u8 *family_data = sl->family_data;
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if (!sl->family_data) {
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ret = -ENODEV;
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goto error;
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}
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/* prevent the slave from going away in sleep */
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atomic_inc(THERM_REFCNT(family_data));
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ret = mutex_lock_interruptible(&dev->bus_mutex);
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if (ret != 0)
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goto dec_refcnt;
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memset(rom, 0, sizeof(rom));
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while (max_trying--) {
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if (!w1_reset_select_slave(sl)) {
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unsigned int tm = 10;
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unsigned long sleep_rem;
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/* check if in parasite mode */
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w1_write_8(dev, W1_READ_PSUPPLY);
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external_power = w1_read_8(dev);
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if (w1_reset_select_slave(sl))
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continue;
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/* 10ms strong pullup/delay after the copy command */
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if (w1_strong_pullup == 2 ||
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(!external_power && w1_strong_pullup))
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w1_next_pullup(dev, tm);
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w1_write_8(dev, W1_COPY_SCRATCHPAD);
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if (external_power) {
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mutex_unlock(&dev->bus_mutex);
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sleep_rem = msleep_interruptible(tm);
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if (sleep_rem != 0) {
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ret = -EINTR;
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goto dec_refcnt;
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}
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ret = mutex_lock_interruptible(&dev->bus_mutex);
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if (ret != 0)
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goto dec_refcnt;
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} else if (!w1_strong_pullup) {
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sleep_rem = msleep_interruptible(tm);
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if (sleep_rem != 0) {
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ret = -EINTR;
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goto mt_unlock;
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}
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}
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break;
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}
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}
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mt_unlock:
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mutex_unlock(&dev->bus_mutex);
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dec_refcnt:
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atomic_dec(THERM_REFCNT(family_data));
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error:
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return ret;
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}
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/* DS18S20 does not feature configuration register */
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static inline int w1_DS18S20_precision(struct device *device, int val)
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{
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return 0;
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}
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/* Set precision for conversion */
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static inline int w1_DS18B20_precision(struct device *device, int val)
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{
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struct w1_slave *sl = dev_to_w1_slave(device);
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@ -407,6 +333,14 @@ error:
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return ret;
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}
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/**
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* w1_DS18B20_convert_temp() - temperature computation for DS18B20
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* @rom: data read from device RAM (8 data bytes + 1 CRC byte)
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*
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* Can be called for any DS18B20 compliant device.
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*
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* Return: value in millidegrees Celsius.
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*/
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static inline int w1_DS18B20_convert_temp(u8 rom[9])
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{
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s16 t = le16_to_cpup((__le16 *)rom);
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@ -414,6 +348,14 @@ static inline int w1_DS18B20_convert_temp(u8 rom[9])
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return t*1000/16;
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}
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/**
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* w1_DS18S20_convert_temp() - temperature computation for DS18S20
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* @rom: data read from device RAM (8 data bytes + 1 CRC byte)
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*
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* Can be called for any DS18S20 compliant device.
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*
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* Return: value in millidegrees Celsius.
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*/
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static inline int w1_DS18S20_convert_temp(u8 rom[9])
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{
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int t, h;
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@ -434,6 +376,53 @@ static inline int w1_DS18S20_convert_temp(u8 rom[9])
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return t;
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}
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/* Device capability description */
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static struct w1_therm_family_converter w1_therm_families[] = {
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{
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.f = &w1_therm_family_DS18S20,
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.convert = w1_DS18S20_convert_temp,
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.precision = w1_DS18S20_precision,
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.eeprom = w1_therm_eeprom
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},
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{
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.f = &w1_therm_family_DS1822,
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.convert = w1_DS18B20_convert_temp,
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.precision = w1_DS18S20_precision,
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.eeprom = w1_therm_eeprom
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},
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{
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.f = &w1_therm_family_DS18B20,
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.convert = w1_DS18B20_convert_temp,
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.precision = w1_DS18B20_precision,
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.eeprom = w1_therm_eeprom
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},
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{
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.f = &w1_therm_family_DS28EA00,
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.convert = w1_DS18B20_convert_temp,
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.precision = w1_DS18S20_precision,
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.eeprom = w1_therm_eeprom
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},
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{
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.f = &w1_therm_family_DS1825,
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.convert = w1_DS18B20_convert_temp,
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.precision = w1_DS18S20_precision,
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.eeprom = w1_therm_eeprom
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}
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};
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/* Helpers Functions */
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/**
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* w1_convert_temp() - temperature conversion binding function
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* @rom: data read from device RAM (8 data bytes + 1 CRC byte)
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* @fid: device family id
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*
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* The function call the temperature computation function according to
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* device family.
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*
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* Return: value in millidegrees Celsius.
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*/
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static inline int w1_convert_temp(u8 rom[9], u8 fid)
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{
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int i;
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@ -445,31 +434,32 @@ static inline int w1_convert_temp(u8 rom[9], u8 fid)
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return 0;
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}
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static ssize_t w1_slave_store(struct device *device,
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struct device_attribute *attr, const char *buf,
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size_t size)
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/* Interface Functions */
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static int w1_therm_add_slave(struct w1_slave *sl)
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{
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int val, ret;
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struct w1_slave *sl = dev_to_w1_slave(device);
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int i;
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ret = kstrtoint(buf, 0, &val);
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if (ret)
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return ret;
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for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
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if (w1_therm_families[i].f->fid == sl->family->fid) {
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/* zero value indicates to write current configuration to eeprom */
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if (val == 0)
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ret = w1_therm_families[i].eeprom(device);
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else
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ret = w1_therm_families[i].precision(device, val);
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break;
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}
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}
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return ret ? : size;
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sl->family_data = kzalloc(sizeof(struct w1_therm_family_data),
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GFP_KERNEL);
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if (!sl->family_data)
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return -ENOMEM;
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atomic_set(THERM_REFCNT(sl->family_data), 1);
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return 0;
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}
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static void w1_therm_remove_slave(struct w1_slave *sl)
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{
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int refcnt = atomic_sub_return(1, THERM_REFCNT(sl->family_data));
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while (refcnt) {
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msleep(1000);
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refcnt = atomic_read(THERM_REFCNT(sl->family_data));
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}
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kfree(sl->family_data);
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sl->family_data = NULL;
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}
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/* Hardware Functions */
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static ssize_t read_therm(struct device *device,
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struct w1_slave *sl, struct therm_info *info)
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{
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@ -564,6 +554,81 @@ error:
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return ret;
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}
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static inline int w1_therm_eeprom(struct device *device)
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{
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struct w1_slave *sl = dev_to_w1_slave(device);
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struct w1_master *dev = sl->master;
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u8 rom[9], external_power;
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int ret, max_trying = 10;
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u8 *family_data = sl->family_data;
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if (!sl->family_data) {
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ret = -ENODEV;
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goto error;
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}
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/* prevent the slave from going away in sleep */
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atomic_inc(THERM_REFCNT(family_data));
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ret = mutex_lock_interruptible(&dev->bus_mutex);
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if (ret != 0)
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goto dec_refcnt;
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memset(rom, 0, sizeof(rom));
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while (max_trying--) {
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if (!w1_reset_select_slave(sl)) {
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unsigned int tm = 10;
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unsigned long sleep_rem;
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/* check if in parasite mode */
|
||||
w1_write_8(dev, W1_READ_PSUPPLY);
|
||||
external_power = w1_read_8(dev);
|
||||
|
||||
if (w1_reset_select_slave(sl))
|
||||
continue;
|
||||
|
||||
/* 10ms strong pullup/delay after the copy command */
|
||||
if (w1_strong_pullup == 2 ||
|
||||
(!external_power && w1_strong_pullup))
|
||||
w1_next_pullup(dev, tm);
|
||||
|
||||
w1_write_8(dev, W1_COPY_SCRATCHPAD);
|
||||
|
||||
if (external_power) {
|
||||
mutex_unlock(&dev->bus_mutex);
|
||||
|
||||
sleep_rem = msleep_interruptible(tm);
|
||||
if (sleep_rem != 0) {
|
||||
ret = -EINTR;
|
||||
goto dec_refcnt;
|
||||
}
|
||||
|
||||
ret = mutex_lock_interruptible(&dev->bus_mutex);
|
||||
if (ret != 0)
|
||||
goto dec_refcnt;
|
||||
} else if (!w1_strong_pullup) {
|
||||
sleep_rem = msleep_interruptible(tm);
|
||||
if (sleep_rem != 0) {
|
||||
ret = -EINTR;
|
||||
goto mt_unlock;
|
||||
}
|
||||
}
|
||||
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
mt_unlock:
|
||||
mutex_unlock(&dev->bus_mutex);
|
||||
dec_refcnt:
|
||||
atomic_dec(THERM_REFCNT(family_data));
|
||||
error:
|
||||
return ret;
|
||||
}
|
||||
|
||||
/* Sysfs Interface definition */
|
||||
|
||||
static ssize_t w1_slave_show(struct device *device,
|
||||
struct device_attribute *attr, char *buf)
|
||||
{
|
||||
|
|
@ -597,6 +662,32 @@ static ssize_t w1_slave_show(struct device *device,
|
|||
return ret;
|
||||
}
|
||||
|
||||
static ssize_t w1_slave_store(struct device *device,
|
||||
struct device_attribute *attr, const char *buf,
|
||||
size_t size)
|
||||
{
|
||||
int val, ret;
|
||||
struct w1_slave *sl = dev_to_w1_slave(device);
|
||||
int i;
|
||||
|
||||
ret = kstrtoint(buf, 0, &val);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
|
||||
if (w1_therm_families[i].f->fid == sl->family->fid) {
|
||||
/* zero value indicates to write current configuration to eeprom */
|
||||
if (val == 0)
|
||||
ret = w1_therm_families[i].eeprom(device);
|
||||
else
|
||||
ret = w1_therm_families[i].precision(device,
|
||||
val);
|
||||
break;
|
||||
}
|
||||
}
|
||||
return ret ? : size;
|
||||
}
|
||||
|
||||
#if IS_REACHABLE(CONFIG_HWMON)
|
||||
static int w1_read_temp(struct device *device, u32 attr, int channel,
|
||||
long *val)
|
||||
|
|
@ -666,7 +757,7 @@ static ssize_t w1_seq_show(struct device *device,
|
|||
if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
|
||||
goto error;
|
||||
|
||||
/* In case the bus fails to send 0xFF, limit*/
|
||||
/* In case the bus fails to send 0xFF, limit */
|
||||
for (i = 0; i <= 64; i++) {
|
||||
if (w1_reset_bus(sl->master))
|
||||
goto error;
|
||||
|
|
|
|||
Loading…
Reference in New Issue