diff options
| -rw-r--r-- | drivers/w1/slaves/w1_therm.c | 427 |
1 files changed, 259 insertions, 168 deletions
diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c index e028e0092799..1234916daaa8 100644 --- a/drivers/w1/slaves/w1_therm.c +++ b/drivers/w1/slaves/w1_therm.c @@ -25,7 +25,8 @@ #define W1_THERM_DS1825 0x3B #define W1_THERM_DS28EA00 0x42 -/* Allow the strong pullup to be disabled, but default to enabled. +/* + * 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. @@ -41,42 +42,55 @@ static int w1_strong_pullup = 1; module_param_named(strong_pullup, w1_strong_pullup, int, 0); +/* Helpers Macros */ + +/* 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 + * @precision: pointer to the device precision function + * @eeprom: pointer to eeprom function + */ +struct w1_therm_family_converter { + u8 broken; + u16 reserved; + struct w1_family *f; + int (*convert)(u8 rom[9]); + int (*precision)(struct device *device, int val); + int (*eeprom)(struct device *device); +}; + +/** + * struct w1_therm_family_data - device data + * @rom: ROM device id (64bit Lasered ROM code + 1 CRC byte) + * @refcnt: ref count + */ struct w1_therm_family_data { uint8_t rom[9]; atomic_t refcnt; }; +/** + * 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; }; -/* return the address of the refcnt in the family data */ -#define THERM_REFCNT(family_data) \ - (&((struct w1_therm_family_data *)family_data)->refcnt) - -static int w1_therm_add_slave(struct w1_slave *sl) -{ - 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); - return 0; -} - -static void w1_therm_remove_slave(struct w1_slave *sl) -{ - int refcnt = atomic_sub_return(1, THERM_REFCNT(sl->family_data)); - - while (refcnt) { - msleep(1000); - refcnt = atomic_read(THERM_REFCNT(sl->family_data)); - } - kfree(sl->family_data); - sl->family_data = NULL; -} +/* Sysfs interface declaration */ static ssize_t w1_slave_show(struct device *device, struct device_attribute *attr, char *buf); @@ -87,9 +101,35 @@ static ssize_t w1_slave_store(struct device *device, static ssize_t w1_seq_show(struct device *device, struct device_attribute *attr, char *buf); +/* Attributes declarations */ + static DEVICE_ATTR_RW(w1_slave); static DEVICE_ATTR_RO(w1_seq); +/* 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, NULL, @@ -101,6 +141,8 @@ static struct attribute *w1_ds28ea00_attrs[] = { NULL, }; +/* Attribute groups */ + ATTRIBUTE_GROUPS(w1_therm); ATTRIBUTE_GROUPS(w1_ds28ea00); @@ -154,6 +196,8 @@ static const struct hwmon_chip_info w1_chip_info = { #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, @@ -168,6 +212,8 @@ static struct w1_family_ops w1_ds28ea00_fops = { .chip_info = W1_CHIPINFO, }; +/* Family binding operations struct */ + static struct w1_family w1_therm_family_DS18S20 = { .fid = W1_THERM_DS18S20, .fops = &w1_therm_fops, @@ -193,138 +239,18 @@ static struct w1_family w1_therm_family_DS1825 = { .fops = &w1_therm_fops, }; -struct w1_therm_family_converter { - u8 broken; - u16 reserved; - struct w1_family *f; - int (*convert)(u8 rom[9]); - int (*precision)(struct device *device, int val); - int (*eeprom)(struct device *device); -}; +/* Device dependent func */ /* write configuration to eeprom */ static inline int w1_therm_eeprom(struct device *device); -/* Set precision for conversion */ -static inline int w1_DS18B20_precision(struct device *device, int val); -static inline int w1_DS18S20_precision(struct device *device, int val); - -/* The return value is millidegrees Centigrade. */ -static inline int w1_DS18B20_convert_temp(u8 rom[9]); -static inline int w1_DS18S20_convert_temp(u8 rom[9]); - -static struct w1_therm_family_converter w1_therm_families[] = { - { - .f = &w1_therm_family_DS18S20, - .convert = w1_DS18S20_convert_temp, - .precision = w1_DS18S20_precision, - .eeprom = w1_therm_eeprom - }, - { - .f = &w1_therm_family_DS1822, - .convert = w1_DS18B20_convert_temp, - .precision = w1_DS18S20_precision, - .eeprom = w1_therm_eeprom - }, - { - .f = &w1_therm_family_DS18B20, - .convert = w1_DS18B20_convert_temp, - .precision = w1_DS18B20_precision, - .eeprom = w1_therm_eeprom - }, - { - .f = &w1_therm_family_DS28EA00, - .convert = w1_DS18B20_convert_temp, - .precision = w1_DS18S20_precision, - .eeprom = w1_therm_eeprom - }, - { - .f = &w1_therm_family_DS1825, - .convert = w1_DS18B20_convert_temp, - .precision = w1_DS18S20_precision, - .eeprom = w1_therm_eeprom - } -}; - -static inline int w1_therm_eeprom(struct device *device) -{ - struct w1_slave *sl = dev_to_w1_slave(device); - struct w1_master *dev = sl->master; - u8 rom[9], external_power; - int ret, max_trying = 10; - u8 *family_data = sl->family_data; - - if (!sl->family_data) { - ret = -ENODEV; - goto error; - } - - /* prevent the slave from going away in sleep */ - atomic_inc(THERM_REFCNT(family_data)); - - ret = mutex_lock_interruptible(&dev->bus_mutex); - if (ret != 0) - goto dec_refcnt; - - memset(rom, 0, sizeof(rom)); - - while (max_trying--) { - if (!w1_reset_select_slave(sl)) { - unsigned int tm = 10; - unsigned long sleep_rem; - - /* 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; -} - /* DS18S20 does not feature configuration register */ static inline int w1_DS18S20_precision(struct device *device, int val) { return 0; } +/* Set precision for conversion */ static inline int w1_DS18B20_precision(struct device *device, int val) { struct w1_slave *sl = dev_to_w1_slave(device); @@ -407,6 +333,14 @@ error: 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); @@ -414,6 +348,14 @@ static inline int w1_DS18B20_convert_temp(u8 rom[9]) 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; @@ -434,6 +376,53 @@ static inline int w1_DS18S20_convert_temp(u8 rom[9]) return t; } +/* Device capability description */ + +static struct w1_therm_family_converter w1_therm_families[] = { + { + .f = &w1_therm_family_DS18S20, + .convert = w1_DS18S20_convert_temp, + .precision = w1_DS18S20_precision, + .eeprom = w1_therm_eeprom + }, + { + .f = &w1_therm_family_DS1822, + .convert = w1_DS18B20_convert_temp, + .precision = w1_DS18S20_precision, + .eeprom = w1_therm_eeprom + }, + { + .f = &w1_therm_family_DS18B20, + .convert = w1_DS18B20_convert_temp, + .precision = w1_DS18B20_precision, + .eeprom = w1_therm_eeprom + }, + { + .f = &w1_therm_family_DS28EA00, + .convert = w1_DS18B20_convert_temp, + .precision = w1_DS18S20_precision, + .eeprom = w1_therm_eeprom + }, + { + .f = &w1_therm_family_DS1825, + .convert = w1_DS18B20_convert_temp, + .precision = w1_DS18S20_precision, + .eeprom = w1_therm_eeprom + } +}; + +/* Helpers Functions */ + +/** + * w1_convert_temp() - temperature conversion binding function + * @rom: data read from device RAM (8 data bytes + 1 CRC byte) + * @fid: device family id + * + * The function call the temperature computation function according to + * device family. + * + * Return: value in millidegrees Celsius. + */ static inline int w1_convert_temp(u8 rom[9], u8 fid) { int i; @@ -445,31 +434,32 @@ static inline int w1_convert_temp(u8 rom[9], u8 fid) return 0; } -static ssize_t w1_slave_store(struct device *device, - struct device_attribute *attr, const char *buf, - size_t size) +/* Interface Functions */ + +static int w1_therm_add_slave(struct w1_slave *sl) { - int val, ret; - struct w1_slave *sl = dev_to_w1_slave(device); - int i; + 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); + return 0; +} - ret = kstrtoint(buf, 0, &val); - if (ret) - return ret; +static void w1_therm_remove_slave(struct w1_slave *sl) +{ + int refcnt = atomic_sub_return(1, THERM_REFCNT(sl->family_data)); - 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; - } + while (refcnt) { + msleep(1000); + refcnt = atomic_read(THERM_REFCNT(sl->family_data)); } - return ret ? : size; + kfree(sl->family_data); + sl->family_data = NULL; } +/* Hardware Functions */ + static ssize_t read_therm(struct device *device, struct w1_slave *sl, struct therm_info *info) { @@ -564,6 +554,81 @@ error: return ret; } +static inline int w1_therm_eeprom(struct device *device) +{ + struct w1_slave *sl = dev_to_w1_slave(device); + struct w1_master *dev = sl->master; + u8 rom[9], external_power; + int ret, max_trying = 10; + u8 *family_data = sl->family_data; + + if (!sl->family_data) { + ret = -ENODEV; + goto error; + } + + /* prevent the slave from going away in sleep */ + atomic_inc(THERM_REFCNT(family_data)); + + ret = mutex_lock_interruptible(&dev->bus_mutex); + if (ret != 0) + goto dec_refcnt; + + memset(rom, 0, sizeof(rom)); + + while (max_trying--) { + if (!w1_reset_select_slave(sl)) { + unsigned int tm = 10; + unsigned long sleep_rem; + + /* 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; |