diff options
Diffstat (limited to 'drivers/w1')
| -rw-r--r-- | drivers/w1/slaves/w1_therm.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c index 5a81ce2a4e74..825536196e61 100644 --- a/drivers/w1/slaves/w1_therm.c +++ b/drivers/w1/slaves/w1_therm.c @@ -58,6 +58,9 @@ module_param_named(strong_pullup, w1_strong_pullup, int, 0); #define EEPROM_CMD_WRITE "save" /* cmd for write eeprom sysfs */ #define EEPROM_CMD_READ "restore" /* cmd for read eeprom sysfs */ +#define MIN_TEMP -55 /* min temperature that can be mesured */ +#define MAX_TEMP 125 /* max temperature that can be mesured */ + /* Helpers Macros */ /* @@ -96,6 +99,7 @@ module_param_named(strong_pullup, w1_strong_pullup, int, 0); * @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) */ struct w1_therm_family_converter { u8 broken; @@ -105,6 +109,7 @@ struct w1_therm_family_converter { 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); }; /** @@ -239,6 +244,12 @@ static ssize_t resolution_store(struct device *device, 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); + /* Attributes declarations */ static DEVICE_ATTR_RW(w1_slave); @@ -247,6 +258,7 @@ 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); /* Interface Functions declaration */ @@ -278,6 +290,7 @@ static struct attribute *w1_therm_attrs[] = { &dev_attr_ext_power.attr, &dev_attr_resolution.attr, &dev_attr_eeprom.attr, + &dev_attr_alarms.attr, NULL, }; @@ -286,6 +299,7 @@ static struct attribute *w1_ds18s20_attrs[] = { &dev_attr_temperature.attr, &dev_attr_ext_power.attr, &dev_attr_eeprom.attr, + &dev_attr_alarms.attr, NULL, }; @@ -296,6 +310,7 @@ static struct attribute *w1_ds28ea00_attrs[] = { &dev_attr_ext_power.attr, &dev_attr_resolution.attr, &dev_attr_eeprom.attr, + &dev_attr_alarms.attr, NULL, }; @@ -556,6 +571,7 @@ static struct w1_therm_family_converter w1_therm_families[] = { .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, }, { .f = &w1_therm_family_DS1822, @@ -563,6 +579,7 @@ static struct w1_therm_family_converter w1_therm_families[] = { .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, }, { .f = &w1_therm_family_DS18B20, @@ -570,6 +587,7 @@ static struct w1_therm_family_converter w1_therm_families[] = { .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, }, { .f = &w1_therm_family_DS28EA00, @@ -577,6 +595,7 @@ static struct w1_therm_family_converter w1_therm_families[] = { .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, }, { .f = &w1_therm_family_DS1825, @@ -584,6 +603,7 @@ static struct w1_therm_family_converter w1_therm_families[] = { .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, } }; @@ -678,6 +698,26 @@ static inline int temperature_from_RAM(struct w1_slave *sl, u8 rom[9]) 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) @@ -1251,6 +1291,127 @@ static ssize_t eeprom_store(struct device *device, 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 = -ENODEV; + 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 = -EINVAL; + char *token = NULL; + s8 tl, th, tt; /* 1 byte per value + temp ring order */ + char *p_args = 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(p_args); + + return size; +} + #if IS_REACHABLE(CONFIG_HWMON) static int w1_read_temp(struct device *device, u32 attr, int channel, long *val) |