diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/w1/slaves/w1_therm.c | 357 |
1 files changed, 331 insertions, 26 deletions
diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c index c1b4eda16719..9b2d96335a70 100644 --- a/drivers/w1/slaves/w1_therm.c +++ b/drivers/w1/slaves/w1_therm.c @@ -17,6 +17,7 @@ #include <linux/delay.h> #include <linux/hwmon.h> #include <linux/string.h> +#include <linux/jiffies.h> #include <linux/w1.h> @@ -65,6 +66,20 @@ static u16 bulk_read_device_counter; /* =0 as per C standard */ #define MIN_TEMP -55 /* min temperature that can be mesured */ #define MAX_TEMP 125 /* max temperature that can be mesured */ +/* Allowed values for sysfs conv_time attribute */ +#define CONV_TIME_DEFAULT 0 +#define CONV_TIME_MEASURE 1 + +/* Bits in sysfs "features" value */ +#define W1_THERM_CHECK_RESULT 1 /* Enable conversion success check */ +#define W1_THERM_POLL_COMPLETION 2 /* Poll for conversion completion */ +#define W1_THERM_FEATURES_MASK 3 /* All values mask */ + +/* Poll period in milliseconds. Should be less then a shortest operation on the device */ +#define W1_POLL_PERIOD 32 +#define W1_POLL_CONVERT_TEMP 2000 /* Timeout for W1_CONVERT_TEMP, ms */ +#define W1_POLL_RECALL_EEPROM 500 /* Timeout for W1_RECALL_EEPROM, ms*/ + /* Helpers Macros */ /* @@ -89,6 +104,20 @@ static u16 bulk_read_device_counter; /* =0 as per C standard */ (((struct w1_therm_family_data *)(sl->family_data))->resolution) /* + * return the conv_time_override of the sl slave + * always test family data existence before using this macro + */ + #define SLAVE_CONV_TIME_OVERRIDE(sl) \ + (((struct w1_therm_family_data *)(sl->family_data))->conv_time_override) + +/* + * return the features of the sl slave + * always test family data existence before using this macro + */ + #define SLAVE_FEATURES(sl) \ + (((struct w1_therm_family_data *)(sl->family_data))->features) + +/* * return whether or not a converT command has been issued to the slave * * 0: no bulk read is pending * * -1: conversion is in progress @@ -136,6 +165,8 @@ struct w1_therm_family_converter { * -x error or undefined * @resolution: current device resolution * @convert_triggered: conversion state of the device + * @conv_time_override: user selected conversion time or CONV_TIME_DEFAULT + * @features: bit mask - enable temperature validity check, poll for completion * @specific_functions: pointer to struct of device specific function */ struct w1_therm_family_data { @@ -144,6 +175,8 @@ struct w1_therm_family_data { int external_powered; int resolution; int convert_triggered; + int conv_time_override; + unsigned int features; struct w1_therm_family_converter *specific_functions; }; @@ -285,6 +318,19 @@ static ssize_t therm_bulk_read_store(struct device *device, static ssize_t therm_bulk_read_show(struct device *device, struct device_attribute *attr, char *buf); +static ssize_t conv_time_show(struct device *device, + struct device_attribute *attr, char *buf); + +static ssize_t conv_time_store(struct device *device, + struct device_attribute *attr, const char *buf, + size_t size); + +static ssize_t features_show(struct device *device, + struct device_attribute *attr, char *buf); + +static ssize_t features_store(struct device *device, + struct device_attribute *attr, const char *buf, + size_t size); /* Attributes declarations */ static DEVICE_ATTR_RW(w1_slave); @@ -294,6 +340,8 @@ 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(conv_time); +static DEVICE_ATTR_RW(features); static DEVICE_ATTR_RW(therm_bulk_read); /* attribut at master level */ @@ -328,6 +376,8 @@ static struct attribute *w1_therm_attrs[] = { &dev_attr_resolution.attr, &dev_attr_eeprom.attr, &dev_attr_alarms.attr, + &dev_attr_conv_time.attr, + &dev_attr_features.attr, NULL, }; @@ -337,6 +387,8 @@ static struct attribute *w1_ds18s20_attrs[] = { &dev_attr_ext_power.attr, &dev_attr_eeprom.attr, &dev_attr_alarms.attr, + &dev_attr_conv_time.attr, + &dev_attr_features.attr, NULL, }; @@ -348,6 +400,8 @@ static struct attribute *w1_ds28ea00_attrs[] = { &dev_attr_resolution.attr, &dev_attr_eeprom.attr, &dev_attr_alarms.attr, + &dev_attr_conv_time.attr, + &dev_attr_features.attr, NULL, }; @@ -466,7 +520,10 @@ static inline int w1_DS18B20_convert_time(struct w1_slave *sl) if (!sl->family_data) return -ENODEV; /* device unknown */ - /* return time in ms for conversion operation */ + if (SLAVE_CONV_TIME_OVERRIDE(sl) != CONV_TIME_DEFAULT) + return SLAVE_CONV_TIME_OVERRIDE(sl); + + /* Return the conversion time from datasheet, depending on resolution */ switch (SLAVE_RESOLUTION(sl)) { case 9: ret = 95; @@ -486,8 +543,13 @@ static inline int w1_DS18B20_convert_time(struct w1_slave *sl) static inline int w1_DS18S20_convert_time(struct w1_slave *sl) { - (void)(sl); - return 750; /* always 750ms for DS18S20 */ + if (!sl->family_data) + return -ENODEV; /* device unknown */ + + if (SLAVE_CONV_TIME_OVERRIDE(sl) == CONV_TIME_DEFAULT) + return 750; /* default for DS18S20 */ + else + return SLAVE_CONV_TIME_OVERRIDE(sl); } static inline int w1_DS18B20_write_data(struct w1_slave *sl, @@ -507,7 +569,7 @@ 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; + struct therm_info info, info2; /* resolution of DS18B20 is in the range [9..12] bits */ if (val < 9 || val > 12) @@ -532,8 +594,18 @@ static inline int w1_DS18B20_set_resolution(struct w1_slave *sl, int val) /* Write data in the device RAM */ ret = w1_DS18B20_write_data(sl, new_config_register); + if (ret) + return ret; - return ret; + /* Some DS18B20 clones don't support resolution change, read back to verify */ + ret = read_scratchpad(sl, &info2); + if (ret) + return ret; + + if ((info2.rom[4] & 0x9F) == (info.rom[4] & 0x9F)) + return 0; + else + return -EIO; } static inline int w1_DS18B20_get_resolution(struct w1_slave *sl) @@ -700,6 +772,22 @@ static inline bool bus_mutex_lock(struct mutex *lock) } /** + * check_family_data() - Check if family data and specific functions are present + * @sl: W1 device data + * + * Return: 0 - OK, negative value - error + */ +static int check_family_data(struct w1_slave *sl) +{ + if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { + dev_info(&sl->dev, + "%s: Device is not supported by the driver\n", __func__); + return -EINVAL; /* No device family */ + } + return 0; +} + +/** * support_bulk_read() - check if slave support bulk read * @sl: device to check the ability * @@ -883,6 +971,34 @@ static int reset_select_slave(struct w1_slave *sl) return 0; } +/** + * w1_poll_completion - Poll for operation completion, with timeout + * @dev_master: the device master of the bus + * @tout_ms: timeout in milliseconds + * + * The device is answering 0's while an operation is in progress and 1's after it completes + * Timeout may happen if the previous command was not recognised due to a line noise + * + * Return: 0 - OK, negative error - timeout + */ +int w1_poll_completion(struct w1_master *dev_master, int tout_ms) +{ + int i; + + for (i = 0; i < tout_ms/W1_POLL_PERIOD; i++) { + /* Delay is before poll, for device to recognize a command */ + msleep(W1_POLL_PERIOD); + + /* Compare all 8 bits to mitigate a noise on the bus */ + if (w1_read_8(dev_master) == 0xFF) + break; + } + if (i == tout_ms/W1_POLL_PERIOD) + return -EIO; + + return 0; +} + static int convert_t(struct w1_slave *sl, struct therm_info *info) { struct w1_master *dev_master = sl->master; @@ -898,6 +1014,13 @@ static int convert_t(struct w1_slave *sl, struct therm_info *info) (!SLAVE_POWERMODE(sl) && w1_strong_pullup)); + if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) { + dev_warn(&sl->dev, + "%s: Disabling W1_THERM_POLL_COMPLETION in parasite power mode.\n", + __func__); + SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION; + } + /* get conversion duration device and id dependent */ t_conv = conversion_time(sl); @@ -933,15 +1056,38 @@ static int convert_t(struct w1_slave *sl, struct therm_info *info) } 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; + if (SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) { + ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP); + if (ret) { + dev_dbg(&sl->dev, "%s: Timeout\n", __func__); + goto mt_unlock; + } + mutex_unlock(&dev_master->bus_mutex); + } else { + /* Fixed delay */ + 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); + + /* If enabled, check for conversion success */ + if ((SLAVE_FEATURES(sl) & W1_THERM_CHECK_RESULT) && + (info->rom[6] == 0xC) && + ((info->rom[1] == 0x5 && info->rom[0] == 0x50) || + (info->rom[1] == 0x7 && info->rom[0] == 0xFF)) + ) { + /* Invalid reading (scratchpad byte 6 = 0xC) + * due to insufficient conversion time + * or power failure. + */ + ret = -EIO; + } + goto dec_refcnt; } @@ -955,6 +1101,76 @@ error: return ret; } +static int conv_time_measure(struct w1_slave *sl, int *conv_time) +{ + struct therm_info inf, + *info = &inf; + struct w1_master *dev_master = sl->master; + int max_trying = W1_THERM_MAX_TRY; + int ret = -ENODEV; + bool strong_pullup; + + if (!sl->family_data) + goto error; + + strong_pullup = (w1_strong_pullup == 2 || + (!SLAVE_POWERMODE(sl) && + w1_strong_pullup)); + + if (strong_pullup) { + pr_info("%s: Measure with strong_pullup is not supported.\n", __func__); + return -EINVAL; + } + + 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)) { + int j_start, j_end; + + /*no device need pullup */ + w1_write_8(dev_master, W1_CONVERT_TEMP); + + j_start = jiffies; + ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP); + if (ret) { + dev_dbg(&sl->dev, "%s: Timeout\n", __func__); + goto mt_unlock; + } + j_end = jiffies; + /* 1.2x increase for variation and changes over temperature range */ + *conv_time = jiffies_to_msecs(j_end-j_start)*12/10; + pr_debug("W1 Measure complete, conv_time = %d, HZ=%d.\n", + *conv_time, HZ); + if (*conv_time <= CONV_TIME_MEASURE) { + ret = -EIO; + goto mt_unlock; + } + mutex_unlock(&dev_master->bus_mutex); + 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; @@ -1118,10 +1334,7 @@ static int recall_eeprom(struct w1_slave *sl) 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); + ret = w1_poll_completion(dev_master, W1_POLL_RECALL_EEPROM); } } @@ -1345,11 +1558,13 @@ static ssize_t w1_slave_store(struct device *device, } if (ret) { - dev_info(device, - "%s: writing error %d\n", __func__, ret); - /* return size to avoid call back again */ - } else - SLAVE_RESOLUTION(sl) = val; + dev_warn(device, "%s: Set resolution - error %d\n", __func__, ret); + /* Propagate error to userspace */ + return ret; + } + SLAVE_RESOLUTION(sl) = val; + /* Reset the conversion time to default - it depends on resolution */ + SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT; return size; /* always return size to avoid infinite calling */ } @@ -1465,12 +1680,12 @@ static ssize_t resolution_store(struct device *device, /* 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; + if (ret) + return ret; + + SLAVE_RESOLUTION(sl) = val; + /* Reset the conversion time to default because it depends on resolution */ + SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT; return size; } @@ -1660,6 +1875,96 @@ show_result: return sprintf(buf, "%d\n", ret); } +static ssize_t conv_time_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 is not supported by the driver\n", __func__); + return 0; /* No device family */ + } + return sprintf(buf, "%d\n", conversion_time(sl)); +} + +static ssize_t conv_time_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); + + if (kstrtoint(buf, 10, &val)) /* converting user entry to int */ + return -EINVAL; + + if (check_family_data(sl)) + return -ENODEV; + + if (val != CONV_TIME_MEASURE) { + if (val >= CONV_TIME_DEFAULT) + SLAVE_CONV_TIME_OVERRIDE(sl) = val; + else + return -EINVAL; + + } else { + int conv_time; + + ret = conv_time_measure(sl, &conv_time); + if (ret) + return -EIO; + SLAVE_CONV_TIME_OVERRIDE(sl) = conv_time; + } + return size; +} + +static ssize_t features_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 */ + } + return sprintf(buf, "%u\n", SLAVE_FEATURES(sl)); +} + +static ssize_t features_store(struct device *device, + struct device_attribute *attr, const char *buf, size_t size) +{ + int val, ret = 0; + bool strong_pullup; + struct w1_slave *sl = dev_to_w1_slave(device); + + ret = kstrtouint(buf, 10, &val); /* converting user entry to int */ + if (ret) + return -EINVAL; /* invalid number */ + + if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { + dev_info(device, "%s: Device not supported by the driver\n", __func__); + return -ENODEV; + } + + if ((val & W1_THERM_FEATURES_MASK) != val) + return -EINVAL; + + SLAVE_FEATURES(sl) = val; + + strong_pullup = (w1_strong_pullup == 2 || + (!SLAVE_POWERMODE(sl) && + w1_strong_pullup)); + + if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) { + dev_warn(&sl->dev, + "%s: W1_THERM_POLL_COMPLETION disabled in parasite power mode.\n", + __func__); + SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION; + } + + return size; +} + #if IS_REACHABLE(CONFIG_HWMON) static int w1_read_temp(struct device *device, u32 attr, int channel, long *val) |