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Diffstat (limited to 'drivers/w1')
-rw-r--r--drivers/w1/slaves/w1_therm.c357
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)