1 files changed, 185 insertions, 101 deletions

diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c
index 1ba07b0833fa..5a81ce2a4e74 100644
--- a/drivers/w1/slaves/w1_therm.c
+++ b/drivers/w1/slaves/w1_therm.c
@@ -93,6 +93,7 @@ module_param_named(strong_pullup, w1_strong_pullup, int, 0);
  * @reserved: not used here
  * @f: pointer to the device binding structure
  * @convert: pointer to the device conversion function
+ * @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
  */
@@ -101,6 +102,7 @@ struct w1_therm_family_converter {
 	u16		reserved;
 	struct w1_family	*f;
 	int		(*convert)(u8 rom[9]);
+	int		(*get_conversion_time)(struct w1_slave *sl);
 	int		(*set_resolution)(struct w1_slave *sl, int val);
 	int		(*get_resolution)(struct w1_slave *sl);
 };
@@ -154,6 +156,15 @@ struct therm_info {
 static int reset_select_slave(struct w1_slave *sl);
 
 /**
+ * convert_t() - Query the device for temperature conversion and read
+ * @sl: pointer to the slave to read
+ * @info: pointer to a structure to store the read results
+ *
+ * Return: 0 if success, -kernel error code otherwise
+ */
+static int convert_t(struct w1_slave *sl, struct therm_info *info);
+
+/**
  * read_scratchpad() - read the data in device RAM
  * @sl: pointer to the slave to read
  * @info: pointer to a structure to store the read results
@@ -213,6 +224,9 @@ static ssize_t w1_slave_store(struct device *device,
 static ssize_t w1_seq_show(struct device *device,
 	struct device_attribute *attr, char *buf);
 
+static ssize_t temperature_show(struct device *device,
+	struct device_attribute *attr, char *buf);
+
 static ssize_t ext_power_show(struct device *device,
 	struct device_attribute *attr, char *buf);
 
@@ -229,6 +243,7 @@ static ssize_t eeprom_store(struct device *device,
 
 static DEVICE_ATTR_RW(w1_slave);
 static DEVICE_ATTR_RO(w1_seq);
+static DEVICE_ATTR_RO(temperature);
 static DEVICE_ATTR_RO(ext_power);
 static DEVICE_ATTR_RW(resolution);
 static DEVICE_ATTR_WO(eeprom);
@@ -259,6 +274,7 @@ static void w1_therm_remove_slave(struct w1_slave *sl);
 
 static struct attribute *w1_therm_attrs[] = {
 	&dev_attr_w1_slave.attr,
+	&dev_attr_temperature.attr,
 	&dev_attr_ext_power.attr,
 	&dev_attr_resolution.attr,
 	&dev_attr_eeprom.attr,
@@ -267,6 +283,7 @@ static struct attribute *w1_therm_attrs[] = {
 
 static struct attribute *w1_ds18s20_attrs[] = {
 	&dev_attr_w1_slave.attr,
+	&dev_attr_temperature.attr,
 	&dev_attr_ext_power.attr,
 	&dev_attr_eeprom.attr,
 	NULL,
@@ -275,6 +292,7 @@ static struct attribute *w1_ds18s20_attrs[] = {
 static struct attribute *w1_ds28ea00_attrs[] = {
 	&dev_attr_w1_slave.attr,
 	&dev_attr_w1_seq.attr,
+	&dev_attr_temperature.attr,
 	&dev_attr_ext_power.attr,
 	&dev_attr_resolution.attr,
 	&dev_attr_eeprom.attr,
@@ -389,6 +407,37 @@ static struct w1_family w1_therm_family_DS1825 = {
 
 /* Device dependent func */
 
+static inline int w1_DS18B20_convert_time(struct w1_slave *sl)
+{
+	int ret;
+
+	if (!sl->family_data)
+		return -ENODEV;	/* device unknown */
+
+	/* return time in ms for conversion operation */
+	switch (SLAVE_RESOLUTION(sl)) {
+	case 9:
+		ret = 95;
+		break;
+	case 10:
+		ret = 190;
+		break;
+	case 11:
+		ret = 375;
+		break;
+	case 12:
+	default:
+		ret = 750;
+	}
+	return ret;
+}
+
+static inline int w1_DS18S20_convert_time(struct w1_slave *sl)
+{
+	(void)(sl);
+	return 750; /* always 750ms for DS18S20 */
+}
+
 static inline int w1_DS18B20_write_data(struct w1_slave *sl,
 				const u8 *data)
 {
@@ -480,8 +529,10 @@ static inline int w1_DS18S20_convert_temp(u8 rom[9])
 {
 	int t, h;
 
-	if (!rom[7])
+	if (!rom[7]) {
+		pr_debug("%s: Invalid argument for conversion\n", __func__);
 		return 0;
+	}
 
 	if (rom[1] == 0)
 		t = ((s32)rom[0] >> 1)*1000;
@@ -500,34 +551,39 @@ 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,
-		.set_resolution	= NULL,	/* no config register */
-		.get_resolution	= NULL,	/* no config register */
+		.f				= &w1_therm_family_DS18S20,
+		.convert			= w1_DS18S20_convert_temp,
+		.get_conversion_time	= w1_DS18S20_convert_time,
+		.set_resolution		= NULL,	/* no config register */
+		.get_resolution		= NULL,	/* no config register */
 	},
 	{
-		.f		= &w1_therm_family_DS1822,
-		.convert	= w1_DS18B20_convert_temp,
-		.set_resolution	= w1_DS18B20_set_resolution,
-		.get_resolution	= w1_DS18B20_get_resolution,
+		.f				= &w1_therm_family_DS1822,
+		.convert			= w1_DS18B20_convert_temp,
+		.get_conversion_time	= w1_DS18B20_convert_time,
+		.set_resolution		= w1_DS18B20_set_resolution,
+		.get_resolution		= w1_DS18B20_get_resolution,
 	},
 	{
-		.f		= &w1_therm_family_DS18B20,
-		.convert	= w1_DS18B20_convert_temp,
-		.set_resolution	= w1_DS18B20_set_resolution,
-		.get_resolution	= w1_DS18B20_get_resolution,
+		.f				= &w1_therm_family_DS18B20,
+		.convert			= w1_DS18B20_convert_temp,
+		.get_conversion_time	= w1_DS18B20_convert_time,
+		.set_resolution		= w1_DS18B20_set_resolution,
+		.get_resolution		= w1_DS18B20_get_resolution,
 	},
 	{
-		.f		= &w1_therm_family_DS28EA00,
-		.convert	= w1_DS18B20_convert_temp,
-		.set_resolution	= w1_DS18B20_set_resolution,
-		.get_resolution	= w1_DS18B20_get_resolution,
+		.f				= &w1_therm_family_DS28EA00,
+		.convert			= w1_DS18B20_convert_temp,
+		.get_conversion_time	= w1_DS18B20_convert_time,
+		.set_resolution		= w1_DS18B20_set_resolution,
+		.get_resolution		= w1_DS18B20_get_resolution,
 	},
 	{
-		.f		= &w1_therm_family_DS1825,
-		.convert	= w1_DS18B20_convert_temp,
-		.set_resolution	= w1_DS18B20_set_resolution,
-		.get_resolution	= w1_DS18B20_get_resolution,
+		.f				= &w1_therm_family_DS1825,
+		.convert			= w1_DS18B20_convert_temp,
+		.get_conversion_time	= w1_DS18B20_convert_time,
+		.set_resolution		= w1_DS18B20_set_resolution,
+		.get_resolution		= w1_DS18B20_get_resolution,
 	}
 };
 
@@ -582,24 +638,44 @@ static inline bool bus_mutex_lock(struct mutex *lock)
 }
 
 /**
- * w1_convert_temp() - temperature conversion binding function
- * @rom: data read from device RAM (8 data bytes + 1 CRC byte)
- * @fid: device family id
+ * conversion_time() - get the Tconv for the slave
+ * @sl: device to get the conversion time
  *
- * The function call the temperature computation function according to
- * device family.
+ * On device supporting resolution settings, conversion time depend
+ * on the resolution setting. This helper function get the slave timing,
+ * depending on its current setting.
  *
- * Return: value in millidegrees Celsius.
+ * Return: conversion time in ms, negative values are kernel error code
  */
-static inline int w1_convert_temp(u8 rom[9], u8 fid)
+static inline int conversion_time(struct w1_slave *sl)
 {
-	int i;
+	if (SLAVE_SPECIFIC_FUNC(sl))
+		return SLAVE_SPECIFIC_FUNC(sl)->get_conversion_time(sl);
 
-	for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i)
-		if (w1_therm_families[i].f->fid == fid)
-			return w1_therm_families[i].convert(rom);
+	dev_info(&sl->dev,
+		"%s: Device not supported by the driver\n", __func__);
 
-	return 0;
+	return -ENODEV;  /* No device family */
+}
+
+/**
+ * temperature_from_RAM() - Convert the read info to temperature
+ * @sl: device that sent the RAM data
+ * @rom: read value on the slave device RAM
+ *
+ * Device dependent, the function bind the correct computation method.
+ *
+ * Return: temperature in 1/1000degC, 0 on error.
+ */
+static inline int temperature_from_RAM(struct w1_slave *sl, u8 rom[9])
+{
+	if (SLAVE_SPECIFIC_FUNC(sl))
+		return SLAVE_SPECIFIC_FUNC(sl)->convert(rom);
+
+	dev_info(&sl->dev,
+		"%s: Device not supported by the driver\n", __func__);
+
+	return 0;  /* No device family */
 }
 
 /* Interface Functions */
@@ -679,96 +755,74 @@ static int reset_select_slave(struct w1_slave *sl)
 	return 0;
 }
 
-static ssize_t read_therm(struct device *device,
-			  struct w1_slave *sl, struct therm_info *info)
+static int convert_t(struct w1_slave *sl, struct therm_info *info)
 {
-	struct w1_master *dev = sl->master;
-	u8 external_power;
-	int ret, max_trying = 10;
-	u8 *family_data = sl->family_data;
+	struct w1_master *dev_master = sl->master;
+	int max_trying = W1_THERM_MAX_TRY;
+	int t_conv;
+	int ret = -ENODEV;
+	bool strong_pullup;
 
-	if (!family_data) {
-		ret = -ENODEV;
+	if (!sl->family_data)
 		goto error;
-	}
 
-	/* prevent the slave from going away in sleep */
-	atomic_inc(THERM_REFCNT(family_data));
+	strong_pullup = (w1_strong_pullup == 2 ||
+					(!SLAVE_POWERMODE(sl) &&
+					w1_strong_pullup));
 
-	ret = mutex_lock_interruptible(&dev->bus_mutex);
-	if (ret != 0)
-		goto dec_refcnt;
+	/* get conversion duration device and id dependent */
+	t_conv = conversion_time(sl);
 
 	memset(info->rom, 0, sizeof(info->rom));
 
-	while (max_trying--) {
+	/* 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 count = 0;
-			unsigned int tm = 750;
 			unsigned long sleep_rem;
 
-			w1_write_8(dev, W1_READ_PSUPPLY);
-			external_power = w1_read_8(dev);
-
-			if (reset_select_slave(sl))
-				continue;
-
 			/* 750ms strong pullup (or delay) after the convert */
-			if (w1_strong_pullup == 2 ||
-					(!external_power && w1_strong_pullup))
-				w1_next_pullup(dev, tm);
-
-			w1_write_8(dev, W1_CONVERT_TEMP);
+			if (strong_pullup)
+				w1_next_pullup(dev_master, t_conv);
 
-			if (external_power) {
-				mutex_unlock(&dev->bus_mutex);
+			w1_write_8(dev_master, W1_CONVERT_TEMP);
 
-				sleep_rem = msleep_interruptible(tm);
+			if (strong_pullup) { /*some device need pullup */
+				sleep_rem = msleep_interruptible(t_conv);
 				if (sleep_rem != 0) {
 					ret = -EINTR;
-					goto dec_refcnt;
+					goto mt_unlock;
 				}
+				mutex_unlock(&dev_master->bus_mutex);
+			} else { /*no device need pullup */
+				mutex_unlock(&dev_master->bus_mutex);
 
-				ret = mutex_lock_interruptible(&dev->bus_mutex);
-				if (ret != 0)
-					goto dec_refcnt;
-			} else if (!w1_strong_pullup) {
-				sleep_rem = msleep_interruptible(tm);
+				sleep_rem = msleep_interruptible(t_conv);
 				if (sleep_rem != 0) {
 					ret = -EINTR;
-					goto mt_unlock;
-				}
-			}
-
-			if (!reset_select_slave(sl)) {
-
-				w1_write_8(dev, W1_READ_SCRATCHPAD);
-				count = w1_read_block(dev, info->rom, 9);
-				if (count != 9) {
-					dev_warn(device, "w1_read_block() "
-						"returned %u instead of 9.\n",
-						count);
+					goto dec_refcnt;
 				}
-
-				info->crc = w1_calc_crc8(info->rom, 8);
-
-				if (info->rom[8] == info->crc)
-					info->verdict = 1;
 			}
+			ret = read_scratchpad(sl, info);
+			goto dec_refcnt;
 		}
 
-		if (info->verdict)
-			break;
 	}
 
 mt_unlock:
-	mutex_unlock(&dev->bus_mutex);
+	mutex_unlock(&dev_master->bus_mutex);
 dec_refcnt:
-	atomic_dec(THERM_REFCNT(family_data));
+	atomic_dec(THERM_REFCNT(sl->family_data));
 error:
 	return ret;
 }
@@ -1000,27 +1054,33 @@ static ssize_t w1_slave_show(struct device *device,
 	u8 *family_data = sl->family_data;
 	int ret, i;
 	ssize_t c = PAGE_SIZE;
-	u8 fid = sl->family->fid;
 
-	ret = read_therm(device, sl, &info);
-	if (ret)
-		return ret;
+	ret = convert_t(sl, &info);
+
+	if (ret < 0) {
+		dev_dbg(device,
+			"%s: Temperature data may be corrupted. err=%d\n",
+			__func__, ret);
+		return 0;
+	}
 
 	for (i = 0; i < 9; ++i)
 		c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", info.rom[i]);
 	c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n",
 		      info.crc, (info.verdict) ? "YES" : "NO");
+
 	if (info.verdict)
 		memcpy(family_data, info.rom, sizeof(info.rom));
 	else
-		dev_warn(device, "Read failed CRC check\n");
+		dev_warn(device, "%s:Read failed CRC check\n", __func__);
 
 	for (i = 0; i < 9; ++i)
 		c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ",
 			      ((u8 *)family_data)[i]);
 
 	c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n",
-			w1_convert_temp(info.rom, fid));
+			temperature_from_RAM(sl, info.rom));
+
 	ret = PAGE_SIZE - c;
 	return ret;
 }
@@ -1063,6 +1123,31 @@ static ssize_t w1_slave_store(struct device *device,
 	return size; /* always return size to avoid infinite calling */
 }
 
+static ssize_t temperature_show(struct device *device,
+	struct device_attribute *attr, char *buf)
+{
+	struct w1_slave *sl = dev_to_w1_slave(device);
+	struct therm_info info;
+	int ret = 0;
+
+	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 */
+	}
+
+	ret = convert_t(sl, &info);
+
+	if (ret < 0) {
+		dev_dbg(device,
+			"%s: Temperature data may be corrupted. err=%d\n",
+			__func__, ret);
+		return 0;
+	}
+
+	return sprintf(buf, "%d\n", temperature_from_RAM(sl, info.rom));
+}
+
 static ssize_t ext_power_show(struct device *device,
 	struct device_attribute *attr, char *buf)
 {
@@ -1172,12 +1257,11 @@ static int w1_read_temp(struct device *device, u32 attr, int channel,
 {
 	struct w1_slave *sl = dev_get_drvdata(device);
 	struct therm_info info;
-	u8 fid = sl->family->fid;
 	int ret;
 
 	switch (attr) {
 	case hwmon_temp_input:
-		ret = read_therm(device, sl, &info);
+		ret = convert_t(sl, &info);
 		if (ret)
 			return ret;
 
@@ -1186,7 +1270,7 @@ static int w1_read_temp(struct device *device, u32 attr, int channel,
 			return ret;
 		}
 
-		*val = w1_convert_temp(info.rom, fid);
+		*val = temperature_from_RAM(sl, info.rom);
 		ret = 0;
 		break;
 	default: