Merge tag 'char-misc-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here is the big char/misc driver update for 4.14-rc1.

  Lots of different stuff in here, it's been an active development cycle
  for some reason. Highlights are:

   - updated binder driver, this brings binder up to date with what
     shipped in the Android O release, plus some more changes that
     happened since then that are in the Android development trees.

   - coresight updates and fixes

   - mux driver file renames to be a bit "nicer"

   - intel_th driver updates

   - normal set of hyper-v updates and changes

   - small fpga subsystem and driver updates

   - lots of const code changes all over the driver trees

   - extcon driver updates

   - fmc driver subsystem upadates

   - w1 subsystem minor reworks and new features and drivers added

   - spmi driver updates

  Plus a smattering of other minor driver updates and fixes.

  All of these have been in linux-next with no reported issues for a
  while"

* tag 'char-misc-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (244 commits)
  ANDROID: binder: don't queue async transactions to thread.
  ANDROID: binder: don't enqueue death notifications to thread todo.
  ANDROID: binder: Don't BUG_ON(!spin_is_locked()).
  ANDROID: binder: Add BINDER_GET_NODE_DEBUG_INFO ioctl
  ANDROID: binder: push new transactions to waiting threads.
  ANDROID: binder: remove proc waitqueue
  android: binder: Add page usage in binder stats
  android: binder: fixup crash introduced by moving buffer hdr
  drivers: w1: add hwmon temp support for w1_therm
  drivers: w1: refactor w1_slave_show to make the temp reading functionality separate
  drivers: w1: add hwmon support structures
  eeprom: idt_89hpesx: Support both ACPI and OF probing
  mcb: Fix an error handling path in 'chameleon_parse_cells()'
  MCB: add support for SC31 to mcb-lpc
  mux: make device_type const
  char: virtio: constify attribute_group structures.
  Documentation/ABI: document the nvmem sysfs files
  lkdtm: fix spelling mistake: "incremeted" -> "incremented"
  perf: cs-etm: Fix ETMv4 CONFIGR entry in perf.data file
  nvmem: include linux/err.h from header
  ...

5 files changed, 462 insertions, 33 deletions

diff --git a/drivers/w1/slaves/Kconfig b/drivers/w1/slaves/Kconfig
index fb68465908f2..bb4d7ed2ce55 100644
--- a/drivers/w1/slaves/Kconfig
+++ b/drivers/w1/slaves/Kconfig
@@ -65,6 +65,14 @@ config W1_SLAVE_DS2423
 	  Say Y here if you want to use a 1-wire
 	  counter family device (DS2423).
 
+config W1_SLAVE_DS2805
+	tristate "112-byte EEPROM support (DS28E05)"
+	help
+	  Say Y here if you want to use a 1-wire
+	  is a 112-byte user-programmable EEPROM is
+          organized as 7 pages of 16 bytes each with 64bit
+          unique number. Requires OverDrive Speed to talk to.
+
 config W1_SLAVE_DS2431
 	tristate "1kb EEPROM family support (DS2431)"
 	help
diff --git a/drivers/w1/slaves/Makefile b/drivers/w1/slaves/Makefile
index 54c63e420302..4622d8fed362 100644
--- a/drivers/w1/slaves/Makefile
+++ b/drivers/w1/slaves/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_W1_SLAVE_DS2413)	+= w1_ds2413.o
 obj-$(CONFIG_W1_SLAVE_DS2406)	+= w1_ds2406.o
 obj-$(CONFIG_W1_SLAVE_DS2423)	+= w1_ds2423.o
 obj-$(CONFIG_W1_SLAVE_DS2431)	+= w1_ds2431.o
+obj-$(CONFIG_W1_SLAVE_DS2805)	+= w1_ds2805.o
 obj-$(CONFIG_W1_SLAVE_DS2433)	+= w1_ds2433.o
 obj-$(CONFIG_W1_SLAVE_DS2438)	+= w1_ds2438.o
 obj-$(CONFIG_W1_SLAVE_DS2760)	+= w1_ds2760.o
diff --git a/drivers/w1/slaves/w1_ds2438.c b/drivers/w1/slaves/w1_ds2438.c
index 6487fb772a20..bf641a191d07 100644
--- a/drivers/w1/slaves/w1_ds2438.c
+++ b/drivers/w1/slaves/w1_ds2438.c
@@ -51,7 +51,7 @@
 #define DS2438_CURRENT_MSB		0x06
 #define DS2438_THRESHOLD		0x07
 
-int w1_ds2438_get_page(struct w1_slave *sl, int pageno, u8 *buf)
+static int w1_ds2438_get_page(struct w1_slave *sl, int pageno, u8 *buf)
 {
 	unsigned int retries = W1_DS2438_RETRIES;
 	u8 w1_buf[2];
@@ -85,7 +85,7 @@ int w1_ds2438_get_page(struct w1_slave *sl, int pageno, u8 *buf)
 	return -1;
 }
 
-int w1_ds2438_get_temperature(struct w1_slave *sl, int16_t *temperature)
+static int w1_ds2438_get_temperature(struct w1_slave *sl, int16_t *temperature)
 {
 	unsigned int retries = W1_DS2438_RETRIES;
 	u8 w1_buf[DS2438_PAGE_SIZE + 1 /*for CRC*/];
@@ -127,7 +127,7 @@ post_unlock:
 	return ret;
 }
 
-int w1_ds2438_change_config_bit(struct w1_slave *sl, u8 mask, u8 value)
+static int w1_ds2438_change_config_bit(struct w1_slave *sl, u8 mask, u8 value)
 {
 	unsigned int retries = W1_DS2438_RETRIES;
 	u8 w1_buf[3];
@@ -186,7 +186,8 @@ int w1_ds2438_change_config_bit(struct w1_slave *sl, u8 mask, u8 value)
 	return -1;
 }
 
-uint16_t w1_ds2438_get_voltage(struct w1_slave *sl, int adc_input, uint16_t *voltage)
+static uint16_t w1_ds2438_get_voltage(struct w1_slave *sl,
+				      int adc_input, uint16_t *voltage)
 {
 	unsigned int retries = W1_DS2438_RETRIES;
 	u8 w1_buf[DS2438_PAGE_SIZE + 1 /*for CRC*/];
diff --git a/drivers/w1/slaves/w1_ds2805.c b/drivers/w1/slaves/w1_ds2805.c
new file mode 100644
index 000000000000..29348d283a65
--- /dev/null
+++ b/drivers/w1/slaves/w1_ds2805.c
@@ -0,0 +1,313 @@
+/*
+ * w1_ds2805 - w1 family 0d (DS28E05) driver
+ *
+ * Copyright (c) 2016 Andrew Worsley amworsley@gmail.com
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2. See the file COPYING for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/device.h>
+#include <linux/types.h>
+#include <linux/delay.h>
+
+#include <linux/w1.h>
+
+#define W1_EEPROM_DS2805       0x0D
+
+#define W1_F0D_EEPROM_SIZE		128
+#define W1_F0D_PAGE_BITS		3
+#define W1_F0D_PAGE_SIZE		(1<<W1_F0D_PAGE_BITS)
+#define W1_F0D_PAGE_MASK		0x0F
+
+#define W1_F0D_SCRATCH_BITS  1
+#define W1_F0D_SCRATCH_SIZE  (1<<W1_F0D_SCRATCH_BITS)
+#define W1_F0D_SCRATCH_MASK  (W1_F0D_SCRATCH_SIZE-1)
+
+#define W1_F0D_READ_EEPROM	0xF0
+#define W1_F0D_WRITE_EEPROM	0x55
+#define W1_F0D_RELEASE		0xFF
+
+#define W1_F0D_CS_OK		0xAA /* Chip Status Ok */
+
+#define W1_F0D_TPROG_MS		16
+
+#define W1_F0D_READ_RETRIES		10
+#define W1_F0D_READ_MAXLEN		W1_F0D_EEPROM_SIZE
+
+/*
+ * Check the file size bounds and adjusts count as needed.
+ * This would not be needed if the file size didn't reset to 0 after a write.
+ */
+static inline size_t w1_f0d_fix_count(loff_t off, size_t count, size_t size)
+{
+	if (off > size)
+		return 0;
+
+	if ((off + count) > size)
+		return size - off;
+
+	return count;
+}
+
+/*
+ * Read a block from W1 ROM two times and compares the results.
+ * If they are equal they are returned, otherwise the read
+ * is repeated W1_F0D_READ_RETRIES times.
+ *
+ * count must not exceed W1_F0D_READ_MAXLEN.
+ */
+static int w1_f0d_readblock(struct w1_slave *sl, int off, int count, char *buf)
+{
+	u8 wrbuf[3];
+	u8 cmp[W1_F0D_READ_MAXLEN];
+	int tries = W1_F0D_READ_RETRIES;
+
+	do {
+		wrbuf[0] = W1_F0D_READ_EEPROM;
+		wrbuf[1] = off & 0x7f;
+		wrbuf[2] = 0;
+
+		if (w1_reset_select_slave(sl))
+			return -1;
+
+		w1_write_block(sl->master, wrbuf, sizeof(wrbuf));
+		w1_read_block(sl->master, buf, count);
+
+		if (w1_reset_select_slave(sl))
+			return -1;
+
+		w1_write_block(sl->master, wrbuf, sizeof(wrbuf));
+		w1_read_block(sl->master, cmp, count);
+
+		if (!memcmp(cmp, buf, count))
+			return 0;
+	} while (--tries);
+
+	dev_err(&sl->dev, "proof reading failed %d times\n",
+			W1_F0D_READ_RETRIES);
+
+	return -1;
+}
+
+static ssize_t w1_f0d_read_bin(struct file *filp, struct kobject *kobj,
+			       struct bin_attribute *bin_attr,
+			       char *buf, loff_t off, size_t count)
+{
+	struct w1_slave *sl = kobj_to_w1_slave(kobj);
+	int todo = count;
+
+	count = w1_f0d_fix_count(off, count, W1_F0D_EEPROM_SIZE);
+	if (count == 0)
+		return 0;
+
+	mutex_lock(&sl->master->mutex);
+
+	/* read directly from the EEPROM in chunks of W1_F0D_READ_MAXLEN */
+	while (todo > 0) {
+		int block_read;
+
+		if (todo >= W1_F0D_READ_MAXLEN)
+			block_read = W1_F0D_READ_MAXLEN;
+		else
+			block_read = todo;
+
+		if (w1_f0d_readblock(sl, off, block_read, buf) < 0) {
+			count = -EIO;
+			break;
+		}
+
+		todo -= W1_F0D_READ_MAXLEN;
+		buf += W1_F0D_READ_MAXLEN;
+		off += W1_F0D_READ_MAXLEN;
+	}
+
+	mutex_unlock(&sl->master->mutex);
+
+	return count;
+}
+
+/*
+ * Writes to the scratchpad and reads it back for verification.
+ * Then copies the scratchpad to EEPROM.
+ * The data must be aligned at W1_F0D_SCRATCH_SIZE bytes and
+ * must be W1_F0D_SCRATCH_SIZE bytes long.
+ * The master must be locked.
+ *
+ * @param sl	The slave structure
+ * @param addr	Address for the write
+ * @param len   length must be <= (W1_F0D_PAGE_SIZE - (addr & W1_F0D_PAGE_MASK))
+ * @param data	The data to write
+ * @return	0=Success -1=failure
+ */
+static int w1_f0d_write(struct w1_slave *sl, int addr, int len, const u8 *data)
+{
+	int tries = W1_F0D_READ_RETRIES;
+	u8 wrbuf[3];
+	u8 rdbuf[W1_F0D_SCRATCH_SIZE];
+	u8 cs;
+
+	if ((addr & 1) || (len != 2)) {
+		dev_err(&sl->dev, "%s: bad addr/len -  addr=%#x len=%d\n",
+		    __func__, addr, len);
+		return -1;
+	}
+
+retry:
+
+	/* Write the data to the scratchpad */
+	if (w1_reset_select_slave(sl))
+		return -1;
+
+	wrbuf[0] = W1_F0D_WRITE_EEPROM;
+	wrbuf[1] = addr & 0xff;
+	wrbuf[2] = 0xff; /* ?? from Example */
+
+	w1_write_block(sl->master, wrbuf, sizeof(wrbuf));
+	w1_write_block(sl->master, data, len);
+
+	w1_read_block(sl->master, rdbuf, sizeof(rdbuf));
+	/* Compare what was read against the data written */
+	if ((rdbuf[0] != data[0]) || (rdbuf[1] != data[1])) {
+
+		if (--tries)
+			goto retry;
+
+		dev_err(&sl->dev,
+			"could not write to eeprom, scratchpad compare failed %d times\n",
+			W1_F0D_READ_RETRIES);
+		pr_info("%s: rdbuf = %#x %#x data = %#x %#x\n",
+		    __func__, rdbuf[0], rdbuf[1], data[0], data[1]);
+
+		return -1;
+	}
+
+	/* Trigger write out to EEPROM */
+	w1_write_8(sl->master, W1_F0D_RELEASE);
+
+	/* Sleep for tprog ms to wait for the write to complete */
+	msleep(W1_F0D_TPROG_MS);
+
+	/* Check CS (Command Status) == 0xAA ? */
+	cs = w1_read_8(sl->master);
+	if (cs != W1_F0D_CS_OK) {
+		dev_err(&sl->dev, "save to eeprom failed = CS=%#x\n", cs);
+		return -1;
+	}
+
+	return 0;
+}
+
+static ssize_t w1_f0d_write_bin(struct file *filp, struct kobject *kobj,
+				struct bin_attribute *bin_attr,
+				char *buf, loff_t off, size_t count)
+{
+	struct w1_slave *sl = kobj_to_w1_slave(kobj);
+	int addr, len;
+	int copy;
+
+	count = w1_f0d_fix_count(off, count, W1_F0D_EEPROM_SIZE);
+	if (count == 0)
+		return 0;
+
+	mutex_lock(&sl->master->mutex);
+
+	/* Can only write data in blocks of the size of the scratchpad */
+	addr = off;
+	len = count;
+	while (len > 0) {
+
+		/* if len too short or addr not aligned */
+		if (len < W1_F0D_SCRATCH_SIZE || addr & W1_F0D_SCRATCH_MASK) {
+			char tmp[W1_F0D_SCRATCH_SIZE];
+
+			/* read the block and update the parts to be written */
+			if (w1_f0d_readblock(sl, addr & ~W1_F0D_SCRATCH_MASK,
+					W1_F0D_SCRATCH_SIZE, tmp)) {
+				count = -EIO;
+				goto out_up;
+			}
+
+			/* copy at most to the boundary of the PAGE or len */
+			copy = W1_F0D_SCRATCH_SIZE -
+				(addr & W1_F0D_SCRATCH_MASK);
+
+			if (copy > len)
+				copy = len;
+
+			memcpy(&tmp[addr & W1_F0D_SCRATCH_MASK], buf, copy);
+			if (w1_f0d_write(sl, addr & ~W1_F0D_SCRATCH_MASK,
+					W1_F0D_SCRATCH_SIZE, tmp) < 0) {
+				count = -EIO;
+				goto out_up;
+			}
+		} else {
+
+			copy = W1_F0D_SCRATCH_SIZE;
+			if (w1_f0d_write(sl, addr, copy, buf) < 0) {
+				count = -EIO;
+				goto out_up;
+			}
+		}
+		buf += copy;
+		addr += copy;
+		len -= copy;
+	}
+
+out_up:
+	mutex_unlock(&sl->master->mutex);
+
+	return count;
+}
+
+static struct bin_attribute w1_f0d_bin_attr = {
+	.attr = {
+		.name = "eeprom",
+		.mode = S_IRUGO | S_IWUSR,
+	},
+	.size = W1_F0D_EEPROM_SIZE,
+	.read = w1_f0d_read_bin,
+	.write = w1_f0d_write_bin,
+};
+
+static int w1_f0d_add_slave(struct w1_slave *sl)
+{
+	return sysfs_create_bin_file(&sl->dev.kobj, &w1_f0d_bin_attr);
+}
+
+static void w1_f0d_remove_slave(struct w1_slave *sl)
+{
+	sysfs_remove_bin_file(&sl->dev.kobj, &w1_f0d_bin_attr);
+}
+
+static struct w1_family_ops w1_f0d_fops = {
+	.add_slave      = w1_f0d_add_slave,
+	.remove_slave   = w1_f0d_remove_slave,
+};
+
+static struct w1_family w1_family_2d = {
+	.fid = W1_EEPROM_DS2805,
+	.fops = &w1_f0d_fops,
+};
+
+static int __init w1_f0d_init(void)
+{
+	pr_info("%s()\n", __func__);
+	return w1_register_family(&w1_family_2d);
+}
+
+static void __exit w1_f0d_fini(void)
+{
+	pr_info("%s()\n", __func__);
+	w1_unregister_family(&w1_family_2d);
+}
+
+module_init(w1_f0d_init);
+module_exit(w1_f0d_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Andrew Worsley amworsley@gmail.com");
+MODULE_DESCRIPTION("w1 family 0d driver for DS2805, 1kb EEPROM");
diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c
index cb3fc3c6b0d1..259525c3382a 100644
--- a/drivers/w1/slaves/w1_therm.c
+++ b/drivers/w1/slaves/w1_therm.c
@@ -29,6 +29,7 @@
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
+#include <linux/hwmon.h>
 
 #include <linux/w1.h>
 
@@ -59,6 +60,12 @@ struct w1_therm_family_data {
 	atomic_t refcnt;
 };
 
+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)
@@ -107,19 +114,72 @@ static struct attribute *w1_ds28ea00_attrs[] = {
 	&dev_attr_w1_seq.attr,
 	NULL,
 };
+
 ATTRIBUTE_GROUPS(w1_therm);
 ATTRIBUTE_GROUPS(w1_ds28ea00);
 
+#if IS_REACHABLE(CONFIG_HWMON)
+static int w1_read_temp(struct device *dev, u32 attr, int channel,
+			long *val);
+
+static umode_t w1_is_visible(const void *_data, enum hwmon_sensor_types type,
+			     u32 attr, int channel)
+{
+	return attr == hwmon_temp_input ? 0444 : 0;
+}
+
+static int w1_read(struct device *dev, enum hwmon_sensor_types type,
+		   u32 attr, int channel, long *val)
+{
+	switch (type) {
+	case hwmon_temp:
+		return w1_read_temp(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static const u32 w1_temp_config[] = {
+	HWMON_T_INPUT,
+	0
+};
+
+static const struct hwmon_channel_info w1_temp = {
+	.type = hwmon_temp,
+	.config = w1_temp_config,
+};
+
+static const struct hwmon_channel_info *w1_info[] = {
+	&w1_temp,
+	NULL
+};
+
+static const struct hwmon_ops w1_hwmon_ops = {
+	.is_visible = w1_is_visible,
+	.read = w1_read,
+};
+
+static const struct hwmon_chip_info w1_chip_info = {
+	.ops = &w1_hwmon_ops,
+	.info = w1_info,
+};
+#define W1_CHIPINFO	(&w1_chip_info)
+#else
+#define W1_CHIPINFO	NULL
+#endif
+
 static struct w1_family_ops w1_therm_fops = {
 	.add_slave	= w1_therm_add_slave,
 	.remove_slave	= w1_therm_remove_slave,
 	.groups		= w1_therm_groups,
+	.chip_info	= W1_CHIPINFO,
 };
 
 static struct w1_family_ops w1_ds28ea00_fops = {
 	.add_slave	= w1_therm_add_slave,
 	.remove_slave	= w1_therm_remove_slave,
 	.groups		= w1_ds28ea00_groups,
+	.chip_info	= W1_CHIPINFO,
 };
 
 static struct w1_family w1_therm_family_DS18S20 = {
@@ -422,33 +482,31 @@ static ssize_t w1_slave_store(struct device *device,
 	return ret ? : size;
 }
 
-static ssize_t w1_slave_show(struct device *device,
-	struct device_attribute *attr, char *buf)
+static ssize_t read_therm(struct device *device,
+			  struct w1_slave *sl, struct therm_info *info)
 {
-	struct w1_slave *sl = dev_to_w1_slave(device);
 	struct w1_master *dev = sl->master;
-	u8 rom[9], crc, verdict, external_power;
-	int i, ret, max_trying = 10;
-	ssize_t c = PAGE_SIZE;
+	u8 external_power;
+	int ret, max_trying = 10;
 	u8 *family_data = sl->family_data;
 
 	ret = mutex_lock_interruptible(&dev->bus_mutex);
 	if (ret != 0)
-		goto post_unlock;
+		goto error;
 
-	if (!sl->family_data) {
+	if (!family_data) {
 		ret = -ENODEV;
-		goto pre_unlock;
+		goto mt_unlock;
 	}
 
 	/* prevent the slave from going away in sleep */
 	atomic_inc(THERM_REFCNT(family_data));
-	memset(rom, 0, sizeof(rom));
+	memset(info->rom, 0, sizeof(info->rom));
 
 	while (max_trying--) {
 
-		verdict = 0;
-		crc = 0;
+		info->verdict = 0;
+		info->crc = 0;
 
 		if (!w1_reset_select_slave(sl)) {
 			int count = 0;
@@ -474,47 +532,69 @@ static ssize_t w1_slave_show(struct device *device,
 				sleep_rem = msleep_interruptible(tm);
 				if (sleep_rem != 0) {
 					ret = -EINTR;
-					goto post_unlock;
+					goto dec_refcnt;
 				}
 
 				ret = mutex_lock_interruptible(&dev->bus_mutex);
 				if (ret != 0)
-					goto post_unlock;
+					goto dec_refcnt;
 			} else if (!w1_strong_pullup) {
 				sleep_rem = msleep_interruptible(tm);
 				if (sleep_rem != 0) {
 					ret = -EINTR;
-					goto pre_unlock;
+					goto dec_refcnt;
 				}
 			}
 
 			if (!w1_reset_select_slave(sl)) {
 
 				w1_write_8(dev, W1_READ_SCRATCHPAD);
-				count = w1_read_block(dev, rom, 9);
+				count = w1_read_block(dev, info->rom, 9);
 				if (count != 9) {
 					dev_warn(device, "w1_read_block() "
 						"returned %u instead of 9.\n",
 						count);
 				}
 
-				crc = w1_calc_crc8(rom, 8);
+				info->crc = w1_calc_crc8(info->rom, 8);
 
-				if (rom[8] == crc)
-					verdict = 1;
+				if (info->rom[8] == info->crc)
+					info->verdict = 1;
 			}
 		}
 
-		if (verdict)
+		if (info->verdict)
 			break;
 	}
 
+dec_refcnt:
+	atomic_dec(THERM_REFCNT(family_data));
+mt_unlock:
+	mutex_unlock(&dev->bus_mutex);
+error:
+	return ret;
+}
+
+static ssize_t w1_slave_show(struct device *device,
+			     struct device_attribute *attr, char *buf)
+{
+	struct w1_slave *sl = dev_to_w1_slave(device);
+	struct therm_info info;
+	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;
+
 	for (i = 0; i < 9; ++i)
-		c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", rom[i]);
+		c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", info.rom[i]);
 	c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n",
-		      crc, (verdict) ? "YES" : "NO");
-	if (verdict)
-		memcpy(family_data, rom, sizeof(rom));
+		      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");
 
@@ -523,16 +603,42 @@ static ssize_t w1_slave_show(struct device *device,
 			      ((u8 *)family_data)[i]);
 
 	c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n",
-		w1_convert_temp(rom, sl->family->fid));
+			w1_convert_temp(info.rom, fid));
 	ret = PAGE_SIZE - c;
+	return ret;
+}
 
-pre_unlock:
-	mutex_unlock(&dev->bus_mutex);
+#if IS_REACHABLE(CONFIG_HWMON)
+static int w1_read_temp(struct device *device, u32 attr, int channel,
+			long *val)
+{
+	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);
+		if (ret)
+			return ret;
+
+		if (!info.verdict) {
+			ret = -EIO;
+			return ret;
+		}
+
+		*val = w1_convert_temp(info.rom, fid);
+		ret = 0;
+		break;
+	default:
+		ret = -EOPNOTSUPP;
+		break;
+	}
 
-post_unlock:
-	atomic_dec(THERM_REFCNT(family_data));
 	return ret;
 }
+#endif
 
 #define W1_42_CHAIN	0x99
 #define W1_42_CHAIN_OFF	0x3C