[PATCH AUTOSEL 4.4 075/174] hwmon: (w83627hf) Use request_muxed_region for Super-IO accesses

[PATCH AUTOSEL 4.4 075/174] hwmon: (w83627hf) Use request_muxed_region for Super-IO accesses

[Sasha Levin]

From: Guenter Roeck <linux@roeck-us.net>

[ Upstream commit e95fd518d05bfc087da6fcdea4900a57cfb083bd ]

Super-IO accesses may fail on a system with no or unmapped LPC bus.

Also, other drivers may attempt to access the LPC bus at the same time,
resulting in undefined behavior.

Use request_muxed_region() to ensure that IO access on the requested
address space is supported, and to ensure that access by multiple drivers
is synchronized.

Fixes: b72656dbc491 ("hwmon: (w83627hf) Stop using globals for I/O port numbers")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/hwmon/w83627hf.c | 42 +++++++++++++++++++++++++++++++++++-----
 1 file changed, 37 insertions(+), 5 deletions(-)

diff --git a/drivers/hwmon/w83627hf.c b/drivers/hwmon/w83627hf.c
index 721295b9a051..43c0f89cefdf 100644
--- a/drivers/hwmon/w83627hf.c
+++ b/drivers/hwmon/w83627hf.c
@@ -130,17 +130,23 @@ superio_select(struct w83627hf_sio_data *sio, int ld)
 	outb(ld,  sio->sioaddr + 1);
 }
 
-static inline void
+static inline int
 superio_enter(struct w83627hf_sio_data *sio)
 {
+	if (!request_muxed_region(sio->sioaddr, 2, DRVNAME))
+		return -EBUSY;
+
 	outb(0x87, sio->sioaddr);
 	outb(0x87, sio->sioaddr);
+
+	return 0;
 }
 
 static inline void
 superio_exit(struct w83627hf_sio_data *sio)
 {
 	outb(0xAA, sio->sioaddr);
+	release_region(sio->sioaddr, 2);
 }
 
 #define W627_DEVID 0x52
@@ -1275,7 +1281,7 @@ static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
 static int __init w83627hf_find(int sioaddr, unsigned short *addr,
 				struct w83627hf_sio_data *sio_data)
 {
-	int err = -ENODEV;
+	int err;
 	u16 val;
 
 	static __initconst char *const names[] = {
@@ -1287,7 +1293,11 @@ static int __init w83627hf_find(int sioaddr, unsigned short *addr,
 	};
 
 	sio_data->sioaddr = sioaddr;
-	superio_enter(sio_data);
+	err = superio_enter(sio_data);
+	if (err)
+		return err;
+
+	err = -ENODEV;
 	val = force_id ? force_id : superio_inb(sio_data, DEVID);
 	switch (val) {
 	case W627_DEVID:
@@ -1641,9 +1651,21 @@ static int w83627thf_read_gpio5(struct platform_device *pdev)
 	struct w83627hf_sio_data *sio_data = dev_get_platdata(&pdev->dev);
 	int res = 0xff, sel;
 
-	superio_enter(sio_data);
+	if (superio_enter(sio_data)) {
+		/*
+		 * Some other driver reserved the address space for itself.
+		 * We don't want to fail driver instantiation because of that,
+		 * so display a warning and keep going.
+		 */
+		dev_warn(&pdev->dev,
+			 "Can not read VID data: Failed to enable SuperIO access\n");
+		return res;
+	}
+
 	superio_select(sio_data, W83627HF_LD_GPIO5);
 
+	res = 0xff;
+
 	/* Make sure these GPIO pins are enabled */
 	if (!(superio_inb(sio_data, W83627THF_GPIO5_EN) & (1<<3))) {
 		dev_dbg(&pdev->dev, "GPIO5 disabled, no VID function\n");
@@ -1674,7 +1696,17 @@ static int w83687thf_read_vid(struct platform_device *pdev)
 	struct w83627hf_sio_data *sio_data = dev_get_platdata(&pdev->dev);
 	int res = 0xff;
 
-	superio_enter(sio_data);
+	if (superio_enter(sio_data)) {
+		/*
+		 * Some other driver reserved the address space for itself.
+		 * We don't want to fail driver instantiation because of that,
+		 * so display a warning and keep going.
+		 */
+		dev_warn(&pdev->dev,
+			 "Can not read VID data: Failed to enable SuperIO access\n");
+		return res;
+	}
+
 	superio_select(sio_data, W83627HF_LD_HWM);
 
 	/* Make sure these GPIO pins are enabled */
-- 
2.20.1

[PATCH AUTOSEL 4.4 136/174] hwmon: (shtc1) fix shtc1 and shtw1 id mask

[Sasha Levin]

From: Dan Robertson <dan@dlrobertson.com>

[ Upstream commit fdc7d8e829ec755c5cfb2f5a8d8c0cdfb664f895 ]

Fix an error in the bitmaskfor the shtc1 and shtw1 bitmask used to
retrieve the chip ID from the ID register. See section 5.7 of the shtw1
or shtc1 datasheet for details.

Fixes: 1a539d372edd9832444e7a3daa710c444c014dc9 ("hwmon: add support for Sensirion SHTC1 sensor")
Signed-off-by: Dan Robertson <dan@dlrobertson.com>
Link: https://lore.kernel.org/r/20190905014554.21658-3-dan@dlrobertson.com
[groeck: Reordered to be first in series and adjusted accordingly]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/hwmon/shtc1.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwmon/shtc1.c b/drivers/hwmon/shtc1.c
index decd7df995ab..2a18539591ea 100644
--- a/drivers/hwmon/shtc1.c
+++ b/drivers/hwmon/shtc1.c
@@ -38,7 +38,7 @@ static const unsigned char shtc1_cmd_read_id_reg[]	       = { 0xef, 0xc8 };
 
 /* constants for reading the ID register */
 #define SHTC1_ID	  0x07
-#define SHTC1_ID_REG_MASK 0x1f
+#define SHTC1_ID_REG_MASK 0x3f
 
 /* delays for non-blocking i2c commands, both in us */
 #define SHTC1_NONBLOCKING_WAIT_TIME_HPM  14400
-- 
2.20.1