[PATCH v2 0/3] I2C/SMBus: add support for Host Notify (in i2c_i801)

[PATCH v2 0/3] I2C/SMBus: add support for Host Notify (in i2c_i801)

[Benjamin Tissoires]

Hi,

this is a v2 of this patch series. Things are starting to shape better I think,
but I am still not sure about one or two things:
- do we want to #ifdef i2c_propagate_smbus_host_notify() so that we do not add
  a dependency in the KConfig for i2c_i801, or do actually want the dependency?
- do we want to have i2c_propagate_smbus_host_notify() to actually be able to
  sleep or do we prefer calling it directly a worker?

Note that I only compile-tested the ipmi_ssif changes, but this seems
straightforward enough.

Thanks for your inputs.

Cheers,
Benjamin

Benjamin Tissoires (3):
  i2c: add a protocol parameter to the alert callback
  i2c-smbus: add SMBus Host Notify support
  i2c: i801: add support of Host Notify

 Documentation/i2c/smbus-protocol |   3 +
 drivers/char/ipmi/ipmi_ssif.c    |   6 +-
 drivers/i2c/busses/i2c-i801.c    | 172 +++++++++++++++++++++++++++++----------
 drivers/i2c/i2c-smbus.c          |  35 +++++++-
 include/linux/i2c-smbus.h        |   8 ++
 include/linux/i2c.h              |  10 ++-
 include/uapi/linux/i2c.h         |   1 +
 7 files changed, 186 insertions(+), 49 deletions(-)

-- 
2.4.3

[PATCH v2 0/3] I2C/SMBus: add support for Host Notify (in i2c_i801)

[Benjamin Tissoires]

Hi,

this is a v2 of this patch series. Things are starting to shape better I think,
but I am still not sure about one or two things:
- do we want to #ifdef i2c_propagate_smbus_host_notify() so that we do not add
  a dependency in the KConfig for i2c_i801, or do actually want the dependency?
- do we want to have i2c_propagate_smbus_host_notify() to actually be able to
  sleep or do we prefer calling it directly a worker?

Note that I only compile-tested the ipmi_ssif changes, but this seems
straightforward enough.

Thanks for your inputs.

Cheers,
Benjamin

Benjamin Tissoires (3):
  i2c: add a protocol parameter to the alert callback
  i2c-smbus: add SMBus Host Notify support
  i2c: i801: add support of Host Notify

 Documentation/i2c/smbus-protocol |   3 +
 drivers/char/ipmi/ipmi_ssif.c    |   6 +-
 drivers/i2c/busses/i2c-i801.c    | 172 +++++++++++++++++++++++++++++----------
 drivers/i2c/i2c-smbus.c          |  35 +++++++-
 include/linux/i2c-smbus.h        |   8 ++
 include/linux/i2c.h              |  10 ++-
 include/uapi/linux/i2c.h         |   1 +
 7 files changed, 186 insertions(+), 49 deletions(-)

-- 
2.4.3

[PATCH v2 1/3] i2c: add a protocol parameter to the alert callback

[Benjamin Tissoires]

.alert() is meant to be generic, but there is currently no way
for the device driver to know which protocol generated the alert.
Add a parameter in .alert() to help the device driver to understand
what is given in data.

This patch is required to have the support of SMBus Host Notify protocol
through .alert().

Signed-off-by: Benjamin Tissoires <benjamin.tissoires-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---

New in v2

 drivers/char/ipmi/ipmi_ssif.c | 6 +++++-
 drivers/i2c/i2c-smbus.c       | 3 ++-
 include/linux/i2c.h           | 7 ++++++-
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c
index 207689c..1d4cece 100644
--- a/drivers/char/ipmi/ipmi_ssif.c
+++ b/drivers/char/ipmi/ipmi_ssif.c
@@ -567,12 +567,16 @@ static void retry_timeout(unsigned long data)
 }
 
 
-static void ssif_alert(struct i2c_client *client, unsigned int data)
+static void ssif_alert(struct i2c_client *client,
+		       enum i2c_alert_protocol protocol, unsigned int data)
 {
 	struct ssif_info *ssif_info = i2c_get_clientdata(client);
 	unsigned long oflags, *flags;
 	bool do_get = false;
 
+	if (protocol != I2C_PROTOCOL_SMBUS_ALERT)
+		return;
+
 	ssif_inc_stat(ssif_info, alerts);
 
 	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c
index 94765a8..abad351 100644
--- a/drivers/i2c/i2c-smbus.c
+++ b/drivers/i2c/i2c-smbus.c
@@ -56,7 +56,8 @@ static int smbus_do_alert(struct device *dev, void *addrp)
 	if (client->dev.driver) {
 		driver = to_i2c_driver(client->dev.driver);
 		if (driver->alert)
-			driver->alert(client, data->flag);
+			driver->alert(client, I2C_PROTOCOL_SMBUS_ALERT,
+				      data->flag);
 		else
 			dev_warn(&client->dev, "no driver alert()!\n");
 	} else
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index e83a738..6764734 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -123,6 +123,10 @@ extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
 					  const u8 *values);
 #endif /* I2C */
 
+enum i2c_alert_protocol {
+	I2C_PROTOCOL_SMBUS_ALERT,
+};
+
 /**
  * struct i2c_driver - represent an I2C device driver
  * @class: What kind of i2c device we instantiate (for detect)
@@ -178,7 +182,8 @@ struct i2c_driver {
 	 * For the SMBus alert protocol, there is a single bit of data passed
 	 * as the alert response's low bit ("event flag").
 	 */
-	void (*alert)(struct i2c_client *, unsigned int data);
+	void (*alert)(struct i2c_client *, enum i2c_alert_protocol protocol,
+		      unsigned int data);
 
 	/* a ioctl like command that can be used to perform specific functions
 	 * with the device.
-- 
2.4.3

[PATCH v2 1/3] i2c: add a protocol parameter to the alert callback

[Benjamin Tissoires]

.alert() is meant to be generic, but there is currently no way
for the device driver to know which protocol generated the alert.
Add a parameter in .alert() to help the device driver to understand
what is given in data.

This patch is required to have the support of SMBus Host Notify protocol
through .alert().

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
---

New in v2

 drivers/char/ipmi/ipmi_ssif.c | 6 +++++-
 drivers/i2c/i2c-smbus.c       | 3 ++-
 include/linux/i2c.h           | 7 ++++++-
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c
index 207689c..1d4cece 100644
--- a/drivers/char/ipmi/ipmi_ssif.c
+++ b/drivers/char/ipmi/ipmi_ssif.c
@@ -567,12 +567,16 @@ static void retry_timeout(unsigned long data)
 }
 
 
-static void ssif_alert(struct i2c_client *client, unsigned int data)
+static void ssif_alert(struct i2c_client *client,
+		       enum i2c_alert_protocol protocol, unsigned int data)
 {
 	struct ssif_info *ssif_info = i2c_get_clientdata(client);
 	unsigned long oflags, *flags;
 	bool do_get = false;
 
+	if (protocol != I2C_PROTOCOL_SMBUS_ALERT)
+		return;
+
 	ssif_inc_stat(ssif_info, alerts);
 
 	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c
index 94765a8..abad351 100644
--- a/drivers/i2c/i2c-smbus.c
+++ b/drivers/i2c/i2c-smbus.c
@@ -56,7 +56,8 @@ static int smbus_do_alert(struct device *dev, void *addrp)
 	if (client->dev.driver) {
 		driver = to_i2c_driver(client->dev.driver);
 		if (driver->alert)
-			driver->alert(client, data->flag);
+			driver->alert(client, I2C_PROTOCOL_SMBUS_ALERT,
+				      data->flag);
 		else
 			dev_warn(&client->dev, "no driver alert()!\n");
 	} else
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index e83a738..6764734 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -123,6 +123,10 @@ extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
 					  const u8 *values);
 #endif /* I2C */
 
+enum i2c_alert_protocol {
+	I2C_PROTOCOL_SMBUS_ALERT,
+};
+
 /**
  * struct i2c_driver - represent an I2C device driver
  * @class: What kind of i2c device we instantiate (for detect)
@@ -178,7 +182,8 @@ struct i2c_driver {
 	 * For the SMBus alert protocol, there is a single bit of data passed
 	 * as the alert response's low bit ("event flag").
 	 */
-	void (*alert)(struct i2c_client *, unsigned int data);
+	void (*alert)(struct i2c_client *, enum i2c_alert_protocol protocol,
+		      unsigned int data);
 
 	/* a ioctl like command that can be used to perform specific functions
 	 * with the device.
-- 
2.4.3

[PATCH v3 1/3] i2c: add a protocol parameter to the alert callback

[Benjamin Tissoires]

.alert() is meant to be generic, but there is currently no way
for the device driver to know which protocol generated the alert.
Add a parameter in .alert() to help the device driver to understand
what is given in data.

This patch is required to have the support of SMBus Host Notify protocol
through .alert().

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
---

Hi again,

of course, you send the patch series[1], switch to something else, and you realize
that you have a new warning...
Sorry, I missed the lm90 driver in the v2.

Adding also in CC the maintainers of LM90 and IPMI.

Cheers,
Benjamin

[1] http://marc.info/?l=linux-i2c&m=143646306528808&w=2

new in v2

changes in v3:
- added also lm90.c to support the new API

 drivers/char/ipmi/ipmi_ssif.c | 6 +++++-
 drivers/hwmon/lm90.c          | 3 ++-
 drivers/i2c/i2c-smbus.c       | 3 ++-
 include/linux/i2c.h           | 7 ++++++-
 4 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c
index 207689c..1d4cece 100644
--- a/drivers/char/ipmi/ipmi_ssif.c
+++ b/drivers/char/ipmi/ipmi_ssif.c
@@ -567,12 +567,16 @@ static void retry_timeout(unsigned long data)
 }
 
 
-static void ssif_alert(struct i2c_client *client, unsigned int data)
+static void ssif_alert(struct i2c_client *client,
+		       enum i2c_alert_protocol protocol, unsigned int data)
 {
 	struct ssif_info *ssif_info = i2c_get_clientdata(client);
 	unsigned long oflags, *flags;
 	bool do_get = false;
 
+	if (protocol != I2C_PROTOCOL_SMBUS_ALERT)
+		return;
+
 	ssif_inc_stat(ssif_info, alerts);
 
 	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index c9ff08d..2b77dbd 100644
--- a/drivers/hwmon/lm90.c
+++ b/drivers/hwmon/lm90.c
@@ -1624,7 +1624,8 @@ static int lm90_remove(struct i2c_client *client)
 	return 0;
 }
 
-static void lm90_alert(struct i2c_client *client, unsigned int flag)
+static void lm90_alert(struct i2c_client *client, enum i2c_alert_protocol type,
+		       unsigned int flag)
 {
 	u16 alarms;
 
diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c
index 94765a8..abad351 100644
--- a/drivers/i2c/i2c-smbus.c
+++ b/drivers/i2c/i2c-smbus.c
@@ -56,7 +56,8 @@ static int smbus_do_alert(struct device *dev, void *addrp)
 	if (client->dev.driver) {
 		driver = to_i2c_driver(client->dev.driver);
 		if (driver->alert)
-			driver->alert(client, data->flag);
+			driver->alert(client, I2C_PROTOCOL_SMBUS_ALERT,
+				      data->flag);
 		else
 			dev_warn(&client->dev, "no driver alert()!\n");
 	} else
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index e83a738..6764734 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -123,6 +123,10 @@ extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
 					  const u8 *values);
 #endif /* I2C */
 
+enum i2c_alert_protocol {
+	I2C_PROTOCOL_SMBUS_ALERT,
+};
+
 /**
  * struct i2c_driver - represent an I2C device driver
  * @class: What kind of i2c device we instantiate (for detect)
@@ -178,7 +182,8 @@ struct i2c_driver {
 	 * For the SMBus alert protocol, there is a single bit of data passed
 	 * as the alert response's low bit ("event flag").
 	 */
-	void (*alert)(struct i2c_client *, unsigned int data);
+	void (*alert)(struct i2c_client *, enum i2c_alert_protocol protocol,
+		      unsigned int data);
 
 	/* a ioctl like command that can be used to perform specific functions
 	 * with the device.
-- 
2.4.3

[lm-sensors] [PATCH v3 1/3] i2c: add a protocol parameter to the alert callback

[Benjamin Tissoires]

.alert() is meant to be generic, but there is currently no way
for the device driver to know which protocol generated the alert.
Add a parameter in .alert() to help the device driver to understand
what is given in data.

This patch is required to have the support of SMBus Host Notify protocol
through .alert().

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
---

Hi again,

of course, you send the patch series[1], switch to something else, and you realize
that you have a new warning...
Sorry, I missed the lm90 driver in the v2.

Adding also in CC the maintainers of LM90 and IPMI.

Cheers,
Benjamin

[1] http://marc.info/?l=linux-i2c&m\x143646306528808&w=2

new in v2

changes in v3:
- added also lm90.c to support the new API

 drivers/char/ipmi/ipmi_ssif.c | 6 +++++-
 drivers/hwmon/lm90.c          | 3 ++-
 drivers/i2c/i2c-smbus.c       | 3 ++-
 include/linux/i2c.h           | 7 ++++++-
 4 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c
index 207689c..1d4cece 100644
--- a/drivers/char/ipmi/ipmi_ssif.c
+++ b/drivers/char/ipmi/ipmi_ssif.c
@@ -567,12 +567,16 @@ static void retry_timeout(unsigned long data)
 }
 
 
-static void ssif_alert(struct i2c_client *client, unsigned int data)
+static void ssif_alert(struct i2c_client *client,
+		       enum i2c_alert_protocol protocol, unsigned int data)
 {
 	struct ssif_info *ssif_info = i2c_get_clientdata(client);
 	unsigned long oflags, *flags;
 	bool do_get = false;
 
+	if (protocol != I2C_PROTOCOL_SMBUS_ALERT)
+		return;
+
 	ssif_inc_stat(ssif_info, alerts);
 
 	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index c9ff08d..2b77dbd 100644
--- a/drivers/hwmon/lm90.c
+++ b/drivers/hwmon/lm90.c
@@ -1624,7 +1624,8 @@ static int lm90_remove(struct i2c_client *client)
 	return 0;
 }
 
-static void lm90_alert(struct i2c_client *client, unsigned int flag)
+static void lm90_alert(struct i2c_client *client, enum i2c_alert_protocol type,
+		       unsigned int flag)
 {
 	u16 alarms;
 
diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c
index 94765a8..abad351 100644
--- a/drivers/i2c/i2c-smbus.c
+++ b/drivers/i2c/i2c-smbus.c
@@ -56,7 +56,8 @@ static int smbus_do_alert(struct device *dev, void *addrp)
 	if (client->dev.driver) {
 		driver = to_i2c_driver(client->dev.driver);
 		if (driver->alert)
-			driver->alert(client, data->flag);
+			driver->alert(client, I2C_PROTOCOL_SMBUS_ALERT,
+				      data->flag);
 		else
 			dev_warn(&client->dev, "no driver alert()!\n");
 	} else
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index e83a738..6764734 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -123,6 +123,10 @@ extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
 					  const u8 *values);
 #endif /* I2C */
 
+enum i2c_alert_protocol {
+	I2C_PROTOCOL_SMBUS_ALERT,
+};
+
 /**
  * struct i2c_driver - represent an I2C device driver
  * @class: What kind of i2c device we instantiate (for detect)
@@ -178,7 +182,8 @@ struct i2c_driver {
 	 * For the SMBus alert protocol, there is a single bit of data passed
 	 * as the alert response's low bit ("event flag").
 	 */
-	void (*alert)(struct i2c_client *, unsigned int data);
+	void (*alert)(struct i2c_client *, enum i2c_alert_protocol protocol,
+		      unsigned int data);
 
 	/* a ioctl like command that can be used to perform specific functions
 	 * with the device.
-- 
2.4.3


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[PATCH v2 3/3] i2c: i801: add support of Host Notify

[Benjamin Tissoires]

The i801 chip can handle the Host Notify feature since ICH 3 as mentioned
in http://www.intel.com/content/dam/doc/datasheet/82801ca-io-controller-hub-3-datasheet.pdf

Enable the functionality unconditionally and propagate the alert
on each notification.

With a T440s and a Synaptics touchpad that implements Host Notify, the
payload data is always 0x0000, so I am not sure if the device actually
sends the payload or if there is a problem regarding the implementation.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---

Changes in v2:
- removed the description of the Slave functionality support in the chip table
  (the table shows what is supported, not what the hardware is capable of)
- use i2c-smbus to forward the notification
- remove the fifo, and directly retrieve the address and payload in the worker
- do not check for Host Notification is the feature is not enabled
- use inw_p() to read the payload instead of 2 inb_p() calls
- add /* fall-through */ comment
- unconditionally enable Host Notify if the hardware supports it (can be
  disabled by the user)

 drivers/i2c/busses/i2c-i801.c | 172 +++++++++++++++++++++++++++++++-----------
 1 file changed, 129 insertions(+), 43 deletions(-)

diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 5ecbb3f..f65f955 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -20,46 +20,46 @@
 /*
  * Supports the following Intel I/O Controller Hubs (ICH):
  *
- *					I/O			Block	I2C
- *					region	SMBus	Block	proc.	block
- * Chip name			PCI ID	size	PEC	buffer	call	read
- * ---------------------------------------------------------------------------
- * 82801AA (ICH)		0x2413	16	no	no	no	no
- * 82801AB (ICH0)		0x2423	16	no	no	no	no
- * 82801BA (ICH2)		0x2443	16	no	no	no	no
- * 82801CA (ICH3)		0x2483	32	soft	no	no	no
- * 82801DB (ICH4)		0x24c3	32	hard	yes	no	no
- * 82801E (ICH5)		0x24d3	32	hard	yes	yes	yes
- * 6300ESB			0x25a4	32	hard	yes	yes	yes
- * 82801F (ICH6)		0x266a	32	hard	yes	yes	yes
- * 6310ESB/6320ESB		0x269b	32	hard	yes	yes	yes
- * 82801G (ICH7)		0x27da	32	hard	yes	yes	yes
- * 82801H (ICH8)		0x283e	32	hard	yes	yes	yes
- * 82801I (ICH9)		0x2930	32	hard	yes	yes	yes
- * EP80579 (Tolapai)		0x5032	32	hard	yes	yes	yes
- * ICH10			0x3a30	32	hard	yes	yes	yes
- * ICH10			0x3a60	32	hard	yes	yes	yes
- * 5/3400 Series (PCH)		0x3b30	32	hard	yes	yes	yes
- * 6 Series (PCH)		0x1c22	32	hard	yes	yes	yes
- * Patsburg (PCH)		0x1d22	32	hard	yes	yes	yes
- * Patsburg (PCH) IDF		0x1d70	32	hard	yes	yes	yes
- * Patsburg (PCH) IDF		0x1d71	32	hard	yes	yes	yes
- * Patsburg (PCH) IDF		0x1d72	32	hard	yes	yes	yes
- * DH89xxCC (PCH)		0x2330	32	hard	yes	yes	yes
- * Panther Point (PCH)		0x1e22	32	hard	yes	yes	yes
- * Lynx Point (PCH)		0x8c22	32	hard	yes	yes	yes
- * Lynx Point-LP (PCH)		0x9c22	32	hard	yes	yes	yes
- * Avoton (SOC)			0x1f3c	32	hard	yes	yes	yes
- * Wellsburg (PCH)		0x8d22	32	hard	yes	yes	yes
- * Wellsburg (PCH) MS		0x8d7d	32	hard	yes	yes	yes
- * Wellsburg (PCH) MS		0x8d7e	32	hard	yes	yes	yes
- * Wellsburg (PCH) MS		0x8d7f	32	hard	yes	yes	yes
- * Coleto Creek (PCH)		0x23b0	32	hard	yes	yes	yes
- * Wildcat Point (PCH)		0x8ca2	32	hard	yes	yes	yes
- * Wildcat Point-LP (PCH)	0x9ca2	32	hard	yes	yes	yes
- * BayTrail (SOC)		0x0f12	32	hard	yes	yes	yes
- * Sunrise Point-H (PCH) 	0xa123  32	hard	yes	yes	yes
- * Sunrise Point-LP (PCH)	0x9d23	32	hard	yes	yes	yes
+ *					I/O	SMBus	Block	I2C
+ *					region	Host	SMBus	Block	proc.	block
+ * Chip name			PCI ID	size	notify	PEC	buffer	call	read
+ * ----------------------------------------------------------------------------------
+ * 82801AA (ICH)		0x2413	16	no	no	no	no	no
+ * 82801AB (ICH0)		0x2423	16	no	no	no	no	no
+ * 82801BA (ICH2)		0x2443	16	no	no	no	no	no
+ * 82801CA (ICH3)		0x2483	32	yes	soft	no	no	no
+ * 82801DB (ICH4)		0x24c3	32	yes	hard	yes	no	no
+ * 82801E (ICH5)		0x24d3	32	yes	hard	yes	yes	yes
+ * 6300ESB			0x25a4	32	yes	hard	yes	yes	yes
+ * 82801F (ICH6)		0x266a	32	yes	hard	yes	yes	yes
+ * 6310ESB/6320ESB		0x269b	32	yes	hard	yes	yes	yes
+ * 82801G (ICH7)		0x27da	32	yes	hard	yes	yes	yes
+ * 82801H (ICH8)		0x283e	32	yes	hard	yes	yes	yes
+ * 82801I (ICH9)		0x2930	32	yes	hard	yes	yes	yes
+ * EP80579 (Tolapai)		0x5032	32	yes	hard	yes	yes	yes
+ * ICH10			0x3a30	32	yes	hard	yes	yes	yes
+ * ICH10			0x3a60	32	yes	hard	yes	yes	yes
+ * 5/3400 Series (PCH)		0x3b30	32	yes	hard	yes	yes	yes
+ * 6 Series (PCH)		0x1c22	32	yes	hard	yes	yes	yes
+ * Patsburg (PCH)		0x1d22	32	yes	hard	yes	yes	yes
+ * Patsburg (PCH) IDF		0x1d70	32	yes	hard	yes	yes	yes
+ * Patsburg (PCH) IDF		0x1d71	32	yes	hard	yes	yes	yes
+ * Patsburg (PCH) IDF		0x1d72	32	yes	hard	yes	yes	yes
+ * DH89xxCC (PCH)		0x2330	32	yes	hard	yes	yes	yes
+ * Panther Point (PCH)		0x1e22	32	yes	hard	yes	yes	yes
+ * Lynx Point (PCH)		0x8c22	32	yes	hard	yes	yes	yes
+ * Lynx Point-LP (PCH)		0x9c22	32	yes	hard	yes	yes	yes
+ * Avoton (SOC)			0x1f3c	32	yes	hard	yes	yes	yes
+ * Wellsburg (PCH)		0x8d22	32	yes	hard	yes	yes	yes
+ * Wellsburg (PCH) MS		0x8d7d	32	yes	hard	yes	yes	yes
+ * Wellsburg (PCH) MS		0x8d7e	32	yes	hard	yes	yes	yes
+ * Wellsburg (PCH) MS		0x8d7f	32	yes	hard	yes	yes	yes
+ * Coleto Creek (PCH)		0x23b0	32	yes	hard	yes	yes	yes
+ * Wildcat Point (PCH)		0x8ca2	32	yes	hard	yes	yes	yes
+ * Wildcat Point-LP (PCH)	0x9ca2	32	yes	hard	yes	yes	yes
+ * BayTrail (SOC)		0x0f12	32	yes	hard	yes	yes	yes
+ * Sunrise Point-H (PCH)	0xa123  32	yes	hard	yes	yes	yes
+ * Sunrise Point-LP (PCH)	0x9d23	32	yes	hard	yes	yes	yes
  *
  * Features supported by this driver:
  * Software PEC				no
@@ -68,6 +68,7 @@
  * Block process call transaction	no
  * I2C block read transaction		yes (doesn't use the block buffer)
  * Slave mode				no
+ * SMBus Host Notify			yes
  * Interrupt processing			yes
  *
  * See the file Documentation/i2c/busses/i2c-i801 for details.
@@ -82,6 +83,7 @@
 #include <linux/ioport.h>
 #include <linux/init.h>
 #include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
 #include <linux/acpi.h>
 #include <linux/io.h>
 #include <linux/dmi.h>
@@ -107,6 +109,10 @@
 #define SMBPEC(p)	(8 + (p)->smba)		/* ICH3 and later */
 #define SMBAUXSTS(p)	(12 + (p)->smba)	/* ICH4 and later */
 #define SMBAUXCTL(p)	(13 + (p)->smba)	/* ICH4 and later */
+#define SMBSLVSTS(p)	(16 + (p)->smba)	/* ICH3 and later */
+#define SMBSLVCMD(p)	(17 + (p)->smba)	/* ICH3 and later */
+#define SMBNTFDADD(p)	(20 + (p)->smba)	/* ICH3 and later */
+#define SMBNTFDDAT(p)	(22 + (p)->smba)	/* ICH3 and later */
 
 /* PCI Address Constants */
 #define SMBBAR		4
@@ -158,6 +164,12 @@
 #define SMBHSTSTS_INTR		0x02
 #define SMBHSTSTS_HOST_BUSY	0x01
 
+/* Host Notify Status registers bits */
+#define SMBSLVSTS_HST_NTFY_STS	1
+
+/* Host Notify Command registers bits */
+#define SMBSLVCMD_HST_NTFY_INTREN	0x01
+
 #define STATUS_ERROR_FLAGS	(SMBHSTSTS_FAILED | SMBHSTSTS_BUS_ERR | \
 				 SMBHSTSTS_DEV_ERR)
 
@@ -221,13 +233,18 @@ struct i801_priv {
 	const struct i801_mux_config *mux_drvdata;
 	struct platform_device *mux_pdev;
 #endif
+
+	struct work_struct host_notify;
 };
 
+#define SMBHSTNTFY_SIZE		8
+
 #define FEATURE_SMBUS_PEC	(1 << 0)
 #define FEATURE_BLOCK_BUFFER	(1 << 1)
 #define FEATURE_BLOCK_PROC	(1 << 2)
 #define FEATURE_I2C_BLOCK_READ	(1 << 3)
 #define FEATURE_IRQ		(1 << 4)
+#define FEATURE_HOST_NOTIFY	(1 << 5)
 /* Not really a feature, but it's convenient to handle it as such */
 #define FEATURE_IDF		(1 << 15)
 
@@ -237,6 +254,7 @@ static const char *i801_feature_names[] = {
 	"Block process call",
 	"I2C block read",
 	"Interrupt",
+	"SMBus Host Notify",
 };
 
 static unsigned int disable_features;
@@ -245,7 +263,8 @@ MODULE_PARM_DESC(disable_features, "Disable selected driver features:\n"
 	"\t\t  0x01  disable SMBus PEC\n"
 	"\t\t  0x02  disable the block buffer\n"
 	"\t\t  0x08  disable the I2C block read functionality\n"
-	"\t\t  0x10  don't use interrupts ");
+	"\t\t  0x10  don't use interrupts\n"
+	"\t\t  0x20  disable SMBus Host Notify ");
 
 /* Make sure the SMBus host is ready to start transmitting.
    Return 0 if it is, -EBUSY if it is not. */
@@ -480,7 +499,36 @@ static void i801_isr_byte_done(struct i801_priv *priv)
 }
 
 /*
- * There are two kinds of interrupts:
+ * The Host Notify IRQ handler needs to hand work off to a task which can
+ * sleep, because i2c_propagate_smbus_host_notify() can't be called in IRQ
+ * context.
+ */
+static void i801_host_notify(struct work_struct *work)
+{
+	struct i801_priv *priv;
+	unsigned short addr;
+	unsigned int data;
+
+	priv = container_of(work, struct i801_priv, host_notify);
+
+	addr = inb_p(SMBNTFDADD(priv)) >> 1;
+	data = inw_p(SMBNTFDDAT(priv));
+
+	/* clear Host Notify bit to allow a new interrupt */
+	outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv));
+
+	i2c_propagate_smbus_host_notify(&priv->adapter, addr, data);
+}
+
+static irqreturn_t i801_host_notify_isr(struct i801_priv *priv)
+{
+	schedule_work(&priv->host_notify);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * There are three kinds of interrupts:
  *
  * 1) i801 signals transaction completion with one of these interrupts:
  *      INTR - Success
@@ -492,6 +540,8 @@ static void i801_isr_byte_done(struct i801_priv *priv)
  *
  * 2) For byte-by-byte (I2C read/write) transactions, one BYTE_DONE interrupt
  *    occurs for each byte of a byte-by-byte to prepare the next byte.
+ *
+ * 3) Host Notify interrupts
  */
 static irqreturn_t i801_isr(int irq, void *dev_id)
 {
@@ -504,6 +554,12 @@ static irqreturn_t i801_isr(int irq, void *dev_id)
 	if (!(pcists & SMBPCISTS_INTS))
 		return IRQ_NONE;
 
+	if (priv->features & FEATURE_HOST_NOTIFY) {
+		status = inb_p(SMBSLVSTS(priv));
+		if (status & SMBSLVSTS_HST_NTFY_STS)
+			return i801_host_notify_isr(priv);
+	}
+
 	status = inb_p(SMBHSTSTS(priv));
 	if (status & SMBHSTSTS_BYTE_DONE)
 		i801_isr_byte_done(priv);
@@ -801,7 +857,21 @@ static u32 i801_func(struct i2c_adapter *adapter)
 	       I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_WRITE_I2C_BLOCK |
 	       ((priv->features & FEATURE_SMBUS_PEC) ? I2C_FUNC_SMBUS_PEC : 0) |
 	       ((priv->features & FEATURE_I2C_BLOCK_READ) ?
-		I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0);
+		I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0) |
+	       ((priv->features & FEATURE_HOST_NOTIFY) ?
+		I2C_FUNC_SMBUS_HOST_NOTIFY : 0);
+}
+
+static void i801_enable_host_notify(struct i2c_adapter *adapter)
+{
+	struct i801_priv *priv = i2c_get_adapdata(adapter);
+
+	if (!(priv->features & FEATURE_HOST_NOTIFY))
+		return;
+
+	outb_p(SMBSLVCMD_HST_NTFY_INTREN, SMBSLVCMD(priv));
+	/* clear Host Notify bit to allow a new notification */
+	outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv));
 }
 
 static const struct i2c_algorithm smbus_algorithm = {
@@ -1166,6 +1236,8 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 		priv->features |= FEATURE_BLOCK_BUFFER;
 		/* fall through */
 	case PCI_DEVICE_ID_INTEL_82801CA_3:
+		priv->features |= FEATURE_HOST_NOTIFY;
+		/* fall through */
 	case PCI_DEVICE_ID_INTEL_82801BA_2:
 	case PCI_DEVICE_ID_INTEL_82801AB_3:
 	case PCI_DEVICE_ID_INTEL_82801AA_3:
@@ -1250,6 +1322,8 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 		}
 	}
 
+	INIT_WORK(&priv->host_notify, i801_host_notify);
+
 	if (priv->features & FEATURE_IRQ) {
 		init_waitqueue_head(&priv->waitq);
 
@@ -1279,6 +1353,13 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 		return err;
 	}
 
+	/*
+	 * Enable Host Notify for chips that supports it.
+	 * It is done after i2c_add_adapter() so that we are sure the work queue
+	 * is not used if i2c_add_adapter() fails.
+	 */
+	i801_enable_host_notify(&priv->adapter);
+
 	i801_probe_optional_slaves(priv);
 	/* We ignore errors - multiplexing is optional */
 	i801_add_mux(priv);
@@ -1292,6 +1373,8 @@ static void i801_remove(struct pci_dev *dev)
 {
 	struct i801_priv *priv = pci_get_drvdata(dev);
 
+	cancel_work_sync(&priv->host_notify);
+
 	i801_del_mux(priv);
 	i2c_del_adapter(&priv->adapter);
 	pci_write_config_byte(dev, SMBHSTCFG, priv->original_hstcfg);
@@ -1315,8 +1398,11 @@ static int i801_suspend(struct pci_dev *dev, pm_message_t mesg)
 
 static int i801_resume(struct pci_dev *dev)
 {
+	struct i801_priv *priv = pci_get_drvdata(dev);
+
 	pci_set_power_state(dev, PCI_D0);
 	pci_restore_state(dev);
+	i801_enable_host_notify(&priv->adapter);
 	return 0;
 }
 #else
-- 
2.4.3

[PATCH v2 3/3] i2c: i801: add support of Host Notify

[Benjamin Tissoires]

The i801 chip can handle the Host Notify feature since ICH 3 as mentioned
in http://www.intel.com/content/dam/doc/datasheet/82801ca-io-controller-hub-3-datasheet.pdf

Enable the functionality unconditionally and propagate the alert
on each notification.

With a T440s and a Synaptics touchpad that implements Host Notify, the
payload data is always 0x0000, so I am not sure if the device actually
sends the payload or if there is a problem regarding the implementation.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
---

Changes in v2:
- removed the description of the Slave functionality support in the chip table
  (the table shows what is supported, not what the hardware is capable of)
- use i2c-smbus to forward the notification
- remove the fifo, and directly retrieve the address and payload in the worker
- do not check for Host Notification is the feature is not enabled
- use inw_p() to read the payload instead of 2 inb_p() calls
- add /* fall-through */ comment
- unconditionally enable Host Notify if the hardware supports it (can be
  disabled by the user)

 drivers/i2c/busses/i2c-i801.c | 172 +++++++++++++++++++++++++++++++-----------
 1 file changed, 129 insertions(+), 43 deletions(-)

diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 5ecbb3f..f65f955 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -20,46 +20,46 @@
 /*
  * Supports the following Intel I/O Controller Hubs (ICH):
  *
- *					I/O			Block	I2C
- *					region	SMBus	Block	proc.	block
- * Chip name			PCI ID	size	PEC	buffer	call	read
- * ---------------------------------------------------------------------------
- * 82801AA (ICH)		0x2413	16	no	no	no	no
- * 82801AB (ICH0)		0x2423	16	no	no	no	no
- * 82801BA (ICH2)		0x2443	16	no	no	no	no
- * 82801CA (ICH3)		0x2483	32	soft	no	no	no
- * 82801DB (ICH4)		0x24c3	32	hard	yes	no	no
- * 82801E (ICH5)		0x24d3	32	hard	yes	yes	yes
- * 6300ESB			0x25a4	32	hard	yes	yes	yes
- * 82801F (ICH6)		0x266a	32	hard	yes	yes	yes
- * 6310ESB/6320ESB		0x269b	32	hard	yes	yes	yes
- * 82801G (ICH7)		0x27da	32	hard	yes	yes	yes
- * 82801H (ICH8)		0x283e	32	hard	yes	yes	yes
- * 82801I (ICH9)		0x2930	32	hard	yes	yes	yes
- * EP80579 (Tolapai)		0x5032	32	hard	yes	yes	yes
- * ICH10			0x3a30	32	hard	yes	yes	yes
- * ICH10			0x3a60	32	hard	yes	yes	yes
- * 5/3400 Series (PCH)		0x3b30	32	hard	yes	yes	yes
- * 6 Series (PCH)		0x1c22	32	hard	yes	yes	yes
- * Patsburg (PCH)		0x1d22	32	hard	yes	yes	yes
- * Patsburg (PCH) IDF		0x1d70	32	hard	yes	yes	yes
- * Patsburg (PCH) IDF		0x1d71	32	hard	yes	yes	yes
- * Patsburg (PCH) IDF		0x1d72	32	hard	yes	yes	yes
- * DH89xxCC (PCH)		0x2330	32	hard	yes	yes	yes
- * Panther Point (PCH)		0x1e22	32	hard	yes	yes	yes
- * Lynx Point (PCH)		0x8c22	32	hard	yes	yes	yes
- * Lynx Point-LP (PCH)		0x9c22	32	hard	yes	yes	yes
- * Avoton (SOC)			0x1f3c	32	hard	yes	yes	yes
- * Wellsburg (PCH)		0x8d22	32	hard	yes	yes	yes
- * Wellsburg (PCH) MS		0x8d7d	32	hard	yes	yes	yes
- * Wellsburg (PCH) MS		0x8d7e	32	hard	yes	yes	yes
- * Wellsburg (PCH) MS		0x8d7f	32	hard	yes	yes	yes
- * Coleto Creek (PCH)		0x23b0	32	hard	yes	yes	yes
- * Wildcat Point (PCH)		0x8ca2	32	hard	yes	yes	yes
- * Wildcat Point-LP (PCH)	0x9ca2	32	hard	yes	yes	yes
- * BayTrail (SOC)		0x0f12	32	hard	yes	yes	yes
- * Sunrise Point-H (PCH) 	0xa123  32	hard	yes	yes	yes
- * Sunrise Point-LP (PCH)	0x9d23	32	hard	yes	yes	yes
+ *					I/O	SMBus	Block	I2C
+ *					region	Host	SMBus	Block	proc.	block
+ * Chip name			PCI ID	size	notify	PEC	buffer	call	read
+ * ----------------------------------------------------------------------------------
+ * 82801AA (ICH)		0x2413	16	no	no	no	no	no
+ * 82801AB (ICH0)		0x2423	16	no	no	no	no	no
+ * 82801BA (ICH2)		0x2443	16	no	no	no	no	no
+ * 82801CA (ICH3)		0x2483	32	yes	soft	no	no	no
+ * 82801DB (ICH4)		0x24c3	32	yes	hard	yes	no	no
+ * 82801E (ICH5)		0x24d3	32	yes	hard	yes	yes	yes
+ * 6300ESB			0x25a4	32	yes	hard	yes	yes	yes
+ * 82801F (ICH6)		0x266a	32	yes	hard	yes	yes	yes
+ * 6310ESB/6320ESB		0x269b	32	yes	hard	yes	yes	yes
+ * 82801G (ICH7)		0x27da	32	yes	hard	yes	yes	yes
+ * 82801H (ICH8)		0x283e	32	yes	hard	yes	yes	yes
+ * 82801I (ICH9)		0x2930	32	yes	hard	yes	yes	yes
+ * EP80579 (Tolapai)		0x5032	32	yes	hard	yes	yes	yes
+ * ICH10			0x3a30	32	yes	hard	yes	yes	yes
+ * ICH10			0x3a60	32	yes	hard	yes	yes	yes
+ * 5/3400 Series (PCH)		0x3b30	32	yes	hard	yes	yes	yes
+ * 6 Series (PCH)		0x1c22	32	yes	hard	yes	yes	yes
+ * Patsburg (PCH)		0x1d22	32	yes	hard	yes	yes	yes
+ * Patsburg (PCH) IDF		0x1d70	32	yes	hard	yes	yes	yes
+ * Patsburg (PCH) IDF		0x1d71	32	yes	hard	yes	yes	yes
+ * Patsburg (PCH) IDF		0x1d72	32	yes	hard	yes	yes	yes
+ * DH89xxCC (PCH)		0x2330	32	yes	hard	yes	yes	yes
+ * Panther Point (PCH)		0x1e22	32	yes	hard	yes	yes	yes
+ * Lynx Point (PCH)		0x8c22	32	yes	hard	yes	yes	yes
+ * Lynx Point-LP (PCH)		0x9c22	32	yes	hard	yes	yes	yes
+ * Avoton (SOC)			0x1f3c	32	yes	hard	yes	yes	yes
+ * Wellsburg (PCH)		0x8d22	32	yes	hard	yes	yes	yes
+ * Wellsburg (PCH) MS		0x8d7d	32	yes	hard	yes	yes	yes
+ * Wellsburg (PCH) MS		0x8d7e	32	yes	hard	yes	yes	yes
+ * Wellsburg (PCH) MS		0x8d7f	32	yes	hard	yes	yes	yes
+ * Coleto Creek (PCH)		0x23b0	32	yes	hard	yes	yes	yes
+ * Wildcat Point (PCH)		0x8ca2	32	yes	hard	yes	yes	yes
+ * Wildcat Point-LP (PCH)	0x9ca2	32	yes	hard	yes	yes	yes
+ * BayTrail (SOC)		0x0f12	32	yes	hard	yes	yes	yes
+ * Sunrise Point-H (PCH)	0xa123  32	yes	hard	yes	yes	yes
+ * Sunrise Point-LP (PCH)	0x9d23	32	yes	hard	yes	yes	yes
  *
  * Features supported by this driver:
  * Software PEC				no
@@ -68,6 +68,7 @@
  * Block process call transaction	no
  * I2C block read transaction		yes (doesn't use the block buffer)
  * Slave mode				no
+ * SMBus Host Notify			yes
  * Interrupt processing			yes
  *
  * See the file Documentation/i2c/busses/i2c-i801 for details.
@@ -82,6 +83,7 @@
 #include <linux/ioport.h>
 #include <linux/init.h>
 #include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
 #include <linux/acpi.h>
 #include <linux/io.h>
 #include <linux/dmi.h>
@@ -107,6 +109,10 @@
 #define SMBPEC(p)	(8 + (p)->smba)		/* ICH3 and later */
 #define SMBAUXSTS(p)	(12 + (p)->smba)	/* ICH4 and later */
 #define SMBAUXCTL(p)	(13 + (p)->smba)	/* ICH4 and later */
+#define SMBSLVSTS(p)	(16 + (p)->smba)	/* ICH3 and later */
+#define SMBSLVCMD(p)	(17 + (p)->smba)	/* ICH3 and later */
+#define SMBNTFDADD(p)	(20 + (p)->smba)	/* ICH3 and later */
+#define SMBNTFDDAT(p)	(22 + (p)->smba)	/* ICH3 and later */
 
 /* PCI Address Constants */
 #define SMBBAR		4
@@ -158,6 +164,12 @@
 #define SMBHSTSTS_INTR		0x02
 #define SMBHSTSTS_HOST_BUSY	0x01
 
+/* Host Notify Status registers bits */
+#define SMBSLVSTS_HST_NTFY_STS	1
+
+/* Host Notify Command registers bits */
+#define SMBSLVCMD_HST_NTFY_INTREN	0x01
+
 #define STATUS_ERROR_FLAGS	(SMBHSTSTS_FAILED | SMBHSTSTS_BUS_ERR | \
 				 SMBHSTSTS_DEV_ERR)
 
@@ -221,13 +233,18 @@ struct i801_priv {
 	const struct i801_mux_config *mux_drvdata;
 	struct platform_device *mux_pdev;
 #endif
+
+	struct work_struct host_notify;
 };
 
+#define SMBHSTNTFY_SIZE		8
+
 #define FEATURE_SMBUS_PEC	(1 << 0)
 #define FEATURE_BLOCK_BUFFER	(1 << 1)
 #define FEATURE_BLOCK_PROC	(1 << 2)
 #define FEATURE_I2C_BLOCK_READ	(1 << 3)
 #define FEATURE_IRQ		(1 << 4)
+#define FEATURE_HOST_NOTIFY	(1 << 5)
 /* Not really a feature, but it's convenient to handle it as such */
 #define FEATURE_IDF		(1 << 15)
 
@@ -237,6 +254,7 @@ static const char *i801_feature_names[] = {
 	"Block process call",
 	"I2C block read",
 	"Interrupt",
+	"SMBus Host Notify",
 };
 
 static unsigned int disable_features;
@@ -245,7 +263,8 @@ MODULE_PARM_DESC(disable_features, "Disable selected driver features:\n"
 	"\t\t  0x01  disable SMBus PEC\n"
 	"\t\t  0x02  disable the block buffer\n"
 	"\t\t  0x08  disable the I2C block read functionality\n"
-	"\t\t  0x10  don't use interrupts ");
+	"\t\t  0x10  don't use interrupts\n"
+	"\t\t  0x20  disable SMBus Host Notify ");
 
 /* Make sure the SMBus host is ready to start transmitting.
    Return 0 if it is, -EBUSY if it is not. */
@@ -480,7 +499,36 @@ static void i801_isr_byte_done(struct i801_priv *priv)
 }
 
 /*
- * There are two kinds of interrupts:
+ * The Host Notify IRQ handler needs to hand work off to a task which can
+ * sleep, because i2c_propagate_smbus_host_notify() can't be called in IRQ
+ * context.
+ */
+static void i801_host_notify(struct work_struct *work)
+{
+	struct i801_priv *priv;
+	unsigned short addr;
+	unsigned int data;
+
+	priv = container_of(work, struct i801_priv, host_notify);
+
+	addr = inb_p(SMBNTFDADD(priv)) >> 1;
+	data = inw_p(SMBNTFDDAT(priv));
+
+	/* clear Host Notify bit to allow a new interrupt */
+	outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv));
+
+	i2c_propagate_smbus_host_notify(&priv->adapter, addr, data);
+}
+
+static irqreturn_t i801_host_notify_isr(struct i801_priv *priv)
+{
+	schedule_work(&priv->host_notify);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * There are three kinds of interrupts:
  *
  * 1) i801 signals transaction completion with one of these interrupts:
  *      INTR - Success
@@ -492,6 +540,8 @@ static void i801_isr_byte_done(struct i801_priv *priv)
  *
  * 2) For byte-by-byte (I2C read/write) transactions, one BYTE_DONE interrupt
  *    occurs for each byte of a byte-by-byte to prepare the next byte.
+ *
+ * 3) Host Notify interrupts
  */
 static irqreturn_t i801_isr(int irq, void *dev_id)
 {
@@ -504,6 +554,12 @@ static irqreturn_t i801_isr(int irq, void *dev_id)
 	if (!(pcists & SMBPCISTS_INTS))
 		return IRQ_NONE;
 
+	if (priv->features & FEATURE_HOST_NOTIFY) {
+		status = inb_p(SMBSLVSTS(priv));
+		if (status & SMBSLVSTS_HST_NTFY_STS)
+			return i801_host_notify_isr(priv);
+	}
+
 	status = inb_p(SMBHSTSTS(priv));
 	if (status & SMBHSTSTS_BYTE_DONE)
 		i801_isr_byte_done(priv);
@@ -801,7 +857,21 @@ static u32 i801_func(struct i2c_adapter *adapter)
 	       I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_WRITE_I2C_BLOCK |
 	       ((priv->features & FEATURE_SMBUS_PEC) ? I2C_FUNC_SMBUS_PEC : 0) |
 	       ((priv->features & FEATURE_I2C_BLOCK_READ) ?
-		I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0);
+		I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0) |
+	       ((priv->features & FEATURE_HOST_NOTIFY) ?
+		I2C_FUNC_SMBUS_HOST_NOTIFY : 0);
+}
+
+static void i801_enable_host_notify(struct i2c_adapter *adapter)
+{
+	struct i801_priv *priv = i2c_get_adapdata(adapter);
+
+	if (!(priv->features & FEATURE_HOST_NOTIFY))
+		return;
+
+	outb_p(SMBSLVCMD_HST_NTFY_INTREN, SMBSLVCMD(priv));
+	/* clear Host Notify bit to allow a new notification */
+	outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv));
 }
 
 static const struct i2c_algorithm smbus_algorithm = {
@@ -1166,6 +1236,8 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 		priv->features |= FEATURE_BLOCK_BUFFER;
 		/* fall through */
 	case PCI_DEVICE_ID_INTEL_82801CA_3:
+		priv->features |= FEATURE_HOST_NOTIFY;
+		/* fall through */
 	case PCI_DEVICE_ID_INTEL_82801BA_2:
 	case PCI_DEVICE_ID_INTEL_82801AB_3:
 	case PCI_DEVICE_ID_INTEL_82801AA_3:
@@ -1250,6 +1322,8 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 		}
 	}
 
+	INIT_WORK(&priv->host_notify, i801_host_notify);
+
 	if (priv->features & FEATURE_IRQ) {
 		init_waitqueue_head(&priv->waitq);
 
@@ -1279,6 +1353,13 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 		return err;
 	}
 
+	/*
+	 * Enable Host Notify for chips that supports it.
+	 * It is done after i2c_add_adapter() so that we are sure the work queue
+	 * is not used if i2c_add_adapter() fails.
+	 */
+	i801_enable_host_notify(&priv->adapter);
+
 	i801_probe_optional_slaves(priv);
 	/* We ignore errors - multiplexing is optional */
 	i801_add_mux(priv);
@@ -1292,6 +1373,8 @@ static void i801_remove(struct pci_dev *dev)
 {
 	struct i801_priv *priv = pci_get_drvdata(dev);
 
+	cancel_work_sync(&priv->host_notify);
+
 	i801_del_mux(priv);
 	i2c_del_adapter(&priv->adapter);
 	pci_write_config_byte(dev, SMBHSTCFG, priv->original_hstcfg);
@@ -1315,8 +1398,11 @@ static int i801_suspend(struct pci_dev *dev, pm_message_t mesg)
 
 static int i801_resume(struct pci_dev *dev)
 {
+	struct i801_priv *priv = pci_get_drvdata(dev);
+
 	pci_set_power_state(dev, PCI_D0);
 	pci_restore_state(dev);
+	i801_enable_host_notify(&priv->adapter);
 	return 0;
 }
 #else
-- 
2.4.3

Re: [PATCH v2 3/3] i2c: i801: add support of Host Notify

[Benjamin Tissoires]

On Jul 09 2015 or thereabouts, Benjamin Tissoires wrote:
> The i801 chip can handle the Host Notify feature since ICH 3 as mentioned
> in http://www.intel.com/content/dam/doc/datasheet/82801ca-io-controller-hub-3-datasheet.pdf
> 
> Enable the functionality unconditionally and propagate the alert
> on each notification.
> 
> With a T440s and a Synaptics touchpad that implements Host Notify, the
> payload data is always 0x0000, so I am not sure if the device actually
> sends the payload or if there is a problem regarding the implementation.
> 
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> ---
> 
> Changes in v2:
> - removed the description of the Slave functionality support in the chip table
>   (the table shows what is supported, not what the hardware is capable of)
> - use i2c-smbus to forward the notification
> - remove the fifo, and directly retrieve the address and payload in the worker
> - do not check for Host Notification is the feature is not enabled
> - use inw_p() to read the payload instead of 2 inb_p() calls
> - add /* fall-through */ comment
> - unconditionally enable Host Notify if the hardware supports it (can be
>   disabled by the user)
> 
>  drivers/i2c/busses/i2c-i801.c | 172 +++++++++++++++++++++++++++++++-----------
>  1 file changed, 129 insertions(+), 43 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
> index 5ecbb3f..f65f955 100644
> --- a/drivers/i2c/busses/i2c-i801.c
> +++ b/drivers/i2c/busses/i2c-i801.c
> @@ -20,46 +20,46 @@
>  /*
>   * Supports the following Intel I/O Controller Hubs (ICH):
>   *
> - *					I/O			Block	I2C
> - *					region	SMBus	Block	proc.	block
> - * Chip name			PCI ID	size	PEC	buffer	call	read
> - * ---------------------------------------------------------------------------
> - * 82801AA (ICH)		0x2413	16	no	no	no	no
> - * 82801AB (ICH0)		0x2423	16	no	no	no	no
> - * 82801BA (ICH2)		0x2443	16	no	no	no	no
> - * 82801CA (ICH3)		0x2483	32	soft	no	no	no
> - * 82801DB (ICH4)		0x24c3	32	hard	yes	no	no
> - * 82801E (ICH5)		0x24d3	32	hard	yes	yes	yes
> - * 6300ESB			0x25a4	32	hard	yes	yes	yes
> - * 82801F (ICH6)		0x266a	32	hard	yes	yes	yes
> - * 6310ESB/6320ESB		0x269b	32	hard	yes	yes	yes
> - * 82801G (ICH7)		0x27da	32	hard	yes	yes	yes
> - * 82801H (ICH8)		0x283e	32	hard	yes	yes	yes
> - * 82801I (ICH9)		0x2930	32	hard	yes	yes	yes
> - * EP80579 (Tolapai)		0x5032	32	hard	yes	yes	yes
> - * ICH10			0x3a30	32	hard	yes	yes	yes
> - * ICH10			0x3a60	32	hard	yes	yes	yes
> - * 5/3400 Series (PCH)		0x3b30	32	hard	yes	yes	yes
> - * 6 Series (PCH)		0x1c22	32	hard	yes	yes	yes
> - * Patsburg (PCH)		0x1d22	32	hard	yes	yes	yes
> - * Patsburg (PCH) IDF		0x1d70	32	hard	yes	yes	yes
> - * Patsburg (PCH) IDF		0x1d71	32	hard	yes	yes	yes
> - * Patsburg (PCH) IDF		0x1d72	32	hard	yes	yes	yes
> - * DH89xxCC (PCH)		0x2330	32	hard	yes	yes	yes
> - * Panther Point (PCH)		0x1e22	32	hard	yes	yes	yes
> - * Lynx Point (PCH)		0x8c22	32	hard	yes	yes	yes
> - * Lynx Point-LP (PCH)		0x9c22	32	hard	yes	yes	yes
> - * Avoton (SOC)			0x1f3c	32	hard	yes	yes	yes
> - * Wellsburg (PCH)		0x8d22	32	hard	yes	yes	yes
> - * Wellsburg (PCH) MS		0x8d7d	32	hard	yes	yes	yes
> - * Wellsburg (PCH) MS		0x8d7e	32	hard	yes	yes	yes
> - * Wellsburg (PCH) MS		0x8d7f	32	hard	yes	yes	yes
> - * Coleto Creek (PCH)		0x23b0	32	hard	yes	yes	yes
> - * Wildcat Point (PCH)		0x8ca2	32	hard	yes	yes	yes
> - * Wildcat Point-LP (PCH)	0x9ca2	32	hard	yes	yes	yes
> - * BayTrail (SOC)		0x0f12	32	hard	yes	yes	yes
> - * Sunrise Point-H (PCH) 	0xa123  32	hard	yes	yes	yes
> - * Sunrise Point-LP (PCH)	0x9d23	32	hard	yes	yes	yes
> + *					I/O	SMBus	Block	I2C
> + *					region	Host	SMBus	Block	proc.	block
> + * Chip name			PCI ID	size	notify	PEC	buffer	call	read
> + * ----------------------------------------------------------------------------------
> + * 82801AA (ICH)		0x2413	16	no	no	no	no	no
> + * 82801AB (ICH0)		0x2423	16	no	no	no	no	no
> + * 82801BA (ICH2)		0x2443	16	no	no	no	no	no
> + * 82801CA (ICH3)		0x2483	32	yes	soft	no	no	no
> + * 82801DB (ICH4)		0x24c3	32	yes	hard	yes	no	no
> + * 82801E (ICH5)		0x24d3	32	yes	hard	yes	yes	yes
> + * 6300ESB			0x25a4	32	yes	hard	yes	yes	yes
> + * 82801F (ICH6)		0x266a	32	yes	hard	yes	yes	yes
> + * 6310ESB/6320ESB		0x269b	32	yes	hard	yes	yes	yes
> + * 82801G (ICH7)		0x27da	32	yes	hard	yes	yes	yes
> + * 82801H (ICH8)		0x283e	32	yes	hard	yes	yes	yes
> + * 82801I (ICH9)		0x2930	32	yes	hard	yes	yes	yes
> + * EP80579 (Tolapai)		0x5032	32	yes	hard	yes	yes	yes
> + * ICH10			0x3a30	32	yes	hard	yes	yes	yes
> + * ICH10			0x3a60	32	yes	hard	yes	yes	yes
> + * 5/3400 Series (PCH)		0x3b30	32	yes	hard	yes	yes	yes
> + * 6 Series (PCH)		0x1c22	32	yes	hard	yes	yes	yes
> + * Patsburg (PCH)		0x1d22	32	yes	hard	yes	yes	yes
> + * Patsburg (PCH) IDF		0x1d70	32	yes	hard	yes	yes	yes
> + * Patsburg (PCH) IDF		0x1d71	32	yes	hard	yes	yes	yes
> + * Patsburg (PCH) IDF		0x1d72	32	yes	hard	yes	yes	yes
> + * DH89xxCC (PCH)		0x2330	32	yes	hard	yes	yes	yes
> + * Panther Point (PCH)		0x1e22	32	yes	hard	yes	yes	yes
> + * Lynx Point (PCH)		0x8c22	32	yes	hard	yes	yes	yes
> + * Lynx Point-LP (PCH)		0x9c22	32	yes	hard	yes	yes	yes
> + * Avoton (SOC)			0x1f3c	32	yes	hard	yes	yes	yes
> + * Wellsburg (PCH)		0x8d22	32	yes	hard	yes	yes	yes
> + * Wellsburg (PCH) MS		0x8d7d	32	yes	hard	yes	yes	yes
> + * Wellsburg (PCH) MS		0x8d7e	32	yes	hard	yes	yes	yes
> + * Wellsburg (PCH) MS		0x8d7f	32	yes	hard	yes	yes	yes
> + * Coleto Creek (PCH)		0x23b0	32	yes	hard	yes	yes	yes
> + * Wildcat Point (PCH)		0x8ca2	32	yes	hard	yes	yes	yes
> + * Wildcat Point-LP (PCH)	0x9ca2	32	yes	hard	yes	yes	yes
> + * BayTrail (SOC)		0x0f12	32	yes	hard	yes	yes	yes
> + * Sunrise Point-H (PCH)	0xa123  32	yes	hard	yes	yes	yes
> + * Sunrise Point-LP (PCH)	0x9d23	32	yes	hard	yes	yes	yes
>   *
>   * Features supported by this driver:
>   * Software PEC				no
> @@ -68,6 +68,7 @@
>   * Block process call transaction	no
>   * I2C block read transaction		yes (doesn't use the block buffer)
>   * Slave mode				no
> + * SMBus Host Notify			yes
>   * Interrupt processing			yes
>   *
>   * See the file Documentation/i2c/busses/i2c-i801 for details.
> @@ -82,6 +83,7 @@
>  #include <linux/ioport.h>
>  #include <linux/init.h>
>  #include <linux/i2c.h>
> +#include <linux/i2c-smbus.h>
>  #include <linux/acpi.h>
>  #include <linux/io.h>
>  #include <linux/dmi.h>
> @@ -107,6 +109,10 @@
>  #define SMBPEC(p)	(8 + (p)->smba)		/* ICH3 and later */
>  #define SMBAUXSTS(p)	(12 + (p)->smba)	/* ICH4 and later */
>  #define SMBAUXCTL(p)	(13 + (p)->smba)	/* ICH4 and later */
> +#define SMBSLVSTS(p)	(16 + (p)->smba)	/* ICH3 and later */
> +#define SMBSLVCMD(p)	(17 + (p)->smba)	/* ICH3 and later */
> +#define SMBNTFDADD(p)	(20 + (p)->smba)	/* ICH3 and later */
> +#define SMBNTFDDAT(p)	(22 + (p)->smba)	/* ICH3 and later */
>  
>  /* PCI Address Constants */
>  #define SMBBAR		4
> @@ -158,6 +164,12 @@
>  #define SMBHSTSTS_INTR		0x02
>  #define SMBHSTSTS_HOST_BUSY	0x01
>  
> +/* Host Notify Status registers bits */
> +#define SMBSLVSTS_HST_NTFY_STS	1
> +
> +/* Host Notify Command registers bits */
> +#define SMBSLVCMD_HST_NTFY_INTREN	0x01
> +
>  #define STATUS_ERROR_FLAGS	(SMBHSTSTS_FAILED | SMBHSTSTS_BUS_ERR | \
>  				 SMBHSTSTS_DEV_ERR)
>  
> @@ -221,13 +233,18 @@ struct i801_priv {
>  	const struct i801_mux_config *mux_drvdata;
>  	struct platform_device *mux_pdev;
>  #endif
> +
> +	struct work_struct host_notify;
>  };
>  
> +#define SMBHSTNTFY_SIZE		8
> +
>  #define FEATURE_SMBUS_PEC	(1 << 0)
>  #define FEATURE_BLOCK_BUFFER	(1 << 1)
>  #define FEATURE_BLOCK_PROC	(1 << 2)
>  #define FEATURE_I2C_BLOCK_READ	(1 << 3)
>  #define FEATURE_IRQ		(1 << 4)
> +#define FEATURE_HOST_NOTIFY	(1 << 5)
>  /* Not really a feature, but it's convenient to handle it as such */
>  #define FEATURE_IDF		(1 << 15)
>  
> @@ -237,6 +254,7 @@ static const char *i801_feature_names[] = {
>  	"Block process call",
>  	"I2C block read",
>  	"Interrupt",
> +	"SMBus Host Notify",
>  };
>  
>  static unsigned int disable_features;
> @@ -245,7 +263,8 @@ MODULE_PARM_DESC(disable_features, "Disable selected driver features:\n"
>  	"\t\t  0x01  disable SMBus PEC\n"
>  	"\t\t  0x02  disable the block buffer\n"
>  	"\t\t  0x08  disable the I2C block read functionality\n"
> -	"\t\t  0x10  don't use interrupts ");
> +	"\t\t  0x10  don't use interrupts\n"
> +	"\t\t  0x20  disable SMBus Host Notify ");
>  
>  /* Make sure the SMBus host is ready to start transmitting.
>     Return 0 if it is, -EBUSY if it is not. */
> @@ -480,7 +499,36 @@ static void i801_isr_byte_done(struct i801_priv *priv)
>  }
>  
>  /*
> - * There are two kinds of interrupts:
> + * The Host Notify IRQ handler needs to hand work off to a task which can
> + * sleep, because i2c_propagate_smbus_host_notify() can't be called in IRQ
> + * context.
> + */
> +static void i801_host_notify(struct work_struct *work)
> +{
> +	struct i801_priv *priv;
> +	unsigned short addr;
> +	unsigned int data;
> +
> +	priv = container_of(work, struct i801_priv, host_notify);
> +
> +	addr = inb_p(SMBNTFDADD(priv)) >> 1;
> +	data = inw_p(SMBNTFDDAT(priv));
> +
> +	/* clear Host Notify bit to allow a new interrupt */
> +	outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv));
> +
> +	i2c_propagate_smbus_host_notify(&priv->adapter, addr, data);

Unfortunately, it looks like this is prone to races.

We encountered a bug which makes the controller to time out when reading
data with this implementation. If there are too many I2C transactions in
the IRQ (i.e. something like 2, which can be considered as a big number :-P )
then the controller is messed up. I am working on a fix in i2c-smbus
which allows to call i2c_propagate_smbus_host_notify() from an
uninterruptible context (like i2c_handle_smbus_alert()). This way, the
registers access are done directly in the IRQ thread and the I2C
transactions will be done afterwards.

So please disregard this series, I will send a v4 hopefully soonish.

Cheers,
Benjamin

> +}
> +
> +static irqreturn_t i801_host_notify_isr(struct i801_priv *priv)
> +{
> +	schedule_work(&priv->host_notify);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +/*
> + * There are three kinds of interrupts:
>   *
>   * 1) i801 signals transaction completion with one of these interrupts:
>   *      INTR - Success
> @@ -492,6 +540,8 @@ static void i801_isr_byte_done(struct i801_priv *priv)
>   *
>   * 2) For byte-by-byte (I2C read/write) transactions, one BYTE_DONE interrupt
>   *    occurs for each byte of a byte-by-byte to prepare the next byte.
> + *
> + * 3) Host Notify interrupts
>   */
>  static irqreturn_t i801_isr(int irq, void *dev_id)
>  {
> @@ -504,6 +554,12 @@ static irqreturn_t i801_isr(int irq, void *dev_id)
>  	if (!(pcists & SMBPCISTS_INTS))
>  		return IRQ_NONE;
>  
> +	if (priv->features & FEATURE_HOST_NOTIFY) {
> +		status = inb_p(SMBSLVSTS(priv));
> +		if (status & SMBSLVSTS_HST_NTFY_STS)
> +			return i801_host_notify_isr(priv);
> +	}
> +
>  	status = inb_p(SMBHSTSTS(priv));
>  	if (status & SMBHSTSTS_BYTE_DONE)
>  		i801_isr_byte_done(priv);
> @@ -801,7 +857,21 @@ static u32 i801_func(struct i2c_adapter *adapter)
>  	       I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_WRITE_I2C_BLOCK |
>  	       ((priv->features & FEATURE_SMBUS_PEC) ? I2C_FUNC_SMBUS_PEC : 0) |
>  	       ((priv->features & FEATURE_I2C_BLOCK_READ) ?
> -		I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0);
> +		I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0) |
> +	       ((priv->features & FEATURE_HOST_NOTIFY) ?
> +		I2C_FUNC_SMBUS_HOST_NOTIFY : 0);
> +}
> +
> +static void i801_enable_host_notify(struct i2c_adapter *adapter)
> +{
> +	struct i801_priv *priv = i2c_get_adapdata(adapter);
> +
> +	if (!(priv->features & FEATURE_HOST_NOTIFY))
> +		return;
> +
> +	outb_p(SMBSLVCMD_HST_NTFY_INTREN, SMBSLVCMD(priv));
> +	/* clear Host Notify bit to allow a new notification */
> +	outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv));
>  }
>  
>  static const struct i2c_algorithm smbus_algorithm = {
> @@ -1166,6 +1236,8 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
>  		priv->features |= FEATURE_BLOCK_BUFFER;
>  		/* fall through */
>  	case PCI_DEVICE_ID_INTEL_82801CA_3:
> +		priv->features |= FEATURE_HOST_NOTIFY;
> +		/* fall through */
>  	case PCI_DEVICE_ID_INTEL_82801BA_2:
>  	case PCI_DEVICE_ID_INTEL_82801AB_3:
>  	case PCI_DEVICE_ID_INTEL_82801AA_3:
> @@ -1250,6 +1322,8 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
>  		}
>  	}
>  
> +	INIT_WORK(&priv->host_notify, i801_host_notify);
> +
>  	if (priv->features & FEATURE_IRQ) {
>  		init_waitqueue_head(&priv->waitq);
>  
> @@ -1279,6 +1353,13 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
>  		return err;
>  	}
>  
> +	/*
> +	 * Enable Host Notify for chips that supports it.
> +	 * It is done after i2c_add_adapter() so that we are sure the work queue
> +	 * is not used if i2c_add_adapter() fails.
> +	 */
> +	i801_enable_host_notify(&priv->adapter);
> +
>  	i801_probe_optional_slaves(priv);
>  	/* We ignore errors - multiplexing is optional */
>  	i801_add_mux(priv);
> @@ -1292,6 +1373,8 @@ static void i801_remove(struct pci_dev *dev)
>  {
>  	struct i801_priv *priv = pci_get_drvdata(dev);
>  
> +	cancel_work_sync(&priv->host_notify);
> +
>  	i801_del_mux(priv);
>  	i2c_del_adapter(&priv->adapter);
>  	pci_write_config_byte(dev, SMBHSTCFG, priv->original_hstcfg);
> @@ -1315,8 +1398,11 @@ static int i801_suspend(struct pci_dev *dev, pm_message_t mesg)
>  
>  static int i801_resume(struct pci_dev *dev)
>  {
> +	struct i801_priv *priv = pci_get_drvdata(dev);
> +
>  	pci_set_power_state(dev, PCI_D0);
>  	pci_restore_state(dev);
> +	i801_enable_host_notify(&priv->adapter);
>  	return 0;
>  }
>  #else
> -- 
> 2.4.3
> 

Re: [PATCH v2 3/3] i2c: i801: add support of Host Notify

[Benjamin Tissoires]

On Jul 09 2015 or thereabouts, Benjamin Tissoires wrote:
> The i801 chip can handle the Host Notify feature since ICH 3 as mentioned
> in http://www.intel.com/content/dam/doc/datasheet/82801ca-io-controller-hub-3-datasheet.pdf
> 
> Enable the functionality unconditionally and propagate the alert
> on each notification.
> 
> With a T440s and a Synaptics touchpad that implements Host Notify, the
> payload data is always 0x0000, so I am not sure if the device actually
> sends the payload or if there is a problem regarding the implementation.
> 
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
> ---
> 
> Changes in v2:
> - removed the description of the Slave functionality support in the chip table
>   (the table shows what is supported, not what the hardware is capable of)
> - use i2c-smbus to forward the notification
> - remove the fifo, and directly retrieve the address and payload in the worker
> - do not check for Host Notification is the feature is not enabled
> - use inw_p() to read the payload instead of 2 inb_p() calls
> - add /* fall-through */ comment
> - unconditionally enable Host Notify if the hardware supports it (can be
>   disabled by the user)
> 
>  drivers/i2c/busses/i2c-i801.c | 172 +++++++++++++++++++++++++++++++-----------
>  1 file changed, 129 insertions(+), 43 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
> index 5ecbb3f..f65f955 100644
> --- a/drivers/i2c/busses/i2c-i801.c
> +++ b/drivers/i2c/busses/i2c-i801.c
> @@ -20,46 +20,46 @@
>  /*
>   * Supports the following Intel I/O Controller Hubs (ICH):
>   *
> - *					I/O			Block	I2C
> - *					region	SMBus	Block	proc.	block
> - * Chip name			PCI ID	size	PEC	buffer	call	read
> - * ---------------------------------------------------------------------------
> - * 82801AA (ICH)		0x2413	16	no	no	no	no
> - * 82801AB (ICH0)		0x2423	16	no	no	no	no
> - * 82801BA (ICH2)		0x2443	16	no	no	no	no
> - * 82801CA (ICH3)		0x2483	32	soft	no	no	no
> - * 82801DB (ICH4)		0x24c3	32	hard	yes	no	no
> - * 82801E (ICH5)		0x24d3	32	hard	yes	yes	yes
> - * 6300ESB			0x25a4	32	hard	yes	yes	yes
> - * 82801F (ICH6)		0x266a	32	hard	yes	yes	yes
> - * 6310ESB/6320ESB		0x269b	32	hard	yes	yes	yes
> - * 82801G (ICH7)		0x27da	32	hard	yes	yes	yes
> - * 82801H (ICH8)		0x283e	32	hard	yes	yes	yes
> - * 82801I (ICH9)		0x2930	32	hard	yes	yes	yes
> - * EP80579 (Tolapai)		0x5032	32	hard	yes	yes	yes
> - * ICH10			0x3a30	32	hard	yes	yes	yes
> - * ICH10			0x3a60	32	hard	yes	yes	yes
> - * 5/3400 Series (PCH)		0x3b30	32	hard	yes	yes	yes
> - * 6 Series (PCH)		0x1c22	32	hard	yes	yes	yes
> - * Patsburg (PCH)		0x1d22	32	hard	yes	yes	yes
> - * Patsburg (PCH) IDF		0x1d70	32	hard	yes	yes	yes
> - * Patsburg (PCH) IDF		0x1d71	32	hard	yes	yes	yes
> - * Patsburg (PCH) IDF		0x1d72	32	hard	yes	yes	yes
> - * DH89xxCC (PCH)		0x2330	32	hard	yes	yes	yes
> - * Panther Point (PCH)		0x1e22	32	hard	yes	yes	yes
> - * Lynx Point (PCH)		0x8c22	32	hard	yes	yes	yes
> - * Lynx Point-LP (PCH)		0x9c22	32	hard	yes	yes	yes
> - * Avoton (SOC)			0x1f3c	32	hard	yes	yes	yes
> - * Wellsburg (PCH)		0x8d22	32	hard	yes	yes	yes
> - * Wellsburg (PCH) MS		0x8d7d	32	hard	yes	yes	yes
> - * Wellsburg (PCH) MS		0x8d7e	32	hard	yes	yes	yes
> - * Wellsburg (PCH) MS		0x8d7f	32	hard	yes	yes	yes
> - * Coleto Creek (PCH)		0x23b0	32	hard	yes	yes	yes
> - * Wildcat Point (PCH)		0x8ca2	32	hard	yes	yes	yes
> - * Wildcat Point-LP (PCH)	0x9ca2	32	hard	yes	yes	yes
> - * BayTrail (SOC)		0x0f12	32	hard	yes	yes	yes
> - * Sunrise Point-H (PCH) 	0xa123  32	hard	yes	yes	yes
> - * Sunrise Point-LP (PCH)	0x9d23	32	hard	yes	yes	yes
> + *					I/O	SMBus	Block	I2C
> + *					region	Host	SMBus	Block	proc.	block
> + * Chip name			PCI ID	size	notify	PEC	buffer	call	read
> + * ----------------------------------------------------------------------------------
> + * 82801AA (ICH)		0x2413	16	no	no	no	no	no
> + * 82801AB (ICH0)		0x2423	16	no	no	no	no	no
> + * 82801BA (ICH2)		0x2443	16	no	no	no	no	no
> + * 82801CA (ICH3)		0x2483	32	yes	soft	no	no	no
> + * 82801DB (ICH4)		0x24c3	32	yes	hard	yes	no	no
> + * 82801E (ICH5)		0x24d3	32	yes	hard	yes	yes	yes
> + * 6300ESB			0x25a4	32	yes	hard	yes	yes	yes
> + * 82801F (ICH6)		0x266a	32	yes	hard	yes	yes	yes
> + * 6310ESB/6320ESB		0x269b	32	yes	hard	yes	yes	yes
> + * 82801G (ICH7)		0x27da	32	yes	hard	yes	yes	yes
> + * 82801H (ICH8)		0x283e	32	yes	hard	yes	yes	yes
> + * 82801I (ICH9)		0x2930	32	yes	hard	yes	yes	yes
> + * EP80579 (Tolapai)		0x5032	32	yes	hard	yes	yes	yes
> + * ICH10			0x3a30	32	yes	hard	yes	yes	yes
> + * ICH10			0x3a60	32	yes	hard	yes	yes	yes
> + * 5/3400 Series (PCH)		0x3b30	32	yes	hard	yes	yes	yes
> + * 6 Series (PCH)		0x1c22	32	yes	hard	yes	yes	yes
> + * Patsburg (PCH)		0x1d22	32	yes	hard	yes	yes	yes
> + * Patsburg (PCH) IDF		0x1d70	32	yes	hard	yes	yes	yes
> + * Patsburg (PCH) IDF		0x1d71	32	yes	hard	yes	yes	yes
> + * Patsburg (PCH) IDF		0x1d72	32	yes	hard	yes	yes	yes
> + * DH89xxCC (PCH)		0x2330	32	yes	hard	yes	yes	yes
> + * Panther Point (PCH)		0x1e22	32	yes	hard	yes	yes	yes
> + * Lynx Point (PCH)		0x8c22	32	yes	hard	yes	yes	yes
> + * Lynx Point-LP (PCH)		0x9c22	32	yes	hard	yes	yes	yes
> + * Avoton (SOC)			0x1f3c	32	yes	hard	yes	yes	yes
> + * Wellsburg (PCH)		0x8d22	32	yes	hard	yes	yes	yes
> + * Wellsburg (PCH) MS		0x8d7d	32	yes	hard	yes	yes	yes
> + * Wellsburg (PCH) MS		0x8d7e	32	yes	hard	yes	yes	yes
> + * Wellsburg (PCH) MS		0x8d7f	32	yes	hard	yes	yes	yes
> + * Coleto Creek (PCH)		0x23b0	32	yes	hard	yes	yes	yes
> + * Wildcat Point (PCH)		0x8ca2	32	yes	hard	yes	yes	yes
> + * Wildcat Point-LP (PCH)	0x9ca2	32	yes	hard	yes	yes	yes
> + * BayTrail (SOC)		0x0f12	32	yes	hard	yes	yes	yes
> + * Sunrise Point-H (PCH)	0xa123  32	yes	hard	yes	yes	yes
> + * Sunrise Point-LP (PCH)	0x9d23	32	yes	hard	yes	yes	yes
>   *
>   * Features supported by this driver:
>   * Software PEC				no
> @@ -68,6 +68,7 @@
>   * Block process call transaction	no
>   * I2C block read transaction		yes (doesn't use the block buffer)
>   * Slave mode				no
> + * SMBus Host Notify			yes
>   * Interrupt processing			yes
>   *
>   * See the file Documentation/i2c/busses/i2c-i801 for details.
> @@ -82,6 +83,7 @@
>  #include <linux/ioport.h>
>  #include <linux/init.h>
>  #include <linux/i2c.h>
> +#include <linux/i2c-smbus.h>
>  #include <linux/acpi.h>
>  #include <linux/io.h>
>  #include <linux/dmi.h>
> @@ -107,6 +109,10 @@
>  #define SMBPEC(p)	(8 + (p)->smba)		/* ICH3 and later */
>  #define SMBAUXSTS(p)	(12 + (p)->smba)	/* ICH4 and later */
>  #define SMBAUXCTL(p)	(13 + (p)->smba)	/* ICH4 and later */
> +#define SMBSLVSTS(p)	(16 + (p)->smba)	/* ICH3 and later */
> +#define SMBSLVCMD(p)	(17 + (p)->smba)	/* ICH3 and later */
> +#define SMBNTFDADD(p)	(20 + (p)->smba)	/* ICH3 and later */
> +#define SMBNTFDDAT(p)	(22 + (p)->smba)	/* ICH3 and later */
>  
>  /* PCI Address Constants */
>  #define SMBBAR		4
> @@ -158,6 +164,12 @@
>  #define SMBHSTSTS_INTR		0x02
>  #define SMBHSTSTS_HOST_BUSY	0x01
>  
> +/* Host Notify Status registers bits */
> +#define SMBSLVSTS_HST_NTFY_STS	1
> +
> +/* Host Notify Command registers bits */
> +#define SMBSLVCMD_HST_NTFY_INTREN	0x01
> +
>  #define STATUS_ERROR_FLAGS	(SMBHSTSTS_FAILED | SMBHSTSTS_BUS_ERR | \
>  				 SMBHSTSTS_DEV_ERR)
>  
> @@ -221,13 +233,18 @@ struct i801_priv {
>  	const struct i801_mux_config *mux_drvdata;
>  	struct platform_device *mux_pdev;
>  #endif
> +
> +	struct work_struct host_notify;
>  };
>  
> +#define SMBHSTNTFY_SIZE		8
> +
>  #define FEATURE_SMBUS_PEC	(1 << 0)
>  #define FEATURE_BLOCK_BUFFER	(1 << 1)
>  #define FEATURE_BLOCK_PROC	(1 << 2)
>  #define FEATURE_I2C_BLOCK_READ	(1 << 3)
>  #define FEATURE_IRQ		(1 << 4)
> +#define FEATURE_HOST_NOTIFY	(1 << 5)
>  /* Not really a feature, but it's convenient to handle it as such */
>  #define FEATURE_IDF		(1 << 15)
>  
> @@ -237,6 +254,7 @@ static const char *i801_feature_names[] = {
>  	"Block process call",
>  	"I2C block read",
>  	"Interrupt",
> +	"SMBus Host Notify",
>  };
>  
>  static unsigned int disable_features;
> @@ -245,7 +263,8 @@ MODULE_PARM_DESC(disable_features, "Disable selected driver features:\n"
>  	"\t\t  0x01  disable SMBus PEC\n"
>  	"\t\t  0x02  disable the block buffer\n"
>  	"\t\t  0x08  disable the I2C block read functionality\n"
> -	"\t\t  0x10  don't use interrupts ");
> +	"\t\t  0x10  don't use interrupts\n"
> +	"\t\t  0x20  disable SMBus Host Notify ");
>  
>  /* Make sure the SMBus host is ready to start transmitting.
>     Return 0 if it is, -EBUSY if it is not. */
> @@ -480,7 +499,36 @@ static void i801_isr_byte_done(struct i801_priv *priv)
>  }
>  
>  /*
> - * There are two kinds of interrupts:
> + * The Host Notify IRQ handler needs to hand work off to a task which can
> + * sleep, because i2c_propagate_smbus_host_notify() can't be called in IRQ
> + * context.
> + */
> +static void i801_host_notify(struct work_struct *work)
> +{
> +	struct i801_priv *priv;
> +	unsigned short addr;
> +	unsigned int data;
> +
> +	priv = container_of(work, struct i801_priv, host_notify);
> +
> +	addr = inb_p(SMBNTFDADD(priv)) >> 1;
> +	data = inw_p(SMBNTFDDAT(priv));
> +
> +	/* clear Host Notify bit to allow a new interrupt */
> +	outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv));
> +
> +	i2c_propagate_smbus_host_notify(&priv->adapter, addr, data);

Unfortunately, it looks like this is prone to races.

We encountered a bug which makes the controller to time out when reading
data with this implementation. If there are too many I2C transactions in
the IRQ (i.e. something like 2, which can be considered as a big number :-P )
then the controller is messed up. I am working on a fix in i2c-smbus
which allows to call i2c_propagate_smbus_host_notify() from an
uninterruptible context (like i2c_handle_smbus_alert()). This way, the
registers access are done directly in the IRQ thread and the I2C
transactions will be done afterwards.

So please disregard this series, I will send a v4 hopefully soonish.

Cheers,
Benjamin

> +}
> +
> +static irqreturn_t i801_host_notify_isr(struct i801_priv *priv)
> +{
> +	schedule_work(&priv->host_notify);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +/*
> + * There are three kinds of interrupts:
>   *
>   * 1) i801 signals transaction completion with one of these interrupts:
>   *      INTR - Success
> @@ -492,6 +540,8 @@ static void i801_isr_byte_done(struct i801_priv *priv)
>   *
>   * 2) For byte-by-byte (I2C read/write) transactions, one BYTE_DONE interrupt
>   *    occurs for each byte of a byte-by-byte to prepare the next byte.
> + *
> + * 3) Host Notify interrupts
>   */
>  static irqreturn_t i801_isr(int irq, void *dev_id)
>  {
> @@ -504,6 +554,12 @@ static irqreturn_t i801_isr(int irq, void *dev_id)
>  	if (!(pcists & SMBPCISTS_INTS))
>  		return IRQ_NONE;
>  
> +	if (priv->features & FEATURE_HOST_NOTIFY) {
> +		status = inb_p(SMBSLVSTS(priv));
> +		if (status & SMBSLVSTS_HST_NTFY_STS)
> +			return i801_host_notify_isr(priv);
> +	}
> +
>  	status = inb_p(SMBHSTSTS(priv));
>  	if (status & SMBHSTSTS_BYTE_DONE)
>  		i801_isr_byte_done(priv);
> @@ -801,7 +857,21 @@ static u32 i801_func(struct i2c_adapter *adapter)
>  	       I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_WRITE_I2C_BLOCK |
>  	       ((priv->features & FEATURE_SMBUS_PEC) ? I2C_FUNC_SMBUS_PEC : 0) |
>  	       ((priv->features & FEATURE_I2C_BLOCK_READ) ?
> -		I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0);
> +		I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0) |
> +	       ((priv->features & FEATURE_HOST_NOTIFY) ?
> +		I2C_FUNC_SMBUS_HOST_NOTIFY : 0);
> +}
> +
> +static void i801_enable_host_notify(struct i2c_adapter *adapter)
> +{
> +	struct i801_priv *priv = i2c_get_adapdata(adapter);
> +
> +	if (!(priv->features & FEATURE_HOST_NOTIFY))
> +		return;
> +
> +	outb_p(SMBSLVCMD_HST_NTFY_INTREN, SMBSLVCMD(priv));
> +	/* clear Host Notify bit to allow a new notification */
> +	outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv));
>  }
>  
>  static const struct i2c_algorithm smbus_algorithm = {
> @@ -1166,6 +1236,8 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
>  		priv->features |= FEATURE_BLOCK_BUFFER;
>  		/* fall through */
>  	case PCI_DEVICE_ID_INTEL_82801CA_3:
> +		priv->features |= FEATURE_HOST_NOTIFY;
> +		/* fall through */
>  	case PCI_DEVICE_ID_INTEL_82801BA_2:
>  	case PCI_DEVICE_ID_INTEL_82801AB_3:
>  	case PCI_DEVICE_ID_INTEL_82801AA_3:
> @@ -1250,6 +1322,8 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
>  		}
>  	}
>  
> +	INIT_WORK(&priv->host_notify, i801_host_notify);
> +
>  	if (priv->features & FEATURE_IRQ) {
>  		init_waitqueue_head(&priv->waitq);
>  
> @@ -1279,6 +1353,13 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
>  		return err;
>  	}
>  
> +	/*
> +	 * Enable Host Notify for chips that supports it.
> +	 * It is done after i2c_add_adapter() so that we are sure the work queue
> +	 * is not used if i2c_add_adapter() fails.
> +	 */
> +	i801_enable_host_notify(&priv->adapter);
> +
>  	i801_probe_optional_slaves(priv);
>  	/* We ignore errors - multiplexing is optional */
>  	i801_add_mux(priv);
> @@ -1292,6 +1373,8 @@ static void i801_remove(struct pci_dev *dev)
>  {
>  	struct i801_priv *priv = pci_get_drvdata(dev);
>  
> +	cancel_work_sync(&priv->host_notify);
> +
>  	i801_del_mux(priv);
>  	i2c_del_adapter(&priv->adapter);
>  	pci_write_config_byte(dev, SMBHSTCFG, priv->original_hstcfg);
> @@ -1315,8 +1398,11 @@ static int i801_suspend(struct pci_dev *dev, pm_message_t mesg)
>  
>  static int i801_resume(struct pci_dev *dev)
>  {
> +	struct i801_priv *priv = pci_get_drvdata(dev);
> +
>  	pci_set_power_state(dev, PCI_D0);
>  	pci_restore_state(dev);
> +	i801_enable_host_notify(&priv->adapter);
>  	return 0;
>  }
>  #else
> -- 
> 2.4.3
> 

Re: [PATCH v2 3/3] i2c: i801: add support of Host Notify

[Jean Delvare]

Hi Benjamin,

On Tue, 21 Jul 2015 17:24:55 -0400, Benjamin Tissoires wrote:
> So please disregard this series, I will send a v4 hopefully soonish.

>From v2 directly to v4? Did I miss something?

-- 
Jean Delvare
SUSE L3 Support

Re: [PATCH v2 3/3] i2c: i801: add support of Host Notify

[Jean Delvare]

Hi Benjamin,

On Tue, 21 Jul 2015 17:24:55 -0400, Benjamin Tissoires wrote:
> So please disregard this series, I will send a v4 hopefully soonish.

>From v2 directly to v4? Did I miss something?

-- 
Jean Delvare
SUSE L3 Support

Re: [PATCH v2 3/3] i2c: i801: add support of Host Notify

[Benjamin Tissoires]

On Sat, Jul 25, 2015 at 12:11 PM, Jean Delvare <jdelvare-l3A5Bk7waGM@public.gmane.org> wrote:
> Hi Benjamin,
>
> On Tue, 21 Jul 2015 17:24:55 -0400, Benjamin Tissoires wrote:
>> So please disregard this series, I will send a v4 hopefully soonish.
>
> From v2 directly to v4? Did I miss something?

I had to send a v3 to amend 1/3. Given that it was a small fix, I only
resent 1/3 and not the whole series.

To stay consistent, I jumped to v4 for the new version of the series :)

Cheers,
Benjamin

Re: [PATCH v2 3/3] i2c: i801: add support of Host Notify

[Benjamin Tissoires]

On Sat, Jul 25, 2015 at 12:11 PM, Jean Delvare <jdelvare@suse.de> wrote:
> Hi Benjamin,
>
> On Tue, 21 Jul 2015 17:24:55 -0400, Benjamin Tissoires wrote:
>> So please disregard this series, I will send a v4 hopefully soonish.
>
> From v2 directly to v4? Did I miss something?

I had to send a v3 to amend 1/3. Given that it was a small fix, I only
resent 1/3 and not the whole series.

To stay consistent, I jumped to v4 for the new version of the series :)

Cheers,
Benjamin

Re: [PATCH v2 3/3] i2c: i801: add support of Host Notify

[Jean Delvare]

On Sat, 25 Jul 2015 12:22:02 -0400, Benjamin Tissoires wrote:
> On Sat, Jul 25, 2015 at 12:11 PM, Jean Delvare <jdelvare-l3A5Bk7waGM@public.gmane.org> wrote:
> > Hi Benjamin,
> >
> > On Tue, 21 Jul 2015 17:24:55 -0400, Benjamin Tissoires wrote:
> >> So please disregard this series, I will send a v4 hopefully soonish.
> >
> > From v2 directly to v4? Did I miss something?
> 
> I had to send a v3 to amend 1/3. Given that it was a small fix, I only
> resent 1/3 and not the whole series.

Never received that one, thus my confusion.

> To stay consistent, I jumped to v4 for the new version of the series :)

OK, no problem.

-- 
Jean Delvare
SUSE L3 Support

Re: [PATCH v2 3/3] i2c: i801: add support of Host Notify

[Jean Delvare]

On Sat, 25 Jul 2015 12:22:02 -0400, Benjamin Tissoires wrote:
> On Sat, Jul 25, 2015 at 12:11 PM, Jean Delvare <jdelvare@suse.de> wrote:
> > Hi Benjamin,
> >
> > On Tue, 21 Jul 2015 17:24:55 -0400, Benjamin Tissoires wrote:
> >> So please disregard this series, I will send a v4 hopefully soonish.
> >
> > From v2 directly to v4? Did I miss something?
> 
> I had to send a v3 to amend 1/3. Given that it was a small fix, I only
> resent 1/3 and not the whole series.

Never received that one, thus my confusion.

> To stay consistent, I jumped to v4 for the new version of the series :)

OK, no problem.

-- 
Jean Delvare
SUSE L3 Support

Re: [PATCH v2 3/3] i2c: i801: add support of Host Notify

[Benjamin Tissoires]

On Sat, Jul 25, 2015 at 5:38 PM, Jean Delvare <jdelvare-l3A5Bk7waGM@public.gmane.org> wrote:
> On Sat, 25 Jul 2015 12:22:02 -0400, Benjamin Tissoires wrote:
>> On Sat, Jul 25, 2015 at 12:11 PM, Jean Delvare <jdelvare-l3A5Bk7waGM@public.gmane.org> wrote:
>> > Hi Benjamin,
>> >
>> > On Tue, 21 Jul 2015 17:24:55 -0400, Benjamin Tissoires wrote:
>> >> So please disregard this series, I will send a v4 hopefully soonish.
>> >
>> > From v2 directly to v4? Did I miss something?
>>
>> I had to send a v3 to amend 1/3. Given that it was a small fix, I only
>> resent 1/3 and not the whole series.
>
> Never received that one, thus my confusion.

After a second thought, I wonder if you received also the v4. It looks
fine on my side (you are CC-ed to it), but given that you missed the
v3, I'd rather be sure you have the v4 on your radar before we forget
about it.
Can you check that you have actually received
http://www.spinics.net/lists/linux-i2c/msg20616.html and the 3 after?

(the v3 was http://www.spinics.net/lists/linux-i2c/msg20418.html)

Cheers,
Benjamin

Re: [PATCH v2 3/3] i2c: i801: add support of Host Notify

[Benjamin Tissoires]

On Sat, Jul 25, 2015 at 5:38 PM, Jean Delvare <jdelvare@suse.de> wrote:
> On Sat, 25 Jul 2015 12:22:02 -0400, Benjamin Tissoires wrote:
>> On Sat, Jul 25, 2015 at 12:11 PM, Jean Delvare <jdelvare@suse.de> wrote:
>> > Hi Benjamin,
>> >
>> > On Tue, 21 Jul 2015 17:24:55 -0400, Benjamin Tissoires wrote:
>> >> So please disregard this series, I will send a v4 hopefully soonish.
>> >
>> > From v2 directly to v4? Did I miss something?
>>
>> I had to send a v3 to amend 1/3. Given that it was a small fix, I only
>> resent 1/3 and not the whole series.
>
> Never received that one, thus my confusion.

After a second thought, I wonder if you received also the v4. It looks
fine on my side (you are CC-ed to it), but given that you missed the
v3, I'd rather be sure you have the v4 on your radar before we forget
about it.
Can you check that you have actually received
http://www.spinics.net/lists/linux-i2c/msg20616.html and the 3 after?

(the v3 was http://www.spinics.net/lists/linux-i2c/msg20418.html)

Cheers,
Benjamin

Re: [PATCH v2 3/3] i2c: i801: add support of Host Notify

[Jean Delvare]

On Wed, 29 Jul 2015 10:58:13 -0400, Benjamin Tissoires wrote:
> On Sat, Jul 25, 2015 at 5:38 PM, Jean Delvare <jdelvare-l3A5Bk7waGM@public.gmane.org> wrote:
> > On Sat, 25 Jul 2015 12:22:02 -0400, Benjamin Tissoires wrote:
> >> On Sat, Jul 25, 2015 at 12:11 PM, Jean Delvare <jdelvare-l3A5Bk7waGM@public.gmane.org> wrote:
> >> > Hi Benjamin,
> >> >
> >> > On Tue, 21 Jul 2015 17:24:55 -0400, Benjamin Tissoires wrote:
> >> >> So please disregard this series, I will send a v4 hopefully soonish.
> >> >
> >> > From v2 directly to v4? Did I miss something?
> >>
> >> I had to send a v3 to amend 1/3. Given that it was a small fix, I only
> >> resent 1/3 and not the whole series.
> >
> > Never received that one, thus my confusion.
> 
> After a second thought, I wonder if you received also the v4. It looks
> fine on my side (you are CC-ed to it), but given that you missed the
> v3, I'd rather be sure you have the v4 on your radar before we forget
> about it.
> Can you check that you have actually received
> http://www.spinics.net/lists/linux-i2c/msg20616.html and the 3 after?
> 
> (the v3 was http://www.spinics.net/lists/linux-i2c/msg20418.html)

I did receive v4, and also v3. The problem is on my side, the email
address change at suse confused my mail filters and the mails were not
where I was looking for them.

-- 
Jean Delvare
SUSE L3 Support

Re: [PATCH v2 3/3] i2c: i801: add support of Host Notify

[Jean Delvare]

On Wed, 29 Jul 2015 10:58:13 -0400, Benjamin Tissoires wrote:
> On Sat, Jul 25, 2015 at 5:38 PM, Jean Delvare <jdelvare@suse.de> wrote:
> > On Sat, 25 Jul 2015 12:22:02 -0400, Benjamin Tissoires wrote:
> >> On Sat, Jul 25, 2015 at 12:11 PM, Jean Delvare <jdelvare@suse.de> wrote:
> >> > Hi Benjamin,
> >> >
> >> > On Tue, 21 Jul 2015 17:24:55 -0400, Benjamin Tissoires wrote:
> >> >> So please disregard this series, I will send a v4 hopefully soonish.
> >> >
> >> > From v2 directly to v4? Did I miss something?
> >>
> >> I had to send a v3 to amend 1/3. Given that it was a small fix, I only
> >> resent 1/3 and not the whole series.
> >
> > Never received that one, thus my confusion.
> 
> After a second thought, I wonder if you received also the v4. It looks
> fine on my side (you are CC-ed to it), but given that you missed the
> v3, I'd rather be sure you have the v4 on your radar before we forget
> about it.
> Can you check that you have actually received
> http://www.spinics.net/lists/linux-i2c/msg20616.html and the 3 after?
> 
> (the v3 was http://www.spinics.net/lists/linux-i2c/msg20418.html)

I did receive v4, and also v3. The problem is on my side, the email
address change at suse confused my mail filters and the mails were not
where I was looking for them.

-- 
Jean Delvare
SUSE L3 Support

[PATCH v2 2/3] i2c-smbus: add SMBus Host Notify support

[Benjamin Tissoires]

SMBus Host Notify allows a slave device to act as a master on a bus to
notify the host of an interrupt. On Intel chipsets, the functionality
is directly implemented in the firmware. We just need to export a
function to call .alert() on the proper device driver.

Compared to i2c_handle_smbus_alert(), it is much more convenient to
require to be able to sleep in i2c_propagate_smbus_host_notify().
device_(un)lock() in smbus_do_alert() needs to be able to sleep,
but because the address and payload are given directly by the caller
scheduling a new task would require a fifo or a lock on the current
I2C address and payload.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
---

Changes in v2:
- do the actual processing of finding the device in i2c-smbus.c
- remove the i2c-core implementations
- remove the manual toggle of SMBus Host Notify

 Documentation/i2c/smbus-protocol |  3 +++
 drivers/i2c/i2c-smbus.c          | 36 +++++++++++++++++++++++++++++++-----
 include/linux/i2c-smbus.h        |  8 ++++++++
 include/linux/i2c.h              |  3 +++
 include/uapi/linux/i2c.h         |  1 +
 5 files changed, 46 insertions(+), 5 deletions(-)

diff --git a/Documentation/i2c/smbus-protocol b/Documentation/i2c/smbus-protocol
index 6012b12..4e07848 100644
--- a/Documentation/i2c/smbus-protocol
+++ b/Documentation/i2c/smbus-protocol
@@ -199,6 +199,9 @@ alerting device's address.
 
 [S] [HostAddr] [Wr] A [DevAddr] A [DataLow] A [DataHigh] A [P]
 
+I2C drivers for devices which can trigger SMBus Host Notify should implement
+the optional alert() callback.
+
 
 Packet Error Checking (PEC)
 ===========================
diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c
index abad351..c348c1a 100644
--- a/drivers/i2c/i2c-smbus.c
+++ b/drivers/i2c/i2c-smbus.c
@@ -33,7 +33,8 @@ struct i2c_smbus_alert {
 
 struct alert_data {
 	unsigned short		addr;
-	u8			flag:1;
+	enum i2c_alert_protocol	type;
+	unsigned int		data;
 };
 
 /* If this is the alerting device, notify its driver */
@@ -56,8 +57,7 @@ static int smbus_do_alert(struct device *dev, void *addrp)
 	if (client->dev.driver) {
 		driver = to_i2c_driver(client->dev.driver);
 		if (driver->alert)
-			driver->alert(client, I2C_PROTOCOL_SMBUS_ALERT,
-				      data->flag);
+			driver->alert(client, data->type, data->data);
 		else
 			dev_warn(&client->dev, "no driver alert()!\n");
 	} else
@@ -97,8 +97,9 @@ static void smbus_alert(struct work_struct *work)
 		if (status < 0)
 			break;
 
-		data.flag = status & 1;
+		data.data = status & 1;
 		data.addr = status >> 1;
+		data.type = I2C_PROTOCOL_SMBUS_ALERT;
 
 		if (data.addr == prev_addr) {
 			dev_warn(&ara->dev, "Duplicate SMBALERT# from dev "
@@ -106,7 +107,7 @@ static void smbus_alert(struct work_struct *work)
 			break;
 		}
 		dev_dbg(&ara->dev, "SMBALERT# from dev 0x%02x, flag %d\n",
-			data.addr, data.flag);
+			data.addr, data.data);
 
 		/* Notify driver for the device which issued the alert */
 		device_for_each_child(&ara->adapter->dev, &data,
@@ -240,6 +241,31 @@ int i2c_handle_smbus_alert(struct i2c_client *ara)
 }
 EXPORT_SYMBOL_GPL(i2c_handle_smbus_alert);
 
+/**
+ * i2c_propagate_smbus_host_notify - Forward a Host Notify event to the correct
+ * I2C client.
+ * @adapter: the adapter that triggered the Host Notify event
+ * @data: the Host Notify data which contains the payload and address of the
+ * client
+ * Context: Must be able to sleep
+ *
+ * Helper function to be called from an I2C bus driver's interrupt
+ * handler that can sleep. It will call the Host Notify callback of the I2C
+ * device driver if it is found on the adapter.
+ */
+void i2c_propagate_smbus_host_notify(struct i2c_adapter *adapter,
+				     unsigned short addr, unsigned int data)
+{
+	struct alert_data alert = {
+		.type = I2C_PROTOCOL_SMBUS_HOST_NOTIFY,
+		.addr = addr,
+		.data = data,
+	};
+
+	device_for_each_child(&adapter->dev, &alert, smbus_do_alert);
+}
+EXPORT_SYMBOL_GPL(i2c_propagate_smbus_host_notify);
+
 module_i2c_driver(smbalert_driver);
 
 MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
diff --git a/include/linux/i2c-smbus.h b/include/linux/i2c-smbus.h
index 8f1b086..285efe05 100644
--- a/include/linux/i2c-smbus.h
+++ b/include/linux/i2c-smbus.h
@@ -48,4 +48,12 @@ struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
 					 struct i2c_smbus_alert_setup *setup);
 int i2c_handle_smbus_alert(struct i2c_client *ara);
 
+#if defined(CONFIG_I2C_SMBUS) || defined(CONFIG_I2C_SMBUS_MODULE)
+void i2c_propagate_smbus_host_notify(struct i2c_adapter *adapter,
+				     unsigned short addr, unsigned int data);
+#else
+static inline void i2c_propagate_smbus_host_notify(struct i2c_adapter *adapter,
+				     unsigned short addr, unsigned int data) {}
+#endif /* I2C_SMBUS */
+
 #endif /* _LINUX_I2C_SMBUS_H */
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 6764734..81344d3 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -125,6 +125,7 @@ extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
 
 enum i2c_alert_protocol {
 	I2C_PROTOCOL_SMBUS_ALERT,
+	I2C_PROTOCOL_SMBUS_HOST_NOTIFY,
 };
 
 /**
@@ -181,6 +182,8 @@ struct i2c_driver {
 	 * The format and meaning of the data value depends on the protocol.
 	 * For the SMBus alert protocol, there is a single bit of data passed
 	 * as the alert response's low bit ("event flag").
+	 * For the SMBus Host Notify protocol, the data corresponds to the
+	 * 16-bit payload data reported by the slave device acting as master.
 	 */
 	void (*alert)(struct i2c_client *, enum i2c_alert_protocol protocol,
 		      unsigned int data);
diff --git a/include/uapi/linux/i2c.h b/include/uapi/linux/i2c.h
index b0a7dd6..83ec8ae 100644
--- a/include/uapi/linux/i2c.h
+++ b/include/uapi/linux/i2c.h
@@ -101,6 +101,7 @@ struct i2c_msg {
 #define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000
 #define I2C_FUNC_SMBUS_READ_I2C_BLOCK	0x04000000 /* I2C-like block xfer  */
 #define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK	0x08000000 /* w/ 1-byte reg. addr. */
+#define I2C_FUNC_SMBUS_HOST_NOTIFY	0x10000000
 
 #define I2C_FUNC_SMBUS_BYTE		(I2C_FUNC_SMBUS_READ_BYTE | \
 					 I2C_FUNC_SMBUS_WRITE_BYTE)
-- 
2.4.3