* [PATCH v4 0/3] I2C/SMBus: add support for Host Notify (in i2c_i801)
@ 2015-07-23 18:55 ` Benjamin Tissoires
0 siblings, 0 replies; 8+ messages in thread
From: Benjamin Tissoires @ 2015-07-23 18:55 UTC (permalink / raw
To: Wolfram Sang, Jean Delvare, Dmitry Torokhov
Cc: benjamin.tissoires, linux-i2c, linux-kernel, Benjamin Tissoires
Hi,
this is the v4 of this patch series which fixes the race we discovered this
week when accessing the registers in i2c_i801.
Compared to v3, i2c_handle_smbus_host_notify can now be called in a non sleeping
thread because a worker will be spawn later on.
That also means that we need to allocate the worker and some other structures,
so I introduced i2c_setup_smbus_host_notify().
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/hwmon/lm90.c | 3 +-
drivers/i2c/busses/i2c-i801.c | 164 +++++++++++++++++++++++++++++----------
drivers/i2c/i2c-smbus.c | 113 +++++++++++++++++++++++++--
include/linux/i2c-smbus.h | 43 ++++++++++
include/linux/i2c.h | 10 ++-
include/uapi/linux/i2c.h | 1 +
8 files changed, 292 insertions(+), 51 deletions(-)
--
2.4.3
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v4 0/3] I2C/SMBus: add support for Host Notify (in i2c_i801)
@ 2015-07-23 18:55 ` Benjamin Tissoires
0 siblings, 0 replies; 8+ messages in thread
From: Benjamin Tissoires @ 2015-07-23 18:55 UTC (permalink / raw
To: Wolfram Sang, Jean Delvare, Dmitry Torokhov
Cc: benjamin.tissoires-Re5JQEeQqe8AvxtiuMwx3w,
linux-i2c-u79uwXL29TY76Z2rM5mHXA,
linux-kernel-u79uwXL29TY76Z2rM5mHXA, Benjamin Tissoires
Hi,
this is the v4 of this patch series which fixes the race we discovered this
week when accessing the registers in i2c_i801.
Compared to v3, i2c_handle_smbus_host_notify can now be called in a non sleeping
thread because a worker will be spawn later on.
That also means that we need to allocate the worker and some other structures,
so I introduced i2c_setup_smbus_host_notify().
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/hwmon/lm90.c | 3 +-
drivers/i2c/busses/i2c-i801.c | 164 +++++++++++++++++++++++++++++----------
drivers/i2c/i2c-smbus.c | 113 +++++++++++++++++++++++++--
include/linux/i2c-smbus.h | 43 ++++++++++
include/linux/i2c.h | 10 ++-
include/uapi/linux/i2c.h | 1 +
8 files changed, 292 insertions(+), 51 deletions(-)
--
2.4.3
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v4 1/3] i2c: add a protocol parameter to the alert callback
@ 2015-07-23 18:55 ` Benjamin Tissoires
0 siblings, 0 replies; 8+ messages in thread
From: Benjamin Tissoires @ 2015-07-23 18:55 UTC (permalink / raw
To: Wolfram Sang, Jean Delvare, Dmitry Torokhov
Cc: benjamin.tissoires, linux-i2c, linux-kernel, 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
changes in v3:
- added also lm90.c to support the new API
no changes in v4
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
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v4 1/3] i2c: add a protocol parameter to the alert callback
@ 2015-07-23 18:55 ` Benjamin Tissoires
0 siblings, 0 replies; 8+ messages in thread
From: Benjamin Tissoires @ 2015-07-23 18:55 UTC (permalink / raw
To: Wolfram Sang, Jean Delvare, Dmitry Torokhov
Cc: benjamin.tissoires-Re5JQEeQqe8AvxtiuMwx3w,
linux-i2c-u79uwXL29TY76Z2rM5mHXA,
linux-kernel-u79uwXL29TY76Z2rM5mHXA, 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
changes in v3:
- added also lm90.c to support the new API
no changes in v4
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
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v4 2/3] i2c-smbus: add SMBus Host Notify support
2015-07-23 18:55 ` Benjamin Tissoires
(?)
(?)
@ 2015-07-23 18:55 ` Benjamin Tissoires
-1 siblings, 0 replies; 8+ messages in thread
From: Benjamin Tissoires @ 2015-07-23 18:55 UTC (permalink / raw
To: Wolfram Sang, Jean Delvare, Dmitry Torokhov
Cc: benjamin.tissoires, linux-i2c, linux-kernel, 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.
i2c_handle_smbus_host_notify() behaves like i2c_handle_smbus_alert().
When called, it schedules a task that will be able to sleep to go through
the list of devices attached to the adapter.
The current implementation allows one Host Notification to be scheduled
while an other is running.
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
no changes in v3
changes in v4:
- schedule the worker in i2c_handle_smbus_host_notify() -> it can now be called
in an interrupt context.
- introduce i2c_setup_smbus_host_notify()
Documentation/i2c/smbus-protocol | 3 ++
drivers/i2c/i2c-smbus.c | 114 ++++++++++++++++++++++++++++++++++++---
include/linux/i2c-smbus.h | 43 +++++++++++++++
include/linux/i2c.h | 3 ++
include/uapi/linux/i2c.h | 1 +
5 files changed, 158 insertions(+), 6 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..e2abb26 100644
--- a/drivers/i2c/i2c-smbus.c
+++ b/drivers/i2c/i2c-smbus.c
@@ -19,7 +19,6 @@
#include <linux/module.h>
#include <linux/device.h>
#include <linux/interrupt.h>
-#include <linux/workqueue.h>
#include <linux/i2c.h>
#include <linux/i2c-smbus.h>
#include <linux/slab.h>
@@ -33,7 +32,8 @@ 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 +56,7 @@ 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 +96,9 @@ 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 +106,7 @@ 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 +240,108 @@ int i2c_handle_smbus_alert(struct i2c_client *ara)
}
EXPORT_SYMBOL_GPL(i2c_handle_smbus_alert);
+static void smbus_host_notify_work(struct work_struct *work)
+{
+ struct alert_data alert;
+ struct i2c_adapter *adapter;
+ unsigned long flags;
+ u16 payload;
+ u8 addr;
+ struct smbus_host_notify *data;
+
+ data = container_of(work, struct smbus_host_notify, work);
+
+ spin_lock_irqsave(&data->lock, flags);
+ payload = data->payload;
+ addr = data->addr;
+ adapter = data->adapter;
+
+ /* clear the pending bit and release the spinlock */
+ data->pending = false;
+ spin_unlock_irqrestore(&data->lock, flags);
+
+ if (!adapter || !addr)
+ return;
+
+ alert.type = I2C_PROTOCOL_SMBUS_HOST_NOTIFY;
+ alert.addr = addr;
+ alert.data = payload;
+
+ device_for_each_child(&adapter->dev, &alert, smbus_do_alert);
+}
+
+/**
+ * i2c_setup_smbus_host_notify - Allocate a new smbus_host_notify for the given
+ * I2C adapter.
+ * @adapter: the adapter we want to associate a Host Notify function
+ *
+ * Returns a struct smbus_host_notify pointer on success, and NULL on failure.
+ * The resulting smbus_host_notify must not be freed afterwards, it is a
+ * managed resource already.
+ */
+struct smbus_host_notify *i2c_setup_smbus_host_notify(struct i2c_adapter *adap)
+{
+ struct smbus_host_notify *host_notify;
+
+ host_notify = devm_kzalloc(&adap->dev, sizeof(struct smbus_host_notify),
+ GFP_KERNEL);
+ if (!host_notify)
+ return NULL;
+
+ host_notify->adapter = adap;
+
+ spin_lock_init(&host_notify->lock);
+ INIT_WORK(&host_notify->work, smbus_host_notify_work);
+
+ return host_notify;
+}
+EXPORT_SYMBOL_GPL(i2c_setup_smbus_host_notify);
+
+/**
+ * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct
+ * I2C client.
+ * @host_notify: the struct host_notify attached to the relevant adapter
+ * @data: the Host Notify data which contains the payload and address of the
+ * client
+ * Context: can't sleep
+ *
+ * Helper function to be called from an I2C bus driver's interrupt
+ * handler. It will schedule the Host Notify work, in turn calling the
+ * corresponding I2C device driver's alert function.
+ *
+ * host_notify should be a valid pointer previously returned by
+ * i2c_setup_smbus_host_notify().
+ */
+int i2c_handle_smbus_host_notify(struct smbus_host_notify *host_notify,
+ unsigned short addr, unsigned int data)
+{
+ unsigned long flags;
+ struct i2c_adapter *adapter;
+
+ if (!host_notify || !host_notify->adapter)
+ return -EINVAL;
+
+ adapter = host_notify->adapter;
+
+ spin_lock_irqsave(&host_notify->lock, flags);
+
+ if (host_notify->pending) {
+ spin_unlock_irqrestore(&host_notify->lock, flags);
+ dev_warn(&adapter->dev, "Host Notify already scheduled\n.");
+ return -EFAULT;
+ }
+
+ host_notify->payload = data;
+ host_notify->addr = addr;
+
+ /* Mark that there is a pending notification and release the lock */
+ host_notify->pending = true;
+ spin_unlock_irqrestore(&host_notify->lock, flags);
+
+ return schedule_work(&host_notify->work);
+}
+EXPORT_SYMBOL_GPL(i2c_handle_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..d2fbd19 100644
--- a/include/linux/i2c-smbus.h
+++ b/include/linux/i2c-smbus.h
@@ -23,6 +23,8 @@
#define _LINUX_I2C_SMBUS_H
#include <linux/i2c.h>
+#include <linux/spinlock.h>
+#include <linux/workqueue.h>
/**
@@ -48,4 +50,45 @@ 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);
+/**
+ * smbus_host_notify - internal structure used by the Host Notify mechanism.
+ * @adapter: the I2C adapter associated with this struct
+ * @work: worker used to schedule the IRQ in the slave device
+ * @lock: spinlock to check if a notification is already pending
+ * @pending: flag set when a notification is pending (any new notification will
+ * be rejected if pending is true)
+ * @payload: the actual payload of the Host Notify event
+ * @addr: the address of the slave device which raised the notification
+ *
+ * This struct needs to be allocated by i2c_setup_smbus_host_notify() and does
+ * not need to be freed. Internally, i2c_setup_smbus_host_notify() uses a
+ * managed resource to clean this up when the adapter get released.
+ */
+struct smbus_host_notify {
+ struct i2c_adapter *adapter;
+ struct work_struct work;
+ spinlock_t lock;
+ bool pending;
+ u16 payload;
+ u8 addr;
+};
+
+#if defined(CONFIG_I2C_SMBUS) || defined(CONFIG_I2C_SMBUS_MODULE)
+struct smbus_host_notify *i2c_setup_smbus_host_notify(struct i2c_adapter *adap);
+int i2c_handle_smbus_host_notify(struct smbus_host_notify *host_notify,
+ unsigned short addr, unsigned int data);
+#else
+static inline struct smbus_host_notify *
+i2c_setup_smbus_host_notify(struct i2c_adapter *adap)
+{
+ return NULL;
+}
+
+static inline int i2c_handle_smbus_host_notify(struct i2c_adapter *adapter,
+ unsigned short addr, unsigned int data)
+{
+ return 0;
+}
+#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
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v4 3/3] i2c: i801: add support of Host Notify
2015-07-23 18:55 ` Benjamin Tissoires
` (2 preceding siblings ...)
(?)
@ 2015-07-23 18:55 ` Benjamin Tissoires
-1 siblings, 0 replies; 8+ messages in thread
From: Benjamin Tissoires @ 2015-07-23 18:55 UTC (permalink / raw
To: Wolfram Sang, Jean Delvare, Dmitry Torokhov
Cc: benjamin.tissoires, linux-i2c, linux-kernel, 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)
no changes in v3
changes in v4:
- make use of the new API -> no more worker spawning here
- solved a race between the access of the Host Notify registers and the actual
I2C transfers.
drivers/i2c/busses/i2c-i801.c | 164 +++++++++++++++++++++++++++++++-----------
1 file changed, 121 insertions(+), 43 deletions(-)
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 5ecbb3f..752f236 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 smbus_host_notify *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. */
@@ -479,8 +498,23 @@ static void i801_isr_byte_done(struct i801_priv *priv)
outb_p(SMBHSTSTS_BYTE_DONE, SMBHSTSTS(priv));
}
+static irqreturn_t i801_host_notify_isr(struct i801_priv *priv)
+{
+ unsigned short addr;
+ unsigned int data;
+
+ addr = inb_p(SMBNTFDADD(priv)) >> 1;
+ data = inw_p(SMBNTFDDAT(priv));
+
+ i2c_handle_smbus_host_notify(priv->host_notify, addr, data);
+
+ /* clear Host Notify bit and return */
+ outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv));
+ return IRQ_HANDLED;
+}
+
/*
- * There are two kinds of interrupts:
+ * There are three kinds of interrupts:
*
* 1) i801 signals transaction completion with one of these interrupts:
* INTR - Success
@@ -492,6 +526,8 @@ 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 +540,12 @@ 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 +843,29 @@ 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 int i801_enable_host_notify(struct i2c_adapter *adapter)
+{
+ struct i801_priv *priv = i2c_get_adapdata(adapter);
+
+ if (!(priv->features & FEATURE_HOST_NOTIFY))
+ return -ENOTSUPP;
+
+ if (!priv->host_notify)
+ priv->host_notify = i2c_setup_smbus_host_notify(adapter);
+
+ if (!priv->host_notify)
+ return -ENOMEM;
+
+ 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));
+
+ return 0;
}
static const struct i2c_algorithm smbus_algorithm = {
@@ -1166,6 +1230,8 @@ 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:
@@ -1279,6 +1345,15 @@ 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.
+ */
+ err = i801_enable_host_notify(&priv->adapter);
+ if (err && err != -ENOTSUPP)
+ dev_warn(&dev->dev, "Unable to enable SMBus Host Notify\n");
+
i801_probe_optional_slaves(priv);
/* We ignore errors - multiplexing is optional */
i801_add_mux(priv);
@@ -1315,8 +1390,11 @@ 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
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH v4 0/3] I2C/SMBus: add support for Host Notify (in i2c_i801)
2015-07-23 18:55 ` Benjamin Tissoires
` (3 preceding siblings ...)
(?)
@ 2015-09-22 17:41 ` Benjamin Tissoires
2015-09-23 9:16 ` Jean Delvare
-1 siblings, 1 reply; 8+ messages in thread
From: Benjamin Tissoires @ 2015-09-22 17:41 UTC (permalink / raw
To: Wolfram Sang, Jean Delvare, Dmitry Torokhov; +Cc: linux-i2c, linux-kernel
Hi All,
any estimate when anybody will be able to review this series?
Cheers,
Benjamin
On Jul 23 2015 or thereabouts, Benjamin Tissoires wrote:
> Hi,
>
> this is the v4 of this patch series which fixes the race we discovered this
> week when accessing the registers in i2c_i801.
>
> Compared to v3, i2c_handle_smbus_host_notify can now be called in a non sleeping
> thread because a worker will be spawn later on.
> That also means that we need to allocate the worker and some other structures,
> so I introduced i2c_setup_smbus_host_notify().
>
> 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/hwmon/lm90.c | 3 +-
> drivers/i2c/busses/i2c-i801.c | 164 +++++++++++++++++++++++++++++----------
> drivers/i2c/i2c-smbus.c | 113 +++++++++++++++++++++++++--
> include/linux/i2c-smbus.h | 43 ++++++++++
> include/linux/i2c.h | 10 ++-
> include/uapi/linux/i2c.h | 1 +
> 8 files changed, 292 insertions(+), 51 deletions(-)
>
> --
> 2.4.3
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v4 0/3] I2C/SMBus: add support for Host Notify (in i2c_i801)
2015-09-22 17:41 ` [PATCH v4 0/3] I2C/SMBus: add support for Host Notify (in i2c_i801) Benjamin Tissoires
@ 2015-09-23 9:16 ` Jean Delvare
0 siblings, 0 replies; 8+ messages in thread
From: Jean Delvare @ 2015-09-23 9:16 UTC (permalink / raw
To: Benjamin Tissoires; +Cc: Wolfram Sang, Dmitry Torokhov, linux-i2c, linux-kernel
On Tue, 22 Sep 2015 13:41:27 -0400, Benjamin Tissoires wrote:
> Hi All,
>
> any estimate when anybody will be able to review this series?
It's on my to-do list, hopefully this week or early next week. For the
core part it's probably better if Wolfram can do the review.
--
Jean Delvare
SUSE L3 Support
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2015-09-23 9:16 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2015-07-23 18:55 [PATCH v4 0/3] I2C/SMBus: add support for Host Notify (in i2c_i801) Benjamin Tissoires
2015-07-23 18:55 ` Benjamin Tissoires
2015-07-23 18:55 ` [PATCH v4 1/3] i2c: add a protocol parameter to the alert callback Benjamin Tissoires
2015-07-23 18:55 ` Benjamin Tissoires
2015-07-23 18:55 ` [PATCH v4 2/3] i2c-smbus: add SMBus Host Notify support Benjamin Tissoires
2015-07-23 18:55 ` [PATCH v4 3/3] i2c: i801: add support of Host Notify Benjamin Tissoires
2015-09-22 17:41 ` [PATCH v4 0/3] I2C/SMBus: add support for Host Notify (in i2c_i801) Benjamin Tissoires
2015-09-23 9:16 ` Jean Delvare
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