[PATCH v7 0/6] I2C IRQ Probe Improvements

[PATCH v7 0/6] I2C IRQ Probe Improvements

[Charles Keepax]

This series attempts to align as much IRQ handling into the
probe path as possible. Note that I don't have a great setup
for testing these patches so they are mostly just build tested
and need careful review and testing before any of them are
merged.

The series brings the ACPI path inline with the way the device
tree path handles the IRQ entirely at probe time. However,
it still leaves any IRQ specified through the board_info as
being handled at device time. In that case we need to cache
something from the board_info until probe time, which leaves
any alternative solution with something basically the same as
the current handling although perhaps caching more stuff.

Thanks,
Charles

See previous discussions:
 - https://lkml.org/lkml/2019/2/15/989
 - https://www.spinics.net/lists/linux-i2c/msg39541.html

Charles Keepax (6):
  i2c: core: Allow whole core to use i2c_dev_irq_from_resources
  i2c: acpi: Use available IRQ helper functions
  i2c: acpi: Factor out getting the IRQ from ACPI
  i2c: core: Move ACPI IRQ handling to probe time
  i2c: core: Move ACPI gpio IRQ handling into i2c_acpi_get_irq
  i2c: core: Tidy up handling of init_irq

 drivers/i2c/i2c-core-acpi.c | 59 ++++++++++++++++++++++++++++++++-------------
 drivers/i2c/i2c-core-base.c | 11 +++++----
 drivers/i2c/i2c-core.h      |  9 +++++++
 3 files changed, 57 insertions(+), 22 deletions(-)

-- 
2.11.0

[PATCH v7 1/6] i2c: core: Allow whole core to use i2c_dev_irq_from_resources

[Charles Keepax]

Remove the static from i2c_dev_irq_from _resources so that other parts
of the core code can use this helper function.

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
---

No change since v6.

Thanks,
Charles

 drivers/i2c/i2c-core-base.c | 4 ++--
 drivers/i2c/i2c-core.h      | 2 ++
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 2569e97f9bf35..8a303246d534b 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -679,8 +679,8 @@ static void i2c_dev_set_name(struct i2c_adapter *adap,
 		     i2c_encode_flags_to_addr(client));
 }
 
-static int i2c_dev_irq_from_resources(const struct resource *resources,
-				      unsigned int num_resources)
+int i2c_dev_irq_from_resources(const struct resource *resources,
+			       unsigned int num_resources)
 {
 	struct irq_data *irqd;
 	int i;
diff --git a/drivers/i2c/i2c-core.h b/drivers/i2c/i2c-core.h
index 851c11b4c0f3a..2a3b28bf826b1 100644
--- a/drivers/i2c/i2c-core.h
+++ b/drivers/i2c/i2c-core.h
@@ -19,6 +19,8 @@ extern struct list_head	__i2c_board_list;
 extern int		__i2c_first_dynamic_bus_num;
 
 int i2c_check_7bit_addr_validity_strict(unsigned short addr);
+int i2c_dev_irq_from_resources(const struct resource *resources,
+			       unsigned int num_resources);
 
 /*
  * We only allow atomic transfers for very late communication, e.g. to send
-- 
2.11.0

[PATCH v7 2/6] i2c: acpi: Use available IRQ helper functions

[Charles Keepax]

Use the available IRQ helper functions, most of the functions have
additional helpful side affects like configuring the trigger type of the
IRQ.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
---

No change since v6.

Thanks,
Charles

 drivers/i2c/i2c-core-acpi.c | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index f1d648962b223..3951e352317ff 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -133,13 +133,24 @@ static int i2c_acpi_do_lookup(struct acpi_device *adev,
 	return 0;
 }
 
+static int i2c_acpi_add_resource(struct acpi_resource *ares, void *data)
+{
+	int *irq = data;
+	struct resource r;
+
+	if (*irq <= 0 && acpi_dev_resource_interrupt(ares, 0, &r))
+		*irq = i2c_dev_irq_from_resources(&r, 1);
+
+	/* No need to add resource to the list, free list if this changes */
+	return 1;
+}
+
 static int i2c_acpi_get_info(struct acpi_device *adev,
 			     struct i2c_board_info *info,
 			     struct i2c_adapter *adapter,
 			     acpi_handle *adapter_handle)
 {
 	struct list_head resource_list;
-	struct resource_entry *entry;
 	struct i2c_acpi_lookup lookup;
 	int ret;
 
@@ -172,19 +183,11 @@ static int i2c_acpi_get_info(struct acpi_device *adev,
 
 	/* Then fill IRQ number if any */
 	INIT_LIST_HEAD(&resource_list);
-	ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
+	ret = acpi_dev_get_resources(adev, &resource_list,
+				     i2c_acpi_add_resource, &info->irq);
 	if (ret < 0)
 		return -EINVAL;
 
-	resource_list_for_each_entry(entry, &resource_list) {
-		if (resource_type(entry->res) == IORESOURCE_IRQ) {
-			info->irq = entry->res->start;
-			break;
-		}
-	}
-
-	acpi_dev_free_resource_list(&resource_list);
-
 	acpi_set_modalias(adev, dev_name(&adev->dev), info->type,
 			  sizeof(info->type));
 
-- 
2.11.0

[PATCH v7 3/6] i2c: acpi: Factor out getting the IRQ from ACPI

[Charles Keepax]

In preparation for future refactoring factor out the fetch of the IRQ
into its own helper function. Whilst we are at it update the handling
to return the actual error code returned from acpi_dev_get_resources
as well.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
---

No change since v6.

Thanks,
Charles

 drivers/i2c/i2c-core-acpi.c | 27 +++++++++++++++++++++------
 1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index 3951e352317ff..c91492eaacd93 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -145,12 +145,29 @@ static int i2c_acpi_add_resource(struct acpi_resource *ares, void *data)
 	return 1;
 }
 
+static int i2c_acpi_get_irq(struct acpi_device *adev)
+{
+	struct list_head resource_list;
+	int irq = -ENOENT;
+	int ret;
+
+	INIT_LIST_HEAD(&resource_list);
+
+	ret = acpi_dev_get_resources(adev, &resource_list,
+				     i2c_acpi_add_resource, &irq);
+	if (ret < 0)
+		return ret;
+
+	acpi_dev_free_resource_list(&resource_list);
+
+	return irq;
+}
+
 static int i2c_acpi_get_info(struct acpi_device *adev,
 			     struct i2c_board_info *info,
 			     struct i2c_adapter *adapter,
 			     acpi_handle *adapter_handle)
 {
-	struct list_head resource_list;
 	struct i2c_acpi_lookup lookup;
 	int ret;
 
@@ -182,11 +199,9 @@ static int i2c_acpi_get_info(struct acpi_device *adev,
 		*adapter_handle = lookup.adapter_handle;
 
 	/* Then fill IRQ number if any */
-	INIT_LIST_HEAD(&resource_list);
-	ret = acpi_dev_get_resources(adev, &resource_list,
-				     i2c_acpi_add_resource, &info->irq);
-	if (ret < 0)
-		return -EINVAL;
+	info->irq = i2c_acpi_get_irq(adev);
+	if (info->irq < 0)
+		return info->irq;
 
 	acpi_set_modalias(adev, dev_name(&adev->dev), info->type,
 			  sizeof(info->type));
-- 
2.11.0

[PATCH v7 4/6] i2c: core: Move ACPI IRQ handling to probe time

[Charles Keepax]

Bring the ACPI path in sync with the device tree path and handle all the
IRQ fetching at probe time. This leaves the only IRQ handling at device
registration time being that which is passed directly through the board
info as either a resource or an actual IRQ number.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
---

Changes since v6:
 - Squashed back in "Make i2c_acpi_get_irq available to the rest of the I2C core"
 - Switched back to using the i2c_client device for the API

Thanks,
Charles

 drivers/i2c/i2c-core-acpi.c | 16 ++++++++++------
 drivers/i2c/i2c-core-base.c |  5 ++++-
 drivers/i2c/i2c-core.h      |  7 +++++++
 3 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index c91492eaacd93..e7559b3853062 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -145,8 +145,17 @@ static int i2c_acpi_add_resource(struct acpi_resource *ares, void *data)
 	return 1;
 }
 
-static int i2c_acpi_get_irq(struct acpi_device *adev)
+/**
+ * i2c_acpi_get_irq - get device IRQ number from ACPI
+ * @client: Pointer to the I2C client device
+ *
+ * Find the IRQ number used by a specific client device.
+ *
+ * Return: The IRQ number or an error code.
+ */
+int i2c_acpi_get_irq(struct i2c_client *client)
 {
+	struct acpi_device *adev = ACPI_COMPANION(&client->dev);
 	struct list_head resource_list;
 	int irq = -ENOENT;
 	int ret;
@@ -198,11 +207,6 @@ static int i2c_acpi_get_info(struct acpi_device *adev,
 	if (adapter_handle)
 		*adapter_handle = lookup.adapter_handle;
 
-	/* Then fill IRQ number if any */
-	info->irq = i2c_acpi_get_irq(adev);
-	if (info->irq < 0)
-		return info->irq;
-
 	acpi_set_modalias(adev, dev_name(&adev->dev), info->type,
 			  sizeof(info->type));
 
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 8a303246d534b..c848b325969e9 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -327,7 +327,10 @@ static int i2c_device_probe(struct device *dev)
 			if (irq == -EINVAL || irq == -ENODATA)
 				irq = of_irq_get(dev->of_node, 0);
 		} else if (ACPI_COMPANION(dev)) {
-			irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0);
+			irq = i2c_acpi_get_irq(client);
+
+			if (irq == -ENOENT)
+				irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0);
 		}
 		if (irq == -EPROBE_DEFER)
 			return irq;
diff --git a/drivers/i2c/i2c-core.h b/drivers/i2c/i2c-core.h
index 2a3b28bf826b1..517d98be68d25 100644
--- a/drivers/i2c/i2c-core.h
+++ b/drivers/i2c/i2c-core.h
@@ -63,6 +63,8 @@ const struct acpi_device_id *
 i2c_acpi_match_device(const struct acpi_device_id *matches,
 		      struct i2c_client *client);
 void i2c_acpi_register_devices(struct i2c_adapter *adap);
+
+int i2c_acpi_get_irq(struct i2c_client *client);
 #else /* CONFIG_ACPI */
 static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
 static inline const struct acpi_device_id *
@@ -71,6 +73,11 @@ i2c_acpi_match_device(const struct acpi_device_id *matches,
 {
 	return NULL;
 }
+
+static inline int i2c_acpi_get_irq(struct i2c_client *client)
+{
+	return 0;
+}
 #endif /* CONFIG_ACPI */
 extern struct notifier_block i2c_acpi_notifier;
 
-- 
2.11.0

[PATCH v7 5/6] i2c: core: Move ACPI gpio IRQ handling into i2c_acpi_get_irq

[Charles Keepax]

It makes sense to contain all the ACPI IRQ handling in a single helper
function.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
---

No change since v6.

Thanks,
Charles

 drivers/i2c/i2c-core-acpi.c | 3 +++
 drivers/i2c/i2c-core-base.c | 3 ---
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index e7559b3853062..99f22a93c059f 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -169,6 +169,9 @@ int i2c_acpi_get_irq(struct i2c_client *client)
 
 	acpi_dev_free_resource_list(&resource_list);
 
+	if (irq == -ENOENT)
+		irq = acpi_dev_gpio_irq_get(adev, 0);
+
 	return irq;
 }
 
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index c848b325969e9..1bf7d8748de14 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -328,9 +328,6 @@ static int i2c_device_probe(struct device *dev)
 				irq = of_irq_get(dev->of_node, 0);
 		} else if (ACPI_COMPANION(dev)) {
 			irq = i2c_acpi_get_irq(client);
-
-			if (irq == -ENOENT)
-				irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0);
 		}
 		if (irq == -EPROBE_DEFER)
 			return irq;
-- 
2.11.0

[PATCH v7 6/6] i2c: core: Tidy up handling of init_irq

[Charles Keepax]

Only set init_irq during i2c_device_new and only handle client->irq on
the probe/remove paths.

Suggested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
---

No change since v6.

Thanks,
Charles

 drivers/i2c/i2c-core-base.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 1bf7d8748de14..aeb3e0508186b 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -314,6 +314,8 @@ static int i2c_device_probe(struct device *dev)
 
 	driver = to_i2c_driver(dev->driver);
 
+	client->irq = client->init_irq;
+
 	if (!client->irq && !driver->disable_i2c_core_irq_mapping) {
 		int irq = -ENOENT;
 
@@ -424,7 +426,7 @@ static int i2c_device_remove(struct device *dev)
 	dev_pm_clear_wake_irq(&client->dev);
 	device_init_wakeup(&client->dev, false);
 
-	client->irq = client->init_irq;
+	client->irq = 0;
 	if (client->flags & I2C_CLIENT_HOST_NOTIFY)
 		pm_runtime_put(&client->adapter->dev);
 
@@ -741,7 +743,6 @@ i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *inf
 	if (!client->init_irq)
 		client->init_irq = i2c_dev_irq_from_resources(info->resources,
 							 info->num_resources);
-	client->irq = client->init_irq;
 
 	strlcpy(client->name, info->type, sizeof(client->name));
 
-- 
2.11.0

Re: [PATCH v7 2/6] i2c: acpi: Use available IRQ helper functions

[Andy Shevchenko]

On Wed, Jun 26, 2019 at 04:02:58PM +0100, Charles Keepax wrote:
> Use the available IRQ helper functions, most of the functions have
> additional helpful side affects like configuring the trigger type of the
> IRQ.

> -	acpi_dev_free_resource_list(&resource_list);

I have thought that we can drop completely the resource_list, though ACPI
doesn't allow this. So, I would rather withdraw this change to be on the safe
(symmetrical) side.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v7 0/6] I2C IRQ Probe Improvements

[Andy Shevchenko]

On Wed, Jun 26, 2019 at 04:02:56PM +0100, Charles Keepax wrote:
> This series attempts to align as much IRQ handling into the
> probe path as possible. Note that I don't have a great setup
> for testing these patches so they are mostly just build tested
> and need careful review and testing before any of them are
> merged.
> 
> The series brings the ACPI path inline with the way the device
> tree path handles the IRQ entirely at probe time. However,
> it still leaves any IRQ specified through the board_info as
> being handled at device time. In that case we need to cache
> something from the board_info until probe time, which leaves
> any alternative solution with something basically the same as
> the current handling although perhaps caching more stuff.
> 

Thanks!
After addressing one comment, take my

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

for all patches which lack it now.

> Thanks,
> Charles
> 
> See previous discussions:
>  - https://lkml.org/lkml/2019/2/15/989
>  - https://www.spinics.net/lists/linux-i2c/msg39541.html
> 
> Charles Keepax (6):
>   i2c: core: Allow whole core to use i2c_dev_irq_from_resources
>   i2c: acpi: Use available IRQ helper functions
>   i2c: acpi: Factor out getting the IRQ from ACPI
>   i2c: core: Move ACPI IRQ handling to probe time
>   i2c: core: Move ACPI gpio IRQ handling into i2c_acpi_get_irq
>   i2c: core: Tidy up handling of init_irq
> 
>  drivers/i2c/i2c-core-acpi.c | 59 ++++++++++++++++++++++++++++++++-------------
>  drivers/i2c/i2c-core-base.c | 11 +++++----
>  drivers/i2c/i2c-core.h      |  9 +++++++
>  3 files changed, 57 insertions(+), 22 deletions(-)
> 
> -- 
> 2.11.0
> 

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v7 2/6] i2c: acpi: Use available IRQ helper functions

[Charles Keepax]

On Wed, Jun 26, 2019 at 10:09:06PM +0300, Andy Shevchenko wrote:
> On Wed, Jun 26, 2019 at 04:02:58PM +0100, Charles Keepax wrote:
> > Use the available IRQ helper functions, most of the functions have
> > additional helpful side affects like configuring the trigger type of the
> > IRQ.
> 
> > -	acpi_dev_free_resource_list(&resource_list);
> 
> I have thought that we can drop completely the resource_list, though ACPI
> doesn't allow this. So, I would rather withdraw this change to be on the safe
> (symmetrical) side.
> 

Yeah would be my preference as well, will do another spin.

Thanks,
Charles

Re: [PATCH v7 0/6] I2C IRQ Probe Improvements

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 1145 bytes --]

On Wed, Jun 26, 2019 at 04:02:56PM +0100, Charles Keepax wrote:
> This series attempts to align as much IRQ handling into the
> probe path as possible. Note that I don't have a great setup
> for testing these patches so they are mostly just build tested
> and need careful review and testing before any of them are
> merged.
> 
> The series brings the ACPI path inline with the way the device
> tree path handles the IRQ entirely at probe time. However,
> it still leaves any IRQ specified through the board_info as
> being handled at device time. In that case we need to cache
> something from the board_info until probe time, which leaves
> any alternative solution with something basically the same as
> the current handling although perhaps caching more stuff.

Ehrm, I somehow lost the cover-letter from v8, so I am replying here.
Sorry for the noise.

So, since all patches have the review from Mika and Andy (thanks!), I
applied v8 now to for-next. I had a glimpse, too, and thought it was
ready to go. But I didn't really review myself, I trust you guys. Thank
you, Charles, for your efforts working on this one!


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