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I2C IRQ Probe Improvements

PATCH In review Charles Keepax 2 participants 11 messages Jun 27, 2019

Subsystems (4)
ACPI I2C subsystem host drivers I2C I2C ACPI support
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Charles Keepax

author
#0 lore raw

v8 cover I2C IRQ Probe Improvements

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 | 58 ++++++++++++++++++++++++++++++++-------------
 drivers/i2c/i2c-core-base.c | 11 +++++----
 drivers/i2c/i2c-core.h      |  9 +++++++
 3 files changed, 56 insertions(+), 22 deletions(-)
Signature · 1 line
2.11.0
author
#1 lore raw

PATCH v8 1/6 i2c: core: Allow whole core to use i2c_dev_irq_from_resources

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 <[email protected]>
Reviewed-by Andy Shevchenko <[email protected]>
Signed-off-by Charles Keepax <[email protected]>

---

No change since v7.

Thanks,
Charles

 drivers/i2c/i2c-core-base.c | 4 ++--
 drivers/i2c/i2c-core.h      | 2 ++
 2 files changed, 4 insertions(+), 2 deletions(-)
drivers/i2c/i2c-core-base.c +2 -2
index e77bab2fb4670..2a0a9cc8b8fbd 100644
@@ -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;
drivers/i2c/i2c-core.h +2 -0
index 851c11b4c0f3a..2a3b28bf826b1 100644
@@ -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
Signature · 1 line
2.11.0
author
#2 lore raw

PATCH v8 2/6 i2c: acpi: Use available IRQ helper functions

In reply to 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.

Reviewed-by Andy Shevchenko <[email protected]>
Signed-off-by Charles Keepax <[email protected]>

---

Changes since v7:
- Leave call to acpi_dev_free_resource_list

Thanks,
Charles

 drivers/i2c/i2c-core-acpi.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)
drivers/i2c/i2c-core-acpi.c +13 -9
index f1d648962b223..1820f18a4e5f9 100644
@@ -133,13 +133,23 @@ 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);
+
+	return 1; /* No need to add resource to the list */
+}
+
 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;
 

@@ -172,17 +182,11 @@ 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,
Signature · 1 line
2.11.0
author
#4 lore raw

PATCH v8 3/6 i2c: acpi: Factor out getting the IRQ from ACPI

In reply to 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.

Reviewed-by Andy Shevchenko <[email protected]>
Signed-off-by Charles Keepax <[email protected]>

---

Changes since v7:
- Leave call to acpi_dev_free_resource_list

Thanks,
Charles

 drivers/i2c/i2c-core-acpi.c | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)
drivers/i2c/i2c-core-acpi.c +21 -8
index 1820f18a4e5f9..3eb65f113c13b 100644
@@ -144,12 +144,29 @@ static int i2c_acpi_add_resource(struct acpi_resource *ares, void *data)
 	return 1; /* No need to add resource to the list */
 }
 
+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;
 

@@ -181,13 +198,9 @@ 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;
-
-	acpi_dev_free_resource_list(&resource_list);
+	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));
Signature · 1 line
2.11.0
Reviewed-by on v8 3/6
#5 lore raw

Re: [PATCH v8 3/6] i2c: acpi: Factor out getting the IRQ from ACPI

Quoted 7 lines · 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.

Reviewed-by Andy Shevchenko <[email protected]>
Signed-off-by Charles Keepax <[email protected]>
Reviewed-by Mika Westerberg <[email protected]>
author
#6 lore raw

PATCH v8 4/6 i2c: core: Move ACPI IRQ handling to probe time

In reply to 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.

Reviewed-by Andy Shevchenko <[email protected]>
Signed-off-by Charles Keepax <[email protected]>

---

No change since v7.

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(-)
drivers/i2c/i2c-core-acpi.c +10 -6
index 3eb65f113c13b..eaf45cf8e5b91 100644
@@ -144,8 +144,17 @@ static int i2c_acpi_add_resource(struct acpi_resource *ares, void *data)
 	return 1; /* No need to add resource to the list */
 }
 
-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;

@@ -197,11 +206,6 @@ 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));
drivers/i2c/i2c-core-base.c +4 -1
index 2a0a9cc8b8fbd..c8fa2b825dcef 100644
@@ -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;
drivers/i2c/i2c-core.h +7 -0
index 2a3b28bf826b1..517d98be68d25 100644
@@ -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;
Signature · 1 line
2.11.0
Reviewed-by on v8 4/6
#7 lore raw

Re: [PATCH v8 4/6] i2c: core: Move ACPI IRQ handling to probe time

Quoted 7 lines · 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.

Reviewed-by Andy Shevchenko <[email protected]>
Signed-off-by Charles Keepax <[email protected]>
Reviewed-by Mika Westerberg <[email protected]>
author
#8 lore raw

PATCH v8 5/6 i2c: core: Move ACPI gpio IRQ handling into i2c_acpi_get_irq

In reply to Charles Keepax

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

Reviewed-by Andy Shevchenko <[email protected]>
Signed-off-by Charles Keepax <[email protected]>

---

No change since v7.

Thanks,
Charles

 drivers/i2c/i2c-core-acpi.c | 3 +++
 drivers/i2c/i2c-core-base.c | 3 ---
 2 files changed, 3 insertions(+), 3 deletions(-)
drivers/i2c/i2c-core-acpi.c +3 -0
index eaf45cf8e5b91..3707823efa850 100644
@@ -168,6 +168,9 @@ 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;
 }
drivers/i2c/i2c-core-base.c +0 -3
index c8fa2b825dcef..f0e1d338c7ddf 100644
@@ -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;
Signature · 1 line
2.11.0
author
#10 lore raw

PATCH v8 6/6 i2c: core: Tidy up handling of init_irq

In reply to Charles Keepax

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

Suggested-by Benjamin Tissoires <[email protected]>
Reviewed-by Mika Westerberg <[email protected]>
Reviewed-by Andy Shevchenko <[email protected]>
Signed-off-by Charles Keepax <[email protected]>
---
 drivers/i2c/i2c-core-base.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
drivers/i2c/i2c-core-base.c +3 -2
index f0e1d338c7ddf..f26ed495d3842 100644
@@ -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));
Signature · 1 line
2.11.0