[12/15] i2c: core: Add new i2c_acpi_new_device helper function

Message ID 20170317095527.10487-13-hdegoede@redhat.com
State Superseded
Headers show

Commit Message

Hans de Goede March 17, 2017, 9:55 a.m.
By default the i2c subsys creates an i2c-client for the first I2cSerialBus
resource of an acpi_device, but some acpi_devices have multiple
I2cSerialBus resources and the driver may need access to the others.

This commit adds a new i2c_acpi_new_device function which can be used by
drivers to create an i2c-client for any (other) I2cSerialBus resource of
an acpi_device.

Note that the other resources may even be on a different i2c bus, so just
retrieving the client address is not enough.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/i2c/i2c-core.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/i2c.h    |  5 +++++
 2 files changed, 53 insertions(+)

Comments

Andy Shevchenko March 17, 2017, 5:37 p.m. | #1
On Fri, 2017-03-17 at 10:55 +0100, Hans de Goede wrote:
> By default the i2c subsys creates an i2c-client for the first
> I2cSerialBus
> resource of an acpi_device, but some acpi_devices have multiple
> I2cSerialBus resources and the driver may need access to the others.
> 
> This commit adds a new i2c_acpi_new_device function which can be used
> by
> drivers to create an i2c-client for any (other) I2cSerialBus resource
> of
> an acpi_device.
> 
> Note that the other resources may even be on a different i2c bus, so
> just
> retrieving the client address is not enough.
> 

Looks sane to me:

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

Nevertheless, one nit, can you update commit message with real excerpt
of DSDT?

> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  drivers/i2c/i2c-core.c | 48
> ++++++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/i2c.h    |  5 +++++
>  2 files changed, 53 insertions(+)
> 
> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
> index 32b58fb..fd45207 100644
> --- a/drivers/i2c/i2c-core.c
> +++ b/drivers/i2c/i2c-core.c
> @@ -421,6 +421,54 @@ static int i2c_acpi_notify(struct notifier_block
> *nb, unsigned long value,
>  static struct notifier_block i2c_acpi_notifier = {
>  	.notifier_call = i2c_acpi_notify,
>  };
> +
> +/**
> + * i2c_acpi_new_device - Create i2c client for the Nth acpi resource
> of dev
> + * @dev:     Device owning the acpi resources to get the client from
> + * @index:   Index of acpi resource to get
> + *
> + * By default the i2c subsys creates an i2c-client for the first
> I2cSerialBus
> + * resource of an acpi_device, but some acpi_devices have multiple
> + * I2cSerialBus resources and the driver may need access to the
> others.
> + * This function can be used by drivers to create an i2c-client for
> any
> + * resource of an acpi_device.
> + *
> + * Returns a pointer to the new i2c-client, or NULL if the resource
> or
> + * adapter were not found.
> + */
> +struct i2c_client *i2c_acpi_new_device(struct device *dev, int index)
> +{
> +	struct i2c_acpi_lookup lookup;
> +	struct i2c_board_info info;
> +	struct i2c_adapter *adapter;
> +	struct acpi_device *adev;
> +	LIST_HEAD(resource_list);
> +	int ret;
> +
> +	adev = ACPI_COMPANION(dev);
> +	if (!adev)
> +		return NULL;
> +
> +	memset(&info, 0, sizeof(info));
> +	memset(&lookup, 0, sizeof(lookup));
> +	lookup.info = &info;
> +	lookup.device_handle = acpi_device_handle(adev);
> +	lookup.index = index;
> +
> +	ret = acpi_dev_get_resources(adev, &resource_list,
> +				     i2c_acpi_fill_info, &lookup);
> +	acpi_dev_free_resource_list(&resource_list);
> +
> +	if (ret < 0 || !info.addr)
> +		return NULL;
> +
> +	adapter =
> i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
> +	if (!adapter)
> +		return NULL;
> +
> +	return i2c_new_device(adapter, &info);
> +}
> +EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
>  #else /* CONFIG_ACPI */
>  static inline void i2c_acpi_register_devices(struct i2c_adapter
> *adap) { }
>  extern struct notifier_block i2c_acpi_notifier;
> diff --git a/include/linux/i2c.h b/include/linux/i2c.h
> index 6b18352..369ebfa 100644
> --- a/include/linux/i2c.h
> +++ b/include/linux/i2c.h
> @@ -824,11 +824,16 @@ static inline const struct of_device_id
>  
>  #if IS_ENABLED(CONFIG_ACPI)
>  u32 i2c_acpi_find_bus_speed(struct device *dev);
> +struct i2c_client *i2c_acpi_new_device(struct device *dev, int
> index);
>  #else
>  static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
>  {
>  	return 0;
>  }
> +static inline struct i2c_client *i2c_acpi_new_device(struct device
> *d, int i)
> +{
> +	return NULL;
> +}
>  #endif /* CONFIG_ACPI */
>  
>  #endif /* _LINUX_I2C_H */
Hans de Goede March 22, 2017, 3:59 p.m. | #2
Hi,

On 17-03-17 18:37, Andy Shevchenko wrote:
> On Fri, 2017-03-17 at 10:55 +0100, Hans de Goede wrote:
>> By default the i2c subsys creates an i2c-client for the first
>> I2cSerialBus
>> resource of an acpi_device, but some acpi_devices have multiple
>> I2cSerialBus resources and the driver may need access to the others.
>>
>> This commit adds a new i2c_acpi_new_device function which can be used
>> by
>> drivers to create an i2c-client for any (other) I2cSerialBus resource
>> of
>> an acpi_device.
>>
>> Note that the other resources may even be on a different i2c bus, so
>> just
>> retrieving the client address is not enough.
>>
>
> Looks sane to me:
>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
>
> Nevertheless, one nit, can you update commit message with real excerpt
> of DSDT?

Sure, will do for v2.

Regards,

Hans


>
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
>>  drivers/i2c/i2c-core.c | 48
>> ++++++++++++++++++++++++++++++++++++++++++++++++
>>  include/linux/i2c.h    |  5 +++++
>>  2 files changed, 53 insertions(+)
>>
>> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
>> index 32b58fb..fd45207 100644
>> --- a/drivers/i2c/i2c-core.c
>> +++ b/drivers/i2c/i2c-core.c
>> @@ -421,6 +421,54 @@ static int i2c_acpi_notify(struct notifier_block
>> *nb, unsigned long value,
>>  static struct notifier_block i2c_acpi_notifier = {
>>  	.notifier_call = i2c_acpi_notify,
>>  };
>> +
>> +/**
>> + * i2c_acpi_new_device - Create i2c client for the Nth acpi resource
>> of dev
>> + * @dev:     Device owning the acpi resources to get the client from
>> + * @index:   Index of acpi resource to get
>> + *
>> + * By default the i2c subsys creates an i2c-client for the first
>> I2cSerialBus
>> + * resource of an acpi_device, but some acpi_devices have multiple
>> + * I2cSerialBus resources and the driver may need access to the
>> others.
>> + * This function can be used by drivers to create an i2c-client for
>> any
>> + * resource of an acpi_device.
>> + *
>> + * Returns a pointer to the new i2c-client, or NULL if the resource
>> or
>> + * adapter were not found.
>> + */
>> +struct i2c_client *i2c_acpi_new_device(struct device *dev, int index)
>> +{
>> +	struct i2c_acpi_lookup lookup;
>> +	struct i2c_board_info info;
>> +	struct i2c_adapter *adapter;
>> +	struct acpi_device *adev;
>> +	LIST_HEAD(resource_list);
>> +	int ret;
>> +
>> +	adev = ACPI_COMPANION(dev);
>> +	if (!adev)
>> +		return NULL;
>> +
>> +	memset(&info, 0, sizeof(info));
>> +	memset(&lookup, 0, sizeof(lookup));
>> +	lookup.info = &info;
>> +	lookup.device_handle = acpi_device_handle(adev);
>> +	lookup.index = index;
>> +
>> +	ret = acpi_dev_get_resources(adev, &resource_list,
>> +				     i2c_acpi_fill_info, &lookup);
>> +	acpi_dev_free_resource_list(&resource_list);
>> +
>> +	if (ret < 0 || !info.addr)
>> +		return NULL;
>> +
>> +	adapter =
>> i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
>> +	if (!adapter)
>> +		return NULL;
>> +
>> +	return i2c_new_device(adapter, &info);
>> +}
>> +EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
>>  #else /* CONFIG_ACPI */
>>  static inline void i2c_acpi_register_devices(struct i2c_adapter
>> *adap) { }
>>  extern struct notifier_block i2c_acpi_notifier;
>> diff --git a/include/linux/i2c.h b/include/linux/i2c.h
>> index 6b18352..369ebfa 100644
>> --- a/include/linux/i2c.h
>> +++ b/include/linux/i2c.h
>> @@ -824,11 +824,16 @@ static inline const struct of_device_id
>>
>>  #if IS_ENABLED(CONFIG_ACPI)
>>  u32 i2c_acpi_find_bus_speed(struct device *dev);
>> +struct i2c_client *i2c_acpi_new_device(struct device *dev, int
>> index);
>>  #else
>>  static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
>>  {
>>  	return 0;
>>  }
>> +static inline struct i2c_client *i2c_acpi_new_device(struct device
>> *d, int i)
>> +{
>> +	return NULL;
>> +}
>>  #endif /* CONFIG_ACPI */
>>
>>  #endif /* _LINUX_I2C_H */
>
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Patch

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 32b58fb..fd45207 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -421,6 +421,54 @@  static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
 static struct notifier_block i2c_acpi_notifier = {
 	.notifier_call = i2c_acpi_notify,
 };
+
+/**
+ * i2c_acpi_new_device - Create i2c client for the Nth acpi resource of dev
+ * @dev:     Device owning the acpi resources to get the client from
+ * @index:   Index of acpi resource to get
+ *
+ * By default the i2c subsys creates an i2c-client for the first I2cSerialBus
+ * resource of an acpi_device, but some acpi_devices have multiple
+ * I2cSerialBus resources and the driver may need access to the others.
+ * This function can be used by drivers to create an i2c-client for any
+ * resource of an acpi_device.
+ *
+ * Returns a pointer to the new i2c-client, or NULL if the resource or
+ * adapter were not found.
+ */
+struct i2c_client *i2c_acpi_new_device(struct device *dev, int index)
+{
+	struct i2c_acpi_lookup lookup;
+	struct i2c_board_info info;
+	struct i2c_adapter *adapter;
+	struct acpi_device *adev;
+	LIST_HEAD(resource_list);
+	int ret;
+
+	adev = ACPI_COMPANION(dev);
+	if (!adev)
+		return NULL;
+
+	memset(&info, 0, sizeof(info));
+	memset(&lookup, 0, sizeof(lookup));
+	lookup.info = &info;
+	lookup.device_handle = acpi_device_handle(adev);
+	lookup.index = index;
+
+	ret = acpi_dev_get_resources(adev, &resource_list,
+				     i2c_acpi_fill_info, &lookup);
+	acpi_dev_free_resource_list(&resource_list);
+
+	if (ret < 0 || !info.addr)
+		return NULL;
+
+	adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
+	if (!adapter)
+		return NULL;
+
+	return i2c_new_device(adapter, &info);
+}
+EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
 #else /* CONFIG_ACPI */
 static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
 extern struct notifier_block i2c_acpi_notifier;
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 6b18352..369ebfa 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -824,11 +824,16 @@  static inline const struct of_device_id
 
 #if IS_ENABLED(CONFIG_ACPI)
 u32 i2c_acpi_find_bus_speed(struct device *dev);
+struct i2c_client *i2c_acpi_new_device(struct device *dev, int index);
 #else
 static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
 {
 	return 0;
 }
+static inline struct i2c_client *i2c_acpi_new_device(struct device *d, int i)
+{
+	return NULL;
+}
 #endif /* CONFIG_ACPI */
 
 #endif /* _LINUX_I2C_H */