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

Hans de Goede
2017-03-22T15:59:17Z

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 */
>