From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans de Goede Subject: [PATCH 2/3] i2c: core: Add new i2c_acpi_new_device helper function Date: Fri, 10 Mar 2017 22:16:06 +0100 Message-ID: <20170310211607.16998-2-hdegoede@redhat.com> References: <20170310211607.16998-1-hdegoede@redhat.com> Return-path: Received: from mx1.redhat.com ([209.132.183.28]:34804 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754391AbdCJVQO (ORCPT ); Fri, 10 Mar 2017 16:16:14 -0500 In-Reply-To: <20170310211607.16998-1-hdegoede@redhat.com> Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: Wolfram Sang Cc: linux-i2c@vger.kernel.org, Hans de Goede 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 --- 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..8ddd55b 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 */ -- 2.9.3