From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751480Ab2KPKEn (ORCPT ); Fri, 16 Nov 2012 05:04:43 -0500 Received: from ogre.sisk.pl ([193.178.161.156]:48284 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751148Ab2KPKEm (ORCPT ); Fri, 16 Nov 2012 05:04:42 -0500 From: "Rafael J. Wysocki" To: Mika Westerberg , khali@linux-fr.org, ben-linux@fluff.org, w.sang@pengutronix.de Cc: linux-kernel@vger.kernel.org, lenb@kernel.org, rafael.j.wysocki@intel.com, broonie@opensource.wolfsonmicro.com, grant.likely@secretlab.ca, linus.walleij@linaro.org, bhelgaas@google.com, mathias.nyman@linux.intel.com, linux-acpi@vger.kernel.org Subject: Re: [PATCH v2 3/3] i2c / ACPI: add ACPI enumeration support Date: Fri, 16 Nov 2012 11:09:03 +0100 Message-ID: <2439178.tCj2rUMYJS@vostro.rjw.lan> User-Agent: KMail/4.8.5 (Linux/3.7.0-rc5; KDE/4.8.5; x86_64; ; ) In-Reply-To: <1352977397-2280-4-git-send-email-mika.westerberg@linux.intel.com> References: <1352977397-2280-1-git-send-email-mika.westerberg@linux.intel.com> <1352977397-2280-4-git-send-email-mika.westerberg@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday, November 15, 2012 01:03:17 PM Mika Westerberg wrote: > ACPI 5 introduced I2cSerialBus resource that makes it possible to enumerate > and configure the I2C slave devices behind the I2C controller. This patch > adds helper functions to support I2C slave enumeration. > > An ACPI enabled I2C controller driver only needs to call acpi_i2c_register_devices() > in order to get its slave devices enumerated, created and bound to the > corresponding ACPI handle. > > Signed-off-by: Mika Westerberg Are there any objections against this patch or comments? Worfram? Jean? Ben? Rafael > --- > drivers/acpi/Kconfig | 6 ++ > drivers/acpi/Makefile | 1 + > drivers/acpi/acpi_i2c.c | 212 ++++++++++++++++++++++++++++++++++++++++++++++ > drivers/i2c/i2c-core.c | 10 +++ > include/linux/acpi_i2c.h | 27 ++++++ > 5 files changed, 256 insertions(+) > create mode 100644 drivers/acpi/acpi_i2c.c > create mode 100644 include/linux/acpi_i2c.h > > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig > index 119d58d..0300bf6 100644 > --- a/drivers/acpi/Kconfig > +++ b/drivers/acpi/Kconfig > @@ -181,6 +181,12 @@ config ACPI_DOCK > This driver supports ACPI-controlled docking stations and removable > drive bays such as the IBM Ultrabay and the Dell Module Bay. > > +config ACPI_I2C > + def_tristate I2C > + depends on I2C > + help > + ACPI I2C enumeration support. > + > config ACPI_PROCESSOR > tristate "Processor" > select THERMAL > diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile > index 7289828..2a4502b 100644 > --- a/drivers/acpi/Makefile > +++ b/drivers/acpi/Makefile > @@ -70,6 +70,7 @@ obj-$(CONFIG_ACPI_HED) += hed.o > obj-$(CONFIG_ACPI_EC_DEBUGFS) += ec_sys.o > obj-$(CONFIG_ACPI_CUSTOM_METHOD)+= custom_method.o > obj-$(CONFIG_ACPI_BGRT) += bgrt.o > +obj-$(CONFIG_ACPI_I2C) += acpi_i2c.o > > # processor has its own "processor." module_param namespace > processor-y := processor_driver.o processor_throttling.o > diff --git a/drivers/acpi/acpi_i2c.c b/drivers/acpi/acpi_i2c.c > new file mode 100644 > index 0000000..5bf2dad > --- /dev/null > +++ b/drivers/acpi/acpi_i2c.c > @@ -0,0 +1,212 @@ > +/* > + * ACPI I2C enumeration support > + * > + * Copyright (C) 2012, Intel Corporation > + * Author: Mika Westerberg > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > + > +ACPI_MODULE_NAME("i2c"); > + > +static int acpi_i2c_add_resource(struct acpi_resource *ares, void *data) > +{ > + struct acpi_resource_i2c_serialbus *sb; > + struct i2c_board_info *info = data; > + > + if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) > + return 0; > + > + sb = &ares->data.i2c_serial_bus; > + if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C) > + return 0; > + > + info->addr = sb->slave_address; > + if (sb->access_mode == ACPI_I2C_10BIT_MODE) > + info->flags |= I2C_CLIENT_TEN; > + > + return 1; > +} > + > +static acpi_status acpi_i2c_add_device(acpi_handle handle, u32 level, > + void *data, void **return_value) > +{ > + struct i2c_adapter *adapter = data; > + struct resource_list_entry *rentry; > + struct list_head resource_list; > + struct i2c_board_info info; > + struct acpi_device *adev; > + int ret; > + > + if (acpi_bus_get_device(handle, &adev)) > + return AE_OK; > + if (acpi_bus_get_status(adev) || !adev->status.present) > + return AE_OK; > + > + memset(&info, 0, sizeof(info)); > + > + INIT_LIST_HEAD(&resource_list); > + ret = acpi_dev_get_resources(adev, &resource_list, > + acpi_i2c_add_resource, &info); > + if (ret < 0) > + return AE_OK; > + > + list_for_each_entry(rentry, &resource_list, node) { > + struct resource *r = &rentry->res; > + > + if (resource_type(r) == IORESOURCE_IRQ) { > + info.irq = r->start; > + break; > + } > + } > + > + acpi_dev_free_resource_list(&resource_list); > + > + if (!info.addr) > + return AE_OK; > + > + strlcpy(info.type, dev_name(&adev->dev), sizeof(info.type)); > + if (!i2c_new_device(adapter, &info)) { > + dev_err(&adapter->dev, > + "failed to add I2C device %s from ACPI\n", > + dev_name(&adev->dev)); > + } > + > + return AE_OK; > +} > + > +/** > + * acpi_i2c_register_devices - enumerate I2C slave devices behind adapter > + * @adapter: pointer to adapter > + * > + * Enumerate all I2C slave devices behind this adapter by walking the ACPI > + * namespace. When a device is found it will be added to the Linux device > + * model and bound to the corresponding ACPI handle. > + */ > +void acpi_i2c_register_devices(struct i2c_adapter *adapter) > +{ > + acpi_handle handle; > + acpi_status status; > + > + handle = adapter->dev.acpi_handle; > + if (!handle) > + return; > + > + status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, > + acpi_i2c_add_device, NULL, > + adapter, NULL); > + if (ACPI_FAILURE(status)) > + dev_warn(&adapter->dev, "failed to enumerate I2C slaves\n"); > +} > +EXPORT_SYMBOL_GPL(acpi_i2c_register_devices); > + > +struct acpi_i2c_find { > + acpi_handle handle; > + u16 addr; > + bool found; > +}; > + > +static int acpi_i2c_find_child_address(struct acpi_resource *ares, void *data) > +{ > + struct acpi_resource_i2c_serialbus *sb; > + struct acpi_i2c_find *i2c_find = data; > + > + if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) > + return 1; > + > + sb = &ares->data.i2c_serial_bus; > + if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C) > + return 1; > + > + if (sb->slave_address == i2c_find->addr) > + i2c_find->found = true; > + > + return 1; > +} > + > +static acpi_status acpi_i2c_find_child(acpi_handle handle, u32 level, > + void *data, void **return_value) > +{ > + struct acpi_i2c_find *i2c_find = data; > + struct list_head resource_list; > + struct acpi_device *adev; > + int ret; > + > + if (acpi_bus_get_device(handle, &adev)) > + return AE_OK; > + if (acpi_bus_get_status(adev) || !adev->status.present) > + return AE_OK; > + > + INIT_LIST_HEAD(&resource_list); > + ret = acpi_dev_get_resources(adev, &resource_list, > + acpi_i2c_find_child_address, i2c_find); > + if (ret < 0) > + return AE_OK; > + > + acpi_dev_free_resource_list(&resource_list); > + > + if (i2c_find->found) { > + i2c_find->handle = handle; > + return AE_CTRL_TERMINATE; > + } > + return AE_OK; > +} > + > +static int acpi_i2c_find_device(struct device *dev, acpi_handle *handle) > +{ > + struct acpi_i2c_find i2c_find; > + struct i2c_adapter *adapter; > + struct i2c_client *client; > + acpi_handle parent; > + acpi_status status; > + > + client = i2c_verify_client(dev); > + if (!client) > + return -ENODEV; > + > + adapter = client->adapter; > + if (!adapter) > + return -ENODEV; > + > + parent = adapter->dev.acpi_handle; > + if (!parent) > + return -ENODEV; > + > + memset(&i2c_find, 0, sizeof(i2c_find)); > + i2c_find.addr = client->addr; > + > + status = acpi_walk_namespace(ACPI_TYPE_DEVICE, parent, 1, > + acpi_i2c_find_child, NULL, > + &i2c_find, NULL); > + if (ACPI_FAILURE(status) || !i2c_find.handle) > + return -ENODEV; > + > + *handle = i2c_find.handle; > + return 0; > +} > + > +static struct acpi_bus_type acpi_i2c_bus = { > + .bus = &i2c_bus_type, > + .find_device = acpi_i2c_find_device, > +}; > + > +void acpi_i2c_bus_register(void) > +{ > + register_acpi_bus_type(&acpi_i2c_bus); > +} > +EXPORT_SYMBOL_GPL(acpi_i2c_bus_register); > + > +void acpi_i2c_bus_unregister(void) > +{ > + unregister_acpi_bus_type(&acpi_i2c_bus); > +} > +EXPORT_SYMBOL_GPL(acpi_i2c_bus_unregister); > diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c > index a7edf98..7385de2f 100644 > --- a/drivers/i2c/i2c-core.c > +++ b/drivers/i2c/i2c-core.c > @@ -39,6 +39,8 @@ > #include > #include > #include > +#include > +#include > #include > > #include "i2c-core.h" > @@ -78,6 +80,10 @@ static int i2c_device_match(struct device *dev, struct device_driver *drv) > if (of_driver_match_device(dev, drv)) > return 1; > > + /* Then ACPI style match */ > + if (acpi_driver_match_device(dev, drv)) > + return 1; > + > driver = to_i2c_driver(drv); > /* match on an id table if there is one */ > if (driver->id_table) > @@ -1298,6 +1304,8 @@ static int __init i2c_init(void) > retval = i2c_add_driver(&dummy_driver); > if (retval) > goto class_err; > + > + acpi_i2c_bus_register(); > return 0; > > class_err: > @@ -1311,6 +1319,8 @@ bus_err: > > static void __exit i2c_exit(void) > { > + acpi_i2c_bus_unregister(); > + > i2c_del_driver(&dummy_driver); > #ifdef CONFIG_I2C_COMPAT > class_compat_unregister(i2c_adapter_compat_class); > diff --git a/include/linux/acpi_i2c.h b/include/linux/acpi_i2c.h > new file mode 100644 > index 0000000..cf2233f > --- /dev/null > +++ b/include/linux/acpi_i2c.h > @@ -0,0 +1,27 @@ > +/* > + * ACPI I2C enumeration support > + * > + * Copyright (C) 2012, Intel Corporation > + * Author: Mika Westerberg > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + */ > + > +#ifndef LINUX_ACPI_I2C_H > +#define LINUX_ACPI_I2C_H > + > +struct i2c_adapter; > + > +#if IS_ENABLED(CONFIG_ACPI_I2C) > +extern void acpi_i2c_register_devices(struct i2c_adapter *adap); > +extern void acpi_i2c_bus_register(void); > +extern void acpi_i2c_bus_unregister(void); > +#else > +static inline void acpi_i2c_register_devices(struct i2c_adapter *adap) {} > +static inline void acpi_i2c_bus_register(void) {} > +static inline void acpi_i2c_bus_unregister(void) {} > +#endif /* IS_ENABLED(CONFIG_ACPI_I2C) */ > + > +#endif /* LINUX_ACPI_I2C_H */ > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.