diff options
Diffstat (limited to 'drivers/i2c/i2c-core.c')
| -rw-r--r-- | drivers/i2c/i2c-core.c | 206 |
1 files changed, 202 insertions, 4 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index f32ca293ae0..29d3f045a2b 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -23,7 +23,11 @@ SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and Jean Delvare <khali@linux-fr.org> Mux support by Rodolfo Giometti <giometti@enneenne.com> and - Michael Lawnick <michael.lawnick.ext@nsn.com> */ + Michael Lawnick <michael.lawnick.ext@nsn.com> + OF support is copyright (c) 2008 Jochen Friedrich <jochen@scram.de> + (based on a previous patch from Jon Smirl <jonsmirl@gmail.com>) and + (c) 2013 Wolfram Sang <wsa@the-dreams.de> + */ #include <linux/module.h> #include <linux/kernel.h> @@ -35,7 +39,9 @@ #include <linux/init.h> #include <linux/idr.h> #include <linux/mutex.h> +#include <linux/of.h> #include <linux/of_device.h> +#include <linux/of_irq.h> #include <linux/completion.h> #include <linux/hardirq.h> #include <linux/irqflags.h> @@ -954,6 +960,194 @@ static void i2c_scan_static_board_info(struct i2c_adapter *adapter) up_read(&__i2c_board_lock); } +/* OF support code */ + +#if IS_ENABLED(CONFIG_OF) +static void of_i2c_register_devices(struct i2c_adapter *adap) +{ + void *result; + struct device_node *node; + + /* Only register child devices if the adapter has a node pointer set */ + if (!adap->dev.of_node) + return; + + dev_dbg(&adap->dev, "of_i2c: walking child nodes\n"); + + for_each_available_child_of_node(adap->dev.of_node, node) { + struct i2c_board_info info = {}; + struct dev_archdata dev_ad = {}; + const __be32 *addr; + int len; + + dev_dbg(&adap->dev, "of_i2c: register %s\n", node->full_name); + + if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) { + dev_err(&adap->dev, "of_i2c: modalias failure on %s\n", + node->full_name); + continue; + } + + addr = of_get_property(node, "reg", &len); + if (!addr || (len < sizeof(int))) { + dev_err(&adap->dev, "of_i2c: invalid reg on %s\n", + node->full_name); + continue; + } + + info.addr = be32_to_cpup(addr); + if (info.addr > (1 << 10) - 1) { + dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n", + info.addr, node->full_name); + continue; + } + + info.irq = irq_of_parse_and_map(node, 0); + info.of_node = of_node_get(node); + info.archdata = &dev_ad; + + if (of_get_property(node, "wakeup-source", NULL)) + info.flags |= I2C_CLIENT_WAKE; + + request_module("%s%s", I2C_MODULE_PREFIX, info.type); + + result = i2c_new_device(adap, &info); + if (result == NULL) { + dev_err(&adap->dev, "of_i2c: Failure registering %s\n", + node->full_name); + of_node_put(node); + irq_dispose_mapping(info.irq); + continue; + } + } +} + +static int of_dev_node_match(struct device *dev, void *data) +{ + return dev->of_node == data; +} + +/* must call put_device() when done with returned i2c_client device */ +struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) +{ + struct device *dev; + + dev = bus_find_device(&i2c_bus_type, NULL, node, + of_dev_node_match); + if (!dev) + return NULL; + + return i2c_verify_client(dev); +} +EXPORT_SYMBOL(of_find_i2c_device_by_node); + +/* must call put_device() when done with returned i2c_adapter device */ +struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) +{ + struct device *dev; + + dev = bus_find_device(&i2c_bus_type, NULL, node, + of_dev_node_match); + if (!dev) + return NULL; + + return i2c_verify_adapter(dev); +} +EXPORT_SYMBOL(of_find_i2c_adapter_by_node); +#else +static void of_i2c_register_devices(struct i2c_adapter *adap) { } +#endif /* CONFIG_OF */ + +/* ACPI support code */ + +#if IS_ENABLED(CONFIG_ACPI) +static int acpi_i2c_add_resource(struct acpi_resource *ares, void *data) +{ + struct i2c_board_info *info = data; + + if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { + struct acpi_resource_i2c_serialbus *sb; + + sb = &ares->data.i2c_serial_bus; + if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_I2C) { + info->addr = sb->slave_address; + if (sb->access_mode == ACPI_I2C_10BIT_MODE) + info->flags |= I2C_CLIENT_TEN; + } + } else if (info->irq < 0) { + struct resource r; + + if (acpi_dev_resource_interrupt(ares, 0, &r)) + info->irq = r.start; + } + + /* Tell the ACPI core to skip this resource */ + 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 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)); + info.acpi_node.handle = handle; + info.irq = -1; + + INIT_LIST_HEAD(&resource_list); + ret = acpi_dev_get_resources(adev, &resource_list, + acpi_i2c_add_resource, &info); + acpi_dev_free_resource_list(&resource_list); + + if (ret < 0 || !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 + * @adap: 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. + */ +static void acpi_i2c_register_devices(struct i2c_adapter *adap) +{ + acpi_handle handle; + acpi_status status; + + handle = ACPI_HANDLE(adap->dev.parent); + if (!handle) + return; + + status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, + acpi_i2c_add_device, NULL, + adap, NULL); + if (ACPI_FAILURE(status)) + dev_warn(&adap->dev, "failed to enumerate I2C slaves\n"); +} +#else +static inline void acpi_i2c_register_devices(struct i2c_adapter *adap) {} +#endif /* CONFIG_ACPI */ + static int i2c_do_add_adapter(struct i2c_driver *driver, struct i2c_adapter *adap) { @@ -1058,6 +1252,9 @@ static int i2c_register_adapter(struct i2c_adapter *adap) exit_recovery: /* create pre-declared device nodes */ + of_i2c_register_devices(adap); + acpi_i2c_register_devices(adap); + if (adap->nr < __i2c_first_dynamic_bus_num) i2c_scan_static_board_info(adap); @@ -1282,7 +1479,6 @@ void i2c_del_adapter(struct i2c_adapter *adap) } EXPORT_SYMBOL(i2c_del_adapter); - /* ------------------------------------------------------------------------- */ int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)) @@ -1665,7 +1861,8 @@ static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &dummy); else { - dev_warn(&adap->dev, "No suitable probing method supported\n"); + dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n", + addr); err = -EOPNOTSUPP; } @@ -1825,7 +2022,8 @@ EXPORT_SYMBOL(i2c_get_adapter); void i2c_put_adapter(struct i2c_adapter *adap) { - module_put(adap->owner); + if (adap) + module_put(adap->owner); } EXPORT_SYMBOL(i2c_put_adapter); |