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path: root/drivers/i2c/i2c-core.c
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Diffstat (limited to 'drivers/i2c/i2c-core.c')
-rw-r--r--drivers/i2c/i2c-core.c206
1 files changed, 202 insertions, 4 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index f32ca293ae0e..29d3f045a2bf 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);