1 files changed, 317 insertions, 29 deletions

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 48e31ed69db..7c7f4b856ba 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -21,9 +21,13 @@
 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>.
    All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl>
    SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and
-   Jean Delvare <khali@linux-fr.org>
+   Jean Delvare <jdelvare@suse.de>
    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>
@@ -35,17 +39,22 @@
 #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>
 #include <linux/rwsem.h>
 #include <linux/pm_runtime.h>
 #include <linux/acpi.h>
+#include <linux/jump_label.h>
 #include <asm/uaccess.h>
 
 #include "i2c-core.h"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/i2c.h>
 
 /* core_lock protects i2c_adapter_idr, and guarantees
    that device detection, deletion of detected devices, and attach_adapter
@@ -56,6 +65,18 @@ static DEFINE_IDR(i2c_adapter_idr);
 static struct device_type i2c_client_type;
 static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
 
+static struct static_key i2c_trace_msg = STATIC_KEY_INIT_FALSE;
+
+void i2c_transfer_trace_reg(void)
+{
+	static_key_slow_inc(&i2c_trace_msg);
+}
+
+void i2c_transfer_trace_unreg(void)
+{
+	static_key_slow_dec(&i2c_trace_msg);
+}
+
 /* ------------------------------------------------------------------------- */
 
 static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
@@ -98,6 +119,11 @@ static int i2c_device_match(struct device *dev, struct device_driver *drv)
 static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
 	struct i2c_client	*client = to_i2c_client(dev);
+	int rc;
+
+	rc = acpi_device_uevent_modalias(dev, env);
+	if (rc != -ENODEV)
+		return rc;
 
 	if (add_uevent_var(env, "MODALIAS=%s%s",
 			   I2C_MODULE_PREFIX, client->name))
@@ -242,17 +268,17 @@ static int i2c_device_probe(struct device *dev)
 	driver = to_i2c_driver(dev->driver);
 	if (!driver->probe || !driver->id_table)
 		return -ENODEV;
-	client->driver = driver;
+
 	if (!device_can_wakeup(&client->dev))
 		device_init_wakeup(&client->dev,
 					client->flags & I2C_CLIENT_WAKE);
 	dev_dbg(dev, "probe\n");
 
+	acpi_dev_pm_attach(&client->dev, true);
 	status = driver->probe(client, i2c_match_id(driver->id_table, client));
-	if (status) {
-		client->driver = NULL;
-		i2c_set_clientdata(client, NULL);
-	}
+	if (status)
+		acpi_dev_pm_detach(&client->dev, true);
+
 	return status;
 }
 
@@ -260,7 +286,7 @@ static int i2c_device_remove(struct device *dev)
 {
 	struct i2c_client	*client = i2c_verify_client(dev);
 	struct i2c_driver	*driver;
-	int			status;
+	int status = 0;
 
 	if (!client || !dev->driver)
 		return 0;
@@ -269,14 +295,9 @@ static int i2c_device_remove(struct device *dev)
 	if (driver->remove) {
 		dev_dbg(dev, "remove\n");
 		status = driver->remove(client);
-	} else {
-		dev->driver = NULL;
-		status = 0;
-	}
-	if (status == 0) {
-		client->driver = NULL;
-		i2c_set_clientdata(client, NULL);
 	}
+
+	acpi_dev_pm_detach(&client->dev, true);
 	return status;
 }
 
@@ -403,6 +424,12 @@ static ssize_t
 show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct i2c_client *client = to_i2c_client(dev);
+	int len;
+
+	len = acpi_device_modalias(dev, buf, PAGE_SIZE -1);
+	if (len != -ENODEV)
+		return len;
+
 	return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
 }
 
@@ -435,7 +462,7 @@ static const struct dev_pm_ops i2c_device_pm_ops = {
 	SET_RUNTIME_PM_OPS(
 		pm_generic_runtime_suspend,
 		pm_generic_runtime_resume,
-		pm_generic_runtime_idle
+		NULL
 	)
 };
 
@@ -609,6 +636,22 @@ void i2c_unlock_adapter(struct i2c_adapter *adapter)
 }
 EXPORT_SYMBOL_GPL(i2c_unlock_adapter);
 
+static void i2c_dev_set_name(struct i2c_adapter *adap,
+			     struct i2c_client *client)
+{
+	struct acpi_device *adev = ACPI_COMPANION(&client->dev);
+
+	if (adev) {
+		dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev));
+		return;
+	}
+
+	/* For 10-bit clients, add an arbitrary offset to avoid collisions */
+	dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
+		     client->addr | ((client->flags & I2C_CLIENT_TEN)
+				     ? 0xa000 : 0));
+}
+
 /**
  * i2c_new_device - instantiate an i2c device
  * @adap: the adapter managing the device
@@ -665,12 +708,9 @@ i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
 	client->dev.bus = &i2c_bus_type;
 	client->dev.type = &i2c_client_type;
 	client->dev.of_node = info->of_node;
-	ACPI_HANDLE_SET(&client->dev, info->acpi_node.handle);
+	ACPI_COMPANION_SET(&client->dev, info->acpi_node.companion);
 
-	/* For 10-bit clients, add an arbitrary offset to avoid collisions */
-	dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
-		     client->addr | ((client->flags & I2C_CLIENT_TEN)
-				     ? 0xa000 : 0));
+	i2c_dev_set_name(adap, client);
 	status = device_register(&client->dev);
 	if (status)
 		goto out_err;
@@ -954,6 +994,199 @@ 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.companion = adev;
+	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;
+
+	adev->power.flags.ignore_parent = true;
+	strlcpy(info.type, dev_name(&adev->dev), sizeof(info.type));
+	if (!i2c_new_device(adapter, &info)) {
+		adev->power.flags.ignore_parent = false;
+		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;
+
+	if (!adap->dev.parent)
+		return;
+
+	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 +1291,9 @@ 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 +1518,6 @@ 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 *))
@@ -1410,9 +1645,14 @@ static int i2c_cmd(struct device *dev, void *_arg)
 {
 	struct i2c_client	*client = i2c_verify_client(dev);
 	struct i2c_cmd_arg	*arg = _arg;
+	struct i2c_driver	*driver;
 
-	if (client && client->driver && client->driver->command)
-		client->driver->command(client, arg->cmd, arg->arg);
+	if (!client || !client->dev.driver)
+		return 0;
+
+	driver = to_i2c_driver(client->dev.driver);
+	if (driver->command)
+		driver->command(client, arg->cmd, arg->arg);
 	return 0;
 }
 
@@ -1461,6 +1701,7 @@ static void __exit i2c_exit(void)
 	class_compat_unregister(i2c_adapter_compat_class);
 #endif
 	bus_unregister(&i2c_bus_type);
+	tracepoint_synchronize_unregister();
 }
 
 /* We must initialize early, because some subsystems register i2c drivers
@@ -1491,6 +1732,19 @@ int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 	unsigned long orig_jiffies;
 	int ret, try;
 
+	/* i2c_trace_msg gets enabled when tracepoint i2c_transfer gets
+	 * enabled.  This is an efficient way of keeping the for-loop from
+	 * being executed when not needed.
+	 */
+	if (static_key_false(&i2c_trace_msg)) {
+		int i;
+		for (i = 0; i < num; i++)
+			if (msgs[i].flags & I2C_M_RD)
+				trace_i2c_read(adap, &msgs[i], i);
+			else
+				trace_i2c_write(adap, &msgs[i], i);
+	}
+
 	/* Retry automatically on arbitration loss */
 	orig_jiffies = jiffies;
 	for (ret = 0, try = 0; try <= adap->retries; try++) {
@@ -1501,6 +1755,14 @@ int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 			break;
 	}
 
+	if (static_key_false(&i2c_trace_msg)) {
+		int i;
+		for (i = 0; i < ret; i++)
+			if (msgs[i].flags & I2C_M_RD)
+				trace_i2c_reply(adap, &msgs[i], i);
+		trace_i2c_result(adap, i, ret);
+	}
+
 	return ret;
 }
 EXPORT_SYMBOL(__i2c_transfer);
@@ -1665,7 +1927,8 @@ 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;
 	}
 
@@ -1715,6 +1978,13 @@ static int i2c_detect_address(struct i2c_client *temp_client,
 		struct i2c_client *client;
 
 		/* Detection succeeded, instantiate the device */
+		if (adapter->class & I2C_CLASS_DEPRECATED)
+			dev_warn(&adapter->dev,
+				"This adapter will soon drop class based instantiation of devices. "
+				"Please make sure client 0x%02x gets instantiated by other means. "
+				"Check 'Documentation/i2c/instantiating-devices' for details.\n",
+				info.addr);
+
 		dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n",
 			info.type, info.addr);
 		client = i2c_new_device(adapter, &info);
@@ -1825,7 +2095,8 @@ 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);
 
@@ -2294,6 +2565,14 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags,
 	int try;
 	s32 res;
 
+	/* If enabled, the following two tracepoints are conditional on
+	 * read_write and protocol.
+	 */
+	trace_smbus_write(adapter, addr, flags, read_write,
+			  command, protocol, data);
+	trace_smbus_read(adapter, addr, flags, read_write,
+			 command, protocol);
+
 	flags &= I2C_M_TEN | I2C_CLIENT_PEC | I2C_CLIENT_SCCB;
 
 	if (adapter->algo->smbus_xfer) {
@@ -2314,15 +2593,24 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags,
 		i2c_unlock_adapter(adapter);
 
 		if (res != -EOPNOTSUPP || !adapter->algo->master_xfer)
-			return res;
+			goto trace;
 		/*
 		 * Fall back to i2c_smbus_xfer_emulated if the adapter doesn't
 		 * implement native support for the SMBus operation.
 		 */
 	}
 
-	return i2c_smbus_xfer_emulated(adapter, addr, flags, read_write,
-				       command, protocol, data);
+	res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write,
+				      command, protocol, data);
+
+trace:
+	/* If enabled, the reply tracepoint is conditional on read_write. */
+	trace_smbus_reply(adapter, addr, flags, read_write,
+			  command, protocol, data);
+	trace_smbus_result(adapter, addr, flags, read_write,
+			   command, protocol, res);
+
+	return res;
 }
 EXPORT_SYMBOL(i2c_smbus_xfer);