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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.c272
1 files changed, 183 insertions, 89 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index da3a02ef4a31..98fffa3a09f7 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -88,7 +88,7 @@ void i2c_transfer_trace_unreg(void)
}
#if defined(CONFIG_ACPI)
-struct acpi_i2c_handler_data {
+struct i2c_acpi_handler_data {
struct acpi_connection_info info;
struct i2c_adapter *adapter;
};
@@ -103,15 +103,18 @@ struct gsb_buffer {
};
} __packed;
-struct acpi_i2c_lookup {
+struct i2c_acpi_lookup {
struct i2c_board_info *info;
acpi_handle adapter_handle;
acpi_handle device_handle;
+ acpi_handle search_handle;
+ u32 speed;
+ u32 min_speed;
};
-static int acpi_i2c_fill_info(struct acpi_resource *ares, void *data)
+static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data)
{
- struct acpi_i2c_lookup *lookup = data;
+ struct i2c_acpi_lookup *lookup = data;
struct i2c_board_info *info = lookup->info;
struct acpi_resource_i2c_serialbus *sb;
acpi_status status;
@@ -130,19 +133,18 @@ static int acpi_i2c_fill_info(struct acpi_resource *ares, void *data)
return 1;
info->addr = sb->slave_address;
+ lookup->speed = sb->connection_speed;
if (sb->access_mode == ACPI_I2C_10BIT_MODE)
info->flags |= I2C_CLIENT_TEN;
return 1;
}
-static int acpi_i2c_get_info(struct acpi_device *adev,
- struct i2c_board_info *info,
- acpi_handle *adapter_handle)
+static int i2c_acpi_do_lookup(struct acpi_device *adev,
+ struct i2c_acpi_lookup *lookup)
{
+ struct i2c_board_info *info = lookup->info;
struct list_head resource_list;
- struct resource_entry *entry;
- struct acpi_i2c_lookup lookup;
int ret;
if (acpi_bus_get_status(adev) || !adev->status.present ||
@@ -150,24 +152,58 @@ static int acpi_i2c_get_info(struct acpi_device *adev,
return -EINVAL;
memset(info, 0, sizeof(*info));
- info->fwnode = acpi_fwnode_handle(adev);
-
- memset(&lookup, 0, sizeof(lookup));
- lookup.device_handle = acpi_device_handle(adev);
- lookup.info = info;
+ lookup->device_handle = acpi_device_handle(adev);
/* Look up for I2cSerialBus resource */
INIT_LIST_HEAD(&resource_list);
ret = acpi_dev_get_resources(adev, &resource_list,
- acpi_i2c_fill_info, &lookup);
+ i2c_acpi_fill_info, lookup);
acpi_dev_free_resource_list(&resource_list);
if (ret < 0 || !info->addr)
return -EINVAL;
- *adapter_handle = lookup.adapter_handle;
+ return 0;
+}
+
+static int i2c_acpi_get_info(struct acpi_device *adev,
+ struct i2c_board_info *info,
+ struct i2c_adapter *adapter,
+ acpi_handle *adapter_handle)
+{
+ struct list_head resource_list;
+ struct resource_entry *entry;
+ struct i2c_acpi_lookup lookup;
+ int ret;
+
+ memset(&lookup, 0, sizeof(lookup));
+ lookup.info = info;
+
+ ret = i2c_acpi_do_lookup(adev, &lookup);
+ if (ret)
+ return ret;
+
+ if (adapter) {
+ /* The adapter must match the one in I2cSerialBus() connector */
+ if (ACPI_HANDLE(&adapter->dev) != lookup.adapter_handle)
+ return -ENODEV;
+ } else {
+ struct acpi_device *adapter_adev;
+
+ /* The adapter must be present */
+ if (acpi_bus_get_device(lookup.adapter_handle, &adapter_adev))
+ return -ENODEV;
+ if (acpi_bus_get_status(adapter_adev) ||
+ !adapter_adev->status.present)
+ return -ENODEV;
+ }
+
+ info->fwnode = acpi_fwnode_handle(adev);
+ if (adapter_handle)
+ *adapter_handle = lookup.adapter_handle;
/* Then fill IRQ number if any */
+ INIT_LIST_HEAD(&resource_list);
ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
if (ret < 0)
return -EINVAL;
@@ -186,7 +222,7 @@ static int acpi_i2c_get_info(struct acpi_device *adev,
return 0;
}
-static void acpi_i2c_register_device(struct i2c_adapter *adapter,
+static void i2c_acpi_register_device(struct i2c_adapter *adapter,
struct acpi_device *adev,
struct i2c_board_info *info)
{
@@ -201,39 +237,35 @@ static void acpi_i2c_register_device(struct i2c_adapter *adapter,
}
}
-static acpi_status acpi_i2c_add_device(acpi_handle handle, u32 level,
+static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level,
void *data, void **return_value)
{
struct i2c_adapter *adapter = data;
struct acpi_device *adev;
- acpi_handle adapter_handle;
struct i2c_board_info info;
if (acpi_bus_get_device(handle, &adev))
return AE_OK;
- if (acpi_i2c_get_info(adev, &info, &adapter_handle))
+ if (i2c_acpi_get_info(adev, &info, adapter, NULL))
return AE_OK;
- if (adapter_handle != ACPI_HANDLE(&adapter->dev))
- return AE_OK;
-
- acpi_i2c_register_device(adapter, adev, &info);
+ i2c_acpi_register_device(adapter, adev, &info);
return AE_OK;
}
-#define ACPI_I2C_MAX_SCAN_DEPTH 32
+#define I2C_ACPI_MAX_SCAN_DEPTH 32
/**
- * acpi_i2c_register_devices - enumerate I2C slave devices behind adapter
+ * i2c_acpi_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)
+static void i2c_acpi_register_devices(struct i2c_adapter *adap)
{
acpi_status status;
@@ -241,14 +273,72 @@ static void acpi_i2c_register_devices(struct i2c_adapter *adap)
return;
status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
- ACPI_I2C_MAX_SCAN_DEPTH,
- acpi_i2c_add_device, NULL,
+ I2C_ACPI_MAX_SCAN_DEPTH,
+ i2c_acpi_add_device, NULL,
adap, NULL);
if (ACPI_FAILURE(status))
dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
}
-static int acpi_i2c_match_adapter(struct device *dev, void *data)
+static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
+ void *data, void **return_value)
+{
+ struct i2c_acpi_lookup *lookup = data;
+ struct acpi_device *adev;
+
+ if (acpi_bus_get_device(handle, &adev))
+ return AE_OK;
+
+ if (i2c_acpi_do_lookup(adev, lookup))
+ return AE_OK;
+
+ if (lookup->search_handle != lookup->adapter_handle)
+ return AE_OK;
+
+ if (lookup->speed <= lookup->min_speed)
+ lookup->min_speed = lookup->speed;
+
+ return AE_OK;
+}
+
+/**
+ * i2c_acpi_find_bus_speed - find I2C bus speed from ACPI
+ * @dev: The device owning the bus
+ *
+ * Find the I2C bus speed by walking the ACPI namespace for all I2C slaves
+ * devices connected to this bus and use the speed of slowest device.
+ *
+ * Returns the speed in Hz or zero
+ */
+u32 i2c_acpi_find_bus_speed(struct device *dev)
+{
+ struct i2c_acpi_lookup lookup;
+ struct i2c_board_info dummy;
+ acpi_status status;
+
+ if (!has_acpi_companion(dev))
+ return 0;
+
+ memset(&lookup, 0, sizeof(lookup));
+ lookup.search_handle = ACPI_HANDLE(dev);
+ lookup.min_speed = UINT_MAX;
+ lookup.info = &dummy;
+
+ status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+ I2C_ACPI_MAX_SCAN_DEPTH,
+ i2c_acpi_lookup_speed, NULL,
+ &lookup, NULL);
+
+ if (ACPI_FAILURE(status)) {
+ dev_warn(dev, "unable to find I2C bus speed from ACPI\n");
+ return 0;
+ }
+
+ return lookup.min_speed != UINT_MAX ? lookup.min_speed : 0;
+}
+EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);
+
+static int i2c_acpi_match_adapter(struct device *dev, void *data)
{
struct i2c_adapter *adapter = i2c_verify_adapter(dev);
@@ -258,29 +348,29 @@ static int acpi_i2c_match_adapter(struct device *dev, void *data)
return ACPI_HANDLE(dev) == (acpi_handle)data;
}
-static int acpi_i2c_match_device(struct device *dev, void *data)
+static int i2c_acpi_match_device(struct device *dev, void *data)
{
return ACPI_COMPANION(dev) == data;
}
-static struct i2c_adapter *acpi_i2c_find_adapter_by_handle(acpi_handle handle)
+static struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
{
struct device *dev;
dev = bus_find_device(&i2c_bus_type, NULL, handle,
- acpi_i2c_match_adapter);
+ i2c_acpi_match_adapter);
return dev ? i2c_verify_adapter(dev) : NULL;
}
-static struct i2c_client *acpi_i2c_find_client_by_adev(struct acpi_device *adev)
+static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
{
struct device *dev;
- dev = bus_find_device(&i2c_bus_type, NULL, adev, acpi_i2c_match_device);
+ dev = bus_find_device(&i2c_bus_type, NULL, adev, i2c_acpi_match_device);
return dev ? i2c_verify_client(dev) : NULL;
}
-static int acpi_i2c_notify(struct notifier_block *nb, unsigned long value,
+static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
void *arg)
{
struct acpi_device *adev = arg;
@@ -291,20 +381,20 @@ static int acpi_i2c_notify(struct notifier_block *nb, unsigned long value,
switch (value) {
case ACPI_RECONFIG_DEVICE_ADD:
- if (acpi_i2c_get_info(adev, &info, &adapter_handle))
+ if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle))
break;
- adapter = acpi_i2c_find_adapter_by_handle(adapter_handle);
+ adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);
if (!adapter)
break;
- acpi_i2c_register_device(adapter, adev, &info);
+ i2c_acpi_register_device(adapter, adev, &info);
break;
case ACPI_RECONFIG_DEVICE_REMOVE:
if (!acpi_device_enumerated(adev))
break;
- client = acpi_i2c_find_client_by_adev(adev);
+ client = i2c_acpi_find_client_by_adev(adev);
if (!client)
break;
@@ -317,10 +407,10 @@ static int acpi_i2c_notify(struct notifier_block *nb, unsigned long value,
}
static struct notifier_block i2c_acpi_notifier = {
- .notifier_call = acpi_i2c_notify,
+ .notifier_call = i2c_acpi_notify,
};
#else /* CONFIG_ACPI */
-static inline void acpi_i2c_register_devices(struct i2c_adapter *adap) { }
+static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
extern struct notifier_block i2c_acpi_notifier;
#endif /* CONFIG_ACPI */
@@ -386,12 +476,12 @@ static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
}
static acpi_status
-acpi_i2c_space_handler(u32 function, acpi_physical_address command,
+i2c_acpi_space_handler(u32 function, acpi_physical_address command,
u32 bits, u64 *value64,
void *handler_context, void *region_context)
{
struct gsb_buffer *gsb = (struct gsb_buffer *)value64;
- struct acpi_i2c_handler_data *data = handler_context;
+ struct i2c_acpi_handler_data *data = handler_context;
struct acpi_connection_info *info = &data->info;
struct acpi_resource_i2c_serialbus *sb;
struct i2c_adapter *adapter = data->adapter;
@@ -510,10 +600,10 @@ acpi_i2c_space_handler(u32 function, acpi_physical_address command,
}
-static int acpi_i2c_install_space_handler(struct i2c_adapter *adapter)
+static int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
{
acpi_handle handle;
- struct acpi_i2c_handler_data *data;
+ struct i2c_acpi_handler_data *data;
acpi_status status;
if (!adapter->dev.parent)
@@ -524,7 +614,7 @@ static int acpi_i2c_install_space_handler(struct i2c_adapter *adapter)
if (!handle)
return -ENODEV;
- data = kzalloc(sizeof(struct acpi_i2c_handler_data),
+ data = kzalloc(sizeof(struct i2c_acpi_handler_data),
GFP_KERNEL);
if (!data)
return -ENOMEM;
@@ -538,7 +628,7 @@ static int acpi_i2c_install_space_handler(struct i2c_adapter *adapter)
status = acpi_install_address_space_handler(handle,
ACPI_ADR_SPACE_GSBUS,
- &acpi_i2c_space_handler,
+ &i2c_acpi_space_handler,
NULL,
data);
if (ACPI_FAILURE(status)) {
@@ -552,10 +642,10 @@ static int acpi_i2c_install_space_handler(struct i2c_adapter *adapter)
return 0;
}
-static void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter)
+static void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
{
acpi_handle handle;
- struct acpi_i2c_handler_data *data;
+ struct i2c_acpi_handler_data *data;
acpi_status status;
if (!adapter->dev.parent)
@@ -568,7 +658,7 @@ static void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter)
acpi_remove_address_space_handler(handle,
ACPI_ADR_SPACE_GSBUS,
- &acpi_i2c_space_handler);
+ &i2c_acpi_space_handler);
status = acpi_bus_get_private_data(handle, (void **)&data);
if (ACPI_SUCCESS(status))
@@ -577,10 +667,10 @@ static void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter)
acpi_bus_detach_private_data(handle);
}
#else /* CONFIG_ACPI_I2C_OPREGION */
-static inline void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter)
+static inline void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
{ }
-static inline int acpi_i2c_install_space_handler(struct i2c_adapter *adapter)
+static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
{ return 0; }
#endif /* CONFIG_ACPI_I2C_OPREGION */
@@ -853,7 +943,7 @@ static int i2c_device_probe(struct device *dev)
status = 0;
if (status)
- dev_warn(&client->dev, "failed to set up wakeup irq");
+ dev_warn(&client->dev, "failed to set up wakeup irq\n");
}
dev_dbg(dev, "probe\n");
@@ -1208,8 +1298,9 @@ i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
return client;
out_err:
- dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x "
- "(%d)\n", client->name, client->addr, status);
+ dev_err(&adap->dev,
+ "Failed to register i2c client %s at 0x%02x (%d)\n",
+ client->name, client->addr, status);
out_err_silent:
kfree(client);
return NULL;
@@ -1335,21 +1426,19 @@ static void i2c_adapter_dev_release(struct device *dev)
complete(&adap->dev_released);
}
-/*
- * This function is only needed for mutex_lock_nested, so it is never
- * called unless locking correctness checking is enabled. Thus we
- * make it inline to avoid a compiler warning. That's what gcc ends up
- * doing anyway.
- */
-static inline unsigned int i2c_adapter_depth(struct i2c_adapter *adapter)
+unsigned int i2c_adapter_depth(struct i2c_adapter *adapter)
{
unsigned int depth = 0;
while ((adapter = i2c_parent_is_i2c_adapter(adapter)))
depth++;
+ WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES,
+ "adapter depth exceeds lockdep subclass limit\n");
+
return depth;
}
+EXPORT_SYMBOL_GPL(i2c_adapter_depth);
/*
* Let users instantiate I2C devices through sysfs. This can be used when
@@ -1678,8 +1767,8 @@ static int i2c_do_add_adapter(struct i2c_driver *driver,
if (driver->attach_adapter) {
dev_warn(&adap->dev, "%s: attach_adapter method is deprecated\n",
driver->driver.name);
- dev_warn(&adap->dev, "Please use another way to instantiate "
- "your i2c_client\n");
+ dev_warn(&adap->dev,
+ "Please use another way to instantiate your i2c_client\n");
/* We ignore the return code; if it fails, too bad */
driver->attach_adapter(adap);
}
@@ -1691,6 +1780,12 @@ static int __process_new_adapter(struct device_driver *d, void *data)
return i2c_do_add_adapter(to_i2c_driver(d), data);
}
+static const struct i2c_lock_operations i2c_adapter_lock_ops = {
+ .lock_bus = i2c_adapter_lock_bus,
+ .trylock_bus = i2c_adapter_trylock_bus,
+ .unlock_bus = i2c_adapter_unlock_bus,
+};
+
static int i2c_register_adapter(struct i2c_adapter *adap)
{
int res = -EINVAL;
@@ -1710,11 +1805,8 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
goto out_list;
}
- if (!adap->lock_bus) {
- adap->lock_bus = i2c_adapter_lock_bus;
- adap->trylock_bus = i2c_adapter_trylock_bus;
- adap->unlock_bus = i2c_adapter_unlock_bus;
- }
+ if (!adap->lock_ops)
+ adap->lock_ops = &i2c_adapter_lock_ops;
rt_mutex_init(&adap->bus_lock);
rt_mutex_init(&adap->mux_lock);
@@ -1752,8 +1844,8 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
/* create pre-declared device nodes */
of_i2c_register_devices(adap);
- acpi_i2c_register_devices(adap);
- acpi_i2c_install_space_handler(adap);
+ i2c_acpi_register_devices(adap);
+ i2c_acpi_install_space_handler(adap);
if (adap->nr < __i2c_first_dynamic_bus_num)
i2c_scan_static_board_info(adap);
@@ -1925,7 +2017,7 @@ void i2c_del_adapter(struct i2c_adapter *adap)
return;
}
- acpi_i2c_remove_space_handler(adap);
+ i2c_acpi_remove_space_handler(adap);
/* Tell drivers about this removal */
mutex_lock(&core_lock);
bus_for_each_drv(&i2c_bus_type, NULL, adap,
@@ -2451,15 +2543,16 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
if (adap->algo->master_xfer) {
#ifdef DEBUG
for (ret = 0; ret < num; ret++) {
- dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, "
- "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD)
- ? 'R' : 'W', msgs[ret].addr, msgs[ret].len,
+ dev_dbg(&adap->dev,
+ "master_xfer[%d] %c, addr=0x%02x, len=%d%s\n",
+ ret, (msgs[ret].flags & I2C_M_RD) ? 'R' : 'W',
+ msgs[ret].addr, msgs[ret].len,
(msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : "");
}
#endif
if (in_atomic() || irqs_disabled()) {
- ret = adap->trylock_bus(adap, I2C_LOCK_SEGMENT);
+ ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT);
if (!ret)
/* I2C activity is ongoing. */
return -EAGAIN;
@@ -2619,9 +2712,9 @@ static int i2c_detect_address(struct i2c_client *temp_client,
/* Consistency check */
if (info.type[0] == '\0') {
- dev_err(&adapter->dev, "%s detection function provided "
- "no name for 0x%x\n", driver->driver.name,
- addr);
+ dev_err(&adapter->dev,
+ "%s detection function provided no name for 0x%x\n",
+ driver->driver.name, addr);
} else {
struct i2c_client *client;
@@ -2659,9 +2752,8 @@ static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
/* Warn that the adapter lost class based instantiation */
if (adapter->class == I2C_CLASS_DEPRECATED) {
dev_dbg(&adapter->dev,
- "This adapter dropped support for I2C classes and "
- "won't auto-detect %s devices anymore. If you need it, check "
- "'Documentation/i2c/instantiating-devices' for alternatives.\n",
+ "This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. "
+ "If you need it, check 'Documentation/i2c/instantiating-devices' for alternatives.\n",
driver->driver.name);
return 0;
}
@@ -2677,8 +2769,9 @@ static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
temp_client->adapter = adapter;
for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) {
- dev_dbg(&adapter->dev, "found normal entry for adapter %d, "
- "addr 0x%02x\n", adap_id, address_list[i]);
+ dev_dbg(&adapter->dev,
+ "found normal entry for adapter %d, addr 0x%02x\n",
+ adap_id, address_list[i]);
temp_client->addr = address_list[i];
err = i2c_detect_address(temp_client, driver);
if (unlikely(err))
@@ -2710,15 +2803,16 @@ i2c_new_probed_device(struct i2c_adapter *adap,
for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
/* Check address validity */
if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) {
- dev_warn(&adap->dev, "Invalid 7-bit address "
- "0x%02x\n", addr_list[i]);
+ dev_warn(&adap->dev, "Invalid 7-bit address 0x%02x\n",
+ addr_list[i]);
continue;
}
/* Check address availability (7 bit, no need to encode flags) */
if (i2c_check_addr_busy(adap, addr_list[i])) {
- dev_dbg(&adap->dev, "Address 0x%02x already in "
- "use, not probing\n", addr_list[i]);
+ dev_dbg(&adap->dev,
+ "Address 0x%02x already in use, not probing\n",
+ addr_list[i]);
continue;
}
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-15 15:11:14 +0300