[Patch V3 5/5] I2C/ACPI: Clean up I2C ACPI code and Add CONFIG_I2C_ACPI config

From: Lan Tianyu
Date: Tue May 20 2014 - 09:00:21 EST


Clean up ACPI related code in the i2c core and add CONFIG_I2C_ACPI
to enable I2C ACPI code.

Current there is a race between removing I2C ACPI operation region
and ACPI AML code accessing. So make i2c core built-in if CONFIG_I2C_ACPI
is set.

Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Signed-off-by: Lan Tianyu <tianyu.lan@xxxxxxxxx>
---
drivers/i2c/Kconfig | 18 +++++++++-
drivers/i2c/Makefile | 2 +-
drivers/i2c/i2c-acpi.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++
drivers/i2c/i2c-core.c | 95 --------------------------------------------------
include/linux/i2c.h | 4 ++-
5 files changed, 110 insertions(+), 98 deletions(-)

diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
index 7b7ea32..3e3b680 100644
--- a/drivers/i2c/Kconfig
+++ b/drivers/i2c/Kconfig
@@ -2,7 +2,9 @@
# I2C subsystem configuration
#

-menuconfig I2C
+menu "I2C support"
+
+config I2C
tristate "I2C support"
select RT_MUTEXES
---help---
@@ -21,6 +23,18 @@ menuconfig I2C
This I2C support can also be built as a module. If so, the module
will be called i2c-core.

+config I2C_ACPI
+ bool "I2C ACPI support"
+ select I2C
+ depends on ACPI
+ default y
+ help
+ Say Y here if you want to enable ACPI I2C support. This includes support
+ for automatic enumeration of I2C slave devices and support for ACPI I2C
+ Operation Regions. Operation Regions allow firmware (BIOS) code to
+ access I2C slave devices, such as smart batteries through an I2C host
+ controller driver.
+
if I2C

config I2C_BOARDINFO
@@ -124,3 +138,5 @@ config I2C_DEBUG_BUS
on.

endif # I2C
+
+endmenu
diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index 80db307..a1f590c 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -3,7 +3,7 @@
#

i2ccore-y := i2c-core.o
-i2ccore-$(CONFIG_ACPI) += i2c-acpi.o
+i2ccore-$(CONFIG_I2C_ACPI) += i2c-acpi.o

obj-$(CONFIG_I2C_BOARDINFO) += i2c-boardinfo.o
obj-$(CONFIG_I2C) += i2ccore.o
diff --git a/drivers/i2c/i2c-acpi.c b/drivers/i2c/i2c-acpi.c
index f7f4c89..e8b6196 100644
--- a/drivers/i2c/i2c-acpi.c
+++ b/drivers/i2c/i2c-acpi.c
@@ -37,6 +37,95 @@ struct gsb_buffer {
};
} __packed;

+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.
+ */
+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");
+}
+
static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
u8 cmd, u8 *data, u8 data_len)
{
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index e25cb84..4ccff11 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1092,101 +1092,6 @@ EXPORT_SYMBOL(of_find_i2c_adapter_by_node);
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)
{
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index f7a939a..ea50766 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -577,10 +577,12 @@ static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node
}
#endif /* CONFIG_OF */

-#ifdef CONFIG_ACPI
+#ifdef CONFIG_I2C_ACPI
int acpi_i2c_install_space_handler(struct i2c_adapter *adapter);
void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter);
+void acpi_i2c_register_devices(struct i2c_adapter *adap);
#else
+static inline void acpi_i2c_register_devices(struct i2c_adapter *adap) { }
static inline void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter)
{ }
static inline int acpi_i2c_install_space_handler(struct i2c_adapter *adapter)
--
1.8.3.1

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