[PATCH 1/5] Implement module aliasing for i2c to translate from device tree names
Jon Smirl
jonsmirl at gmail.com
Thu Dec 20 15:41:38 EST 2007
This patch allows new style i2c chip drivers to have alias names using
the official kernel aliasing system and MODULE_DEVICE_TABLE(). I've
tested it on PowerPC and x86. This change is required for PowerPC
device tree support.
Signed-off-by: Jon Smirl <jonsmirl at gmail.com>
---
drivers/i2c/i2c-core.c | 32 ++++++++++++++++++++++++++------
include/linux/i2c.h | 9 ++++-----
include/linux/mod_devicetable.h | 20 ++++++++++++++++++++
scripts/mod/file2alias.c | 19 +++++++++++++++++++
4 files changed, 69 insertions(+), 11 deletions(-)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index b5e13e4..fce06fd 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -47,10 +47,25 @@ static DEFINE_IDR(i2c_adapter_idr);
/* ------------------------------------------------------------------------- */
-static int i2c_device_match(struct device *dev, struct device_driver *drv)
+static const struct i2c_device_id *i2c_device_match(const struct i2c_device_id *id, struct i2c_client *client)
+{
+ /* only powerpc drivers implement the id_table,
+ * it is empty on other platforms */
+ if (id) {
+ while (id->name[0]) {
+ if (strcmp(client->driver_name, id->name) == 0)
+ return id;
+ id++;
+ }
+ }
+ return NULL;
+}
+
+static int i2c_bus_match(struct device *dev, struct device_driver *drv)
{
struct i2c_client *client = to_i2c_client(dev);
struct i2c_driver *driver = to_i2c_driver(drv);
+ const struct i2c_device_id *found_id;
/* make legacy i2c drivers bypass driver model probing entirely;
* such drivers scan each i2c adapter/bus themselves.
@@ -58,9 +73,11 @@ static int i2c_device_match(struct device *dev, struct device_driver *drv)
if (!is_newstyle_driver(driver))
return 0;
- /* new style drivers use the same kind of driver matching policy
- * as platform devices or SPI: compare device and driver IDs.
- */
+ /* match on an id table if there is one */
+ found_id = i2c_device_match(driver->id_table, client);
+ if (found_id)
+ return 1;
+
return strcmp(client->driver_name, drv->name) == 0;
}
@@ -89,12 +106,15 @@ static int i2c_device_probe(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct i2c_driver *driver = to_i2c_driver(dev->driver);
+ const struct i2c_device_id *id;
if (!driver->probe)
return -ENODEV;
client->driver = driver;
dev_dbg(dev, "probe\n");
- return driver->probe(client);
+
+ id = i2c_device_match(driver->id_table, client);
+ return driver->probe(client, id);
}
static int i2c_device_remove(struct device *dev)
@@ -189,7 +209,7 @@ static struct device_attribute i2c_dev_attrs[] = {
static struct bus_type i2c_bus_type = {
.name = "i2c",
.dev_attrs = i2c_dev_attrs,
- .match = i2c_device_match,
+ .match = i2c_bus_match,
.uevent = i2c_device_uevent,
.probe = i2c_device_probe,
.remove = i2c_device_remove,
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index a100c9f..49fc682 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -126,7 +126,7 @@ struct i2c_driver {
* With the driver model, device enumeration is NEVER done by drivers;
* it's done by infrastructure. (NEW STYLE DRIVERS ONLY)
*/
- int (*probe)(struct i2c_client *);
+ int (*probe)(struct i2c_client *, const struct i2c_device_id *id);
int (*remove)(struct i2c_client *);
/* driver model interfaces that don't relate to enumeration */
@@ -141,11 +141,10 @@ struct i2c_driver {
struct device_driver driver;
struct list_head list;
+ struct i2c_device_id *id_table;
};
#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
-#define I2C_NAME_SIZE 20
-
/**
* struct i2c_client - represent an I2C slave device
* @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
@@ -179,7 +178,7 @@ struct i2c_client {
/* to the client */
struct device dev; /* the device structure */
int irq; /* irq issued by device (or -1) */
- char driver_name[KOBJ_NAME_LEN];
+ char driver_name[I2C_NAME_SIZE];
struct list_head list;
struct completion released;
};
@@ -223,7 +222,7 @@ static inline void i2c_set_clientdata (struct i2c_client *dev, void *data)
* with the adapter already known.
*/
struct i2c_board_info {
- char driver_name[KOBJ_NAME_LEN];
+ char driver_name[I2C_NAME_SIZE];
char type[I2C_NAME_SIZE];
unsigned short flags;
unsigned short addr;
diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index e9fddb4..d66038a 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -367,4 +367,24 @@ struct virtio_device_id {
};
#define VIRTIO_DEV_ANY_ID 0xffffffff
+/* i2c */
+
+/* These defines are used to separate PowerPC open firmware
+ * drivers into their own namespace */
+#define I2C_NAME_SIZE (16*3)
+#define I2C_MODULE_PREFIX "i2c:N"
+#ifdef CONFIG_OF
+#define OF_I2C_PREFIX "OF,"
+#define I2C_OF_MODULE_PREFIX I2C_MODULE_PREFIX OF_I2C_PREFIX
+#define OF_I2C_ID(s,d) {OF_I2C_PREFIX s, (d) },
+#else
+#define OF_I2C_ID(s,d)
+#endif
+
+struct i2c_device_id {
+ char name[I2C_NAME_SIZE];
+ kernel_ulong_t driver_data; /* Data private to the driver */
+};
+
+
#endif /* LINUX_MOD_DEVICETABLE_H */
diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
index d802b5a..da43742 100644
--- a/scripts/mod/file2alias.c
+++ b/scripts/mod/file2alias.c
@@ -539,6 +539,21 @@ static int do_virtio_entry(const char *filename, struct virtio_device_id *id,
return 1;
}
+/* Looks like: i2c:Ns */
+static int do_i2c_entry(const char *filename, struct i2c_device_id *id,
+ char *alias)
+{
+ char *tmp;
+ sprintf (alias, I2C_MODULE_PREFIX "%s", id->name);
+
+ /* Replace all whitespace with underscores */
+ for (tmp = alias; tmp && *tmp; tmp++)
+ if (isspace (*tmp))
+ *tmp = '_';
+
+ return 1;
+}
+
/* Ignore any prefix, eg. v850 prepends _ */
static inline int sym_is(const char *symbol, const char *name)
{
@@ -669,6 +684,10 @@ void handle_moddevtable(struct module *mod, struct elf_info *info,
do_table(symval, sym->st_size,
sizeof(struct virtio_device_id), "virtio",
do_virtio_entry, mod);
+ else if (sym_is(symname, "__mod_i2c_device_table"))
+ do_table(symval, sym->st_size,
+ sizeof(struct i2c_device_id), "i2c",
+ do_i2c_entry, mod);
free(zeros);
}
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