i2c: Convert the pca9539 driver to a new-style i2c driver
The new-style pca9539 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Warning: users will now have to use the force module parameter to get
the driver to attach to their device. That's not a bad thing as these
devices can't be detected anyway.
Note that this doesn't change the fact that this driver is deprecated
in favor of gpio/pca953x.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/Documentation/i2c/chips/pca9539 b/Documentation/i2c/chips/pca9539
index 1d81c53..6aff890 100644
--- a/Documentation/i2c/chips/pca9539
+++ b/Documentation/i2c/chips/pca9539
@@ -7,7 +7,7 @@
Supported chips:
* Philips PCA9539
Prefix: 'pca9539'
- Addresses scanned: 0x74 - 0x77
+ Addresses scanned: none
Datasheet:
http://www.semiconductors.philips.com/acrobat/datasheets/PCA9539_2.pdf
@@ -23,6 +23,14 @@
The 16 lines are split between two bytes.
+Detection
+---------
+
+The PCA9539 is difficult to detect and not commonly found in PC machines,
+so you have to pass the I2C bus and address of the installed PCA9539
+devices explicitly to the driver at load time via the force=... parameter.
+
+
Sysfs entries
-------------
diff --git a/drivers/i2c/chips/pca9539.c b/drivers/i2c/chips/pca9539.c
index 58ab7f2..270de4e 100644
--- a/drivers/i2c/chips/pca9539.c
+++ b/drivers/i2c/chips/pca9539.c
@@ -14,8 +14,8 @@
#include <linux/i2c.h>
#include <linux/hwmon-sysfs.h>
-/* Addresses to scan */
-static unsigned short normal_i2c[] = {0x74, 0x75, 0x76, 0x77, I2C_CLIENT_END};
+/* Addresses to scan: none, device is not autodetected */
+static const unsigned short normal_i2c[] = { I2C_CLIENT_END };
/* Insmod parameters */
I2C_CLIENT_INSMOD_1(pca9539);
@@ -32,23 +32,6 @@
PCA9539_DIRECTION_1 = 7,
};
-static int pca9539_attach_adapter(struct i2c_adapter *adapter);
-static int pca9539_detect(struct i2c_adapter *adapter, int address, int kind);
-static int pca9539_detach_client(struct i2c_client *client);
-
-/* This is the driver that will be inserted */
-static struct i2c_driver pca9539_driver = {
- .driver = {
- .name = "pca9539",
- },
- .attach_adapter = pca9539_attach_adapter,
- .detach_client = pca9539_detach_client,
-};
-
-struct pca9539_data {
- struct i2c_client client;
-};
-
/* following are the sysfs callback functions */
static ssize_t pca9539_show(struct device *dev, struct device_attribute *attr,
char *buf)
@@ -105,77 +88,51 @@
.attrs = pca9539_attributes,
};
-static int pca9539_attach_adapter(struct i2c_adapter *adapter)
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int pca9539_detect(struct i2c_client *client, int kind,
+ struct i2c_board_info *info)
{
- return i2c_probe(adapter, &addr_data, pca9539_detect);
-}
-
-/* This function is called by i2c_probe */
-static int pca9539_detect(struct i2c_adapter *adapter, int address, int kind)
-{
- struct i2c_client *client;
- struct pca9539_data *data;
- int err = 0;
+ struct i2c_adapter *adapter = client->adapter;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
- goto exit;
+ return -ENODEV;
- /* OK. For now, we presume we have a valid client. We now create the
- client structure, even though we cannot fill it completely yet. */
- if (!(data = kzalloc(sizeof(struct pca9539_data), GFP_KERNEL))) {
- err = -ENOMEM;
- goto exit;
- }
-
- client = &data->client;
- i2c_set_clientdata(client, data);
- client->addr = address;
- client->adapter = adapter;
- client->driver = &pca9539_driver;
-
- if (kind < 0) {
- /* Detection: the pca9539 only has 8 registers (0-7).
- A read of 7 should succeed, but a read of 8 should fail. */
- if ((i2c_smbus_read_byte_data(client, 7) < 0) ||
- (i2c_smbus_read_byte_data(client, 8) >= 0))
- goto exit_kfree;
- }
-
- strlcpy(client->name, "pca9539", I2C_NAME_SIZE);
-
- /* Tell the I2C layer a new client has arrived */
- if ((err = i2c_attach_client(client)))
- goto exit_kfree;
-
- /* Register sysfs hooks */
- err = sysfs_create_group(&client->dev.kobj,
- &pca9539_defattr_group);
- if (err)
- goto exit_detach;
+ strlcpy(info->type, "pca9539", I2C_NAME_SIZE);
return 0;
-
-exit_detach:
- i2c_detach_client(client);
-exit_kfree:
- kfree(data);
-exit:
- return err;
}
-static int pca9539_detach_client(struct i2c_client *client)
+static int pca9539_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
{
- int err;
+ /* Register sysfs hooks */
+ return sysfs_create_group(&client->dev.kobj,
+ &pca9539_defattr_group);
+}
+static int pca9539_remove(struct i2c_client *client)
+{
sysfs_remove_group(&client->dev.kobj, &pca9539_defattr_group);
-
- if ((err = i2c_detach_client(client)))
- return err;
-
- kfree(i2c_get_clientdata(client));
return 0;
}
+static const struct i2c_device_id pca9539_id[] = {
+ { "pca9539", 0 },
+ { }
+};
+
+static struct i2c_driver pca9539_driver = {
+ .driver = {
+ .name = "pca9539",
+ },
+ .probe = pca9539_probe,
+ .remove = pca9539_remove,
+ .id_table = pca9539_id,
+
+ .detect = pca9539_detect,
+ .address_data = &addr_data,
+};
+
static int __init pca9539_init(void)
{
return i2c_add_driver(&pca9539_driver);
