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>
This commit is contained in:
Jean Delvare
Jean Delvare
parent
97addff6de
commit
3d63430a26
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@ -7,7 +7,7 @@ drivers/gpio/pca9539.c instead.
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Supported chips:
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* Philips PCA9539
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Prefix: 'pca9539'
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Addresses scanned: 0x74 - 0x77
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Addresses scanned: none
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Datasheet:
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http://www.semiconductors.philips.com/acrobat/datasheets/PCA9539_2.pdf
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@ -23,6 +23,14 @@ The input sense can also be inverted.
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The 16 lines are split between two bytes.
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Detection
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---------
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The PCA9539 is difficult to detect and not commonly found in PC machines,
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so you have to pass the I2C bus and address of the installed PCA9539
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devices explicitly to the driver at load time via the force=... parameter.
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Sysfs entries
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-------------
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@ -14,8 +14,8 @@
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#include <linux/i2c.h>
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#include <linux/hwmon-sysfs.h>
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/* Addresses to scan */
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static unsigned short normal_i2c[] = {0x74, 0x75, 0x76, 0x77, I2C_CLIENT_END};
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/* Addresses to scan: none, device is not autodetected */
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static const unsigned short normal_i2c[] = { I2C_CLIENT_END };
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/* Insmod parameters */
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I2C_CLIENT_INSMOD_1(pca9539);
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@ -32,23 +32,6 @@ enum pca9539_cmd
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PCA9539_DIRECTION_1 = 7,
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};
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static int pca9539_attach_adapter(struct i2c_adapter *adapter);
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static int pca9539_detect(struct i2c_adapter *adapter, int address, int kind);
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static int pca9539_detach_client(struct i2c_client *client);
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/* This is the driver that will be inserted */
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static struct i2c_driver pca9539_driver = {
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.driver = {
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.name = "pca9539",
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},
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.attach_adapter = pca9539_attach_adapter,
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.detach_client = pca9539_detach_client,
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};
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struct pca9539_data {
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struct i2c_client client;
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};
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/* following are the sysfs callback functions */
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static ssize_t pca9539_show(struct device *dev, struct device_attribute *attr,
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char *buf)
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@ -105,77 +88,51 @@ static struct attribute_group pca9539_defattr_group = {
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.attrs = pca9539_attributes,
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};
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static int pca9539_attach_adapter(struct i2c_adapter *adapter)
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/* Return 0 if detection is successful, -ENODEV otherwise */
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static int pca9539_detect(struct i2c_client *client, int kind,
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struct i2c_board_info *info)
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{
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return i2c_probe(adapter, &addr_data, pca9539_detect);
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}
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/* This function is called by i2c_probe */
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static int pca9539_detect(struct i2c_adapter *adapter, int address, int kind)
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{
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struct i2c_client *client;
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struct pca9539_data *data;
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int err = 0;
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struct i2c_adapter *adapter = client->adapter;
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if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
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goto exit;
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return -ENODEV;
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/* OK. For now, we presume we have a valid client. We now create the
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client structure, even though we cannot fill it completely yet. */
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if (!(data = kzalloc(sizeof(struct pca9539_data), GFP_KERNEL))) {
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err = -ENOMEM;
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goto exit;
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}
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client = &data->client;
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i2c_set_clientdata(client, data);
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client->addr = address;
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client->adapter = adapter;
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client->driver = &pca9539_driver;
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if (kind < 0) {
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/* Detection: the pca9539 only has 8 registers (0-7).
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A read of 7 should succeed, but a read of 8 should fail. */
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if ((i2c_smbus_read_byte_data(client, 7) < 0) ||
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(i2c_smbus_read_byte_data(client, 8) >= 0))
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goto exit_kfree;
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}
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strlcpy(client->name, "pca9539", I2C_NAME_SIZE);
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/* Tell the I2C layer a new client has arrived */
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if ((err = i2c_attach_client(client)))
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goto exit_kfree;
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/* Register sysfs hooks */
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err = sysfs_create_group(&client->dev.kobj,
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&pca9539_defattr_group);
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if (err)
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goto exit_detach;
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strlcpy(info->type, "pca9539", I2C_NAME_SIZE);
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return 0;
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exit_detach:
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i2c_detach_client(client);
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exit_kfree:
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kfree(data);
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exit:
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return err;
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}
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static int pca9539_detach_client(struct i2c_client *client)
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static int pca9539_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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int err;
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/* Register sysfs hooks */
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return sysfs_create_group(&client->dev.kobj,
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&pca9539_defattr_group);
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}
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static int pca9539_remove(struct i2c_client *client)
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{
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sysfs_remove_group(&client->dev.kobj, &pca9539_defattr_group);
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if ((err = i2c_detach_client(client)))
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return err;
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kfree(i2c_get_clientdata(client));
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return 0;
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}
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static const struct i2c_device_id pca9539_id[] = {
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{ "pca9539", 0 },
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{ }
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};
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static struct i2c_driver pca9539_driver = {
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.driver = {
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.name = "pca9539",
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},
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.probe = pca9539_probe,
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.remove = pca9539_remove,
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.id_table = pca9539_id,
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.detect = pca9539_detect,
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.address_data = &addr_data,
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};
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static int __init pca9539_init(void)
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{
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return i2c_add_driver(&pca9539_driver);
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