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author | Jean Delvare <khali@linux-fr.org> | 2008-07-16 17:30:06 (GMT) |
---|---|---|
committer | Jean Delvare <khali@mahadeva.delvare> | 2008-07-16 17:30:06 (GMT) |
commit | 833bedb813689807385ae73175389c73a3f855c1 (patch) | |
tree | f9b33add52ca947fd9f8ae89753eb8d534efc70e /drivers/i2c | |
parent | 8b77e6ac4911a79993e583ece719736a9e035b1d (diff) | |
download | linux-833bedb813689807385ae73175389c73a3f855c1.tar.xz |
i2c: Convert the pcf8574 driver to a new-style i2c driver
The new-style pcf8574 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/pcf857x.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Diffstat (limited to 'drivers/i2c')
-rw-r--r-- | drivers/i2c/chips/pcf8574.c | 108 |
1 files changed, 46 insertions, 62 deletions
diff --git a/drivers/i2c/chips/pcf8574.c b/drivers/i2c/chips/pcf8574.c index 1b3db2b..6ec3098 100644 --- a/drivers/i2c/chips/pcf8574.c +++ b/drivers/i2c/chips/pcf8574.c @@ -38,37 +38,19 @@ #include <linux/slab.h> #include <linux/i2c.h> -/* Addresses to scan */ -static const unsigned short normal_i2c[] = { - 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, - 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, - I2C_CLIENT_END -}; +/* Addresses to scan: none, device can't be detected */ +static const unsigned short normal_i2c[] = { I2C_CLIENT_END }; /* Insmod parameters */ I2C_CLIENT_INSMOD_2(pcf8574, pcf8574a); /* Each client has this additional data */ struct pcf8574_data { - struct i2c_client client; - int write; /* Remember last written value */ }; -static int pcf8574_attach_adapter(struct i2c_adapter *adapter); -static int pcf8574_detect(struct i2c_adapter *adapter, int address, int kind); -static int pcf8574_detach_client(struct i2c_client *client); static void pcf8574_init_client(struct i2c_client *client); -/* This is the driver that will be inserted */ -static struct i2c_driver pcf8574_driver = { - .driver = { - .name = "pcf8574", - }, - .attach_adapter = pcf8574_attach_adapter, - .detach_client = pcf8574_detach_client, -}; - /* following are the sysfs callback functions */ static ssize_t show_read(struct device *dev, struct device_attribute *attr, char *buf) { @@ -119,41 +101,22 @@ static const struct attribute_group pcf8574_attr_group = { * Real code */ -static int pcf8574_attach_adapter(struct i2c_adapter *adapter) -{ - return i2c_probe(adapter, &addr_data, pcf8574_detect); -} - -/* This function is called by i2c_probe */ -static int pcf8574_detect(struct i2c_adapter *adapter, int address, int kind) +/* Return 0 if detection is successful, -ENODEV otherwise */ +static int pcf8574_detect(struct i2c_client *client, int kind, + struct i2c_board_info *info) { - struct i2c_client *client; - struct pcf8574_data *data; - int err = 0; - const char *client_name = ""; + struct i2c_adapter *adapter = client->adapter; + const char *client_name; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) - goto exit; - - /* 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 pcf8574_data), GFP_KERNEL))) { - err = -ENOMEM; - goto exit; - } - - client = &data->client; - i2c_set_clientdata(client, data); - client->addr = address; - client->adapter = adapter; - client->driver = &pcf8574_driver; + return -ENODEV; /* Now, we would do the remaining detection. But the PCF8574 is plainly impossible to detect! Stupid chip. */ /* Determine the chip type */ if (kind <= 0) { - if (address >= 0x38 && address <= 0x3f) + if (client->addr >= 0x38 && client->addr <= 0x3f) kind = pcf8574a; else kind = pcf8574; @@ -163,40 +126,43 @@ static int pcf8574_detect(struct i2c_adapter *adapter, int address, int kind) client_name = "pcf8574a"; else client_name = "pcf8574"; + strlcpy(info->type, client_name, I2C_NAME_SIZE); - /* Fill in the remaining client fields and put it into the global list */ - strlcpy(client->name, client_name, I2C_NAME_SIZE); + return 0; +} + +static int pcf8574_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct pcf8574_data *data; + int err; + + data = kzalloc(sizeof(struct pcf8574_data), GFP_KERNEL); + if (!data) { + err = -ENOMEM; + goto exit; + } + + i2c_set_clientdata(client, data); - /* Tell the I2C layer a new client has arrived */ - if ((err = i2c_attach_client(client))) - goto exit_free; - /* Initialize the PCF8574 chip */ pcf8574_init_client(client); /* Register sysfs hooks */ err = sysfs_create_group(&client->dev.kobj, &pcf8574_attr_group); if (err) - goto exit_detach; + goto exit_free; return 0; - exit_detach: - i2c_detach_client(client); exit_free: kfree(data); exit: return err; } -static int pcf8574_detach_client(struct i2c_client *client) +static int pcf8574_remove(struct i2c_client *client) { - int err; - sysfs_remove_group(&client->dev.kobj, &pcf8574_attr_group); - - if ((err = i2c_detach_client(client))) - return err; - kfree(i2c_get_clientdata(client)); return 0; } @@ -208,6 +174,24 @@ static void pcf8574_init_client(struct i2c_client *client) data->write = -EAGAIN; } +static const struct i2c_device_id pcf8574_id[] = { + { "pcf8574", 0 }, + { "pcf8574a", 0 }, + { } +}; + +static struct i2c_driver pcf8574_driver = { + .driver = { + .name = "pcf8574", + }, + .probe = pcf8574_probe, + .remove = pcf8574_remove, + .id_table = pcf8574_id, + + .detect = pcf8574_detect, + .address_data = &addr_data, +}; + static int __init pcf8574_init(void) { return i2c_add_driver(&pcf8574_driver); |