diff options
Diffstat (limited to 'Documentation/i2c')
| -rw-r--r-- | Documentation/i2c/busses/i2c-nforce2 | 3 | ||||
| -rw-r--r-- | Documentation/i2c/busses/i2c-parport | 1 | ||||
| -rw-r--r-- | Documentation/i2c/porting-clients | 90 | ||||
| -rw-r--r-- | Documentation/i2c/writing-clients | 20 |
4 files changed, 62 insertions, 52 deletions
diff --git a/Documentation/i2c/busses/i2c-nforce2 b/Documentation/i2c/busses/i2c-nforce2 index e379e182e64..d751282d9b2 100644 --- a/Documentation/i2c/busses/i2c-nforce2 +++ b/Documentation/i2c/busses/i2c-nforce2 @@ -5,7 +5,8 @@ Supported adapters: * nForce2 Ultra 400 MCP 10de:0084 * nForce3 Pro150 MCP 10de:00D4 * nForce3 250Gb MCP 10de:00E4 - * nForce4 MCP 10de:0052 + * nForce4 MCP 10de:0052 + * nForce4 MCP-04 10de:0034 Datasheet: not publically available, but seems to be similar to the AMD-8111 SMBus 2.0 adapter. diff --git a/Documentation/i2c/busses/i2c-parport b/Documentation/i2c/busses/i2c-parport index 9f1d0082da1..d9f23c0763f 100644 --- a/Documentation/i2c/busses/i2c-parport +++ b/Documentation/i2c/busses/i2c-parport @@ -17,6 +17,7 @@ It currently supports the following devices: * Velleman K8000 adapter * ELV adapter * Analog Devices evaluation boards (ADM1025, ADM1030, ADM1031, ADM1032) + * Barco LPT->DVI (K5800236) adapter These devices use different pinout configurations, so you have to tell the driver what you have, using the type module parameter. There is no diff --git a/Documentation/i2c/porting-clients b/Documentation/i2c/porting-clients index 184fac2377a..f03c2a02f80 100644 --- a/Documentation/i2c/porting-clients +++ b/Documentation/i2c/porting-clients @@ -1,10 +1,13 @@ -Revision 5, 2005-07-29 +Revision 6, 2005-11-20 Jean Delvare <khali@linux-fr.org> Greg KH <greg@kroah.com> This is a guide on how to convert I2C chip drivers from Linux 2.4 to Linux 2.6. I have been using existing drivers (lm75, lm78) as examples. Then I converted a driver myself (lm83) and updated this document. +Note that this guide is strongly oriented towards hardware monitoring +drivers. Many points are still valid for other type of drivers, but +others may be irrelevant. There are two sets of points below. The first set concerns technical changes. The second set concerns coding policy. Both are mandatory. @@ -22,16 +25,20 @@ Technical changes: #include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> + #include <linux/jiffies.h> #include <linux/i2c.h> + #include <linux/i2c-isa.h> /* for ISA drivers */ #include <linux/hwmon.h> /* for hardware monitoring drivers */ #include <linux/hwmon-sysfs.h> #include <linux/hwmon-vid.h> /* if you need VRM support */ + #include <linux/err.h> /* for class registration */ #include <asm/io.h> /* if you have I/O operations */ Please respect this inclusion order. Some extra headers may be required for a given driver (e.g. "lm75.h"). * [Addresses] SENSORS_I2C_END becomes I2C_CLIENT_END, ISA addresses - are no more handled by the i2c core. + are no more handled by the i2c core. Address ranges are no more + supported either, define each individual address separately. SENSORS_INSMOD_<n> becomes I2C_CLIENT_INSMOD_<n>. * [Client data] Get rid of sysctl_id. Try using standard names for @@ -48,23 +55,23 @@ Technical changes: int kind); static void lm75_init_client(struct i2c_client *client); static int lm75_detach_client(struct i2c_client *client); - static void lm75_update_client(struct i2c_client *client); + static struct lm75_data lm75_update_device(struct device *dev); * [Sysctl] All sysctl stuff is of course gone (defines, ctl_table and functions). Instead, you have to define show and set functions for each sysfs file. Only define set for writable values. Take a look at an - existing 2.6 driver for details (lm78 for example). Don't forget + existing 2.6 driver for details (it87 for example). Don't forget to define the attributes for each file (this is that step that links callback functions). Use the file names specified in - Documentation/i2c/sysfs-interface for the individual files. Also + Documentation/hwmon/sysfs-interface for the individual files. Also convert the units these files read and write to the specified ones. If you need to add a new type of file, please discuss it on the sensors mailing list <lm-sensors@lm-sensors.org> by providing a - patch to the Documentation/i2c/sysfs-interface file. + patch to the Documentation/hwmon/sysfs-interface file. * [Attach] For I2C drivers, the attach function should make sure - that the adapter's class has I2C_CLASS_HWMON, using the - following construct: + that the adapter's class has I2C_CLASS_HWMON (or whatever class is + suitable for your driver), using the following construct: if (!(adapter->class & I2C_CLASS_HWMON)) return 0; ISA-only drivers of course don't need this. @@ -72,63 +79,72 @@ Technical changes: * [Detect] As mentioned earlier, the flags parameter is gone. The type_name and client_name strings are replaced by a single - name string, which will be filled with a lowercase, short string - (typically the driver name, e.g. "lm75"). + name string, which will be filled with a lowercase, short string. In i2c-only drivers, drop the i2c_is_isa_adapter check, it's useless. Same for isa-only drivers, as the test would always be true. Only hybrid drivers (which are quite rare) still need it. - The errorN labels are reduced to the number needed. If that number - is 2 (i2c-only drivers), it is advised that the labels are named - exit and exit_free. For i2c+isa drivers, labels should be named - ERROR0, ERROR1 and ERROR2. Don't forget to properly set err before + The labels used for error paths are reduced to the number needed. + It is advised that the labels are given descriptive names such as + exit and exit_free. Don't forget to properly set err before jumping to error labels. By the way, labels should be left-aligned. Use kzalloc instead of kmalloc. Use i2c_set_clientdata to set the client data (as opposed to a direct access to client->data). - Use strlcpy instead of strcpy to copy the client name. + Use strlcpy instead of strcpy or snprintf to copy the client name. Replace the sysctl directory registration by calls to device_create_file. Move the driver initialization before any sysfs file creation. + Register the client with the hwmon class (using hwmon_device_register) + if applicable. Drop client->id. Drop any 24RF08 corruption prevention you find, as this is now done at the i2c-core level, and doing it twice voids it. + Don't add I2C_CLIENT_ALLOW_USE to client->flags, it's the default now. * [Init] Limits must not be set by the driver (can be done later in user-space). Chip should not be reset default (although a module - parameter may be used to force is), and initialization should be + parameter may be used to force it), and initialization should be limited to the strictly necessary steps. -* [Detach] Get rid of data, remove the call to - i2c_deregister_entry. Do not log an error message if - i2c_detach_client fails, as i2c-core will now do it for you. - -* [Update] Don't access client->data directly, use - i2c_get_clientdata(client) instead. - -* [Interface] Init function should not print anything. Make sure - there is a MODULE_LICENSE() line, at the bottom of the file - (after MODULE_AUTHOR() and MODULE_DESCRIPTION(), in this order). +* [Detach] Remove the call to i2c_deregister_entry. Do not log an + error message if i2c_detach_client fails, as i2c-core will now do + it for you. + Unregister from the hwmon class if applicable. + +* [Update] The function prototype changed, it is now + passed a device structure, which you have to convert to a client + using to_i2c_client(dev). The update function should return a + pointer to the client data. + Don't access client->data directly, use i2c_get_clientdata(client) + instead. + Use time_after() instead of direct jiffies comparison. + +* [Interface] Make sure there is a MODULE_LICENSE() line, at the bottom + of the file (after MODULE_AUTHOR() and MODULE_DESCRIPTION(), in this + order). + +* [Driver] The flags field of the i2c_driver structure is gone. + I2C_DF_NOTIFY is now the default behavior. + The i2c_driver structure has a driver member, which is itself a + structure, those name member should be initialized to a driver name + string. i2c_driver itself has no name member anymore. Coding policy: * [Copyright] Use (C), not (c), for copyright. * [Debug/log] Get rid of #ifdef DEBUG/#endif constructs whenever you - can. Calls to printk/pr_debug for debugging purposes are replaced - by calls to dev_dbg. Here is an example on how to call it (taken - from lm75_detect): + can. Calls to printk for debugging purposes are replaced by calls to + dev_dbg where possible, else to pr_debug. Here is an example of how + to call it (taken from lm75_detect): dev_dbg(&client->dev, "Starting lm75 update\n"); Replace other printk calls with the dev_info, dev_err or dev_warn function, as appropriate. -* [Constants] Constants defines (registers, conversions, initial - values) should be aligned. This greatly improves readability. - Same goes for variables declarations. Alignments are achieved by the - means of tabs, not spaces. Remember that tabs are set to 8 in the - Linux kernel code. - -* [Structure definition] The name field should be standardized. All - lowercase and as simple as the driver name itself (e.g. "lm75"). +* [Constants] Constants defines (registers, conversions) should be + aligned. This greatly improves readability. + Alignments are achieved by the means of tabs, not spaces. Remember + that tabs are set to 8 in the Linux kernel code. * [Layout] Avoid extra empty lines between comments and what they comment. Respect the coding style (see Documentation/CodingStyle), diff --git a/Documentation/i2c/writing-clients b/Documentation/i2c/writing-clients index d19993cc060..3a057c8e550 100644 --- a/Documentation/i2c/writing-clients +++ b/Documentation/i2c/writing-clients @@ -25,9 +25,9 @@ routines, a client structure specific information like the actual I2C address. static struct i2c_driver foo_driver = { - .owner = THIS_MODULE, - .name = "Foo version 2.3 driver", - .flags = I2C_DF_NOTIFY, + .driver = { + .name = "foo", + }, .attach_adapter = &foo_attach_adapter, .detach_client = &foo_detach_client, .command = &foo_command /* may be NULL */ @@ -36,10 +36,6 @@ static struct i2c_driver foo_driver = { The name field must match the driver name, including the case. It must not contain spaces, and may be up to 31 characters long. -Don't worry about the flags field; just put I2C_DF_NOTIFY into it. This -means that your driver will be notified when new adapters are found. -This is almost always what you want. - All other fields are for call-back functions which will be explained below. @@ -496,17 +492,13 @@ Note that some functions are marked by `__init', and some data structures by `__init_data'. Hose functions and structures can be removed after kernel booting (or module loading) is completed. + Command function ================ A generic ioctl-like function call back is supported. You will seldom -need this. You may even set it to NULL. - - /* No commands defined */ - int foo_command(struct i2c_client *client, unsigned int cmd, void *arg) - { - return 0; - } +need this, and its use is deprecated anyway, so newer design should not +use it. Set it to NULL. Sending and receiving |