Add a mechanism to let new-style i2c drivers auto-detect devices they would support and ask i2c-core to instantiate them. This is a replacement for legacy drivers, much cleaner.
Signed-off-by: Jean Delvare <[EMAIL PROTECTED]> --- This patch depends on: http://khali.linux-fr.org/devel/linux-2.6/jdelvare-i2c/i2c-use-class_for_each_device.patch http://khali.linux-fr.org/devel/linux-2.6/jdelvare-i2c/i2c-simplify-i2c_del_driver.patch Implementation note: i2c_detect and i2c_detect_address are basically clones of i2c_probe and i2c_probe_address but operating on a callback with a slightly different prototype. This duplicated code accounts for a large part of the patch, but once legacy drivers are gone, i2c_probe and i2c_probe_address will be removed, so this is no long-term duplication. drivers/i2c/i2c-core.c | 207 +++++++++++++++++++++++++++++++++++++++++++++--- include/linux/i2c.h | 14 +++ 2 files changed, 210 insertions(+), 11 deletions(-) --- linux-2.6.26-rc5.orig/include/linux/i2c.h 2008-06-05 21:04:35.000000000 +0200 +++ linux-2.6.26-rc5/include/linux/i2c.h 2008-06-05 21:54:49.000000000 +0200 @@ -43,6 +43,7 @@ struct i2c_adapter; struct i2c_client; struct i2c_driver; union i2c_smbus_data; +struct i2c_board_info; /* * The master routines are the ones normally used to transmit data to devices @@ -99,6 +100,11 @@ extern s32 i2c_smbus_write_i2c_block_dat * * The driver.owner field should be set to the module owner of this driver. * The driver.name field should be set to the name of this driver. + * + * @class: What kind of i2c device we may instantiate + * @detect: Callback for device detection + * @address_data: The I2C addresses to probe, ignore or force + * @clients: List of detected clients we created */ struct i2c_driver { @@ -140,6 +146,12 @@ struct i2c_driver { struct device_driver driver; const struct i2c_device_id *id_table; + + /* Device detection callback for automatic device creation */ + int (*detect)(struct i2c_adapter *, int address, int kind, + struct i2c_board_info *); + const struct i2c_client_address_data *address_data; + struct list_head clients; }; #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) @@ -155,6 +167,7 @@ struct i2c_driver { * @dev: Driver model device node for the slave. * @irq: indicates the IRQ generated by this device (if any) * @list: list of active/busy clients (DEPRECATED) + * @detected: member of a i2c_driver.clients list * @released: used to synchronize client releases & detaches and references * * An i2c_client identifies a single device (i.e. chip) connected to an @@ -172,6 +185,7 @@ struct i2c_client { struct device dev; /* the device structure */ int irq; /* irq issued by device (or -1) */ struct list_head list; /* DEPRECATED */ + struct list_head detected; struct completion released; }; #define to_i2c_client(d) container_of(d, struct i2c_client, dev) --- linux-2.6.26-rc5.orig/drivers/i2c/i2c-core.c 2008-06-05 21:04:35.000000000 +0200 +++ linux-2.6.26-rc5/drivers/i2c/i2c-core.c 2008-06-06 14:04:40.000000000 +0200 @@ -42,7 +42,9 @@ static DEFINE_MUTEX(core_lock); static DEFINE_IDR(i2c_adapter_idr); -#define is_newstyle_driver(d) ((d)->probe || (d)->remove) +#define is_newstyle_driver(d) ((d)->probe || (d)->remove || (d)->detect) + +static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); /* ------------------------------------------------------------------------- */ @@ -409,6 +411,10 @@ static int i2c_do_add_adapter(struct dev struct i2c_driver *driver = to_i2c_driver(d); struct i2c_adapter *adap = data; + /* Detect supported devices on that bus, and instantiate them */ + i2c_detect(adap, driver); + + /* Let legacy drivers scan this bus for matching devices */ if (driver->attach_adapter) { /* We ignore the return code; if it fails, too bad */ driver->attach_adapter(adap); @@ -448,7 +454,7 @@ static int i2c_register_adapter(struct i if (adap->nr < __i2c_first_dynamic_bus_num) i2c_scan_static_board_info(adap); - /* let legacy drivers scan this bus for matching devices */ + /* Notify drivers */ dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap, i2c_do_add_adapter); @@ -554,14 +560,26 @@ static int i2c_do_del_adapter(struct dev { struct i2c_driver *driver = to_i2c_driver(d); struct i2c_adapter *adapter = data; + struct i2c_client *client, *_n; int res; + /* Remove the devices we created ourselves */ + list_for_each_entry_safe(client, _n, &driver->clients, detected) { + if (client->adapter == adapter) { + dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", + client->name, client->addr); + list_del(&client->detected); + i2c_unregister_device(client); + } + } + if (!driver->detach_adapter) return 0; res = driver->detach_adapter(adapter); if (res) dev_err(&adapter->dev, "detach_adapter failed (%d) " "for driver [%s]\n", res, driver->driver.name); + return res; } @@ -642,7 +660,10 @@ static int __attach_adapter(struct devic struct i2c_adapter *adapter = to_i2c_adapter(dev); struct i2c_driver *driver = data; - driver->attach_adapter(adapter); + i2c_detect(adapter, driver); + + if (driver->attach_adapter) + driver->attach_adapter(adapter); return 0; } @@ -686,10 +707,10 @@ int i2c_register_driver(struct module *o pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); - /* legacy drivers scan i2c busses directly */ - if (driver->attach_adapter) - class_for_each_device(&i2c_adapter_class, driver, - __attach_adapter); + INIT_LIST_HEAD(&driver->clients); + /* Walk the adapters that are already present */ + class_for_each_device(&i2c_adapter_class, driver, + __attach_adapter); mutex_unlock(&core_lock); return 0; @@ -700,6 +721,17 @@ static int __detach_adapter(struct devic { struct i2c_adapter *adapter = to_i2c_adapter(dev); struct i2c_driver *driver = data; + struct i2c_client *client, *_n; + + list_for_each_entry_safe(client, _n, &driver->clients, detected) { + dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", + client->name, client->addr); + list_del(&client->detected); + i2c_unregister_device(client); + } + + if (is_newstyle_driver(driver)) + return 0; /* Have a look at each adapter, if clients of this driver are still * attached. If so, detach them to be able to kill the driver @@ -738,10 +770,7 @@ void i2c_del_driver(struct i2c_driver *d { mutex_lock(&core_lock); - /* legacy driver? */ - if (!is_newstyle_driver(driver)) - class_for_each_device(&i2c_adapter_class, driver, - __detach_adapter); + class_for_each_device(&i2c_adapter_class, driver, __detach_adapter); driver_unregister(&driver->driver); pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); @@ -1196,6 +1225,162 @@ int i2c_probe(struct i2c_adapter *adapte } EXPORT_SYMBOL(i2c_probe); +/* Separate detection function for new-style drivers */ +static int i2c_detect_address(struct i2c_adapter *adapter, + int addr, int kind, struct i2c_driver *driver) +{ + struct i2c_board_info info; + struct i2c_client *client; + int err; + + /* Make sure the address is valid */ + if (addr < 0x03 || addr > 0x77) { + dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", + addr); + return -EINVAL; + } + + /* Skip if already in use */ + if (i2c_check_addr(adapter, addr)) + return 0; + + /* Make sure there is something at this address, unless forced */ + if (kind < 0) { + if (i2c_smbus_xfer(adapter, addr, 0, 0, 0, + I2C_SMBUS_QUICK, NULL) < 0) + return 0; + + /* prevent 24RF08 corruption */ + if ((addr & ~0x0f) == 0x50) + i2c_smbus_xfer(adapter, addr, 0, 0, 0, + I2C_SMBUS_QUICK, NULL); + } + + /* Finally call the custom detection function */ + memset(&info, 0, sizeof(struct i2c_board_info)); + err = driver->detect(adapter, addr, kind, &info); + if (err) { + /* -ENODEV can be returned if there is a chip at the given address + but it isn't supported by this chip driver. We catch it here as + this isn't an error. */ + return err == -ENODEV ? 0 : err; + } + + /* Consistency check */ + if (info.type[0] == '\0' || info.addr != addr) { + dev_err(&adapter->dev, "Detection function returned " + "inconsistent data for 0x%x\n", addr); + } else { + /* Detection succeeded, instantiate the device */ + dev_dbg(&adapter->dev, "Creating %s at 0x%x\n", + info.type, info.addr); + client = i2c_new_device(adapter, &info); + list_add_tail(&client->detected, &driver->clients); + } + return 0; +} + +static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) +{ + const struct i2c_client_address_data *address_data; + int i, err; + int adap_id = i2c_adapter_id(adapter); + + if (!driver->detect) + return 0; + address_data = driver->address_data; + + /* Force entries are done first, and are not affected by ignore + entries */ + if (address_data->forces) { + const unsigned short * const *forces = address_data->forces; + int kind; + + for (kind = 0; forces[kind]; kind++) { + for (i = 0; forces[kind][i] != I2C_CLIENT_END; + i += 2) { + if (forces[kind][i] == adap_id + || forces[kind][i] == ANY_I2C_BUS) { + dev_dbg(&adapter->dev, "found force " + "parameter for adapter %d, " + "addr 0x%02x, kind %d\n", + adap_id, forces[kind][i + 1], + kind); + err = i2c_detect_address(adapter, + forces[kind][i + 1], + kind, driver); + if (err) + return err; + } + } + } + } + + /* Stop here if we can't use SMBUS_QUICK */ + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) { + if (address_data->probe[0] == I2C_CLIENT_END + && address_data->normal_i2c[0] == I2C_CLIENT_END) + return 0; + + dev_warn(&adapter->dev, "SMBus Quick command not supported, " + "can't probe for chips\n"); + return -EOPNOTSUPP; + } + + /* Probe entries are done second, and are not affected by ignore + entries either */ + for (i = 0; address_data->probe[i] != I2C_CLIENT_END; i += 2) { + if (address_data->probe[i] == adap_id + || address_data->probe[i] == ANY_I2C_BUS) { + dev_dbg(&adapter->dev, "found probe parameter for " + "adapter %d, addr 0x%02x\n", adap_id, + address_data->probe[i + 1]); + err = i2c_detect_address(adapter, + address_data->probe[i + 1], + -1, driver); + if (err) + return err; + } + } + + /* Stop here if the classes do not match */ + if (!(adapter->class & driver->class)) + return 0; + + /* Normal entries are done last, unless shadowed by an ignore entry */ + for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) { + int j, ignore; + + ignore = 0; + for (j = 0; address_data->ignore[j] != I2C_CLIENT_END; + j += 2) { + if ((address_data->ignore[j] == adap_id || + address_data->ignore[j] == ANY_I2C_BUS) + && address_data->ignore[j + 1] + == address_data->normal_i2c[i]) { + dev_dbg(&adapter->dev, "found ignore " + "parameter for adapter %d, " + "addr 0x%02x\n", adap_id, + address_data->ignore[j + 1]); + ignore = 1; + break; + } + } + if (ignore) + continue; + + dev_dbg(&adapter->dev, "found normal entry for adapter %d, " + "addr 0x%02x\n", adap_id, + address_data->normal_i2c[i]); + err = i2c_detect_address(adapter, address_data->normal_i2c[i], + -1, driver); + if (err) + return err; + } + + return 0; +} + struct i2c_client * i2c_new_probed_device(struct i2c_adapter *adap, struct i2c_board_info *info, -- Jean Delvare _______________________________________________ i2c mailing list [email protected] http://lists.lm-sensors.org/mailman/listinfo/i2c
