/* i2c Support for Apple SMU Controller Copyright (c) 2005 Benjamin Herrenschmidt, IBM Corp. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include #include #include #include #include #include #include #include #include MODULE_AUTHOR("Benjamin Herrenschmidt "); MODULE_DESCRIPTION("I2C driver for Apple PowerMac"); MODULE_LICENSE("GPL"); /* * SMBUS-type transfer entrypoint */ static s32 i2c_powermac_smbus_xfer( struct i2c_adapter* adap, u16 addr, unsigned short flags, char read_write, u8 command, int size, union i2c_smbus_data* data) { struct pmac_i2c_bus *bus = i2c_get_adapdata(adap); int rc = 0; int read = (read_write == I2C_SMBUS_READ); int addrdir = (addr << 1) | read; int mode, subsize, len; u32 subaddr; u8 *buf; u8 local[2]; if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE) { mode = pmac_i2c_mode_std; subsize = 0; subaddr = 0; } else { mode = read ? pmac_i2c_mode_combined : pmac_i2c_mode_stdsub; subsize = 1; subaddr = command; } switch (size) { case I2C_SMBUS_QUICK: buf = NULL; len = 0; break; case I2C_SMBUS_BYTE: case I2C_SMBUS_BYTE_DATA: buf = &data->byte; len = 1; break; case I2C_SMBUS_WORD_DATA: if (!read) { local[0] = data->word & 0xff; local[1] = (data->word >> 8) & 0xff; } buf = local; len = 2; break; /* Note that these are broken vs. the expected smbus API where * on reads, the length is actually returned from the function, * but I think the current API makes no sense and I don't want * any driver that I haven't verified for correctness to go * anywhere near a pmac i2c bus anyway ... * * I'm also not completely sure what kind of phases to do between * the actual command and the data (what I am _supposed_ to do that * is). For now, I assume writes are a single stream and reads have * a repeat start/addr phase (but not stop in between) */ case I2C_SMBUS_BLOCK_DATA: buf = data->block; len = data->block[0] + 1; break; case I2C_SMBUS_I2C_BLOCK_DATA: buf = &data->block[1]; len = data->block[0]; break; default: return -EINVAL; } rc = pmac_i2c_open(bus, 0); if (rc) { dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc); return rc; } rc = pmac_i2c_setmode(bus, mode); if (rc) { dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n", mode, rc); goto bail; } rc = pmac_i2c_xfer(bus, addrdir, subsize, subaddr, buf, len); if (rc) { if (rc == -ENXIO) dev_dbg(&adap->dev, "I2C transfer at 0x%02x failed, size %d, " "err %d\n", addrdir >> 1, size, rc); else dev_err(&adap->dev, "I2C transfer at 0x%02x failed, size %d, " "err %d\n", addrdir >> 1, size, rc); goto bail; } if (size == I2C_SMBUS_WORD_DATA && read) { data->word = ((u16)local[1]) << 8; data->word |= local[0]; } bail: pmac_i2c_close(bus); return rc; } /* * Generic i2c master transfer entrypoint. This driver only support single * messages (for "lame i2c" transfers). Anything else should use the smbus * entry point */ static int i2c_powermac_master_xfer( struct i2c_adapter *adap, struct i2c_msg *msgs, int num) { struct pmac_i2c_bus *bus = i2c_get_adapdata(adap); int rc = 0; int read; int addrdir; if (num != 1) { dev_err(&adap->dev, "Multi-message I2C transactions not supported\n"); return -EOPNOTSUPP; } if (msgs->flags & I2C_M_TEN) return -EINVAL; read = (msgs->flags & I2C_M_RD) != 0; addrdir = (msgs->addr << 1) | read; rc = pmac_i2c_open(bus, 0); if (rc) { dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc); return rc; } rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std); if (rc) { dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n", pmac_i2c_mode_std, rc); goto bail; } rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len); if (rc < 0) { if (rc == -ENXIO) dev_dbg(&adap->dev, "I2C %s 0x%02x failed, err %d\n", addrdir & 1 ? "read from" : "write to", addrdir >> 1, rc); else dev_err(&adap->dev, "I2C %s 0x%02x failed, err %d\n", addrdir & 1 ? "read from" : "write to", addrdir >> 1, rc); } bail: pmac_i2c_close(bus); return rc < 0 ? rc : 1; } static u32 i2c_powermac_func(struct i2c_adapter * adapter) { return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_I2C; } /* For now, we only handle smbus */ static const struct i2c_algorithm i2c_powermac_algorithm = { .smbus_xfer = i2c_powermac_smbus_xfer, .master_xfer = i2c_powermac_master_xfer, .functionality = i2c_powermac_func, }; static int __devexit i2c_powermac_remove(struct platform_device *dev) { struct i2c_adapter *adapter = platform_get_drvdata(dev); int rc; rc = i2c_del_adapter(adapter); /* We aren't that prepared to deal with this... */ if (rc) printk(KERN_WARNING "i2c-powermac.c: Failed to remove bus %s !\n", adapter->name); platform_set_drvdata(dev, NULL); memset(adapter, 0, sizeof(*adapter)); return 0; } static int __devinit i2c_powermac_probe(struct platform_device *dev) { struct pmac_i2c_bus *bus = dev->dev.platform_data; struct device_node *parent = NULL; struct i2c_adapter *adapter; const char *basename; int rc; if (bus == NULL) return -EINVAL; adapter = pmac_i2c_get_adapter(bus); /* Ok, now we need to make up a name for the interface that will * match what we used to do in the past, that is basically the * controller's parent device node for keywest. PMU didn't have a * naming convention and SMU has a different one */ switch(pmac_i2c_get_type(bus)) { case pmac_i2c_bus_keywest: parent = of_get_parent(pmac_i2c_get_controller(bus)); if (parent == NULL) return -EINVAL; basename = parent->name; break; case pmac_i2c_bus_pmu: basename = "pmu"; break; case pmac_i2c_bus_smu: /* This is not what we used to do but I'm fixing drivers at * the same time as this change */ basename = "smu"; break; default: return -EINVAL; } snprintf(adapter->name, sizeof(adapter->name), "%s %d", basename, pmac_i2c_get_channel(bus)); of_node_put(parent); platform_set_drvdata(dev, adapter); adapter->algo = &i2c_powermac_algorithm; i2c_set_adapdata(adapter, bus); adapter->dev.parent = &dev->dev; rc = i2c_add_adapter(adapter); if (rc) { printk(KERN_ERR "i2c-powermac: Adapter %s registration " "failed\n", adapter->name); memset(adapter, 0, sizeof(*adapter)); } printk(KERN_INFO "PowerMac i2c bus %s registered\n", adapter->name); if (!strncmp(basename, "uni-n", 5)) { struct device_node *np; const u32 *prop; struct i2c_board_info info; /* Instantiate I2C motion sensor if present */ np = of_find_node_by_name(NULL, "accelerometer"); if (np && of_device_is_compatible(np, "AAPL,accelerometer_1") && (prop = of_get_property(np, "reg", NULL))) { int i2c_bus; const char *tmp_bus; /* look for bus either using "reg" or by path */ tmp_bus = strstr(np->full_name, "/i2c-bus@"); if (tmp_bus) i2c_bus = *(tmp_bus + 9) - '0'; else i2c_bus = ((*prop) >> 8) & 0x0f; if (pmac_i2c_get_channel(bus) == i2c_bus) { memset(&info, 0, sizeof(struct i2c_board_info)); info.addr = ((*prop) & 0xff) >> 1; strlcpy(info.type, "ams", I2C_NAME_SIZE); i2c_new_device(adapter, &info); } } } return rc; } /* work with hotplug and coldplug */ MODULE_ALIAS("platform:i2c-powermac"); static struct platform_driver i2c_powermac_driver = { .probe = i2c_powermac_probe, .remove = __devexit_p(i2c_powermac_remove), .driver = { .name = "i2c-powermac", .bus = &platform_bus_type, }, }; static int __init i2c_powermac_init(void) { platform_driver_register(&i2c_powermac_driver); return 0; } static void __exit i2c_powermac_cleanup(void) { platform_driver_unregister(&i2c_powermac_driver); } module_init(i2c_powermac_init); module_exit(i2c_powermac_cleanup);