diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-powermac.c')
-rw-r--r-- | drivers/i2c/busses/i2c-powermac.c | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-powermac.c b/drivers/i2c/busses/i2c-powermac.c new file mode 100644 index 00000000000..df786eb5529 --- /dev/null +++ b/drivers/i2c/busses/i2c-powermac.c @@ -0,0 +1,290 @@ +/* + i2c Support for Apple SMU Controller + + Copyright (c) 2005 Benjamin Herrenschmidt, IBM Corp. + <benh@kernel.crashing.org> + + 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 <linux/config.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/completion.h> +#include <linux/device.h> +#include <linux/platform_device.h> +#include <asm/prom.h> +#include <asm/pmac_low_i2c.h> + +MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); +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; + u8 local[2]; + + rc = pmac_i2c_open(bus, 0); + if (rc) + return rc; + + switch (size) { + case I2C_SMBUS_QUICK: + rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std); + if (rc) + goto bail; + rc = pmac_i2c_xfer(bus, addrdir, 0, 0, NULL, 0); + break; + case I2C_SMBUS_BYTE: + rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std); + if (rc) + goto bail; + rc = pmac_i2c_xfer(bus, addrdir, 0, 0, &data->byte, 1); + break; + case I2C_SMBUS_BYTE_DATA: + rc = pmac_i2c_setmode(bus, read ? + pmac_i2c_mode_combined : + pmac_i2c_mode_stdsub); + if (rc) + goto bail; + rc = pmac_i2c_xfer(bus, addrdir, 1, command, &data->byte, 1); + break; + case I2C_SMBUS_WORD_DATA: + rc = pmac_i2c_setmode(bus, read ? + pmac_i2c_mode_combined : + pmac_i2c_mode_stdsub); + if (rc) + goto bail; + if (!read) { + local[0] = data->word & 0xff; + local[1] = (data->word >> 8) & 0xff; + } + rc = pmac_i2c_xfer(bus, addrdir, 1, command, local, 2); + if (rc == 0 && read) { + data->word = ((u16)local[1]) << 8; + data->word |= local[0]; + } + break; + + /* Note that these are broken vs. the expected smbus API where + * on reads, the lenght 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: + rc = pmac_i2c_setmode(bus, read ? + pmac_i2c_mode_combined : + pmac_i2c_mode_stdsub); + if (rc) + goto bail; + rc = pmac_i2c_xfer(bus, addrdir, 1, command, data->block, + data->block[0] + 1); + + break; + case I2C_SMBUS_I2C_BLOCK_DATA: + rc = pmac_i2c_setmode(bus, read ? + pmac_i2c_mode_combined : + pmac_i2c_mode_stdsub); + if (rc) + goto bail; + rc = pmac_i2c_xfer(bus, addrdir, 1, command, + read ? data->block : &data->block[1], + data->block[0]); + break; + + default: + rc = -EINVAL; + } + 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) + return -EINVAL; + if (msgs->flags & I2C_M_TEN) + return -EINVAL; + read = (msgs->flags & I2C_M_RD) != 0; + addrdir = (msgs->addr << 1) | read; + if (msgs->flags & I2C_M_REV_DIR_ADDR) + addrdir ^= 1; + + rc = pmac_i2c_open(bus, 0); + if (rc) + return rc; + rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std); + if (rc) + goto bail; + rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len); + bail: + pmac_i2c_close(bus); + return rc < 0 ? rc : msgs->len; +} + +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 struct i2c_algorithm i2c_powermac_algorithm = { + .smbus_xfer = i2c_powermac_smbus_xfer, + .master_xfer = i2c_powermac_master_xfer, + .functionality = i2c_powermac_func, +}; + + +static int i2c_powermac_remove(struct device *dev) +{ + struct i2c_adapter *adapter = dev_get_drvdata(dev); + struct pmac_i2c_bus *bus = i2c_get_adapdata(adapter); + int rc; + + rc = i2c_del_adapter(adapter); + pmac_i2c_detach_adapter(bus, adapter); + i2c_set_adapdata(adapter, NULL); + /* We aren't that prepared to deal with this... */ + if (rc) + printk("i2c-powermac.c: Failed to remove bus %s !\n", + adapter->name); + dev_set_drvdata(dev, NULL); + kfree(adapter); + + return 0; +} + + +static int i2c_powermac_probe(struct device *dev) +{ + struct pmac_i2c_bus *bus = dev->platform_data; + struct device_node *parent = NULL; + struct i2c_adapter *adapter; + char name[32], *basename; + int rc; + + if (bus == NULL) + return -EINVAL; + + /* 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(name, 32, "%s %d", basename, pmac_i2c_get_channel(bus)); + of_node_put(parent); + + adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL); + if (adapter == NULL) { + printk(KERN_ERR "i2c-powermac: can't allocate inteface !\n"); + return -ENOMEM; + } + dev_set_drvdata(dev, adapter); + strcpy(adapter->name, name); + adapter->algo = &i2c_powermac_algorithm; + i2c_set_adapdata(adapter, bus); + adapter->dev.parent = dev; + pmac_i2c_attach_adapter(bus, adapter); + rc = i2c_add_adapter(adapter); + if (rc) { + printk(KERN_ERR "i2c-powermac: Adapter %s registration " + "failed\n", name); + i2c_set_adapdata(adapter, NULL); + pmac_i2c_detach_adapter(bus, adapter); + } + + printk(KERN_INFO "PowerMac i2c bus %s registered\n", name); + return rc; +} + + +static struct device_driver i2c_powermac_driver = { + .name = "i2c-powermac", + .bus = &platform_bus_type, + .probe = i2c_powermac_probe, + .remove = i2c_powermac_remove, +}; + +static int __init i2c_powermac_init(void) +{ + driver_register(&i2c_powermac_driver); + return 0; +} + + +static void __exit i2c_powermac_cleanup(void) +{ + driver_unregister(&i2c_powermac_driver); +} + +module_init(i2c_powermac_init); +module_exit(i2c_powermac_cleanup); |