/*
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/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 (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 : 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 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];
const char *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);
