/*
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/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;
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) {
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)
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);
