// SPDX-License-Identifier: GPL-2.0-or-later
/*
i2c Support for Apple SMU Controller
Copyright (c) 2005 Benjamin Herrenschmidt, IBM Corp.
<benh@kernel.crashing.org>
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/i2c.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/of_irq.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) {
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 addrdir;
if (msgs->flags & I2C_M_TEN)
return -EINVAL;
addrdir = i2c_8bit_addr_from_msg(msgs);
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 const struct i2c_adapter_quirks i2c_powermac_quirks = {
.max_num_msgs = 1,
};
static int i2c_powermac_remove(struct platform_device *dev)
{
struct i2c_adapter *adapter = platform_get_drvdata(dev);
i2c_del_adapter(adapter);
memset(adapter, 0, sizeof(*adapter));
return 0;
}
static u32 i2c_powermac_get_addr(struct i2c_adapter *adap,
struct pmac_i2c_bus *bus,
struct device_node *node)
{
const __be32 *prop;
int len;
/* First check for valid "reg" */
prop = of_get_property(node, "reg", &len);
if (prop && (len >= sizeof(int)))
return (be32_to_cpup(prop) & 0xff) >> 1;
/* Then check old-style "i2c-address" */
prop = of_get_property(node, "i2c-address", &len);
if (prop && (len >= sizeof(int)))
return (be32_to_cpup(prop) & 0xff) >> 1;
/* Now handle some devices with missing "reg" properties */
if (of_node_name_eq(node, "cereal"))
return 0x60;
else if (of_node_name_eq(node, "deq"))
return 0x34;
dev_warn(&adap->dev, "No i2c address for %pOF\n", node);
return 0xffffffff;
}
static void i2c_powermac_create_one(struct i2c_adapter *adap,
const char *type,
u32 addr)
{
struct i2c_board_info info = {};
struct i2c_client *newdev;
strncpy(info.type, type, sizeof(info.type));
info.addr = addr;
newdev = i2c_new_device(adap, &info);
if (!newdev)
dev_err(&adap->dev,
"i2c-powermac: Failure to register missing %s\n",
type);
}
static void i2c_powermac_add_missing(struct i2c_adapter *adap,
struct pmac_i2c_bus *bus,
bool found_onyx)
{
struct device_node *busnode = pmac_i2c_get_bus_node(bus);
int rc;
/* Check for the onyx audio codec */
#define ONYX_REG_CONTROL 67
if (of_device_is_compatible(busnode, "k2-i2c") && !found_onyx) {
union i2c_smbus_data data;
rc = i2c_smbus_xfer(adap, 0x46, 0, I2C_SMBUS_READ,
ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
&data);
if (rc >= 0)
i2c_powermac_create_one(adap, "MAC,pcm3052", 0x46);
rc = i2c_smbus_xfer(adap, 0x47, 0, I2C_SMBUS_READ,
ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
&data);
if (rc >= 0)
i2c_powermac_create_one(adap, "MAC,pcm3052", 0x47);
}
}
static bool i2c_powermac_get_type(struct i2c_adapter *adap,
struct device_node *node,
u32 addr, char *type, int type_size)
{
char tmp[16];
/* Note: we to _NOT_ want the standard
* i2c drivers to match with any of our powermac stuff
* unless they have been specifically modified to handle
* it on a case by case basis. For example, for thermal
* control, things like lm75 etc... shall match with their
* corresponding windfarm drivers, _NOT_ the generic ones,
* so we force a prefix of AAPL, onto the modalias to
* make that happen
*/
/* First try proper modalias */
if (of_modalias_node(node, tmp, sizeof(tmp)) >= 0) {
snprintf(type, type_size, "MAC,%s", tmp);
return true;
}
/* Now look for known workarounds */
if (of_node_name_eq(node, "deq")) {
/* Apple uses address 0x34 for TAS3001 and 0x35 for TAS3004 */
if (addr == 0x34) {
snprintf(type, type_size, "MAC,tas3001");
return true;
} else if (addr == 0x35) {
snprintf(type, type_size, "MAC,tas3004");
return true;
}
}
dev_err(&adap->dev, "i2c-powermac: modalias failure on %pOF\n", node);
return false;
}
static void i2c_powermac_register_devices(struct i2c_adapter *adap,
struct pmac_i2c_bus *bus)
{
struct i2c_client *newdev;
struct device_node *node;
bool found_onyx = 0;
/*
* In some cases we end up with the via-pmu node itself, in this
* case we skip this function completely as the device-tree will
* not contain anything useful.
*/
if (of_node_name_eq(adap->dev.of_node, "via-pmu"))
return;
for_each_child_of_node(adap->dev.of_node, node) {
struct i2c_board_info info = {};
u32 addr;
/* Get address & channel */
addr = i2c_powermac_get_addr(adap, bus, node);
if (addr == 0xffffffff)
continue;
/* Multibus setup, check channel */
if (!pmac_i2c_match_adapter(node, adap))
continue;
dev_dbg(&adap->dev, "i2c-powermac: register %pOF\n", node);
/*
* Keep track of some device existence to handle
* workarounds later.
*/
if (of_device_is_compatible(node, "pcm3052"))
found_onyx = true;
/* Make up a modalias */
if (!i2c_powermac_get_type(adap, node, addr,
info.type, sizeof(info.type))) {
continue;
}
/* Fill out the rest of the info structure */
info.addr = addr;
info.irq = irq_of_parse_and_map(node, 0);
info.of_node = of_node_get(node);
newdev = i2c_new_device(adap, &info);
if (!newdev) {
dev_err(&adap->dev, "i2c-powermac: Failure to register"
" %pOF\n", node);
of_node_put(node);
/* We do not dispose of the interrupt mapping on
* purpose. It's not necessary (interrupt cannot be
* re-used) and somebody else might have grabbed it
* via direct DT lookup so let's not bother
*/
continue;
}
}
/* Additional workarounds */
i2c_powermac_add_missing(adap, bus, found_onyx);
}
static int i2c_powermac_probe(struct platform_device *dev)
{
struct pmac_i2c_bus *bus = dev_get_platdata(&dev->dev);
struct device_node *parent;
struct i2c_adapter *adapter;
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;
snprintf(adapter->name, sizeof(adapter->name), "%pOFn %d",
parent,
pmac_i2c_get_channel(bus));
of_node_put(parent);
break;
case pmac_i2c_bus_pmu:
snprintf(adapter->name, sizeof(adapter->name), "pmu %d",
pmac_i2c_get_channel(bus));
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
*/
snprintf(adapter->name, sizeof(adapter->name), "smu %d",
pmac_i2c_get_channel(bus));
break;
default:
return -EINVAL;
}
platform_set_drvdata(dev, adapter);
adapter->algo = &i2c_powermac_algorithm;
adapter->quirks = &i2c_powermac_quirks;
i2c_set_adapdata(adapter, bus);
adapter->dev.parent = &dev->dev;
/* Clear of_node to skip automatic registration of i2c child nodes */
adapter->dev.of_node = NULL;
rc = i2c_add_adapter(adapter);
if (rc) {
printk(KERN_ERR "i2c-powermac: Adapter %s registration "
"failed\n", adapter->name);
memset(adapter, 0, sizeof(*adapter));
return rc;
}
printk(KERN_INFO "PowerMac i2c bus %s registered\n", adapter->name);
/* Use custom child registration due to Apple device-tree funkyness */
adapter->dev.of_node = dev->dev.of_node;
i2c_powermac_register_devices(adapter, bus);
return 0;
}
static struct platform_driver i2c_powermac_driver = {
.probe = i2c_powermac_probe,
.remove = i2c_powermac_remove,
.driver = {
.name = "i2c-powermac",
.bus = &platform_bus_type,
},
};
module_platform_driver(i2c_powermac_driver);
MODULE_ALIAS("platform:i2c-powermac");
