kernel-ark/drivers/i2c/busses/i2c-via.c
Jean Delvare 3401b2fff3 i2c: Let bus drivers add SPD to their class
Let general purpose I2C/SMBus bus drivers add SPD to their class. Once
this is done, we will be able to tell the eeprom driver to only probe
for SPD EEPROMs and similar on these buses.

Note that I took a conservative approach here, adding I2C_CLASS_SPD to
many drivers that have no idea whether they can host SPD EEPROMs or not.
This is to make sure that the eeprom driver doesn't stop probing buses
where SPD EEPROMs or equivalent live.

So, bus driver maintainers and users should feel free to remove the SPD
class from drivers those buses never have SPD EEPROMs or they don't
want the eeprom driver to bind to them. Likewise, feel free to add the
SPD class to any bus driver I might have missed.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-07-14 22:38:29 +02:00

185 lines
4.5 KiB
C

/*
i2c-via.c - Part of lm_sensors, Linux kernel modules
for hardware monitoring
i2c Support for Via Technologies 82C586B South Bridge
Copyright (c) 1998, 1999 Kyösti Mälkki <kmalkki@cc.hut.fi>
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/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-bit.h>
#include <asm/io.h>
/* Power management registers */
#define PM_CFG_REVID 0x08 /* silicon revision code */
#define PM_CFG_IOBASE0 0x20
#define PM_CFG_IOBASE1 0x48
#define I2C_DIR (pm_io_base+0x40)
#define I2C_OUT (pm_io_base+0x42)
#define I2C_IN (pm_io_base+0x44)
#define I2C_SCL 0x02 /* clock bit in DIR/OUT/IN register */
#define I2C_SDA 0x04
/* io-region reservation */
#define IOSPACE 0x06
static struct pci_driver vt586b_driver;
static u16 pm_io_base;
/*
It does not appear from the datasheet that the GPIO pins are
open drain. So a we set a low value by setting the direction to
output and a high value by setting the direction to input and
relying on the required I2C pullup. The data value is initialized
to 0 in via_init() and never changed.
*/
static void bit_via_setscl(void *data, int state)
{
outb(state ? inb(I2C_DIR) & ~I2C_SCL : inb(I2C_DIR) | I2C_SCL, I2C_DIR);
}
static void bit_via_setsda(void *data, int state)
{
outb(state ? inb(I2C_DIR) & ~I2C_SDA : inb(I2C_DIR) | I2C_SDA, I2C_DIR);
}
static int bit_via_getscl(void *data)
{
return (0 != (inb(I2C_IN) & I2C_SCL));
}
static int bit_via_getsda(void *data)
{
return (0 != (inb(I2C_IN) & I2C_SDA));
}
static struct i2c_algo_bit_data bit_data = {
.setsda = bit_via_setsda,
.setscl = bit_via_setscl,
.getsda = bit_via_getsda,
.getscl = bit_via_getscl,
.udelay = 5,
.timeout = HZ
};
static struct i2c_adapter vt586b_adapter = {
.owner = THIS_MODULE,
.id = I2C_HW_B_VIA,
.class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
.name = "VIA i2c",
.algo_data = &bit_data,
};
static struct pci_device_id vt586b_ids[] __devinitdata = {
{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C586_3) },
{ 0, }
};
MODULE_DEVICE_TABLE (pci, vt586b_ids);
static int __devinit vt586b_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
u16 base;
u8 rev;
int res;
if (pm_io_base) {
dev_err(&dev->dev, "i2c-via: Will only support one host\n");
return -ENODEV;
}
pci_read_config_byte(dev, PM_CFG_REVID, &rev);
switch (rev) {
case 0x00:
base = PM_CFG_IOBASE0;
break;
case 0x01:
case 0x10:
base = PM_CFG_IOBASE1;
break;
default:
base = PM_CFG_IOBASE1;
/* later revision */
}
pci_read_config_word(dev, base, &pm_io_base);
pm_io_base &= (0xff << 8);
if (!request_region(I2C_DIR, IOSPACE, vt586b_driver.name)) {
dev_err(&dev->dev, "IO 0x%x-0x%x already in use\n", I2C_DIR, I2C_DIR + IOSPACE);
return -ENODEV;
}
outb(inb(I2C_DIR) & ~(I2C_SDA | I2C_SCL), I2C_DIR);
outb(inb(I2C_OUT) & ~(I2C_SDA | I2C_SCL), I2C_OUT);
/* set up the sysfs linkage to our parent device */
vt586b_adapter.dev.parent = &dev->dev;
res = i2c_bit_add_bus(&vt586b_adapter);
if ( res < 0 ) {
release_region(I2C_DIR, IOSPACE);
pm_io_base = 0;
return res;
}
return 0;
}
static void __devexit vt586b_remove(struct pci_dev *dev)
{
i2c_del_adapter(&vt586b_adapter);
release_region(I2C_DIR, IOSPACE);
pm_io_base = 0;
}
static struct pci_driver vt586b_driver = {
.name = "vt586b_smbus",
.id_table = vt586b_ids,
.probe = vt586b_probe,
.remove = __devexit_p(vt586b_remove),
};
static int __init i2c_vt586b_init(void)
{
return pci_register_driver(&vt586b_driver);
}
static void __exit i2c_vt586b_exit(void)
{
pci_unregister_driver(&vt586b_driver);
}
MODULE_AUTHOR("Kyösti Mälkki <kmalkki@cc.hut.fi>");
MODULE_DESCRIPTION("i2c for Via vt82c586b southbridge");
MODULE_LICENSE("GPL");
module_init(i2c_vt586b_init);
module_exit(i2c_vt586b_exit);