diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-via.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-via.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-via.c b/drivers/i2c/busses/i2c-via.c new file mode 100644 index 000000000000..2cbc4cd22366 --- /dev/null +++ b/drivers/i2c/busses/i2c-via.c @@ -0,0 +1,185 @@ +/* + 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/config.h> +#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 +#define IOTEXT "via-i2c" + +static u16 pm_io_base = 0; + +/* + 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, + .mdelay = 5, + .timeout = HZ +}; + +static struct i2c_adapter vt586b_adapter = { + .owner = THIS_MODULE, + .class = I2C_CLASS_HWMON, + .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, IOTEXT)) { + 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 driverfs 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_bit_del_bus(&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); |