+++ /dev/null
-/*
- * i2c-algo-sgi.c: i2c driver algorithm used by the VINO (SGI Indy) and
- * MACE (SGI O2) chips.
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License version 2 as published by the Free Software Foundation.
- *
- * Copyright (C) 2003 Ladislav Michl <ladis@linux-mips.org>
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/errno.h>
-#include <linux/delay.h>
-
-#include <linux/i2c.h>
-#include <linux/i2c-algo-sgi.h>
-
-
-#define SGI_I2C_FORCE_IDLE (0 << 0)
-#define SGI_I2C_NOT_IDLE (1 << 0)
-#define SGI_I2C_WRITE (0 << 1)
-#define SGI_I2C_READ (1 << 1)
-#define SGI_I2C_RELEASE_BUS (0 << 2)
-#define SGI_I2C_HOLD_BUS (1 << 2)
-#define SGI_I2C_XFER_DONE (0 << 4)
-#define SGI_I2C_XFER_BUSY (1 << 4)
-#define SGI_I2C_ACK (0 << 5)
-#define SGI_I2C_NACK (1 << 5)
-#define SGI_I2C_BUS_OK (0 << 7)
-#define SGI_I2C_BUS_ERR (1 << 7)
-
-#define get_control() adap->getctrl(adap->data)
-#define set_control(val) adap->setctrl(adap->data, val)
-#define read_data() adap->rdata(adap->data)
-#define write_data(val) adap->wdata(adap->data, val)
-
-
-static int wait_xfer_done(struct i2c_algo_sgi_data *adap)
-{
- int i;
-
- for (i = 0; i < adap->xfer_timeout; i++) {
- if ((get_control() & SGI_I2C_XFER_BUSY) == 0)
- return 0;
- udelay(1);
- }
-
- return -ETIMEDOUT;
-}
-
-static int wait_ack(struct i2c_algo_sgi_data *adap)
-{
- int i;
-
- if (wait_xfer_done(adap))
- return -ETIMEDOUT;
- for (i = 0; i < adap->ack_timeout; i++) {
- if ((get_control() & SGI_I2C_NACK) == 0)
- return 0;
- udelay(1);
- }
-
- return -ETIMEDOUT;
-}
-
-static int force_idle(struct i2c_algo_sgi_data *adap)
-{
- int i;
-
- set_control(SGI_I2C_FORCE_IDLE);
- for (i = 0; i < adap->xfer_timeout; i++) {
- if ((get_control() & SGI_I2C_NOT_IDLE) == 0)
- goto out;
- udelay(1);
- }
- return -ETIMEDOUT;
-out:
- if (get_control() & SGI_I2C_BUS_ERR)
- return -EIO;
- return 0;
-}
-
-static int do_address(struct i2c_algo_sgi_data *adap, unsigned int addr,
- int rd)
-{
- if (rd)
- set_control(SGI_I2C_NOT_IDLE);
- /* Check if bus is idle, eventually force it to do so */
- if (get_control() & SGI_I2C_NOT_IDLE)
- if (force_idle(adap))
- return -EIO;
- /* Write out the i2c chip address and specify operation */
- set_control(SGI_I2C_HOLD_BUS | SGI_I2C_WRITE | SGI_I2C_NOT_IDLE);
- if (rd)
- addr |= 1;
- write_data(addr);
- if (wait_ack(adap))
- return -EIO;
- return 0;
-}
-
-static int i2c_read(struct i2c_algo_sgi_data *adap, unsigned char *buf,
- unsigned int len)
-{
- int i;
-
- set_control(SGI_I2C_HOLD_BUS | SGI_I2C_READ | SGI_I2C_NOT_IDLE);
- for (i = 0; i < len; i++) {
- if (wait_xfer_done(adap))
- return -EIO;
- buf[i] = read_data();
- }
- set_control(SGI_I2C_RELEASE_BUS | SGI_I2C_FORCE_IDLE);
-
- return 0;
-
-}
-
-static int i2c_write(struct i2c_algo_sgi_data *adap, unsigned char *buf,
- unsigned int len)
-{
- int i;
-
- /* We are already in write state */
- for (i = 0; i < len; i++) {
- write_data(buf[i]);
- if (wait_ack(adap))
- return -EIO;
- }
- return 0;
-}
-
-static int sgi_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs,
- int num)
-{
- struct i2c_algo_sgi_data *adap = i2c_adap->algo_data;
- struct i2c_msg *p;
- int i, err = 0;
-
- for (i = 0; !err && i < num; i++) {
- p = &msgs[i];
- err = do_address(adap, p->addr, p->flags & I2C_M_RD);
- if (err || !p->len)
- continue;
- if (p->flags & I2C_M_RD)
- err = i2c_read(adap, p->buf, p->len);
- else
- err = i2c_write(adap, p->buf, p->len);
- }
-
- return (err < 0) ? err : i;
-}
-
-static u32 sgi_func(struct i2c_adapter *adap)
-{
- return I2C_FUNC_SMBUS_EMUL;
-}
-
-static const struct i2c_algorithm sgi_algo = {
- .master_xfer = sgi_xfer,
- .functionality = sgi_func,
-};
-
-/*
- * registering functions to load algorithms at runtime
- */
-int i2c_sgi_add_bus(struct i2c_adapter *adap)
-{
- adap->algo = &sgi_algo;
-
- return i2c_add_adapter(adap);
-}
-EXPORT_SYMBOL(i2c_sgi_add_bus);
-
-MODULE_AUTHOR("Ladislav Michl <ladis@linux-mips.org>");
-MODULE_DESCRIPTION("I2C-Bus SGI algorithm");
-MODULE_LICENSE("GPL");