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/* bbc_i2c.c: I2C low-level driver for BBC device on UltraSPARC-III
* platforms.
*
* Copyright (C) 2001, 2008 David S. Miller (davem@davemloft.net)
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <asm/bbc.h>
#include <asm/io.h>
#include "bbc_i2c.h"
/* Convert this driver to use i2c bus layer someday... */
#define I2C_PCF_PIN 0x80
#define I2C_PCF_ESO 0x40
#define I2C_PCF_ES1 0x20
#define I2C_PCF_ES2 0x10
#define I2C_PCF_ENI 0x08
#define I2C_PCF_STA 0x04
#define I2C_PCF_STO 0x02
#define I2C_PCF_ACK 0x01
#define I2C_PCF_START (I2C_PCF_PIN | I2C_PCF_ESO | I2C_PCF_ENI | I2C_PCF_STA | I2C_PCF_ACK)
#define I2C_PCF_STOP (I2C_PCF_PIN | I2C_PCF_ESO | I2C_PCF_STO | I2C_PCF_ACK)
#define I2C_PCF_REPSTART ( I2C_PCF_ESO | I2C_PCF_STA | I2C_PCF_ACK)
#define I2C_PCF_IDLE (I2C_PCF_PIN | I2C_PCF_ESO | I2C_PCF_ACK)
#define I2C_PCF_INI 0x40 /* 1 if not initialized */
#define I2C_PCF_STS 0x20
#define I2C_PCF_BER 0x10
#define I2C_PCF_AD0 0x08
#define I2C_PCF_LRB 0x08
#define I2C_PCF_AAS 0x04
#define I2C_PCF_LAB 0x02
#define I2C_PCF_BB 0x01
/* The BBC devices have two I2C controllers. The first I2C controller
* connects mainly to configuration proms (NVRAM, cpu configuration,
* dimm types, etc.). Whereas the second I2C controller connects to
* environmental control devices such as fans and temperature sensors.
* The second controller also connects to the smartcard reader, if present.
*/
static void set_device_claimage(struct bbc_i2c_bus *bp, struct platform_device *op, int val)
{
int i;
for (i = 0; i < NUM_CHILDREN; i++) {
if (bp->devs[i].device == op) {
bp->devs[i].client_claimed = val;
return;
}
}
}
#define claim_device(BP,ECHILD) set_device_claimage(BP,ECHILD,1)
#define release_device(BP,ECHILD) set_device_claimage(BP,ECHILD,0)
struct platform_device *bbc_i2c_getdev(struct bbc_i2c_bus *bp, int index)
{
struct platform_device *op = NULL;
int curidx = 0, i;
for (i = 0; i < NUM_CHILDREN; i++) {
if (!(op = bp->devs[i].device))
break;
if (curidx == index)
goto out;
op = NULL;
curidx++;
}
out:
if (curidx == index)
return op;
return NULL;
}
struct bbc_i2c_client *bbc_i2c_attach(struct bbc_i2c_bus *bp, struct platform_device *op)
{
struct bbc_i2c_client *client;
const u32 *reg;
client = kzalloc(sizeof(*client), GFP_KERNEL);
if (!client)
return NULL;
client->bp = bp;
client->op = op;
reg = of_get_property(op->dev.of_node, "reg", NULL);
if (!reg) {
kfree(client);
return NULL;
}
client->bus = reg[0];
client->address = reg[1];
claim_device(bp, op);
return client;
}
void bbc_i2c_detach(struct bbc_i2c_client *client)
{
struct bbc_i2c_bus *bp = client->bp;
struct platform_device *op = client->op;
release_device(bp, op);
kfree(client);
}
static int wait_for_pin(struct bbc_i2c_bus *bp, u8 *status)
{
DECLARE_WAITQUEUE(wait, current);
int limit = 32;
int ret = 1;
bp->waiting = 1;
add_wait_queue(&bp->wq, &wait);
while (limit-- > 0) {
long val;
val = wait_event_interruptible_timeout(
bp->wq,
(((*status = readb(bp->i2c_control_regs + 0))
& I2C_PCF_PIN) == 0),
msecs_to_jiffies(250));
if (val > 0) {
ret = 0;
break;
}
}
remove_wait_queue(&bp->wq, &wait);
bp->waiting = 0;
return ret;
}
int bbc_i2c_writeb(struct bbc_i2c_client *client, unsigned char val, int off)
{
struct bbc_i2c_bus *bp = client->bp;
int address = client->address;
u8 status;
int ret = -1;
if (bp->i2c_bussel_reg != NULL)
writeb(client->bus, bp->i2c_bussel_reg);
writeb(address, bp->i2c_control_regs + 0x1);
writeb(I2C_PCF_START, bp->i2c_control_regs + 0x0);
if (wait_for_pin(bp, &status))
goto out;
writeb(off, bp->i2c_control_regs + 0x1);
if (wait_for_pin(bp, &status) ||
(status & I2C_PCF_LRB) != 0)
goto out;
writeb(val, bp->i2c_control_regs + 0x1);
if (wait_for_pin(bp, &status))
goto out;
ret = 0;
out:
writeb(I2C_PCF_STOP, bp->i2c_control_regs + 0x0);
return ret;
}
int bbc_i2c_readb(struct bbc_i2c_client *client, unsigned char *byte, int off)
{
struct bbc_i2c_bus *bp = client->bp;
unsigned char address = client->address, status;
int ret = -1;
if (bp->i2c_bussel_reg != NULL)
writeb(client->bus, bp->i2c_bussel_reg);
writeb(address, bp->i2c_control_regs + 0x1);
writeb(I2C_PCF_START, bp->i2c_control_regs + 0x0);
if (wait_for_pin(bp, &status))
goto out;
writeb(off, bp->i2c_control_regs + 0x1);
if (wait_for_pin(bp, &status) ||
(status & I2C_PCF_LRB) != 0)
goto out;
writeb(I2C_PCF_STOP, bp->i2c_control_regs + 0x0);
address |= 0x1; /* READ */
writeb(address, bp->i2c_control_regs + 0x1);
writeb(I2C_PCF_START, bp->i2c_control_regs + 0x0);
if (wait_for_pin(bp, &status))
goto out;
/* Set PIN back to one so the device sends the first
* byte.
*/
(void) readb(bp->i2c_control_regs + 0x1);
if (wait_for_pin(bp, &status))
goto out;
writeb(I2C_PCF_ESO | I2C_PCF_ENI, bp->i2c_control_regs + 0x0);
*byte = readb(bp->i2c_control_regs + 0x1);
if (wait_for_pin(bp, &status))
goto out;
ret = 0;
out:
writeb(I2C_PCF_STOP, bp->i2c_control_regs + 0x0);
(void) readb(bp->i2c_control_regs + 0x1);
return ret;
}
int bbc_i2c_write_buf(struct bbc_i2c_client *client,
char *buf, int len, int off)
{
int ret = 0;
while (len > 0) {
ret = bbc_i2c_writeb(client, *buf, off);
if (ret < 0)
break;
len--;
buf++;
off++;
}
return ret;
}
int bbc_i2c_read_buf(struct bbc_i2c_client *client,
char *buf, int len, int off)
{
int ret = 0;
while (len > 0) {
ret = bbc_i2c_readb(client, buf, off);
if (ret < 0)
break;
len--;
buf++;
off++;
}
return ret;
}
EXPORT_SYMBOL(bbc_i2c_getdev);
EXPORT_SYMBOL(bbc_i2c_attach);
EXPORT_SYMBOL(bbc_i2c_detach);
EXPORT_SYMBOL(bbc_i2c_writeb);
EXPORT_SYMBOL(bbc_i2c_readb);
EXPORT_SYMBOL(bbc_i2c_write_buf);
EXPORT_SYMBOL(bbc_i2c_read_buf);
static irqreturn_t bbc_i2c_int
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